Science.gov

Sample records for modeling human interaction

  1. Cyberpsychology: a human-interaction perspective based on cognitive modeling.

    PubMed

    Emond, Bruno; West, Robert L

    2003-10-01

    This paper argues for the relevance of cognitive modeling and cognitive architectures to cyberpsychology. From a human-computer interaction point of view, cognitive modeling can have benefits both for theory and model building, and for the design and evaluation of sociotechnical systems usability. Cognitive modeling research applied to human-computer interaction has two complimentary objectives: (1) to develop theories and computational models of human interactive behavior with information and collaborative technologies, and (2) to use the computational models as building blocks for the design, implementation, and evaluation of interactive technologies. From the perspective of building theories and models, cognitive modeling offers the possibility to anchor cyberpsychology theories and models into cognitive architectures. From the perspective of the design and evaluation of socio-technical systems, cognitive models can provide the basis for simulated users, which can play an important role in usability testing. As an example of application of cognitive modeling to technology design, the paper presents a simulation of interactive behavior with five different adaptive menu algorithms: random, fixed, stacked, frequency based, and activation based. Results of the simulation indicate that fixed menu positions seem to offer the best support for classification like tasks such as filing e-mails. This research is part of the Human-Computer Interaction, and the Broadband Visual Communication research programs at the National Research Council of Canada, in collaboration with the Carleton Cognitive Modeling Lab at Carleton University.

  2. The GOURD model of human-computer interaction

    SciTech Connect

    Goldbogen, G.

    1996-12-31

    This paper presents a model, the GOURD model, that can be used to measure the goodness of {open_quotes}interactivity{close_quotes} of an interface design and qualifies how to improve the design. The GOURD model describes what happens to the computer and to the human during a human-computer interaction. Since the interaction is generally repeated, the traversal of the model repeatedly is similar to a loop programming structure. Because the model measures interaction over part or all of the application, it can also be used as a classifier of the part or the whole application. But primarily, the model is used as a design guide and a predictor of effectiveness.

  3. Modeling Human Dynamics of Face-to-Face Interaction Networks

    NASA Astrophysics Data System (ADS)

    Starnini, Michele; Baronchelli, Andrea; Pastor-Satorras, Romualdo

    2013-04-01

    Face-to-face interaction networks describe social interactions in human gatherings, and are the substrate for processes such as epidemic spreading and gossip propagation. The bursty nature of human behavior characterizes many aspects of empirical data, such as the distribution of conversation lengths, of conversations per person, or of interconversation times. Despite several recent attempts, a general theoretical understanding of the global picture emerging from data is still lacking. Here we present a simple model that reproduces quantitatively most of the relevant features of empirical face-to-face interaction networks. The model describes agents that perform a random walk in a two-dimensional space and are characterized by an attractiveness whose effect is to slow down the motion of people around them. The proposed framework sheds light on the dynamics of human interactions and can improve the modeling of dynamical processes taking place on the ensuing dynamical social networks.

  4. A Human View Model for Socio-Technical Interactions

    NASA Technical Reports Server (NTRS)

    Handley, Holly A.; Tolk, Andreas

    2012-01-01

    The Human View was developed as an additional architectural viewpoint to focus on the human part of a system. The Human View can be used to collect and organize data in order to understand how human operators interact and impact the other elements of a system. This framework can also be used to develop a model to describe how humans interact with each other in network enabled systems. These socio-technical interactions form the foundation of the emerging area of Human Interoperability. Human Interoperability strives to understand the relationships required between human operators that impact collaboration across networked environments, including the effect of belonging to different organizations. By applying organizational relationship concepts from network theory to the Human View elements, and aligning these relationships with a model developed to identify layers of coalition interoperability, the conditions for different levels for Human Interoperability for network enabled systems can be identified. These requirements can then be captured in the Human View products to improve the overall network enabled system.

  5. Intuitive Cognition and Models of Human-Automation Interaction.

    PubMed

    Patterson, Robert Earl

    2017-02-01

    The aim of this study was to provide an analysis of the implications of the dominance of intuitive cognition in human reasoning and decision making for conceptualizing models and taxonomies of human-automation interaction, focusing on the Parasuraman et al. model and taxonomy. Knowledge about how humans reason and make decisions, which has been shown to be largely intuitive, has implications for the design of future human-machine systems. One hundred twenty articles and books cited in other works as well as those obtained from an Internet search were reviewed. Works were deemed eligible if they were published within the past 50 years and common to a given literature. Analysis shows that intuitive cognition dominates human reasoning and decision making in all situations examined. The implications of the dominance of intuitive cognition for the Parasuraman et al. model and taxonomy are discussed. A taxonomy of human-automation interaction that incorporates intuitive cognition is suggested. Understanding the ways in which human reasoning and decision making is intuitive can provide insight for future models and taxonomies of human-automation interaction.

  6. A Qualitative Model of Human Interaction with Complex Dynamic Systems

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.

    1987-01-01

    A qualitative model describing human interaction with complex dynamic systems is developed. The model is hierarchical in nature and consists of three parts: a behavior generator, an internal model, and a sensory information processor. The behavior generator is responsible for action decomposition, turning higher level goals or missions into physical action at the human-machine interface. The internal model is an internal representation of the environment which the human is assumed to possess and is divided into four submodel categories. The sensory information processor is responsible for sensory composition. All three parts of the model act in consort to allow anticipatory behavior on the part of the human in goal-directed interaction with dynamic systems. Human workload and error are interpreted in this framework, and the familiar example of an automobile commute is used to illustrate the nature of the activity in the three model elements. Finally, with the qualitative model as a guide, verbal protocols from a manned simulation study of a helicopter instrument landing task are analyzed with particular emphasis on the effect of automation on human-machine performance.

  7. A qualitative model of human interaction with complex dynamic systems

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.

    1987-01-01

    A qualitative model describing human interaction with complex dynamic systems is developed. The model is hierarchical in nature and consists of three parts: a behavior generator, an internal model, and a sensory information processor. The behavior generator is responsible for action decomposition, turning higher level goals or missions into physical action at the human-machine interface. The internal model is an internal representation of the environment which the human is assumed to possess and is divided into four submodel categories. The sensory information processor is responsible for sensory composition. All three parts of the model act in consort to allow anticipatory behavior on the part of the human in goal-directed interaction with dynamic systems. Human workload and error are interpreted in this framework, and the familiar example of an automobile commute is used to illustrate the nature of the activity in the three model elements. Finally, with the qualitative model as a guide, verbal protocols from a manned simulation study of a helicopter instrument landing task are analyzed with particular emphasis on the effect of automation on human-machine performance.

  8. Quantitative Modeling of Human-Environment Interactions in Preindustrial Time

    NASA Astrophysics Data System (ADS)

    Sommer, Philipp S.; Kaplan, Jed O.

    2017-04-01

    Quantifying human-environment interactions and anthropogenic influences on the environment prior to the Industrial revolution is essential for understanding the current state of the earth system. This is particularly true for the terrestrial biosphere, but marine ecosystems and even climate were likely modified by human activities centuries to millennia ago. Direct observations are however very sparse in space and time, especially as one considers prehistory. Numerical models are therefore essential to produce a continuous picture of human-environment interactions in the past. Agent-based approaches, while widely applied to quantifying human influence on the environment in localized studies, are unsuitable for global spatial domains and Holocene timescales because of computational demands and large parameter uncertainty. Here we outline a new paradigm for the quantitative modeling of human-environment interactions in preindustrial time that is adapted to the global Holocene. Rather than attempting to simulate agency directly, the model is informed by a suite of characteristics describing those things about society that cannot be predicted on the basis of environment, e.g., diet, presence of agriculture, or range of animals exploited. These categorical data are combined with the properties of the physical environment in coupled human-environment model. The model is, at its core, a dynamic global vegetation model with a module for simulating crop growth that is adapted for preindustrial agriculture. This allows us to simulate yield and calories for feeding both humans and their domesticated animals. We couple this basic caloric availability with a simple demographic model to calculate potential population, and, constrained by labor requirements and land limitations, we create scenarios of land use and land cover on a moderate-resolution grid. We further implement a feedback loop where anthropogenic activities lead to changes in the properties of the physical

  9. Kernel method based human model for enhancing interactive evolutionary optimization.

    PubMed

    Pei, Yan; Zhao, Qiangfu; Liu, Yong

    2015-01-01

    A fitness landscape presents the relationship between individual and its reproductive success in evolutionary computation (EC). However, discrete and approximate landscape in an original search space may not support enough and accurate information for EC search, especially in interactive EC (IEC). The fitness landscape of human subjective evaluation in IEC is very difficult and impossible to model, even with a hypothesis of what its definition might be. In this paper, we propose a method to establish a human model in projected high dimensional search space by kernel classification for enhancing IEC search. Because bivalent logic is a simplest perceptual paradigm, the human model is established by considering this paradigm principle. In feature space, we design a linear classifier as a human model to obtain user preference knowledge, which cannot be supported linearly in original discrete search space. The human model is established by this method for predicting potential perceptual knowledge of human. With the human model, we design an evolution control method to enhance IEC search. From experimental evaluation results with a pseudo-IEC user, our proposed model and method can enhance IEC search significantly.

  10. Kernel Method Based Human Model for Enhancing Interactive Evolutionary Optimization

    PubMed Central

    Zhao, Qiangfu; Liu, Yong

    2015-01-01

    A fitness landscape presents the relationship between individual and its reproductive success in evolutionary computation (EC). However, discrete and approximate landscape in an original search space may not support enough and accurate information for EC search, especially in interactive EC (IEC). The fitness landscape of human subjective evaluation in IEC is very difficult and impossible to model, even with a hypothesis of what its definition might be. In this paper, we propose a method to establish a human model in projected high dimensional search space by kernel classification for enhancing IEC search. Because bivalent logic is a simplest perceptual paradigm, the human model is established by considering this paradigm principle. In feature space, we design a linear classifier as a human model to obtain user preference knowledge, which cannot be supported linearly in original discrete search space. The human model is established by this method for predicting potential perceptual knowledge of human. With the human model, we design an evolution control method to enhance IEC search. From experimental evaluation results with a pseudo-IEC user, our proposed model and method can enhance IEC search significantly. PMID:25879050

  11. Reduced-order models for vertical human-structure interaction

    NASA Astrophysics Data System (ADS)

    Van Nimmen, Katrien; Lombaert, Geert; De Roeck, Guido; Van den Broeck, Peter

    2016-09-01

    For slender and lightweight structures, the vibration serviceability under crowd- induced loading is often critical in design. Currently, designers rely on equivalent load models, upscaled from single-person force measurements. Furthermore, it is important to consider the mechanical interaction with the human body as this can significantly reduce the structural response. To account for these interaction effects, the contact force between the pedestrian and the structure can be modelled as the superposition of the force induced by the pedestrian on a rigid floor and the force resulting from the mechanical interaction between the structure and the human body. For the case of large crowds, however, this approach leads to models with a very high system order. In the present contribution, two equivalent reduced-order models are proposed to approximate the dynamic behaviour of the full-order coupled crowd-structure system. A numerical study is performed to evaluate the impact of the modelling assumptions on the structural response to pedestrian excitation. The results show that the full-order moving crowd model can be well approximated by a reduced-order model whereby the interaction with the pedestrians in the crowd is modelled using a single (equivalent) SDOF system.

  12. Identifying and modeling the structural discontinuities of human interactions

    PubMed Central

    Grauwin, Sebastian; Szell, Michael; Sobolevsky, Stanislav; Hövel, Philipp; Simini, Filippo; Vanhoof, Maarten; Smoreda, Zbigniew; Barabási, Albert-László; Ratti, Carlo

    2017-01-01

    The idea of a hierarchical spatial organization of society lies at the core of seminal theories in human geography that have strongly influenced our understanding of social organization. Along the same line, the recent availability of large-scale human mobility and communication data has offered novel quantitative insights hinting at a strong geographical confinement of human interactions within neighboring regions, extending to local levels within countries. However, models of human interaction largely ignore this effect. Here, we analyze several country-wide networks of telephone calls - both, mobile and landline - and in either case uncover a systematic decrease of communication induced by borders which we identify as the missing variable in state-of-the-art models. Using this empirical evidence, we propose an alternative modeling framework that naturally stylizes the damping effect of borders. We show that this new notion substantially improves the predictive power of widely used interaction models. This increases our ability to understand, model and predict social activities and to plan the development of infrastructures across multiple scales. PMID:28443647

  13. Identifying and modeling the structural discontinuities of human interactions

    NASA Astrophysics Data System (ADS)

    Grauwin, Sebastian; Szell, Michael; Sobolevsky, Stanislav; Hövel, Philipp; Simini, Filippo; Vanhoof, Maarten; Smoreda, Zbigniew; Barabási, Albert-László; Ratti, Carlo

    2017-04-01

    The idea of a hierarchical spatial organization of society lies at the core of seminal theories in human geography that have strongly influenced our understanding of social organization. Along the same line, the recent availability of large-scale human mobility and communication data has offered novel quantitative insights hinting at a strong geographical confinement of human interactions within neighboring regions, extending to local levels within countries. However, models of human interaction largely ignore this effect. Here, we analyze several country-wide networks of telephone calls - both, mobile and landline - and in either case uncover a systematic decrease of communication induced by borders which we identify as the missing variable in state-of-the-art models. Using this empirical evidence, we propose an alternative modeling framework that naturally stylizes the damping effect of borders. We show that this new notion substantially improves the predictive power of widely used interaction models. This increases our ability to understand, model and predict social activities and to plan the development of infrastructures across multiple scales.

  14. Space station crew safety: Human factors interaction model

    NASA Technical Reports Server (NTRS)

    Cohen, M. M.; Junge, M. K.

    1985-01-01

    A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this space station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.

  15. A validation study of a stochastic model of human interaction

    NASA Astrophysics Data System (ADS)

    Burchfield, Mitchel Talmadge

    The purpose of this dissertation is to validate a stochastic model of human interactions which is part of a developmentalism paradigm. Incorporating elements of ancient and contemporary philosophy and science, developmentalism defines human development as a progression of increasing competence and utilizes compatible theories of developmental psychology, cognitive psychology, educational psychology, social psychology, curriculum development, neurology, psychophysics, and physics. To validate a stochastic model of human interactions, the study addressed four research questions: (a) Does attitude vary over time? (b) What are the distributional assumptions underlying attitudes? (c) Does the stochastic model, {-}N{intlimitssbsp{-infty}{infty}}varphi(chi,tau)\\ Psi(tau)dtau, have utility for the study of attitudinal distributions and dynamics? (d) Are the Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein theories applicable to human groups? Approximately 25,000 attitude observations were made using the Semantic Differential Scale. Positions of individuals varied over time and the logistic model predicted observed distributions with correlations between 0.98 and 1.0, with estimated standard errors significantly less than the magnitudes of the parameters. The results bring into question the applicability of Fisherian research designs (Fisher, 1922, 1928, 1938) for behavioral research based on the apparent failure of two fundamental assumptions-the noninteractive nature of the objects being studied and normal distribution of attributes. The findings indicate that individual belief structures are representable in terms of a psychological space which has the same or similar properties as physical space. The psychological space not only has dimension, but individuals interact by force equations similar to those described in theoretical physics models. Nonlinear regression techniques were used to estimate Fermi-Dirac parameters from the data. The model explained a high degree

  16. Rich-and-Poor Model for Human and Nature Interaction

    NASA Astrophysics Data System (ADS)

    Motesharrei, S.; Kalnay, E.; Rivas, J.; Rich-n-Poor

    2011-12-01

    Historical evidence shows collapse of several civilizations in different regions of the world. Jared Diamond presents an account of such societal failures in his 2005 book "Collapse: How Societies Choose to Fail or Succeed." As a precursor to building a complex model for interaction of human and environment, we developed a "thought-experiment" model based on Lotka-Volterra equations for the interaction of two species, known as the Predator-Prey model. We constructed a fairly simple rich-and-poor model that includes only four state variables (or stocks): Rich Population, Poor Population, Nature, and Rich Savings. We observed several scenarios for growth of societies by varying the model's parameter values, including scenarios that resemble the catastrophic fall of ancient civilizations such as the Maya and Anasazi.

  17. Adapting GOMS to Model Human-Robot Interaction

    SciTech Connect

    Drury, Jill; Scholtz, Jean; Kieras, David

    2007-03-09

    Human-robot interaction (HRI) has been maturing in tandem with robots’ commercial success. In the last few years HRI researchers have been adopting—and sometimes adapting—human-computer interaction (HCI) evaluation techniques to assess the efficiency and intuitiveness of HRI designs. For example, Adams (2005) used Goal Directed Task Analysis to determine the interaction needs of officers from the Nashville Metro Police Bomb Squad. Scholtz et al. (2004) used Endsley’s (1988) Situation Awareness Global Assessment Technique to determine robotic vehicle supervisors’ awareness of when vehicles were in trouble and thus required closer monitoring or intervention. Yanco and Drury (2004) employed usability testing to determine (among other things) how well a search-andrescue interface supported use by first responders. One set of HCI tools that has so far seen little exploration in the HRI domain, however, is the class of modeling and evaluation techniques known as formal methods.

  18. Exploring host–microbiota interactions in animal models and humans

    PubMed Central

    Kostic, Aleksandar D.; Howitt, Michael R.; Garrett, Wendy S.

    2013-01-01

    The animal and bacterial kingdoms have coevolved and coadapted in response to environmental selective pressures over hundreds of millions of years. The meta'omics revolution in both sequencing and its analytic pipelines is fostering an explosion of interest in how the gut microbiome impacts physiology and propensity to disease. Gut microbiome studies are inherently interdisciplinary, drawing on approaches and technical skill sets from the biomedical sciences, ecology, and computational biology. Central to unraveling the complex biology of environment, genetics, and microbiome interaction in human health and disease is a deeper understanding of the symbiosis between animals and bacteria. Experimental model systems, including mice, fish, insects, and the Hawaiian bobtail squid, continue to provide critical insight into how host–microbiota homeostasis is constructed and maintained. Here we consider how model systems are influencing current understanding of host–microbiota interactions and explore recent human microbiome studies. PMID:23592793

  19. Head Motion Modeling for Human Behavior Analysis in Dyadic Interaction

    PubMed Central

    Xiao, Bo; Georgiou, Panayiotis; Baucom, Brian; Narayanan, Shrikanth S.

    2015-01-01

    This paper presents a computational study of head motion in human interaction, notably of its role in conveying interlocutors’ behavioral characteristics. Head motion is physically complex and carries rich information; current modeling approaches based on visual signals, however, are still limited in their ability to adequately capture these important properties. Guided by the methodology of kinesics, we propose a data driven approach to identify typical head motion patterns. The approach follows the steps of first segmenting motion events, then parametrically representing the motion by linear predictive features, and finally generalizing the motion types using Gaussian mixture models. The proposed approach is experimentally validated using video recordings of communication sessions from real couples involved in a couples therapy study. In particular we use the head motion model to classify binarized expert judgments of the interactants’ specific behavioral characteristics where entrainment in head motion is hypothesized to play a role: Acceptance, Blame, Positive, and Negative behavior. We achieve accuracies in the range of 60% to 70% for the various experimental settings and conditions. In addition, we describe a measure of motion similarity between the interaction partners based on the proposed model. We show that the relative change of head motion similarity during the interaction significantly correlates with the expert judgments of the interactants’ behavioral characteristics. These findings demonstrate the effectiveness of the proposed head motion model, and underscore the promise of analyzing human behavioral characteristics through signal processing methods. PMID:26557047

  20. Modeling of interactions of electromagnetic fields with human bodies

    NASA Astrophysics Data System (ADS)

    Caputa, Krzysztof

    Interactions of electromagnetic fields with the human body have been a subject of scientific interest and public concern. In recent years, issues in power line field effects and those of wireless telephones have been in the forefront of research. Engineering research compliments biological investigations by quantifying the induced fields in biological bodies due to exposure to external fields. The research presented in this thesis aims at providing reliable tools, and addressing some of the unresolved issues related to interactions with the human body of power line fields and fields produced by handheld wireless telephones. The research comprises two areas, namely development of versatile models of the human body and their visualisation, and verification and application of numerical codes to solve selected problems of interest. The models of the human body, which are based on the magnetic resonance scans of the body, are unique and differ considerably from other models currently available. With the aid of computer software developed, the models can be arranged to different postures, and medical devices can be accurately placed inside them. A previously developed code for modeling interactions of power line fields with biological bodies has been verified by rigorous, quantitative inter-laboratory comparison for two human body models. This code has been employed to model electromagnetic interference (EMI) of the magnetic field with implanted cardiac pacemakers. In this case, the correct placement and representation of the pacemaker leads are critical, as simplified computations have been shown to result in significant errors. In modeling interactions of wireless communication devices, the finite difference time domain technique (FDTD) has become a de facto standard. The previously developed code has been verified by comparison with the analytical solution for a conductive sphere. While previously researchers limited their verifications to principal axes of the sphere

  1. Bayesian Safety Risk Modeling of Human-Flightdeck Automation Interaction

    NASA Technical Reports Server (NTRS)

    Ancel, Ersin; Shih, Ann T.

    2015-01-01

    Usage of automatic systems in airliners has increased fuel efficiency, added extra capabilities, enhanced safety and reliability, as well as provide improved passenger comfort since its introduction in the late 80's. However, original automation benefits, including reduced flight crew workload, human errors or training requirements, were not achieved as originally expected. Instead, automation introduced new failure modes, redistributed, and sometimes increased workload, brought in new cognitive and attention demands, and increased training requirements. Modern airliners have numerous flight modes, providing more flexibility (and inherently more complexity) to the flight crew. However, the price to pay for the increased flexibility is the need for increased mode awareness, as well as the need to supervise, understand, and predict automated system behavior. Also, over-reliance on automation is linked to manual flight skill degradation and complacency in commercial pilots. As a result, recent accidents involving human errors are often caused by the interactions between humans and the automated systems (e.g., the breakdown in man-machine coordination), deteriorated manual flying skills, and/or loss of situational awareness due to heavy dependence on automated systems. This paper describes the development of the increased complexity and reliance on automation baseline model, named FLAP for FLightdeck Automation Problems. The model development process starts with a comprehensive literature review followed by the construction of a framework comprised of high-level causal factors leading to an automation-related flight anomaly. The framework was then converted into a Bayesian Belief Network (BBN) using the Hugin Software v7.8. The effects of automation on flight crew are incorporated into the model, including flight skill degradation, increased cognitive demand and training requirements along with their interactions. Besides flight crew deficiencies, automation system

  2. Agent Based Modeling of Human Gut Microbiome Interactions and Perturbations

    PubMed Central

    Shashkova, Tatiana; Popenko, Anna; Tyakht, Alexander; Peskov, Kirill; Kosinsky, Yuri; Bogolubsky, Lev; Raigorodskii, Andrei; Ischenko, Dmitry; Alexeev, Dmitry; Govorun, Vadim

    2016-01-01

    Background Intestinal microbiota plays an important role in the human health. It is involved in the digestion and protects the host against external pathogens. Examination of the intestinal microbiome interactions is required for understanding of the community influence on host health. Studies of the microbiome can provide insight on methods of improving health, including specific clinical procedures for individual microbial community composition modification and microbiota correction by colonizing with new bacterial species or dietary changes. Methodology/Principal Findings In this work we report an agent-based model of interactions between two bacterial species and between species and the gut. The model is based on reactions describing bacterial fermentation of polysaccharides to acetate and propionate and fermentation of acetate to butyrate. Antibiotic treatment was chosen as disturbance factor and used to investigate stability of the system. System recovery after antibiotic treatment was analyzed as dependence on quantity of feedback interactions inside the community, therapy duration and amount of antibiotics. Bacterial species are known to mutate and acquire resistance to the antibiotics. The ability to mutate was considered to be a stochastic process, under this suggestion ratio of sensitive to resistant bacteria was calculated during antibiotic therapy and recovery. Conclusion/Significance The model confirms a hypothesis of feedbacks mechanisms necessity for providing functionality and stability of the system after disturbance. High fraction of bacterial community was shown to mutate during antibiotic treatment, though sensitive strains could become dominating after recovery. The recovery of sensitive strains is explained by fitness cost of the resistance. The model demonstrates not only quantitative dynamics of bacterial species, but also gives an ability to observe the emergent spatial structure and its alteration, depending on various feedback mechanisms

  3. Generating Phenotypical Erroneous Human Behavior to Evaluate Human-automation Interaction Using Model Checking

    PubMed Central

    Bolton, Matthew L.; Bass, Ellen J.; Siminiceanu, Radu I.

    2012-01-01

    Breakdowns in complex systems often occur as a result of system elements interacting in unanticipated ways. In systems with human operators, human-automation interaction associated with both normative and erroneous human behavior can contribute to such failures. Model-driven design and analysis techniques provide engineers with formal methods tools and techniques capable of evaluating how human behavior can contribute to system failures. This paper presents a novel method for automatically generating task analytic models encompassing both normative and erroneous human behavior from normative task models. The generated erroneous behavior is capable of replicating Hollnagel’s zero-order phenotypes of erroneous action for omissions, jumps, repetitions, and intrusions. Multiple phenotypical acts can occur in sequence, thus allowing for the generation of higher order phenotypes. The task behavior model pattern capable of generating erroneous behavior can be integrated into a formal system model so that system safety properties can be formally verified with a model checker. This allows analysts to prove that a human-automation interactive system (as represented by the model) will or will not satisfy safety properties with both normative and generated erroneous human behavior. We present benchmarks related to the size of the statespace and verification time of models to show how the erroneous human behavior generation process scales. We demonstrate the method with a case study: the operation of a radiation therapy machine. A potential problem resulting from a generated erroneous human action is discovered. A design intervention is presented which prevents this problem from occurring. We discuss how our method could be used to evaluate larger applications and recommend future paths of development. PMID:23105914

  4. Spoken language interaction with model uncertainty: an adaptive human-robot interaction system

    NASA Astrophysics Data System (ADS)

    Doshi, Finale; Roy, Nicholas

    2008-12-01

    Spoken language is one of the most intuitive forms of interaction between humans and agents. Unfortunately, agents that interact with people using natural language often experience communication errors and do not correctly understand the user's intentions. Recent systems have successfully used probabilistic models of speech, language and user behaviour to generate robust dialogue performance in the presence of noisy speech recognition and ambiguous language choices, but decisions made using these probabilistic models are still prone to errors owing to the complexity of acquiring and maintaining a complete model of human language and behaviour. In this paper, a decision-theoretic model for human-robot interaction using natural language is described. The algorithm is based on the Partially Observable Markov Decision Process (POMDP), which allows agents to choose actions that are robust not only to uncertainty from noisy or ambiguous speech recognition but also unknown user models. Like most dialogue systems, a POMDP is defined by a large number of parameters that may be difficult to specify a priori from domain knowledge, and learning these parameters from the user may require an unacceptably long training period. An extension to the POMDP model is described that allows the agent to acquire a linguistic model of the user online, including new vocabulary and word choice preferences. The approach not only avoids a training period of constant questioning as the agent learns, but also allows the agent actively to query for additional information when its uncertainty suggests a high risk of mistakes. The approach is demonstrated both in simulation and on a natural language interaction system for a robotic wheelchair application.

  5. Human-machine interactions

    DOEpatents

    Forsythe, J. Chris; Xavier, Patrick G.; Abbott, Robert G.; Brannon, Nathan G.; Bernard, Michael L.; Speed, Ann E.

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  6. A Framework for Modeling Human-Machine Interactions

    NASA Technical Reports Server (NTRS)

    Shafto, Michael G.; Rosekind, Mark R. (Technical Monitor)

    1996-01-01

    Modern automated flight-control systems employ a variety of different behaviors, or modes, for managing the flight. While developments in cockpit automation have resulted in workload reduction and economical advantages, they have also given rise to an ill-defined class of human-machine problems, sometimes referred to as 'automation surprises'. Our interest in applying formal methods for describing human-computer interaction stems from our ongoing research on cockpit automation. In this area of aeronautical human factors, there is much concern about how flight crews interact with automated flight-control systems, so that the likelihood of making errors, in particular mode-errors, is minimized and the consequences of such errors are contained. The goal of the ongoing research on formal methods in this context is: (1) to develop a framework for describing human interaction with control systems; (2) to formally categorize such automation surprises; and (3) to develop tests for identification of these categories early in the specification phase of a new human-machine system.

  7. A Framework for Modeling Human-Machine Interactions

    NASA Technical Reports Server (NTRS)

    Shafto, Michael G.; Rosekind, Mark R. (Technical Monitor)

    1996-01-01

    Modern automated flight-control systems employ a variety of different behaviors, or modes, for managing the flight. While developments in cockpit automation have resulted in workload reduction and economical advantages, they have also given rise to an ill-defined class of human-machine problems, sometimes referred to as 'automation surprises'. Our interest in applying formal methods for describing human-computer interaction stems from our ongoing research on cockpit automation. In this area of aeronautical human factors, there is much concern about how flight crews interact with automated flight-control systems, so that the likelihood of making errors, in particular mode-errors, is minimized and the consequences of such errors are contained. The goal of the ongoing research on formal methods in this context is: (1) to develop a framework for describing human interaction with control systems; (2) to formally categorize such automation surprises; and (3) to develop tests for identification of these categories early in the specification phase of a new human-machine system.

  8. Humans in Biogeophysical Models: Colonial Period Human-Environment Interactions in the Northeastern United States

    NASA Astrophysics Data System (ADS)

    Parolari, A.; Greco, F.; Green, M.; Lally, M.; Hermans, C.

    2008-12-01

    Earth system models increasingly require representation of human activities and the important role they play in the environment. At the most fundamental level, human decisions are driven by the need to acquire basic resources - nutrients, energy, water, and space - each derived from the biogeophysical setting. Modern theories in Ecological Economics place these basic resources at the base of a consumption hierarchy (from subsistence to luxury resources) on which societies and economies are built. Human decisions at all levels of this hierarchy are driven by dynamic environmental, social, and economic factors. Therefore, models merging socio-economic and biogeophysical dynamics are required to predict the evolving relationship between humans and the hydrologic cycle. To provide an example, our study focuses on changes to the hydrologic cycle during the United States colonial period (1600 to 1800). Both direct, intentional, human water use (e.g. water supply, irrigation, or hydropower) and indirect, unintentional effects resulting from the use of other resources (e.g. deforestation or beaver trapping) are considered. We argue that water was not the limiting resource to either the Native or Colonist population growth. However, food and tobacco production and harvesting of beaver pelts led to indirect interventions and consequent changes in the hydrologic cycle. The analysis presented here suggests the importance of incorporating human decision- making dynamics with existing geophysical models to fully understand trajectories of human-environment interactions. Predictive tools of this type are critical to characterizing the long-term signature of humans on the landscape and hydrologic cycle.

  9. Modeling human diseases: an education in interactions and interdisciplinary approaches

    PubMed Central

    2016-01-01

    ABSTRACT Traditionally, most investigators in the biomedical arena exploit one model system in the course of their careers. Occasionally, an investigator will switch models. The selection of a suitable model system is a crucial step in research design. Factors to consider include the accuracy of the model as a reflection of the human disease under investigation, the numbers of animals needed and ease of husbandry, its physiology and developmental biology, and the ability to apply genetics and harness the model for drug discovery. In my lab, we have primarily used the zebrafish but combined it with other animal models and provided a framework for others to consider the application of developmental biology for therapeutic discovery. Our interdisciplinary approach has led to many insights into human diseases and to the advancement of candidate drugs to clinical trials. Here, I draw on my experiences to highlight the importance of combining multiple models, establishing infrastructure and genetic tools, forming collaborations, and interfacing with the medical community for successful translation of basic findings to the clinic. PMID:27483497

  10. Flow-structure-acoustic interaction in a human voice model.

    PubMed

    Becker, Stefan; Kniesburges, Stefan; Müller, Stefan; Delgado, Antonio; Link, Gerhard; Kaltenbacher, Manfred; Döllinger, Michael

    2009-03-01

    For the investigation of the physical processes of human phonation, inhomogeneous synthetic vocal folds were developed to represent the full fluid-structure-acoustic coupling. They consisted of polyurethane rubber with a stiffness in the range of human vocal folds and were mounted in a channel, shaped like the vocal tract in the supraglottal region. This test facility permitted extensive observations of flow-induced vocal fold vibrations, the periodic flow field, and the acoustic signals in the far field of the channel. Detailed measurements were performed applying particle-image velocimetry, a laser-scanning vibrometer, a microphone, unsteady pressure sensors, and a hot-wire probe, with the aim of identifying the physical mechanisms in human phonation. The results support the existence of the Coanda effect during phonation, with the flow attaching to one vocal fold and separating from the other. This behavior is not linked to one vocal fold and changes stochastically from cycle to cycle. The oscillating flow field generates a tonal sound. The broadband noise is presumed to be caused by the interaction of the asymmetric flow with the downstream-facing surfaces of the vocal folds, analogous to trailing-edge noise.

  11. Modeling human-flood interactions: Collective action and community resilience.

    NASA Astrophysics Data System (ADS)

    Yu, D. J.; Sangwan, N.; Sung, K.

    2016-12-01

    Stylized models of socio-hydrology have mainly used social memory aspects such as community awareness or sensitivity to connect hydrologic change and social response. However, social memory alone does not satisfactorily capture the details of how human behavior is translated into collective action for water resources governance. Nor is it the only mechanism by which the two-way feedbacks of socio-hydrology can be operationalized. This study contributes towards bridging of this gap by developing a stylized model of a human-flood system that includes two additional drivers of change: (1) institutions for collective action, and (2) connections to an external economic system. Motivated by the case of community-managed flood protection systems (polders) in coastal Bangladesh, we use the model to understand critical general features that affect long-term resilience of human-flood systems. Our findings suggest that occasional adversity can enhance long-term resilience. Allowing some hydrological variability to enter into the polder can increase its adaptive capacity and resilience through the preservation of social memory and institutions for collective action. Further, there are potential tradeoffs associated with optimization of flood resilience through structural measures. By reducing sensitivity to flooding, the system may become more fragile under the double impact of flooding and economic change

  12. Carbon-climate-human interactions in an integrated human-Earth system model

    NASA Astrophysics Data System (ADS)

    Calvin, K. V.; Bond-Lamberty, B. P.; Jones, A. D.; Shi, X.

    2016-12-01

    The C4MIP and CMIP5 results highlighted large uncertainties in climate projections, driven to a large extent by limited understanding of the interactions between terrestrial carbon-cycle and climate feedbacks, and their associated uncertainties. These feedbacks are dominated by uncertainties in soil processes, disturbance dynamics, ecosystem response to climate change, and agricultural productivity, and land-use change. This research addresses three questions: (1) how do terrestrial feedbacks vary across different levels of climate change, (2) what is the relative contribution of CO2 fertilization and climate change, and (3) how robust are the results across different models and methods? We used a coupled modeling framework that integrates an Integrated Assessment Model (modeling economic and energy activity) with an Earth System Model (modeling the natural earth system) to examine how business-as-usual (RCP 8.5) climate change will affect ecosystem productivity, cropland extent, and other aspects of the human-Earth system. We find that higher levels of radiative forcing result in higher productivity growth, that increases in CO2 concentrations are the dominant contributors to that growth, and that our productivity increases fall in the middle of the range when compared to other CMIP5 models and the AgMIP models. These results emphasize the importance of examining both the anthropogenic and natural components of the earth system, and their long-term interactive feedbacks.

  13. A Simple Model for Human and Nature Interaction

    NASA Astrophysics Data System (ADS)

    Motesharrei, S.; Rivas, J.; Kalnay, E.

    2012-12-01

    There are widespread concerns that current trends in population and resource-use are unsustainable, but the possibilities of an overshoot and collapse remain unclear and controversial. Collapses of civilizations have occurred many times in the past 5000 years, often followed by centuries of economic, intellectual, and population decline. Many different natural and social phenomena have been invoked to explain specific collapses, but a general explanation remains elusive. Two important features seem to appear across societies that have collapsed: Ecological Strain and Economic Stratification. Our new model (Human And Nature DYnamics, HANDY) has just four equations that describe the evolution of Elites, Commoners, Nature, and Wealth. Mechanisms leading to collapse are discussed and the measure "Carrying Capacity" is developed and defined. The model shows that societal collapse can happen due to either one of two independent factors: (1) over-consumption of natural resources, and/or (2) deep inequity between Elites and Commoners. The model also portrays two distinct types of collapse: (i) collapse followed by recovery of nature, and (ii) full collapse. The model suggests that the estimation of Carrying Capacity is a practical means for early detection of a collapse. Collapse can be avoided, and population can reach a sustainable equilibrium, if the rate of depletion of nature is reduced to a sustainable level, and if resources are distributed in a reasonably equitable fashion.; A type-ii (full) collapse is shown in this figure. With high inequality and high depletion, societies are doomed to collapse. Wealth starts to decrease when population rises above the carrying capacity. The large gap between carrying capacity and its maximum is a result of depletion factor being much larger than the sustainable limit. ; It is possible to overshoot, oscillate, and eventually converge to an equilibrium, even in an inequitable society. However, it requires policies that control

  14. [An interactive three-dimensional model of the human body].

    PubMed

    Liem, S L

    2009-01-01

    Driven by advanced computer technology, it is now possible to show the human anatomy on a computer. On the internet, the Visible Body programme makes it possible to navigate in all directions through the anatomical structures of the human body, using mouse and keyboard. Visible Body is a wonderful tool to give insight in the human structures, body functions and organs.

  15. Holistic Modeling for Human-Autonomous System Interaction

    DTIC Science & Technology

    2015-01-01

    primary mission for all vehicles is surveillance with the ultimate goal of locating specific objects of interest in urban coastal and inland settings...complex systems. Discrete event simulation (DES) models and system dynamics (SD) models are two different approaches that can be used to address these...better suited for modeling continuous performance feedback that is temporally dependent and is affected by qualitative variables such as trust. 15

  16. Modeling the performance of the human (pilot) interaction in a synthetic flight domain: Information theoretic approach

    NASA Technical Reports Server (NTRS)

    Ntuen, Celestine A.

    1992-01-01

    Current advances in computing technology are devoid of formal methods that describe the theories of how information is shared between humans and machines. Specifically, in the domain of human-machine interaction, a common mathematical foundation is lacking. The aim of this paper is to propose a formal method of human-machine (H-M) interaction paradigm from the information view point. The methods presented are interpretation- and context-free and can be used both in experimental analysis as well as in modeling problems.

  17. Human-telerobot interactions - Information, control, and mental models

    NASA Technical Reports Server (NTRS)

    Smith, Randy L.; Gillan, Douglas J.

    1987-01-01

    A part of the NASA's Space Station will be a teleoperated robot (telerobot) with arms for grasping and manipulation, feet for holding onto objects, and television cameras for visual feedback. The objective of the work described in this paper is to develop the requirements and specifications for the user-telerobot interface and to determine through research and testing that the interface results in efficient system operation. The focus of the development of the user-telerobot interface is on the information required by the user, the user inputs, and the design of the control workstation. Closely related to both the information required by the user and the user's control of the telerobot is the user's mental model of the relationship between the control inputs and the telerobot's actions.

  18. Expert-system usability: Modeling and analysis of human-advisor interaction

    SciTech Connect

    Mitta, D.A.

    1988-01-01

    Usability of an expert system is dependent upon the relationship between a human user and the expert-system interface. The interface is defined as any combination of equipment with which the user and expert system communicate. Within the context of this research, the interface is considered to be the expert system text and graphics appearing on display hardware. This type of interface is known as an advisor. A state transition model is used to represent human-advisor interaction. The model provides a mechanism by which to collect objective human performance data. In addition, it is used to specify human-advisor interaction metrics. To test the state transition model, an expert system, Function Diagnostic, was developed. Function Diagnostic determines mathematical expressions for the graphical representation of selected piecewise linear and polynomial function. An experiment was performed in which subjects used Function Diagnostic to solve problems. Each problem was associated with one of three levels of difficulty: easy, moderate, and hard.

  19. Elucidating the interactions between the human gut microbiota and its host through metabolic modeling.

    PubMed

    Shoaie, Saeed; Nielsen, Jens

    2014-01-01

    Increased understanding of the interactions between the gut microbiota, diet and environmental effects may allow us to design efficient treatment strategies for addressing global health problems. Existence of symbiotic microorganisms in the human gut provides different functions for the host such as conversion of nutrients, training of the immune system, and resistance to pathogens. The gut microbiome also plays an influential role in maintaining human health, and it is a potential target for prevention and treatment of common disorders including obesity, type 2 diabetes, and atherosclerosis. Due to the extreme complexity of such disorders, it is necessary to develop mathematical models for deciphering the role of its individual elements as well as the entire system and such models may assist in better understanding of the interactions between the bacteria in the human gut and the host by use of genome-scale metabolic models (GEMs). Recently, GEMs have been employed to explore the interactions between predominant bacteria in the gut ecosystems. Additionally, these models enabled analysis of the contribution of each species to the overall metabolism of the microbiota through the integration of omics data. The outcome of these studies can be used for proposing optimal conditions for desired microbiome phenotypes. Here, we review the recent progress and challenges for elucidating the interactions between the human gut microbiota and host through metabolic modeling. We discuss how these models may provide scaffolds for analyzing high-throughput data, developing probiotics and prebiotics, evaluating the effects of probiotics and prebiotics and eventually designing clinical interventions.

  20. Large-scale in silico modeling of metabolic interactions between cell types in the human brain.

    PubMed

    Lewis, Nathan E; Schramm, Gunnar; Bordbar, Aarash; Schellenberger, Jan; Andersen, Michael P; Cheng, Jeffrey K; Patel, Nilam; Yee, Alex; Lewis, Randall A; Eils, Roland; König, Rainer; Palsson, Bernhard Ø

    2010-12-01

    Metabolic interactions between multiple cell types are difficult to model using existing approaches. Here we present a workflow that integrates gene expression data, proteomics data and literature-based manual curation to model human metabolism within and between different types of cells. Transport reactions are used to account for the transfer of metabolites between models of different cell types via the interstitial fluid. We apply the method to create models of brain energy metabolism that recapitulate metabolic interactions between astrocytes and various neuron types relevant to Alzheimer's disease. Analysis of the models identifies genes and pathways that may explain observed experimental phenomena, including the differential effects of the disease on cell types and regions of the brain. Constraint-based modeling can thus contribute to the study and analysis of multicellular metabolic processes in the human tissue microenvironment and provide detailed mechanistic insight into high-throughput data analysis.

  1. Integrated interactions database: tissue-specific view of the human and model organism interactomes.

    PubMed

    Kotlyar, Max; Pastrello, Chiara; Sheahan, Nicholas; Jurisica, Igor

    2016-01-04

    IID (Integrated Interactions Database) is the first database providing tissue-specific protein-protein interactions (PPIs) for model organisms and human. IID covers six species (S. cerevisiae (yeast), C. elegans (worm), D. melonogaster (fly), R. norvegicus (rat), M. musculus (mouse) and H. sapiens (human)) and up to 30 tissues per species. Users query IID by providing a set of proteins or PPIs from any of these organisms, and specifying species and tissues where IID should search for interactions. If query proteins are not from the selected species, IID enables searches across species and tissues automatically by using their orthologs; for example, retrieving interactions in a given tissue, conserved in human and mouse. Interaction data in IID comprises three types of PPI networks: experimentally detected PPIs from major databases, orthologous PPIs and high-confidence computationally predicted PPIs. Interactions are assigned to tissues where their proteins pairs or encoding genes are expressed. IID is a major replacement of the I2D interaction database, with larger PPI networks (a total of 1,566,043 PPIs among 68,831 proteins), tissue annotations for interactions, and new query, analysis and data visualization capabilities. IID is available at http://ophid.utoronto.ca/iid.

  2. Human-pet interaction and loneliness: a test of concepts from Roy's adaptation model.

    PubMed

    Calvert, M M

    1989-01-01

    This research used two key concepts from Roy's adaptation model of nursing to examine the relationship between human-pet interaction and loneliness in nursing home residents. These concepts included (a) environmental stimuli as factors influencing adaptation and (b) interdependence as a mode of response to the environment. The hypothesis of this study asserted that the residents of a nursing home who had greater levels of interaction with a pet program would experience less loneliness than those who had lower levels of interaction with a pet. The study used an ex post facto nonexperimental design with 65 subjects. The simplified version of the revised UCLA loneliness scale was used to measure loneliness. Reported level of human-pet interaction was measured according to a four-point scale (1 = no interaction, 4 = quite a lot of interaction). The hypothesis was supported at the p less than 0.03 level of significance. Implications for practice through organizing pet programs in situations where loneliness exists are discussed. Recommendations for future research include replicating the study using a larger sample and developing a comprehensive human-pet interaction tool.

  3. Modeling 4D Human-Object Interactions for Joint Event Segmentation, Recognition, and Object Localization.

    PubMed

    Wei, Ping; Zhao, Yibiao; Zheng, Nanning; Zhu, Song-Chun

    2016-06-01

    In this paper, we present a 4D human-object interaction (4DHOI) model for solving three vision tasks jointly: i) event segmentation from a video sequence, ii) event recognition and parsing, and iii) contextual object localization. The 4DHOI model represents the geometric, temporal, and semantic relations in daily events involving human-object interactions. In 3D space, the interactions of human poses and contextual objects are modeled by semantic co-occurrence and geometric compatibility. On the time axis, the interactions are represented as a sequence of atomic event transitions with coherent objects. The 4DHOI model is a hierarchical spatial-temporal graph representation which can be used for inferring scene functionality and object affordance. The graph structures and parameters are learned using an ordered expectation maximization algorithm which mines the spatial-temporal structures of events from RGB-D video samples. Given an input RGB-D video, the inference is performed by a dynamic programming beam search algorithm which simultaneously carries out event segmentation, recognition, and object localization. We collected and released a large multiview RGB-D event dataset which contains 3,815 video sequences and 383,036 RGB-D frames captured by three RGB-D cameras. The experimental results on three challenging datasets demonstrate the strength of the proposed method.

  4. Investigation of the interaction between five alkaloids and human hemoglobin by fluorescence spectroscopy and molecular modeling.

    PubMed

    He, Wu; Dou, Huanjing; Li, Zhigang; Wang, Xiaogai; Wang, Lvjing; Wang, Ruiyong; Chang, Junbiao

    2014-04-05

    This work studied the interaction of human hemoglobin (HHb) with aminophylline, acefylline, caffeine, theophylline and diprophylline systematically by UV-vis absorption spectroscopy and fluorescence spectroscopy in combination with molecular modeling. Five alkaloids caused the fluorescence quenching of HHb by the formation of alkaloids-HHb complex. The binding constants and thermodynamic parameters were obtained. The hydrophobic and electrostatic interactions were the predominant intermolecular forces to stabilize these complexes. Results of thermodynamic analysis and molecular modeling showed that aminophylline was the strongest quencher and diprophylline was the weakest quencher.

  5. Toward a 3D model of human brain development for studying gene/environment interactions.

    PubMed

    Hogberg, Helena T; Bressler, Joseph; Christian, Kimberly M; Harris, Georgina; Makri, Georgia; O'Driscoll, Cliona; Pamies, David; Smirnova, Lena; Wen, Zhexing; Hartung, Thomas

    2013-01-01

    This project aims to establish and characterize an in vitro model of the developing human brain for the purpose of testing drugs and chemicals. To accurately assess risk, a model needs to recapitulate the complex interactions between different types of glial cells and neurons in a three-dimensional platform. Moreover, human cells are preferred over cells from rodents to eliminate cross-species differences in sensitivity to chemicals. Previously, we established conditions to culture rat primary cells as three-dimensional aggregates, which will be humanized and evaluated here with induced pluripotent stem cells (iPSCs). The use of iPSCs allows us to address gene/environment interactions as well as the potential of chemicals to interfere with epigenetic mechanisms. Additionally, iPSCs afford us the opportunity to study the effect of chemicals during very early stages of brain development. It is well recognized that assays for testing toxicity in the developing brain must consider differences in sensitivity and susceptibility that arise depending on the time of exposure. This model will reflect critical developmental processes such as proliferation, differentiation, lineage specification, migration, axonal growth, dendritic arborization and synaptogenesis, which will probably display differences in sensitivity to different types of chemicals. Functional endpoints will evaluate the complex cell-to-cell interactions that are affected in neurodevelopment through chemical perturbation, and the efficacy of drug intervention to prevent or reverse phenotypes. The model described is designed to assess developmental neurotoxicity effects on unique processes occurring during human brain development by leveraging human iPSCs from diverse genetic backgrounds, which can be differentiated into different cell types of the central nervous system. Our goal is to demonstrate the feasibility of the personalized model using iPSCs derived from individuals with neurodevelopmental disorders

  6. Interactive locomotion: Investigation and modeling of physically-paired humans while walking

    PubMed Central

    Le Goff, Camille G.; Ijspeert, Auke Jan

    2017-01-01

    In spite of extensive studies on human walking, less research has been conducted on human walking gait adaptation during interaction with another human. In this paper, we study a particular case of interactive locomotion where two humans carry a rigid object together. Experimental data from two persons walking together, one in front of the other, while carrying a stretcher-like object is presented, and the adaptation of their walking gaits and coordination of the foot-fall patterns are analyzed. It is observed that in more than 70% of the experiments the subjects synchronize their walking gaits; it is shown that these walking gaits can be associated to quadrupedal gaits. Moreover, in order to understand the extent by which the passive dynamics can explain this synchronization behaviour, a simple 2D model, made of two-coupled spring-loaded inverted pendulums, is developed, and a comparison between the experiments and simulations with this model is presented, showing that with this simple model we are able to reproduce some aspects of human walking behaviour when paired with another human. PMID:28877161

  7. Formulation of human-structure interaction system models for vertical vibration

    NASA Astrophysics Data System (ADS)

    Caprani, Colin C.; Ahmadi, Ehsan

    2016-09-01

    In this paper, human-structure interaction system models for vibration in the vertical direction are considered. This work assembles various moving load models from the literature and proposes extension of the single pedestrian to a crowd of pedestrians for the FE formulation for crowd-structure interaction systems. The walking pedestrian vertical force is represented as a general time-dependent force, and the pedestrian is in turn modelled as moving force, moving mass, and moving spring-mass-damper. The arbitrary beam structure is modelled using either a formulation in modal coordinates or finite elements. In each case, the human-structure interaction (HSI) system is first formulated for a single walking pedestrian and then extended to consider a crowd of pedestrians. Finally, example applications for single pedestrian and crowd loading scenarios are examined. It is shown how the models can be used to quantify the interaction between the crowd and bridge structure. This work should find use for the evaluation of existing and new footbridges.

  8. Effects of molecular model, ionic strength, divalent ions, and hydrophobic interaction on human neurofilament conformation.

    PubMed

    Lee, Joonseong; Kim, Seonghoon; Chang, Rakwoo; Jayanthi, Lakshmi; Gebremichael, Yeshitila

    2013-01-07

    The present study examines the effects of the model dependence, ionic strength, divalent ions, and hydrophobic interaction on the structural organization of the human neurofilament (NF) brush, using canonical ensemble Monte Carlo (MC) simulations of a coarse-grained model with the amino-acid resolution. The model simplifies the interactions between the NF core and the sidearm or between the sidearms by the sum of excluded volume, electrostatic, and hydrophobic interactions, where both monovalent salt ions and solvents are implicitly incorporated into the electrostatic interaction potential. Several important observations are made from the MC simulations of the coarse-grained model NF systems. First, the mean-field type description of monovalent salt ions works reasonably well in the NF system. Second, the manner by which the NF sidearms are arranged on the surface of the NF backbone core has little influence on the lateral extension of NF sidearms. Third, the lateral extension of the NF sidearms is highly affected by the ionic strength of the system: at low ionic strength, NF-M is most extended but at high ionic strength, NF-H is more stretched out because of the effective screening of the electrostatic interaction. Fourth, the presence of Ca(2+) ions induces the attraction between negatively charged residues, which leads to the contraction of the overall NF extension. Finally, the introduction of hydrophobic interaction does not change the general structural organization of the NF sidearms except that the overall extension is contracted.

  9. A system dynamics model of human-water interaction in anthropogenic droughts

    NASA Astrophysics Data System (ADS)

    Blair, Peter; Buytaert, Wouter

    2016-04-01

    Modelling is set to be a key part of socio-hydrology's quest to understand the dynamics and long-term consequences of human-water interactions. As a subject in its infancy, still learning the questions to ask, conceptual models are of particular use in trying to understand the general nature of human-water systems. The conceptual model of Di Baldassarre et al. (2013), which investigates human-flood interactions, has been widely discussed, prompting great steps forward in understanding and coverage of socio-hydrology. The development of further conceptual models could generate further discussion and understanding. Flooding is one archetypal example of a system of human-water interaction; another is the case of water stress and drought. There has been a call to recognise and understand anthropogenic drought (Aghakouchak et al. 2015), and so this study investigates the nature of the socio-hydrological dynamics involved in these situations. Here we present a system dynamics model to simulate human-water interactions in the context of water-stressed areas, where drought is induced via a combination of lower than usual water availability and relatively high water use. It is designed based on an analysis of several case-studies where recent droughts have occurred, or where the prospect of drought looms. The locations investigated are Spain, Southeast Brazil, Northeast China and California. The numerical system dynamics model is based on causal loop, and stocks and flows diagrams, which are in turn developed from the qualitative analysis of the different cases studied. The study uses a comparative approach, which has the advantage of eliciting general system characteristics from the similarities between cases, while using the differences to determine the important factors which lead to different system behaviours. References: Aghakouchak, A., Feldman, D., Hoerling, M., Huxman, T., Lund, J., 2015. Recognize anthropogenic drought. Nature, 524, pp.409-411. Di Baldassarre, G

  10. Modeling and Simulation for Exploring Human-Robot Team Interaction Requirements

    SciTech Connect

    Dudenhoeffer, Donald Dean; Bruemmer, David Jonathon; Davis, Midge Lee

    2001-12-01

    Small-sized and micro-robots will soon be available for deployment in large-scale forces. Consequently, the ability of a human operator to coordinate and interact with largescale robotic forces is of great interest. This paper describes the ways in which modeling and simulation have been used to explore new possibilities for human-robot interaction. The paper also discusses how these explorations have fed implementation of a unified set of command and control concepts for robotic force deployment. Modeling and simulation can play a major role in fielding robot teams in actual missions. While live testing is preferred, limitations in terms of technology, cost, and time often prohibit extensive experimentation with physical multi-robot systems. Simulation provides insight, focuses efforts, eliminates large areas of the possible solution space, and increases the quality of actual testing.

  11. Aviation Safety: Modeling and Analyzing Complex Interactions between Humans and Automated Systems

    NASA Technical Reports Server (NTRS)

    Rungta, Neha; Brat, Guillaume; Clancey, William J.; Linde, Charlotte; Raimondi, Franco; Seah, Chin; Shafto, Michael

    2013-01-01

    The on-going transformation from the current US Air Traffic System (ATS) to the Next Generation Air Traffic System (NextGen) will force the introduction of new automated systems and most likely will cause automation to migrate from ground to air. This will yield new function allocations between humans and automation and therefore change the roles and responsibilities in the ATS. Yet, safety in NextGen is required to be at least as good as in the current system. We therefore need techniques to evaluate the safety of the interactions between humans and automation. We think that current human factor studies and simulation-based techniques will fall short in front of the ATS complexity, and that we need to add more automated techniques to simulations, such as model checking, which offers exhaustive coverage of the non-deterministic behaviors in nominal and off-nominal scenarios. In this work, we present a verification approach based both on simulations and on model checking for evaluating the roles and responsibilities of humans and automation. Models are created using Brahms (a multi-agent framework) and we show that the traditional Brahms simulations can be integrated with automated exploration techniques based on model checking, thus offering a complete exploration of the behavioral space of the scenario. Our formal analysis supports the notion of beliefs and probabilities to reason about human behavior. We demonstrate the technique with the Ueberligen accident since it exemplifies authority problems when receiving conflicting advices from human and automated systems.

  12. Model-based safety analysis of human-robot interactions: the MIRAS walking assistance robot.

    PubMed

    Guiochet, Jérémie; Hoang, Quynh Anh Do; Kaaniche, Mohamed; Powell, David

    2013-06-01

    Robotic systems have to cope with various execution environments while guaranteeing safety, and in particular when they interact with humans during rehabilitation tasks. These systems are often critical since their failure can lead to human injury or even death. However, such systems are difficult to validate due to their high complexity and the fact that they operate within complex, variable and uncertain environments (including users), in which it is difficult to foresee all possible system behaviors. Because of the complexity of human-robot interactions, rigorous and systematic approaches are needed to assist the developers in the identification of significant threats and the implementation of efficient protection mechanisms, and in the elaboration of a sound argumentation to justify the level of safety that can be achieved by the system. For threat identification, we propose a method called HAZOP-UML based on a risk analysis technique adapted to system description models, focusing on human-robot interaction models. The output of this step is then injected in a structured safety argumentation using the GSN graphical notation. Those approaches have been successfully applied to the development of a walking assistant robot which is now in clinical validation.

  13. The ‘hit’ phenomenon: a mathematical model of human dynamics interactions as a stochastic process

    NASA Astrophysics Data System (ADS)

    Ishii, Akira; Arakaki, Hisashi; Matsuda, Naoya; Umemura, Sanae; Urushidani, Tamiko; Yamagata, Naoya; Yoshida, Narihiko

    2012-06-01

    A mathematical model for the ‘hit’ phenomenon in entertainment within a society is presented as a stochastic process of human dynamics interactions. The model uses only the advertisement budget time distribution as an input, and word-of-mouth (WOM), represented by posts on social network systems, is used as data to make a comparison with the calculated results. The unit of time is days. The WOM distribution in time is found to be very close to the revenue distribution in time. Calculations for the Japanese motion picture market based on the mathematical model agree well with the actual revenue distribution in time.

  14. Multiscale Modeling of Human-Water Interactions: The Role of Time-Scales

    NASA Astrophysics Data System (ADS)

    Bloeschl, G.; Sivapalan, M.

    2015-12-01

    Much of the interest in hydrological modeling in the past decades revolved around resolving spatial variability. With the rapid changes brought about by human impacts on the hydrologic cycle, there is now an increasing need to refocus on time dependency. We present a co-evolutionary view of hydrologic systems, in which every part of the system including human systems, co-evolve, albeit at different rates. The resulting coupled human-nature system is framed as a dynamical system, characterized by interactions of fast and slow time scales and feedbacks between environmental and social processes. This gives rise to emergent phenomena such as the levee effect, adaptation to change and system collapse due to resource depletion. Changing human values play a key role in the emergence of these phenomena and should therefore be considered as internal to the system in a dynamic way. The co-evolutionary approach differs from the traditional view of water resource systems analysis as it allows for path dependence, multiple equilibria, lock-in situations and emergent phenomena. The approach may assist strategic water management for long time scales through facilitating stakeholder participation, exploring the possibility space of alternative futures, and helping to synthesise the observed dynamics of different case studies. Future research opportunities include the study of how changes in human values are connected to human-water interactions, historical analyses of trajectories of system co-evolution in individual places and comparative analyses of contrasting human-water systems in different climate and socio-economic settings. Reference Sivapalan, M. and G. Blöschl (2015) Time Scale Interactions and the Co-evolution of Humans and Water. Water Resour. Res., 51, in press.

  15. New tools for linking human and earth system models: The Toolbox for Human-Earth System Interaction & Scaling (THESIS)

    NASA Astrophysics Data System (ADS)

    O'Neill, B. C.; Kauffman, B.; Lawrence, P.

    2016-12-01

    Integrated analysis of questions regarding land, water, and energy resources often requires integration of models of different types. One type of integration is between human and earth system models, since both societal and physical processes influence these resources. For example, human processes such as changes in population, economic conditions, and policies govern the demand for land, water and energy, while the interactions of these resources with physical systems determine their availability and environmental consequences. We have begun to develop and use a toolkit for linking human and earth system models called the Toolbox for Human-Earth System Integration and Scaling (THESIS). THESIS consists of models and software tools to translate, scale, and synthesize information from and between human system models and earth system models (ESMs), with initial application to linking the NCAR integrated assessment model, iPETS, with the NCAR earth system model, CESM. Initial development is focused on urban areas and agriculture, sectors that are both explicitly represented in both CESM and iPETS. Tools are being made available to the community as they are completed (see https://www2.cgd.ucar.edu/sections/tss/iam/THESIS_tools). We discuss four general types of functions that THESIS tools serve (Spatial Distribution, Spatial Properties, Consistency, and Outcome Evaluation). Tools are designed to be modular and can be combined in order to carry out more complex analyses. We illustrate their application to both the exposure of population to climate extremes and to the evaluation of climate impacts on the agriculture sector. For example, projecting exposure to climate extremes involves use of THESIS tools for spatial population, spatial urban land cover, the characteristics of both, and a tool to bring urban climate information together with spatial population information. Development of THESIS tools is continuing and open to the research community.

  16. State Event Models for the Formal Analysis of Human-Machine Interactions

    NASA Technical Reports Server (NTRS)

    Combefis, Sebastien; Giannakopoulou, Dimitra; Pecheur, Charles

    2014-01-01

    The work described in this paper was motivated by our experience with applying a framework for formal analysis of human-machine interactions (HMI) to a realistic model of an autopilot. The framework is built around a formally defined conformance relation called "fullcontrol" between an actual system and the mental model according to which the system is operated. Systems are well-designed if they can be described by relatively simple, full-control, mental models for their human operators. For this reason, our framework supports automated generation of minimal full-control mental models for HMI systems, where both the system and the mental models are described as labelled transition systems (LTS). The autopilot that we analysed has been developed in the NASA Ames HMI prototyping tool ADEPT. In this paper, we describe how we extended the models that our HMI analysis framework handles to allow adequate representation of ADEPT models. We then provide a property-preserving reduction from these extended models to LTSs, to enable application of our LTS-based formal analysis algorithms. Finally, we briefly discuss the analyses we were able to perform on the autopilot model with our extended framework.

  17. Human serum albumin interaction with honokiol studied using optical spectroscopy and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Li, Jinhua; Ren, Cuiling; Zhang, Yaheng; Liu, Xiaoyan; Yao, Xiaojun; Hu, Zhide

    2008-06-01

    The interaction of honokiol with human serum albumin (HSA) was investigated for the first time using target protein as a probe by the methods of fluorescence anisotropy, circular dichroism (CD), Fourier transform infrared (FT-IR) and molecular modeling. Upon binding with HSA, the fluorescence intensity of honokiol decreased regularly with the gradual increasing concentration of HSA. In addition, the value of fluorescence anisotropy suggested that the drug was located in a restricted environment of protein. The FT-IR spectra and CD spectra measurements showed that the secondary structure of the protein was changed by the binding of honokiol to HSA. Furthermore, the study of molecular modeling indicated that honokiol could bind to the site I (subdomain IIA) of HSA and hydrophobic interaction was the major acting force.

  18. Cortical-Subcortical Interactions in Depression: From Animal Models to Human Psychopathology

    PubMed Central

    Heller, Aaron S.

    2016-01-01

    Depression is a debilitating disorder causing significant societal and personal suffering. Improvements in identification of major depressive disorder (MDD) and its treatment are essential to reduce its toll. Recent developments in rodent models of MDD and neuroimaging of humans suffering from the disorder provide avenues through which gains can be made towards reducing its burden. In this review, new findings, integrating across rodent models and human imaging are highlighted that have yielded new insights towards a basic understanding of the disorder. In particular, this review focuses on cortical-subcortical interactions underlying the pathophysiology of MDD. In particular, evidence is accruing that dysfunction in prefrontal-subcortical circuits including the amygdala, ventral striatum (VS), hippocampus and dorsal raphe nucleus (DRN) are associated with MDD status. PMID:27013988

  19. Comparing finite difference time domain and Monte Carlo modeling of human skin interaction with terahertz radiation

    NASA Astrophysics Data System (ADS)

    Ibey, Bennett L.; Payne, Jason A.; Mixon, Dustin G.; Thomas, Robert J.; Roach, William P.

    2008-02-01

    Assessing the biological reaction to electromagnetic (EM) radiation of all frequencies and intensities is essential to the understanding of both the potential damage caused by the radiation and the inherent mechanisms within biology that respond, protect, or propagate damage to surrounding tissues. To understand this reaction, one may model the electromagnetic irradiation of tissue phantoms according to empirically measured or intelligently estimated dielectric properties. Of interest in this study is the terahertz region (0.2-2.0 THz), ranging from millimeter to infrared waves, which has been studied only recently due to lack of efficient sources. The specific interaction between this radiation and human tissue is greatly influenced by the significant EM absorption of water across this range, which induces a pronounced heating of the tissue surface. This study compares the Monte Carlo Multi-Layer (MCML) and Finite Difference Time Domain (FDTD) approaches for modeling the terahertz irradiation of human dermal tissue. Two congruent simulations were performed on a one-dimensional tissue model with unit power intensity profile. This works aims to verify the use of either technique for modeling terahertz-tissue interaction for minimally scattering tissues.

  20. Interactive 3D computer model of the human corneolimbal region: crypts, projections and stem cells.

    PubMed

    Molvaer, Rikke K; Andreasen, Arne; Heegaard, Steffen; Thomsen, Jesper S; Hjortdal, Jesper; Urbak, Steen F; Nielsen, Kim

    2013-08-01

    This study aims to clarify the existence of and to map the localization of different proposed stem cell niches in the corneal limbal region. One human eye was cut into 2200 consecutive sections. Every other section was stained with haematoxylin and eosin, digitized at low and high magnification, aligned, 3D reconstructed and visualized using interactive 3D visualization software. The visualization software has interactive tools that make free rotations in all directions possible and makes it possible to create virtual sections independent of the original cutting plan. In all, one low-magnification and 24 high-magnification interactive 3D models were created. Immunohistochemistry against stem cell markers p63 and ΔNp63α was performed as a supplement to the 3D models. Using the interactive 3D models, we identified three types of stem cell niches in the limbal region: limbal epithelial crypts (LECs), limbal crypts (LCs) and focal stromal projections (FSPs). In all, eight LECs, 25 LCs and 105 FSPs were identified in the limbal region. The LECs, LCs and FSPs were predominantly located in the superior limbal region with seven LECs, 19 LCs and 93 FSPs in the superior limbal region and one LEC, six LCs and 12 FSPs in the inferior limbal region. Only few LECs, LCs and FSPs were localized nasally and temporally. Interactive 3D models are a powerful tool that may help to shed more light on the existence and spatial localization of the different stem cell niches (LECs, LCs and FSPs) in the corneal limbal region. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  1. Development of the human aortic arch system captured in an interactive three-dimensional reference model.

    PubMed

    Rana, M Sameer; Sizarov, Aleksander; Christoffels, Vincent M; Moorman, Antoon F M

    2014-06-01

    Variations and mutations in the human genome, such as 22q11.2 microdeletion, can increase the risk for congenital defects, including aortic arch malformations. Animal models are increasingly expanding our molecular and genetic insights into aortic arch development. However, in order to justify animal-to-human extrapolations, a human morphological, and molecular reference model would be of great value, but is currently lacking. Here, we present interactive three-dimensional reconstructions of the developing human aortic arch system, supplemented with the protein distribution of developmental markers for patterning and growth, including T-box transcription factor TBX1, a major candidate for the phenotypes found in patients with the 22q11.2 microdeletion. These reconstructions and expression data facilitate unbiased interpretations, and reveal previously unappreciated aspects of human aortic arch development. Based on our reconstructions and on reported congenital anomalies of the pulmonary trunk and tributaries, we postulate that the pulmonary arteries originate from the aortic sac, rather than from the sixth pharyngeal arch arteries. Similar to mouse, TBX1 is expressed in pharyngeal mesenchyme and epithelia. The endothelium of the pharyngeal arch arteries is largely negative for TBX1 and family member TBX2 but expresses neural crest marker AP2α, which gradually decreases with ongoing development of vascular smooth muscle. At early stages, the pharyngeal arch arteries, aortic sac, and the dorsal aortae in particular were largely negative for proliferation marker Ki67, potentially an important parameter during aortic arch system remodeling. Together, our data support current animal-to-human extrapolations and future genetic and molecular analyses using animal models of congenital heart disease. © 2013 Wiley Periodicals, Inc.

  2. A componential model of human interaction with graphs: 1. Linear regression modeling

    NASA Technical Reports Server (NTRS)

    Gillan, Douglas J.; Lewis, Robert

    1994-01-01

    Task analyses served as the basis for developing the Mixed Arithmetic-Perceptual (MA-P) model, which proposes (1) that people interacting with common graphs to answer common questions apply a set of component processes-searching for indicators, encoding the value of indicators, performing arithmetic operations on the values, making spatial comparisons among indicators, and repsonding; and (2) that the type of graph and user's task determine the combination and order of the components applied (i.e., the processing steps). Two experiments investigated the prediction that response time will be linearly related to the number of processing steps according to the MA-P model. Subjects used line graphs, scatter plots, and stacked bar graphs to answer comparison questions and questions requiring arithmetic calculations. A one-parameter version of the model (with equal weights for all components) and a two-parameter version (with different weights for arithmetic and nonarithmetic processes) accounted for 76%-85% of individual subjects' variance in response time and 61%-68% of the variance taken across all subjects. The discussion addresses possible modifications in the MA-P model, alternative models, and design implications from the MA-P model.

  3. A componential model of human interaction with graphs: 1. Linear regression modeling

    NASA Technical Reports Server (NTRS)

    Gillan, Douglas J.; Lewis, Robert

    1994-01-01

    Task analyses served as the basis for developing the Mixed Arithmetic-Perceptual (MA-P) model, which proposes (1) that people interacting with common graphs to answer common questions apply a set of component processes-searching for indicators, encoding the value of indicators, performing arithmetic operations on the values, making spatial comparisons among indicators, and repsonding; and (2) that the type of graph and user's task determine the combination and order of the components applied (i.e., the processing steps). Two experiments investigated the prediction that response time will be linearly related to the number of processing steps according to the MA-P model. Subjects used line graphs, scatter plots, and stacked bar graphs to answer comparison questions and questions requiring arithmetic calculations. A one-parameter version of the model (with equal weights for all components) and a two-parameter version (with different weights for arithmetic and nonarithmetic processes) accounted for 76%-85% of individual subjects' variance in response time and 61%-68% of the variance taken across all subjects. The discussion addresses possible modifications in the MA-P model, alternative models, and design implications from the MA-P model.

  4. The role of vehicle interactions on permeation of an active through model membranes and human skin.

    PubMed

    Oliveira, G; Hadgraft, J; Lane, M E

    2012-12-01

    Previous work from this group has focused on the molecular mechanism of alcohol interaction with model membranes, by conducting thermodynamic and kinetic analyses of alcohol uptake, membrane partitioning and transport studies of a model compound (i.e. methyl paraben) in silicone membranes. In this article, similar membrane transport and partitioning studies were conducted in silicone membranes to further extend the proposed model of alcohol interactions with silicone membranes to include other vehicles more commonly used in dermal formulations, that is, isopropyl myristate (IPM), dimethyl isosorbide (DMI), polyethylene glycol (PEG) 200, PEG 400 and Transcutol P® (TC). More importantly, membrane partitioning studies were conducted using human SC to evaluate the application of the proposed model of solvent-enhanced permeation in simple model membranes for the more complex biological tissue. The findings support a model of vehicle interactions with model membranes and skin where high solvent uptake promotes drug partitioning (i.e. K) by enabling the solute to exist within the solvent fraction/solvent-rich areas inside the membrane or skin in a concentration equivalent to that in the bulk solvent/vehicle. High solvent sorption may also ultimately impact on the membrane diffusional characteristics, and thus the diffusion coefficient of the solute across the membrane. The implications for skin transport are that increased partitioning of a drug into the SC may be achieved by (i) selecting vehicles that are highly taken up by the skin and also (ii) by having a relatively high concentration (i.e. molar fraction) of the drug in the vehicle. It follows that, in cases where significant co-transport of the solvent into and across the skin may occur, its depletion from the formulation and ultimately from the skin may lead to drug crystallization, thus affecting dermal absorption.

  5. Factor interaction influences on human performance in air traffic control: the need for a multifactorial model.

    PubMed

    Edwards, Tamsyn; Sharples, Sarah; Wilson, John R; Kirwan, Barry

    2012-01-01

    In air traffic management (ATM) knowledge of the impact of human factors on performance is critical to address safety incidents. Previous research has largely focused on the effects of single factors on performance which has resulted in a comprehensive understanding of single factor effects. In current control environments however, the residual threats for incidents often result from the interaction of multiple human factors and the resulting cumulative impact on performance. This research uses a literature review, an analysis of over 400 European aviation incident reports and finally a survey of ATM professionals to assess the need for a multifactorial model of performance. Literature findings suggest that Human Factors approaches are fundamentally single-factor in nature, which is out of step with real ATM working contexts. An incident report analysis, supported by a survey of air traffic experts, suggests that multiple factor incident causation exists. This discrepancy suggests the need for a new approach to looking at how incidents occur, and their factors managed, on a day-to-day basis. The proposed solution is a multifactorial model of human performance.

  6. GABAergic modulation of human social interaction in a prisoner's dilemma model by acute administration of alprazolam.

    PubMed

    Lane, Scott D; Gowin, Joshua L

    2009-10-01

    Recent work in neuroeconomics has used game theory paradigms to examine neural systems that subserve human social interaction and decision making. Attempts to modify social interaction through pharmacological manipulation have been less common. Here we show dose-dependent modification of human social behavior in a prisoner's dilemma model after acute administration of the γ-aminobutyric acid (GABA)-A modulating benzodiazepine alprazolam. Nine healthy adults received doses of placebo, 0.5, 1.0, and 2.0 mg alprazolam in a counterbalanced within-subject design, while completing multiple test blocks per day on an iterated prisoner's dilemma game. During test blocks in which peak subjective effects of alprazolam were reported, cooperative choices were significantly decreased as a function of dose. Consistent with previous reports showing that high acute doses of GABA-modulating drugs are associated with violence and other antisocial behavior, our data suggest that at sufficiently high doses, alprazolam can decrease cooperation. These behavioral changes may be facilitated by changes in inhibitory control facilitated by GABA. Game theory paradigms may prove useful in behavioral pharmacology studies seeking to measure social interaction, and may help inform the emerging field of neuroeconomics.

  7. Interaction of cyproheptadine hydrochloride with human serum albumin using spectroscopy and molecular modeling methods.

    PubMed

    Jiang, Hua; Chen, Rongrong; Wang, Hongcui; Pu, Hanlin

    2013-01-01

    The interaction between cyproheptadine hydrochloride (CYP) and human serum albumin (HSA) was investigated by fluorescence spectroscopy, UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and molecular modeling at a physiological pH (7.40). Fluorescence of HSA was quenched remarkably by CYP and the quenching mechanism was considered as static quenching since it formed a complex. The association constants Ka and number of binding sites n were calculated at different temperatures. According to Förster's theory of non-radiation energy transfer, the distance r between donor (human serum albumin) and acceptor (cyproheptadine hydrochloride) was obtained. The effect of common ions on the binding constant was also investigated. The effect of CYP on the conformation of HSA was analyzed using FT-IR, synchronous fluorescence spectroscopy and 3D fluorescence spectra. The thermodynamic parameters ΔH and ΔS were calculated to be -14.37 kJ mol(-1) and 38.03 J mol(-1) K(-1), respectively, which suggested that hydrophobic forces played a major role in stabilizing the HSA-CYP complex. In addition, examination of molecular modeling indicated that CYP could bind to site I of HSA and that hydrophobic interaction was the major acting force, which was in agreement with binding mode studies.

  8. Evaluation of Two Models for Human Topoisomerase I Interaction with dsDNA and Camptothecin Derivatives

    PubMed Central

    Laco, Gary S.

    2011-01-01

    Human topoisomerase I (Top1) relaxes supercoiled DNA during cell division. Camptothecin stabilizes Top1/dsDNA covalent complexes which ultimately results in cell death, and this makes Top1 an anti-cancer target. There are two current models for how camptothecin and derivatives bind to Top1/dsDNA covalent complexes (Staker, et al., 2002, Proc Natl Acad Sci USA 99: 15387–15392; and Laco, et al., 2004, Bioorg Med Chem 12: 5225–5235). The interaction energies between bound camptothecin, and derivatives, and Top1/dsDNA in the two models were calculated. The published structure-activity-relationships for camptothecin and derivatives correlated with the interaction energies for camptothecin and derivatives in the Laco et al. model, however, this was not the case for several camptothecin derivatives in the Stacker et al. model. By defining the binding orientation of camptothecin and derivatives in the Top1/dsDNA active-site these results allow for the rational design of potentially more efficacious camptothecin derivatives. PMID:21912628

  9. Implementing Lumberjacks and Black Swans Into Model-Based Tools to Support Human-Automation Interaction.

    PubMed

    Sebok, Angelia; Wickens, Christopher D

    2017-03-01

    The objectives were to (a) implement theoretical perspectives regarding human-automation interaction (HAI) into model-based tools to assist designers in developing systems that support effective performance and (b) conduct validations to assess the ability of the models to predict operator performance. Two key concepts in HAI, the lumberjack analogy and black swan events, have been studied extensively. The lumberjack analogy describes the effects of imperfect automation on operator performance. In routine operations, an increased degree of automation supports performance, but in failure conditions, increased automation results in more significantly impaired performance. Black swans are the rare and unexpected failures of imperfect automation. The lumberjack analogy and black swan concepts have been implemented into three model-based tools that predict operator performance in different systems. These tools include a flight management system, a remotely controlled robotic arm, and an environmental process control system. Each modeling effort included a corresponding validation. In one validation, the software tool was used to compare three flight management system designs, which were ranked in the same order as predicted by subject matter experts. The second validation compared model-predicted operator complacency with empirical performance in the same conditions. The third validation compared model-predicted and empirically determined time to detect and repair faults in four automation conditions. The three model-based tools offer useful ways to predict operator performance in complex systems. The three tools offer ways to predict the effects of different automation designs on operator performance.

  10. Development of an Anatomically Accurate Finite Element Human Ocular Globe Model for Blast-Related Fluid-Structure Interaction Studies

    DTIC Science & Technology

    2017-02-01

    ARL-TR-7945 ● FEB 2017 US Army Research Laboratory Development of an Anatomically Accurate Finite Element Human Ocular Globe...ARL-TR-7945 ● FEB 2017 US Army Research Laboratory Development of an Anatomically Accurate Finite Element Human Ocular Globe Model...Finite Element Human Ocular Globe Model for Blast-Related Fluid-Structure Interaction Studies 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  11. A computational fluid-structure interaction model for plaque vulnerability assessment in atherosclerotic human coronary arteries

    NASA Astrophysics Data System (ADS)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza; Haghpanahi, Mohammad

    2014-04-01

    Coronary artery disease is responsible for a third of global deaths worldwide. Computational simulations of blood flow can be used to understand the interactions of artery/plaque and blood in coronary artery disease and to better predict the rupture of atherosclerotic plaques. So far, the mechanical properties of animals' coronary artery have been mostly used for hemodynamic simulation of atherosclerotic arteries. The mechanical properties of animals' coronary arteries are often not accurate enough and can be only used for an approximate estimation and comparative assessment of the cognate parameters in human. In this study, a three-dimensional (3D) computational fluid-structure interactions model with three different plaque types is presented to perform a more accurate plaque vulnerability assessment for human atherosclerotic plaques. The coronary arteries of twenty-two male individuals were removed during autopsy and subjected to uniaxial tensile loading. The hyperelastic material coefficients of coronary arteries were calculated and implemented to the computational model. The fully coupled fluid and structure models were solved using the explicit dynamics finite element code LS-DYNA. The normal and shear stresses induced within the plaques were significantly affected by different plaque types. The highest von Mises (153 KPa) and shear (57 KPa) stresses were observed for hypocellular plaques, while the lowest von Mises (70 KPa) and shear (39 KPa) stresses were observed on the stiffer calcified plaques. The results suggest that the risk of plaque rupture due to blood flow is lower for cellular and hypocellular plaques, while higher for calcified plaques with low fracture stresses.

  12. Modeling of protein-anion exchange resin interaction for the human growth hormone charge variants.

    PubMed

    Lapelosa, Mauro; Patapoff, Thomas W; Zarraga, Isidro E

    2015-12-01

    Modeling ion exchange chromatography (IEC) behavior has generated significant interest because of the wide use of IEC as an analytical technique as well as a preparative protein purification process; indeed there is a need for better understanding of what drives the unique behavior of protein charge variants. We hypothesize that a complex protein molecule, which contains both hydrophobic and charged moieties, would interact strongly with an in silico designed resin through charged electrostatic patches on the surface of the protein. In the present work, variants of recombinant human growth hormone that mimic naturally-occurring deamidation products were produced and characterized in silico. The study included these four variants: rhGH, N149D, N152D, and N149D/N152D. Poisson-Boltzmann calculations were used to determine surface electrostatic potential. Metropolis Monte Carlo simulations were carried out with the resulting variants to simulate IEC systems, examining the free energy of the interaction of the protein with an in silico anion exchange column represented by polylysine polypeptide. The results show that the charge variants have different average binding energies and the free energy of interaction can be used to predict the retention time for the different variants.

  13. A linear canal-otolith interaction model to describe the human vestibulo-ocular reflex.

    PubMed

    Crane, B T; Demer, J L

    1999-08-01

    A control systems model of the vestibulo-ocular reflex (VOR) originally derived for yaw rotation about an eccentric axis (Crane et al. 1997) was applied to data collected during ambulation and dynamic posturography. The model incorporates a linear summation of an otolith response due to head translation scaled by target distance, adding to a semi-circular canal response that depends only on angular head rotation. The results of the model were compared with human experimental data by supplying head angular velocity as determined by magnetic search coil recording as the input for the canal branch of the model and supplying linear acceleration as determined by flux gate magnetometer measurements of otolith position. The model was fit to data by determining otolith weighting that enabled the model to best fit the data. We fit to the model experimental data from normal subjects who were: standing quietly, walking, running, or making active sinusoidal head movements. We also fit data obtained during dynamic posturography tasks of: standing on a platform sliding in a horizontal plane at 0.2 Hz, standing directly on a platform tilting at 0.1 Hz, and standing on the tilting platform buffered by a 5-cm thick foam rubber cushion. Each task was done with the subject attending a target approximately 500, 100, or 50 cm distant, both in light and darkness. The model accurately predicted the observed VOR response during each test. Greater otolith weighting was required for near targets for nearly all activities, consistent with weights for the otolith component found in previous studies employing imposed rotations. The only exceptions were for vertical axis motion during standing, sliding, and tilting when the platform was buffered with foam rubber. In the horizontal axis, the model always fit near target data better with a higher otolith component. Otolith weights were similar with the target visible and in darkness. The model predicts eye movement during both passive whole

  14. Model of human/liquid cooling garment interaction for space suit automatic thermal control.

    PubMed

    Nyberg, K L; Diller, K R; Wissler, E H

    2001-02-01

    The Wissler human thermoregulation model was augmented to incorporate simulation of a space suit thermal control system that includes interaction with a liquid cooled garment (LCG) and ventilation gas flow through the suit. The model was utilized in the design process of an automatic controller intended to maintain thermal neutrality of an exercising subject wearing a liquid cooling garment. An experimental apparatus was designed and built to test the efficacy of specific physiological state measurements to provide feedback data for input to the automatic control algorithm. Control of the coolant inlet temperature to the LCG was based on evaluation of transient physiological parameters that describe the thermal state of the subject, including metabolic rate, skin temperatures, and core temperature. Experimental evaluation of the control algorithm function was accomplished in an environmental chamber under conditions that simulated the thermal environment of a space suit and transient metabolic work loads typical of astronaut extravehicular activity (EVA). The model was also applied to analyze experiments to evaluate performance of the automatic control system in maintaining thermal comfort during extensive transient metabolic profiles for a range of environmental temperatures. Finally, the model was used to predict the efficacy of the LCG thermal controller for providing thermal comfort for a variety of regiments that may be encountered in future space missions. Simulations with the Wissler model accurately predicted the thermal interaction between the subject and LCG for a wide range of metabolic profiles and environmental conditions and matched the function of the automatic temperature controller for inlet cooling water to the LCG.

  15. Neuro-immune interactions of neural stem cell transplants: from animal disease models to human trials.

    PubMed

    Giusto, Elena; Donegà, Matteo; Cossetti, Chiara; Pluchino, Stefano

    2014-10-01

    Stem cell technology is a promising branch of regenerative medicine that is aimed at developing new approaches for the treatment of severely debilitating human diseases, including those affecting the central nervous system (CNS). Despite the increasing understanding of the mechanisms governing their biology, the application of stem cell therapeutics remains challenging. The initial idea that stem cell transplants work in vivo via the replacement of endogenous cells lost or damaged owing to disease has been challenged by accumulating evidence of their therapeutic plasticity. This new concept covers the remarkable immune regulatory and tissue trophic effects that transplanted stem cells exert at the level of the neural microenvironment to promote tissue healing via combination of immune modulatory and tissue protective actions, while retaining predominantly undifferentiated features. Among a number of promising candidate stem cell sources, neural stem/precursor cells (NPCs) are under extensive investigation with regard to their therapeutic plasticity after transplantation. The significant impact in vivo of experimental NPC therapies in animal models of inflammatory CNS diseases has raised great expectations that these stem cells, or the manipulation of the mechanisms behind their therapeutic impact, could soon be translated to human studies. This review aims to provide an update on the most recent evidence of therapeutically-relevant neuro-immune interactions following NPC transplants in animal models of multiple sclerosis, cerebral stroke and traumas of the spinal cord, and consideration of the forthcoming challenges related to the early translation of some of these exciting experimental outcomes into clinical medicines.

  16. Modeling strategic behavior in human-automation interaction - Why an 'aid' can (and should) go unused

    NASA Technical Reports Server (NTRS)

    Kirlik, Alex

    1993-01-01

    Task-offload aids (e.g., an autopilot, an 'intelligent' assistant) can be selectively engaged by the human operator to dynamically delegate tasks to automation. Introducing such aids eliminates some task demands but creates new ones associated with programming, engaging, and disengaging the aiding device via an interface. The burdens associated with managing automation can sometimes outweigh the potential benefits of automation to improved system performance. Aid design parameters and features of the overall multitask context combine to determine whether or not a task-offload aid will effectively support the operator. A modeling and sensitivity analysis approach is presented that identifies effective strategies for human-automation interaction as a function of three task-context parameters and three aid design parameters. The analysis and modeling approaches provide resources for predicting how a well-adapted operator will use a given task-offload aid, and for specifying aid design features that ensure that automation will provide effective operator support in a multitask environment.

  17. Modeling strategic behavior in human-automation interaction - Why an 'aid' can (and should) go unused

    NASA Technical Reports Server (NTRS)

    Kirlik, Alex

    1993-01-01

    Task-offload aids (e.g., an autopilot, an 'intelligent' assistant) can be selectively engaged by the human operator to dynamically delegate tasks to automation. Introducing such aids eliminates some task demands but creates new ones associated with programming, engaging, and disengaging the aiding device via an interface. The burdens associated with managing automation can sometimes outweigh the potential benefits of automation to improved system performance. Aid design parameters and features of the overall multitask context combine to determine whether or not a task-offload aid will effectively support the operator. A modeling and sensitivity analysis approach is presented that identifies effective strategies for human-automation interaction as a function of three task-context parameters and three aid design parameters. The analysis and modeling approaches provide resources for predicting how a well-adapted operator will use a given task-offload aid, and for specifying aid design features that ensure that automation will provide effective operator support in a multitask environment.

  18. Modeling strategic behavior in human-automation interaction: why an "aid" can (and should) go unused.

    PubMed

    Kirlik, A

    1993-06-01

    Task-offload aids (e.g., an autopilot, an "intelligent" assistant) can be selectively engaged by the human operator to dynamically delegate tasks to automation. Introducing such aids eliminates some task demands but creates new ones associated with programming, engaging, and disengaging the aiding device via an interface. The burdens associated with managing automation can sometimes outweigh the potential benefits of automation to improved system performance. Aid design parameters and features of the overall multitask context combine to determine whether or not a task-offload aid will effectively support the operator. A modeling and sensitivity analysis approach is presented that identifies effective strategies for human-automation interaction as a function of three task-context parameters and three aid design parameters. The analysis and modeling approaches provide resources for predicting how a well-adapted operator will use a given task-offload aid, and for specifying aid design features that ensure that automation will provide effective operator support in a multitask environment.

  19. Neuro-immune interactions of neural stem cell transplants: From animal disease models to human trials

    PubMed Central

    Cossetti, Chiara; Pluchino, Stefano

    2014-01-01

    Stem cell technology is a promising branch of regenerative medicine that is aimed at developing new approaches for the treatment of severely debilitating human diseases, including those affecting the central nervous system (CNS). Despite the increasing understanding of the mechanisms governing their biology, the application of stem cell therapeutics remains challenging. The initial idea that stem cell transplants work in vivo via the replacement of endogenous cells lost or damaged owing to disease has been challenged by accumulating evidence of their therapeutic plasticity. This new concept covers the remarkable immune regulatory and tissue trophic effects that transplanted stem cells exert at the level of the neural microenvironment to promote tissue healing via combination of immune modulatory and tissue protective actions, while retaining predominantly undifferentiated features. Among a number of promising candidate stem cell sources, neural stem/precursor cells (NPCs) are under extensive investigation with regard to their therapeutic plasticity after transplantation. The significant impact in vivo of experimental NPC therapies in animal models of inflammatory CNS diseases has raised great expectations that these stem cells, or the manipulation of the mechanisms behind their therapeutic impact, could soon be translated to human studies. This review aims to provide an update on the most recent evidence of therapeutically-relevant neuroimmune interactions following NPC transplants in animal models of multiple sclerosis, cerebral stroke and traumas of the spinal cord, and consideration of the forthcoming challenges related to the early translation of some of these exciting experimental outcomes into clinical medicines. PMID:23507035

  20. Escaping from Babel: Improving the Terminology of Mental Models in the Literature of Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Turner, James M.; Belanger, Francois Papik

    1996-01-01

    Discusses the problem of establishing terminology for mental models, attempts to sort out the various meanings found in the literature, and offers definitions that could help in developing a more standardized terminology for discussing issues of concern to researchers in human-computer interaction. The role of mental models in learning and using…

  1. Using hydraulic modeling to simulate human interactions with water resources in an Omani irrigation system

    NASA Astrophysics Data System (ADS)

    Xanthopoulou, Themis; Ertsen, Maurits; Düring, Bleda; Kolen, Jan

    2017-04-01

    In the dry Southern Oman, more than a thousand years ago, a large water system that connected the mountain mass with the coastal region was constructed. Its length (up to 30 km) and the fact that the coastal region has a rich groundwater aquifer create confusion as to why the system was initially built. Nonetheless, it was abandoned a couple of centuries later only to be partially revived by small farming communities in the 17th to 18th century. The focus of our research is one of the irrigation systems that used the water conveyed from the large water system. Not much is known about these small irrigation systems functioning in the Wadi Al Jizzi of the greater Sohar region. There are no written records and we can only make guesses about the way the systems were managed based on ethnographical studies and the traditional Omani techniques. On the other hand, the good preservation state of the canals offers a great opportunity for hydraulic reconstruction of irrigation events. More than that, the material remains suggest and at the same time limit the ways in which humans interacted with the system and the water resources of the region. All irrigation activities and some daily activities had to be realized through the canal system and only if the canal system permits it these actions would have been feasible. We created a conceptual model of irrigation that includes the human agent and feedback mechanisms through hydraulics and then we simulated irrigation events using the Sobek software. Scenarios and sensibility analysis were used to address the unknown aspects of the system. Our research yielded insights about the way the farming community interacted with the larger water system, the levels of co-ordination and co-operation required for successful irrigation and the predisposition of conflict and power relations.

  2. Human Computer Interaction

    NASA Astrophysics Data System (ADS)

    Bhagwani, Akhilesh; Sengar, Chitransh; Talwaniper, Jyotsna; Sharma, Shaan

    2012-08-01

    The paper basically deals with the study of HCI (Human computer interaction) or BCI(Brain-Computer-Interfaces) Technology that can be used for capturing brain signals and translating them into commands that allow humans to control (just by thinking) devices such as computers, robots, rehabilitation technology and virtual reality environments. The HCI is based as a direct communication pathway between the brain and an external device. BCIs are often aimed at assisting, augmenting, or repairing human cognitive or sensory-motor functions.The paper also deals with many advantages of BCI Technology along with some of its applications and some major drawbacks.

  3. A Collaborative 20 Questions Model for Target Search with Human-Machine Interaction

    DTIC Science & Technology

    2013-05-01

    recognition ( ATR ) sensor. In the ATR set- ting the objective of the human-machine-interaction is to collabo- rate on estimating an unknown target location...where the human is repeatedly queried about target location in order to improve ATR performance. We propose a 20 questions framework for studying the...SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 5 19a. NAME OF RESPONSIBLE

  4. Towards a Model of Human Resource Solutions for Achieving Intergenerational Interaction in Organisations

    ERIC Educational Resources Information Center

    McGuire, David; By, Rune Todnem; Hutchings, Kate

    2007-01-01

    Purpose: Achieving intergenerational interaction and avoiding conflict is becoming increasingly difficult in a workplace populated by three generations--Baby Boomers, Generation X-ers and Generation Y-ers. This paper presents a model and proposes HR solutions towards achieving co-operative generational interaction. Design/methodology/approach:…

  5. Towards a Model of Human Resource Solutions for Achieving Intergenerational Interaction in Organisations

    ERIC Educational Resources Information Center

    McGuire, David; By, Rune Todnem; Hutchings, Kate

    2007-01-01

    Purpose: Achieving intergenerational interaction and avoiding conflict is becoming increasingly difficult in a workplace populated by three generations--Baby Boomers, Generation X-ers and Generation Y-ers. This paper presents a model and proposes HR solutions towards achieving co-operative generational interaction. Design/methodology/approach:…

  6. Embedded human computer interaction.

    PubMed

    Baber, Christopher; Baumann, Konrad

    2002-05-01

    In this paper, human interaction with embedded or ubiquitous technology is considered. The techniques focus on the use of what might be termed "everyday" objects and actions as a means of controlling (or otherwise interacting with) technology. While this paper is not intended to be an exhaustive review, it does present a view of the immediate future of human-computer interaction (HCI) in which users move beyond the desktop to where interacting with technology becomes merged with other activity. At one level this places HCI in the context of other forms of personal and domestic technologies. At another level, this raises questions as to how people will interact with technologies of the future. Until now, HCI had often relied on people learning obscure command sets or learning to recognise words and objects on their computer screen. The most significant advance in HCI (the invention of the WIMP interface) is already some 40 years old. Thus, the future of HCI might be one in which people are encouraged (or at least allowed) to employ the skills that they have developed during their lives in order to interact with technology, rather than being forced to learn and perfect new skills.

  7. Five Papers on Human-Machine Interaction.

    ERIC Educational Resources Information Center

    Norman, Donald A.

    Different aspects of human-machine interaction are discussed in the five brief papers that comprise this report. The first paper, "Some Observations on Mental Models," discusses the role of a person's mental model in the interaction with systems. The second paper, "A Psychologist Views Human Processing: Human Errors and Other…

  8. Design Science in Human-Computer Interaction: A Model and Three Examples

    ERIC Educational Resources Information Center

    Prestopnik, Nathan R.

    2013-01-01

    Humanity has entered an era where computing technology is virtually ubiquitous. From websites and mobile devices to computers embedded in appliances on our kitchen counters and automobiles parked in our driveways, information and communication technologies (ICTs) and IT artifacts are fundamentally changing the ways we interact with our world.…

  9. Design Science in Human-Computer Interaction: A Model and Three Examples

    ERIC Educational Resources Information Center

    Prestopnik, Nathan R.

    2013-01-01

    Humanity has entered an era where computing technology is virtually ubiquitous. From websites and mobile devices to computers embedded in appliances on our kitchen counters and automobiles parked in our driveways, information and communication technologies (ICTs) and IT artifacts are fundamentally changing the ways we interact with our world.…

  10. Human Development Theories: A Comparison of Classic Human Development Theorists and the Implications for a Model of Developmental Social Interaction.

    ERIC Educational Resources Information Center

    Ollhoff, Jim

    This paper explores several theories of human development, with particular attention to the development of social interaction. Part 1 compares and contrasts major developmental theories, including those of Freud, Erikson, Piaget, Kohlberg, Kegan, Fowler, and Selman. From birth to 1 year, infants are laying the foundation that will guide their…

  11. Investigation the interaction of Daphnin with human serum albumin using optical spectroscopy and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Zhu, Jinhua; Wu, Liye; Zhang, Qingyou; Chen, Xingguo; Liu, Xiuhua

    2012-09-01

    The interaction between Daphnin with human serum albumin has been studied for the first time by spectroscopic methods including fluorescence quenching technology, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that Daphnin can quench the intrinsic fluorescence of HSA by static quenching and there is a single class of binding site on HSA. In addition, the studies of CD spectroscopy and FT-IR spectroscopy showed that the protein secondary structure changed with increases of α-helices at the drug to protein molar ratio of 2. Furthermore, the thermodynamic functions ΔH0 and ΔS0 for the reaction were calculated to be 11.626 kJ mol-1 and 118.843 J mol-1 K-1 according to Van't Hoff equation. The thermodynamic parameters (ΔH0 and ΔS0) and the molecular modeling study indicated that hydrophobic force played an important role to stabilize the Daphnin-HSA complex, and Daphnin could bind within the subdomain IIA of the HSA.

  12. Investigation the interaction of Daphnin with human serum albumin using optical spectroscopy and molecular modeling methods.

    PubMed

    Zhu, Jinhua; Wu, Liye; Zhang, Qingyou; Chen, Xingguo; Liu, Xiuhua

    2012-09-01

    The interaction between Daphnin with human serum albumin has been studied for the first time by spectroscopic methods including fluorescence quenching technology, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that Daphnin can quench the intrinsic fluorescence of HSA by static quenching and there is a single class of binding site on HSA. In addition, the studies of CD spectroscopy and FT-IR spectroscopy showed that the protein secondary structure changed with increases of α-helices at the drug to protein molar ratio of 2. Furthermore, the thermodynamic functions ΔH(0) and ΔS(0) for the reaction were calculated to be 11.626 kJ mol(-1) and 118.843 J mol(-1)K(-1) according to Van't Hoff equation. The thermodynamic parameters (ΔH(0) and ΔS(0)) and the molecular modeling study indicated that hydrophobic force played an important role to stabilize the Daphnin-HSA complex, and Daphnin could bind within the subdomain IIA of the HSA. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Computational modeling of blast wave interaction with a human body and assessment of traumatic brain injury

    NASA Astrophysics Data System (ADS)

    Tan, X. G.; Przekwas, A. J.; Gupta, R. K.

    2017-07-01

    The modeling of human body biomechanics resulting from blast exposure poses great challenges because of the complex geometry and the substantial material heterogeneity. We developed a detailed human body finite element model representing both the geometry and the materials realistically. The model includes the detailed head (face, skull, brain and spinal cord), the neck, the skeleton, air cavities (lungs) and the tissues. Hence, it can be used to properly model the stress wave propagation in the human body subjected to blast loading. The blast loading on the human was generated from a simulated C4 explosion. We used the highly scalable solvers in the multi-physics code CoBi for both the blast simulation and the human body biomechanics. The meshes generated for these simulations are of good quality so that relatively large time-step sizes can be used without resorting to artificial time scaling treatments. The coupled gas dynamics and biomechanics solutions were validated against the shock tube test data. The human body models were used to conduct parametric simulations to find the biomechanical response and the brain injury mechanism due to blasts impacting the human body. Under the same blast loading condition, we showed the importance of inclusion of the whole body.

  14. Semantic Likelihood Models for Bayesian Inference in Human-Robot Interaction

    NASA Astrophysics Data System (ADS)

    Sweet, Nicholas

    Autonomous systems, particularly unmanned aerial systems (UAS), remain limited in au- tonomous capabilities largely due to a poor understanding of their environment. Current sensors simply do not match human perceptive capabilities, impeding progress towards full autonomy. Recent work has shown the value of humans as sources of information within a human-robot team; in target applications, communicating human-generated 'soft data' to autonomous systems enables higher levels of autonomy through large, efficient information gains. This requires development of a 'human sensor model' that allows soft data fusion through Bayesian inference to update the probabilistic belief representations maintained by autonomous systems. Current human sensor models that capture linguistic inputs as semantic information are limited in their ability to generalize likelihood functions for semantic statements: they may be learned from dense data; they do not exploit the contextual information embedded within groundings; and they often limit human input to restrictive and simplistic interfaces. This work provides mechanisms to synthesize human sensor models from constraints based on easily attainable a priori knowledge, develops compression techniques to capture information-dense semantics, and investigates the problem of capturing and fusing semantic information contained within unstructured natural language. A robotic experimental testbed is also developed to validate the above contributions.

  15. A Systems Model for Immune Cell Interactions Unravels the Mechanism of Inflammation in Human Skin

    PubMed Central

    Umezawa, Yoshinori; Kotov, Nikolay V.; Williams, Gareth; Clop, Alex; Ainali, Crysanthi; Ouzounis, Christos; Tsoka, Sophia; Nestle, Frank O.

    2010-01-01

    Inflammation is characterized by altered cytokine levels produced by cell populations in a highly interdependent manner. To elucidate the mechanism of an inflammatory reaction, we have developed a mathematical model for immune cell interactions via the specific, dose-dependent cytokine production rates of cell populations. The model describes the criteria required for normal and pathological immune system responses and suggests that alterations in the cytokine production rates can lead to various stable levels which manifest themselves in different disease phenotypes. The model predicts that pairs of interacting immune cell populations can maintain homeostatic and elevated extracellular cytokine concentration levels, enabling them to operate as an immune system switch. The concept described here is developed in the context of psoriasis, an immune-mediated disease, but it can also offer mechanistic insights into other inflammatory pathologies as it explains how interactions between immune cell populations can lead to disease phenotypes. PMID:21152006

  16. Molecular interaction study of flavonoids with human serum albumin using native mass spectrometry and molecular modeling.

    PubMed

    Wang, Bohong; Qin, Qian; Chang, Mengmeng; Li, Shuyan; Shi, Xianzhe; Xu, Guowang

    2017-08-24

    Noncovalent interactions between proteins and small-molecule ligands widely exist in biological bodies and play significant roles in many physiological and pathological processes. Native mass spectrometry (MS) has emerged as a new powerful tool to study noncovalent interactions by directly analyzing the ligand-protein complexes. In this work, an ultrahigh-resolution native MS method based on a 15-T SolariX XR Fourier transform ion cyclotron resonance mass spectrometer was firstly used to investigate the interaction between human serum albumin (HSA) and flavonoids. Various flavonoids with similar structure were selected to unravel the relationship between the structure of flavonoids and their binding affinity for HSA. It was found that the position of the hydroxyl groups and double bond of flavonoids could influence the noncovalent interaction. Through a competitive experiment between HSA binding site markers and apigenin, the subdomain IIA (site 1) of HSA was determined as the binding site for flavonoids. Moreover, a cooperative allosteric interaction between apigenin and ibuprofen was found from their different HSA binding sites, which was further verified by circular dichroism spectroscopy and molecular docking studies. These results show that native MS is a useful tool to investigate the molecular interaction between a protein and its ligands. Graphical abstract Unravel the relationship between the structure of flavonoids and their binding affinity to HSA by native MS.

  17. Acetaminophen interacts with human hemoglobin: optical, physical and molecular modeling studies.

    PubMed

    Seal, Paromita; Sikdar, Jyotirmoy; Roy, Amartya; Haldar, Rajen

    2017-05-01

    Acetaminophen, a widely used analgesic and antipyretic drug has ample affinity to bind globular proteins. Here, we have illustrated a substantive study pertaining to the interaction of acetaminophen with human hemoglobin (HHb). Different spectroscopic (absorption, fluorescence, and circular dichroism (CD) spectroscopy), calorimetric, and molecular docking techniques have been employed in this study. Acetaminophen-induced graded alterations in absorbance and fluorescence of HHb confirm their interaction. Analysis of fluorescence quenching at different temperature and data obtained from isothermal titration calorimetry indicate that the interaction is static and the HHb has one binding site for the drug. The negative values of Gibbs energy change (ΔG(0)) and enthalpy changes (ΔH(0)) and positive value of entropy change (ΔS(0)) strongly suggest that it is entropy-driven spontaneous and exothermic reaction. The reaction involves hydrophobic pocket of the protein which is further stabilized by hydrogen bonding as evidenced from ANS and sucrose binding studies. These findings were also supported by molecular docking simulation study using AutoDock 4.2. The interaction influences structural integrity as well as functional properties of HHb as evidenced by CD spectroscopy, increased rate of co-oxidation and decreased esterase activity of HHb. So, from these findings, we may conclude that acetaminophen interacts with HHb through hydrophobic and hydrogen bonding, and the interaction perturbs the structural and functional properties of HHb.

  18. Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Sandor, Aniko; Cross, E. Vincent, II; Chang, Mai Lee

    2015-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces affect the human's ability to perform tasks effectively and efficiently when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. For efficient and effective remote navigation of a rover, a human operator needs to be aware of the robot's environment. However, during teleoperation, operators may get information about the environment only through a robot's front-mounted camera causing a keyhole effect. The keyhole effect reduces situation awareness which may manifest in navigation issues such as higher number of collisions, missing critical aspects of the environment, or reduced speed. One way to compensate for the keyhole effect and the ambiguities operators experience when they teleoperate a robot is adding multiple cameras and including the robot chassis in the camera view. Augmented reality, such as overlays, can also enhance the way a person sees objects in the environment or in camera views by making them more visible. Scenes can be augmented with integrated telemetry, procedures, or map information. Furthermore, the addition of an exocentric (i.e., third-person) field of view from a camera placed in the robot's environment may provide operators with the additional information needed to gain spatial awareness of the robot. Two research studies investigated possible mitigation approaches to address the keyhole effect: 1) combining the inclusion of the robot chassis in the camera view with augmented reality overlays, and 2) modifying the camera

  19. Spectroscopic analysis and molecular modeling on the interaction of jatrorrhizine with human serum albumin (HSA)

    NASA Astrophysics Data System (ADS)

    Li, Junfen; Li, Jinzeng; Jiao, Yong; Dong, Chuan

    2014-01-01

    In this work, the interaction of jatrorrhizine with human serum albumin (HSA) was studied by means of UV-vis and fluorescence spectra. The intrinsic fluorescence of HSA was quenched by jatrorrhizine, which was rationalized in terms of the static quenching mechanism. The results show that jatrorrhizine can obviously bind to HSA molecules. According to fluorescence quenching calculations, the bimolecular quenching constant (kq), apparent quenching constant (KSV) at different temperatures were obtained. The binding constants K are 4059 L mol-1 and 1438 L mol-1 at 299 K and 304 K respectively, and the number of binding sites n is almost 1. The thermodynamic parameters determined by the Van't Hoff analysis of the binding constants (ΔH -12.25 kJ mol-1 and ΔS 28.17 J mol-1 K-1) clearly indicate that the electrostatic force plays a major role in the process. The efficiency of energy transfer and the distance between the donor (HSA) and the acceptor (jatrorrhizine) were calculated as 22.2% and 3.19 nm according to Föster's non-radiative energy transfer theory. In addition, synchronous fluorescence spectroscopy reveals that jatrorrhizine can influence HSA's microstructure. That is, jatrorrhizine is more vicinal to tryptophane (Trp) residue than to tyrosine (Tyr) residue and the damage site is also mainly at Trp residue. Molecular modeling result shows that jatrorrhizine-HSA complex formed not only on the basis of electrostatic forces, but also on the basis of π-π staking and hydrogen bond. The research results will offer a reference for the studies on the biological effects and action mechanism of small molecule with protein.

  20. Dissection of the host-pathogen interaction in human tuberculosis using a bioengineered 3-dimensional model

    PubMed Central

    Tezera, Liku B; Bielecka, Magdalena K; Chancellor, Andrew; Reichmann, Michaela T; Shammari, Basim Al; Brace, Patience; Batty, Alex; Tocheva, Annie; Jogai, Sanjay; Marshall, Ben G; Tebruegge, Marc; Jayasinghe, Suwan N; Mansour, Salah; Elkington, Paul T

    2017-01-01

    Cell biology differs between traditional cell culture and 3-dimensional (3-D) systems, and is modulated by the extracellular matrix. Experimentation in 3-D presents challenges, especially with virulent pathogens. Mycobacterium tuberculosis (Mtb) kills more humans than any other infection and is characterised by a spatially organised immune response and extracellular matrix remodelling. We developed a 3-D system incorporating virulent mycobacteria, primary human blood mononuclear cells and collagen–alginate matrix to dissect the host-pathogen interaction. Infection in 3-D led to greater cellular survival and permitted longitudinal analysis over 21 days. Key features of human tuberculosis develop, and extracellular matrix integrity favours the host over the pathogen. We optimised multiparameter readouts to study emerging therapeutic interventions: cytokine supplementation, host-directed therapy and immunoaugmentation. Each intervention modulates the host-pathogen interaction, but has both beneficial and harmful effects. This methodology has wide applicability to investigate infectious, inflammatory and neoplastic diseases and develop novel drug regimes and vaccination approaches. DOI: http://dx.doi.org/10.7554/eLife.21283.001 PMID:28063256

  1. HIV Interaction With Human Host: HIV-2 As a Model of a Less Virulent Infection.

    PubMed

    Azevedo-Pereira, José Miguel; Santos-Costa, Quirina

    2016-01-01

    HIV-1 and HIV-2 are the causal agents of AIDS. While similar in many ways, a significant amount of data suggests that HIV-2 is less virulent than HIV-1. In fact, HIV-2 infection is characterized by a longer asymptomatic stage and lower transmission rate, and the majority of HIV-2-infected patients can be classified as long-term non-progressors or elite controllers. The mechanisms underlying the ability of human host to naturally control HIV-2 infection are far from being completely understood. The identification of the differences between HIV-1 and HIV-2 interactions with human host cells could provide important insights into several aspects of retroviral pathogenesis that remain elusive, with significant implications for HIV vaccine development and therapy. In this review, we delve into some of the differences that notably distinguish HIV-2 from HIV-1, highlighting possible consequences in the pathogenesis and natural history of both infections.

  2. Modeling of interaction between a three-fingered surgical grasper and human spleen.

    PubMed

    Tirehdast, Mojdeh; Mirbagheri, Alireza; Asghari, Mohsen; Farahmand, Farzam

    2011-01-01

    The aim of this study was to develop a more sophisticated model of the spleen tissue and investigate its interactions with a three-fingered laparoscopic grasper. The spleen tissue, modeled as a hyper viscoelastic material, was subjected to external loadings, imposed by rigid grasping jaws. The tissue deformation as well as the sliding occurrence between tissue and jaws was investigated using nonlinear finite element method. Results indicated that a grasping configuration which aimed a sufficiently large piece of spleen with small radius of curvature was more successful for effective grasping. The trends and magnitudes of the tool-tissue interaction forces obtained during effective and ineffective grasping were quite different. A force with progressively increasing trend toward a high magnitude was found to be indicative of effective and safe grasping. This finding might be used to predict the effectiveness of different grasping configurations and sliding thresholds during spleen and other soft organs surgery.

  3. Probing the binding interaction of AKR with human serum albumin by multiple fluorescence spectroscopy and molecular modeling.

    PubMed

    Li, Yan; Chen, Chun; Zhang, Chunping; Duan, Jingyu; Yao, Huankai; Wei, Qunli

    2017-05-01

    Human serum albumin (HSA) is the major transport protein affording endogenous and exogenous substances in plasma. It can affect the behavior and efficacy of chemicals in vivo through the binding interaction. AKR (3-O-α-l-arabinofuranosyl-kaempferol-7-O-α-l-rhamnopyranoside) is a flavonoid diglycoside with modulation of estrogen receptors (ERs). Herein, we investigated the binding interaction between AKR and HSA by multiple fluorescence spectroscopy and molecular modeling. As a result, AKR specifically binds in site I of HSA through hydrogen bonds, van der Waals force, and electrostatic interaction. The formation of AKR-HSA complex in binding process is spontaneously exothermic and leads to the static fluorescence quenching through affecting the microenvironment around the fluorophores. The complex also affects the backbone of HSA and makes AKR access to fluorophores. Molecular modeling gives the visualization of the interaction between AKR and HSA as well as ERs. The affinity of AKR with HSA is higher than the competitive site marker Warfarin. In addition, docking studies reveal the binding interaction of AKR with ERs through hydrogen bonds, van der Waals force, hydrophobic, and electrostatic interactions. And AKR is more favorable to ERβ. These results unravel the binding interaction of AKR with HSA and mechanism as an ERs modulator.

  4. Probing the molecular interaction of triazole fungicides with human serum albumin by multispectroscopic techniques and molecular modeling.

    PubMed

    Zhang, Jing; Zhuang, Shulin; Tong, Changlun; Liu, Weiping

    2013-07-31

    Triazole fungicides, one category of broad-spectrum fungicides, are widely applied in agriculture and medicine. The extensive use leads to many residues and casts potential detrimental effects on aquatic ecosystems and human health. After exposure of the human body, triazole fungicides may penetrate into the bloodstream and interact with plasma proteins. Whether they could have an impact on the structure and function of proteins is still poorly understood. By using multispectroscopic techniques and molecular modeling, the interaction of several typical triazole fungicides with human serum albumin (HSA), the major plasma protein, was investigated. The steady-state and time-resolved fluorescence spectra manifested that static type, due to complex formation, was the dominant mechanism for fluorescence quenching. Structurally related binding modes speculated by thermodynamic parameters agreed with the prediction of molecular modeling. For triadimefon, hydrogen bonding with Arg-218 and Arg-222 played an important role, whereas for imazalil, myclobutanil, and penconazole, the binding process was mainly contributed by hydrophobic and electrostatic interactions. Via alterations in three-dimensional fluorescence and circular dichroism spectral properties, it was concluded that triazoles could induce slight conformational and some microenvironmental changes of HSA. It is anticipated that these data can provide some information for possible toxicity risk of triazole fungicides to human health and be helpful in reinforcing the supervision of food safety.

  5. Cognitive Model of Trust Dynamics Predicts Human Behavior within and between Two Games of Strategic Interaction with Computerized Confederate Agents

    PubMed Central

    Collins, Michael G.; Juvina, Ion; Gluck, Kevin A.

    2016-01-01

    When playing games of strategic interaction, such as iterated Prisoner's Dilemma and iterated Chicken Game, people exhibit specific within-game learning (e.g., learning a game's optimal outcome) as well as transfer of learning between games (e.g., a game's optimal outcome occurring at a higher proportion when played after another game). The reciprocal trust players develop during the first game is thought to mediate transfer of learning effects. Recently, a computational cognitive model using a novel trust mechanism has been shown to account for human behavior in both games, including the transfer between games. We present the results of a study in which we evaluate the model's a priori predictions of human learning and transfer in 16 different conditions. The model's predictive validity is compared against five model variants that lacked a trust mechanism. The results suggest that a trust mechanism is necessary to explain human behavior across multiple conditions, even when a human plays against a non-human agent. The addition of a trust mechanism to the other learning mechanisms within the cognitive architecture, such as sequence learning, instance-based learning, and utility learning, leads to better prediction of the empirical data. It is argued that computational cognitive modeling is a useful tool for studying trust development, calibration, and repair. PMID:26903892

  6. Cognitive Model of Trust Dynamics Predicts Human Behavior within and between Two Games of Strategic Interaction with Computerized Confederate Agents.

    PubMed

    Collins, Michael G; Juvina, Ion; Gluck, Kevin A

    2016-01-01

    When playing games of strategic interaction, such as iterated Prisoner's Dilemma and iterated Chicken Game, people exhibit specific within-game learning (e.g., learning a game's optimal outcome) as well as transfer of learning between games (e.g., a game's optimal outcome occurring at a higher proportion when played after another game). The reciprocal trust players develop during the first game is thought to mediate transfer of learning effects. Recently, a computational cognitive model using a novel trust mechanism has been shown to account for human behavior in both games, including the transfer between games. We present the results of a study in which we evaluate the model's a priori predictions of human learning and transfer in 16 different conditions. The model's predictive validity is compared against five model variants that lacked a trust mechanism. The results suggest that a trust mechanism is necessary to explain human behavior across multiple conditions, even when a human plays against a non-human agent. The addition of a trust mechanism to the other learning mechanisms within the cognitive architecture, such as sequence learning, instance-based learning, and utility learning, leads to better prediction of the empirical data. It is argued that computational cognitive modeling is a useful tool for studying trust development, calibration, and repair.

  7. Validation and Application of COGNET Model of Human-Computer Interaction in Naval Air ASW

    DTIC Science & Technology

    1990-05-31

    cyclically, but this produced side effects which could not be controlled in a straightforward manner. The immediate problem was solved by checking the triggers...design of more effective human-computer interfaces. This research developed the COGNET (COGnitive Network of Tasks) RTMT modeling framework, as an...Accomplished by Interface .................... 5-26 Figure 5-17. Build Tritac Subgoal Accomplished by Intorface ............................... 5-27 III

  8. A structural model for the in vivo human cornea including collagen-swelling interaction

    PubMed Central

    Cheng, Xi; Petsche, Steven J.; Pinsky, Peter M.

    2015-01-01

    A structural model of the in vivo cornea, which accounts for tissue swelling behaviour, for the three-dimensional organization of stromal fibres and for collagen-swelling interaction, is proposed. Modelled as a binary electrolyte gel in thermodynamic equilibrium, the stromal electrostatic free energy is based on the mean-field approximation. To account for active endothelial ionic transport in the in vivo cornea, which modulates osmotic pressure and hydration, stromal mobile ions are shown to satisfy a modified Boltzmann distribution. The elasticity of the stromal collagen network is modelled based on three-dimensional collagen orientation probability distributions for every point in the stroma obtained by synthesizing X-ray diffraction data for azimuthal angle distributions and second harmonic-generated image processing for inclination angle distributions. The model is implemented in a finite-element framework and employed to predict free and confined swelling of stroma in an ionic bath. For the in vivo cornea, the model is used to predict corneal swelling due to increasing intraocular pressure (IOP) and is adapted to model swelling in Fuchs' corneal dystrophy. The biomechanical response of the in vivo cornea to a typical LASIK surgery for myopia is analysed, including tissue fluid pressure and swelling responses. The model provides a new interpretation of the corneal active hydration control (pump-leak) mechanism based on osmotic pressure modulation. The results also illustrate the structural necessity of fibre inclination in stabilizing the corneal refractive surface with respect to changes in tissue hydration and IOP. PMID:26156299

  9. Building a Formal Model of a Human-Interactive System: Insights into the Integration of Formal Methods and Human Factors Engineering

    NASA Technical Reports Server (NTRS)

    Bolton, Matthew L.; Bass, Ellen J.

    2009-01-01

    Both the human factors engineering (HFE) and formal methods communities are concerned with finding and eliminating problems with safety-critical systems. This work discusses a modeling effort that leveraged methods from both fields to use model checking with HFE practices to perform formal verification of a human-interactive system. Despite the use of a seemingly simple target system, a patient controlled analgesia pump, the initial model proved to be difficult for the model checker to verify in a reasonable amount of time. This resulted in a number of model revisions that affected the HFE architectural, representativeness, and understandability goals of the effort. If formal methods are to meet the needs of the HFE community, additional modeling tools and technological developments are necessary.

  10. Investigation of interaction of antibacterial drug sulfamethoxazole with human serum albumin by molecular modeling and multi-spectroscopic method.

    PubMed

    Wang, Qin; Zhang, Sheng-Rui; Ji, Xiaohui

    2014-04-24

    Interaction of sulfamethoxazole (SMX) with human serum albumin (HSA) was investigated by molecular modeling and multi-spectroscopic methods under physiological conditions. The interaction mechanism was firstly predicted through molecular modeling that confirmed the interaction between SMX and HSA. The binding parameters and the thermodynamic parameters at different temperatures for the reaction had been calculated according to the Stern-Volmer, Hill, Scatchard and the Van't Hoff equations, respectively. One independent class of binding site existed during the interaction between HSA and SMX. The binding constants decreased with the increasing temperatures, which meant that the quenching mechanism was a static quenching. The thermodynamic parameters of the reaction, namely standard enthalpy ΔH(0) and entropy ΔS(0), had been calculated to be -16.40 kJ mol(-1) and 32.33 J mol(-1) K(-1), respectively, which suggested that the binding process was exothermic, enthalpy driven and spontaneous. SMX bound to HSA was mainly based on electrostatic interaction, but hydrophobic interactions and hydrogen bonds could not be excluded from the binding. The conformational changes of HSA in the presence of SMX were confirmed by the three-dimensional fluorescence spectroscopy, UV-vis absorption spectroscopy and circular dichroism (CD) spectroscopy. CD data suggested that the protein conformation was altered with the reduction of α-helices from 55.37% to 41.97% at molar ratio of SMX/HSA of 4:1.

  11. Modelling the interaction of electromagnetic fields (10 MHz-10 GHz) with the human body: methods and applications.

    PubMed

    Hand, J W

    2008-08-21

    Numerical modelling of the interaction between electromagnetic fields (EMFs) and the dielectrically inhomogeneous human body provides a unique way of assessing the resulting spatial distributions of internal electric fields, currents and rate of energy deposition. Knowledge of these parameters is of importance in understanding such interactions and is a prerequisite when assessing EMF exposure or when assessing or optimizing therapeutic or diagnostic medical applications that employ EMFs. In this review, computational methods that provide this information through full time-dependent solutions of Maxwell's equations are summarized briefly. This is followed by an overview of safety- and medical-related applications where modelling has contributed significantly to development and understanding of the techniques involved. In particular, applications in the areas of mobile communications, magnetic resonance imaging, hyperthermal therapy and microwave radiometry are highlighted. Finally, examples of modelling the potentially new medical applications of recent technologies such as ultra-wideband microwaves are discussed.

  12. TOPICAL REVIEW: Modelling the interaction of electromagnetic fields (10 MHz 10 GHz) with the human body: methods and applications

    NASA Astrophysics Data System (ADS)

    Hand, J. W.

    2008-08-01

    Numerical modelling of the interaction between electromagnetic fields (EMFs) and the dielectrically inhomogeneous human body provides a unique way of assessing the resulting spatial distributions of internal electric fields, currents and rate of energy deposition. Knowledge of these parameters is of importance in understanding such interactions and is a prerequisite when assessing EMF exposure or when assessing or optimizing therapeutic or diagnostic medical applications that employ EMFs. In this review, computational methods that provide this information through full time-dependent solutions of Maxwell's equations are summarized briefly. This is followed by an overview of safety- and medical-related applications where modelling has contributed significantly to development and understanding of the techniques involved. In particular, applications in the areas of mobile communications, magnetic resonance imaging, hyperthermal therapy and microwave radiometry are highlighted. Finally, examples of modelling the potentially new medical applications of recent technologies such as ultra-wideband microwaves are discussed.

  13. Highly Differentiated Human Airway Epithelial Cells: a Model to Study Host cell-parasite Interactions in Pertussis

    PubMed Central

    Guevara, Claudia; Zhang, Chengxian; Gaddy, Jennifer A.; Iqbal, Junaid; Guerra, Julio; Greenberg, David P.; Decker, Michael D.; Carbonetti, Nicholas; Starner, Timothy D.; McCray, Paul B.; Mooi, Frits R.

    2017-01-01

    Background Bordetella pertussis colonizes the human respiratory mucosa. Most studies on B. pertussis adherence have relied on cultured mammalian cells that lack key features present in differentiated human airway cells or on animal models that are not natural hosts of B. pertussis. The objectives of this work are to evaluate B. pertussis infection on highly differentiated human airway cells in vitro and to show the role of B. pertussis fimbriae in cell adherence. Methods Primary human airway epithelial (PHAE) cells from human bronchi and a human bronchial epithelial (HBE) cell line were grown in vitro under air-liquid interface conditions. Results PHAE and HBE cells infected with B. pertussis wild type strain revealed bacterial adherence to cell’s apical surface and bacterial induced cytoskeleton changes and cell detachment. Mutations in the major fimbrial subunits Fim2/3 or in the minor fimbrial adhesin subunit FimD affected B. pertussis adherence to predominantly HBE cells. This cell model recapitulates the morphologic features of the human airway infected by B. pertussis and confirms the role of fimbriae in B. pertussis adherence. Furthemore, HBE cells show that fimbrial subunits, and specifically FimD adhesin, are critical in B. pertussis adherence to airway cells. Conclusions The relevance of this model to study host-parasite interaction in pertussis lies in the striking physiologic and morphologic similarity between the PHAE and HBE cells and the human airway ciliated and goblet cells in vivo. These cells can proliferate in vitro, differentiate, and express the same genetic profile as human respiratory cells in vivo. PMID:26492208

  14. CD4-gp120 interaction interface - a gateway for HIV-1 infection in human: molecular network, modeling and docking studies.

    PubMed

    Pandey, Deeksha; Podder, Avijit; Pandit, Mansi; Latha, Narayanan

    2017-09-01

    The major causative agent for Acquired Immune Deficiency Syndrome (AIDS) is Human Immunodeficiency Virus-1 (HIV-1). HIV-1 is a predominant subtype of HIV which counts on human cellular mechanism virtually in every aspect of its life cycle. Binding of viral envelope glycoprotein-gp120 with human cell surface CD4 receptor triggers the early infection stage of HIV-1. This study focuses on the interaction interface between these two proteins that play a crucial role for viral infectivity. The CD4-gp120 interaction interface has been studied through a comprehensive protein-protein interaction network (PPIN) analysis and highlighted as a useful step towards identifying potential therapeutic drug targets against HIV-1 infection. We prioritized gp41, Nef and Tat proteins of HIV-1 as valuable drug targets at early stage of viral infection. Lack of crystal structure has made it difficult to understand the biological implication of these proteins during disease progression. Here, computational protein modeling techniques and molecular dynamics simulations were performed to generate three-dimensional models of these targets. Besides, molecular docking was initiated to determine the desirability of these target proteins for already available HIV-1 specific drugs which indicates the usefulness of these protein structures to identify an effective drug combination therapy against AIDS.

  15. Synergistic Interactions between Drosophila Orthologues of Genes Spanned by De Novo Human CNVs Support Multiple-Hit Models of Autism

    PubMed Central

    Grice, Stuart J.; Liu, Ji-Long; Webber, Caleb

    2015-01-01

    Autism spectrum disorders (ASDs) are highly heritable and characterised by deficits in social interaction and communication, as well as restricted and repetitive behaviours. Although a number of highly penetrant ASD gene variants have been identified, there is growing evidence to support a causal role for combinatorial effects arising from the contributions of multiple loci. By examining synaptic and circadian neurological phenotypes resulting from the dosage variants of unique human:fly orthologues in Drosophila, we observe numerous synergistic interactions between pairs of informatically-identified candidate genes whose orthologues are jointly affected by large de novo copy number variants (CNVs). These CNVs were found in the genomes of individuals with autism, including a patient carrying a 22q11.2 deletion. We first demonstrate that dosage alterations of the unique Drosophila orthologues of candidate genes from de novo CNVs that harbour only a single candidate gene display neurological defects similar to those previously reported in Drosophila models of ASD-associated variants. We then considered pairwise dosage changes within the set of orthologues of candidate genes that were affected by the same single human de novo CNV. For three of four CNVs with complete orthologous relationships, we observed significant synergistic effects following the simultaneous dosage change of gene pairs drawn from a single CNV. The phenotypic variation observed at the Drosophila synapse that results from these interacting genetic variants supports a concordant phenotypic outcome across all interacting gene pairs following the direction of human gene copy number change. We observe both specificity and transitivity between interactors, both within and between CNV candidate gene sets, supporting shared and distinct genetic aetiologies. We then show that different interactions affect divergent synaptic processes, demonstrating distinct molecular aetiologies. Our study illustrates

  16. A primary human macrophage-enteroid co-culture model to investigate mucosal gut physiology and host-pathogen interactions

    PubMed Central

    Noel, Gaelle; Baetz, Nicholas W.; Staab, Janet F.; Donowitz, Mark; Kovbasnjuk, Olga; Pasetti, Marcela F.; Zachos, Nicholas C.

    2017-01-01

    Integration of the intestinal epithelium and the mucosal immune system is critical for gut homeostasis. The intestinal epithelium is a functional barrier that secludes luminal content, senses changes in the gut microenvironment, and releases immune regulators that signal underlying immune cells. However, interactions between epithelial and innate immune cells to maintain barrier integrity and prevent infection are complex and poorly understood. We developed and characterized a primary human macrophage-enteroid co-culture model for in-depth studies of epithelial and macrophage interactions. Human intestinal stem cell-derived enteroid monolayers co-cultured with human monocyte-derived macrophages were used to evaluate barrier function, cytokine secretion, and protein expression under basal conditions and following bacterial infection. Macrophages enhanced barrier function and maturity of enteroid monolayers as indicated by increased transepithelial electrical resistance and cell height. Communication between the epithelium and macrophages was demonstrated through morphological changes and cytokine production. Intraepithelial macrophage projections, efficient phagocytosis, and stabilized enteroid barrier function revealed a coordinated response to enterotoxigenic and enteropathogenic E. coli infections. In summary, we have established the first primary human macrophage-enteroid co-culture system, defined conditions that allow for a practical and reproducible culture model, and demonstrated its suitability to study gut physiology and host responses to enteric pathogens. PMID:28345602

  17. Modeling boyciana-fish-human interaction with partial differential algebraic equations.

    PubMed

    Jiang, Yushan; Zhang, Qingling; Wang, Haiyan

    2016-07-01

    Under the influence of human population distribution, the boyciana-fish ecological system is considered. First, the system can be described as a nonlinear partial differential algebraic equations system (PDAEs) with Neumann boundary conditions and ratio-dependent functional response. Second, we examine the system's persistence properties: the loacl stabilities of positive steady states, the absorbtion region and the global stability. And the proposed approach is illustrated by numerical simulation. Finally, by using the realistic data collected in the past fourteen years, the PDAEs parameter optimization model is built to predict the boyciana population.

  18. Chemical synthesis of two series of nerve agent model compounds and their stereoselective interaction with human acetylcholinesterase and human butyrylcholinesterase.

    PubMed

    Barakat, Nora H; Zheng, Xueying; Gilley, Cynthia B; MacDonald, Mary; Okolotowicz, Karl; Cashman, John R; Vyas, Shubham; Beck, Jeremy M; Hadad, Christopher M; Zhang, Jun

    2009-10-01

    Both G and V type nerve agents possess a center of chirality about phosphorus. The S(p) enantiomers are generally more potent inhibitors than their R(p) counterparts toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). To develop model compounds with defined centers of chirality that mimic the target nerve agent structures, we synthesized both the S(p) and the R(p) stereoisomers of two series of G type nerve agent model compounds in enantiomerically enriched form. The two series of model compounds contained identical substituents on the phosphorus as the G type agents, except that thiomethyl (CH(3)-S-) and thiocholine [(CH(3))(3)NCH(2)CH(2)-S-] groups were used to replace the traditional nerve agent leaving groups (i.e., fluoro for GB, GF, and GD and cyano for GA). Inhibition kinetic studies of the thiomethyl- and thiocholine-substituted series of nerve agent model compounds revealed that the S(p) enantiomers of both series of compounds showed greater inhibition potency toward AChE and BChE. The level of stereoselectivity, as indicated by the ratio of the bimolecular inhibition rate constants between S(p) and R(p) enantiomers, was greatest for the GF model compounds in both series. The thiocholine analogues were much more potent than the corresponding thiomethyl analogues. With the exception of the GA model compounds, both series showed greater potency against AChE than BChE. The stereoselectivity (i.e., S(p) > R(p)), enzyme selectivity, and dynamic range of inhibition potency contributed from these two series of compounds suggest that the combined application of these model compounds will provide useful research tools for understanding interactions of nerve agents with cholinesterase and other enzymes involved in nerve agent and organophosphate pharmacology. The potential of and limitations for using these model compounds in the development of biological therapeutics against nerve agent toxicity are also discussed.

  19. Linking Spatial Structure and Community-Level Biotic Interactions through Cooccurrence and Time Series Modeling of the Human Intestinal Microbiota.

    PubMed

    de Muinck, Eric J; Lundin, Knut E A; Trosvik, Pål

    2017-01-01

    The gastrointestinal (GI) microbiome is a densely populated ecosystem where dynamics are determined by interactions between microbial community members, as well as host factors. The spatial organization of this system is thought to be important in human health, yet this aspect of our resident microbiome is still poorly understood. In this study, we report significant spatial structure of the GI microbiota, and we identify general categories of spatial patterning in the distribution of microbial taxa along a healthy human GI tract. We further estimate the biotic interaction structure in the GI microbiota, both through time series and cooccurrence modeling of microbial community data derived from a large number of sequentially collected fecal samples. Comparison of these two approaches showed that species pairs involved in significant negative interactions had strong positive contemporaneous correlations and vice versa, while for species pairs without significant interactions, contemporaneous correlations were distributed around zero. We observed similar patterns when comparing these models to the spatial correlations between taxa identified in the adherent microbiota. This suggests that colocalization of microbial taxon pairs, and thus the spatial organization of the GI microbiota, is driven, at least in part, by direct or indirect biotic interactions. Thus, our study can provide a basis for an ecological interpretation of the biogeography of the human gut. IMPORTANCE The human gut microbiome is the subject of intense study due to its importance in health and disease. The majority of these studies have been based on the analysis of feces. However, little is known about how the microbial composition in fecal samples relates to the spatial distribution of microbial taxa along the gastrointestinal tract. By characterizing the microbial content both in intestinal tissue samples and in fecal samples obtained daily, we provide a conceptual framework for how the spatial

  20. Molecular modeling and multi-spectroscopic approaches to study the interaction between antibacterial drug and human immunoglobulin G.

    PubMed

    Wang, Qin; Min, Suotian; Liu, Zhifeng; Zhang, Shengrui

    2016-05-01

    Mechanistic and conformational studies on the interaction of sulfamethoxazole (SMX) with human immunoglobulin G (HIgG) were performed by molecular modeling and multi-spectroscopic methods. The interaction mechanism was firstly predicted through molecular modeling that confirmed the interaction between SMX and HIgG. The binding parameters and thermodynamic parameters at different temperatures had been calculated according to the Stern-Volmer, Scatchard, Sips and Van 't Hoff equations, respectively. Experimental results showed that the fluorescence intensity of HIgG was quenched by the gradual addition of SMX. The binding constants of SMX with HIgG decreased with the increase of temperature, which meant that the quenching mechanism was a static quenching. Meanwhile, the results also confirmed that there was one independent class of binding site on HIgG for SMX during their interaction. The thermodynamic parameters of the reaction, namely standard enthalpy ΔH(0) and entropy ΔS(0), had been calculated to be -14.69 kJ·mol(-1) and 22.99 J·mol(-1) ·K(-1), respectively, which suggested that the electrostatic and hydrophobic interactions were the predominant intermolecular forces in stabilizing the SMX-HIgG complex. Furthermore, experimental results obtained from three-dimensional fluorescence spectroscopy, UV-vis absorption spectroscopy and circular dichroism (CD) spectroscopy confirmed that the conformational structure of HIgG was altered in the presence of SMX.

  1. Quantitative modeling of human-environment interactions in the preindustrial world

    NASA Astrophysics Data System (ADS)

    Kaplan, J. O.; Sommer, P.; Kay, A. U.; Phelps, L. N.

    2016-12-01

    Over the past 10,000 years, a series of agricultural and technological developments revolutionized land use by societies on most continents. The spread of crop plants, the use of fire for land management, the adoption of animal traction, the invention of the plow and the wheel, of metal agricultural implements, and the application of organic fertilizers all led to the intensification agricultural land use. This intensification allowed both growing human populations to be supported by a stable land base, and opened up new frontiers for agriculture that were previously undesirable for cultivation. In some cases, growing populations further developed macro-levels of social organization that facilitated collective undertakings that influenced land use, such as irrigation and terracing. All of these phenomena occurred heterogeneously in space and time, and their importance for anthropogenic land cover change over the Holocene is strongly debated. Here we quantify human influence on global landscapes using a numerical model describing preindustrial agriculture. The model is driven by archaeological information describing agriculture, technology, and social organization, and with environmental constraints from climate and soils. We simulate the environmental impact of changing land use systems over the early agricultural era. At least since the 3000 BP, agricultural land use is substantial enough to have had a significant impact on the distribution of forests and wetlands across large parts of Eurasia, Africa, and the Americas.

  2. Phoneme restoration and empirical coverage of interactive activation and adaptive resonance models of human speech processing.

    PubMed

    Magnuson, James S

    2015-03-01

    Grossberg and Kazerounian [(2011). J. Acoust. Soc. Am. 130, 440-460] present a model of sequence representation for spoken word recognition, the cARTWORD model, which simulates essential aspects of phoneme restoration. Grossberg and Kazerounian also include simulations with the TRACE model presented by McClelland and Elman [(1986). Cognit. Psychol. 18, 1-86] that seem to indicate that TRACE cannot simulate phoneme restoration. Grossberg and Kazerounian also claim cARTWORD should be preferred to TRACE because of TRACE's implausible approach to sequence representation (reduplication of time-specific units) and use of non-modulatory feedback (i.e., without position-specific bottom-up support). This paper responds to Grossberg and Kazerounian first with TRACE simulations that account for phoneme restoration when appropriately constructed noise is used (and with minor changes to TRACE phoneme definitions), then reviews the case for reduplicated units and feedback as implemented in TRACE, as well as TRACE's broad and deep coverage of empirical data. Finally, it is argued that cARTWORD is not comparable to TRACE because cARTWORD cannot represent sequences with repeated elements, has only been implemented with small phoneme and lexical inventories, and has been applied to only one phenomenon (phoneme restoration). Without evidence that cARTWORD captures a similar range and detail of human spoken language processing as alternative models, it is premature to prefer cARTWORD to TRACE.

  3. Phoneme restoration and empirical coverage of interactive activation and adaptive resonance models of human speech processing

    PubMed Central

    Magnuson, James S.

    2015-01-01

    Grossberg and Kazerounian [(2011). J. Acoust. Soc. Am. 130, 440–460] present a model of sequence representation for spoken word recognition, the cARTWORD model, which simulates essential aspects of phoneme restoration. Grossberg and Kazerounian also include simulations with the TRACE model presented by McClelland and Elman [(1986). Cognit. Psychol. 18, 1–86] that seem to indicate that TRACE cannot simulate phoneme restoration. Grossberg and Kazerounian also claim cARTWORD should be preferred to TRACE because of TRACE's implausible approach to sequence representation (reduplication of time-specific units) and use of non-modulatory feedback (i.e., without position-specific bottom-up support). This paper responds to Grossberg and Kazerounian first with TRACE simulations that account for phoneme restoration when appropriately constructed noise is used (and with minor changes to TRACE phoneme definitions), then reviews the case for reduplicated units and feedback as implemented in TRACE, as well as TRACE's broad and deep coverage of empirical data. Finally, it is argued that cARTWORD is not comparable to TRACE because cARTWORD cannot represent sequences with repeated elements, has only been implemented with small phoneme and lexical inventories, and has been applied to only one phenomenon (phoneme restoration). Without evidence that cARTWORD captures a similar range and detail of human spoken language processing as alternative models, it is premature to prefer cARTWORD to TRACE. PMID:25786959

  4. Natural Human-Computer Interaction

    NASA Astrophysics Data System (ADS)

    D'Amico, Gianpaolo; Del Bimbo, Alberto; Dini, Fabrizio; Landucci, Lea; Torpei, Nicola

    Research work in relation to Natural Human-Computer Interaction concerns the theorization and development of systems that understand and recognize human communicative actions in order to engage people in a dialogue between them and their surroundings.

  5. Cognitive engineering models: A prerequisite to the design of human-computer interaction in complex dynamic systems

    NASA Technical Reports Server (NTRS)

    Mitchell, Christine M.

    1993-01-01

    This chapter examines a class of human-computer interaction applications, specifically the design of human-computer interaction for the operators of complex systems. Such systems include space systems (e.g., manned systems such as the Shuttle or space station, and unmanned systems such as NASA scientific satellites), aviation systems (e.g., the flight deck of 'glass cockpit' airplanes or air traffic control) and industrial systems (e.g., power plants, telephone networks, and sophisticated, e.g., 'lights out,' manufacturing facilities). The main body of human-computer interaction (HCI) research complements but does not directly address the primary issues involved in human-computer interaction design for operators of complex systems. Interfaces to complex systems are somewhat special. The 'user' in such systems - i.e., the human operator responsible for safe and effective system operation - is highly skilled, someone who in human-machine systems engineering is sometimes characterized as 'well trained, well motivated'. The 'job' or task context is paramount and, thus, human-computer interaction is subordinate to human job interaction. The design of human interaction with complex systems, i.e., the design of human job interaction, is sometimes called cognitive engineering.

  6. The interaction of 2-mercaptobenzimidazole with human serum albumin as determined by spectroscopy, atomic force microscopy and molecular modeling.

    PubMed

    Li, Yuqin; Jia, Baoxiu; Wang, Hao; Li, Nana; Chen, Gaopan; Lin, Yuejuan; Gao, Wenhua

    2013-04-01

    The interaction of 2-mercaptobenzimidazole (MBI) with human serum albumin (HSA) was studied in vitro by equilibrium dialysis under normal physiological conditions. This study used fluorescence, ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FT-IR), circular dichroism (CD) and Raman spectroscopy, atomic force microscopy (AFM) and molecular modeling techniques. Association constants, the number of binding sites and basic thermodynamic parameters were used to investigate the quenching mechanism. Based on the fluorescence resonance energy transfer, the distance between the HSA and MBI was 2.495 nm. The ΔG(0), ΔH(0), and ΔS(0) values across temperature indicated that the hydrophobic interaction was the predominant binding Force. The UV, FT-IR, CD and Raman spectra confirmed that the HSA secondary structure was altered in the presence of MBI. In addition, the molecular modeling showed that the MBI-HSA complex was stabilized by hydrophobic forces, which resulted from amino acid residues. The AFM results revealed that the individual HSA molecule dimensions were larger after interaction with MBI. Overall, this study suggested a method for characterizing the weak intermolecular interaction. In addition, this method is potentially useful for elucidating the toxigenicity of MBI when it is combined with the biomolecular function effect, transmembrane transport, toxicological testing and other experiments.

  7. Modeling for planetary boundaries: a network analysis of representations of complex human-environmental interactions in integrated global models

    NASA Astrophysics Data System (ADS)

    Friedrich, Johannes; Fetzer, Ingo; Cornell, Sarah

    2016-04-01

    The planetary boundaries framework is an approach to global sustainability that emphasises non-linear threshold behavior in anthropogenically perturbed Earth system processes. However, knowledge about the characteristics and positions of thresholds, and the scope for management of the boundaries is not well established. Global integrated models can help to improve this understanding, by reflecting the complex feedbacks between human and environmental systems. This study analyses the current state of integrated models with regard to the main processes identified as 'critical Earth system processes' in the planetary boundaries framework, and identifies gaps and suggests priorities for future improvements. Our approach involves creating a common ontology of model descriptions, and performing a network analysis on the state of system integration in models. The distinct clusters of specific biophysical and social-economic systems obviously has enabled progress in those specific areas of global change, but it now constrains analysis of important human-driven Earth system dynamics. The modeling process therefore has to be improved through technical integration, scientific gap-filling, and also changes in scientific institutional dynamics. Combined, this can advance model potentials that may help us to find sustainable pathways within planetary boundaries.

  8. Ex vivo human skin and SZ95 sebocytes exhibit a homoeostatic interaction in a novel coculture contact model.

    PubMed

    Nikolakis, Georgios; Seltmann, Holger; Hossini, Amir M; Makrantonaki, Evgenia; Knolle, Jürgen; Zouboulis, Christos C

    2015-07-01

    The sebaceous gland displays key functions of the human skin, such as hormone synthesis in situ, antimicrobial activity and participation to inflammatory responses. Consequently, there is an emerging need of advanced in vitro models to study complex interactions between the sebaceous gland and the other skin compartments. Despite the evolution of both full-skin organ culture and reconstructed three-dimensional skin models, no satisfactory solutions have been provided for the integration of sebaceous glands and/or sebaceous gland cells in those models, probably due to their problematic maintenance both in vitro and ex vivo. We have developed a coculture model of explant skin in direct contact with immortalized SZ95 sebocytes, which resulted in overall improved structural integrity of the epidermis, higher percentage of proliferating basal epidermal cells and reduced apoptosis of differentiating keratinocytes after 6 days, as detected by Ki67 and TUNEL staining, respectively. Furthermore SZ95 sebocytes exhibited morphological and biochemical signs of normal differentiation and lipid accumulation, while interleukin-6 expression in the supernatant of the cocultures was decreased in comparison with the control. The data provide evidence of a beneficial interaction between sebocytes and skin explants and provide the rationale for their integration in future three-dimensional skin models.

  9. NAD+-Metabolizing Ectoenzymes in Remodeling Tumor–Host Interactions: The Human Myeloma Model

    PubMed Central

    Horenstein, Alberto L.; Chillemi, Antonella; Quarona, Valeria; Zito, Andrea; Roato, Ilaria; Morandi, Fabio; Marimpietri, Danilo; Bolzoni, Marina; Toscani, Denise; Oldham, Robert J.; Cuccioloni, Massimiliano; Sasser, A. Kate; Pistoia, Vito; Giuliani, Nicola; Malavasi, Fabio

    2015-01-01

    Nicotinamide adenine dinucleotide (NAD+) is an essential co-enzyme reported to operate both intra- and extracellularly. In the extracellular space, NAD+ can elicit signals by binding purinergic P2 receptors or it can serve as the substrate for a chain of ectoenzymes. As a substrate, it is converted to adenosine (ADO) and then taken up by the cells, where it is transformed and reincorporated into the intracellular nucleotide pool. Nucleotide-nucleoside conversion is regulated by membrane-bound ectoenzymes. CD38, the main mammalian enzyme that hydrolyzes NAD+, belongs to the ectoenzymatic network generating intracellular Ca2+-active metabolites. Within this general framework, the extracellular conversion of NAD+ can vary significantly according to the tissue environment or pathological conditions. Accumulating evidence suggests that tumor cells exploit such a network for migrating and homing to protected areas and, even more importantly, for evading the immune response. We report on the experience of this lab to exploit human multiple myeloma (MM), a neoplastic expansion of plasma cells, as a model to investigate these issues. MM cells express high levels of surface CD38 and grow in an environment prevalently represented by closed niches hosted in the bone marrow (BM). An original approach of this study derives from the recent use of the clinical availability of therapeutic anti-CD38 monoclonal antibodies (mAbs) in perturbing tumor viability and enzymatic functions in conditions mimicking what happens in vivo. PMID:26393653

  10. Why E-Business Must Evolve beyond Market Orientation: Applying Human Interaction Models to Computer-Mediated Corporate Communications.

    ERIC Educational Resources Information Center

    Johnston, Kevin McCullough

    2001-01-01

    Considers the design of corporate communications for electronic business and discusses the increasing importance of corporate interaction as companies work in virtual environments. Compares sociological and psychological theories of human interaction and relationship formation with organizational interaction theories of corporate relationship…

  11. Why E-Business Must Evolve beyond Market Orientation: Applying Human Interaction Models to Computer-Mediated Corporate Communications.

    ERIC Educational Resources Information Center

    Johnston, Kevin McCullough

    2001-01-01

    Considers the design of corporate communications for electronic business and discusses the increasing importance of corporate interaction as companies work in virtual environments. Compares sociological and psychological theories of human interaction and relationship formation with organizational interaction theories of corporate relationship…

  12. Investigation of the interaction between quercetin and human serum albumin by multiple spectra, electrochemical impedance spectra and molecular modeling.

    PubMed

    Dai, Jie; Zou, Ting; Wang, Li; Zhang, Yezhong; Liu, Yi

    2014-12-01

    Quercetin (Qu), a flavonoid compound, exists widely in the human diet and exhibits a variety of pharmacological activities. This work is aimed at studying the effect of Qu on the bioactive protein, human serum albumin (HSA) under simulated biophysical conditions. Multiple spectroscopic methods (including fluorescence and circular dichroism), electrochemical impedance spectra (EIS) and molecular modeling were employed to investigate the interaction between Qu and HSA. The fluorescence quenching and EIS experimental results showed that the fluorescence quenching of HSA was caused by formation of a Qu-HSA complex in the ground state, which belonged to the static quenching mechanism. Based on the calculated thermodynamic parameters, it concluded that the interaction was a spontaneous process and hydrogen bonds combined with van der Waal's forces played a major role in stabilizing the Qu-HSA complex. Molecular modeling results demonstrated that several amino acids participated in the binding process and the formed Qu-HSA complex was stabilized by H-bonding network at site I in sub-domain IIA, which was further confirmed by the site marker competitive experiments. The evidence from circular dichroism (CD) indicated that the secondary structure and microenvironment of HSA were changed. Alterations in the conformation of HSA were observed with a reduction in the amount of α helix from 59.9% (free HSA) to 56% (Qu-HSA complex), indicating a slight unfolding of the protein polypeptides.

  13. Human-computer interaction in multitask situations

    NASA Technical Reports Server (NTRS)

    Rouse, W. B.

    1977-01-01

    Human-computer interaction in multitask decisionmaking situations is considered, and it is proposed that humans and computers have overlapping responsibilities. Queueing theory is employed to model this dynamic approach to the allocation of responsibility between human and computer. Results of simulation experiments are used to illustrate the effects of several system variables including number of tasks, mean time between arrivals of action-evoking events, human-computer speed mismatch, probability of computer error, probability of human error, and the level of feedback between human and computer. Current experimental efforts are discussed and the practical issues involved in designing human-computer systems for multitask situations are considered.

  14. Human-computer interaction in multitask situations

    NASA Technical Reports Server (NTRS)

    Rouse, W. B.

    1977-01-01

    Human-computer interaction in multitask decisionmaking situations is considered, and it is proposed that humans and computers have overlapping responsibilities. Queueing theory is employed to model this dynamic approach to the allocation of responsibility between human and computer. Results of simulation experiments are used to illustrate the effects of several system variables including number of tasks, mean time between arrivals of action-evoking events, human-computer speed mismatch, probability of computer error, probability of human error, and the level of feedback between human and computer. Current experimental efforts are discussed and the practical issues involved in designing human-computer systems for multitask situations are considered.

  15. Interaction of an antiepileptic drug, lamotrigine with human serum albumin (HSA): Application of spectroscopic techniques and molecular modeling methods.

    PubMed

    Poureshghi, Fatemeh; Ghandforoushan, Parisa; Safarnejad, Azam; Soltani, Somaieh

    2017-01-01

    Lamotrigine (an epileptic drug) interaction with human serum albumin (HSA) was investigated by fluorescence, UV-Vis, FTIR, CD spectroscopic techniques, and molecular modeling methods. Binding constant (Kb) of 5.74×10(3) and number of binding site of 0.97 showed that there is a slight interaction between lamotrigine and HSA. Thermodynamic studies was constructed using the flourimetric titrations in three different temperatures and the resulted data used to calculate the parameters using Vant Hoff equation. Decreased Stern Volmer quenching constant by enhanced temperature revealed the static quenching mechanism. Negative standard enthalpy (ΔH) and standard entropy (ΔS) changes indicated that van der Waals interactions and hydrogen bonds were dominant forces which facilitate the binding of Lamotrigine to HSA, the results were confirmed by molecular docking studies which showed no hydrogen binding. The FRET studies showed that there is a possibility of energy transfer between Trp214 and lamotrigine. Also the binding of lamotrigine to HSA in the studied concentrations was not as much as many other drugs, but the secondary structure of the HSA was significantly changed following the interaction in a way that α-helix percentage was reduced from 67% to 57% after the addition of lamotrigine in the molar ratio of 4:1 to HSA. According to the docking studies, lamotrigine binds to IB site preferably.

  16. Interaction of human trophoblast cells with gland-like endometrial spheroids: a model system for trophoblast invasion.

    PubMed

    Buck, V U; Gellersen, B; Leube, R E; Classen-Linke, I

    2015-04-01

    Do maternal endometrial epithelial cell (EEC) differentiation and polarity impact the invasive capacity of extravillous trophoblast (EVT) cells during early human implantation? In a three dimensional (3D) confrontation co-culture the invasiveness of the human trophoblast cell line AC-1M88 was inversely correlated with the degree of differentiation and polarization of human endometrial adenocarcinoma cell spheroids. In a previous study desmosomal and adherens junction proteins were shown to spread from a subapically restricted lateral position to the entire lateral membrane in human glandular EECs during the implantation window of the menstrual cycle. Whether this change in EEC junction localization has an impact on the interaction of EVT cells with glandular EECs during early human implantation is not known. A new 3D cell culture system was developed in order to mimic early implantation events in humans. As a model for the invasion of endometrial glands by EVT cells, spheroids of three differently differentiated and polarized endometrial adenocarcinoma cell lines were confronted with an EVT cell line in co-culture experiments. Three human adenocarcinoma EEC lines were chosen for this study because of their differences in differentiation and polarization: HEC-1-A, which is well differentiated and highly polarized, Ishikawa, which is well differentiated and moderately polarized, and RL95-2, which is moderately differentiated and poorly polarized. When the cell lines were grown in reconstituted basement membrane, they formed gland-like, multicellular spheroids. The degree of polarization within the different EEC spheroids was assessed by 3D confocal immunofluorescence microscopy detecting the basal membrane protein integrin α6, the apical tight junction-associated protein ZO-1 and the desmosomal plaque protein desmoplakin 1/2 (Dsp). Cells of the human EVT cell line AC-1M88, which is a fusion cell line of primary EVT cells and choriocarcinoma-derived JEG-3 cells, were

  17. Molecular interaction study of flavonoid derivative 3d with human serum albumin using multispectroscopic and molecular modeling approach.

    PubMed

    Wei, Juntong; Jin, Feng; Wu, Qin; Jiang, Yuyang; Gao, Dan; Liu, Hongxia

    2014-08-01

    Human serum albumin (HSA) has been developed as a model protein to study drug-protein interaction. In the present work, the interaction between our synthesized flavonoid derivative 3d (possessing potent antitumor activity against HepG2 cells) and HSA was investigated using fluorescence spectroscopy, circular dichroism spectroscopy, UV-vis spectroscopy and molecular modeling approach. Fluorescence spectroscopy showed that the fluorescence of HSA can be quenched remarkably by 3d under physiological condition with a slight shift of maximum fluorescence emission bands from 360nm to 363nm. Calculated results from Stern-Volmer equation and modified Stern-Volmer equation indicated that the fluorescence was quenched by static quenching processing with association constant 5.26±0.04×10(4)L mol(-1) at 298K. After comprehensive consideration of the free energy change ΔG, enthalpy change ΔH and entropy change ΔS, electrostatic interactions were confirmed as the main factor that participate in stabilizing the 3d-HSA complex. Both dichroism spectroscopy and UV-vis spectroscopy indicated conformational change of HSA after binding to 3d. Moreover, the structure of HSA was loosened and the percentage of α-helix decreased with increasing concentration of 3d. Molecular modeling results demonstrated that 3d could bind to HSA well into subdomain IIA, which is related to its capability of deposition and delivery. Three cation-π interactions and three hydrogen bonds occurred between 3d and amino acid residuals ARG218, ARG222 and LYS199. In conclusion, flavonoid derivative 3d can bind to HSA with noncovalent bond in a relatively stable way, so it can be delivered by HSA in a circulatory system. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Rochlis-Zumbado, Jennifer; Sandor, Aniko; Ezer, Neta

    2012-01-01

    Risk of Inadequate Design of Human and Automation/Robotic Integration (HARI) is a new Human Research Program (HRP) risk. HRI is a research area that seeks to understand the complex relationship among variables that affect the way humans and robots work together to accomplish goals. The DRP addresses three major HRI study areas that will provide appropriate information for navigation guidance to a teleoperator of a robot system, and contribute to the closure of currently identified HRP gaps: (1) Overlays -- Use of overlays for teleoperation to augment the information available on the video feed (2) Camera views -- Type and arrangement of camera views for better task performance and awareness of surroundings (3) Command modalities -- Development of gesture and voice command vocabularies

  19. Interactions Between Anandamide and Corticotropin-Releasing Factor Signaling Modulate Human Amygdala Function and Risk for Anxiety Disorders: An Imaging Genetics Strategy for Modeling Molecular Interactions.

    PubMed

    Demers, Catherine H; Drabant Conley, Emily; Bogdan, Ryan; Hariri, Ahmad R

    2016-09-01

    Preclinical models reveal that stress-induced amygdala activity and impairment in fear extinction reflect reductions in anandamide driven by corticotropin-releasing factor receptor type 1 (CRF1) potentiation of the anandamide catabolic enzyme fatty acid amide hydrolase. Here, we provide clinical translation for the importance of these molecular interactions using an imaging genetics strategy to examine whether interactions between genetic polymorphisms associated with differential anandamide (FAAH rs324420) and CRF1 (CRHR1 rs110402) signaling modulate amygdala function and anxiety disorder diagnosis. Analyses revealed that individuals with a genetic background predicting relatively high anandamide and CRF1 signaling exhibited blunted basolateral amygdala habituation, which further mediated increased risk for anxiety disorders among these same individuals. The convergence of preclinical and clinical data suggests that interactions between anandamide and CRF1 represent a fundamental molecular mechanism regulating amygdala function and anxiety. Our results further highlight the potential of imaging genetics to powerfully translate complex preclinical findings to clinically meaningful human phenotypes. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. Structural model for the interaction of a designed Ankyrin Repeat Protein with the human epidermal growth factor receptor 2.

    PubMed

    Epa, V Chandana; Dolezal, Olan; Doughty, Larissa; Xiao, Xiaowen; Jost, Christian; Plückthun, Andreas; Adams, Timothy E

    2013-01-01

    Designed Ankyrin Repeat Proteins are a class of novel binding proteins that can be selected and evolved to bind to targets with high affinity and specificity. We are interested in the DARPin H10-2-G3, which has been evolved to bind with very high affinity to the human epidermal growth factor receptor 2 (HER2). HER2 is found to be over-expressed in 30% of breast cancers, and is the target for the FDA-approved therapeutic monoclonal antibodies trastuzumab and pertuzumab and small molecule tyrosine kinase inhibitors. Here, we use computational macromolecular docking, coupled with several interface metrics such as shape complementarity, interaction energy, and electrostatic complementarity, to model the structure of the complex between the DARPin H10-2-G3 and HER2. We analyzed the interface between the two proteins and then validated the structural model by showing that selected HER2 point mutations at the putative interface with H10-2-G3 reduce the affinity of binding up to 100-fold without affecting the binding of trastuzumab. Comparisons made with a subsequently solved X-ray crystal structure of the complex yielded a backbone atom root mean square deviation of 0.84-1.14 Ångstroms. The study presented here demonstrates the capability of the computational techniques of structural bioinformatics in generating useful structural models of protein-protein interactions.

  1. Structural Model for the Interaction of a Designed Ankyrin Repeat Protein with the Human Epidermal Growth Factor Receptor 2

    PubMed Central

    Epa, V. Chandana; Dolezal, Olan; Doughty, Larissa; Xiao, Xiaowen; Jost, Christian; Plückthun, Andreas; Adams, Timothy E.

    2013-01-01

    Designed Ankyrin Repeat Proteins are a class of novel binding proteins that can be selected and evolved to bind to targets with high affinity and specificity. We are interested in the DARPin H10-2-G3, which has been evolved to bind with very high affinity to the human epidermal growth factor receptor 2 (HER2). HER2 is found to be over-expressed in 30% of breast cancers, and is the target for the FDA-approved therapeutic monoclonal antibodies trastuzumab and pertuzumab and small molecule tyrosine kinase inhibitors. Here, we use computational macromolecular docking, coupled with several interface metrics such as shape complementarity, interaction energy, and electrostatic complementarity, to model the structure of the complex between the DARPin H10-2-G3 and HER2. We analyzed the interface between the two proteins and then validated the structural model by showing that selected HER2 point mutations at the putative interface with H10-2-G3 reduce the affinity of binding up to 100-fold without affecting the binding of trastuzumab. Comparisons made with a subsequently solved X-ray crystal structure of the complex yielded a backbone atom root mean square deviation of 0.84–1.14 Ångstroms. The study presented here demonstrates the capability of the computational techniques of structural bioinformatics in generating useful structural models of protein-protein interactions. PMID:23527120

  2. Dll3 and Notch1 genetic interactions model axial segmental and craniofacial malformations of human birth defects.

    PubMed

    Loomes, Kathleen M; Stevens, Stacey A; O'Brien, Megan L; Gonzalez, Dorian M; Ryan, Matthew J; Segalov, Michelle; Dormans, Nicholas J; Mimoto, Mizuho S; Gibson, Joshua D; Sewell, William; Schaffer, Alyssa A; Nah, Hyun-Duck; Rappaport, Eric F; Pratt, Stephen C; Dunwoodie, Sally L; Kusumi, Kenro

    2007-10-01

    Mutations in the Notch1 receptor and delta-like 3 (Dll3) ligand cause global disruptions in axial segmental patterning. Genetic interactions between members of the notch pathway have previously been shown to cause patterning defects not observed in single gene disruptions. We examined Dll3-Notch1 compound mouse mutants to screen for potential gene interactions. While mice heterozygous at either locus appeared normal, 30% of Dll3-Notch1 double heterozygous animals exhibited localized, segmental anomalies similar to human congenital vertebral defects. Unexpectedly, double heterozygous mice also displayed statistically significant reduction of mandibular height and decreased length of the [corrected] maxillary hard palate. Examination of somite-stage embryos and perinatal anatomy and histology did not reveal any organ defects, so we used microarray-based analysis of Dll3 and Notch1 mutant embryos to identify gene targets that may be involved in notch-regulated segmental or craniofacial development. Thus, Dll3-Notch1 double heterozygous mice model human congenital scoliosis and craniofacial disorders.

  3. Negative Human Interaction

    ERIC Educational Resources Information Center

    Brannan, John M.

    1972-01-01

    This study is an effort to examine man's most negative experiences as he perceives them. The results indicated that teachers were involved more often than any other person in the most negative experience reported. Improved human relations skills are clearly indicated for those in higher education as well as in public schools. (Author)

  4. Human pericyte-endothelial cell interactions in co-culture models mimicking the diabetic retinal microvascular environment.

    PubMed

    Tarallo, Sonia; Beltramo, Elena; Berrone, Elena; Porta, Massimo

    2012-12-01

    Pericytes regulate vascular tone, perfusion pressure and endothelial cell (EC) proliferation in capillaries. Thiamine and benfotiamine counteract high glucose-induced damage in vascular cells. We standardized two human retinal pericyte (HRP)/EC co-culture models to mimic the diabetic retinal microvascular environment. We aimed at evaluating the interactions between co-cultured HRP and EC in terms of proliferation/apoptosis and the possible protective role of thiamine and benfotiamine against high glucose-induced damage. EC and HRP were co-cultured in physiological glucose and stable or intermittent high glucose, with or without thiamine/benfotiamine. No-contact model: EC were plated on a porous membrane suspended into the medium and HRP on the bottom of the same well. Cell-to-cell contact model: EC and HRP were plated on the opposite sides of the same membrane. Proliferation (cell counts and DNA synthesis), apoptosis and tubule formation in Matrigel were assessed. In the no-contact model, stable high glucose reduced proliferation of co-cultured EC/HRP and EC alone and increased co-cultured EC/HRP apoptosis. In the contact model, both stable and intermittent high glucose reduced co-cultured EC/HRP proliferation and increased apoptosis. Stable high glucose had no effects on HRP in separate cultures. Both EC and HRP proliferated better when co-cultured. Thiamine and benfotiamine reversed high glucose-induced damage in all cases. HRP are sensitive to soluble factors released by EC when cultured in high glucose conditions, as suggested by conditioned media assays. In the Matrigel models, addition of thiamine and benfotiamine re-established the high glucose-damaged interactions between EC/HRP and stabilized microtubules.

  5. Investigation of the interaction between sophoricoside and human serum albumin by optical spectroscopy and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Tang, Jianghong; Lian, Ning; He, Xianghong; Zhang, Guohua

    2008-10-01

    The interaction of sophoricoside and human serum albumin (HSA) was investigated by UV-absorption, fluorescence spectroscopy and Fourier transform infrared (FT-IR) spectroscopy at simulative physiological pH with sophoricoside concentrations of 3.0 × 10 -6 to 2.3 × 10 -5 mol L -1. The experimental results suggested that the intrinsic fluorescence of HSA was quenched by addition of sophoricoside through static quenching mechanism. The interaction between sophoricoside and HSA was occurred via a single class of binding site. The binding constants at 290, 301, 310 and 318 K were 6.19 × 10 4, 4.69 × 10 4, 3.54 × 10 4, 3.11 × 10 4 L mol -1, respectively. In the presence of sophoricoside the protein secondary structure changed in aqueous solution. The standard enthalpy change (-19.44 kJ mol -1) and standard entropy change (24.71 J mol -1 K -1) of the binding reaction revealed that hydrophobic interaction was the predominant binding force. In addition, molecular modeling showed that sophoricoside was bound within the subdomain IIA of the HSA.

  6. Occupational stress in human computer interaction.

    PubMed

    Smith, M J; Conway, F T; Karsh, B T

    1999-04-01

    There have been a variety of research approaches that have examined the stress issues related to human computer interaction including laboratory studies, cross-sectional surveys, longitudinal case studies and intervention studies. A critical review of these studies indicates that there are important physiological, biochemical, somatic and psychological indicators of stress that are related to work activities where human computer interaction occurs. Many of the stressors of human computer interaction at work are similar to those stressors that have historically been observed in other automated jobs. These include high workload, high work pressure, diminished job control, inadequate employee training to use new technology, monotonous tasks, por supervisory relations, and fear for job security. New stressors have emerged that can be tied primarily to human computer interaction. These include technology breakdowns, technology slowdowns, and electronic performance monitoring. The effects of the stress of human computer interaction in the workplace are increased physiological arousal; somatic complaints, especially of the musculoskeletal system; mood disturbances, particularly anxiety, fear and anger; and diminished quality of working life, such as reduced job satisfaction. Interventions to reduce the stress of computer technology have included improved technology implementation approaches and increased employee participation in implementation. Recommendations for ways to reduce the stress of human computer interaction at work are presented. These include proper ergonomic conditions, increased organizational support, improved job content, proper workload to decrease work pressure, and enhanced opportunities for social support. A model approach to the design of human computer interaction at work that focuses on the system "balance" is proposed.

  7. Interaction of human apolipoprotein A-I with model membranes exhibiting lipid domains.

    PubMed

    Arnulphi, Cristina; Sánchez, Susana A; Tricerri, M Alejandra; Gratton, Enrico; Jonas, Ana

    2005-07-01

    Several mechanisms for cell cholesterol efflux have been proposed, including membrane microsolubilization, suggesting that the existence of specific domains could enhance the transfer of lipids to apolipoproteins. In this work isothermal titration calorimetry, circular dichroism spectroscopy, and two-photon microscopy are used to study the interaction of lipid-free apolipoprotein A-I (apoA-I) with small unilamellar vesicles (SUVs) of 1-palmitoyl, 2-oleoyl phosphatidylcholine (POPC) and sphingomyelin (SM), with and without cholesterol. Below 30 degrees C the calorimetric results show that apoA-I interaction with POPC/SM SUVs produces an exothermic reaction, characterized as nonclassical hydrophobic binding. The heat capacity change (DeltaCp degrees ) is small and positive, whereas it was larger and negative for pure POPC bilayers, in the absence of SM. Inclusion of cholesterol in the membranes induces changes in the observed thermodynamic pattern of binding and counteracts the formation of alpha-helices in the protein. Above 30 degrees C the reactions are endothermic. Giant unilamellar vesicles (GUVs) of identical composition to the SUVs, and two-photon fluorescence microscopy techniques, were utilized to further characterize the interaction. Fluorescence imaging of the GUVs indicates coexistence of lipid domains under 30 degrees C. Binding experiments and Laurdan generalized-polarization measurements suggest that there is no preferential binding of the labeled apoA-I to any particular domain. Changes in the content of alpha-helix, binding, and fluidity data are discussed in the framework of the thermodynamic parameters.

  8. Top-down systems biology integration of conditional prebiotic modulated transgenomic interactions in a humanized microbiome mouse model

    PubMed Central

    Martin, Francois-Pierre J; Wang, Yulan; Sprenger, Norbert; Yap, Ivan K S; Rezzi, Serge; Ramadan, Ziad; Peré-Trepat, Emma; Rochat, Florence; Cherbut, Christine; van Bladeren, Peter; Fay, Laurent B; Kochhar, Sunil; Lindon, John C; Holmes, Elaine; Nicholson, Jeremy K

    2008-01-01

    Gut microbiome–host metabolic interactions affect human health and can be modified by probiotic and prebiotic supplementation. Here, we have assessed the effects of consumption of a combination of probiotics (Lactobacillus paracasei or L. rhamnosus) and two galactosyl-oligosaccharide prebiotics on the symbiotic microbiome–mammalian supersystem using integrative metabolic profiling and modeling of multiple compartments in germ-free mice inoculated with a model of human baby microbiota. We have shown specific impacts of two prebiotics on the microbial populations of HBM mice when co-administered with two probiotics. We observed an increase in the populations of Bifidobacterium longum and B. breve, and a reduction in Clostridium perfringens, which were more marked when combining prebiotics with L. rhamnosus. In turn, these microbial effects were associated with modulation of a range of host metabolic pathways observed via changes in lipid profiles, gluconeogenesis, and amino-acid and methylamine metabolism associated to fermentation of carbohydrates by different bacterial strains. These results provide evidence for the potential use of prebiotics for beneficially modifying the gut microbial balance as well as host energy and lipid homeostasis. PMID:18628745

  9. Interaction of Human Apolipoprotein A-I with Model Membranes Exhibiting Lipid Domains

    PubMed Central

    Arnulphi, Cristina; Sánchez, Susana A.; Tricerri, M. Alejandra; Gratton, Enrico; Jonas, Ana

    2005-01-01

    Several mechanisms for cell cholesterol efflux have been proposed, including membrane microsolubilization, suggesting that the existence of specific domains could enhance the transfer of lipids to apolipoproteins. In this work isothermal titration calorimetry, circular dichroism spectroscopy, and two-photon microscopy are used to study the interaction of lipid-free apolipoprotein A-I (apoA-I) with small unilamellar vesicles (SUVs) of 1-palmitoyl, 2-oleoyl phosphatidylcholine (POPC) and sphingomyelin (SM), with and without cholesterol. Below 30°C the calorimetric results show that apoA-I interaction with POPC/SM SUVs produces an exothermic reaction, characterized as nonclassical hydrophobic binding. The heat capacity change (ΔCp°) is small and positive, whereas it was larger and negative for pure POPC bilayers, in the absence of SM. Inclusion of cholesterol in the membranes induces changes in the observed thermodynamic pattern of binding and counteracts the formation of α-helices in the protein. Above 30°C the reactions are endothermic. Giant unilamellar vesicles (GUVs) of identical composition to the SUVs, and two-photon fluorescence microscopy techniques, were utilized to further characterize the interaction. Fluorescence imaging of the GUVs indicates coexistence of lipid domains under 30°C. Binding experiments and Laurdan generalized-polarization measurements suggest that there is no preferential binding of the labeled apoA-I to any particular domain. Changes in the content of α-helix, binding, and fluidity data are discussed in the framework of the thermodynamic parameters. PMID:15849246

  10. A Computational Model of Active Vision for Visual Search in Human-Computer Interaction

    DTIC Science & Technology

    2010-08-01

    the Model Mixed Density Task CVC Task 3. ANSWERING THE FOUR QUESTIONS OF ACTIVE VISION 3.1. When do the Eyes Move? Modeling Fixation...from two experiments: a mixed density search task and a CVC (consonant-vowel- consonant) search task. The mixed density experiment (Halverson & Hornof...2004b) investigated the effects of varying the visual density of elements in a structured layout. The CVC search experiment (Hornof, 2004

  11. New Perspectives on Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Moran, Thomas P., Ed.; And Others

    1985-01-01

    Individual papers discussing various facets of human relationships with interactive computer systems present an analysis of direct manipulation interfaces; discuss notion of conceptual models shared by system and user and propose a design methodology for delivering models to users; and address the intelligibility of systems and importance of…

  12. Plume-Surface Interaction Modeling for a Human-Scale Mars Lander

    NASA Technical Reports Server (NTRS)

    Hart, Kenneth

    2017-01-01

    Landing vehicles impart thermal and strain energy onto the landing site from the retrorocket exhaust. Depending on the design of the vehicle, the energy may be great enough to cause spallation at the landing site. This damage may be minor and repairable in the case of landing on a terrestrial landing pad. For missions to other planetary bodies, the spallation may cause the landing site to become uneven and unstable, as well as damage. Simulating this phenomenon in a laboratory or computationally would require a significant amount of time and other resources. These resources typically are not available during the design phase of a mission. This paper presents a computationally-efficient model for the temperature and stress distributions that arise during landing. These quantities can be used along with existing failure criteria, such as the Hoek-Brown criterion for geological materials, to quickly determine whether spallation will occur. The stress and temperature distributions at the landing site are inherently 3D; however, there is a plane of symmetry and in that plane the distributions are 2D. Both quantities are modeled using series solutions to their governing partial differential equations (PDEs). The stress is modeled using the Airy stress potential function and its governing PDE is the biharmonic equation. The temperature is governed by Fourier's law. The models assume that stress due to gravity can be neglected, the points in the plane do not accelerate, and that the material properties are constant.

  13. Simulating human behavior for national security human interactions.

    SciTech Connect

    Bernard, Michael Lewis; Hart, Dereck H.; Verzi, Stephen J.; Glickman, Matthew R.; Wolfenbarger, Paul R.; Xavier, Patrick Gordon

    2007-01-01

    This 3-year research and development effort focused on what we believe is a significant technical gap in existing modeling and simulation capabilities: the representation of plausible human cognition and behaviors within a dynamic, simulated environment. Specifically, the intent of the ''Simulating Human Behavior for National Security Human Interactions'' project was to demonstrate initial simulated human modeling capability that realistically represents intra- and inter-group interaction behaviors between simulated humans and human-controlled avatars as they respond to their environment. Significant process was made towards simulating human behaviors through the development of a framework that produces realistic characteristics and movement. The simulated humans were created from models designed to be psychologically plausible by being based on robust psychological research and theory. Progress was also made towards enhancing Sandia National Laboratories existing cognitive models to support culturally plausible behaviors that are important in representing group interactions. These models were implemented in the modular, interoperable, and commercially supported Umbra{reg_sign} simulation framework.

  14. Multi-spectroscopic and molecular modelling approach to investigate the interaction of riboflavin with human serum albumin.

    PubMed

    Alam, Md Maroof; Abul Qais, Faizan; Ahmad, Iqbal; Alam, Parvez; Hasan Khan, Rizwan; Naseem, Imrana

    2017-03-09

    Riboflavin (RF) plays an important role in various metabolic redox reactions in the form of flavin adenine dinucleotide and flavin mononucleotide. Human serum albumin (HSA) is an important protein involved in the transportation of drugs, hormones, fatty acid and other molecules which determine the biodistribution and physiological fate of these molecules. In this study, we have investigated the interaction of riboflavin RF with HSA under simulative physiological conditions using various biophysical, calorimetric and molecular docking techniques. Results demonstrate the formation of riboflavin-HSA complex with binding constant in the order of 10(4) M(-1). Fluorescence spectroscopy confirms intermediate strength having a static mode of quenching with stoichiometry of 1:1. Experimental results suggest that the binding site of riboflavin mainly resides in sub-domain IIA of HSA and that ligand interaction increases the α-helical content of HSA. These parameters were further verified by isothermal titration calorimetry ITC which confirms the thermodynamic parameters obtained by fluorescence spectroscopy. Molecular docking was employed to suggest a binding model. Based on thermodynamic, spectroscopic and computational observations it can be concluded that HSA-riboflavin complex is mainly stabilized by various non-covalent forces with binding energy of -7.2 kcal mol(-1).

  15. A neuroanatomically grounded Hebbian-learning model of attention–language interactions in the human brain

    PubMed Central

    Garagnani, Max; Wennekers, Thomas; Pulvermüller, Friedemann

    2008-01-01

    Meaningful familiar stimuli and senseless unknown materials lead to different patterns of brain activation. A late major neurophysiological response indexing ‘sense’ is the negative component of event-related potential peaking at around 400 ms (N400), an event-related potential that emerges in attention-demanding tasks and is larger for senseless materials (e.g. meaningless pseudowords) than for matched meaningful stimuli (words). However, the mismatch negativity (latency 100–250 ms), an early automatic brain response elicited under distraction, is larger to words than to pseudowords, thus exhibiting the opposite pattern to that seen for the N400. So far, no theoretical account has been able to reconcile and explain these findings by means of a single, mechanistic neural model. We implemented a neuroanatomically grounded neural network model of the left perisylvian language cortex and simulated: (i) brain processes of early language acquisition and (ii) cortical responses to familiar word and senseless pseudoword stimuli. We found that variation of the area-specific inhibition (the model correlate of attention) modulated the simulated brain response to words and pseudowords, producing either an N400- or a mismatch negativity-like response depending on the amount of inhibition (i.e. available attentional resources). Our model: (i) provides a unifying explanatory account, at cortical level, of experimental observations that, so far, had not been given a coherent interpretation within a single framework; (ii) demonstrates the viability of purely Hebbian, associative learning in a multilayered neural network architecture; and (iii) makes clear predictions on the effects of attention on latency and magnitude of event-related potentials to lexical items. Such predictions have been confirmed by recent experimental evidence. PMID:18215243

  16. A neuroanatomically grounded Hebbian-learning model of attention-language interactions in the human brain.

    PubMed

    Garagnani, Max; Wennekers, Thomas; Pulvermüller, Friedemann

    2008-01-01

    Meaningful familiar stimuli and senseless unknown materials lead to different patterns of brain activation. A late major neurophysiological response indexing 'sense' is the negative component of event-related potential peaking at around 400 ms (N400), an event-related potential that emerges in attention-demanding tasks and is larger for senseless materials (e.g. meaningless pseudowords) than for matched meaningful stimuli (words). However, the mismatch negativity (latency 100-250 ms), an early automatic brain response elicited under distraction, is larger to words than to pseudowords, thus exhibiting the opposite pattern to that seen for the N400. So far, no theoretical account has been able to reconcile and explain these findings by means of a single, mechanistic neural model. We implemented a neuroanatomically grounded neural network model of the left perisylvian language cortex and simulated: (i) brain processes of early language acquisition and (ii) cortical responses to familiar word and senseless pseudoword stimuli. We found that variation of the area-specific inhibition (the model correlate of attention) modulated the simulated brain response to words and pseudowords, producing either an N400- or a mismatch negativity-like response depending on the amount of inhibition (i.e. available attentional resources). Our model: (i) provides a unifying explanatory account, at cortical level, of experimental observations that, so far, had not been given a coherent interpretation within a single framework; (ii) demonstrates the viability of purely Hebbian, associative learning in a multilayered neural network architecture; and (iii) makes clear predictions on the effects of attention on latency and magnitude of event-related potentials to lexical items. Such predictions have been confirmed by recent experimental evidence.

  17. A Cognitive Model of Human-Computer Interaction in Naval Air ASW Mission Management

    DTIC Science & Technology

    1989-12-15

    interface through which the a task would be performed. Using the performance-time predictions, alternative interface designs can be evaluated. Kieras has...extended the use of GOMS models for user interface design (Bovair, Kieras , & Poison, 1988; Kieras , 1988), deriving both quantitative and qualitative...Elkerton & Palmiter, 1989). Much of the work done to date with GOMS by Card, Newell, John, Kieras , and others has focused on the lowest level goals and

  18. Development of anatomically realistic numerical breast phantoms with accurate dielectric properties for modeling microwave interactions with the human breast.

    PubMed

    Zastrow, Earl; Davis, Shakti K; Lazebnik, Mariya; Kelcz, Frederick; Van Veen, Barry D; Hagness, Susan C

    2008-12-01

    Computational electromagnetics models of microwave interactions with the human breast serve as an invaluable tool for exploring the feasibility of new technologies and improving design concepts related to microwave breast cancer detection and treatment. In this paper, we report the development of a collection of anatomically realistic 3-D numerical breast phantoms of varying shape, size, and radiographic density which can readily be used in finite-difference time-domain computational electromagnetics models. The phantoms are derived from T1-weighted MRIs of prone patients. Each MRI is transformed into a uniform grid of dielectric properties using several steps. First, the structure of each phantom is identified by applying image processing techniques to the MRI. Next, the voxel intensities of the MRI are converted to frequency-dependent and tissue-dependent dielectric properties of normal breast tissues via a piecewise-linear map. The dielectric properties of normal breast tissue are taken from the recently completed large-scale experimental study of normal breast tissue dielectric properties conducted by the Universities of Wisconsin and Calgary. The comprehensive collection of numerical phantoms is made available to the scientific community through an online repository.

  19. Development of Anatomically Realistic Numerical Breast Phantoms with Accurate Dielectric Properties for Modeling Microwave Interactions with the Human Breast

    PubMed Central

    Zastrow, Earl; Davis, Shakti K.; Lazebnik, Mariya; Kelcz, Frederick; Van Veen, Barry D.; Hagness, Susan C.

    2008-01-01

    Computational electromagnetics models of microwave interactions with the human breast serve as an invaluable tool for exploring the feasibility of new technologies and improving design concepts related to microwave breast cancer detection and treatment. In this paper we report the development of a collection of anatomically realistic 3D numerical breast phantoms of varying shape, size, and radiographic density which can be readily used in FDTD computational electromagnetics models. The phantoms are derived from T1-weighted magnetic resonance images (MRIs) of prone patients. Each MRI is transformed into a uniform grid of dielectric properties using several steps. First, the structure of each phantom is identified by applying image processing techniques to the MRI. Next, the voxel intensities of the MRI are converted to frequency-dependent and tissue-dependent dielectric properties of normal breast tissues via a piecewise-linear map. The dielectric properties of normal breast tissue are taken from the recently completed large-scale experimental study of normal breast tissue dielectric properties conducted by the Universities of Wisconsin and Calgary. The comprehensive collection of numerical phantoms is made available to the scientific community through an online repository. PMID:19126460

  20. Modifications to an interactive model of the human body during exercise: With special emphasis on thermoregulation. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Scherb, Megan Kay

    1993-01-01

    Since 1988 an interactive computer model of the human body during exercise has been under development by a number of undergraduate students in the Department of Chemical Engineering at Iowa State University. The program, written under the direction of Dr. Richard C. Seagrave, uses physical characteristics of the user, environmental conditions and activity information to predict the onset of hypothermia, hyperthermia, dehydration, or exhaustion for various levels and durations of a specified exercise. The program however, was severely limited in predicting the onset of dehydration due to the lack of sophistication with which the program predicts sweat rate and its relationship to sensible water loss, degree of acclimatization, and level of physical training. Additionally, it was not known whether sweat rate also depended on age and gender. For these reasons, the goal of this creative component was to modify the program in the above mentioned areas by applying known information and empirical relationships from literature. Furthermore, a secondary goal was to improve the consistency with which the program was written by modifying user input statements and improving the efficiency and logic of the program calculations.

  1. Interaction of coomassie brilliant blue G250 with human serum albumin: Probing of the binding mechanism and binding site by spectroscopic and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Li, Yue-Sheng; Ge, Yu-Shu; Zhang, Yue; Zhang, Ai-Qing; Sun, Shao-Fa; Jiang, Feng-Lei; Liu, Yi

    2010-04-01

    The interaction between coomassie brilliant blue G250 and human serum albumin was investigated by spectroscopic methods such as fluorescence quenching, synchronous fluorescence , 3D fluorescence spectra, circular dichroism spectra and UV-vis absorption as well as molecular modeling. The fluorescence quenching of human serum albumin by coomassie brilliant blue G250 was attributed to static interaction. The binding reaction was mainly enthalpy-driven. Both van der Waals and hydrogen bonding forces played major roles in stabilizing the coomassie brilliant blue G250-human serum albumin complex. The Stern-Volmer quenching constant ( KSV) and corresponding thermodynamic parameters (Δ HΘ, Δ GΘ and Δ SΘ) were determined. Site marker competitive experiments indicated that coomassie brilliant blue G250 bound to site I (subdomain IIA) of human serum albumin. Molecular docking study further confirmed the binding mode obtained by experimental study. The conformational investigation demonstrated very minor micro-environmental and conformational changes in human serum albumin molecules.

  2. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas

    EPA Science Inventory

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment interactions. ...

  3. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas

    EPA Science Inventory

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment interactions. ...

  4. Experimental identification of the lateral human-structure interaction mechanism and assessment of the inverted-pendulum biomechanical model

    NASA Astrophysics Data System (ADS)

    Carroll, S. P.; Owen, J. S.; Hussein, M. F. M.

    2014-10-01

    Within the context of crowd-induced lateral bridge vibration, human-structure interaction (HSI) is a widely studied phenomenon. Central to this study is the self-excited component of the ground reaction force (GRF). This force harmonic, induced by a walking pedestrian, resonates with lateral deck motion, irrespective of the pedestrian's pacing frequency. Its presence can lead to positive feedback between pedestrian GRFs and structural motion. Characterisation of the self-excited force as equivalent structural mass and damping has greatly improved the understanding of HSI and its role in developing lateral dynamic instability. However, despite this evolving understanding, a key question has remained unanswered; what are the features of a pedestrian's balance response to base motion that gives rise to the self-excited force? The majority of the literature has focussed on the effects of HSI with the underlying mechanism receiving comparatively little attention. This paper presents data from experimental testing in which 10 subjects walked individually on a laterally oscillating treadmill. Lateral deck motion as well as the GRFs imposed by the subject was recorded. Three-dimensional motion capture equipment was used to track the position of visual markers mounted on the subject. Thus whole body response to base motion was captured in addition to the GRFs generated. The data presented herein supports the authors' previous findings that the self-excited force is a frequency sideband harmonic resulting from amplitude modulation of the lateral GRF. The gait behaviour responsible for this amplitude modulation is a periodic modulation of stride width in response to a sinusoidally varying inertia force induced by deck motion. In a separate analysis the validity of the passive inverted pendulum model, stabilised by active control of support placement was confirmed. This was established through comparison of simulated and observed frontal plane CoM motion. Despite the relative

  5. Human Factors Model

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Jack is an advanced human factors software package that provides a three dimensional model for predicting how a human will interact with a given system or environment. It can be used for a broad range of computer-aided design applications. Jack was developed by the computer Graphics Research Laboratory of the University of Pennsylvania with assistance from NASA's Johnson Space Center, Ames Research Center and the Army. It is the University's first commercial product. Jack is still used for academic purposes at the University of Pennsylvania. Commercial rights were given to Transom Technologies, Inc.

  6. Five Papers on Human-Machine Interaction.

    DTIC Science & Technology

    1982-05-01

    AD-AI6 031 CALIFORNIA UNIV SAN DIEGO LA JOLLA CENTER FOR HUMAN -- ETC FIG 5/ B FIVE PAPERS ON HUMAN-MACHINE INTERACTION.(U) MAY 82 0 A NORMAN N0001...model in order - -et the_ necessary results. Mental models will be constrained by such things as the user’s technical background, previous experiences ...especially apt to be the case when a person has experience with a number of different systems, all very similar, but each with some slightly different set of

  7. Multi-View Interaction Modelling of human collaboration processes: a business process study of head and neck cancer care in a Dutch academic hospital.

    PubMed

    Stuit, Marco; Wortmann, Hans; Szirbik, Nick; Roodenburg, Jan

    2011-12-01

    In the healthcare domain, human collaboration processes (HCPs), which consist of interactions between healthcare workers from different (para)medical disciplines and departments, are of growing importance as healthcare delivery becomes increasingly integrated. Existing workflow-based process modelling tools for healthcare process management, which are the most commonly applied, are not suited for healthcare HCPs mainly due to their focus on the definition of task sequences instead of the graphical description of human interactions. This paper uses a case study of a healthcare HCP at a Dutch academic hospital to evaluate a novel interaction-centric process modelling method. The HCP under study is the care pathway performed by the head and neck oncology team. The evaluation results show that the method brings innovative, effective, and useful features. First, it collects and formalizes the tacit domain knowledge of the interviewed healthcare workers in individual interaction diagrams. Second, the method automatically integrates these local diagrams into a single global interaction diagram that reflects the consolidated domain knowledge. Third, the case study illustrates how the method utilizes a graphical modelling language for effective tree-based description of interactions, their composition and routing relations, and their roles. A process analysis of the global interaction diagram is shown to identify HCP improvement opportunities. The proposed interaction-centric method has wider applicability since interactions are the core of most multidisciplinary patient-care processes. A discussion argues that, although (multidisciplinary) collaboration is in many cases not optimal in the healthcare domain, it is increasingly considered a necessity to improve integration, continuity, and quality of care. The proposed method is helpful to describe, analyze, and improve the functioning of healthcare collaboration.

  8. Study on the interaction of antiviral drug 'Tenofovir' with human serum albumin by spectral and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Hadidi, Saba; Feizi, Foroozan

    2015-03-01

    This study was designed to examine the interaction of Tenofovir (Ten) with human serum albumin (HSA) under physiological conditions. The binding of drugs with human serum albumin is a crucial factor influencing the distribution and bioactivity of drugs in the body. To understand the action mechanisms between Ten and HSA, the binding of Ten with HSA was investigated by a combined experimental and computational approach. UV-vis results confirmed that Ten interacted with HSA to form a ground-state complex and values of the Stern-Volmer quenching constant indicate the presence of a static component in the quenching mechanism. As indicated by the thermodynamic parameters (positive ΔH and ΔS values), hydrophobic interaction plays a major role in the Ten-HSA complex. Through the site marker competitive experiment, Ten was confirmed to be located in site I of HSA. Furthermore, UV-vis absorption spectra, synchronous fluorescence spectrum and CD data were used to investigate the structural change of HSA molecules with addition of Ten, the results indicate that the secondary structure of HSA molecules was changed in the presence of Ten. The experimental results were in agreement with the results obtained via molecular docking study.

  9. Study on the interaction of antiviral drug 'Tenofovir' with human serum albumin by spectral and molecular modeling methods.

    PubMed

    Shahabadi, Nahid; Hadidi, Saba; Feizi, Foroozan

    2015-03-05

    This study was designed to examine the interaction of Tenofovir (Ten) with human serum albumin (HSA) under physiological conditions. The binding of drugs with human serum albumin is a crucial factor influencing the distribution and bioactivity of drugs in the body. To understand the action mechanisms between Ten and HSA, the binding of Ten with HSA was investigated by a combined experimental and computational approach. UV-vis results confirmed that Ten interacted with HSA to form a ground-state complex and values of the Stern-Volmer quenching constant indicate the presence of a static component in the quenching mechanism. As indicated by the thermodynamic parameters (positive ΔH and ΔS values), hydrophobic interaction plays a major role in the Ten-HSA complex. Through the site marker competitive experiment, Ten was confirmed to be located in site I of HSA. Furthermore, UV-vis absorption spectra, synchronous fluorescence spectrum and CD data were used to investigate the structural change of HSA molecules with addition of Ten, the results indicate that the secondary structure of HSA molecules was changed in the presence of Ten. The experimental results were in agreement with the results obtained via molecular docking study. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Modeling the frictional interaction in the tendon-pulley system of the human finger for use in robotics.

    PubMed

    Dermitzakis, Konstantinos; Morales, Marco Roberto; Schweizer, Andreas

    2013-01-01

    Physiological studies of the human finger indicate that friction in the tendon-pulley system accounts for a considerable fraction of the total output force (9-12%) in a high-load static posteccentric configuration. Such a phenomenon can be exploited for robotic and prosthetic applications, as it can result in (1) an increase of output force or (2) a reduction of energy consumption and actuator weight. In this study, a simple frictional, two-link, one-degree-of-freedom model of a human finger was created. The model is validated against in vitro human finger data, and its behavior is examined with respect to select physiological parameters. The results point to clear benefits of incorporating friction in tendon-driven robotic fingers for actuator mass and output force. If it is indeed the case that the majority of high-load hand grasps are posteccentric, there is a clear benefit of incorporating friction in tendon-driven prosthetic hand replacements.

  11. Host-pathogen interactions between the human innate immune system and Candida albicans—understanding and modeling defense and evasion strategies

    PubMed Central

    Dühring, Sybille; Germerodt, Sebastian; Skerka, Christine; Zipfel, Peter F.; Dandekar, Thomas; Schuster, Stefan

    2015-01-01

    The diploid, polymorphic yeast Candida albicans is one of the most important human pathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within the human host for a long time. However, alterations in the host environment can render C. albicans virulent. In this review, we describe the immunological cross-talk between C. albicans and the human innate immune system. We give an overview in form of pairs of human defense strategies including immunological mechanisms as well as general stressors such as nutrient limitation, pH, fever etc. and the corresponding fungal response and evasion mechanisms. Furthermore, Computational Systems Biology approaches to model and investigate these complex interactions are highlighted with a special focus on game-theoretical methods and agent-based models. An outlook on interesting questions to be tackled by Systems Biology regarding entangled defense and evasion mechanisms is given. PMID:26175718

  12. Experiment-model interaction for analysis of epicardial activation during human ventricular fibrillation with global myocardial ischaemia.

    PubMed

    Clayton, R H; Nash, M P; Bradley, C P; Panfilov, A V; Paterson, D J; Taggart, P

    2011-10-01

    We describe a combined experiment-modelling framework to investigate the effects of ischaemia on the organisation of ventricular fibrillation in the human heart. In a series of experimental studies epicardial activity was recorded from 10 patients undergoing routine cardiac surgery. Ventricular fibrillation was induced by burst pacing, and recording continued during 2.5 min of global cardiac ischaemia followed by 30 s of coronary reflow. Modelling used a 2D description of human ventricular tissue. Global cardiac ischaemia was simulated by (i) decreased intracellular ATP concentration and subsequent activation of an ATP sensitive K⁺ current, (ii) elevated extracellular K⁺ concentration, and (iii) acidosis resulting in reduced magnitude of the L-type Ca²⁺ current I(Ca,L). Simulated ischaemia acted to shorten action potential duration, reduce conduction velocity, increase effective refractory period, and flatten restitution. In the model, these effects resulted in slower re-entrant activity that was qualitatively consistent with our observations in the human heart. However, the flattening of restitution also resulted in the collapse of many re-entrant waves to several stable re-entrant waves, which was different to the overall trend we observed in the experimental data. These findings highlight a potential role for other factors, such as structural or functional heterogeneity in sustaining wavebreak during human ventricular fibrillation with global myocardial ischaemia.

  13. 2D Computational Fluid Dynamic Modeling of Human Ventricle System Based on Fluid-Solid Interaction and Pulsatile Flow

    PubMed Central

    Masoumi, Nafiseh; Framanzad, F.; Zamanian, Behnam; Seddighi, A.S.; Moosavi, M.H.; Najarian, S.; Bastani, Dariush

    2013-01-01

    Many diseases are related to cerebrospinal fluid (CSF) hydrodynamics. Therefore, understanding the hydrodynamics of CSF flow and intracranial pressure is helpful for obtaining deeper knowledge of pathological processes and providing better treatments. Furthermore, engineering a reliable computational method is promising approach for fabricating in vitro models which is essential for inventing generic medicines. A Fluid-Solid Interaction (FSI)model was constructed to simulate CSF flow. An important problem in modeling the CSF flow is the diastolic back flow. In this article, using both rigid and flexible conditions for ventricular system allowed us to evaluate the effect of surrounding brain tissue. Our model assumed an elastic wall for the ventricles and a pulsatile CSF input as its boundary conditions. A comparison of the results and the experimental data was done. The flexible model gave better results because it could reproduce the diastolic back flow mentioned in clinical research studies. The previous rigid models have ignored the brain parenchyma interaction with CSF and so had not reported the back flow during the diastolic time. In this computational fluid dynamic (CFD) analysis, the CSF pressure and flow velocity in different areas were concordant with the experimental data. PMID:25337330

  14. 2D Computational Fluid Dynamic Modeling of Human Ventricle System Based on Fluid-Solid Interaction and Pulsatile Flow.

    PubMed

    Masoumi, Nafiseh; Framanzad, F; Zamanian, Behnam; Seddighi, A S; Moosavi, M H; Najarian, S; Bastani, Dariush

    2013-01-01

    Many diseases are related to cerebrospinal fluid (CSF) hydrodynamics. Therefore, understanding the hydrodynamics of CSF flow and intracranial pressure is helpful for obtaining deeper knowledge of pathological processes and providing better treatments. Furthermore, engineering a reliable computational method is promising approach for fabricating in vitro models which is essential for inventing generic medicines. A Fluid-Solid Interaction (FSI)model was constructed to simulate CSF flow. An important problem in modeling the CSF flow is the diastolic back flow. In this article, using both rigid and flexible conditions for ventricular system allowed us to evaluate the effect of surrounding brain tissue. Our model assumed an elastic wall for the ventricles and a pulsatile CSF input as its boundary conditions. A comparison of the results and the experimental data was done. The flexible model gave better results because it could reproduce the diastolic back flow mentioned in clinical research studies. The previous rigid models have ignored the brain parenchyma interaction with CSF and so had not reported the back flow during the diastolic time. In this computational fluid dynamic (CFD) analysis, the CSF pressure and flow velocity in different areas were concordant with the experimental data.

  15. JSPAM: Interacting galaxies modeller

    NASA Astrophysics Data System (ADS)

    Wallin, John F.; Holincheck, Anthony; Harvey, Allen

    2015-11-01

    JSPAM models galaxy collisions using a restricted n-body approach to speed up computation. Instead of using a softened point-mass potential, the software supports a modified version of the three component potential created by Hernquist (1994, ApJS 86, 389). Although spherically symmetric gravitationally potentials and a Gaussian model for the bulge are used to increase computational efficiency, the potential mimics that of a fully consistent n-body model of a galaxy. Dynamical friction has been implemented in the code to improve the accuracy of close approaches between galaxies. Simulations using this code using thousands of particles over the typical interaction times of a galaxy interaction take a few seconds on modern desktop workstations, making it ideal for rapidly prototyping the dynamics of colliding galaxies. Extensive testing of the code has shown that it produces nearly identical tidal features to those from hierarchical tree codes such as Gadget but using a fraction of the computational resources. This code was used in the Galaxy Zoo: Mergers project and is very well suited for automated fitting of galaxy mergers with automated pattern fitting approaches such as genetic algorithms. Java and Fortran versions of the code are available.

  16. Interactive Water Resources Modeling and Model Use: An Overview

    NASA Astrophysics Data System (ADS)

    Loucks, Daniel P.; Kindler, Janusz; Fedra, Kurt

    1985-02-01

    This serves as an introduction for the following sequence of five papers on interactive water resources and environmental management, policy modeling, and model use. We review some important shortcomings of many management and policy models and argue for improved human-computer-model interaction and communication. This interaction can lead to more effective model use which in turn should facilitate the exploration, analysis, and synthesis of alternative designs, plans, and policies by those directly involved in the planning, management, or policy making process. Potential advantages of interactive modeling and model use, as well as some problems and research needs, are discussed.

  17. Interactive production planning and ergonomic assessment with Digital Human Models--introducing the Editor for Manual Work Activities (ema).

    PubMed

    Fritzsche, Lars; Leidholdt, Wolfgang; Bauer, Sebastian; Jäckel, Thomas; Moreno, Adrian

    2012-01-01

    The aging workforce is a risk factor for manufacturing industries that contain many jobs with high physical workloads. Thus, ergonomic risk factors have to be avoided in early phases of production planning. This paper introduces a new tool for simulating manual work activities with 3D human models, the so-called emaΦ. For the most part, the emaΦ software is based on a unique modular approach including a number of complex operations that were theoretically developed and empirically validated by means of motion capturing technologies. Using these modules for defining the digital work process enables the production planner to compile human simulations more accurately and much quicker compared to any of the existing modeling tools. Features of the emaΦ software implementation, such as ergonomic evaluation and MTM-time analyses, and the workflow for practical application are presented.

  18. Development of a bioengineered skin-humanized mouse model for psoriasis: dissecting epidermal-lymphocyte interacting pathways.

    PubMed

    Guerrero-Aspizua, Sara; García, Marta; Murillas, Rodolfo; Retamosa, Luisa; Illera, Nuria; Duarte, Blanca; Holguín, Almudena; Puig, Susana; Hernández, Maria Isabel; Meana, Alvaro; Jorcano, Jose Luis; Larcher, Fernando; Carretero, Marta; Del Río, Marcela

    2010-12-01

    Over the past few years, whole skin xenotransplantation models that mimic different aspects of psoriasis have become available. However, these models are strongly constrained by the lack of skin donor availability and homogeneity. We present in this study a bioengineering-based skin-humanized mouse model for psoriasis, either in an autologous version using samples derived from psoriatic patients or, more importantly, in an allogeneic context, starting from skin biopsies and blood samples from unrelated healthy donors. After engraftment, the regenerated human skin presents the typical architecture of normal human skin but, in both cases, immunological reconstitution through intradermal injection in the regenerated skin using in vitro-differentiated T1 subpopulations as well as recombinant IL-17 and IL-22 Th17 cytokines, together with removal of the stratum corneum barrier by a mild abrasive treatment, leads to the rapid conversion of the skin into a bona fide psoriatic phenotype. Major hallmarks of psoriasis were confirmed by the evaluation of specific epidermal differentiation and proliferation markers as well as the mesenchymal milieu, including angiogenesis and infiltrate. Our bioengineered skin-based system represents a robust platform to reliably assess the molecular and cellular mechanisms underlying the complex interdependence between epidermal cells and the immune system. The system may also prove suitable to assess preclinical studies that test the efficacy of novel therapeutic treatments and to predict individual patient response to therapy.

  19. Human thrombospondin's (TSP-1) C-terminal domain opens to interact with the CD-47 receptor: a molecular modeling study.

    PubMed

    Floquet, Nicolas; Dedieu, Stéphane; Martiny, Laurent; Dauchez, Manuel; Perahia, David

    2008-10-01

    Thrombospondin-1 (TSP-1) interaction with the membranous receptor CD-47 involves the peptide RFYVVMWK (4N-1) located in its C-terminal domain. However, the available X-ray structure of TSP-1 describes this peptide as completely buried into a hydrophobic pocket, preventing any interaction. Where classical standard methods failed, an appropriate approach combining normal mode analysis and an adapted protocol of energy minimization identified the large amplitude motions responsible of the partial solvent exposure of 4N-1. In agreement, the obtained model of the open TSP-1 was further used for protein-protein docking experiments against a homology model generated for CD-47. Considering the multiple applications of the CD-47 receptor as a target, our results open new pharmacological perspectives for the design of TSP-1:CD-47 inhibitors and CD-47 antagonists. We also suggest a common opening mechanism for proteins sharing the same fold as TSP-1. This work also suggests the usefulness of our approach in other topics in which predictions of protein-protein interactions are of importance.

  20. Interaction of Citrinin with Human Serum Albumin

    PubMed Central

    Poór, Miklós; Lemli, Beáta; Bálint, Mónika; Hetényi, Csaba; Sali, Nikolett; Kőszegi, Tamás; Kunsági-Máté, Sándor

    2015-01-01

    Citrinin (CIT) is a mycotoxin produced by several Aspergillus, Penicillium, and Monascus species. CIT occurs worldwide in different foods and drinks and causes health problems for humans and animals. Human serum albumin (HSA) is the most abundant plasma protein in human circulation. Albumin forms stable complexes with many drugs and xenobiotics; therefore, HSA commonly plays important role in the pharmacokinetics or toxicokinetics of numerous compounds. However, the interaction of CIT with HSA is poorly characterized yet. In this study, the complex formation of CIT with HSA was investigated using fluorescence spectroscopy and ultrafiltration techniques. For the deeper understanding of the interaction, thermodynamic, and molecular modeling studies were performed as well. Our results suggest that CIT forms stable complex with HSA (logK ~ 5.3) and its primary binding site is located in subdomain IIA (Sudlow’s Site I). In vitro cell experiments also recommend that CIT-HSA interaction may have biological relevance. Finally, the complex formations of CIT with bovine, porcine, and rat serum albumin were investigated, in order to test the potential species differences of CIT-albumin interactions. PMID:26633504

  1. Ridge Regression for Interactive Models.

    ERIC Educational Resources Information Center

    Tate, Richard L.

    1988-01-01

    An exploratory study of the value of ridge regression for interactive models is reported. Assuming that the linear terms in a simple interactive model are centered to eliminate non-essential multicollinearity, a variety of common models, representing both ordinal and disordinal interactions, are shown to have "orientations" that are…

  2. Critical insight into the interaction of naringenin with human haemoglobin: A combined spectroscopic and computational modeling approaches

    NASA Astrophysics Data System (ADS)

    Maity, Subhajit; Chakraborty, Sandipan; Chakraborti, Abhay Sankar

    2017-02-01

    The present study demonstrates critical insight into the binding of a bioactive flavanone naringenin with normal human haemoglobin (NHb). Both spectrophotometric and spectrofluorimetric studies reveal that naringenin interacts with NHb. The binding affinity constant and number of binding sites appear to be approximately (1.5 ± 0.2) × 104 M-1 and 1, respectively. Static quenching seems to be an important factor in binding process, as evident from steady-state and time-resolved fluorescence spectroscopic studies. Far UV circular dichroism spectroscopy depicts that binding of naringenin to NHb causes no change in the secondary structure of the protein, which is also evident from Fourier transform infrared spectroscopic study. Free energy change (ΔG0) for naringenin-NHb interaction, determined by spectroscopic and isothermal calorimetric method, appears to be -5.67 kcal/mol and -6.90 kcal/mol, respectively, and is close to the docking energy -6.84 kcal/mol. Molecular docking suggests that naringenin binds near the cavity of the tetrameric heme protein, forming hydrogen bonds with surrounding amino acid residues. The binding site is away from the heme moieties, implicating naringenin binding does not affect the oxygen binding capacity of NHb, which makes the protein a suitable carrier of the flavonoid.

  3. Insight into the interaction of antitubercular and anticancer compound clofazimine with human serum albumin: spectroscopy and molecular modelling.

    PubMed

    Ajmal, Mohammad Rehan; Zaidi, Nida; Alam, Parvez; Nusrat, Saima; Siddiqi, Mohd Khursheed; Badr, Gamal; Mahmoud, Mohamed H; Khan, Rizwan Hasan

    2017-01-01

    The binding of clofazimine to human serum albumin (HSA) was investigated by applying optical spectroscopy and molecular docking methods. Fluorescence quenching data revealed that clofazimine binds to protein with binding constant in the order of 10(4) M(-1), and with the increase in temperature, Stern-Volmer quenching constants gradually decreased indicating quenching mode to be static. The UV-visible spectra showed increase in absorbance upon interaction of HSA with clofazimine which further reveals formation of the drug-albumin complex. Thermodynamic parameters obtained from fluorescence data indicate that the process is exothermic and spontaneous. Forster distance (Ro) obtained from fluorescence resonance energy transfer is found to be 2.05 nm. Clofazimine impelled rise in α-helical structure in HSA as observed from far-UV CD spectra while there are minor alterations in tertiary structure of the protein. Clofazimine interacts strongly with HSA inducing secondary structure in the protein and slight alterations in protein topology as suggested by dynamic light scattering results. Moreover, docking results indicate that clofazimine binds to hydrophobic pocket near to the drug site II in HSA.

  4. The 57Fe hyperfine interactions in human liver ferritin and its iron-polymaltose analogues: the heterogeneous iron core model

    NASA Astrophysics Data System (ADS)

    Oshtrakh, M. I.; Alenkina, I. V.; Semionkin, V. A.

    2016-12-01

    Human liver ferritin and its iron-polymaltose pharmaceutical analogues Ferrum Lek, Maltofer® and Ferrifol® were studied using Mössbauer spectroscopy at 295 and 90 K. The Mössbauer spectra were fitted on the basis of a new model of heterogeneous iron core structure using five quadrupole doublets. These components were related to the corresponding more or less close-packed iron core layers/regions demonstrating some variations in the 57Fe hyperfine parameters for the studied samples.

  5. Human-environment interactions and sustainable urban development: Spatial modeling and landscape prediction the case of Nang Rong town, Thailand

    NASA Astrophysics Data System (ADS)

    Varnakovida, Pariwate

    It is now well-recognized that, at local, regional, and global scales, land use changes are significantly altering land cover, perhaps at an accelerating pace. Further, the world's scientific community is increasingly recognizing what, in retrospect, should have been obvious, that human behavior and agency is a critical driver of Land Cover and Land Use Change. In this research, using recently developed computer modeling procedures and a rich case study, I develop spatially-explicit model-based simulations of LULCC scenarios within the rubric of sustainability science for Nang Rong town, Thailand. The research draws heavily on recent work in geography and complexity theory. A series of scenarios were built to explore different development trajectories based upon empirically observed relationships. The development models incorporate a) history and spatial pattern of village settlement; b) road development and changing geographic accessibility; c) population; d) biophysical characteristics and e) social drivers. This research uses multi-temporal and spatially-explicit data, analytic results, and dynamic modeling approaches combined with to describe, explain, and explore LULCC as the consequences of different production theories for rural, small town urbanization in the South East Asian context. Two Agent Based models were built: 1) Settlement model and 2) Land-use model. The Settlement model suggests that new development will emerge along the existing road network especially along the major highway and in close proximity to the urban center. If the population doubles in 2021, the settlement process may inhibit development along some corridors creating low density sprawl. The Land-use model under the urban expansion scenario suggests that new settlements will occur in close proximity to the town center and roads; even though, the area is suitable for rice farming or located on a flood plain. The Land-use model under the cash-crop expansion scenario captures that new

  6. Investigations on the interactions between naphthalimide-based anti-tumor drugs and human serum albumin by spectroscopic and molecular modeling methods.

    PubMed

    Cheng, Huiyuan; Zou, Ting; Xu, Yongliang; Wang, Ying; Wu, Aibin; Dai, Jie; Zhang, Yezhong; Liu, Yi

    2016-02-01

    The interactions between the three kinds of naphthalimide-based anti-tumor drugs (NADA, NADB, NADC) and human serum albumin (HSA) under simulated physiological conditions were investigated by fluorescence spectroscopy, circular dichroism spectroscopy and molecular modeling. The results of the fluorescence quenching spectroscopy showed that the quenching mechanisms for different drugs were static and their affinity was in a descending order of NADA > NADB > NADC. The relative thermodynamic parameters indicated that hydrophobic force was the predominant intermolecular force in the binding of NAD to HSA, while van der Waals interactions and hydrogen bonds could not be ignored. The results of site marker competitive experiment confirmed that the binding site of HSA primarily took place in site I. Furthermore, the molecular modeling study was consistent with these results. The study of circular dichroism spectra demonstrated that the presence of NADs decreased the α-helical content of HSA and induced the change of the secondary structure of HSA.

  7. In Silico Structure Prediction of Human Fatty Acid Synthase-Dehydratase: A Plausible Model for Understanding Active Site Interactions.

    PubMed

    John, Arun; Umashankar, Vetrivel; Samdani, A; Sangeetha, Manoharan; Krishnakumar, Subramanian; Deepa, Perinkulam Ravi

    2016-01-01

    Fatty acid synthase (FASN, UniProt ID: P49327) is a multienzyme dimer complex that plays a critical role in lipogenesis. Consequently, this lipogenic enzyme has gained tremendous biomedical importance. The role of FASN and its inhibition is being extensively researched in several clinical conditions, such as cancers, obesity, and diabetes. X-ray crystallographic structures of some of its domains, such as β-ketoacyl synthase, acetyl transacylase, malonyl transacylase, enoyl reductase, β-ketoacyl reductase, and thioesterase, (TE) are already reported. Here, we have attempted an in silico elucidation of the uncrystallized dehydratase (DH) catalytic domain of human FASN. This theoretical model for DH domain was predicted using comparative modeling methods. Different stand-alone tools and servers were used to validate and check the reliability of the predicted models, which suggested it to be a highly plausible model. The stereochemical analysis showed 92.0% residues in favorable region of Ramachandran plot. The initial physiological substrate β-hydroxybutyryl group was docked into active site of DH domain using Glide. The molecular dynamics simulations carried out for 20 ns in apo and holo states indicated the stability and accuracy of the predicted structure in solvated condition. The predicted model provided useful biochemical insights into the substrate-active site binding mechanisms. This model was then used for identifying potential FASN inhibitors using high-throughput virtual screening of the National Cancer Institute database of chemical ligands. The inhibitory efficacy of the top hit ligands was validated by performing molecular dynamics simulation for 20 ns, where in the ligand NSC71039 exhibited good enzyme inhibition characteristics and exhibited dose-dependent anticancer cytotoxicity in retinoblastoma cancer cells in vitro.

  8. In Silico Structure Prediction of Human Fatty Acid Synthase–Dehydratase: A Plausible Model for Understanding Active Site Interactions

    PubMed Central

    John, Arun; Umashankar, Vetrivel; Samdani, A.; Sangeetha, Manoharan; Krishnakumar, Subramanian; Deepa, Perinkulam Ravi

    2016-01-01

    Fatty acid synthase (FASN, UniProt ID: P49327) is a multienzyme dimer complex that plays a critical role in lipogenesis. Consequently, this lipogenic enzyme has gained tremendous biomedical importance. The role of FASN and its inhibition is being extensively researched in several clinical conditions, such as cancers, obesity, and diabetes. X-ray crystallographic structures of some of its domains, such as β-ketoacyl synthase, acetyl transacylase, malonyl transacylase, enoyl reductase, β-ketoacyl reductase, and thioesterase, (TE) are already reported. Here, we have attempted an in silico elucidation of the uncrystallized dehydratase (DH) catalytic domain of human FASN. This theoretical model for DH domain was predicted using comparative modeling methods. Different stand-alone tools and servers were used to validate and check the reliability of the predicted models, which suggested it to be a highly plausible model. The stereochemical analysis showed 92.0% residues in favorable region of Ramachandran plot. The initial physiological substrate β-hydroxybutyryl group was docked into active site of DH domain using Glide. The molecular dynamics simulations carried out for 20 ns in apo and holo states indicated the stability and accuracy of the predicted structure in solvated condition. The predicted model provided useful biochemical insights into the substrate–active site binding mechanisms. This model was then used for identifying potential FASN inhibitors using high-throughput virtual screening of the National Cancer Institute database of chemical ligands. The inhibitory efficacy of the top hit ligands was validated by performing molecular dynamics simulation for 20 ns, where in the ligand NSC71039 exhibited good enzyme inhibition characteristics and exhibited dose-dependent anticancer cytotoxicity in retinoblastoma cancer cells in vitro. PMID:27559295

  9. Acquisition and production of skilled behavior in dynamic decision-making tasks: Modeling strategic behavior in human-automation interaction: Why and aid can (and should) go unused

    NASA Technical Reports Server (NTRS)

    Kirlik, Alex

    1991-01-01

    Advances in computer and control technology offer the opportunity for task-offload aiding in human-machine systems. A task-offload aid (e.g., an autopilot, an intelligent assistant) can be selectively engaged by the human operator to dynamically delegate tasks to an automated system. Successful design and performance prediction in such systems requires knowledge of the factors influencing the strategy the operator develops and uses for managing interaction with the task-offload aid. A model is presented that shows how such strategies can be predicted as a function of three task context properties (frequency and duration of secondary tasks and costs of delaying secondary tasks) and three aid design properties (aid engagement and disengagement times, aid performance relative to human performance). Sensitivity analysis indicates how each of these contextual and design factors affect the optimal aid aid usage strategy and attainable system performance. The model is applied to understanding human-automation interaction in laboratory experiments on human supervisory control behavior. The laboratory task allowed subjects freedom to determine strategies for using an autopilot in a dynamic, multi-task environment. Modeling results suggested that many subjects may indeed have been acting appropriately by not using the autopilot in the way its designers intended. Although autopilot function was technically sound, this aid was not designed with due regard to the overall task context in which it was placed. These results demonstrate the need for additional research on how people may strategically manage their own resources, as well as those provided by automation, in an effort to keep workload and performance at acceptable levels.

  10. The Human-Robot Interaction Operating System

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Kunz, Clayton; Hiatt, Laura M.; Bugajska, Magda

    2006-01-01

    In order for humans and robots to work effectively together, they need to be able to converse about abilities, goals and achievements. Thus, we are developing an interaction infrastructure called the "Human-Robot Interaction Operating System" (HRI/OS). The HRI/OS provides a structured software framework for building human-robot teams, supports a variety of user interfaces, enables humans and robots to engage in task-oriented dialogue, and facilitates integration of robots through an extensible API.

  11. TFBSbank: a platform to dissect the big data of protein–DNA interaction in human and model species

    PubMed Central

    Chen, Dongsheng; Jiang, Sanjie; Ma, Xiaoyan; Li, Fang

    2017-01-01

    Genome-wide transcription factors (TFs) binding data has been extensively generated in the past few years, which poses a great challenge to data interpretation. Therefore, comprehensive and dedicated functional annotation databases for TF–DNA interaction are in great demands to manage, explore and utilize those invaluable data resources. Here, we constructed a platform ‘TFBSbank’ which houses the annotation of 1870 chromatin immunoprecipitation (ChIP) datasets of 585 TFs in five species (human, mouse, fly, worm and yeast). There are mainly five functional modules in TFBSbank aimed at characterizing ChIP peaks, identifying putative targets, predicting TF responsive enhancers, revealing potential cofactors/collaborators and discovering enriched TF motifs. TFBSbank has two distinctive features compared to the existing databases. Firstly, we provided putative cofactors/collaborators analysis (for Drosophila melanogaster), as they are crucial for the in vivo functions of TFs. Additionally, this database predicted the enrichment of both known and de novo motifs based on ChIP data. TFBSbank is freely accessible at http://tfbsbank.co.uk PMID:27899608

  12. Modeling Forces on the Human Body.

    ERIC Educational Resources Information Center

    Pagonis, Vasilis; Drake, Russel; Morgan, Michael; Peters, Todd; Riddle, Chris; Rollins, Karen

    1999-01-01

    Presents five models of the human body as a mechanical system which can be used in introductory physics courses: human arms as levers, humans falling from small heights, a model of the human back, collisions during football, and the rotating gymnast. Gives ideas for discussions and activities, including Interactive Physics (TM) simulations. (WRM)

  13. Modeling Forces on the Human Body.

    ERIC Educational Resources Information Center

    Pagonis, Vasilis; Drake, Russel; Morgan, Michael; Peters, Todd; Riddle, Chris; Rollins, Karen

    1999-01-01

    Presents five models of the human body as a mechanical system which can be used in introductory physics courses: human arms as levers, humans falling from small heights, a model of the human back, collisions during football, and the rotating gymnast. Gives ideas for discussions and activities, including Interactive Physics (TM) simulations. (WRM)

  14. Monitoring Dynamic Interactions between Breast Cancer Cells and Human Bone Tissue in a Co-Culture Model

    PubMed Central

    Contag, Christopher H.; Lie, Wen-Rong; Bammer, Marie C.; Hardy, Jonathan W.; Schmidt, Tobi L.; Maloney, William J.; King, Bonnie L.

    2015-01-01

    Purpose Bone is a preferential site of breast cancer metastasis and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue. Procedures Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell division and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX® immunoassays. Results BLI demonstrated increased MDA-MB-231-fLuc proliferation (p<0.001) in the presence vs. absence of bones, and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc colonization of bone, and MILLIPLEX® profiles of culture supernatants suggested breast/bone crosstalk. Conclusions Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays. PMID:24008275

  15. Monitoring dynamic interactions between breast cancer cells and human bone tissue in a co-culture model.

    PubMed

    Contag, Christopher H; Lie, Wen-Rong; Bammer, Marie C; Hardy, Jonathan W; Schmidt, Tobi L; Maloney, William J; King, Bonnie L

    2014-04-01

    Bone is a preferential site of breast cancer metastasis, and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue. Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell proliferation and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX(®) immunoassays. BLI demonstrated increased MDA-MB-231-fLuc cell proliferation (p < 0.001) in the presence vs. absence of bones and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc cell colonization of bone, and MILLIPLEX(®) profiles of culture supernatants suggested breast/bone crosstalk. Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays.

  16. Interaction of a peptide derived from C-terminus of human TRPA1 channel with model membranes mimicking the inner leaflet of the plasma membrane.

    PubMed

    Witschas, Katja; Jobin, Marie-Lise; Korkut, Dursun Nizam; Vladan, Maria Magdalena; Salgado, Gilmar; Lecomte, Sophie; Vlachova, Viktorie; Alves, Isabel D

    2015-05-01

    The transient receptor potential ankyrin 1 channel (TRPA1) belongs to the TRP cation channel superfamily that responds to a panoply of stimuli such as changes in temperature, calcium levels, reactive oxygen and nitrogen species and lipid mediators among others. The TRP superfamily has been implicated in diverse pathological states including neurodegenerative disorders, kidney diseases, inflammation, pain and cancer. The intracellular C-terminus is an important regulator of TRP channel activity. Studies with this and other TRP superfamily members have shown that the C-terminus association with lipid bilayer alters channel sensitivity and activation, especially interactions occurring through basic residues. Nevertheless, it is not yet clear how this process takes place and which regions in the C-terminus would be responsible for such membrane recognition. With that in mind, herein the first putative membrane interacting region of the C-terminus of human TRPA1, (corresponding to a 29 residue peptide, IAEVQKHASLKRIAMQVELHTSLEKKLPL) named H1 due to its potential helical character was chosen for studies of membrane interaction. The affinity of H1 to lipid membranes, H1 structural changes occurring upon this interaction as well as effects of this interaction in lipid organization and integrity were investigated using a biophysical approach. Lipid models systems composed of zwitterionic and anionic lipids, namely those present in the lipid membrane inner leaflet, where H1 is prone to interact, where used. The study reveals a strong interaction and affinity of H1 as well as peptide structuration especially with membranes containing anionic lipids. Moreover, the interactions and peptide structure adoption are headgroup specific. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Improved predictive ability of climate-human-behaviour interactions with modifications to the COMFA outdoor energy budget model.

    PubMed

    Vanos, J K; Warland, J S; Gillespie, T J; Kenny, N A

    2012-11-01

    The purpose of this paper is to implement current and novel research techniques in human energy budget estimations to give more accurate and efficient application of models by a variety of users. Using the COMFA model, the conditioning level of an individual is incorporated into overall energy budget predictions, giving more realistic estimations of the metabolism experienced at various fitness levels. Through the use of VO(2) reserve estimates, errors are found when an elite athlete is modelled as an unconditioned or a conditioned individual, giving budgets underpredicted significantly by -173 and -123 W m(-2), respectively. Such underprediction can result in critical errors regarding heat stress, particularly in highly motivated individuals; thus this revision is critical for athletic individuals. A further improvement in the COMFA model involves improved adaptation of clothing insulation (I (cl)), as well clothing non-uniformity, with changing air temperature (T (a)) and metabolic activity (M (act)). Equivalent T (a) values (for I (cl) estimation) are calculated in order to lower the I (cl) value with increasing M (act) at equal T (a). Furthermore, threshold T (a) values are calculated to predict the point at which an individual will change from a uniform I (cl) to a segmented I (cl) (full ensemble to shorts and a T-shirt). Lastly, improved relative velocity (v (r)) estimates were found with a refined equation accounting for the degree angle of wind to body movement. Differences between the original and improved v (r) equations increased with higher wind and activity speeds, and as the wind to body angle moved away from 90°. Under moderate microclimate conditions, and wind from behind a person, the convective heat loss and skin temperature estimates were 47 W m(-2) and 1.7°C higher when using the improved v (r) equation. These model revisions improve the applicability and usability of the COMFA energy budget model for subjects performing physical

  18. Improved predictive ability of climate-human-behaviour interactions with modifications to the COMFA outdoor energy budget model

    NASA Astrophysics Data System (ADS)

    Vanos, J. K.; Warland, J. S.; Gillespie, T. J.; Kenny, N. A.

    2012-11-01

    The purpose of this paper is to implement current and novel research techniques in human energy budget estimations to give more accurate and efficient application of models by a variety of users. Using the COMFA model, the conditioning level of an individual is incorporated into overall energy budget predictions, giving more realistic estimations of the metabolism experienced at various fitness levels. Through the use of VO2 reserve estimates, errors are found when an elite athlete is modelled as an unconditioned or a conditioned individual, giving budgets underpredicted significantly by -173 and -123 W m-2, respectively. Such underprediction can result in critical errors regarding heat stress, particularly in highly motivated individuals; thus this revision is critical for athletic individuals. A further improvement in the COMFA model involves improved adaptation of clothing insulation ( I cl), as well clothing non-uniformity, with changing air temperature ( T a) and metabolic activity ( M act). Equivalent T a values (for I cl estimation) are calculated in order to lower the I cl value with increasing M act at equal T a. Furthermore, threshold T a values are calculated to predict the point at which an individual will change from a uniform I cl to a segmented I cl (full ensemble to shorts and a T-shirt). Lastly, improved relative velocity ( v r) estimates were found with a refined equation accounting for the degree angle of wind to body movement. Differences between the original and improved v r equations increased with higher wind and activity speeds, and as the wind to body angle moved away from 90°. Under moderate microclimate conditions, and wind from behind a person, the convective heat loss and skin temperature estimates were 47 W m-2 and 1.7°C higher when using the improved v r equation. These model revisions improve the applicability and usability of the COMFA energy budget model for subjects performing physical activity in outdoor environments

  19. Application of physiologically based pharmacokinetic modeling in predicting drug–drug interactions for sarpogrelate hydrochloride in humans

    PubMed Central

    Min, Jee Sun; Kim, Doyun; Park, Jung Bae; Heo, Hyunjin; Bae, Soo Hyeon; Seo, Jae Hong; Oh, Euichaul; Bae, Soo Kyung

    2016-01-01

    Background Evaluating the potential risk of metabolic drug–drug interactions (DDIs) is clinically important. Objective To develop a physiologically based pharmacokinetic (PBPK) model for sarpogrelate hydrochloride and its active metabolite, (R,S)-1-{2-[2-(3-methoxyphenyl)ethyl]-phenoxy}-3-(dimethylamino)-2-propanol (M-1), in order to predict DDIs between sarpogrelate and the clinically relevant cytochrome P450 (CYP) 2D6 substrates, metoprolol, desipramine, dextromethorphan, imipramine, and tolterodine. Methods The PBPK model was developed, incorporating the physicochemical and pharmacokinetic properties of sarpogrelate hydrochloride, and M-1 based on the findings from in vitro and in vivo studies. Subsequently, the model was verified by comparing the predicted concentration-time profiles and pharmacokinetic parameters of sarpogrelate and M-1 to the observed clinical data. Finally, the verified model was used to simulate clinical DDIs between sarpogrelate hydrochloride and sensitive CYP2D6 substrates. The predictive performance of the model was assessed by comparing predicted results to observed data after coadministering sarpogrelate hydrochloride and metoprolol. Results The developed PBPK model accurately predicted sarpogrelate and M-1 plasma concentration profiles after single or multiple doses of sarpogrelate hydrochloride. The simulated ratios of area under the curve and maximum plasma concentration of metoprolol in the presence of sarpogrelate hydrochloride to baseline were in good agreement with the observed ratios. The predicted fold-increases in the area under the curve ratios of metoprolol, desipramine, imipramine, dextromethorphan, and tolterodine following single and multiple sarpogrelate hydrochloride oral doses were within the range of ≥1.25, but <2-fold, indicating that sarpogrelate hydrochloride is a weak inhibitor of CYP2D6 in vivo. Collectively, the predicted low DDIs suggest that sarpogrelate hydrochloride has limited potential for causing

  20. Assessing the interactions of a natural antibacterial clay with model Gram-positive and Gram-negative human pathogens

    NASA Astrophysics Data System (ADS)

    Londono, S. C.; Williams, L. B.

    2013-12-01

    The emergence of antibiotic resistant bacteria and increasing accumulations of antibiotics in reclaimed water, drive the quest for new natural antimicrobials. We are studying the antibacterial mechanism(s) of clays that have shown an ability to destroy bacteria or significantly inhibit their growth. One possible mode of action is from soluble transition metal species, particularly reduced Fe, capable of generating deleterious oxygen radical species. Yet another possibility is related to membrane damage as a consequence of physical or electrostatic interaction between clay and bacteria. Both mechanisms could combine to produce cell death. This study addresses a natural antibacterial clay from the NW Amazon basin, South America (AMZ clay). Clay mineralogy is composed of disordered kaolinite (28.9%), halloysite (17.8%) illite (12%) and smectite (16.7%). Mean particle size is 1.6μm and total and specific surface area 278.82 and 51.23 m2/g respectively. The pH of a suspension (200mg/ml) is 4.1 and its Eh is 361mV after 24h of equilibration. The ionic strength of the water in equilibrium with the clay after 24 h. is 6 x10-4M. These conditions, affect the element solubility, speciation, and interactions between clay and bacteria. Standard microbiological methods were used to assess the viability of two model bacteria (Escherichia coli and Bacillus subtilis) after incubation with clay at 37 degC for 24 hrs. A threefold reduction in bacterial viability was observed upon treatment with AMZ clay. We separated the cells from the clay using Nycodenz gradient media and observed the mounts under the TEM and SEM. Results showed several membrane anomalies and structural changes that were not observed in the control cells. Additionally, clay minerals appeared in some places attached to cell walls. Experiments showed that exchanging AMZ clay with KCl caused loss of antibacterial property. Among the exchangeable -and potentially toxic- ions we measured Al+3, Cu+2, Zn+2, Ba+2 and Co+2

  1. Mental Models in Social Interaction

    ERIC Educational Resources Information Center

    Fernandez-Berrocal, Pablo; Santamaria, Carlos

    2006-01-01

    In this study, the authors introduce a new way to analyze cognitive change during social interactions, based on the mental model theory of reasoning. From this approach, cognitive performance can be improved for solving problems that require multiple models when participants in a social interaction group maintain qualitatively different models of…

  2. Enhancing Learning through Human Computer Interaction

    ERIC Educational Resources Information Center

    McKay, Elspeth, Ed.

    2007-01-01

    Enhancing Learning Through Human Computer Interaction is an excellent reference source for human computer interaction (HCI) applications and designs. This "Premier Reference Source" provides a complete analysis of online business training programs and e-learning in the higher education sector. It describes a range of positive outcomes for linking…

  3. Enhancing Learning through Human Computer Interaction

    ERIC Educational Resources Information Center

    McKay, Elspeth, Ed.

    2007-01-01

    Enhancing Learning Through Human Computer Interaction is an excellent reference source for human computer interaction (HCI) applications and designs. This "Premier Reference Source" provides a complete analysis of online business training programs and e-learning in the higher education sector. It describes a range of positive outcomes for linking…

  4. Interaction Models for Functional Regression

    PubMed Central

    USSET, JOSEPH; STAICU, ANA-MARIA; MAITY, ARNAB

    2015-01-01

    A functional regression model with a scalar response and multiple functional predictors is proposed that accommodates two-way interactions in addition to their main effects. The proposed estimation procedure models the main effects using penalized regression splines, and the interaction effect by a tensor product basis. Extensions to generalized linear models and data observed on sparse grids or with measurement error are presented. A hypothesis testing procedure for the functional interaction effect is described. The proposed method can be easily implemented through existing software. Numerical studies show that fitting an additive model in the presence of interaction leads to both poor estimation performance and lost prediction power, while fitting an interaction model where there is in fact no interaction leads to negligible losses. The methodology is illustrated on the AneuRisk65 study data. PMID:26744549

  5. Human Lumbar Ligamentum Flavum Anatomy for Epidural Anesthesia: Reviewing a 3D MR-Based Interactive Model and Postmortem Samples.

    PubMed

    Reina, Miguel A; Lirk, Philipp; Puigdellívol-Sánchez, Anna; Mavar, Marija; Prats-Galino, Alberto

    2016-03-01

    The ligamentum flavum (LF) forms the anatomic basis for the loss-of-resistance technique essential to the performance of epidural anesthesia. However, the LF presents considerable interindividual variability, including the possibility of midline gaps, which may influence the performance of epidural anesthesia. We devise a method to reconstruct the anatomy of the digitally LF based on magnetic resonance images to clarify the exact limits and edges of LF and its different thickness, depending on the area examined, while avoiding destructive methods, as well as the dissection processes. Anatomic cadaveric cross sections enabled us to visually check the definition of the edges along the entire LF and compare them using 3D image reconstruction methods. Reconstruction was performed in images obtained from 7 patients. Images from 1 patient were used as a basis for the 3D spinal anatomy tool. In parallel, axial cuts, 2 to 3 cm thick, were performed in lumbar spines of 4 frozen cadavers. This technique allowed us to identify the entire ligament and its exact limits, while avoiding alterations resulting from cutting processes or from preparation methods. The LF extended between the laminas of adjacent vertebrae at all vertebral levels of the patients examined, but midline gaps are regularly encountered. These anatomical variants were reproduced in a 3D portable document format. The major anatomical features of the LF were reproduced in the 3D model. Details of its structure and variations of thickness in successive sagittal and axial slides could be visualized. Gaps within LF previously studied in cadavers have been identified in our interactive 3D model, which may help to understand their nature, as well as possible implications for epidural techniques.

  6. Experimental model for the investigation of kinetic and/or dynamic interactions between drugs and ethanol in humans.

    PubMed

    Hartmann, D; Flückiger, A; Ziegler, W H; Timm, U; Zell, M

    1988-04-01

    This study was performed to establish an experimental method for the investigation of interactions between ethanol and drugs under predictable and controlled conditions. The model was tested with flumazenil (Ro 15-1788), a short-acting benzodiazepine antagonist with an elimination half-life of 1 h. Six healthy volunteers (5 males, 1 female) were administered ethanol by intravenous infusion with stepwise changing rates. The infusion rates were adapted to each subject on the basis of individual disposition parameters of ethanol, which were derived from preceding short-term infusions of 120 min duration (1.0 mg/kg in males, 0.8 mg/kg in the female). This two-step procedure led to individual ethanol plasma levels between 1.47 +/- 0.04 and 1.71 +/- 0.03 g/L, which were reached after 2.5 h and thereafter maintained over another 6 h. Within the period of constant ethanol levels, single doses of flumazenil and placebo, respectively, were injected intravenously as a bolus (2 min) in a double-blind fashion according to a randomized two-way crossover design. Three subjects received a dose of 0.10 mg/kg of flumazenil, and the remaining three subjects received a dose of 0.20 mg/kg. Evaluation of the plasma concentration time curves of flumazenil did not reveal evidence of an effect of ethanol on the pharmacokinetics of this drug.

  7. Tuning of CD40-CD154 interactions in human B-lymphocyte activation: a broad array of in vitro models for a complex in vivo situation.

    PubMed

    Néron, Sonia; Nadeau, Philippe J; Darveau, André; Leblanc, Jean-François

    2011-02-01

    Naive and memory B-lymphocyte populations can be activated through the binding of CD154 to CD40, a receptor that is constitutively expressed on the surface of these cells. Models based on the in vitro stimulation of human B lymphocytes through CD40 have greatly contributed to our understanding of the human immune response in healthy individuals and patients suffering from immune disorders. The nature of the engineered CD40 ligands is as diverse as the in vitro models used in studies of CD40-activated B lymphocytes. Monoclonal anti-CD40 antibodies, recombinant CD154 proteins, soluble CD154(+) membranes as well as CD154(+) cell lines have turned out to be very useful tools, and are still in use today. As for any receptor-ligand interaction, parameters such as duration and strength of contact, timing, affinity, and receptor density are major determinants of CD40 binding by CD154 or anti-CD40. Furthermore, variation in the intensity of CD40 stimulation has been shown to influence proliferation, differentiation and immunoglobulin secretion of human hybridomas, B-cell lines, tonsil and blood B lymphocytes. The objective of this review is to present an overview of the great diversity of CD40 agonists used in in vitro models of B-lymphocyte activation, with a particular emphasis on variations in the resulting strength of CD40 signaling generated by these models. A better understanding of these models could open up new avenues for the rational use of human B lymphocytes as antigen-presenting cells in cellular therapies.

  8. Metalloprotein-inhibitor binding: Human carbonic anhydrase II as a model for probing metal-ligand interactions in a metalloprotein active site

    PubMed Central

    Martin, David P.; Hann, Zachary S.; Cohen, Seth M.

    2013-01-01

    An ever increasing number of metalloproteins are being discovered that play essential roles in physiological processes. Inhibitors of these proteins have significant potential for the treatment of human disease, but clinical success of these compounds has been limited. Herein, Zn(II)-dependent metalloprotein inhibitors in clinical use are reviewed, and the potential for using novel metal-binding groups (MBGs) in the design of these inhibitors is discussed. By using human carbonic anhydrase II (hCAII) as a model system, the nuances of MBG-metal interactions in the context of a protein environment can be probed. Understanding how metal coordination influences inhibitor binding may help in the design new therapeutics targeting metalloproteins. PMID:23706138

  9. Human-robot interaction modeling and simulation of supervisory control and situational awareness during field experimentation with military manned and unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Johnson, Tony; Metcalfe, Jason; Brewster, Benjamin; Manteuffel, Christopher; Jaswa, Matthew; Tierney, Terrance

    2010-04-01

    The proliferation of intelligent systems in today's military demands increased focus on the optimization of human-robot interactions. Traditional studies in this domain involve large-scale field tests that require humans to operate semiautomated systems under varying conditions within military-relevant scenarios. However, provided that adequate constraints are employed, modeling and simulation can be a cost-effective alternative and supplement. The current presentation discusses a simulation effort that was executed in parallel with a field test with Soldiers operating military vehicles in an environment that represented key elements of the true operational context. In this study, "constructive" human operators were designed to represent average Soldiers executing supervisory control over an intelligent ground system. The constructive Soldiers were simulated performing the same tasks as those performed by real Soldiers during a directly analogous field test. Exercising the models in a high-fidelity virtual environment provided predictive results that represented actual performance in certain aspects, such as situational awareness, but diverged in others. These findings largely reflected the quality of modeling assumptions used to design behaviors and the quality of information available on which to articulate principles of operation. Ultimately, predictive analyses partially supported expectations, with deficiencies explicable via Soldier surveys, experimenter observations, and previously-identified knowledge gaps.

  10. Modeling of Human Prokineticin Receptors: Interactions with Novel Small-Molecule Binders and Potential Off-Target Drugs

    PubMed Central

    Levit, Anat; Yarnitzky, Talia; Wiener, Ayana; Meidan, Rina; Niv, Masha Y.

    2011-01-01

    Background and Motivation The Prokineticin receptor (PKR) 1 and 2 subtypes are novel members of family A GPCRs, which exhibit an unusually high degree of sequence similarity. Prokineticins (PKs), their cognate ligands, are small secreted proteins of ∼80 amino acids; however, non-peptidic low-molecular weight antagonists have also been identified. PKs and their receptors play important roles under various physiological conditions such as maintaining circadian rhythm and pain perception, as well as regulating angiogenesis and modulating immunity. Identifying binding sites for known antagonists and for additional potential binders will facilitate studying and regulating these novel receptors. Blocking PKRs may serve as a therapeutic tool for various diseases, including acute pain, inflammation and cancer. Methods and Results Ligand-based pharmacophore models were derived from known antagonists, and virtual screening performed on the DrugBank dataset identified potential human PKR (hPKR) ligands with novel scaffolds. Interestingly, these included several HIV protease inhibitors for which endothelial cell dysfunction is a documented side effect. Our results suggest that the side effects might be due to inhibition of the PKR signaling pathway. Docking of known binders to a 3D homology model of hPKR1 is in agreement with the well-established canonical TM-bundle binding site of family A GPCRs. Furthermore, the docking results highlight residues that may form specific contacts with the ligands. These contacts provide structural explanation for the importance of several chemical features that were obtained from the structure-activity analysis of known binders. With the exception of a single loop residue that might be perused in the future for obtaining subtype-specific regulation, the results suggest an identical TM-bundle binding site for hPKR1 and hPKR2. In addition, analysis of the intracellular regions highlights variable regions that may provide subtype specificity

  11. Mesoscopic modelling of the interaction of infrared lasers with composite materials: an application to human dental enamel

    NASA Astrophysics Data System (ADS)

    Vila Verde, A.; Ramos, Marta M. D.; Stoneham, Marshall; Mendes Ribeiro, R.

    2004-11-01

    The mesostructure and composition of composite materials determine their mechanical, optical and thermal properties and, consequently, their response to incident radiation. We have developed general finite element models of porous composite materials under infrared radiation to examine the influence of pore size on one of the determining parameters of the stress distribution in the material: the temperature distribution. We apply them to the specific case of human dental enamel, a material which has nanometer scale pores containing water/organic, and predict the maximum temperature reached after a single 0.35 μs laser pulse of sub-ablative fluence by two lasers: Er:YAG (2.9 μm) and CO2 (10.6 μm). For the Er:YAG laser, the results imply a strong dependence of the maximum temperature reached at the pore on the area-to-volume ratio of the pore, whereas there is little such dependence for CO2 lasers. Thus, CO2 lasers may produce more reproducible results than Er:YAG lasers when it comes to enamel ablation, which may be of significant interest during clinical practice. More generally, when ablating composite materials by infrared lasers researchers should account for the material's microstructure and composition when designing experiments or interpreting results, since a more simplistic continuum approach may not be sufficient to explain differences observed during ablation of materials with similar optical properties or of the same material but using different wavelengths.

  12. [Human skin reconstructed in vitro as a model to study the keratinocyte, the fibroblast and their interactions: photodamage and repair processes].

    PubMed

    Bernerd, Françoise

    2005-01-01

    The protective role of the skin is provided by the two major compartments of the skin, dermis and epidermis. Both are affected in the long term by consequences of sun exposure such as skin photoaging and cancer development. Characterization of UV-induced skin response at cellular and molecular levels is needed for prevention or correction of these long term effects. The human skin reconstructed in vitro, comprising both a living dermal equivalent and a fully differentiated epidermis represents a predictive tool to characterize wavelength and cell type specific biological damage together with tissular distribution. While UVB directly affects epidermis, inducing DNA lesions and apoptotic sunburn keratinocytes, UVA radiation can directly target the dermal compartment through ROS generation, dermal fibroblasts alterations and extracellular matrix (ECM) modifications. Interactions between the two compartments have also been found, especially for MMP1 induction. In the normal population, photodamage can be repaired through specialized systems. Using skin cells from Xeroderma pigmentosum (XP, a photosensitive and cancer-prone disease), a DNA-repair deficient skin has been developed in vitro. Specific features due to intrinsic XP cell phenotype have been discovered, some of them being indicative of early steps of neoplasia and suggesting a particular role for stroma-epithelium interactions. Finally, human reconstructed skin can be used for approaches designed to regenerate photodamaged skin. The dermal-epidermal junction (DEJ), which is crucial for skin cohesion, is drastically altered in photo-aged skin. The three-dimensional skin model allowed to visualize the improving effects of vitamin C on the DEJ. Modified skin models, lacking one cell type, allowed us to determine the cellular origin of the different markers, their spatial localization, and the respective roles and interactions of keratinocytes and fibroblasts during DEJ formation. All together these studies give a

  13. An overview of human-computer interaction.

    PubMed

    Beaudouin-Lafon, M

    1993-01-01

    This article presents an overview of the field of human-computer interaction. This branch of computer science concerns the design, implementation and analysis of interactive computer systems. We show that this field is multidisciplinary in essence, involving social scientists as well as computer scientists, experts of application domains, graphics designers, etc. Once the fundamental aspects of human-computer interaction are presented, we take a practical approach in order to introduce the methods, tools and techniques that are available today for the design and implementation of interactive computer systems. Finally, we present the main directions of research in this domain.

  14. Three-dimensional modelling of human cytochrome P450 1A2 and its interaction with caffeine and MeIQ

    NASA Astrophysics Data System (ADS)

    Lozano, J. J.; López-de-Briñas, E.; Centeno, N. B.; Guigó, R.; Sanz, F.

    1997-07-01

    The three-dimensional modelling of proteins is a useful tool to fill the gap between the number of sequenced proteins and the number of experimentally known 3D structures. However, when the degree of homology between the protein and the available 3D templates is low, model building becomes a difficult task and the reliability of the results depends critically on the correctness of the sequence alignment. For this reason, we have undertaken the modelling of human cytochrome P450 1A2 starting by a careful analysis of several sequence alignment strategies (multiple sequence alignments and the TOPITS threading technique). The best results were obtained using TOPITS followed by a manual refinement to avoid unlikely gaps. Because TOPITS uses secondary structure predictions, several methods that are available for this purpose (Levin, Gibrat, DPM, NnPredict, PHD, SOPM and NNSP) have also been evaluated on cytochromes P450 with known 3D structures. More reliable predictions on α-helices have been obtained with PHD, which is the method implemented in TOPITS. Thus, a 3D model for human cytochrome P450 1A2 has been built using the known crystal coordinates of P450 BM3 as the template. The model was refined using molecular mechanics computations. The model obtained shows a consistent location of the substrate recognition segments previously postulated for the CYP2 family members. The interaction of caffeine and a carcinogenic aromatic amine (MeIQ), which are characteristic P450 1A2 substrates, has been investigated. The substrates were solvated taking into account their molecular electrostatic potential distributions. The docking of the solvated substrates in the active site of the model was explored with the AUTODOCK programme, followed by molecular mechanics optimisation of the most interesting complexes. Stable complexes were obtained that could explain the oxidation of the considered substrates by cytochrome P450 1A2 and could offer an insight into the role played by water

  15. The use of HepaRG and human hepatocyte data in predicting CYP induction drug-drug interactions via static equation and dynamic mechanistic modelling approaches.

    PubMed

    Grime, Ken; Ferguson, Douglas D; Riley, Robert J

    2010-12-01

    The method of predicting CYP induction drug-drug interactions (DDIs) from a relative induction score (RIS) calibration has been developed to provide a novel model facilitating predictions for any CYP-inducer substrate combination by inclusion of parameters such as the fraction of hepatic clearance mediated by a specific CYP and fraction of the dose escaping intestinal extraction. In vitro HepaRG CYP3A4 induction data were used as a basis for the approach and a large number of DDIs were well predicted. Primary human hepatocyte data were also used to make predictions, using the HepaRG calibration as a foundation. Similar predictive accuracy suggests that HepaRG and primary hepatocyte data can be used inter-changeably within the same laboratory. A comparison of this 'indirect' calibration method with a direct in vitro-in vivo scaling approach was made and investigations undertaken to define the most appropriate in vivo inducer concentration to use. Additionally, a reasonably effective prediction model based on F(2) (the concentration of inducer taken to increase the CYP mRNA 2-fold above background) was established. An accurate prediction for the CYP1A2-dependent omeprazole-caffeine interaction was also made, demonstrating that the methods are useful for the evaluation of DDIs from induction involving mechanisms other than PXR activation. Finally, a dynamic mechanistic model accounting for the simultaneous influence of CYP induction and reversible and irreversible CYP inhibition in both the liver and intestine was written to provide a prediction of the overall DDI when several interactions occur concurrently. The rationale for using the various models described, alongside commercially available prediction tools, at various stages of the drug discovery process is described.

  16. Human-Computer Interaction and Virtual Environments

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler)

    1995-01-01

    The proceedings of the Workshop on Human-Computer Interaction and Virtual Environments are presented along with a list of attendees. The objectives of the workshop were to assess the state-of-technology and level of maturity of several areas in human-computer interaction and to provide guidelines for focused future research leading to effective use of these facilities in the design/fabrication and operation of future high-performance engineering systems.

  17. New activity pattern in human interactive dynamics

    NASA Astrophysics Data System (ADS)

    Formentin, Marco; Lovison, Alberto; Maritan, Amos; Zanzotto, Giovanni

    2015-09-01

    We investigate the response function of human agents as demonstrated by written correspondence, uncovering a new pattern for how the reactive dynamics of individuals is distributed across the set of each agent’s contacts. In long-term empirical data on email, we find that the set of response times considered separately for the messages to each different correspondent of a given writer, generate a family of heavy-tailed distributions, which have largely the same features for all agents, and whose characteristic times grow exponentially with the rank of each correspondent. We furthermore show that this new behavioral pattern emerges robustly by considering weighted moving averages of the priority-conditioned response-time probabilities generated by a basic prioritization model. Our findings clarify how the range of priorities in the inputs from one’s environment underpin and shape the dynamics of agents embedded in a net of reactive relations. These newly revealed activity patterns might be universal, being present in other general interactive environments, and constrain future models of communication and interaction networks, affecting their architecture and evolution.

  18. Human-Computer Interaction. Second Edition.

    ERIC Educational Resources Information Center

    Dix, Alan J.; Finlay, Janet E.; Abowd, Gregory D.; Beale, Russell

    This book examines human-computer interaction (HCI), with a focus on designing computer technology to be more usable by people. The book provides a multi-disciplinary approach to the subject through a synthesis of computer science, cognitive science, psychology, and sociology, and stresses a principled approach to interactive systems design that…

  19. Human-Computer Interaction. Second Edition.

    ERIC Educational Resources Information Center

    Dix, Alan J.; Finlay, Janet E.; Abowd, Gregory D.; Beale, Russell

    This book examines human-computer interaction (HCI), with a focus on designing computer technology to be more usable by people. The book provides a multi-disciplinary approach to the subject through a synthesis of computer science, cognitive science, psychology, and sociology, and stresses a principled approach to interactive systems design that…

  20. The human dynamic clamp as a paradigm for social interaction.

    PubMed

    Dumas, Guillaume; de Guzman, Gonzalo C; Tognoli, Emmanuelle; Kelso, J A Scott

    2014-09-02

    Social neuroscience has called for new experimental paradigms aimed toward real-time interactions. A distinctive feature of interactions is mutual information exchange: One member of a pair changes in response to the other while simultaneously producing actions that alter the other. Combining mathematical and neurophysiological methods, we introduce a paradigm called the human dynamic clamp (HDC), to directly manipulate the interaction or coupling between a human and a surrogate constructed to behave like a human. Inspired by the dynamic clamp used so productively in cellular neuroscience, the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject's own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual "teacher." We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof.

  1. Creating Interactive Virtual Humans: Some Assembly Required

    DTIC Science & Technology

    2002-08-01

    the synthetic environment. For example, Mr. Bubb of Zoesis Studios (see Figure 5) is tightly responsive to unpredictable and con- tinuous changes in...other alterna- tives is an important open problem in vir- tual human research. The future of androids remains to be seen, but realistic interactive...computer.org/intelligent 61 Figure 5. Mr. Bubb is an interactive character developed by Zoesis Studios that reacts continously to the user’s social interactions

  2. Human-Computer Interaction in Smart Environments

    PubMed Central

    Paravati, Gianluca; Gatteschi, Valentina

    2015-01-01

    Here, we provide an overview of the content of the Special Issue on “Human-computer interaction in smart environments”. The aim of this Special Issue is to highlight technologies and solutions encompassing the use of mass-market sensors in current and emerging applications for interacting with Smart Environments. Selected papers address this topic by analyzing different interaction modalities, including hand/body gestures, face recognition, gaze/eye tracking, biosignal analysis, speech and activity recognition, and related issues.

  3. The Science of Human Interaction and Teaching

    ERIC Educational Resources Information Center

    Yano, Kazuo

    2013-01-01

    There is a missing link between our understanding of teaching as high-level social phenomenon and teaching as a physiological phenomenon of brain activity. We suggest that the science of human interaction is the missing link. Using over one-million days of human-behavior data, we have discovered that "collective activenes" (CA), which indicates…

  4. The Science of Human Interaction and Teaching

    ERIC Educational Resources Information Center

    Yano, Kazuo

    2013-01-01

    There is a missing link between our understanding of teaching as high-level social phenomenon and teaching as a physiological phenomenon of brain activity. We suggest that the science of human interaction is the missing link. Using over one-million days of human-behavior data, we have discovered that "collective activenes" (CA), which indicates…

  5. Computing the stresses and deformations of the human eye components due to a high explosive detonation using fluid-structure interaction model.

    PubMed

    Karimi, Alireza; Razaghi, Reza; Navidbakhsh, Mahdi; Sera, Toshihiro; Kudo, Susumu

    2016-05-01

    In spite the fact that a very small human body surface area is comprised by the eye, its wounds due to detonation have recently been dramatically amplified. Although many efforts have been devoted to measure injury of the globe, there is still a lack of knowledge on the injury mechanism due to Primary Blast Wave (PBW). The goal of this study was to determine the stresses and deformations of the human eye components, including the cornea, aqueous, iris, ciliary body, lens, vitreous, retina, sclera, optic nerve, and muscles, attributed to PBW induced by trinitrotoluene (TNT) explosion via a Lagrangian-Eulerian computational coupling model. Magnetic Resonance Imaging (MRI) was employed to establish a Finite Element (FE) model of the human eye according to a normal human eye. The solid components of the eye were modelled as Lagrangian mesh, while an explosive TNT, air domain, and aqueous were modelled using Arbitrary Lagrangian-Eulerian (ALE) mesh. Nonlinear dynamic FE simulations were accomplished using the explicit FE code, namely LS-DYNA. In order to simulate the blast wave generation, propagation, and interaction with the eye, the ALE formulation with Jones-Wilkins-Lee (JWL) equation defining the explosive material were employed. The results revealed a peak stress of 135.70kPa brought about by detonation upsurge on the cornea at the distance of 25cm. The highest von Mises stresses were observed on the sclera (267.3kPa), whereas the lowest one was seen on the vitreous body (0.002kPa). The results also showed a relatively high resultant displacement for the macula as well as a high variation for the radius of curvature for the cornea and lens, which can result in both macular holes, optic nerve damage and, consequently, vision loss. These results may have implications not only for understanding the value of stresses and strains in the human eye components but also giving an outlook about the process of PBW triggers damage to the eye. Copyright © 2016 Elsevier Ltd

  6. Molecular modelling of the differential interaction between several non-steroidal anti-inflammatory drugs and human prostaglandin endoperoxide H synthase-2 (h-PGHS-2).

    PubMed

    Pouplana, R; Lozano, J J; Ruiz, J

    2002-01-01

    The prostaglandin endoperoxide H synthase-1 (PGHS-1) and prostaglandin endoperoxide H synthase-2 (PGHS-2) are the targets of non-steroidal anti-inflammatory drugs (NSAIDs). The high degree of selectivity for inhibition of PGHS-2 shown by certain compounds appears to stem from two mechanisms (time-dependent, time-independent inhibition) by which they interact with each isoform. Molecular models of the complexes between indomethacin, fenamates, 2-phenylpropionic acids and the selective cyclooxygenase-2 (COX-2) inhibitors, with the cyclooxygenase active site of human PGHS-2 have been built by combining homology modelling, conformational searching and automated docking techniques. The stability of the resulting complexes has been assessed by molecular dynamics simulations combined with extended linear response calculations. The results allow us to identify regions of biological significance consistent with both X-ray crystallographic and kinetic results. The selective PGHS-2 inhibitors exploit the extra space of a side-pocket in the active site of PGHS-2 that is not found in PGHS-1. The results obtained point out a marked relationship between the experimental affinity and the electrostatic interaction energy alone for a series of NSAIDs. Analysis of the structural and the energetic data provides evidence supporting that network of hydrogen bonds between Tyr355, Glu524, Arg120 and Arg513 might be involved in mediating the binding of the time-dependent inhibitors of PGHS-2.

  7. Prosodic alignment in human-computer interaction

    NASA Astrophysics Data System (ADS)

    Suzuki, N.; Katagiri, Y.

    2007-06-01

    Androids that replicate humans in form also need to replicate them in behaviour to achieve a high level of believability or lifelikeness. We explore the minimal social cues that can induce in people the human tendency for social acceptance, or ethopoeia, toward artifacts, including androids. It has been observed that people exhibit a strong tendency to adjust to each other, through a number of speech and language features in human-human conversational interactions, to obtain communication efficiency and emotional engagement. We investigate in this paper the phenomena related to prosodic alignment in human-computer interactions, with particular focus on human-computer alignment of speech characteristics. We found that people exhibit unidirectional and spontaneous short-term alignment of loudness and response latency in their speech in response to computer-generated speech. We believe this phenomenon of prosodic alignment provides one of the key components for building social acceptance of androids.

  8. Measurement error models with interactions.

    PubMed

    Midthune, Douglas; Carroll, Raymond J; Freedman, Laurence S; Kipnis, Victor

    2016-04-01

    An important use of measurement error models is to correct regression models for bias due to covariate measurement error. Most measurement error models assume that the observed error-prone covariate (WW ) is a linear function of the unobserved true covariate (X) plus other covariates (Z) in the regression model. In this paper, we consider models for W that include interactions between X and Z. We derive the conditional distribution of X given W and Z and use it to extend the method of regression calibration to this class of measurement error models. We apply the model to dietary data and test whether self-reported dietary intake includes an interaction between true intake and body mass index. We also perform simulations to compare the model to simpler approximate calibration models. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  9. Modeling Interactive Intelligences

    DTIC Science & Technology

    2002-08-01

    New York: Basic Books, 1999. P. 207-10. [5] Piaget , Jean . Play, Dreams, and Imitation in Childhood. New York: Norton, 1962. [6] Dillard, Annie. Living...concepts of reentry and binding. Next, I rely on Jean Piaget’s model of adaptation in order to examine the function of imitation and play in an...rather than metrics should be used. 2. ADAPTATION, SELECTION, IMITATION, AND PLAY Piaget presented adaptive behavior as a combination of accommodation and

  10. Past Holocene soil erosion modeling as a new way to decipher human-climate-environment interactions on natural geo-ecosystem over long time-scale.

    NASA Astrophysics Data System (ADS)

    Simonneau, Anaëlle; Di Giovanni, Christian; Chapron, Emmanuel

    2017-04-01

    Soil erosion is a global phenomenon dealing with both environmental, societal and economic issues. Soil erosion is also one of the key processes when it is a matter of Human-climate-environment interactions [1, 2] since if mechanical erosion of continental surfaces initially results from climatic forcing, it can be largely amplified by anthropogenic activities. Using multi-scalar datasets to model long-term (Holocene) erosion fluxes in contrasted areas, where human pressure is well documented by geoarchaeology, we address how landscape evolution, geomorphological processes, ecosystem response and human impacts have been connected over time. Beyond that, such interdisciplinary and integrative approach allow (1) to locally date, qualify, and in particular quantify, both climate variability (rainfall) and impacts of human activities on soils, and (2) to discuss of potential feedback mechanisms and the legacy of past socio-cultural systems on actual geo-ecosystems. Lacustrine sediment represents one of the more relevant natural archives in order to reconstruct environmental or climatic variability and human activities over the past thousand years. Over the last 50 years, the edges of lakes Paladru (low altitude site, 640 m a.s.l.) and Blanc Huez (high-altitude site, 2250 m a.s.l.), both located in Western French Alps and therefore sensitive to the same climatic influences, have been deeply studied by archaeologists who documented and dated periods of enhanced human pressures (agriculture, mining [3, 4]). In these two case-studies, we were therefore able to confront the specific calendars of local human activities with past landscape evolution (vegetation cover, 5) and soil erosion fluxes reconstituted from specific organic tracers quantified into the lacustrine sediments [3, 6]. Results demonstrated that, over the Holocene, climatic forcing, and more particularly glacial fluctuations, influenced human accessibility to high-altitude sites (lake Blanc Huez) and therefore

  11. Human-Robot Interaction: Status and Challenges.

    PubMed

    Sheridan, Thomas B

    2016-06-01

    The current status of human-robot interaction (HRI) is reviewed, and key current research challenges for the human factors community are described. Robots have evolved from continuous human-controlled master-slave servomechanisms for handling nuclear waste to a broad range of robots incorporating artificial intelligence for many applications and under human supervisory control. This mini-review describes HRI developments in four application areas and what are the challenges for human factors research. In addition to a plethora of research papers, evidence of success is manifest in live demonstrations of robot capability under various forms of human control. HRI is a rapidly evolving field. Specialized robots under human teleoperation have proven successful in hazardous environments and medical application, as have specialized telerobots under human supervisory control for space and repetitive industrial tasks. Research in areas of self-driving cars, intimate collaboration with humans in manipulation tasks, human control of humanoid robots for hazardous environments, and social interaction with robots is at initial stages. The efficacy of humanoid general-purpose robots has yet to be proven. HRI is now applied in almost all robot tasks, including manufacturing, space, aviation, undersea, surgery, rehabilitation, agriculture, education, package fetch and delivery, policing, and military operations. © 2016, Human Factors and Ergonomics Society.

  12. A 3D in vitro model of the human breast duct: a method to unravel myoepithelial-luminal interactions in the progression of breast cancer.

    PubMed

    Carter, Edward P; Gopsill, James A; Gomm, Jennifer J; Jones, J Louise; Grose, Richard P

    2017-04-21

    3D modelling fulfils a critical role in research, allowing for complex cell behaviour and interactions to be studied in physiomimetic conditions. With tissue banks becoming established for a number of cancers, researchers now have access to primary patient cells, providing the perfect building blocks to recreate and interrogate intricate cellular systems in the laboratory. The ducts of the human breast are composed of an inner layer of luminal cells supported by an outer layer of myoepithelial cells. In early-stage ductal carcinoma in situ, cancerous luminal cells are confined to the ductal space by an intact myoepithelial layer. Understanding the relationship between myoepithelial and luminal cells in the development of cancer is critical for the development of new therapies and prognostic markers. This requires the generation of new models that allows for the manipulation of these two cell types in a physiological setting. Using access to the Breast Cancer Now Tissue Bank, we isolated pure populations of myoepithelial and luminal cells from human reduction mammoplasty specimens and placed them into 2D culture. These cells were infected with lentiviral particles encoding either fluorescent proteins, to facilitate cell tracking, or an inducible human epidermal growth factor receptor 2 (HER2) expression construct. Myoepithelial and luminal cells were then recombined in collagen gels, and the resulting cellular structures were analysed by confocal microscopy. RESULTS: Myoepithelial and luminal cells isolated from reduction mammoplasty specimens can be grown separately in 2D culture and retain their differentiated state. When recombined in collagen gels, these cells reform into physiologically reflective bilayer structures. Inducible expression of HER2 in the luminal compartment, once the bilayer has formed, leads to robust luminal filling, recapitulating ductal carcinoma in situ, and can be blocked with anti-HER2 therapies. This model allows for the interaction

  13. Bridging the Gap - Interactive Inverse Groundwater Modeling

    NASA Astrophysics Data System (ADS)

    Singh, A.; Minsker, B.

    2005-12-01

    This paper presents a novel approach for solving the inverse problem of estimating heterogeneous aquifer parameters for a groundwater flow model, using interactive multi-objective evolutionary optimization. A hypothetical aquifer, for which the `true' parameter values (in this case hydraulic conductivity) are known, is used as a test case to demonstrate the usefulness of this method. It is shown that using automated calibration techniques without using expert interaction leads to parameter values that are not consistent with site knowledge. In such cases, it is desirable to incorporate expert knowledge in the inversion process to generate more reasonable estimates. An interactive approach is proposed within a multi-objective framework that allows the user to evaluate trade-offs between the expert knowledge and other measures of numerical errors. Using Pilot points and geostatistical parameters as decision variables, numerical optimization is combined with expert knowledge leading to conductivity fields that respect both the observation data and site knowledge that the expert may have. Early results indicate that this approach leads to parameter estimates that are much more consistent with site knowledge. A major issue with interactive approaches, however, is `human fatigue' in evaluating numerous potential solutions. One way of dealing with human fatigue is to use machine learning to model user preferences. This work presents initial results showing that machine learning models can be successfully used to augment user interaction, allowing the interactive genetic algorithm to find good solutions with much less user-effort.

  14. Language evolution and human-computer interaction

    NASA Technical Reports Server (NTRS)

    Grudin, Jonathan; Norman, Donald A.

    1991-01-01

    Many of the issues that confront designers of interactive computer systems also appear in natural language evolution. Natural languages and human-computer interfaces share as their primary mission the support of extended 'dialogues' between responsive entities. Because in each case one participant is a human being, some of the pressures operating on natural languages, causing them to evolve in order to better support such dialogue, also operate on human-computer 'languages' or interfaces. This does not necessarily push interfaces in the direction of natural language - since one entity in this dialogue is not a human, this is not to be expected. Nonetheless, by discerning where the pressures that guide natural language evolution also appear in human-computer interaction, we can contribute to the design of computer systems and obtain a new perspective on natural languages.

  15. Language evolution and human-computer interaction

    NASA Technical Reports Server (NTRS)

    Grudin, Jonathan; Norman, Donald A.

    1991-01-01

    Many of the issues that confront designers of interactive computer systems also appear in natural language evolution. Natural languages and human-computer interfaces share as their primary mission the support of extended 'dialogues' between responsive entities. Because in each case one participant is a human being, some of the pressures operating on natural languages, causing them to evolve in order to better support such dialogue, also operate on human-computer 'languages' or interfaces. This does not necessarily push interfaces in the direction of natural language - since one entity in this dialogue is not a human, this is not to be expected. Nonetheless, by discerning where the pressures that guide natural language evolution also appear in human-computer interaction, we can contribute to the design of computer systems and obtain a new perspective on natural languages.

  16. Interactive Model-Centric Systems Engineering (IMCSE) Phase Two

    DTIC Science & Technology

    2015-02-28

    point in time by a single decision maker; multi- sensory representations may allow for some loosening of this constraint and improve human -model...important in the practice of SE. To take advantage of model-based techniques, it is important to improve human and technology integration. The...research program aims to develop transformative results through enabling intense human -model interaction, to rapidly conceive of systems and interact

  17. Multimodal interaction for human-robot teams

    NASA Astrophysics Data System (ADS)

    Burke, Dustin; Schurr, Nathan; Ayers, Jeanine; Rousseau, Jeff; Fertitta, John; Carlin, Alan; Dumond, Danielle

    2013-05-01

    Unmanned ground vehicles have the potential for supporting small dismounted teams in mapping facilities, maintaining security in cleared buildings, and extending the team's reconnaissance and persistent surveillance capability. In order for such autonomous systems to integrate with the team, we must move beyond current interaction methods using heads-down teleoperation which require intensive human attention and affect the human operator's ability to maintain local situational awareness and ensure their own safety. This paper focuses on the design, development and demonstration of a multimodal interaction system that incorporates naturalistic human gestures, voice commands, and a tablet interface. By providing multiple, partially redundant interaction modes, our system degrades gracefully in complex environments and enables the human operator to robustly select the most suitable interaction method given the situational demands. For instance, the human can silently use arm and hand gestures for commanding a team of robots when it is important to maintain stealth. The tablet interface provides an overhead situational map allowing waypoint-based navigation for multiple ground robots in beyond-line-of-sight conditions. Using lightweight, wearable motion sensing hardware either worn comfortably beneath the operator's clothing or integrated within their uniform, our non-vision-based approach enables an accurate, continuous gesture recognition capability without line-of-sight constraints. To reduce the training necessary to operate the system, we designed the interactions around familiar arm and hand gestures.

  18. Attitudes, Learning and Human-Computer Interaction: An Application of the Fishbein and Ajzen Model of Attitude-Behavior Consistency.

    ERIC Educational Resources Information Center

    Yeaman, Andrew R. J.

    The Fishbein and Ajzen model of attitude-behavior consistency was applied to 56 undergraduates learning to use a microcomputer. Two levels of context for this act were compared: the students' beliefs about themselves, and their beliefs about people in general. The results indicated that students' beliefs were good predictors of their behavioral…

  19. Toward the modeling of mucus draining from human lung: role of airways deformation on air-mucus interaction

    PubMed Central

    Mauroy, Benjamin; Flaud, Patrice; Pelca, Dominique; Fausser, Christian; Merckx, Jacques; Mitchell, Barrett R.

    2015-01-01

    Chest physiotherapy is an empirical technique used to help secretions to get out of the lung whenever stagnation occurs. Although commonly used, little is known about the inner mechanisms of chest physiotherapy and controversies about its use are coming out regularly. Thus, a scientific validation of chest physiotherapy is needed to evaluate its effects on secretions. We setup a quasi-static numerical model of chest physiotherapy based on thorax and lung physiology and on their respective biophysics. We modeled the lung with an idealized deformable symmetric bifurcating tree. Bronchi and their inner fluids mechanics are assumed axisymmetric. Static data from the literature is used to build a model for the lung's mechanics. Secretions motion is the consequence of the shear constraints apply by the air flow. The input of the model is the pressure on the chest wall at each time, and the output is the bronchi geometry and air and secretions properties. In the limit of our model, we mimicked manual and mechanical chest physiotherapy techniques. We show that for secretions to move, air flow has to be high enough to overcome secretion resistance to motion. Moreover, the higher the pressure or the quicker it is applied, the higher is the air flow and thus the mobilization of secretions. However, pressures too high are efficient up to a point where airways compressions prevents air flow to increase any further. Generally, the first effects of manipulations is a decrease of the airway tree hydrodynamic resistance, thus improving ventilation even if secretions do not get out of the lungs. Also, some secretions might be pushed deeper into the lungs; this effect is stronger for high pressures and for mechanical chest physiotherapy. Finally, we propose and tested two a dimensional numbers that depend on lung properties and that allow to measure the efficiency and comfort of a manipulation. PMID:26300780

  20. The Effect of Affect: Modeling the Impact of Emotional State on the Behavior of Interactive Virtual Humans

    DTIC Science & Technology

    2001-01-01

    a more general integration that goes beyond that implementation. 3. RELATED WORK Several researchers have considered computational models of emo...State Our primary design goal is to create general mechanisms that are not tied to the details of any specific domain. Thus, emotional ap- praisals do...appraisals are triggered reflexively by changes in an agent’s mental representations, which are in turn changed by general reasoning mechanisms. External

  1. Management Education: Reflective Learning on Human Interaction

    ERIC Educational Resources Information Center

    Clydesdale, Greg

    2016-01-01

    Purpose: This paper aims to describe an attempt to develop a more effective technique to teach self-awareness and relationship skills. Design/methodology/approach: A journal is used in combination with a model of human nature. The model lists human characteristics that the management trainee must identify in themselves and others they interact…

  2. Management Education: Reflective Learning on Human Interaction

    ERIC Educational Resources Information Center

    Clydesdale, Greg

    2016-01-01

    Purpose: This paper aims to describe an attempt to develop a more effective technique to teach self-awareness and relationship skills. Design/methodology/approach: A journal is used in combination with a model of human nature. The model lists human characteristics that the management trainee must identify in themselves and others they interact…

  3. Analysis of human emotion in human-robot interaction

    NASA Astrophysics Data System (ADS)

    Blar, Noraidah; Jafar, Fairul Azni; Abdullah, Nurhidayu; Muhammad, Mohd Nazrin; Kassim, Anuar Muhamed

    2015-05-01

    There is vast application of robots in human's works such as in industry, hospital, etc. Therefore, it is believed that human and robot can have a good collaboration to achieve an optimum result of work. The objectives of this project is to analyze human-robot collaboration and to understand humans feeling (kansei factors) when dealing with robot that robot should adapt to understand the humans' feeling. Researches currently are exploring in the area of human-robot interaction with the intention to reduce problems that subsist in today's civilization. Study had found that to make a good interaction between human and robot, first it is need to understand the abilities of each. Kansei Engineering in robotic was used to undergo the project. The project experiments were held by distributing questionnaire to students and technician. After that, the questionnaire results were analyzed by using SPSS analysis. Results from the analysis shown that there are five feelings which significant to the human in the human-robot interaction; anxious, fatigue, relaxed, peaceful, and impressed.

  4. Antibody-antigenic peptide interactions monitored by SPR and QCM-D. A model for SPR detection of IA-2 autoantibodies in human serum.

    PubMed

    Ayela, Cedric; Roquet, Francoise; Valera, Lionel; Granier, Claude; Nicu, Liviu; Pugnière, Martine

    2007-06-15

    This work reports on a complementary use of surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation monitoring (QCM-D) technologies to study interactions between a peptide antigen and polyclonal antibodies, in an experimental format suitable for diagnostic assays of autoimmune diseases. In the chosen model, a synthetic peptide from the juxtamembrane region of IA-2 (a type 1 diabetes associated antigen) was immobilized by an optimized chemical protocol applicable to both BIACORE and QCM-D sensors. A thorough study of the peptide immobilization was performed to optimize the signal-to-noise ratio using mixed self-assembled monolayers (SAM) on a gold surface. Introduction of polyethylene glycol (EG(6)) chains into mixed SAM layers and addition of an anionic surfactant to the human serum reduced non-specific binding without modifying the viscoelasticity properties of the layer. Under our conditions, the antibody SPR detection limit was determined to be 0.2 nM in diluted human serum. This value is in agreement with the reported rank distribution of IA-2 antibodies in diabetic patient sera. Label-free and real-time technologies such as SPR and/or QCM-D could be precious tools in future diagnostic assays.

  5. In vitro susceptibility of T lymphocytes from chimpanzees (Pan troglodytes) to human herpesvirus 6 (HHV-6): a potential animal model to study the interaction between HHV-6 and human immunodeficiency virus type 1 in vivo.

    PubMed Central

    Lusso, P; Markham, P D; DeRocco, S E; Gallo, R C

    1990-01-01

    The in vitro susceptibility of several nonhuman primate species to human herpesvirus 6 (HHV-6) was investigated. Only peripheral blood mononuclear cells from chimpanzees (Pan troglodytes) were found permissive to productive infection by HHV-6, indicating that the host range of HHV-6, albeit limited, may not be restricted to Homo sapiens. However, natural HHV-6 infection in chimpanzees, as well as in the other species tested, could not be documented by serological analysis. As previously observed with human cells, HHV-6 infection of chimpanzee peripheral blood mononuclear cells was highly cytopathic and the infected cells exhibited phenotypic features of activated T lymphocytes. Although in humans the majority of HHV-6-infected lymphocytes displayed the CD4 antigen, in chimpanzees a mixed CD4+ and CD8+ phenotype was observed. HHV-6 was also shown to productively coinfect individual chimpanzee T cells with human immunodeficiency virus type 1, resulting in an accelerated induction of cytopathicity. In light of these findings, we propose the utilization of chimpanzees as a potential animal model system to investigate the in vivo interaction between HHV-6 and human immunodeficiency virus type 1 and its relevance to the development of acquired immune deficiency syndrome. Images PMID:2159541

  6. Formal verification of human-automation interaction.

    PubMed

    Degani, Asaf; Heymann, Michael

    2002-01-01

    This paper discusses a formal and rigorous approach to the analysis of operator interaction with machines. It addresses the acute problem of detecting design errors in human-machine interaction and focuses on verifying the correctness of the interaction in complex and automated control systems. The paper describes a systematic methodology for evaluating whether the interface provides the necessary information about the machine to enable the operator to perform a specified task successfully and unambiguously. It also addresses the adequacy of information provided to the user via training material (e.g., user manual) about the machine's behavior. The essentials of the methodology, which can be automated and applied to the verification of large systems, are illustrated by several examples and through a case study of pilot interaction with an autopilot aboard a modern commercial aircraft. The expected application of this methodology is an augmentation and enhancement, by formal verification, of human-automation interfaces.

  7. Formal verification of human-automation interaction

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Heymann, Michael

    2002-01-01

    This paper discusses a formal and rigorous approach to the analysis of operator interaction with machines. It addresses the acute problem of detecting design errors in human-machine interaction and focuses on verifying the correctness of the interaction in complex and automated control systems. The paper describes a systematic methodology for evaluating whether the interface provides the necessary information about the machine to enable the operator to perform a specified task successfully and unambiguously. It also addresses the adequacy of information provided to the user via training material (e.g., user manual) about the machine's behavior. The essentials of the methodology, which can be automated and applied to the verification of large systems, are illustrated by several examples and through a case study of pilot interaction with an autopilot aboard a modern commercial aircraft. The expected application of this methodology is an augmentation and enhancement, by formal verification, of human-automation interfaces.

  8. Effects of wheat germ agglutinin on human gastrointestinal epithelium: Insights from an experimental model of immune/epithelial cell interaction

    SciTech Connect

    Pellegrina, Chiara Dalla; Perbellini, Omar; Scupoli, Maria Teresa; Tomelleri, Carlo; Zanetti, Chiara; Zoccatelli, Gianni; Fusi, Marina; Peruffo, Angelo; Rizzi, Corrado; Chignola, Roberto

    2009-06-01

    Wheat germ agglutinin (WGA) is a plant protein that binds specifically to sugars expressed, among many others, by human gastrointestinal epithelial and immune cells. WGA is a toxic compound and an anti-nutritional factor, but recent works have shown that it may have potential as an anti-tumor drug and as a carrier for oral drugs. To quantitate the toxicity threshold for WGA on normal epithelial cells we previously investigated the effects of the lectin on differentiated Caco2 cells, and showed that in the micromolar range of concentrations WGA could alter the integrity of the epithelium layer and increase its permeability to both mannitol and dextran. WGA was shown to be uptaken by Caco2 cells and only {approx} 0.1% molecules were observed to cross the epithelium layer by transcytosis. Here we show that at nanomolar concentrations WGA is unexpectedly bioactive on immune cells. The supernatants of WGA-stimulated peripheral blood mononuclear cells (PBMC) can alter the integrity of the epithelium layer when administered to the basolateral side of differentiated Caco2 cells and the effects can be partially inhibited by monoclonal antibodies against IL1, IL6 and IL8. At nanomolar concentrations WGA stimulates the synthesis of pro-inflammatory cytokines and thus the biological activity of WGA should be reconsidered by taking into account the effects of WGA on the immune system at the gastrointestinal interface. These results shed new light onto the molecular mechanisms underlying the onset of gastrointestinal disorders observed in vivo upon dietary intake of wheat-based foods.

  9. The joy of interactive modeling

    NASA Astrophysics Data System (ADS)

    Donchyts, Gennadii; Baart, Fedor; van Dam, Arthur; Jagers, Bert

    2013-04-01

    The conventional way of working with hydrodynamical models usually consists of the following steps: 1) define a schematization (e.g., in a graphical user interface, or by editing input files) 2) run model from start to end 3) visualize results 4) repeat any of the previous steps. This cycle commonly takes up from hours to several days. What if we can make this happen instantly? As most of the research done using numerical models is in fact qualitative and exploratory (Oreskes et al., 1994), why not use these models as such? How can we adapt models so that we can edit model input, run and visualize results at the same time? More and more, interactive models become available as online apps, mainly for demonstration and educational purposes. These models often simplify the physics behind flows and run on simplified model geometries, particularly when compared with state-of-the-art scientific simulation packages. Here we show how the aforementioned conventional standalone models ("static, run once") can be transformed into interactive models. The basic concepts behind turning existing (conventional) model engines into interactive engines are the following. The engine does not run the model from start to end, but is always available in memory, and can be fed by new boundary conditions, or state changes at any time. The model can be run continuously, per step, or up to a specified time. The Hollywood principle dictates how the model engine is instructed from 'outside', instead of the model engine taking all necessary actions on its own initiative. The underlying techniques that facilitate these concepts are introspection of the computation engine, which exposes its state variables, and control functions, e.g. for time stepping, via a standardized interface, such as BMI (Peckam et. al., 2012). In this work we have used a shallow water flow model engine D-Flow Flexible Mesh. The model was converted from executable to a library, and coupled to the graphical modelling

  10. Fingertips detection for human computer interaction system

    NASA Astrophysics Data System (ADS)

    Alam, Md. Jahangir; Nasierding, Gulisong; Sajjanhar, Atul; Chowdhury, Morshed

    2014-01-01

    Fingertips of human hand play an important role in hand-based interaction with computers. Identification of fingertips' positions in hand images is vital for developing a human computer interaction system. This paper proposes a novel method for detecting fingertips of a hand image analyzing the concept of the geometrical structural information of fingers. The research is divided into three parts: First, hand image is segmented for detecting hand; Second, invariant features (curvature zero-crossing points) are extracted from the boundary of the hand; Third, fingertips are detected. Experimental results show that the proposed approach is promising.

  11. Interactions between human behaviour and ecological systems

    PubMed Central

    Milner-Gulland, E. J.

    2012-01-01

    Research on the interactions between human behaviour and ecological systems tends to focus on the direct effects of human activities on ecosystems, such as biodiversity loss. There is also increasing research effort directed towards ecosystem services. However, interventions to control people's use of the environment alter the incentives that natural resource users face, and therefore their decisions about resource use. The indirect effects of conservation interventions on biodiversity, modulated through human decision-making, are poorly studied but are likely to be significant and potentially counterintuitive. This is particularly so where people are dependent on multiple natural resources for their livelihoods, when both poverty and biodiversity loss are acute. An inter-disciplinary approach is required to quantify these interactions, with an understanding of human decision-making at its core; otherwise, predictions about the impacts of conservation policies may be highly misleading. PMID:22144389

  12. Human-Computer Interactions and Decision Behavior

    DTIC Science & Technology

    1984-01-01

    Narang A. Cohill J. Pittman J. Elkerton M. Revesman R. Fainter C. Rieger L. Folley J. Schurick M. Hakkinen A. Siochi D. Johnson T. Spine C. Ku M. Sti...W., Yunten, T., , Johnson , D. H. DMS: A comprehensive system for managing human- computer dialogue. In Proceedings of Human Factors in Computer...interactive system. Wel! known software metrics are used in this analysis. 3. The Dialogue Author a. Reports Johnson , D. H., Hartson, H. R. The role

  13. Interactive modeling of storm impact

    NASA Astrophysics Data System (ADS)

    van Rooijen, A.; Baart, F.; Roelvink, J. A.; Donchyts, G.; Scheel, F.; de Boer, W.

    2014-12-01

    In the past decades the impact of storms on the coastal zone has increasingly drawn the attention of policy makers and coastal planners, engineers and researchers. The mean reason for this interest is the high density of the world's population living near the ocean, in combination with climate change. Due to sea level rise and extremer weather conditions, many of the world's coastlines are becoming more vulnerable to the potential of flooding. Currently it is common practice to predict storm impact using physics-based numerical models. The numerical model utilizes several inputs (e.g. bathymetry, waves, surge) to calculate the impact on the coastline. Traditionally, the numerical modeller takes the following three steps: schematization/model setup, running and post-processing. This process generally has a total feedback time in the order of hours to days, and is suitable for so-called confirmatory modelling.However, often models are applied as an exploratory tool, in which the effect of e.g. different hydraulic conditions, or measures is investigated. The above described traditional work flow is not the most efficient method for exploratory modelling. Interactive modelling lets users adjust a simulation while running. For models typically used for storm impact studies (e.g. XBeach, Delft3D, D-Flow FM), the user can for instance change the storm surge level, wave conditions, or add a measure such as a nourishment or a seawall. The model will take the adjustments into account immediately, and will directly compute the effect. Using this method, tools can be developed in which stakeholders (e.g. coastal planners, policy makers) are in control and together evaluate ideas by interacting with the model. Here we will show initial results for interactive modelling with a storm impact model.

  14. Human Performance Modeling for Dynamic Human Reliability Analysis

    SciTech Connect

    Boring, Ronald Laurids; Joe, Jeffrey Clark; Mandelli, Diego

    2015-08-01

    Part of the U.S. Department of Energy’s (DOE’s) Light Water Reac- tor Sustainability (LWRS) Program, the Risk-Informed Safety Margin Charac- terization (RISMC) Pathway develops approaches to estimating and managing safety margins. RISMC simulations pair deterministic plant physics models with probabilistic risk models. As human interactions are an essential element of plant risk, it is necessary to integrate human actions into the RISMC risk framework. In this paper, we review simulation based and non simulation based human reliability analysis (HRA) methods. This paper summarizes the founda- tional information needed to develop a feasible approach to modeling human in- teractions in RISMC simulations.

  15. Can we develop a neurobiological model of human social-emotional development? Integrative thoughts on the effects of separation on parent-child interactions.

    PubMed

    Nelson, Charles A

    2003-12-01

    After summarizing the main points raised in articles by Kaslow et al. and Plotsk, a number of questions that derive from these authors' work are listed. Additional questions are then posed, the answers to which will likely facilitate one's ability to translate animal models of child psychopathology into human terms. After summarizing the various advantages and disadvantages to models using mice, rats, and monkeys, several examples of recent research that have attempted to meld animal models with human studies are described.

  16. Computer Human Interaction for Image Information Systems.

    ERIC Educational Resources Information Center

    Beard, David Volk

    1991-01-01

    Presents an approach to developing viable image computer-human interactions (CHI) involving user metaphors for comprehending image data and methods for locating, accessing, and displaying computer images. A medical-image radiology workstation application is used as an example, and feedback and evaluation methods are discussed. (41 references) (LRW)

  17. Computer Human Interaction for Image Information Systems.

    ERIC Educational Resources Information Center

    Beard, David Volk

    1991-01-01

    Presents an approach to developing viable image computer-human interactions (CHI) involving user metaphors for comprehending image data and methods for locating, accessing, and displaying computer images. A medical-image radiology workstation application is used as an example, and feedback and evaluation methods are discussed. (41 references) (LRW)

  18. Is Human-Computer Interaction Social or Parasocial?

    ERIC Educational Resources Information Center

    Sundar, S. Shyam

    Conducted in the attribution-research paradigm of social psychology, a study examined whether human-computer interaction is fundamentally social (as in human-human interaction) or parasocial (as in human-television interaction). All 30 subjects (drawn from an undergraduate class on communication) were exposed to an identical interaction with…

  19. Developing a Digital Human-Computer Interaction Laboratory

    DTIC Science & Technology

    2005-07-01

    Human - Computer Interaction Laboratory Lieutenant Colonel Terence S. Andre, USAF IITA Research...a Digital Human - Computer Interaction Laboratory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER...design, and human - computer interaction . He also oversees the human - computer interaction laboratory and directs cooperative agreements with

  20. Modeling Interactions in Small Groups

    ERIC Educational Resources Information Center

    Heise, David R.

    2013-01-01

    A new theory of interaction within small groups posits that group members initiate actions when tension mounts between the affective meanings of their situational identities and impressions produced by recent events. Actors choose partners and behaviors so as to reduce the tensions. A computer model based on this theory, incorporating reciprocal…

  1. Modeling Interactions in Small Groups

    ERIC Educational Resources Information Center

    Heise, David R.

    2013-01-01

    A new theory of interaction within small groups posits that group members initiate actions when tension mounts between the affective meanings of their situational identities and impressions produced by recent events. Actors choose partners and behaviors so as to reduce the tensions. A computer model based on this theory, incorporating reciprocal…

  2. Human interactions with sirenians (manatees and dugongs)

    USGS Publications Warehouse

    Bonde, Robert K.; Flint, Mark

    2017-01-01

    There are three extant sirenian species of the Trichechidae family and one living Dugongidae family member. Given their close ties to coastal and often urbanized habitats, sirenians are exposed to many types of anthropogenic activities that result in challenges to their well-being, poor health, and even death. In the wild, they are exposed to direct and indirect local pressures as well as subject to large-scale stressors such as global climate change acting on regions or entire genetic stocks. In captivity, they are subject to husbandry and management practices based on our collective knowledge, or in some cases lack thereof, of their needs and welfare. It is therefore reasonable to consider that their current imperiled status is very closely linked to our actions. In this chapter, we identify and define human interactions that may impact dugongs and manatees, including hunting, fisheries, boat interactions, negative interactions with man-made structures, disease and contaminants, and global climate change. We examine techniques used to investigate these impacts and the influence of sirenian biology and of changing human behaviors on potential outcomes. We examine how this differs for dugongs and manatees in the wild and for those held in captivity. Finally, we provide possible mitigation strategies and ways to assess the efforts we are making to improve the welfare of individuals and to conserve these species. This chapter identifies how the welfare of these species is intrinsically linked to the human interactions these animals experience, and how the nature of these interactions has changed with societal shifts. We proffer suggested ways to minimize negative impacts. Current knowledge should be used to minimize negative human interactions and impacts, to promote positive impacts, and to protect these animals for the future.

  3. Structural Characterization of the Binding Interactions of Various Endogenous Estrogen Metabolites with Human Estrogen Receptor α and β Subtypes: A Molecular Modeling Study

    PubMed Central

    Wang, Pan; McInnes, Campbell; Zhu, Bao Ting

    2013-01-01

    In the present study, we used the molecular docking approach to study the binding interactions of various derivatives of 17β-estradiol (E2) with human estrogen receptor (ER) α and β. First, we determined the suitability of the molecular docking method to correctly predict the binding modes and interactions of two representative agonists (E2 and diethylstilbesterol) in the ligand binding domain (LBD) of human ERα. We showed that the docked structures of E2 and diethylstilbesterol in the ERα LBD were almost exactly the same as the known crystal structures of ERα in complex with these two estrogens. Using the same docking approach, we then characterized the binding interactions of 27 structurally similar E2 derivatives with the LBDs of human ERα and ERβ. While the binding modes of these E2 derivatives are very similar to that of E2, there are distinct subtle differences, and these small differences contribute importantly to their differential binding affinities for ERs. In the case of A-ring estrogen derivatives, there is a strong inverse relationship between the length of the hydrogen bonds formed with ERs and their binding affinity. We found that a better correlation between the computed binding energy values and the experimentally determined logRBA values could be achieved for various A-ring derivatives by re-adjusting the relative weights of the van der Waals interaction energy and the Coulomb interaction energy in computing the overall binding energy values. PMID:24098659

  4. Multi-spectroscopic and molecular modeling studies of interaction between two different angiotensin I converting enzyme inhibitory peptides from gluten hydrolysate and human serum albumin.

    PubMed

    Assaran Darban, Reza; Shareghi, Behzad; Asoodeh, Ahmad; Chamani, Jamshidkhan

    2016-12-26

    The present study was carried out to characterize Angiotensin-converting enzyme (ACE) inhibitory peptides which are released from the trypsin hydrolysate of wheat gluten protein. The binding of two inhibitory peptide (P4 and P6) to human serum albumin (HSA) under physiological conditions has been investigated by multi-spectroscopic in combination with molecular modeling techniques. Time-resolved and quenching fluorescence spectroscopies results revealed that the quenching of HSA fluorescence by P4 and P6 in the binary and ternary systems caused HSA-peptides complexes formation. The results indicated that both peptides quenched the fluorescence intensity of HSA through a static mechanism. The binding affinities and number of binding sites were obtained for the HSA-peptides complexes. The circular dichroism (CD) data revealed that the presence of both peptides increased the α-helix content of HSA and induced the remarkable folding of the polypeptide of the protein. Therefore, the CD data determined that the protein structure has been stabilized in the percent of ACE inhibitory peptides in binary and ternary systems. The binding distances between HSA and both peptides were estimated by the Forster theory, and it was revealed that nonradiative energy transfer from HSA to peptides occurred with a high probability. ITC experiments reveal that, in the absence and presence of P6, the dominant forces are electrostatic in binary and ternary systems. Furthermore, molecular modeling studies confirmed the experimental results. Molecular modeling investigation suggested that P4 bound to the site IA and IIA of HSA in binary and ternary systems, respectively. This study on the interaction of peptides with HSA should prove helpful for realizing the distribution and transportation of food compliments and drugs in vivo, elucidating the action mechanism and dynamics of food compliments and drugs at the molecular level. It should moreover be of great use for understanding the

  5. Automatic mapping and modeling of human networks

    NASA Astrophysics Data System (ADS)

    Pentland, Alex (Sandy)

    2007-05-01

    Mobile telephones, company ID badges, and similar common devices form a sensor network which can be used to map human activity, and especially human interactions. The most informative sensor data seem to be measurements of person-to-person proximity, and statistics of vocalization and body movement measurements. Using this data to model individual behavior as a stochastic process allows prediction of future activity, with the greatest predictive power obtained by modeling the interactions between individual processes. Experiments show that between 40% and 95% of the variance in human behavior may be explained by such models.

  6. Policy Interactions in Human-Landscape Systems

    NASA Astrophysics Data System (ADS)

    Gerlak, Andrea K.

    2014-01-01

    Given the heightened pace and extent of human interactions with landscapes, there is increasing recognition of the interdependence of hydrogeomorphological, ecological, and human systems in understanding human-landscape interactions. There is also widespread agreement for greater integration across disciplinary boundaries to generate new knowledge urgently needed for theory building to understand, predict, and respond to rapidly changing human-landscape systems. The development of new conceptual frameworks, methods, tools, and collaborations linking across the natural and social sciences are key elements to such integration. In an effort to contribute to a broader conceptual framework for human-landscape systems, this paper describes how environmental policy research has contributed to four integrative themes—thresholds and tipping points; spatial scales and boundaries; feedback loops; and time scales and lags—developed by participants in an NSF-sponsored interdisciplinary workshop. As a broad and heterogeneous body of literature, environmental policy research reflects a diversity of methodological and theoretical approaches around institutions, actors, processes, and ideas. We integrate across multiple subfields and research programs to help identify complementarities in research that may support future interdisciplinary collaborative work. We conclude with a discussion of future research questions to help advance greater interdisciplinary research around human-landscape systems.

  7. Models of dyadic social interaction.

    PubMed Central

    Griffin, Dale; Gonzalez, Richard

    2003-01-01

    We discuss the logic of research designs for dyadic interaction and present statistical models with parameters that are tied to psychologically relevant constructs. Building on Karl Pearson's classic nineteenth-century statistical analysis of within-organism similarity, we describe several approaches to indexing dyadic interdependence and provide graphical methods for visualizing dyadic data. We also describe several statistical and conceptual solutions to the 'levels of analytic' problem in analysing dyadic data. These analytic strategies allow the researcher to examine and measure psychological questions of interdependence and social influence. We provide illustrative data from casually interacting and romantic dyads. PMID:12689382

  8. Studies on the interaction between promethazine and human serum albumin in the presence of flavonoids by spectroscopic and molecular modeling techniques.

    PubMed

    He, Ling-Ling; Wang, Zhi-Xin; Wang, Yong-Xia; Liu, Xian-Ping; Yang, Yan-Jie; Gao, Yan-Ping; Wang, Xin; Liu, Bin; Wang, Xin

    2016-09-01

    Fluorescence, absorption, time-correlated single photon counting (TCSPC), and circular dichroism (CD) spectroscopic techniques as well as molecular modeling methods were used to study the binding characterization of promethazine (PMT) to human serum albumin (HSA) and the influence of flavonoids, rutin and baicalin, on their affinity. The results indicated that the fluorescence quenching mechanism of HSA by PMT is a static quenching due to the formation of complex. The reaction was spontaneous and mainly mediated by hydrogen bonds and hydrophobic interactions. The binding distance between the tryptophan residue of HSA and PMT is less than 8nm, which indicated that the energy transfer from the tryptophan residue of HSA to PMT occurred. The binding site of PMT on HSA was located in sites I and the presence of PMT can cause the conformational changes of HSA. There was the competitive binding to HSA between PMT and flavonoids because of the overlap of binding sites in HSA. The flavonoids could decrease the association constant and increase the binding distance. In addition, their synergistic effect can further change the conformation of HSA. The decrease in the affinities of PMT binding to HSA in the presence of flavonoids may lead to the increase of free drug in blood, which would affect the transportation or disposition of drug and evoke an adverse or toxic effect. Hence, rationalising dosage and diet regimens should be taken into account in clinical application of PMT.

  9. Holoprosencephaly: signalling interactions between the brain and the face, the environment and the genes, and the phenotypic variability in animal models and humans

    PubMed Central

    Graf, Daniel; Marcucio, Ralph

    2014-01-01

    Holoprosencephaly (HPE) is the most common developmental defect of the forebrain characterized by inadequate or absent midline division of the forebrain into cerebral hemispheres, with concomitant midline facial defects in the majority of cases. Understanding the pathogenesis of HPE requires knowledge of the relationship between the developing brain and the facial structures during embryogenesis. A number of signalling pathways control and coordinate the development of the brain and face, including Sonic hedgehog (SHH), Bone Morphogenetic Protein (BMP), Fibroblast Growth Factor (FGF), and Nodal signalling. Mutations in these pathways have been identified in animal models of HPE and human patients. Due to incomplete penetrance and variable expressivity of HPE, patients carrying defined mutations may not manifest the disease at all, or have a spectrum of defects. It is currently unknown what drives manifestation of HPE in genetically at risk individuals, but it has been speculated that other gene mutations and environmental factors may combine as cumulative insults. HPE can be diagnosed in utero by a high-resolution prenatal ultrasound or a fetal magnetic resonance imaging, sometimes in combination with molecular testing from chorionic villi or amniotic fluid sampling. Currently, there are no effective preventive methods for HPE. Better understanding of the mechanisms of gene-environment interactions in HPE would provide avenues for such interventions. PMID:25339593

  10. Holoprosencephaly: signaling interactions between the brain and the face, the environment and the genes, and the phenotypic variability in animal models and humans.

    PubMed

    Petryk, Anna; Graf, Daniel; Marcucio, Ralph

    2015-01-01

    Holoprosencephaly (HPE) is the most common developmental defect of the forebrain characterized by inadequate or absent midline division of the forebrain into cerebral hemispheres, with concomitant midline facial defects in the majority of cases. Understanding the pathogenesis of HPE requires knowledge of the relationship between the developing brain and the facial structures during embryogenesis. A number of signaling pathways control and coordinate the development of the brain and face, including Sonic hedgehog, Bone morphogenetic protein, Fibroblast growth factor, and Nodal signaling. Mutations in these pathways have been identified in animal models of HPE and human patients. Because of incomplete penetrance and variable expressivity of HPE, patients carrying defined mutations may not manifest the disease at all, or have a spectrum of defects. It is currently unknown what drives manifestation of HPE in genetically at-risk individuals, but it has been speculated that other gene mutations and environmental factors may combine as cumulative insults. HPE can be diagnosed in utero by a high-resolution prenatal ultrasound or a fetal magnetic resonance imaging, sometimes in combination with molecular testing from chorionic villi or amniotic fluid sampling. Currently, there are no effective preventive methods for HPE. Better understanding of the mechanisms of gene-environment interactions in HPE would provide avenues for such interventions.

  11. A model for triple helix formation on human telomerase reverse transcriptase (hTERT) promoter and stabilization by specific interactions with the water soluble perylene derivative, DAPER.

    PubMed

    Rossetti, Luigi; D'Isa, Giuliana; Mauriello, Clementina; Varra, Michela; De Santis, Pasquale; Mayol, Luciano; Savino, Maria

    2007-08-01

    The promoter of human telomerase reverse transcriptase (hTERT) gene, in the region from -1000 to +1, contains two homopurine-homopyrimidine sequences (-835/-814 and -108/-90), that can be considered as potential targets to triple helix forming oligonucleotides (TFOs) for applying antigene strategy. We have chosen the sequence (-108/-90) on the basis of its unfavorable chromatin organization, evaluated by theoretical nucleosome positioning and nuclease hypersensitive sites mapping. On this sequence, anti-parallel triplex with satisfactory thermodynamic stability is formed by two TFOs, having different lengths. Triplex stability is significantly increased by specific interactions with the perylene derivative N,N'-bis[3,3'-(dimethylamino) propylamine]-3,4,9,10-perylenetetracarboxylic diimide (DAPER). Since DAPER is a symmetric molecule, the induced Circular Dichroism (CD) spectra in the range 400-600 nm allows us to obtain information on drug binding to triplex and duplex DNA. The drug-induced ellipticity is significantly higher in the case of triplex with respect to duplex and, surprisingly, it increases at decreasing of DNA. A model is proposed where self-stacked DAPER binds to triplex or to duplex narrow grooves.

  12. The human dynamic clamp as a paradigm for social interaction

    PubMed Central

    Dumas, Guillaume; de Guzman, Gonzalo C.; Tognoli, Emmanuelle; Kelso, J. A. Scott

    2014-01-01

    Social neuroscience has called for new experimental paradigms aimed toward real-time interactions. A distinctive feature of interactions is mutual information exchange: One member of a pair changes in response to the other while simultaneously producing actions that alter the other. Combining mathematical and neurophysiological methods, we introduce a paradigm called the human dynamic clamp (HDC), to directly manipulate the interaction or coupling between a human and a surrogate constructed to behave like a human. Inspired by the dynamic clamp used so productively in cellular neuroscience, the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject’s own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual “teacher.” We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof. PMID:25114256

  13. Multiple scales modelling approaches to social interaction in crowd dynamics and crisis management. Comment on "Human behaviours in evacuation crowd dynamics: From modelling to "big data" toward crisis management" by Nicola Bellomo et al.

    NASA Astrophysics Data System (ADS)

    Trucu, Dumitru

    2016-09-01

    In this comprehensive review concerning the modelling of human behaviours in crowd dynamics [3], the authors explore a wide range of mathematical approaches spanning over multiple scales that are suitable to describe emerging crowd behaviours in extreme situations. Focused on deciphering the key aspects leading to emerging crowd patterns evolutions in challenging times such as those requiring an evacuation on a complex venue, the authors address this complex dynamics at both microscale (individual level), mesoscale (probability distributions of interacting individuals), and macroscale (population level), ultimately aiming to gain valuable understanding and knowledge that would inform decision making in managing crisis situations.

  14. Comparing the interaction of cyclophosphamide monohydrate to human serum albumin as opposed to holo-transferrin by spectroscopic and molecular modeling methods: evidence for allocating the binding site.

    PubMed

    Tousi, Shirin Hamed-Akbari; Saberi, Mohammad Reza; Chamani, Jamshidkhan

    2010-12-01

    The interaction between cyclophosphamide monohydrate with human serum albumin (HSA) and human serum transferrin (hTf) was studied with UV absorption, fluorescence and circular dichroism (CD) spectroscopies as well as molecular modeling. Based on the fluorescence quenching results, it was determined that HSA and hTf had two classes of apparent binding constants and binding sites at physiological conditions. The K(SV1), K(SV2), n(1) and n(2) values for HSA were found to be 8.6 x 10(8) Lmol(-1), 6.34 x 10(8) Lmol(-1), 0.7 and 0.8, respectively, and the corresponding results for hTf were 6.08 x 10(7) Lmol(-1), 4.65 x 10(7) Lmol(-1), 1.3 and 2.6, respectively. However, the binding affinity of cyclophosphamide monohydrate to HSA was more significant than to hTf. Circular dichroism results demonstrated that the binding of cyclophosphamide to HSA and hTf induced secondary changes in the structure and that the a-helix content became altered into b-sheet, turn and random coil forms. The participation of tyrosyl and tryptophan residues of proteins was also estimated in the drug-HSA and hTf complexes by synchronous fluorescence. The micro-environment of the HSA and hTf fluorophores was transferred to hydrophobic and hydrophilic conditions, respectively. The distance r between donor and acceptor was obtained by the Forster energy according to fluorescence resonance energy transfer (FRET) and found to be 1.84 nm and 1.73 nm for HSA and hTf, respectively. This confirmed the existence of static quenching for both proteins in the presence of cyclophosphamide monohydrate. Site marker competitive displacement experiments demonstrated that cyclophosphamide bound with high affinity to Site II, sub-domain IIIA of HSA, and for hTf, the C-lobe constituted the binding site. Furthermore, a study of molecular modeling showed that cyclophosphamide situated in domain II in HSA was bound through hydrogen bonding with Arg 257 and Ser 287, and that cyclophosphamide was situated in the C-lobe in h

  15. User localization during human-robot interaction.

    PubMed

    Alonso-Martín, F; Gorostiza, Javi F; Malfaz, María; Salichs, Miguel A

    2012-01-01

    This paper presents a user localization system based on the fusion of visual information and sound source localization, implemented on a social robot called Maggie. One of the main requisites to obtain a natural interaction between human-human and human-robot is an adequate spatial situation between the interlocutors, that is, to be orientated and situated at the right distance during the conversation in order to have a satisfactory communicative process. Our social robot uses a complete multimodal dialog system which manages the user-robot interaction during the communicative process. One of its main components is the presented user localization system. To determine the most suitable allocation of the robot in relation to the user, a proxemic study of the human-robot interaction is required, which is described in this paper. The study has been made with two groups of users: children, aged between 8 and 17, and adults. Finally, at the end of the paper, experimental results with the proposed multimodal dialog system are presented.

  16. User Localization During Human-Robot Interaction

    PubMed Central

    Alonso-Martín, F.; Gorostiza, Javi F.; Malfaz, María; Salichs, Miguel A.

    2012-01-01

    This paper presents a user localization system based on the fusion of visual information and sound source localization, implemented on a social robot called Maggie. One of the main requisites to obtain a natural interaction between human-human and human-robot is an adequate spatial situation between the interlocutors, that is, to be orientated and situated at the right distance during the conversation in order to have a satisfactory communicative process. Our social robot uses a complete multimodal dialog system which manages the user-robot interaction during the communicative process. One of its main components is the presented user localization system. To determine the most suitable allocation of the robot in relation to the user, a proxemic study of the human-robot interaction is required, which is described in this paper. The study has been made with two groups of users: children, aged between 8 and 17, and adults. Finally, at the end of the paper, experimental results with the proposed multimodal dialog system are presented. PMID:23012577

  17. Human-Robot Interaction Directed Research Project

    NASA Technical Reports Server (NTRS)

    Rochlis, Jennifer; Ezer, Neta; Sandor, Aniko

    2011-01-01

    Human-robot interaction (HRI) is about understanding and shaping the interactions between humans and robots (Goodrich & Schultz, 2007). It is important to evaluate how the design of interfaces and command modalities affect the human s ability to perform tasks accurately, efficiently, and effectively (Crandall, Goodrich, Olsen Jr., & Nielsen, 2005) It is also critical to evaluate the effects of human-robot interfaces and command modalities on operator mental workload (Sheridan, 1992) and situation awareness (Endsley, Bolt , & Jones, 2003). By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed that support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for design. Because the factors associated with interfaces and command modalities in HRI are too numerous to address in 3 years of research, the proposed research concentrates on three manageable areas applicable to National Aeronautics and Space Administration (NASA) robot systems. These topic areas emerged from the Fiscal Year (FY) 2011 work that included extensive literature reviews and observations of NASA systems. The three topic areas are: 1) video overlays, 2) camera views, and 3) command modalities. Each area is described in detail below, along with relevance to existing NASA human-robot systems. In addition to studies in these three topic areas, a workshop is proposed for FY12. The workshop will bring together experts in human-robot interaction and robotics to discuss the state of the practice as applicable to research in space robotics. Studies proposed in the area of video overlays consider two factors in the implementation of augmented reality (AR) for operator displays during teleoperation. The first of these factors is the type of navigational guidance provided by AR symbology. In the proposed

  18. A computer-human interaction model to improve the diagnostic accuracy and clinical decision-making during 12-lead electrocardiogram interpretation.

    PubMed

    Cairns, Andrew W; Bond, Raymond R; Finlay, Dewar D; Breen, Cathal; Guldenring, Daniel; Gaffney, Robert; Gallagher, Anthony G; Peace, Aaron J; Henn, Pat

    2016-12-01

    The 12-lead Electrocardiogram (ECG) presents a plethora of information and demands extensive knowledge and a high cognitive workload to interpret. Whilst the ECG is an important clinical tool, it is frequently incorrectly interpreted. Even expert clinicians are known to impulsively provide a diagnosis based on their first impression and often miss co-abnormalities. Given it is widely reported that there is a lack of competency in ECG interpretation, it is imperative to optimise the interpretation process. Predominantly the ECG interpretation process remains a paper based approach and whilst computer algorithms are used to assist interpreters by providing printed computerised diagnoses, there are a lack of interactive human-computer interfaces to guide and assist the interpreter. An interactive computing system was developed to guide the decision making process of a clinician when interpreting the ECG. The system decomposes the interpretation process into a series of interactive sub-tasks and encourages the clinician to systematically interpret the ECG. We have named this model 'Interactive Progressive based Interpretation' (IPI) as the user cannot 'progress' unless they complete each sub-task. Using this model, the ECG is segmented into five parts and presented over five user interfaces (1: Rhythm interpretation, 2: Interpretation of the P-wave morphology, 3: Limb lead interpretation, 4: QRS morphology interpretation with chest lead and rhythm strip presentation and 5: Final review of 12-lead ECG). The IPI model was implemented using emerging web technologies (i.e. HTML5, CSS3, AJAX, PHP and MySQL). It was hypothesised that this system would reduce the number of interpretation errors and increase diagnostic accuracy in ECG interpreters. To test this, we compared the diagnostic accuracy of clinicians when they used the standard approach (control cohort) with clinicians who interpreted the same ECGs using the IPI approach (IPI cohort). For the control cohort, the

  19. Anisotropic exchange-interaction model: From the Potts model to the exchange-interaction model

    NASA Astrophysics Data System (ADS)

    King, T. C.; Chen, H. H.

    1995-04-01

    A spin model called the anisotropic exchange-interaction model is proposed. The Potts model, the exchange-interaction model, and the spin-1/2 anisotropic Heisenberg model are special cases of the proposed model. Thermodynamic properties of the model on the bcc and the fcc lattices are determined by the constant-coupling approximation.

  20. Human computer interaction issues in Clinical Trials Management Systems.

    PubMed

    Starren, Justin B; Payne, Philip R O; Kaufman, David R

    2006-01-01

    Clinical trials increasingly rely upon web-based Clinical Trials Management Systems (CTMS). As with clinical care systems, Human Computer Interaction (HCI) issues can greatly affect the usefulness of such systems. Evaluation of the user interface of one web-based CTMS revealed a number of potential human-computer interaction problems, in particular, increased workflow complexity associated with a web application delivery model and potential usability problems resulting from the use of ambiguous icons. Because these design features are shared by a large fraction of current CTMS, the implications extend beyond this individual system.

  1. Human Computer Interaction Issues in Clinical Trials Management Systems

    PubMed Central

    Starren, Justin B.; Payne, Philip R.O.; Kaufman, David R.

    2006-01-01

    Clinical trials increasingly rely upon web-based Clinical Trials Management Systems (CTMS). As with clinical care systems, Human Computer Interaction (HCI) issues can greatly affect the usefulness of such systems. Evaluation of the user interface of one web-based CTMS revealed a number of potential human-computer interaction problems, in particular, increased workflow complexity associated with a web application delivery model and potential usability problems resulting from the use of ambiguous icons. Because these design features are shared by a large fraction of current CTMS, the implications extend beyond this individual system. PMID:17238728

  2. A human protein interaction network shows conservation of aging processes between human and invertebrate species.

    PubMed

    Bell, Russell; Hubbard, Alan; Chettier, Rakesh; Chen, Di; Miller, John P; Kapahi, Pankaj; Tarnopolsky, Mark; Sahasrabuhde, Sudhir; Melov, Simon; Hughes, Robert E

    2009-03-01

    We have mapped a protein interaction network of human homologs of proteins that modify longevity in invertebrate species. This network is derived from a proteome-scale human protein interaction Core Network generated through unbiased high-throughput yeast two-hybrid searches. The longevity network is composed of 175 human homologs of proteins known to confer increased longevity through loss of function in yeast, nematode, or fly, and 2,163 additional human proteins that interact with these homologs. Overall, the network consists of 3,271 binary interactions among 2,338 unique proteins. A comparison of the average node degree of the human longevity homologs with random sets of proteins in the Core Network indicates that human homologs of longevity proteins are highly connected hubs with a mean node degree of 18.8 partners. Shortest path length analysis shows that proteins in this network are significantly more connected than would be expected by chance. To examine the relationship of this network to human aging phenotypes, we compared the genes encoding longevity network proteins to genes known to be changed transcriptionally during aging in human muscle. In the case of both the longevity protein homologs and their interactors, we observed enrichments for differentially expressed genes in the network. To determine whether homologs of human longevity interacting proteins can modulate life span in invertebrates, homologs of 18 human FRAP1 interacting proteins showing significant changes in human aging muscle were tested for effects on nematode life span using RNAi. Of 18 genes tested, 33% extended life span when knocked-down in Caenorhabditis elegans. These observations indicate that a broad class of longevity genes identified in invertebrate models of aging have relevance to human aging. They also indicate that the longevity protein interaction network presented here is enriched for novel conserved longevity proteins.

  3. Interaction of Human Hemoglobin with Methotrexate

    NASA Astrophysics Data System (ADS)

    Zaharia, M.; Gradinaru, R.

    2015-05-01

    This study focuses on the interaction between methotrexate and human hemoglobin using steady-state ultraviolet-visible and fluorescence quenching methods. Fluorescence quenching was found to be valuable in assessing drug binding to hemoglobin. The quenching of methotrexate is slightly smaller than the quenching observed with related analogs (dihydrofolate and tetrahydrofolate). The quenching studies were performed at four different temperatures and various pH values. The number of binding sites for tryptophan is ~1. Parameter-dependent assays revealed that electrostatic forces play an essential role in the methotrexate-hemoglobin interaction. Furthermore, the complex was easily eluted using gel filtration chromatography.

  4. Stochastic hyperfine interactions modeling library

    NASA Astrophysics Data System (ADS)

    Zacate, Matthew O.; Evenson, William E.

    2011-04-01

    The stochastic hyperfine interactions modeling library (SHIML) provides a set of routines to assist in the development and application of stochastic models of hyperfine interactions. The library provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental techniques that measure hyperfine interactions can be calculated. The optimized vector and matrix operations of the BLAS and LAPACK libraries are utilized; however, there was a need to develop supplementary code to find an orthonormal set of (left and right) eigenvectors of complex, non-Hermitian matrices. In addition, example code is provided to illustrate the use of SHIML to generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A can be neglected. Program summaryProgram title: SHIML Catalogue identifier: AEIF_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPL 3 No. of lines in distributed program, including test data, etc.: 8224 No. of bytes in distributed program, including test data, etc.: 312 348 Distribution format: tar.gz Programming language: C Computer: Any Operating system: LINUX, OS X RAM: Varies Classification: 7.4 External routines: TAPP [1], BLAS [2], a C-interface to BLAS [3], and LAPACK [4] Nature of problem: In condensed matter systems, hyperfine methods such as nuclear magnetic resonance (NMR), Mössbauer effect (ME), muon spin rotation (μSR), and perturbed angular correlation spectroscopy (PAC) measure electronic and magnetic structure within Angstroms of nuclear probes through the hyperfine interaction. When

  5. BaffleText: a Human Interactive Proof

    NASA Astrophysics Data System (ADS)

    Chew, Monica; Baird, Henry S.

    2003-01-01

    Internet services designed for human use are being abused by programs. We present a defense against such attacks in the form of a CAPTCHA (Completely Automatic Public Turing test to tell Computers and Humans Apart) that exploits the difference in ability between humans and machines in reading images of text. CAPTCHAs are a special case of 'human interactive proofs,' a broad class of security protocols that allow people to identify themselves over networks as members of given groups. We point out vulnerabilities of reading-based CAPTCHAs to dictionary and computer-vision attacks. We also draw on the literature on the psychophysics of human reading, which suggests fresh defenses available to CAPTCHAs. Motivated by these considerations, we propose BaffleText, a CAPTCHA which uses non-English pronounceable words to defend against dictionary attacks, and Gestalt-motivated image-masking degradations to defend against image restoration attacks. Experiments on human subjects confirm the human legibility and user acceptance of BaffleText images. We have found an image-complexity measure that correlates well with user acceptance and assists in engineering the generation of challenges to fit the ability gap. Recent computer-vision attacks, run independently by Mori and Jitendra, suggest that BaffleText is stronger than two existing CAPTCHAs.

  6. Endocrine immune interactions in human parturition.

    PubMed

    Golightly, E; Jabbour, H N; Norman, J E

    2011-03-15

    Human parturition is an inflammatory event, modulated and influenced by a host of other environmental and physiological processes, including the endocrine hormones. Complex bidirectional communication occurs between the two systems to bring about some of the changes that are seen in labour, an event that is not yet fully understood. Preterm birth is a major problem in obstetrics and neonatology, with dysfunctional labour or prolonged pregnancy also making increasingly significant contributions to maternal morbidity. With better understanding of normal and abnormal parturition we may be able to develop novel ways of treating these complications of pregnancy and reduce maternal and neonatal morbidity and mortality. This review discusses the crucial role that endocrine-immune interaction plays in the process of labour and in the processes of abnormal and preterm labour. We propose that amongst these complex interactions it is the immune system that is the driving force behind human parturition. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Common Metrics for Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Steinfeld, Aaron; Lewis, Michael; Fong, Terrence; Scholtz, Jean; Schultz, Alan; Kaber, David; Goodrich, Michael

    2006-01-01

    This paper describes an effort to identify common metrics for task-oriented human-robot interaction (HRI). We begin by discussing the need for a toolkit of HRI metrics. We then describe the framework of our work and identify important biasing factors that must be taken into consideration. Finally, we present suggested common metrics for standardization and a case study. Preparation of a larger, more detailed toolkit is in progress.

  8. Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

    PubMed

    Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

    2015-02-01

    During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

  9. Computers in the Human Interaction Loop

    NASA Astrophysics Data System (ADS)

    Waibel, A.; Stiefelhagen, R.; Carlson, R.; Casas, J.; Kleindienst, J.; Lamel, L.; Lanz, O.; Mostefa, D.; Omologo, M.; Pianesi, F.; Polymenakos, L.; Potamianos, G.; Soldatos, J.; Sutschet, G.; Terken, J.

    It is a common experience in our modern world, for us humans to be overwhelmed by the complexities of technological artifacts around us, and by the attention they demand. While technology provides wonderful support and helpful assistance, it also causes an increased preoccupation with technology itself and a related fragmentation of attention. But as humans, we would rather attend to a meaningful dialog and interaction with other humans, than to control the operations of machines that serve us. The cause for such complexity and distraction, however, is a natural consequence of the flexibility and choice of functions and features that technology has to offer. Thus flexibility of choice and the availability of desirable functions are in conflict with ease of use and our very ability to enjoy their benefits.

  10. Human systems dynamics: Toward a computational model

    NASA Astrophysics Data System (ADS)

    Eoyang, Glenda H.

    2012-09-01

    A robust and reliable computational model of complex human systems dynamics could support advancements in theory and practice for social systems at all levels, from intrapersonal experience to global politics and economics. Models of human interactions have evolved from traditional, Newtonian systems assumptions, which served a variety of practical and theoretical needs of the past. Another class of models has been inspired and informed by models and methods from nonlinear dynamics, chaos, and complexity science. None of the existing models, however, is able to represent the open, high dimension, and nonlinear self-organizing dynamics of social systems. An effective model will represent interactions at multiple levels to generate emergent patterns of social and political life of individuals and groups. Existing models and modeling methods are considered and assessed against characteristic pattern-forming processes in observed and experienced phenomena of human systems. A conceptual model, CDE Model, based on the conditions for self-organizing in human systems, is explored as an alternative to existing models and methods. While the new model overcomes the limitations of previous models, it also provides an explanatory base and foundation for prospective analysis to inform real-time meaning making and action taking in response to complex conditions in the real world. An invitation is extended to readers to engage in developing a computational model that incorporates the assumptions, meta-variables, and relationships of this open, high dimension, and nonlinear conceptual model of the complex dynamics of human systems.

  11. The role of gut microbiota in health and disease: In vitro modeling of host-microbe interactions at the aerobe-anaerobe interphase of the human gut.

    PubMed

    von Martels, Julius Z H; Sadaghian Sadabad, Mehdi; Bourgonje, Arno R; Blokzijl, Tjasso; Dijkstra, Gerard; Faber, Klaas Nico; Harmsen, Hermie J M

    2017-04-01

    The microbiota of the gut has many crucial functions in human health. Dysbiosis of the microbiota has been correlated to a large and still increasing number of diseases. Recent studies have mostly focused on analyzing the associations between disease and an aberrant microbiota composition. Functional studies using (in vitro) gut models are required to investigate the precise interactions that occur between specific bacteria (or bacterial mixtures) and gut epithelial cells. As most gut bacteria are obligate or facultative anaerobes, studying their effect on oxygen-requiring human gut epithelial cells is technically challenging. Still, several (anaerobic) bacterial-epithelial co-culture systems have recently been developed that mimic host-microbe interactions occurring in the human gut, including 1) the Transwell "apical anaerobic model of the intestinal epithelial barrier", 2) the Host-Microbiota Interaction (HMI) module, 3) the "Human oxygen-Bacteria anaerobic" (HoxBan) system, 4) the human gut-on-a-chip and 5) the HuMiX model. This review discusses the role of gut microbiota in health and disease and gives an overview of the characteristics and applications of these novel host-microbe co-culture systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Modeling Human-Computer Decision Making with Covariance Structure Analysis.

    ERIC Educational Resources Information Center

    Coovert, Michael D.; And Others

    Arguing that sufficient theory exists about the interplay between human information processing, computer systems, and the demands of various tasks to construct useful theories of human-computer interaction, this study presents a structural model of human-computer interaction and reports the results of various statistical analyses of this model.…

  13. Interacting Boson Model and nucleons

    NASA Astrophysics Data System (ADS)

    Otsuka, Takaharu

    2012-10-01

    An overview on the recent development of the microscopic derivation of the Interacting Boson Model is presented with some remarks not found elsewhere. The OAI mapping is reviewed very briefly, including the basic correspondence from nucleon-pair to boson. The new fermionboson mapping method is introduced, where intrinsic states of nucleons and bosons for a wide variation of shapes play an important role. Nucleon intrinsic states are obtained from mean field models, which is Skyrme model in examples to be shown. This method generates IBM-2 Hamiltonian which can describe and predict various situations of quadrupole collective states, including U(5), SU(3), O(6) and E(5) limits. The method is extended so that rotational response (cranking) can be handled, which enables us to describe rotational bands of strongly deformed nuclei. Thus, we have obtained a unified framework for the microscopic derivation of the IBM covering all known situations of quadrupole collectivity at low energy.

  14. From human-machine interaction to human-machine cooperation.

    PubMed

    Hoc, J M

    2000-07-01

    Since the 1960s, the rapid growth of information systems has led to the wide development of research on human-computer interaction (HCI) that aims at the designing of human-computer interfaces presenting ergonomic properties, such as friendliness, usability, transparency, etc. Various work situations have been covered--clerical work, computer programming, design, etc. However, they were mainly static in the sense that the user fully controls the computer. More recently, public and private organizations have engaged themselves in the enterprise of managing more and more complex and coupled systems by the means of automation. Modern machines not only process information, but also act on dynamic situations as humans have done in the past, managing stock exchange, industrial plants, aircraft, etc. These dynamic situations are not fully controlled and are affected by uncertain factors. Hence, degrees of freedom must be maintained to allow the humans and the machine to adapt to unforeseen contingencies. A human-machine cooperation (HMC) approach is necessary to address the new stakes introduced by this trend. This paper describes the possible improvement of HCI by HMC, the need for a new conception of function allocation between humans and machines, and the main problems encountered within the new forms of human-machine relationship. It proposes a conceptual framework to study HMC from a cognitive point of view in highly dynamic situations like aircraft piloting or air-traffic control, and concludes on the design of 'cooperative' machines.

  15. Human jaw and muscle modelling.

    PubMed

    Peck, Christopher C; Hannam, Alan G

    2007-04-01

    Dynamic mathematical modelling is an invaluable method to help understand the biomechanics of the anatomically and functionally complex masticatory system. It provides insight into variables which are impossible to measure directly such as joint loads and individual muscle tensions, and into physical relationships between jaw structure and function. Individual parameters can be modified easily to understand their influence on function. Our models are constructed with best available structural and functional data, and evaluated against human jaw behaviour. Image data provide hard and soft tissue morphology and the jaw's inertial properties. The drive to the system is provided by actuators which simulate active and passive jaw muscle properties. In whole-jaw modelling, muscle models which behave plausibly rather than mimic the ultra-structural cross-bridge interactions are common since they are computationally feasible. Whole-jaw models have recently incorporated flexible finite-elements to explore tissue distortion in the temporomandibular joint and tongue movements. Furthermore, the jaw has been integrated with laryngeal models to explore complex tasks such as swallowing. These dynamic models have helped better understand joint loading, movement constraints and muscle activation strategies. Future directions will include further incorporation of rigid and flexible model dynamics and the creation of subject-specific models to better understand the functional implications of pathology.

  16. Metaphors for the Nature of Human-Computer Interaction in an Empowering Environment: Interaction Style Influences the Manner of Human Accomplishment.

    ERIC Educational Resources Information Center

    Weller, Herman G.; Hartson, H. Rex

    1992-01-01

    Describes human-computer interface needs for empowering environments in computer usage in which the machine handles the routine mechanics of problem solving while the user concentrates on its higher order meanings. A closed-loop model of interaction is described, interface as illusion is discussed, and metaphors for human-computer interaction are…

  17. Interaction of Staphylococci with Human B cells

    PubMed Central

    Nygaard, Tyler K.; Kobayashi, Scott D.; Freedman, Brett; Porter, Adeline R.; Voyich, Jovanka M.; Otto, Michael; Schneewind, Olaf; DeLeo, Frank R.

    2016-01-01

    Staphylococcus aureus is a leading cause of human infections worldwide. The pathogen produces numerous molecules that can interfere with recognition and binding by host innate immune cells, an initial step required for the ingestion and subsequent destruction of microbes by phagocytes. To better understand the interaction of this pathogen with human immune cells, we compared the association of S. aureus and S. epidermidis with leukocytes in human blood. We found that a significantly greater proportion of B cells associated with S. epidermidis relative to S. aureus. Complement components and complement receptors were important for the binding of B cells with S. epidermidis. Experiments using staphylococci inactivated by ultraviolet radiation and S. aureus isogenic deletion mutants indicated that S. aureus secretes molecules regulated by the SaeR/S two-component system that interfere with the ability of human B cells to bind this bacterium. We hypothesize that the relative inability of B cells to bind S. aureus contributes to the microbe’s success as a human pathogen. PMID:27711145

  18. Ferromagnetic interaction model of activity level in workplace communication

    NASA Astrophysics Data System (ADS)

    Akitomi, Tomoaki; Ara, Koji; Watanabe, Jun-ichiro; Yano, Kazuo

    2013-03-01

    The nature of human-human interaction, specifically, how people synchronize with each other in multiple-participant conversations, is described by a ferromagnetic interaction model of people’s activity levels. We found two microscopic human interaction characteristics from a real-environment face-to-face conversation. The first characteristic is that people quite regularly synchronize their activity level with that of the other participants in a conversation. The second characteristic is that the degree of synchronization increases as the number of participants increases. Based on these microscopic ferromagnetic characteristics, a “conversation activity level” was modeled according to the Ising model. The results of a simulation of activity level based on this model well reproduce macroscopic experimental measurements of activity level. This model will give a new insight into how people interact with each other in a conversation.

  19. Human - Ecosystem Interactions: The Case of Mercury

    EPA Science Inventory

    Human and ecosystem exposure studies evaluate exposure of sensitive and vulnerable populations. We will discuss how ecosystem exposure modeling studies completed for input into the US Clean Air Mercury Rule (CAMR) to evaluate the response of aquatic ecosystems to changes in mercu...

  20. The interactive evolution of human communication systems.

    PubMed

    Fay, Nicolas; Garrod, Simon; Roberts, Leo; Swoboda, Nik

    2010-04-01

    This paper compares two explanations of the process by which human communication systems evolve: iterated learning and social collaboration. It then reports an experiment testing the social collaboration account. Participants engaged in a graphical communication task either as a member of a community, where they interacted with seven different partners drawn from the same pool, or as a member of an isolated pair, where they interacted with the same partner across the same number of games. Participants' horizontal, pair-wise interactions led "bottom up" to the creation of an effective and efficient shared sign system in the community condition. Furthermore, the community-evolved sign systems were as effective and efficient as the local sign systems developed by isolated pairs. Finally, and as predicted by a social collaboration account, and not by an iterated learning account, interaction was critical to the creation of shared sign systems, with different isolated pairs establishing different local sign systems and different communities establishing different global sign systems.

  1. Frequency interactions in human epileptic brain.

    PubMed

    Cotic, Marija; Zalay, Osbert; Valiante, Taufik; Carlen, Peter L; Bardakjian, Berj L

    2011-01-01

    We have used two algorithms, wavelet phase coherence (WPC) and modulation index (MI) analysis to study frequency interactions in the human epileptic brain. Quantitative analyses were performed on intracranial electroencephalographic (iEEG) segments from three patients with neocortical epilepsy. Interelectrode coherence was measured using WPC and intraelectrode frequency interactions were analyzed using MI. WPC was performed on electrode pairings and the temporal evolution of phase couplings in the following frequency ranges: 1-4 Hz, 4-8 Hz, 8-13 Hz, 13-30 Hz and 30-100 Hz was studied. WPC was strongest in the 1-4 Hz frequency range during both seizure and non-seizure activities; however, WPC values varied minimally between electrode pairings. The 13-30 Hz band showed the lowest WPC values during seizure activity. MI analysis yielded two prominent patterns of frequency-specific activity, during seizure and non-seizure activities, which were present across all patients.

  2. Relaxing passivity for human-robot interaction.

    SciTech Connect

    Buerger, Stephen P. (Massachusetts Institute of Technology, Cambridge, MA.); Hogan, Neville

    2007-03-01

    Robots for high-force interaction with humans face particular challenges to achieve performance and coupled stability. Because available actuators are unable to provide sufficiently high force density and low impedance, controllers for such machines often attempt to mask the robots physical dynamics, though this threatens stability. Controlling for passivity, the state-of-the-art means of ensuring coupled stability, inherently limits performance to levels that are often unacceptable. A controller that imposes passivity is compared to a controller designed by a new method that uses limited knowledge of human dynamics to improve performance. Both controllers were implemented on a testbed, and coupled stability and performance were tested. Results show that the new controller can improve both stability and performance. The different structures of the controllers yield key differences in physical behavior, and guidelines are provided to assist in choosing the appropriate approach for specific applications.

  3. Interior Design Research: A Human Ecosystem Model.

    ERIC Educational Resources Information Center

    Guerin, Denise A.

    1992-01-01

    The interior ecosystems model illustrates effects on the human organism of the interaction of the natural, behavioral, and built environment. Examples of interior lighting and household energy consumption show the model's flexibility for organizing study variables in interior design research. (SK)

  4. Interactions of human microglia cells with Japanese encephalitis virus.

    PubMed

    Lannes, Nils; Neuhaus, Viviane; Scolari, Brigitte; Kharoubi-Hess, Solange; Walch, Michael; Summerfield, Artur; Filgueira, Luis

    2017-01-14

    Japanese encephalitis virus (JEV) is a neurotropic flavivirus causing mortality and morbidity in humans. Severe Japanese encephalitis cases display strong inflammatory responses in the central nervous system and an accumulation of viral particles in specific brain regions. Microglia cells are the unique brain-resident immune cell population with potent migratory functions and have been proposed to act as a viral reservoir for JEV. Animal models suggest that the targeting of microglia by JEV is partially responsible for inflammatory reactions in the brain. Nevertheless, the interactions between human microglia and JEV are poorly documented. Using human primary microglia and a new model of human blood monocyte-derived microglia, the present study explores the interaction between human microglia and JEV as well as the role of these cells in viral transmission to susceptible cells. To achieve this work, vaccine-containing inactivated JEV and two live JEV strains were applied on human microglia. Live JEV was non-cytopathogenic to human microglia but increased levels of CCL2, CXCL9 and CXCL10 in such cultures. Furthermore, human microglia up-regulated the expression of the fraktalkine receptor CX3CR1 upon exposure to both JEV vaccine and live JEV. Although JEV vaccine enhanced MHC class II on all microglia, live JEV enhanced MHC class II mainly on CX3CR1(+) microglia cells. Importantly, human microglia supported JEV replication, but infectivity was only transmitted to neighbouring cells in a contact-dependent manner. Our findings suggest that human microglia may be a source of neuronal infection and sustain JEV brain pathogenesis.

  5. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas presentation

    EPA Science Inventory

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment int...

  6. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas presentation

    EPA Science Inventory

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment int...

  7. Scaling laws of human interaction activity.

    PubMed

    Rybski, Diego; Buldyrev, Sergey V; Havlin, Shlomo; Liljeros, Fredrik; Makse, Hernán A

    2009-08-04

    Even though people in our contemporary technological society are depending on communication, our understanding of the underlying laws of human communicational behavior continues to be poorly understood. Here we investigate the communication patterns in 2 social Internet communities in search of statistical laws in human interaction activity. This research reveals that human communication networks dynamically follow scaling laws that may also explain the observed trends in economic growth. Specifically, we identify a generalized version of Gibrat's law of social activity expressed as a scaling law between the fluctuations in the number of messages sent by members and their level of activity. Gibrat's law has been essential in understanding economic growth patterns, yet without an underlying general principle for its origin. We attribute this scaling law to long-term correlation patterns in human activity, which surprisingly span from days to the entire period of the available data of more than 1 year. Further, we provide a mathematical framework that relates the generalized version of Gibrat's law to the long-term correlated dynamics, which suggests that the same underlying mechanism could be the source of Gibrat's law in economics, ranging from large firms, research and development expenditures, gross domestic product of countries, to city population growth. These findings are also of importance for designing communication networks and for the understanding of the dynamics of social systems in which communication plays a role, such as economic markets and political systems.

  8. A hierarchical framework for understanding human-human interactions in video surveillance

    NASA Astrophysics Data System (ADS)

    Park, Sangho; Aggarwal, J. K.

    2005-01-01

    Understanding human behavior in video is essential in numerous applications including smart surveillance, video annotation/retrieval, and human-computer interaction. However, recognizing human interactions is a challenging task due to ambiguity in body articulation, variations in body size and appearance, loose clothing, mutual occlusion, and shadows. In this paper we present a framework for recognizing human actions and interactions in color video, and a hierarchical graphical model that unifies multiple-level processing in video computing: pixel level, blob level, object level, and event level. A mixture of Gaussian (MOG) model is used at the pixel level to train and classify individual pixel colors. A relaxation labeling with attribute relational graph (ARG) is used at the blob level to merge the pixels into coherent blobs and to register inter-blob relations. At the object level, the poses of individual body parts are recognized using Bayesian networks (BNs). At the event level, the actions of a single person are modeled using a dynamic Bayesian network (DBN). The results of the object-level descriptions for each person are juxtaposed along a common timeline to identify an interaction between two persons. The linguistic 'verb argument structure' is used to represent human action in terms of triplets. A meaningful semantic description in terms of is obtained. Our system achieves semantic descriptions of positive, neutral, and negative interactions between two persons including hand-shaking, standing hand-in-hand, and hugging as the positive interactions, approaching, departing, and pointing as the neutral interactions, and pushing, punching, and kicking as the negative interactions.

  9. A hierarchical framework for understanding human-human interactions in video surveillance

    NASA Astrophysics Data System (ADS)

    Park, Sangho; Aggarwal, J. K.

    2004-12-01

    Understanding human behavior in video is essential in numerous applications including smart surveillance, video annotation/retrieval, and human-computer interaction. However, recognizing human interactions is a challenging task due to ambiguity in body articulation, variations in body size and appearance, loose clothing, mutual occlusion, and shadows. In this paper we present a framework for recognizing human actions and interactions in color video, and a hierarchical graphical model that unifies multiple-level processing in video computing: pixel level, blob level, object level, and event level. A mixture of Gaussian (MOG) model is used at the pixel level to train and classify individual pixel colors. A relaxation labeling with attribute relational graph (ARG) is used at the blob level to merge the pixels into coherent blobs and to register inter-blob relations. At the object level, the poses of individual body parts are recognized using Bayesian networks (BNs). At the event level, the actions of a single person are modeled using a dynamic Bayesian network (DBN). The results of the object-level descriptions for each person are juxtaposed along a common timeline to identify an interaction between two persons. The linguistic 'verb argument structure' is used to represent human action in terms of triplets. A meaningful semantic description in terms of is obtained. Our system achieves semantic descriptions of positive, neutral, and negative interactions between two persons including hand-shaking, standing hand-in-hand, and hugging as the positive interactions, approaching, departing, and pointing as the neutral interactions, and pushing, punching, and kicking as the negative interactions.

  10. Human-Robot Interaction Directed Research Project

    NASA Technical Reports Server (NTRS)

    Sandor, Aniko; Cross, Ernest V., II; Chang, M. L.

    2014-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces and command modalities affect the human's ability to perform tasks accurately, efficiently, and effectively when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. This DRP concentrates on three areas associated with interfaces and command modalities in HRI which are applicable to NASA robot systems: 1) Video Overlays, 2) Camera Views, and 3) Command Modalities. The first study focused on video overlays that investigated how Augmented Reality (AR) symbology can be added to the human-robot interface to improve teleoperation performance. Three types of AR symbology were explored in this study, command guidance (CG), situation guidance (SG), and both (SCG). CG symbology gives operators explicit instructions on what commands to input, whereas SG symbology gives operators implicit cues so that operators can infer the input commands. The combination of CG and SG provided operators with explicit and implicit cues allowing the operator to choose which symbology to utilize. The objective of the study was to understand how AR symbology affects the human operator's ability to align a robot arm to a target using a flight stick and the ability to allocate attention between the symbology and external views of the world. The study evaluated the effects type of symbology (CG and SG) has on operator tasks performance and attention allocation during teleoperation of a robot arm. The second study expanded on the first study by evaluating the effects of the type of

  11. Prosthetic Leg Control in the Nullspace of Human Interaction

    PubMed Central

    Gregg, Robert D.; Martin, Anne E.

    2016-01-01

    Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection. PMID:27746585

  12. Human computer interaction using hand gesture.

    PubMed

    Wan, Silas; Nguyen, Hung T

    2008-01-01

    Hand gesture is a very natural form of human interaction and can be used effectively in human computer interaction (HCI). This project involves the design and implementation of a HCI using a small hand-worn wireless module with a 3-axis accelerometer as the motion sensor. The small stand-alone unit contains an accelerometer and a wireless Zigbee transceiver with microcontroller. To minimize intrusiveness to the user, the module is designed to be small (3cm by 4 cm). A time-delay neural network algorithm is developed to analyze the time series data from the 3-axis accelerometer. Power consumption is reduced by the non-continuous transmission of data and the use of low-power components, efficient algorithm and sleep mode between sampling for the wireless module. A home control interface is designed so that the user can control home appliances by moving through menus. The results demonstrate the feasibility of controlling home appliances using hand gestures and would present an opportunity for a section of the aging population and disabled people to lead a more independent life.

  13. Unsupervised Synchrony Discovery in Human Interaction

    PubMed Central

    Chu, Wen-Sheng; Zeng, Jiabei; De la Torre, Fernando; Cohn, Jeffrey F.; Messinger, Daniel S.

    2016-01-01

    People are inherently social. Social interaction plays an important and natural role in human behavior. Most computational methods focus on individuals alone rather than in social context. They also require labelled training data. We present an unsupervised approach to discover interpersonal synchrony, referred as to two or more persons preforming common actions in overlapping video frames or segments. For computational efficiency, we develop a branch-and-bound (B&B) approach that affords exhaustive search while guaranteeing a globally optimal solution. The proposed method is entirely general. It takes from two or more videos any multi-dimensional signal that can be represented as a histogram. We derive three novel bounding functions and provide efficient extensions, including multi-synchrony detection and accelerated search, using a warm-start strategy and parallelism. We evaluate the effectiveness of our approach in multiple databases, including human actions using the CMU Mocap dataset [1], spontaneous facial behaviors using group-formation task dataset [37] and parent-infant interaction dataset [28]. PMID:27346988

  14. Human-Robot Interaction Directed Research Project

    NASA Technical Reports Server (NTRS)

    Sandor, Aniko; Cross, Ernest V., II; Chang, Mai Lee

    2014-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces and command modalities affect the human's ability to perform tasks accurately, efficiently, and effectively when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. This DRP concentrates on three areas associated with interfaces and command modalities in HRI which are applicable to NASA robot systems: 1) Video Overlays, 2) Camera Views, and 3) Command Modalities. The first study focused on video overlays that investigated how Augmented Reality (AR) symbology can be added to the human-robot interface to improve teleoperation performance. Three types of AR symbology were explored in this study, command guidance (CG), situation guidance (SG), and both (SCG). CG symbology gives operators explicit instructions on what commands to input, whereas SG symbology gives operators implicit cues so that operators can infer the input commands. The combination of CG and SG provided operators with explicit and implicit cues allowing the operator to choose which symbology to utilize. The objective of the study was to understand how AR symbology affects the human operator's ability to align a robot arm to a target using a flight stick and the ability to allocate attention between the symbology and external views of the world. The study evaluated the effects type of symbology (CG and SG) has on operator tasks performance and attention allocation during teleoperation of a robot arm. The second study expanded on the first study by evaluating the effects of the type of

  15. A behavioral biometric system based on human-computer interaction

    NASA Astrophysics Data System (ADS)

    Gamboa, Hugo; Fred, Ana

    2004-08-01

    In this paper we describe a new behavioural biometric technique based on human computer interaction. We developed a system that captures the user interaction via a pointing device, and uses this behavioural information to verify the identity of an individual. Using statistical pattern recognition techniques, we developed a sequential classifier that processes user interaction, according to which the user identity is considered genuine if a predefined accuracy level is achieved, and the user is classified as an impostor otherwise. Two statistical models for the features were tested, namely Parzen density estimation and a unimodal distribution. The system was tested with different numbers of users in order to evaluate the scalability of the proposal. Experimental results show that the normal user interaction with the computer via a pointing device entails behavioural information with discriminating power, that can be explored for identity authentication.

  16. Interaction between bioactive glasses and human dentin.

    PubMed

    Efflandt, S E; Magne, P; Douglas, W H; Francis, L F

    2002-06-01

    This study explores the interaction between bioactive glasses and dentin from extracted human teeth in simulated oral conditions. Bioactive glasses in the Na(2)O-CaO-P(2)O(5)-SiO(2) and MgO-CaO-P(2)O(5)-SiO(2) systems were prepared as polished disks. Teeth were prepared by grinding to expose dentin and etching with phosphoric acid. A layer of saliva was placed between the two, and the pair was secured with an elastic band and immersed in saliva at 37 degrees C for 5, 21 or 42 days. The bioactive glasses adhered to dentin, while controls showed no such interaction. A continuous interface between the bioactive glass and dentin was imaged using cryogenic-scanning electron microscopy (SEM). However, after alcohol dehydration and critical point drying, fracture occurred due to stresses from dentin shrinkage. SEM investigations showed a microstructurally different material at the fractured interface. Chemical analyses revealed that ions from the glass penetrated into the dentin and that the surface of the glass in contact with the dentin was modified. Microdiffractometry showed the presence of apatite at the interface. Bonding appears to be due to an affinity of collagen for the glass surface and chemical interaction between the dentin and glass, leading to apatite formation at the interface.

  17. Modelling Positron Interactions with Matter

    NASA Astrophysics Data System (ADS)

    Garcia, G.; Petrovic, Z.; White, R.; Buckman, S.

    2011-05-01

    In this work we link fundamental measurements of positron interactions with biomolecules, with the development of computer codes for positron transport and track structure calculations. We model positron transport in a medium from a knowledge of the fundamental scattering cross section for the atoms and molecules comprising the medium, combined with a transport analysis based on statistical mechanics and Monte-Carlo techniques. The accurate knowledge of the scattering is most important at low energies, a few tens of electron volts or less. The ultimate goal of this work is to do this in soft condensed matter, with a view to ultimately developing a dosimetry model for Positron Emission Tomography (PET). The high-energy positrons first emitted by a radionuclide in PET may well be described by standard formulas for energy loss of charged particles in matter, but it is incorrect to extrapolate these formulas to low energies. Likewise, using electron cross-sections to model positron transport at these low energies has been shown to be in serious error due to the effects of positronium formation. Work was supported by the Australian Research Council, the Serbian Government, and the Ministerio de Ciencia e Innovación, Spain.

  18. Interaction of Jatrorrhizine with Human Gamma Globulin in membrane mimetic environments: Probing of the binding mechanism and binding site by spectroscopic and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Ying, Li; Chao, Wang; Guanghua, Lu

    2010-09-01

    The interaction between Jatrorrhizine and Human Gamma Globulin (HGG) in AOT/isooctane/water microemulsions was studied by using fluorescence quenching, UV absorption spectroscopy, circular dischroism (CD) spectroscopy and dynamic light scattering (DLS). Fluorescence data in water-surfactant molar ratio ( ω0) 25 microemulsions revealed the presence of the binding site of Jatrorrhizine on HGG and its binding constants at four temperatures were obtained. The affinities in microemulsions were similar to that in buffer solution. The alterations of ΗGG secondary structure in the microemulsions in the absence and presence of Jatrorrhizine compared with the free form of HGG in buffer were analyzed by CD spectroscopy. In addition, the DLS data suggested that HGG may locate inside the microemulsion and Jatrorrhizine could interact with them. Furthermore, the thermodynamic functions, i.e. standard enthalpy ( ΔH0) and standard entropy ( ΔS0) for the reaction were also calculated, according to Van't Hoff equation. These data showed that hydrophobic and electrostatic interaction played the main role in the binding of Jatrorrhizine to HGG.

  19. Optimized Assistive Human-Robot Interaction Using Reinforcement Learning.

    PubMed

    Modares, Hamidreza; Ranatunga, Isura; Lewis, Frank L; Popa, Dan O

    2016-03-01

    An intelligent human-robot interaction (HRI) system with adjustable robot behavior is presented. The proposed HRI system assists the human operator to perform a given task with minimum workload demands and optimizes the overall human-robot system performance. Motivated by human factor studies, the presented control structure consists of two control loops. First, a robot-specific neuro-adaptive controller is designed in the inner loop to make the unknown nonlinear robot behave like a prescribed robot impedance model as perceived by a human operator. In contrast to existing neural network and adaptive impedance-based control methods, no information of the task performance or the prescribed robot impedance model parameters is required in the inner loop. Then, a task-specific outer-loop controller is designed to find the optimal parameters of the prescribed robot impedance model to adjust the robot's dynamics to the operator skills and minimize the tracking error. The outer loop includes the human operator, the robot, and the task performance details. The problem of finding the optimal parameters of the prescribed robot impedance model is transformed into a linear quadratic regulator (LQR) problem which minimizes the human effort and optimizes the closed-loop behavior of the HRI system for a given task. To obviate the requirement of the knowledge of the human model, integral reinforcement learning is used to solve the given LQR problem. Simulation results on an x - y table and a robot arm, and experimental implementation results on a PR2 robot confirm the suitability of the proposed method.

  20. A molecular model for the interaction between vorozole and other non-steroidal inhibitors and human cytochrome P450 19 (P450 aromatase).

    PubMed

    Koymans, L M; Moereels, H; Vanden Bossche, H

    1995-06-01

    In a previous study (Vanden Bossche et al., Breast Cancer Res. Treat. 30 (1994) 43) the interaction between (+)-S-vorozole and the I-helix of cytochrome P450 19 (P450 aromatase) has been reported. In the present study we extended the "I-helix model" by incorporating the C-terminus of P450 aromatase. The crystal structures of P450 101 (P450 cam), 102 (P450 BM-3) and 108 (P450 terp) reveal that the C-terminus is structurally conserved and forms part of their respective substrate binding pocket. Furthermore, the present study is extended to the interaction between P450 aromatase and its natural substrate androstenedione and the non-steroidal inhibitors (-)-R-vorozole, (-)-S-fadrozole, R-liarozole and (-)-R-aminoglutethimide. It is found that (+)-S-vorozole, (-)-S-fadrozole and R-liarozole bind in a comparable way to P450 aromatase and interact with both the I-helix (Glu302 and Asp309) and C-terminus (Ser478 and His480). The weak activity of (-)-R-aminoglutethimide might be attributed to a lack of interaction with the C-terminus.

  1. Loving Machines: Theorizing Human and Sociable-Technology Interaction

    NASA Astrophysics Data System (ADS)

    Shaw-Garlock, Glenda

    Today, human and sociable-technology interaction is a contested site of inquiry. Some regard social robots as an innovative medium of communication that offer new avenues for expression, communication, and interaction. Other others question the moral veracity of human-robot relationships, suggesting that such associations risk psychological impoverishment. What seems clear is that the emergence of social robots in everyday life will alter the nature of social interaction, bringing with it a need for new theories to understand the shifting terrain between humans and machines. This work provides a historical context for human and sociable robot interaction. Current research related to human-sociable-technology interaction is considered in relation to arguments that confront a humanist view that confine 'technological things' to the nonhuman side of the human/nonhuman binary relation. Finally, it recommends a theoretical approach for the study of human and sociable-technology interaction that accommodates increasingly personal relations between human and nonhuman technologies.

  2. User Interaction Modeling and Profile Extraction in Interactive Systems: A Groupware Application Case Study.

    PubMed

    Tîrnăucă, Cristina; Duque, Rafael; Montaña, José L

    2017-07-20

    A relevant goal in human-computer interaction is to produce applications that are easy to use and well-adjusted to their users' needs. To address this problem it is important to know how users interact with the system. This work constitutes a methodological contribution capable of identifying the context of use in which users perform interactions with a groupware application (synchronous or asynchronous) and provides, using machine learning techniques, generative models of how users behave. Additionally, these models are transformed into a text that describes in natural language the main characteristics of the interaction of the users with the system.

  3. A three-dimensional model of the human blood-brain barrier to analyse the transport of nanoparticles and astrocyte/endothelial interactions

    PubMed Central

    Sreekanthreddy, Peddagangannagari; Gromnicova, Radka; Davies, Heather; Phillips, James; Romero, Ignacio A.; Male, David

    2016-01-01

    The aim of this study was to develop a three-dimensional (3D) model of the human blood-brain barrier in vitro, which mimics the cellular architecture of the CNS and could be used to analyse the delivery of nanoparticles to cells of the CNS. The model includes human astrocytes set in a collagen gel, which is overlaid by a monolayer of human brain endothelium (hCMEC/D3 cell line). The model was characterised by transmission electron microscopy (TEM), immunofluorescence microscopy and flow cytometry. A collagenase digestion method could recover the two cell types separately at 92-96% purity.  Astrocytes grown in the gel matrix do not divide and they have reduced expression of aquaporin-4 and the endothelin receptor, type B compared to two-dimensional cultures, but maintain their expression of glial fibrillary acidic protein. The effects of conditioned media from these astrocytes on the barrier phenotype of the endothelium was compared with media from astrocytes grown conventionally on a two-dimensional (2D) substratum. Both induce the expression of tight junction proteins zonula occludens-1 and claudin-5 in hCMEC/D3 cells, but there was no difference between the induced expression levels by the two media. The model has been used to assess the transport of glucose-coated 4nm gold nanoparticles and for leukocyte migration. TEM was used to trace and quantitate the movement of the nanoparticles across the endothelium and into the astrocytes. This blood-brain barrier model is very suitable for assessing delivery of nanoparticles and larger biomolecules to cells of the CNS, following transport across the endothelium. PMID:26870320

  4. Analyzing Human-Landscape Interactions: Tools That Integrate

    NASA Astrophysics Data System (ADS)

    Zvoleff, Alex; An, Li

    2014-01-01

    Humans have transformed much of Earth's land surface, giving rise to loss of biodiversity, climate change, and a host of other environmental issues that are affecting human and biophysical systems in unexpected ways. To confront these problems, environmental managers must consider human and landscape systems in integrated ways. This means making use of data obtained from a broad range of methods (e.g., sensors, surveys), while taking into account new findings from the social and biophysical science literatures. New integrative methods (including data fusion, simulation modeling, and participatory approaches) have emerged in recent years to address these challenges, and to allow analysts to provide information that links qualitative and quantitative elements for policymakers. This paper brings attention to these emergent tools while providing an overview of the tools currently in use for analysis of human-landscape interactions. Analysts are now faced with a staggering array of approaches in the human-landscape literature—in an attempt to bring increased clarity to the field, we identify the relative strengths of each tool, and provide guidance to analysts on the areas to which each tool is best applied. We discuss four broad categories of tools: statistical methods (including survival analysis, multi-level modeling, and Bayesian approaches), GIS and spatial analysis methods, simulation approaches (including cellular automata, agent-based modeling, and participatory modeling), and mixed-method techniques (such as alternative futures modeling and integrated assessment). For each tool, we offer an example from the literature of its application in human-landscape research. Among these tools, participatory approaches are gaining prominence for analysts to make the broadest possible array of information available to researchers, environmental managers, and policymakers. Further development of new approaches of data fusion and integration across sites or disciplines

  5. Analyzing human-landscape interactions: tools that integrate.

    PubMed

    Zvoleff, Alex; An, Li

    2014-01-01

    Humans have transformed much of Earth's land surface, giving rise to loss of biodiversity, climate change, and a host of other environmental issues that are affecting human and biophysical systems in unexpected ways. To confront these problems, environmental managers must consider human and landscape systems in integrated ways. This means making use of data obtained from a broad range of methods (e.g., sensors, surveys), while taking into account new findings from the social and biophysical science literatures. New integrative methods (including data fusion, simulation modeling, and participatory approaches) have emerged in recent years to address these challenges, and to allow analysts to provide information that links qualitative and quantitative elements for policymakers. This paper brings attention to these emergent tools while providing an overview of the tools currently in use for analysis of human-landscape interactions. Analysts are now faced with a staggering array of approaches in the human-landscape literature--in an attempt to bring increased clarity to the field, we identify the relative strengths of each tool, and provide guidance to analysts on the areas to which each tool is best applied. We discuss four broad categories of tools: statistical methods (including survival analysis, multi-level modeling, and Bayesian approaches), GIS and spatial analysis methods, simulation approaches (including cellular automata, agent-based modeling, and participatory modeling), and mixed-method techniques (such as alternative futures modeling and integrated assessment). For each tool, we offer an example from the literature of its application in human-landscape research. Among these tools, participatory approaches are gaining prominence for analysts to make the broadest possible array of information available to researchers, environmental managers, and policymakers. Further development of new approaches of data fusion and integration across sites or disciplines pose

  6. Interaction of mycotoxin zearalenone with human serum albumin.

    PubMed

    Poór, Miklós; Kunsági-Máté, Sándor; Bálint, Mónika; Hetényi, Csaba; Gerner, Zsófia; Lemli, Beáta

    2017-03-27

    Zearalenone (ZEN) is a mycotoxin produced mainly by Fusarium species. Fungal contamination of cereals and plants can result in the formation of ZEN, leading to its presence in different foods, animal feeds, and drinks. Because ZEN is an endocrine disruptor, it causes reproductive disorders in farm animals and hyperoestrogenic syndromes in humans. Despite toxicokinetic properties of ZEN were studied in more species, we have no information regarding the interaction of ZEN with serum albumin. Since albumin commonly plays an important role in the toxicokinetics of different toxins, interaction of ZEN with albumin has of high biological importance. Therefore the interaction of ZEN with human serum albumin (HSA) was investigated using spectroscopic methods, ultrafiltration, and molecular modeling studies. Fluorescence spectroscopic studies demonstrate that ZEN forms complex with HSA. Binding constant (K) of ZEN-HSA complex was quantified with fluorescence quenching technique. The determined binding constant (logK=5.1) reflects the strong interaction of ZEN with albumin suggesting the potential biological importance of ZEN-HSA complex formation. Based on the results of the investigations with site markers as well as docking studies, ZEN occupies a non-conventional binding site on HSA. Considering the above listed observations, we should keep in mind this interaction if we would like to precisely understand the toxicokinetic behavior of ZEN.

  7. Interactions between human granulocytes and Blastomyces dermatitidis.

    PubMed Central

    Sixbey, J W; Fields, B T; Sun, C N; Clark, R A; Nolan, C M

    1979-01-01

    We studied interactions in vitro between human granulocytes and the yeast-like form of Blastomyces dermatitidis, because granulocytes are prominent in the host response to systemic blastomycosis. In Boyden chamber assays, broth culture filtrates of B. dermatitidis contained levels of granulocyte chemotactic activity that were significantly higher than those present in similar culture filtrates of Histoplasma capsulatum and Cryptococcus neoformans, two fungi that characteristically do not elicit granulocytes in infected tissues. Microscopic study, including electron microscopy, demonstrated that granulocytes phagocytosed B. dermatitidis promptly and efficiently. Moreover, granulocytes emitted light (chemiluminescence) at a brisk rate during phagocytosis of B. dermatitidis, indicating activation of intracellular metabolic pathways. However, fungicidal assay showed that granulocytes (1:1 cell-yeast ratio, 10% serum) killed only 29% of the B. dermatitidis inoculum during 3 h of incubation. Taken together, these findings suggest that there is disparity between phagocytosis and intracellular killing of B. dermatitidis by human granulocytes, perhaps because of resistance of this fungus to granulocyte microbicidal mechanisms. PMID:422234

  8. Dynamic In Vitro Models of the Human Gastrointestinal Tract as Relevant Tools to Assess the Survival of Probiotic Strains and Their Interactions with Gut Microbiota

    PubMed Central

    Cordonnier, Charlotte; Thévenot, Jonathan; Etienne-Mesmin, Lucie; Denis, Sylvain; Alric, Monique; Livrelli, Valérie; Blanquet-Diot, Stéphanie

    2015-01-01

    The beneficial effects of probiotics are conditioned by their survival during passage through the human gastrointestinal tract and their ability to favorably influence gut microbiota. The main objective of this study was to use dynamic in vitro models of the human digestive tract to investigate the effect of fasted or fed state on the survival kinetics of the new probiotic Saccharomyces cerevisiae strain CNCM I-3856 and to assess its influence on intestinal microbiota composition and activity. The probiotic yeast showed a high survival rate in the upper gastrointestinal tract whatever the route of admistration, i.e., within a glass of water or a Western-type meal. S. cerevisiae CNCM I-3856 was more sensitive to colonic conditions, as the strain was not able to colonize within the bioreactor despite a twice daily administration. The main bacterial populations of the gut microbiota, as well as the production of short chain fatty acids were not influenced by the probiotic treatment. However, the effect of the probiotic on the gut microbiota was found to be individual dependent. This study shows that dynamic in vitro models can be advantageously used to provide useful insight into the behavior of probiotic strains in the human digestive environment. PMID:27682114

  9. Deformable human body model development

    SciTech Connect

    Wray, W.O.; Aida, T.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). A Deformable Human Body Model (DHBM) capable of simulating a wide variety of deformation interactions between man and his environment has been developed. The model was intended to have applications in automobile safety analysis, soldier survivability studies and assistive technology development for the disabled. To date, we have demonstrated the utility of the DHBM in automobile safety analysis and are currently engaged in discussions with the U.S. military involving two additional applications. More specifically, the DHBM has been incorporated into a Virtual Safety Lab (VSL) for automobile design under contract to General Motors Corporation. Furthermore, we have won $1.8M in funding from the U.S. Army Medical Research and Material Command for development of a noninvasive intracranial pressure measurement system. The proposed research makes use of the detailed head model that is a component of the DHBM; the project duration is three years. In addition, we have been contacted by the Air Force Armstrong Aerospace Medical Research Laboratory concerning possible use of the DHBM in analyzing the loads and injury potential to pilots upon ejection from military aircraft. Current discussions with Armstrong involve possible LANL participation in a comparison between DHBM and the Air Force Articulated Total Body (ATB) model that is the current military standard.

  10. Modeling human-environmental systems

    Treesearch

    Morgan Grove; Charlie Schweik; Tom Evans; Glen Green

    2002-01-01

    This chapter focuses on the integration and development of environmental models that include human decision making. While many methodological and technical issues are common to all types of environmental models, our goal is to highlight the unique characteristics that need to be considered when modeling human-environmental dynamics and to identify future directions for...

  11. On the Rhetorical Contract in Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Wenger, Michael J.

    1991-01-01

    An exploration of the rhetorical contract--i.e., the expectations for appropriate interaction--as it develops in human-computer interaction revealed that direct manipulation interfaces were more likely to establish social expectations. Study results suggest that the social nature of human-computer interactions can be examined with reference to the…

  12. HIV-1, human interaction database: current status and new features.

    PubMed

    Ako-Adjei, Danso; Fu, William; Wallin, Craig; Katz, Kenneth S; Song, Guangfeng; Darji, Dakshesh; Brister, J Rodney; Ptak, Roger G; Pruitt, Kim D

    2015-01-01

    The 'Human Immunodeficiency Virus Type 1 (HIV-1), Human Interaction Database', available through the National Library of Medicine at http://www.ncbi.nlm.nih.gov/genome/viruses/retroviruses/hiv-1/interactions, serves the scientific community exploring the discovery of novel HIV vaccine candidates and therapeutic targets. Each HIV-1 human protein interaction can be retrieved without restriction by web-based downloads and ftp protocols and includes: Reference Sequence (RefSeq) protein accession numbers, National Center for Biotechnology Information Gene identification numbers, brief descriptions of the interactions, searchable keywords for interactions and PubMed identification numbers (PMIDs) of journal articles describing the interactions. In addition to specific HIV-1 protein-human protein interactions, included are interaction effects upon HIV-1 replication resulting when individual human gene expression is blocked using siRNA. A total of 3142 human genes are described participating in 12,786 protein-protein interactions, along with 1316 replication interactions described for each of 1250 human genes identified using small interfering RNA (siRNA). Together the data identifies 4006 human genes involved in 14,102 interactions. With the inclusion of siRNA interactions we introduce a redesigned web interface to enhance viewing, filtering and downloading of the combined data set.

  13. Soil and Human Interactions in Maya Wetlands

    NASA Astrophysics Data System (ADS)

    Beach, Timothy; Luzzadder-Beach, Sheryl

    2013-04-01

    Since the early 1990s, we have studied Maya interaction with soils in Mexico, Belize, Guatemala, and elsewhere. We studied upland and lowland soils, but here we focus on seasonal or 'Bajo' wetlands and perennial wetlands for different reasons. Around the bajos, the ancient Maya focused on intensive agriculture and habitation despite the difficulties their Vertisol soils posed. For the perennial wetlands, small populations spread diffusely through Mollisol and Histisol landscapes with large scale, intensive agro-ecosystems. These wetlands also represent important repositories for both environmental change and how humans responded in situ to environmental changes. Work analyzing bajo soils has recorded significant diversity but the soil and sediment record shows two main eras of soil instability: the Pleistocene-Holocene transition as rainfall fluctuated and increased and tropical forest pulsed through the region, and the Maya Preclassic to Classic 3000 to 1000 BP as deforestation, land use intensity, and drying waxed and waned. The ancient Maya adapted their bajo soil ecosystems successfully through agro-engineering but they also withdrew in many important places in the Late Preclassic about 2000 BP and Terminal Classic about 1200 BP. We continue to study and debate the importance of perennial wetland agro-ecosystems, but it is now clear that Maya interaction with these soil landscapes was significant and multifaceted. Based on soil excavation and coring with a broad toolkit of soil stratigraphy, chemistry, and paleoecology from 2001 to 2013, our results show the ancient Maya interacted with their wetland soils to maintain cropland for maize, tree crops, arrow root, and cassava against relative sea level rise, increased flooding, and aggradation by gypsum precipitation and sedimentation. We have studied these interactions across an area of 2000 km2 in Northern Belize to understand how Maya response varied and how these soil environments varied over time and distance

  14. Kinematic design to improve ergonomics in human machine interaction.

    PubMed

    Schiele, André; van der Helm, Frans C T

    2006-12-01

    This paper introduces a novel kinematic design paradigm for ergonomic human machine interaction. Goals for optimal design are formulated generically and applied to the mechanical design of an upper-arm exoskeleton. A nine degree-of-freedom (DOF) model of the human arm kinematics is presented and used to develop, test, and optimize the kinematic structure of an human arm interfacing exoskeleton. The resulting device can interact with an unprecedented portion of the natural limb workspace, including motions in the shoulder-girdle, shoulder, elbow, and the wrist. The exoskeleton does not require alignment to the human joint axes, yet is able to actuate each DOF of our redundant limb unambiguously and without reaching into singularities. The device is comfortable to wear and does not create residual forces if misalignments exist. Implemented in a rehabilitation robot, the design features of the exoskeleton could enable longer lasting training sessions, training of fully natural tasks such as activities of daily living and shorter dress-on and dress-off times. Results from inter-subject experiments with a prototype are presented, that verify usability over the entire workspace of the human arm, including shoulder and shoulder girdle.

  15. ISS Plasma Interaction: Measurements and Modeling

    NASA Technical Reports Server (NTRS)

    Barsamian, H.; Mikatarian, R.; Alred, J.; Minow, J.; Koontz, S.

    2004-01-01

    Ionospheric plasma interaction effects on the International Space Station are discussed in the following paper. The large structure and high voltage arrays of the ISS represent a complex system interacting with LEO plasma. Discharge current measurements made by the Plasma Contactor Units and potential measurements made by the Floating Potential Probe delineate charging and magnetic induction effects on the ISS. Based on theoretical and physical understanding of the interaction phenomena, a model of ISS plasma interaction has been developed. The model includes magnetic induction effects, interaction of the high voltage solar arrays with ionospheric plasma, and accounts for other conductive areas on the ISS. Based on these phenomena, the Plasma Interaction Model has been developed. Limited verification of the model has been performed by comparison of Floating Potential Probe measurement data to simulations. The ISS plasma interaction model will be further tested and verified as measurements from the Floating Potential Measurement Unit become available, and construction of the ISS continues.

  16. Formal Aspects of Human-Automation Interaction

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Heymann, Michael; Moodi, Michael; Remington, Roger (Technical Monitor)

    1998-01-01

    While new versions of automated control systems such as flight guidance systems are introduced at a rapid pace, it is widely recognized that user interaction with these machines is increasingly problematic. One cause for this difficulty that is commonly cited in the literature, is the discrepancy between the machine's behavior and the operator's (e.g., pilot) expectations. This paper discusses a formal approach to the analysis of operator's interaction with complex automated control systems. We focus attention on the issue of interface correctness; that is, on the question whether the display provides adequate information about the machine's configurations (states, modes, and associated parameters) and transitions, so as to enable the operator to successfully perform the specified set of tasks. To perform the analysis several assumptions are made: (1) A complete formal model of the machine's behavior is available (e.g., as a state transition system, or as a hybrid-machine); (2) A specification of operator's tasks is available and can be formally described (e.g., the reliable and predictable transition between activities involved in executing a climb to a new altitude); (3) The pilot is well trained and has a correct 'mental' model of the machine's response-map. By 'comparing' the machine's model with the set of operator's tasks we formally (i.e., mathematically) evaluate two questions: 1) does the machine's output interface (display) enable the operator to determine, unambiguously, what the current configuration (e.g., mode) of the machine is, and 2) does the display enable the operator to determine, unambiguously, what the next configuration of the machine will be, in response to a specified interaction by the operator (e.g., engaging a mode or changing a parameter such as a speed or target altitude). This paper describes a methodology for conducting such an evaluation using examples from automated flight control systems of modem 'glass cockpit' jetliners

  17. Interactive Model-Centric Systems Engineering (IMCSE) Phase 1

    DTIC Science & Technology

    2014-09-30

    point in time by a single decision maker; multi- sensory representations may allow for some loosening of this constraint and improve human -model...34Point" Futures (l) and Multi-Epoch Analysis (r) ....................... 40 Figure 10. Interactive Epoch-Era Analysis leverages humans -in-the-loop...develop systems, it is important to improve human and technology integration to make trades and decide on what is most effective given the present

  18. Humanized chimeric uPA mouse model for the study of hepatitis B and D virus interactions and preclinical drug evaluation.

    PubMed

    Lütgehetmann, Marc; Mancke, Lida V; Volz, Tassilo; Helbig, Martina; Allweiss, Lena; Bornscheuer, Till; Pollok, Joerg M; Lohse, Ansgar W; Petersen, J; Urban, Stephan; Dandri, Maura

    2012-03-01

    No specific drugs are currently available against hepatitis delta virus (HDV), a defective virus leading to the most severe form of chronic viral hepatitis in man. The lack of convenient HDV infection models has hampered the development of effective therapeutics. In this study, naïve and hepatitis B virus (HBV) chronically infected humanized uPA/SCID mice were employed to establish a small animal model of HBV/HDV coinfection and superinfection. For preclinical antiviral drug evaluation, the GMP version of the myristoylated preS-peptide (Myrcludex-B), a lipopeptide derived from the pre-S1 domain of the HBV envelope, was applied to prevent de novo HBV/HDV coinfection in vivo. Virological parameters were determined at serological and intrahepatic level both by real-time polymerase chain reaction (PCR) and by immunohistochemistry. Establishment of HDV infection was highly efficient in both HBV-infected and naïve chimeric mice with HDV titers rising up to 1 × 10E9 copies/mL. Notably, HDV superinfection led to a median 0.6log reduction of HBV viremia, which although not statistically significant suggests that HDV may hinder HBV replication. In the setting of HBV/HDV simultaneous infection, a majority of human hepatocytes stained HDAg-positive long before HBV spreading was completed, confirming that HDV can replicate intrahepatically also in the absence of HBV infection. Furthermore, the increase of HBV viremia and intrahepatic cccDNA loads was significantly slower than in HBV mono-infected mice. Treatment with the HBV entry inhibitor Myrcludex-B, efficiently hindered the establishment of HDV infection in vivo. We established an efficient model of HBV/HDV infection to exploit mechanisms of viral interference in human hepatocytes and to test the efficacy of an HDV-entry inhibitor in vivo. Copyright © 2011 American Association for the Study of Liver Diseases.

  19. Intelligent Support for Human Computer Interaction and Decision-Making in Distribution Planning and Scheduling Systems

    DTIC Science & Technology

    1993-02-28

    transportation planning in the Army. The work addressed frameworks and tools for human - computer interaction in systems involving large amounts of...diverse information and development of decision making models. Research on human - computer interaction involved: (1) dynamic display generation for

  20. Past Holocene detritism quantification and modeling from lacustrine archives in order to deconvoluate human-climate interactions on natural ecosystem over long time-scale

    NASA Astrophysics Data System (ADS)

    Simonneau, Anaëlle; Chapron, Emmanuel; Di Giovanni, Christian; Galop, Didier; Darboux, Frédéric

    2014-05-01

    Water budget is one of the main challenges to paleoclimate researchers in relation to present-day global warming and its consequences for human societies. Associated soil degradation and erosion are thereby becoming a major concern in many parts of the world and more particularly in the Alps. Moreover, humans are considered as geomorphologic agents since few thousand years and it is now recognized that such an impact on natural ecosystem profoundly modified soils properties as well as aquatic ecosystems dynamics over long-term periods. The quantification of such inference over long time-scale is therefore essential to establish new policies to reduce mechanic soil erosion, which is one of the dominant processes in Europe, and anticipate the potential consequences of future climate change on hydric erosion. The mechanical erosion of continental surfaces results from climatic forcing, but can be amplified by the anthropogenic one. We therefore suggest that quantifying and modelling soil erosion processes within comparable Holocene lacustrine archives, allows to estimate and date which and when past human activities have had an impact on soil fluxes over the last 10000 years. Based on the present-day geomorphology of the surrounding watershed and the evolution of the vegetation cover during the Holocene, we develop an interdisciplinary approach combining quantitative organic petrography (i.e. optical characterization and quantification of soil particles within lake sediments) with high-resolution seismic profiling, age-depth models on lacustrine sediment cores and soil erosional susceptibility modeling, in order to estimate the annual volume of soil eroded over the last 10000 years, and in fine to quantify the volume of human-induced soil erosion during the Holocene period. This method is applied to close but contrasted mountainous lacustrine environments from the western French Alps: lakes Blanc Huez and Paladru, sensitive to same climatic influences but where past

  1. Visual exploration and analysis of human-robot interaction rules

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Boyles, Michael J.

    2013-01-01

    We present a novel interaction paradigm for the visual exploration, manipulation and analysis of human-robot interaction (HRI) rules; our development is implemented using a visual programming interface and exploits key techniques drawn from both information visualization and visual data mining to facilitate the interaction design and knowledge discovery process. HRI is often concerned with manipulations of multi-modal signals, events, and commands that form various kinds of interaction rules. Depicting, manipulating and sharing such design-level information is a compelling challenge. Furthermore, the closed loop between HRI programming and knowledge discovery from empirical data is a relatively long cycle. This, in turn, makes design-level verification nearly impossible to perform in an earlier phase. In our work, we exploit a drag-and-drop user interface and visual languages to support depicting responsive behaviors from social participants when they interact with their partners. For our principal test case of gaze-contingent HRI interfaces, this permits us to program and debug the robots' responsive behaviors through a graphical data-flow chart editor. We exploit additional program manipulation interfaces to provide still further improvement to our programming experience: by simulating the interaction dynamics between a human and a robot behavior model, we allow the researchers to generate, trace and study the perception-action dynamics with a social interaction simulation to verify and refine their designs. Finally, we extend our visual manipulation environment with a visual data-mining tool that allows the user to investigate interesting phenomena such as joint attention and sequential behavioral patterns from multiple multi-modal data streams. We have created instances of HRI interfaces to evaluate and refine our development paradigm. As far as we are aware, this paper reports the first program manipulation paradigm that integrates visual programming

  2. Method and apparatus for modeling interactions

    DOEpatents

    Xavier, Patrick G.

    2002-01-01

    The present invention provides a method and apparatus for modeling interactions that overcomes drawbacks. The method of the present invention comprises representing two bodies undergoing translations by two swept volume representations. Interactions such as nearest approach and collision can be modeled based on the swept body representations. The present invention is more robust and allows faster modeling than previous methods.

  3. Molecular modeling of NK-CT1, from Indian monocellate cobra (Naja kaouthia) and its docking interaction with human DNA topoisomerase II alpha

    PubMed Central

    Bandopadhyay, Pathikrit; Halder, Soma; Sarkar, Mrinmoy; Kumar Bhunia, Sujay; Dey, Sananda; Gomes, Antony; Giri, Biplab

    2016-01-01

    A 6.76 kDa molecular weight cardio and cytotoxic protein of 60 amino acids in length called NK-CT1, was purified from the venom of Indian monocellate cobra (Naja kaouthia) by ion-exchange chromatography and HPLC as described in our earlier report. Therefore it is of interest to utlize the sequence of NK-CT1 for further functional inference using molecular modeling and docking. Thus homology model of NK-CT1 is described in this report. The anti-proliferative activity of the protein, binding with human DNA topoisomerase-II alpha was demonstrated using docking data with AUTODOCK and AUTODOCK MGL tools. Data shows that M26, V27 and S28 of NK-CT1 is in close contact with the nucleotides of the oligonucleotide, bound with topoisomerase-II alpha complex. PMID:28149043

  4. Evaluation of a computerized aid for creating human behavioral representations of human-computer interaction.

    PubMed

    Williams, Kent E; Voigt, Jeffrey R

    2004-01-01

    The research reported herein presents the results of an empirical evaluation that focused on the accuracy and reliability of cognitive models created using a computerized tool: the cognitive analysis tool for human-computer interaction (CAT-HCI). A sample of participants, expert in interacting with a newly developed tactical display for the U.S. Army's Bradley Fighting Vehicle, individually modeled their knowledge of 4 specific tasks employing the CAT-HCI tool. Measures of the accuracy and consistency of task models created by these task domain experts using the tool were compared with task models created by a double expert. The findings indicated a high degree of consistency and accuracy between the different "single experts" in the task domain in terms of the resultant models generated using the tool. Actual or potential applications of this research include assessing human-computer interaction complexity, determining the productivity of human-computer interfaces, and analyzing an interface design to determine whether methods can be automated.

  5. Homo-timeric structural model of human microsomal prostaglandin E synthase-1 and characterization of its substrate/inhibitor binding interactions

    NASA Astrophysics Data System (ADS)

    Xing, Li; Kurumbail, Ravi G.; Frazier, Ronald B.; Davies, Michael S.; Fujiwara, Hideji; Weinberg, Robin A.; Gierse, James K.; Caspers, Nicole; Carter, Jeffrey S.; McDonald, Joseph J.; Moore, William M.; Vazquez, Michael L.

    2009-01-01

    Inducible, microsomal prostaglandin E synthase 1 (mPGES-1), the terminal enzyme in the prostaglandin (PG) biosynthetic pathway, constitutes a promising therapeutic target for the development of new anti-inflammatory drugs. To elucidate structure-function relationships and to enable structure-based design, an mPGES-1 homology model was developed using the three-dimensional structure of the closest homologue of the MAPEG family (Membrane Associated Proteins in Eicosanoid and Glutathione metabolism), mGST-1. The ensuing model of mPGES-1 is a homo-trimer, with each monomer consisting of four membrane-spanning segments. Extensive structure refinement revealed an inter-monomer salt bridge (K26-E77) as well as inter-helical interactions within each monomer, including polar hydrogen bonds (e.g. T78-R110-T129) and hydrophobic π-stacking (F82-F103-F106), all contributing to the overall stability of the homo-trimer of mPGES-1. Catalytic co-factor glutathione (GSH) was docked into the mPGES-1 model by flexible optimization of both the ligand and the protein conformations, starting from the initial location ascertained from the mGST-1 structure. Possible binding site for the substrate, prostaglandin H2 (PGH2), was identified by systematically probing the refined molecular structure of mPGES-1. A binding model was generated by induced fit docking of PGH2 in the presence of GSH. The homology model prescribes three potential inhibitor binding sites per mPGES-1 trimer. This was further confirmed experimentally by equilibrium dialysis study which generated a binding stoichiometric ratio of approximately three inhibitor molecules to three mPGES-1 monomers. The structural model that we have derived could serve as a useful tool for structure-guided design of inhibitors for this emergently important therapeutic target.

  6. Data-driven model comparing the effects of glial scarring and interface interactions on chronic neural recordings in non-human primates

    NASA Astrophysics Data System (ADS)

    Malaga, Karlo A.; Schroeder, Karen E.; Patel, Paras R.; Irwin, Zachary T.; Thompson, David E.; Bentley, J. Nicole; Lempka, Scott F.; Chestek, Cynthia A.; Patil, Parag G.

    2016-02-01

    Objective. We characterized electrode stability over twelve weeks of impedance and neural recording data from four chronically-implanted Utah arrays in two rhesus macaques, and investigated the effects of glial scarring and interface interactions at the electrode recording site on signal quality using a computational model. Approach. A finite-element model of a Utah array microelectrode in neural tissue was coupled with a multi-compartmental model of a neuron to quantify the effects of encapsulation thickness, encapsulation resistivity, and interface resistivity on electrode impedance and waveform amplitude. The coupled model was then reconciled with the in vivo data. Histology was obtained seventeen weeks post-implantation to measure gliosis. Main results. From week 1-3, mean impedance and amplitude increased at rates of 115.8 kΩ/week and 23.1 μV/week, respectively. This initial ramp up in impedance and amplitude was observed across all arrays, and is consistent with biofouling (increasing interface resistivity) and edema clearing (increasing tissue resistivity), respectively, in the model. Beyond week 3, the trends leveled out. Histology showed that thin scars formed around the electrodes. In the model, scarring could not match the in vivo data. However, a thin interface layer at the electrode tip could. Despite having a large effect on impedance, interface resistivity did not have a noticeable effect on amplitude. Significance. This study suggests that scarring does not cause an electrical problem with regard to signal quality since it does not appear to be the main contributor to increasing impedance or significantly affect amplitude unless it displaces neurons. This, in turn, suggests that neural signals can be obtained reliably despite scarring as long as the recording site has sufficiently low impedance after accumulating a thin layer of biofouling. Therefore, advancements in microelectrode technology may be expedited by focusing on improvements to the

  7. Perspectives on human performance modelling

    SciTech Connect

    Pew, R.W.; Baron, S.

    1983-11-01

    A combination of psychologically-based and control-theoretic approaches to human performance modelling results in other models which have the potential for unifying related works in psychology, artificial intelligence, and system-oriented supervisory control. 33 references.

  8. Stochastic Models of Human Errors

    NASA Technical Reports Server (NTRS)

    Elshamy, Maged; Elliott, Dawn M. (Technical Monitor)

    2002-01-01

    Humans play an important role in the overall reliability of engineering systems. More often accidents and systems failure are traced to human errors. Therefore, in order to have meaningful system risk analysis, the reliability of the human element must be taken into consideration. Describing the human error process by mathematical models is a key to analyzing contributing factors. Therefore, the objective of this research effort is to establish stochastic models substantiated by sound theoretic foundation to address the occurrence of human errors in the processing of the space shuttle.

  9. An Interaction-Centric Learning Model.

    ERIC Educational Resources Information Center

    Ohl, Todd Michael

    2001-01-01

    Considers whether current definitions of interactivity in educational software are optimal and suggests a new model of interaction based on how learners interact mentally with new schema and on educational psychology. Discusses knowledge acquisition; production, or the creation of new knowledge; collaboration; and applying the learning interaction…

  10. Norovirus-host interaction: multi-selections by human HBGAs

    PubMed Central

    Tan, Ming; Jiang, Xi

    2011-01-01

    The discovery of human histo-blood group antigens (HBGAs) as receptors or ligands of noroviruses (NoVs) raises a question about the potential role of host factors in the evolution and diversity of NoVs. Recent structural analysis of selected strains in the two major genogroups of human NoVs (GI and GII) demonstrated highly conserved HBGA binding interfaces within the two groups but not between them, indicating convergent evolution of GI and GII NoVs. GI and GII NoVs are likely introduced to humans from different non-human hosts with the HBGAs as a common niche. Each genogroup has further diverged into multiple sub-lineages (genotypes) through selections by the polymorphic HBGAs of the hosts. An elucidation of such pathogen-host interaction, including determination of the phenotypes of NoV-HBGAs interaction for each genotype, is important in understanding the epidemiology, classification and disease control and prevention of NoVs. A model of this multi-selection of NoVs by HBGAs is proposed. PMID:21705222

  11. Conversation as a Model of Instructional Interaction

    ERIC Educational Resources Information Center

    Van Bramer, Joan

    2003-01-01

    The role of social context and the nature of human interaction provide rich resources for the study of learning and human cognition. In order to understand these elements more fully, it is important to consider the language in use within these contexts. The early intervention Reading Recovery is grounded in the belief that the conversation between…

  12. Integrated Environmental Modelling: human decisions, human challenges

    USGS Publications Warehouse

    Glynn, Pierre D.

    2015-01-01

    Integrated Environmental Modelling (IEM) is an invaluable tool for understanding the complex, dynamic ecosystems that house our natural resources and control our environments. Human behaviour affects the ways in which the science of IEM is assembled and used for meaningful societal applications. In particular, human biases and heuristics reflect adaptation and experiential learning to issues with frequent, sharply distinguished, feedbacks. Unfortunately, human behaviour is not adapted to the more diffusely experienced problems that IEM typically seeks to address. Twelve biases are identified that affect IEM (and science in general). These biases are supported by personal observations and by the findings of behavioural scientists. A process for critical analysis is proposed that addresses some human challenges of IEM and solicits explicit description of (1) represented processes and information, (2) unrepresented processes and information, and (3) accounting for, and cognizance of, potential human biases. Several other suggestions are also made that generally complement maintaining attitudes of watchful humility, open-mindedness, honesty and transparent accountability. These suggestions include (1) creating a new area of study in the behavioural biogeosciences, (2) using structured processes for engaging the modelling and stakeholder communities in IEM, and (3) using ‘red teams’ to increase resilience of IEM constructs and use.

  13. The Application of Humanized Mouse Models for the Study of Human Exclusive Viruses.

    PubMed

    Vahedi, Fatemeh; Giles, Elizabeth C; Ashkar, Ali A

    2017-01-01

    The symbiosis between humans and viruses has allowed human tropic pathogens to evolve intricate means of modulating the human immune response to ensure its survival among the human population. In doing so, these viruses have developed profound mechanisms that mesh closely with our human biology. The establishment of this intimate relationship has created a species-specific barrier to infection, restricting the virus-associated pathologies to humans. This specificity diminishes the utility of traditional animal models. Humanized mice offer a model unique to all other means of study, providing an in vivo platform for the careful examination of human tropic viruses and their interaction with human cells and tissues. These types of animal models have provided a reliable medium for the study of human-virus interactions, a relationship that could otherwise not be investigated without questionable relevance to humans.

  14. The importance of accurately modelling human interactions. Comment on "Coupled disease-behavior dynamics on complex networks: A review" by Z. Wang et al.

    NASA Astrophysics Data System (ADS)

    Rosati, Dora P.; Molina, Chai; Earn, David J. D.

    2015-12-01

    Human behaviour and disease dynamics can greatly influence each other. In particular, people often engage in self-protective behaviours that affect epidemic patterns (e.g., vaccination, use of barrier precautions, isolation, etc.). Self-protective measures usually have a mitigating effect on an epidemic [16], but can in principle have negative impacts at the population level [12,15,18]. The structure of underlying social and biological contact networks can significantly influence the specific ways in which population-level effects are manifested. Using a different contact network in a disease dynamics model-keeping all else equal-can yield very different epidemic patterns. For example, it has been shown that when individuals imitate their neighbours' vaccination decisions with some probability, this can lead to herd immunity in some networks [9], yet for other networks it can preserve clusters of susceptible individuals that can drive further outbreaks of infectious disease [12].

  15. Synchronization in human musical rhythms and mutually interacting complex systems

    PubMed Central

    Hennig, Holger

    2014-01-01

    Though the music produced by an ensemble is influenced by multiple factors, including musical genre, musician skill, and individual interpretation, rhythmic synchronization is at the foundation of musical interaction. Here, we study the statistical nature of the mutual interaction between two humans synchronizing rhythms. We find that the interbeat intervals of both laypeople and professional musicians exhibit scale-free (power law) cross-correlations. Surprisingly, the next beat to be played by one person is dependent on the entire history of the other person’s interbeat intervals on timescales up to several minutes. To understand this finding, we propose a general stochastic model for mutually interacting complex systems, which suggests a physiologically motivated explanation for the occurrence of scale-free cross-correlations. We show that the observed long-term memory phenomenon in rhythmic synchronization can be imitated by fractal coupling of separately recorded or synthesized audio tracks and thus applied in electronic music. Though this study provides an understanding of fundamental characteristics of timing and synchronization at the interbrain level, the mutually interacting complex systems model may also be applied to study the dynamics of other complex systems where scale-free cross-correlations have been observed, including econophysics, physiological time series, and collective behavior of animal flocks. PMID:25114228

  16. Synchronization in human musical rhythms and mutually interacting complex systems.

    PubMed

    Hennig, Holger

    2014-09-09

    Though the music produced by an ensemble is influenced by multiple factors, including musical genre, musician skill, and individual interpretation, rhythmic synchronization is at the foundation of musical interaction. Here, we study the statistical nature of the mutual interaction between two humans synchronizing rhythms. We find that the interbeat intervals of both laypeople and professional musicians exhibit scale-free (power law) cross-correlations. Surprisingly, the next beat to be played by one person is dependent on the entire history of the other person's interbeat intervals on timescales up to several minutes. To understand this finding, we propose a general stochastic model for mutually interacting complex systems, which suggests a physiologically motivated explanation for the occurrence of scale-free cross-correlations. We show that the observed long-term memory phenomenon in rhythmic synchronization can be imitated by fractal coupling of separately recorded or synthesized audio tracks and thus applied in electronic music. Though this study provides an understanding of fundamental characteristics of timing and synchronization at the interbrain level, the mutually interacting complex systems model may also be applied to study the dynamics of other complex systems where scale-free cross-correlations have been observed, including econophysics, physiological time series, and collective behavior of animal flocks.

  17. Protein interactions in human genetic diseases

    PubMed Central

    Schuster-Böckler, Benjamin; Bateman, Alex

    2008-01-01

    We present a novel method that combines protein structure information with protein interaction data to identify residues that form part of an interaction interface. Our prediction method can retrieve interaction hotspots with an accuracy of 60% (at a 20% false positive rate). The method was applied to all mutations in the Online Mendelian Inheritance in Man (OMIM) database, predicting 1,428 mutations to be related to an interaction defect. Combining predicted and hand-curated sets, we discuss how mutations affect protein interactions in general. PMID:18199329

  18. Child Characteristics by Model Interactions.

    ERIC Educational Resources Information Center

    Featherstone, Helen J.

    Data from the 1969-70 and 1970-71 Head Start Planned Variation (HSPV)Study were used to examine program-child interactions. An effort was made to determine whether different preschool programs have different cognitive effects on different types of children. Seven hypotheses for the analysis of the data were generated from the results of the HSPV…

  19. Human lung ex vivo infection models.

    PubMed

    Hocke, Andreas C; Suttorp, Norbert; Hippenstiel, Stefan

    2017-03-01

    Pneumonia is counted among the leading causes of death worldwide. Viruses, bacteria and pathogen-related molecules interact with cells present in the human alveolus by numerous, yet poorly understood ways. Traditional cell culture models little reflect the cellular composition, matrix complexity and three-dimensional architecture of the human lung. Integrative animal models suffer from species differences, which are of particular importance for the investigation of zoonotic lung diseases. The use of cultured ex vivo infected human lung tissue may overcome some of these limitations and complement traditional models. The present review gives an overview of common bacterial lung infections, such as pneumococcal infection and of widely neglected pathogens modeled in ex vivo infected lung tissue. The role of ex vivo infected lung tissue for the investigation of emerging viral zoonosis including influenza A virus and Middle East respiratory syndrome coronavirus is discussed. Finally, further directions for the elaboration of such models are revealed. Overall, the introduced models represent meaningful and robust methods to investigate principles of pathogen-host interaction in original human lung tissue.

  20. Animal models of human response to dioxins.

    PubMed Central

    Grassman, J A; Masten, S A; Walker, N J; Lucier, G W

    1998-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent member of a class of chlorinated hydrocarbons that interact with the aryl hydrocarbon receptor (AhR). TCDD and dioxinlike compounds are environmentally and biologically stable and as a result, human exposure is chronic and widespread. Studies of highly exposed human populations show that dioxins produce developmental effects, chloracne, and an increase in all cancers and suggest that they may also alter immune and endocrine function. In contrast, the health effects of low-level environmental exposure have not been established. Experimental animal models can enhance the understanding of the effects of low-level dioxin exposure, particularly when there is evidence that humans respond similarly to the animal models. Although there are species differences in pharmacokinetics, experimental animal models demonstrate AhR-dependent health effects that are similar to those found in exposed human populations. Comparisons of biochemical changes show that humans and animal models have similar degrees of sensitivity to dioxin-induced effects. The information gained from animal models is important for developing mechanistic models of dioxin toxicity and critical for assessing the risks to human populations under different circumstances of exposure. PMID:9599728

  1. Detecting abandoned objects using interacting multiple models

    NASA Astrophysics Data System (ADS)

    Becker, Stefan; Münch, David; Kieritz, Hilke; Hübner, Wolfgang; Arens, Michael

    2015-10-01

    In recent years, the wide use of video surveillance systems has caused an enormous increase in the amount of data that has to be stored, monitored, and processed. As a consequence, it is crucial to support human operators with automated surveillance applications. Towards this end an intelligent video analysis module for real-time alerting in case of abandoned objects in public spaces is proposed. The overall processing pipeline consists of two major parts. First, person motion is modeled using an Interacting Multiple Model (IMM) filter. The IMM filter estimates the state of a person according to a finite-state, discrete-time Markov chain. Second, the location of persons that stay at a fixed position defines a region of interest, in which a nonparametric background model with dynamic per-pixel state variables identifies abandoned objects. In case of a detected abandoned object, an alarm event is triggered. The effectiveness of the proposed system is evaluated on the PETS 2006 dataset and the i-Lids dataset, both reflecting prototypical surveillance scenarios.

  2. Perceptual-Motor Control in Human-Computer Interaction.

    DTIC Science & Technology

    1996-03-01

    This report isolates and examines some of the emergent perceptual-motor issues raised by the new style in human - computer interaction . It concerns...be studied. I also cover research from both the motor-control and the human - computer interaction literature that applies to perceptual and motor aspects of menu selection.

  3. Questioning Mechanisms During Tutoring, Conversation, and Human-Computer Interaction

    DTIC Science & Technology

    1992-10-14

    grant awarded to Arthur C. Graesser, entitled "Questioning Mechanisms during Tutoring, Conversation, and Human - Computer Interaction " (N00014-92-J-1826...Memphis State University QUESTIONING MECHANISMS DURING TUTORING, CONVERSATION, AND HUMAN - COMPUTER INTERACTION Papers in refereed iournals: Graesser, A. C

  4. The Support Model for Interactive Assessment

    ERIC Educational Resources Information Center

    Ahmed, Ayesha; Pollitt, Alastair

    2010-01-01

    The two most common models for assessment involve measuring "how well" students perform on a task (the "quality model"), and "how difficult" a task students can succeed on (the "difficulty model"). By exploiting the interactive potential of computers we may be able to use a third model: measuring "how…

  5. Space Station crew safety - Human factors model

    NASA Technical Reports Server (NTRS)

    Cohen, M. M.; Junge, M. K.

    1984-01-01

    A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this Space Station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.

  6. Space Station crew safety - Human factors model

    NASA Technical Reports Server (NTRS)

    Cohen, M. M.; Junge, M. K.

    1984-01-01

    A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this Space Station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.

  7. Human-Interaction Challenges in UAV-Based Autonomous Surveillance

    NASA Technical Reports Server (NTRS)

    Freed, Michael; Harris, Robert; Shafto, Michael G.

    2004-01-01

    Autonomous UAVs provide a platform for intelligent surveillance in application domains ranging from security and military operations to scientific information gathering and land management. Surveillance tasks are often long duration, requiring that any approach be adaptive to changes in the environment or user needs. We describe a decision- theoretic model of surveillance, appropriate for use on our autonomous helicopter, that provides a basis for optimizing the value of information returned by the UAV. From this approach arise a range of challenges in making this framework practical for use by human operators lacking specialized knowledge of autonomy and mathematics. This paper describes our platform and approach, then describes human-interaction challenges arising from this approach that we have identified and begun to address.

  8. Resolving pathways of interaction of mipafox and a sarin analog with human acetylcholinesterase by kinetics, mass spectrometry and molecular modeling approaches.

    PubMed

    Mangas, I; Taylor, P; Vilanova, E; Estévez, J; França, T C C; Komives, E; Radić, Z

    2016-03-01

    The hydroxyl oxygen of the catalytic triad serine in the active center of serine hydrolase acetylcholinesterase (AChE) attacks organophosphorus compounds (OPs) at the phosphorus atom to displace the primary leaving group and to form a covalent bond. Inhibited AChE can be reactivated by cleavage of the Ser-phosphorus bond either spontaneously or through a reaction with nucleophilic agents, such as oximes. At the same time, the inhibited AChE adduct can lose part of the molecule by progressive dealkylation over time in a process called aging. Reactivation of the aged enzyme has not yet been demonstrated. Here, our goal was to study oxime reactivation and aging reactions of human AChE inhibited by mipafox or a sarin analog (Flu-MPs, fluorescent methylphosphonate). Progressive reactivation was observed after Flu-MPs inhibition using oxime 2-PAM. However, no reactivation was observed after mipafox inhibition with 2-PAM or the more potent oximes used. A peptide fingerprinted mass spectrometry (MS) method, which clearly distinguished the peptide with the active serine (active center peptide, ACP) of the human AChE adducted with OPs, was developed by MALDI-TOF and MALDI-TOF/TOF. The ACP was detected with a diethyl-phosphorylated adduct after paraoxon inhibition, and with an isopropylmethyl-phosphonylated and a methyl-phosphonylated adduct after Flu-MPs inhibition and subsequent aging. Nevertheless, nonaged nonreactivated complexes were seen after mipafox inhibition and incubation with oximes, where MS data showed an ACP with an NN diisopropyl phosphoryl adduct. The kinetic experiments showed no reactivation of activity. The computational molecular model analysis of the mipafox-inhibited hAChE plots of energy versus distance between the atoms separated by dealkylation showed a high energy demand, thus little aging probability. However, with Flu-MPs and DFP, where aging was observed in our MS data and in previously published crystal structures, the energy demand calculated

  9. Resolving pathways of interaction of mipafox and a sarin-analog with human acetylcholinesterase by kinetics, mass spectrometry and molecular modeling approaches

    PubMed Central

    Mangas, I; Taylor, P; Vilanova, E; Estévez, J; Franca, T; Radić, Z

    2016-01-01

    The hydroxyl oxygen of the catalytic triad serine in the active center of serine hydrolase acetylcholinesterase (AChE) attacks organophosphorus compounds (OPs) at the phosphorus atom to displace the primary leaving group and to form a covalent bond. Inhibited AChE can be reactivated by cleavage of the Ser-phosphorus bond either spontaneously or through a reaction with nucleophilic agents, such as oximes. At the same time, the inhibited AChE adduct can lose part of the molecule by progressive dealkylation over time in a process called aging. Reactivation of the aged enzyme has not yet been demonstrated. Here our goal was to study oxime reactivation and aging reactions of human AChE inhibited by mipafox or a sarin analog (Flu-MPs, fluorescent methylphosphonate). Progressive reactivation was observed after Flu-MPs inhibition using oxime 2-PAM. However, no reactivation was observed after mipafox inhibition with 2-PAM or the more potent oximes used. A peptide mass fingerprinted mass spectrometry (MS) method, which clearly distinguished the peptide with the active serine (active center peptide, ACP) of the human AChE adducted with OPs, was developed by MALDI-TOF and MALDI-TOF-TOF. The ACP was detected with a diethyl phosphorylated adduct after paraoxon inhibition, and with an isopropylmethyl phosphonylated and a methyl phosphonylated adduct after Flu-MPs inhibition and subsequent aging. Nevertheless, nonaged nonreactivated complexes were seen after mipafox inhibition and incubation with oximes, where MS data showed an ACP with an NN diidopropyl phosphoryl adduct. The kinetic experiments showed no reactivation of activity. The computational molecular model analysis of the mipafox-inhibited hAChE plots of energy versus distance between the atoms separated by dealkylation showed a high energy demand, thus little aging probability. However with Flu-MPs and DFP, where aging was observed in our MS data and in previously published crystal structures, the energy demand

  10. Quantifying effect of intraplaque hemorrhage on critical plaque wall stress in human atherosclerotic plaques using three-dimensional fluid-structure interaction models.

    PubMed

    Huang, Xueying; Yang, Chun; Canton, Gador; Ferguson, Marina; Yuan, Chun; Tang, Dalin

    2012-12-01

    Recent magnetic resonance studies have indicated that intraplaque hemorrhage (IPH) may accelerate plaque progression and play an important role in plaque destabilization. However, the impact of hemorrhage on critical plaque wall stress (CPWS) and strain (CPWSn) has yet to be determined. The objective of this study was to assess the effect of the presence and size of IPH on wall mechanics. The magnetic resonance image (MRI) of one patient with histology-confirmed IPH was used to build eight 3D fluid-structure interaction (FSI) models by altering the dimensions of the existing IPH. As a secondary end point, the combined effect of IPH and fibrous cap thickness (FCT) was assessed. A volume curve fitting method (VCFM) was applied to generate a mesh that would guarantee numerical convergence. Plaque wall stress (PWS), strain (PWSn), and flow shear stress (FSS) were extracted from all nodal points on the lumen surface for analysis. Keeping other conditions unchanged, the presence of intraplaque hemorrhage caused a significant increase (27.5%) in CPWS; reduced FCT caused an increase of 22.6% of CPWS. Similar results were found for CPWSn. Furthermore, combination of IPH presence, reduced FCT, and increased IPH volume caused an 85% and 75% increase in CPWS and CPWSn, respectively. These results show that intraplaque hemorrhage has considerable impact on plaque stress and strain conditions and accurate quantification of IPH could lead to more accurate assessment of plaque vulnerability. Large-scale studies are needed to further validate our findings.

  11. Human Factors Issues for Interaction with Bio-Inspired Swarms

    DTIC Science & Technology

    2012-10-01

    subtle leaders of fish schools. Pheromone trails also suggest a way to support human interaction as has been explored to a limited extent... Human Factors issues for Interaction with Bio-Inspired Swarms Michael Lewis*, Michael Goodrich**, Katia Sycara+, Mark Steinberg++ * School of...Enabling a human to control such bio-inspired systems is a considerable challenge due to the limitations of each individual robot and the sheer

  12. Analyzing models for interactions of aptamers to proteins

    NASA Astrophysics Data System (ADS)

    Silva, Dilson; Missailidis, Sotiris

    2014-10-01

    We have devised an experimental and theoretical model, based on fluorescent spectroscopy and molecular modelling, to describe the interaction of aptamer (selected against various protein targets) with proteins and albumins in particular. This model, described in this work, has allowed us to decipher the nature of the interactions between aptamers and albumins, the binding site of the aptamers to albumins, the potential role of primer binding to the albumin and expand to the ability of albumin to carry aptamers in the bloodstream, providing data to better understand the level of free aptamer for target binding. We are presenting the study of a variety of aptamers, including those against the MUC1 tumour marker, heparanase and human kallikrein 6 with bovine and human serum albumins and the effect these interactions may have on the bioavailability of the aptamer for target-specific binding and therapeutic activity.

  13. Interaction of perfluorooctanoic acid with human serum albumin

    PubMed Central

    Wu, Ling-Ling; Gao, Hong-Wen; Gao, Nai-Yun; Chen, Fang-Fang; Chen, Ling

    2009-01-01

    Background Recently, perfluorooctanoic acid (PFOA) has become a significant issue in many aspects of environmental ecology, toxicology, pathology and life sciences because it may have serious effects on the endocrine, immune and nervous systems and can lead to embryonic deformities and other diseases. Human serum albumin (HSA) is the major protein component of blood plasma and is called a multifunctional plasma carrier protein because of its ability to bind an unusually broad spectrum of ligands. Results The interaction of PFOA with HSA was investigated in the normal physiological condition by equilibrium dialysis, fluorospectrometry, isothermal titration calorimetry (ITC) and circular dichroism (CD). The non-covalent interaction is resulted from hydrogen bond, van der Waals force and hydrophobic stack. PFOA binding to HSA accorded with two-step binding model with the saturation binding numbers of PFOA, only 1 in the hydrophobic intracavity of HSA and 12 on the exposed outer surface. The interaction of PFOA with HSA is spontaneous and results in change of HSA conformation. The possible binding sites were speculated. Conclusion The present work suggested a characterization method for the intermolecular weak interaction. It is potentially useful for elucidating the toxigenicity of perfluorochemicals when combined with biomolecular function effect, transmembrane transport, toxicological testing and the other experiments. PMID:19442292

  14. Multimodal signature modeling of humans

    NASA Astrophysics Data System (ADS)

    Cathcart, J. Michael; Kocher, Brian; Prussing, Keith; Lane, Sarah; Thomas, Alan

    2010-04-01

    Georgia Tech been investigating method for the detection of covert personnel in traditionally difficult environments (e.g., urban, caves). This program focuses on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. Both aspects are needed to support the development of personnel detection and tracking algorithms. The difficult nature of these personnel-related problems dictates a multimodal sensing approach. Human signature data of sufficient and accurate quality and quantity do not exist, thus the development of an accurate signature model for a human is needed. This model should also simulate various human activities to allow motion-based observables to be exploited. This paper will describe a multimodal signature modeling approach that incorporates human physiological aspects, thermoregulation, and dynamics into the signature calculation. This approach permits both passive and active signatures to be modeled. The focus of the current effort involved the computation of signatures in urban environments. This paper will discuss the development of a human motion model for use in simulating both electro-optical signatures and radar-based signatures. Video sequences of humans in a simulated urban environment will also be presented; results using these sequences for personnel tracking will be presented.

  15. Hypothermia-induced platelet aggregation in human blood in an in vitro model: the dominant role of blood-material interactions.

    PubMed

    Hall, Matthew W; Solen, Kenneth A

    2002-03-05

    Hypothermia-induced platelet aggregation (HIPA) with or without neutrophil involvement may cause neurologic dysfunction during hypothermic surgery. We report the use of a previously developed model to study the contributions of several surfaces, surface area, shear rate, and blood-material exposure time to HIPA. Heparinized (1.5 u/mL) human blood was quenched to 24 degrees C and passed (0.5 mL/min) through a 75-cm long 1/32" ID tubing of polyvinylchloride (PVC), polyethylene (PE), polyurethane (PU), Teflon-FEP, or heparin (Duraflo)-coated PVC. The number of aggregates was measured by a light-scattering method, and the concentration of occlusive aggregates was assessed using constant-pressure filtration (50 mmHg). No differences were seen among PVC, PE, PU, or Teflon-FEP. The heparin-coated PVC tubing produced fewer occlusive aggregates, and heparin leaching from the coating was not the cause of the decrease in occlusive aggregates. Increasing surface area increased the number of aggregates, and increasing shear rates decreased the occlusiveness of those aggregates.

  16. Mouse model for the equilibration interaction between the host immune system and human T-cell leukemia virus type 1 gene expression.

    PubMed

    Furuta, Rika A; Sugiura, Kikuya; Kawakita, Shigenari; Inada, Takefumi; Ikehara, Susumu; Matsuda, Tadashi; Fujisawa, Jun-ichi

    2002-03-01

    To study the involvement of immune responses against Tax of human T-cell leukemia virus type 1 (HTLV-1) in the growth of and gene suppression in Tax-expressing tumor cells in vivo, we established a model system involving C57BL/6J mice and a syngeneic lymphoma cell line, EL4. When mice were immunized by DNA-based immunization with Tax expression plasmids, solid tumor formation upon subcutaneous inoculation of EL4 cells expressing green fluorescent protein-fused Tax (Gax) under the control of the HTLV-1 enhancer was strongly inhibited, and in vitro analysis showed that DNA immunization elicited cytotoxic T-lymphocyte (CTL) responses but not production of antibodies to Tax protein. Since EL4/Gax cells inoculated into DNA-immunized mice were not completely eradicated but were maintained as small solid tumors for a long period, there appeared to be a certain equilibrium between CTL activity and the growth of Gax-expressing cells. With such a balance, expression of the Gax gene in EL4/Gax cells was strongly suppressed. These results suggested that gene expression under the control of the HTLV-1 long terminal repeat and Tax is silenced in vivo, resulting in an equilibrium between viral expression and the host immune system. Such a balance would represent a status of persistent infection by HTLV-1 in virus-infected individuals during the latency period.

  17. Eyeblink Synchrony in Multimodal Human-Android Interaction.

    PubMed

    Tatsukawa, Kyohei; Nakano, Tamami; Ishiguro, Hiroshi; Yoshikawa, Yuichiro

    2016-12-23

    As the result of recent progress in technology of communication robot, robots are becoming an important social partner for humans. Behavioral synchrony is understood as an important factor in establishing good human-robot relationships. In this study, we hypothesized that biasing a human's attitude toward a robot changes the degree of synchrony between human and robot. We first examined whether eyeblinks were synchronized between a human and an android in face-to-face interaction and found that human listeners' eyeblinks were entrained to android speakers' eyeblinks. This eyeblink synchrony disappeared when the android speaker spoke while looking away from the human listeners but was enhanced when the human participants listened to the speaking android while touching the android's hand. These results suggest that eyeblink synchrony reflects a qualitative state in human-robot interactions.

  18. The Monash University Interactive Simple Climate Model

    NASA Astrophysics Data System (ADS)

    Dommenget, D.

    2013-12-01

    The Monash university interactive simple climate model is a web-based interface that allows students and the general public to explore the physical simulation of the climate system with a real global climate model. It is based on the Globally Resolved Energy Balance (GREB) model, which is a climate model published by Dommenget and Floeter [2011] in the international peer review science journal Climate Dynamics. The model simulates most of the main physical processes in the climate system in a very simplistic way and therefore allows very fast and simple climate model simulations on a normal PC computer. Despite its simplicity the model simulates the climate response to external forcings, such as doubling of the CO2 concentrations very realistically (similar to state of the art climate models). The Monash simple climate model web-interface allows you to study the results of more than a 2000 different model experiments in an interactive way and it allows you to study a number of tutorials on the interactions of physical processes in the climate system and solve some puzzles. By switching OFF/ON physical processes you can deconstruct the climate and learn how all the different processes interact to generate the observed climate and how the processes interact to generate the IPCC predicted climate change for anthropogenic CO2 increase. The presentation will illustrate how this web-base tool works and what are the possibilities in teaching students with this tool are.

  19. The Monash University Interactive Simple Climate Model

    NASA Astrophysics Data System (ADS)

    Dommenget, Dietmar

    2013-04-01

    The Monash university interactive simple climate model is a web-based interface that allows students and the general public to explore the physical simulation of the climate system with a real global climate model. It is based on the Globally Resolved Energy Balance (GREB) model, which is a climate model published by Dommenget and Floeter [2011] in the international peer review science journal Climate Dynamics. The model simulates most of the main physical processes in the climate system in a very simplistic way and therefore allows very fast and simple climate model simulations on a normal PC computer. Despite its simplicity the model simulates the climate response to external forcings, such as doubling of the CO2 concentrations very realistically (similar to state of the art climate models). The Monash simple climate model web-interface allows you to study the results of more than a 1000 different model experiments in an interactive way and it allows you to study a number of tutorials on the interactions of physical processes in the climate system. By switching OFF/ON physical processes you can deconstruct the climate and learn how all the different processes interact to generate the observed climate and how the processes interact to generate the IPCC predicted climate change for anthropogenic CO2 increase. The presentation will illustrate how this web-base tool works and what are the possibilities in teaching students with this tool are.

  20. SABRINA - an interactive geometry modeler for MCNP

    SciTech Connect

    West, J.T.; Murphy, J. )

    1988-01-01

    One of the most difficult tasks when analyzing a complex three-dimensional system with Monte Carlo is geometry model development. SABRINA attempts to make the modeling process more user-friendly and less of an obstacle. It accepts both combinatorial solid bodies and MCNP surfaces and produces MCNP cells. The model development process in SABRINA is highly interactive and gives the user immediate feedback on errors. Users can view their geometry from arbitrary perspectives while the model is under development and interactively find and correct modeling errors. An example of a SABRINA display is shown. It represents a complex three-dimensional shape.

  1. The effect of model uncertainty on cooperation in sensorimotor interactions

    PubMed Central

    Grau-Moya, J.; Hez, E.; Pezzulo, G.; Braun, D. A.

    2013-01-01

    Decision-makers have been shown to rely on probabilistic models for perception and action. However, these models can be incorrect or partially wrong in which case the decision-maker has to cope with model uncertainty. Model uncertainty has recently also been shown to be an important determinant of sensorimotor behaviour in humans that can lead to risk-sensitive deviations from Bayes optimal behaviour towards worst-case or best-case outcomes. Here, we investigate the effect of model uncertainty on cooperation in sensorimotor interactions similar to the stag-hunt game, where players develop models about the other player and decide between a pay-off-dominant cooperative solution and a risk-dominant, non-cooperative solution. In simulations, we show that players who allow for optimistic deviations from their opponent model are much more likely to converge to cooperative outcomes. We also implemented this agent model in a virtual reality environment, and let human subjects play against a virtual player. In this game, subjects' pay-offs were experienced as forces opposing their movements. During the experiment, we manipulated the risk sensitivity of the computer player and observed human responses. We found not only that humans adaptively changed their level of cooperation depending on the risk sensitivity of the computer player but also that their initial play exhibited characteristic risk-sensitive biases. Our results suggest that model uncertainty is an important determinant of cooperation in two-player sensorimotor interactions. PMID:23945266

  2. Human driven transitions in complex model ecosystems

    NASA Astrophysics Data System (ADS)

    Harfoot, Mike; Newbold, Tim; Tittinsor, Derek; Purves, Drew

    2015-04-01

    Human activities have been observed to be impacting ecosystems across the globe, leading to reduced ecosystem functioning, altered trophic and biomass structure and ultimately ecosystem collapse. Previous attempts to understand global human impacts on ecosystems have usually relied on statistical models, which do not explicitly model the processes underlying the functioning of ecosystems, represent only a small proportion of organisms and do not adequately capture complex non-linear and dynamic responses of ecosystems to perturbations. We use a mechanistic ecosystem model (1), which simulates the underlying processes structuring ecosystems and can thus capture complex and dynamic interactions, to investigate boundaries of complex ecosystems to human perturbation. We explore several drivers including human appropriation of net primary production and harvesting of animal biomass. We also present an analysis of the key interactions between biotic, societal and abiotic earth system components, considering why and how we might think about these couplings. References: M. B. J. Harfoot et al., Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model., PLoS Biol. 12, e1001841 (2014).

  3. Acute experimental changes in mood state regulate immune function in relation to central opioid neurotransmission: a model of human CNS-peripheral inflammatory interaction.

    PubMed

    Prossin, A R; Koch, A E; Campbell, P L; Barichello, T; Zalcman, S S; Zubieta, J-K

    2016-02-01

    Although evidence shows depressed moods enhance risk for somatic diseases, molecular mechanisms underlying enhanced somatic susceptibility are ill-defined. Knowledge of these molecular mechanisms will inform development of treatment and prevention strategies across comorbid depressive and somatic illnesses. Existing evidence suggests that interleukin-18 (IL-18; an IL-1 family cytokine) is elevated in depression and implicated in pathophysiology underlying comorbid medical illnesses. We previously identified strong associations between baseline IL-18 and μ-opioid receptor availability in major depressive disorder (MDD) volunteers. Combined with the evidence in animal models, we hypothesized that experimental mood induction would change IL-18, the extent proportional to opioid neurotransmitter release. Using the Velten technique in a [(11)C]carfentanil positron emission tomography neuroimaging study, we examined the impact of experimentally induced mood (sad, neutral) on plasma IL-18 and relationships with concurrent changes in the central opioid neurotransmission in 28 volunteers (healthy, MDD). Results showed mood induction impacted IL-18 (F2,25=12.2, P<0.001), sadness increasing IL-18 (T27=2.6, P=0.01) and neutral mood reducing IL-18 (T27=-4.1, P<0.001). In depressed volunteers, changes in IL-18 were more pronounced (F2,25=3.6, P=0.03) and linearly proportional to sadness-induced μ-opioid activation (left ventral pallidum, bilateral anterior cingulate cortices, right hypothalamus and bilateral amygdala). These data demonstrate that dynamic changes of a pro-inflammatory IL-1 superfamily cytokine, IL-18, and its relationship to μ-opioid neurotransmission in response to experimentally induced sadness. Further testing is warranted to delineate the role of neuroimmune interactions involving IL-18 in enhancing susceptibility to medical illness (that is, diabetes, heart disease and persistent pain states) in depressed individuals.

  4. Acute experimental changes in mood state regulate immune function in relation to central opioid neurotransmission: a model of human CNS-peripheral inflammatory interaction

    PubMed Central

    Prossin, A R; Koch, A E; Campbell, P L; Barichello, T; Zalcman, S S; Zubieta, J-K

    2016-01-01

    Although evidence shows depressed moods enhance risk for somatic diseases, molecular mechanisms underlying enhanced somatic susceptibility are ill-defined. Knowledge of these molecular mechanisms will inform development of treatment and prevention strategies across comorbid depressive and somatic illnesses. Existing evidence suggests that interleukin-18 (IL-18; an IL-1 family cytokine) is elevated in depression and implicated in pathophysiology underlying comorbid medical illnesses. We previously identified strong associations between baseline IL-18 and μ-opioid receptor availability in major depressive disorder (MDD) volunteers. Combined with the evidence in animal models, we hypothesized that experimental mood induction would change IL-18, the extent proportional to opioid neurotransmitter release. Using the Velten technique in a [11C]carfentanil positron emission tomography neuroimaging study, we examined the impact of experimentally induced mood (sad, neutral) on plasma IL-18 and relationships with concurrent changes in the central opioid neurotransmission in 28 volunteers (healthy, MDD). Results showed mood induction impacted IL-18 (F2,25=12.2, P<0.001), sadness increasing IL-18 (T27=2.6, P=0.01) and neutral mood reducing IL-18 (T27=−4.1, P<0.001). In depressed volunteers, changes in IL-18 were more pronounced (F2,25=3.6, P=0.03) and linearly proportional to sadness-induced μ-opioid activation (left ventral pallidum, bilateral anterior cingulate cortices, right hypothalamus and bilateral amygdala). These data demonstrate that dynamic changes of a pro-inflammatory IL-1 superfamily cytokine, IL-18, and its relationship to μ-opioid neurotransmission in response to experimentally induced sadness. Further testing is warranted to delineate the role of neuroimmune interactions involving IL-18 in enhancing susceptibility to medical illness (that is, diabetes, heart disease and persistent pain states) in depressed individuals. PMID:26283642

  5. Functionalized Anatomical Models for EM-Neuron Interaction Modeling

    PubMed Central

    Neufeld, Esra; Cassará, Antonino Mario; Montanaro, Hazael; Kuster, Niels; Kainz, Wolfgang

    2017-01-01

    The understanding of interactions between electromagnetic (EM) fields and nerves are crucial in contexts ranging from therapeutic neurostimulation to low frequency EM exposure safety. To properly consider the impact of in-vivo induced field inhomogeneity on non-linear neuronal dynamics, coupled EM-neuronal dynamics modeling is required. For that purpose, novel functionalized computable human phantoms have been developed. Their implementation and the systematic verification of the integrated anisotropic quasi-static EM solver and neuronal dynamics modeling functionality, based on the method of manufactured solutions and numerical reference data, is described. Electric and magnetic stimulation of the ulnar and sciatic nerve were modeled to help understanding a range of controversial issues related to the magnitude and optimal determination of strength-duration (SD) time constants. The results indicate the importance of considering the stimulation-specific inhomogeneous field distributions (especially at tissue interfaces), realistic models of non-linear neuronal dynamics, very short pulses, and suitable SD extrapolation models. These results and the functionalized computable phantom will influence and support the development of safe and effective neuroprosthetic devices and novel electroceuticals. Furthermore they will assist the evaluation of existing low frequency exposure standards for the entire population under all exposure conditions. PMID:27224508

  6. Functionalized anatomical models for EM-neuron Interaction modeling

    NASA Astrophysics Data System (ADS)

    Neufeld, Esra; Cassará, Antonino Mario; Montanaro, Hazael; Kuster, Niels; Kainz, Wolfgang

    2016-06-01

    The understanding of interactions between electromagnetic (EM) fields and nerves are crucial in contexts ranging from therapeutic neurostimulation to low frequency EM exposure safety. To properly consider the impact of in vivo induced field inhomogeneity on non-linear neuronal dynamics, coupled EM-neuronal dynamics modeling is required. For that purpose, novel functionalized computable human phantoms have been developed. Their implementation and the systematic verification of the integrated anisotropic quasi-static EM solver and neuronal dynamics modeling functionality, based on the method of manufactured solutions and numerical reference data, is described. Electric and magnetic stimulation of the ulnar and sciatic nerve were modeled to help understanding a range of controversial issues related to the magnitude and optimal determination of strength-duration (SD) time constants. The results indicate the importance of considering the stimulation-specific inhomogeneous field distributions (especially at tissue interfaces), realistic models of non-linear neuronal dynamics, very short pulses, and suitable SD extrapolation models. These results and the functionalized computable phantom will influence and support the development of safe and effective neuroprosthetic devices and novel electroceuticals. Furthermore they will assist the evaluation of existing low frequency exposure standards for the entire population under all exposure conditions.

  7. Human motion analysis and modeling

    NASA Astrophysics Data System (ADS)

    Prussing, Keith; Cathcart, J. Michael; Kocher, Brian

    2011-06-01

    Georgia Tech has investigated methods for the detection and tracking of personnel in a variety of acquisition environments. This research effort focused on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. As a fundamental part of this research effort, Georgia Tech collected motion capture data on an individual for a variety of walking speeds, carrying loads, and load distributions. These data formed the basis for deriving fundamental properties of the individual's motion and supported the development of a physiologically-based human motion model. Subsequently this model aided the derivation and analysis of motion-based observables, particularly changes in the motion of various body components resulting from load variations. This paper will describe the data acquisition process, development of the human motion model, and use of the model in the observable analysis. Video sequences illustrating the motion data and modeling results will also be presented.

  8. Modeling of laser interactions with composite materials

    SciTech Connect

    Rubenchik, Alexander M.; Boley, Charles D.

    2013-05-07

    In this study, we develop models of laser interactions with composite materials consisting of fibers embedded within a matrix. A ray-trace model is shown to determine the absorptivity, absorption depth, and optical power enhancement within the material, as well as the angular distribution of the reflected light. We also develop a macroscopic model, which provides physical insight and overall results. We show that the parameters in this model can be determined from the ray trace model.

  9. Modeling of laser interactions with composite materials

    DOE PAGES

    Rubenchik, Alexander M.; Boley, Charles D.

    2013-05-07

    In this study, we develop models of laser interactions with composite materials consisting of fibers embedded within a matrix. A ray-trace model is shown to determine the absorptivity, absorption depth, and optical power enhancement within the material, as well as the angular distribution of the reflected light. We also develop a macroscopic model, which provides physical insight and overall results. We show that the parameters in this model can be determined from the ray trace model.

  10. Mouse models of human disease

    PubMed Central

    Perlman, Robert L.

    2016-01-01

    The use of mice as model organisms to study human biology is predicated on the genetic and physiological similarities between the species. Nonetheless, mice and humans have evolved in and become adapted to different environments and so, despite their phylogenetic relatedness, they have become very different organisms. Mice often respond to experimental interventions in ways that differ strikingly from humans. Mice are invaluable for studying biological processes that have been conserved during the evolution of the rodent and primate lineages and for investigating the developmental mechanisms by which the conserved mammalian genome gives rise to a variety of different species. Mice are less reliable as models of human disease, however, because the networks linking genes to disease are likely to differ between the two species. The use of mice in biomedical research needs to take account of the evolved differences as well as the similarities between mice and humans. PMID:27121451

  11. Modeling interaction for image-guided procedures

    NASA Astrophysics Data System (ADS)

    Trevisan, Daniela G.; Vanderdonckt, Jean; Macq, Benoit M. M.; Raftopoulos, Christian

    2003-05-01

    Compared to conventional interfaces, image guided surgery (IGS) interfaces contain a richer variety and more complex objects and interaction types. The main interactive characteristics emering from systems like this is the interaction focus shared between physical space, where the surgeon interacts with the patient using surgical tools, and with the digital world, where the surgeon interacts with the system. This limitation results in two different interfaces likely inconsistent, thereby the interaction discontinuities do break the natuarl workflow forcing the user to switch between the operation modes. Our work addresses these features by focusing on the model, interaction and ergonomic integrity analysis considering the Augmented Reality paradigm applied to IGS procedures and more specifically applied to the Neurosurgery study case. We followed a methodology according to the model-based approach, including new extensions in order to support interaction technologies and to sensure continuity interaction according to the IGS system requirements. As a result, designers may as soon as possible discover errors in the development process and may perform an efficient interface design coherently integrating constraints favoring continuity instead of discrete interaction with possible inconsistencies.

  12. Key Results of Interaction Models with Centering

    ERIC Educational Resources Information Center

    Afshartous, David; Preston, Richard A.

    2011-01-01

    We consider the effect on estimation of simultaneous variable centering and interaction effects in linear regression. We technically define, review, and amplify many of the statistical issues for interaction models with centering in order to create a useful and compact reference for teachers, students, and applied researchers. In addition, we…

  13. Lattice gas models with long range interactions

    NASA Astrophysics Data System (ADS)

    Aristoff, David; Zhu, Lingjiong

    2017-02-01

    We study microcanonical lattice gas models with long range interactions, including power law interactions. We rigorously obtain a variational principle for the entropy. In a one dimensional example, we find a first order phase transition by proving the entropy is non-differentiable along a certain curve.

  14. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas - Urban Climate

    EPA Science Inventory

    Human health and well-being are and will be affected by climate change, both directly through changes in extreme weather events and indirectly through weather-induced changes in human and natural systems. Populations are vulnerable to these changes in varying degrees, depending ...

  15. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas - Urban Climate

    EPA Science Inventory

    Human health and well-being are and will be affected by climate change, both directly through changes in extreme weather events and indirectly through weather-induced changes in human and natural systems. Populations are vulnerable to these changes in varying degrees, depending ...

  16. Syndetic model of fundamental interactions

    DOE PAGES

    Ma, Ernest

    2015-02-01

    The standard model of quarks and leptons is extended to connect three outstanding issues in particle physics and astrophysics: (1) the absence of strong CP nonconservation, (2) the existence of dark matter, and (3) the mechanism of nonzero neutrino masses, and that of the first family of quarks and leptons, all in the context of having only one Higgs boson in a renormalizable theory. Some phenomenological implications are discussed.

  17. Eyeblink Synchrony in Multimodal Human-Android Interaction

    PubMed Central

    Tatsukawa, Kyohei; Nakano, Tamami; Ishiguro, Hiroshi; Yoshikawa, Yuichiro

    2016-01-01

    As the result of recent progress in technology of communication robot, robots are becoming an important social partner for humans. Behavioral synchrony is understood as an important factor in establishing good human-robot relationships. In this study, we hypothesized that biasing a human’s attitude toward a robot changes the degree of synchrony between human and robot. We first examined whether eyeblinks were synchronized between a human and an android in face-to-face interaction and found that human listeners’ eyeblinks were entrained to android speakers’ eyeblinks. This eyeblink synchrony disappeared when the android speaker spoke while looking away from the human listeners but was enhanced when the human participants listened to the speaking android while touching the android’s hand. These results suggest that eyeblink synchrony reflects a qualitative state in human-robot interactions. PMID:28009014

  18. Mathematical models for plant-herbivore interactions

    USGS Publications Warehouse

    Feng, Zhilan; DeAngelis, Donald L.

    2017-01-01

    Mathematical Models of Plant-Herbivore Interactions addresses mathematical models in the study of practical questions in ecology, particularly factors that affect herbivory, including plant defense, herbivore natural enemies, and adaptive herbivory, as well as the effects of these on plant community dynamics. The result of extensive research on the use of mathematical modeling to investigate the effects of plant defenses on plant-herbivore dynamics, this book describes a toxin-determined functional response model (TDFRM) that helps explains field observations of these interactions. This book is intended for graduate students and researchers interested in mathematical biology and ecology.

  19. Time scale interactions and the coevolution of humans and water

    NASA Astrophysics Data System (ADS)

    Sivapalan, Murugesu; Blöschl, Günter

    2015-09-01

    We present a coevolutionary view of hydrologic systems, revolving around feedbacks between environmental and social processes operating across different time scales. This brings to the fore an emphasis on emergent phenomena in changing water systems, such as the levee effect, adaptation to change, system lock-in, and system collapse due to resource depletion. Changing human values play a key role in the emergence of these phenomena and should therefore be considered as internal to the system. Guidance is provided for the framing and modeling of these phenomena to test alternative hypotheses about how they arose. A plurality of coevolutionary models, from stylized to comprehensive system-of-system models, may assist strategic water management for long time scales through facilitating stakeholder participation, exploring the possibility space of alternative futures, and helping to synthesize the observed dynamics in a wide range of case studies. Future research opportunities lie in exploring emergent phenomena arising from time scale interactions through historical, comparative, and process studies of human-water feedbacks.

  20. Rodent models for human diseases.

    PubMed

    Vandamme, Thierry F

    2015-07-15

    One of the factors limiting the translation of knowledge from preclinical studies to the clinic has been the limitations of in vivo diseases models. Except in the case of highly controlled and regulated clinical trials, geneticists and scientists do not use humans for their experimental investigations because of the obvious risk to life. Instead, they use various animal, fungal, bacterial, and plant species as model organisms for their studies. Amongst these model organisms, rodent models are the most used due to the easiness for the experiments and the possibility to modify genetically these model animals. Nevertheless, due to the fact that animal models typically do not contract the same genetic diseases as people, so scientists must alter their genomes to induce human disease states and to know what kind of mutation causes the disease. In this brief review, we will discuss the interests of rodent models that have been developed to simulate human pathologies, focusing in models that employ xenografts and genetic modification. Within the framework of genetically engineered mouse (GEM) models, we will review some of the current genetic strategies for modeling diseases.

  1. Interaction of an atypical Plasmodium falciparum ETRAMP with human apolipoproteins

    PubMed Central

    Vignali, Marissa; McKinlay, Anastasia; LaCount, Douglas J; Chettier, Rakesh; Bell, Russell; Sahasrabudhe, Sudhir; Hughes, Robert E; Fields, Stanley

    2008-01-01

    Background In order to establish a successful infection in the human host, the malaria parasite Plasmodium falciparum must establish interactions with a variety of human proteins on the surface of different cell types, as well as with proteins inside the host cells. To better understand this aspect of malaria pathogenesis, a study was conducted with the goal of identifying interactions between proteins of the parasite and those of its human host. Methods A modified yeast two-hybrid methodology that preferentially selects protein fragments that can be expressed in yeast was used to conduct high-throughput screens with P. falciparum protein fragments against human liver and cerebellum libraries. The resulting dataset was analyzed to exclude interactions that are not likely to occur in the human host during infection. Results An initial set of 2,200 interactions was curated to remove proteins that are unlikely to play a role in pathogenesis based on their annotation or localization, and proteins that behave promiscuously in the two-hybrid assay, resulting in a final dataset of 456 interactions. A cluster that implicates binding between P. falciparum PFE1590w/ETRAMP5, a putative parasitophorous vacuole membrane protein, and human apolipoproteins ApoA, ApoB and ApoE was selected for further analysis. Different isoforms of ApoE, which are associated with different outcomes of malaria infection, were shown to display differential interactions with PFE1590w. Conclusion A dataset of interactions between proteins of P. falciparum and those of its human host was generated. The preferential interaction of the P. falciparum PFE1590w protein with the human ApoE ε3 and ApoE ε4 isoforms, but not the ApoE ε2 isoform, supports the hypothesis that ApoE genotype affects risk of malaria infection. The dataset contains other interactions of potential relevance to disease that may identify possible vaccine candidates and drug targets. PMID:18937849

  2. Socially intelligent robots: dimensions of human-robot interaction.

    PubMed

    Dautenhahn, Kerstin

    2007-04-29

    Social intelligence in robots has a quite recent history in artificial intelligence and robotics. However, it has become increasingly apparent that social and interactive skills are necessary requirements in many application areas and contexts where robots need to interact and collaborate with other robots or humans. Research on human-robot interaction (HRI) poses many challenges regarding the nature of interactivity and 'social behaviour' in robot and humans. The first part of this paper addresses dimensions of HRI, discussing requirements on social skills for robots and introducing the conceptual space of HRI studies. In order to illustrate these concepts, two examples of HRI research are presented. First, research is surveyed which investigates the development of a cognitive robot companion. The aim of this work is to develop social rules for robot behaviour (a 'robotiquette') that is comfortable and acceptable to humans. Second, robots are discussed as possible educational or therapeutic toys for children with autism. The concept of interactive emergence in human-child interactions is highlighted. Different types of play among children are discussed in the light of their potential investigation in human-robot experiments. The paper concludes by examining different paradigms regarding 'social relationships' of robots and people interacting with them.

  3. Toxic interactions among environmental pollutants: corroborating laboratory observations with human experience.

    PubMed Central

    Krishnan, K; Brodeur, J

    1994-01-01

    Combined exposures to multiple chemicals may result in interactions leading to a significant increase or decrease in the overall toxicity of the mixture compared to the summation of the toxicity of the components. A large number of chemical interactions have been described in animal studies by administering high doses of chemicals by routes and scenarios often different from anticipated human exposures. Though limited, there is some evidence for the occurrence of several supra-additive (the combined effects are greater than the simple summation of the individual effects) and infra-additive (the combined effects are smaller than the simple summation of the individual effects) chemical interactions in humans. For example, toxicokinetic interactions between several solvents have been found to occur in the workplace, whereas those involving pesticides have been reported less frequently, especially during accidental exposures. Toxic interactions involving nutritionally important metals and metalloids appear to occur more frequently, since several of them have an important role in a variety of physiological and biochemical processes. On the contrary, there is not much evidence to confirm the occurrence of toxic interactions among the commonly encountered inorganic gaseous pollutants in humans. Overall, the majority of chemical interactions observed in animal studies have neither been investigated in humans nor been extrapolated to humans based on appropriate mechanistic considerations. Future research efforts in the chemical interactions arena should address these issues by focusing on the development of mechanistically and biologically based models that allow predictions of the extent of interactions likely to be observed in humans. PMID:7698071

  4. Enhancing Human-Computer Interaction Design Education: Teaching Affordance Design for Emerging Mobile Devices

    ERIC Educational Resources Information Center

    Faiola, Anthony; Matei, Sorin Adam

    2010-01-01

    The evolution of human-computer interaction design (HCID) over the last 20 years suggests that there is a growing need for educational scholars to consider new and more applicable theoretical models of interactive product design. The authors suggest that such paradigms would call for an approach that would equip HCID students with a better…

  5. Enhancing Human-Computer Interaction Design Education: Teaching Affordance Design for Emerging Mobile Devices

    ERIC Educational Resources Information Center

    Faiola, Anthony; Matei, Sorin Adam

    2010-01-01

    The evolution of human-computer interaction design (HCID) over the last 20 years suggests that there is a growing need for educational scholars to consider new and more applicable theoretical models of interactive product design. The authors suggest that such paradigms would call for an approach that would equip HCID students with a better…

  6. Two Invariants of Human-Swarm Interaction

    DTIC Science & Technology

    2017-08-15

    persisitence, fan-out 1. Introduction In the first sentence of his great paper Invariants of Human Behavior, Herbert Simon wrote, “The fundamental goal of...as general nor as ”invariant” as these classical laws” ( Simon , 1990)[page 1]. In other words, science is built on invariants, concepts or properties...direction of travel to the desired heading. In a follow-on paper, we conducted a user study in which we allowed humans to control flocks of Couzin-like

  7. Ergonomics of Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Helander, Martin G.; Palanivel, Thiagarajan

    1992-01-01

    Addresses research results and controversies concerning the ergonomic design of computer work stations ranging from the traditional concerns with anthropometric fashions, work posture, and visual performance to the recent considerations about human information processing capacities and awareness of problem-solving strategies. (eight references)…

  8. Ergonomics of Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Helander, Martin G.; Palanivel, Thiagarajan

    1992-01-01

    Addresses research results and controversies concerning the ergonomic design of computer work stations ranging from the traditional concerns with anthropometric fashions, work posture, and visual performance to the recent considerations about human information processing capacities and awareness of problem-solving strategies. (eight references)…

  9. Modeling Interaction Effects in Latent Growth Curve Models.

    ERIC Educational Resources Information Center

    Li, Fuzhong; Duncan, Terry E.; Acock, Alan

    2000-01-01

    Presents an extension of the method of estimating interaction effects among latent variables to latent growth curve models developed by K. Joreskog and F. Yang (1996). Illustrates the procedure and discusses results in terms of practical and statistical problems associated with interaction analyses in latent curve models and structural equation…

  10. Modeling Interaction Effects in Latent Growth Curve Models.

    ERIC Educational Resources Information Center

    Li, Fuzhong; Duncan, Terry E.; Acock, Alan

    2000-01-01

    Presents an extension of the method of estimating interaction effects among latent variables to latent growth curve models developed by K. Joreskog and F. Yang (1996). Illustrates the procedure and discusses results in terms of practical and statistical problems associated with interaction analyses in latent curve models and structural equation…

  11. Towards Better Human Robot Interaction: Understand Human Computer Interaction in Social Gaming Using a Video-Enhanced Diary Method

    NASA Astrophysics Data System (ADS)

    See, Swee Lan; Tan, Mitchell; Looi, Qin En

    This paper presents findings from a descriptive research on social gaming. A video-enhanced diary method was used to understand the user experience in social gaming. From this experiment, we found that natural human behavior and gamer’s decision making process can be elicited and speculated during human computer interaction. These are new information that we should consider as they can help us build better human computer interfaces and human robotic interfaces in future.

  12. Impact of Cognitive Architectures on Human-Computer Interaction

    DTIC Science & Technology

    2014-09-01

    Army Research Laboratory Impact of Cognitive Architectures on Human-Computer Interaction by Sidney C Smith ARL-TR-7092 September 2014 Approved for...Proving Ground, MD 21005-5067 ARL-TR-7092 September 2014 Impact of Cognitive Architectures on Human-Computer Interaction Sidney C Smith Computational...PAGES 19b. TELEPHONE NUMBER (Include area code) Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 September 2014 Final Impact of

  13. Behavioural comparison of human-animal (dog) and human-robot (AIBO) interactions.

    PubMed

    Kerepesi, A; Kubinyi, E; Jonsson, G K; Magnusson, M S; Miklósi, A

    2006-07-01

    The behavioural analysis of human-robot interactions can help in developing socially interactive robots. The current study analyzes human-robot interaction with Theme software and the corresponding pattern detection algorithm. The method is based on the analysis of the temporal structure of the interactions by detecting T-patterns in the behaviour. We have compared humans' (children and adults) play behaviour interacting either with an AIBO or a living dog puppy. The analysis based on measuring latencies and frequencies of behavioural units suggested limited differences, e.g. the latency of humans touching the dog/AIBO was similar. In addition other differences could be accounted for by the limited abilities of the robot to interact with objects. Although the number of interactive T-patterns did not significantly differ among the groups but the partner's type (whether humans were playing with dog or AIBO) had a significant effect on the structure of the patterns. Both children and adults terminated T-patterns more frequently when playing with AIBO than when playing with the dog puppy, which suggest that the robot has a limited ability to engage in temporally structured behavioural interactions with humans. As other human studies suggest that the temporal complexity of the interaction is good measure of the partner's attitude, we suggest that more attention should be paid in the future to the robots' ability to engage in cooperative interaction with humans.

  14. Emotion recognition in human-computer interaction.

    PubMed

    Fragopanagos, N; Taylor, J G

    2005-05-01

    In this paper, we outline the approach we have developed to construct an emotion-recognising system. It is based on guidance from psychological studies of emotion, as well as from the nature of emotion in its interaction with attention. A neural network architecture is constructed to be able to handle the fusion of different modalities (facial features, prosody and lexical content in speech). Results from the network are given and their implications discussed, as are implications for future direction for the research.

  15. Human-Computer Interaction (HCI) in Educational Environments: Implications of Understanding Computers as Media.

    ERIC Educational Resources Information Center

    Berg, Gary A.

    2000-01-01

    Reviews literature in the field of human-computer interaction (HCI) as it applies to educational environments. Topics include the origin of HCI; human factors; usability; computer interface design; goals, operations, methods, and selection (GOMS) models; command language versus direct manipulation; hypertext; visual perception; interface…

  16. Pleistocene megafaunal interaction networks became more vulnerable after human arrival.

    PubMed

    Pires, Mathias M; Koch, Paul L; Fariña, Richard A; de Aguiar, Marcus A M; dos Reis, Sérgio F; Guimarães, Paulo R

    2015-09-07

    The end of the Pleistocene was marked by the extinction of almost all large land mammals worldwide except in Africa. Although the debate on Pleistocene extinctions has focused on the roles of climate change and humans, the impact of perturbations depends on properties of ecological communities, such as species composition and the organization of ecological interactions. Here, we combined palaeoecological and ecological data, food-web models and community stability analysis to investigate if differences between Pleistocene and modern mammalian assemblages help us understand why the megafauna died out in the Americas while persisting in Africa. We show Pleistocene and modern assemblages share similar network topology, but differences in richness and body size distributions made Pleistocene communities significantly more vulnerable to the effects of human arrival. The structural changes promoted by humans in Pleistocene networks would have increased the likelihood of unstable dynamics, which may favour extinction cascades in communities facing extrinsic perturbations. Our findings suggest that the basic aspects of the organization of ecological communities may have played an important role in major extinction events in the past. Knowledge of community-level properties and their consequences to dynamics may be critical to understand past and future extinctions. © 2015 The Author(s).

  17. Human-Computer Interaction with Medical Decisions Support Systems

    NASA Technical Reports Server (NTRS)

    Adolf, Jurine A.; Holden, Kritina L.

    1994-01-01

    Decision Support Systems (DSSs) have been available to medical diagnosticians for some time, yet their acceptance and use have not increased with advances in technology and availability of DSS tools. Medical DSSs will be necessary on future long duration space missions, because access to medical resources and personnel will be limited. Human-Computer Interaction (HCI) experts at NASA's Human Factors and Ergonomics Laboratory (HFEL) have been working toward understanding how humans use DSSs, with the goal of being able to identify and solve the problems associated with these systems. Work to date consists of identification of HCI research areas, development of a decision making model, and completion of two experiments dealing with 'anchoring'. Anchoring is a phenomenon in which the decision maker latches on to a starting point and does not make sufficient adjustments when new data are presented. HFEL personnel have replicated a well-known anchoring experiment and have investigated the effects of user level of knowledge. Future work includes further experimentation on level of knowledge, confidence in the source of information and sequential decision making.

  18. Human-Computer Interaction with Medical Decisions Support Systems

    NASA Technical Reports Server (NTRS)

    Adolf, Jurine A.; Holden, Kritina L.

    1994-01-01

    Decision Support Systems (DSSs) have been available to medical diagnosticians for some time, yet their acceptance and use have not increased with advances in technology and availability of DSS tools. Medical DSSs will be necessary on future long duration space missions, because access to medical resources and personnel will be limited. Human-Computer Interaction (HCI) experts at NASA's Human Factors and Ergonomics Laboratory (HFEL) have been working toward understanding how humans use DSSs, with the goal of being able to identify and solve the problems associated with these systems. Work to date consists of identification of HCI research areas, development of a decision making model, and completion of two experiments dealing with 'anchoring'. Anchoring is a phenomenon in which the decision maker latches on to a starting point and does not make sufficient adjustments when new data are presented. HFEL personnel have replicated a well-known anchoring experiment and have investigated the effects of user level of knowledge. Future work includes further experimentation on level of knowledge, confidence in the source of information and sequential decision making.

  19. Pleistocene megafaunal interaction networks became more vulnerable after human arrival

    PubMed Central

    Pires, Mathias M.; Koch, Paul L.; Fariña, Richard A.; de Aguiar, Marcus A. M.; dos Reis, Sérgio F.; Guimarães, Paulo R.

    2015-01-01

    The end of the Pleistocene was marked by the extinction of almost all large land mammals worldwide except in Africa. Although the debate on Pleistocene extinctions has focused on the roles of climate change and humans, the impact of perturbations depends on properties of ecological communities, such as species composition and the organization of ecological interactions. Here, we combined palaeoecological and ecological data, food-web models and community stability analysis to investigate if differences between Pleistocene and modern mammalian assemblages help us understand why the megafauna died out in the Americas while persisting in Africa. We show Pleistocene and modern assemblages share similar network topology, but differences in richness and body size distributions made Pleistocene communities significantly more vulnerable to the effects of human arrival. The structural changes promoted by humans in Pleistocene networks would have increased the likelihood of unstable dynamics, which may favour extinction cascades in communities facing extrinsic perturbations. Our findings suggest that the basic aspects of the organization of ecological communities may have played an important role in major extinction events in the past. Knowledge of community-level properties and their consequences to dynamics may be critical to understand past and future extinctions. PMID:26336175

  20. Evaluating Interactive Instructional Technologies: A Cognitive Model.

    ERIC Educational Resources Information Center

    Tucker, Susan A.

    Strengths and weaknesses of prevailing evaluation models are analyzed, with attention to the role of feedback in each paradigm. A framework is then presented for analyzing issues faced by evaluators of interactive instructional technologies. The current practice of evaluation relies heavily on 3 models developed over 20 years ago: (1) the…

  1. Motor Contagion during Human-Human and Human-Robot Interaction

    PubMed Central

    Bisio, Ambra; Sciutti, Alessandra; Nori, Francesco; Metta, Giorgio; Fadiga, Luciano; Sandini, Giulio; Pozzo, Thierry

    2014-01-01

    Motor resonance mechanisms are known to affect humans' ability to interact with others, yielding the kind of “mutual understanding” that is the basis of social interaction. However, it remains unclear how the partner's action features combine or compete to promote or prevent motor resonance during interaction. To clarify this point, the present study tested whether and how the nature of the visual stimulus and the properties of the observed actions influence observer's motor response, being motor contagion one of the behavioral manifestations of motor resonance. Participants observed a humanoid robot and a human agent move their hands into a pre-specified final position or put an object into a container at various velocities. Their movements, both in the object- and non-object- directed conditions, were characterized by either a smooth/curvilinear or a jerky/segmented trajectory. These trajectories were covered with biological or non-biological kinematics (the latter only by the humanoid robot). After action observation, participants were requested to either reach the indicated final position or to transport a similar object into another container. Results showed that motor contagion appeared for both the interactive partner except when the humanoid robot violated the biological laws of motion. These findings suggest that the observer may transiently match his/her own motor repertoire to that of the observed agent. This matching might mediate the activation of motor resonance, and modulate the spontaneity and the pleasantness of the interaction, whatever the nature of the communication partner. PMID:25153990

  2. Motor contagion during human-human and human-robot interaction.

    PubMed

    Bisio, Ambra; Sciutti, Alessandra; Nori, Francesco; Metta, Giorgio; Fadiga, Luciano; Sandini, Giulio; Pozzo, Thierry

    2014-01-01

    Motor resonance mechanisms are known to affect humans' ability to interact with others, yielding the kind of "mutual understanding" that is the basis of social interaction. However, it remains unclear how the partner's action features combine or compete to promote or prevent motor resonance during interaction. To clarify this point, the present study tested whether and how the nature of the visual stimulus and the properties of the observed actions influence observer's motor response, being motor contagion one of the behavioral manifestations of motor resonance. Participants observed a humanoid robot and a human agent move their hands into a pre-specified final position or put an object into a container at various velocities. Their movements, both in the object- and non-object- directed conditions, were characterized by either a smooth/curvilinear or a jerky/segmented trajectory. These trajectories were covered with biological or non-biological kinematics (the latter only by the humanoid robot). After action observation, participants were requested to either reach the indicated final position or to transport a similar object into another container. Results showed that motor contagion appeared for both the interactive partner except when the humanoid robot violated the biological laws of motion. These findings suggest that the observer may transiently match his/her own motor repertoire to that of the observed agent. This matching might mediate the activation of motor resonance, and modulate the spontaneity and the pleasantness of the interaction, whatever the nature of the communication partner.

  3. Human Modeling For Ground Processing Human Factors Engineering Analysis

    NASA Technical Reports Server (NTRS)

    Tran, Donald; Stambolian, Damon; Henderson, Gena; Barth, Tim

    2011-01-01

    There have been many advancements and accomplishments over that last few years using human modeling for human factors engineering analysis for design of spacecraft and launch vehicles. The key methods used for this are motion capture and computer generated human models. The focus of this paper is to explain the different types of human modeling used currently and in the past at Kennedy Space Center (KSC) currently, and to explain the future plans for human modeling for future spacecraft designs.

  4. Human Modeling for Ground Processing Human Factors Engineering Analysis

    NASA Technical Reports Server (NTRS)

    Stambolian, Damon B.; Lawrence, Brad A.; Stelges, Katrine S.; Steady, Marie-Jeanne O.; Ridgwell, Lora C.; Mills, Robert E.; Henderson, Gena; Tran, Donald; Barth, Tim

    2011-01-01

    There have been many advancements and accomplishments over the last few years using human modeling for human factors engineering analysis for design of spacecraft. The key methods used for this are motion capture and computer generated human models. The focus of this paper is to explain the human modeling currently used at Kennedy Space Center (KSC), and to explain the future plans for human modeling for future spacecraft designs

  5. Applied human factors research at the NASA Johnson Space Center Human-Computer Interaction Laboratory

    NASA Technical Reports Server (NTRS)

    Rudisill, Marianne; Mckay, Timothy D.

    1990-01-01

    The applied human factors research program performed at the NASA Johnson Space Center's Human-Computer Interaction Laboratory is discussed. Research is conducted to advance knowledge in human interaction with computer systems during space crew tasks. In addition, the Laboratory is directly involved in the specification of the human-computer interface (HCI) for space systems in development (e.g., Space Station Freedom) and is providing guidelines and support for HCI design to current and future space missions.

  6. Applied human factors research at the NASA Johnson Space Center Human-Computer Interaction Laboratory

    NASA Technical Reports Server (NTRS)

    Rudisill, Marianne; Mckay, Timothy D.

    1990-01-01

    The applied human factors research program performed at the NASA Johnson Space Center's Human-Computer Interaction Laboratory is discussed. Research is conducted to advance knowledge in human interaction with computer systems during space crew tasks. In addition, the Laboratory is directly involved in the specification of the human-computer interface (HCI) for space systems in development (e.g., Space Station Freedom) and is providing guidelines and support for HCI design to current and future space missions.

  7. Technology-Enhanced Human Interaction in Psychotherapy.

    PubMed

    Imel, Zac E; Caperton, Derek D; Tanana, Michael; Atkins, David C

    2017-03-20

    Psychotherapy is on the verge of a technology-inspired revolution. The concurrent maturation of communication, signal processing, and machine learning technologies begs an earnest look at how these technologies may be used to improve the quality of psychotherapy. Here, we discuss 3 research domains where technology is likely to have a significant impact: (1) mechanism and process, (2) training and feedback, and (3) technology-mediated treatment modalities. For each domain, we describe current and forthcoming examples of how new technologies may change established applications. Moreover, for each domain we present research questions that touch on theoretical, systemic, and implementation issues. Ultimately, psychotherapy is a decidedly human endeavor, and thus the application of modern technology to therapy must capitalize on-and enhance-our human capacities as counselors, students, and supervisors. (PsycINFO Database Record

  8. New Theoretical Approaches for Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Rogers, Yvonne

    2004-01-01

    Presents a critique of recent theoretical developments in the field of human-computer interaction (HCI) together with an overview of HCI practice. This chapter discusses why theoretically based approaches have had little impact on the practice of interaction design and suggests mechanisms to enable designers and researchers to better articulate…

  9. New Theoretical Approaches for Human-Computer Interaction.

    ERIC Educational Resources Information Center

    Rogers, Yvonne

    2004-01-01

    Presents a critique of recent theoretical developments in the field of human-computer interaction (HCI) together with an overview of HCI practice. This chapter discusses why theoretically based approaches have had little impact on the practice of interaction design and suggests mechanisms to enable designers and researchers to better articulate…

  10. On the Emergence of Oligarchy in Human Interaction

    ERIC Educational Resources Information Center

    Mayhew, Bruce H.; Levinger, Roger L.

    1976-01-01

    This study examines how group size affects power structure. Elementary conditions under which human interaction generally occurs constrain power to equalize as the length of the interaction sequence increases and to polarize as the size of the group increases. (Author/DE)

  11. Affect in Human-Robot Interaction

    DTIC Science & Technology

    2014-01-01

    practical applicability, facial emotional expressiveness has received a lot of attention, ranging from realistic robot heads to schematic faces to...Arkin, R. (1998). Behavior-based Robotics. MIT Press. 3. Arkin, R., & Balch, T. (1997). AuRA: Principles and Practice in Review. Journal of...Synthetic Psychology, MIT Press. 11. Breazeal, C. (2003). Emotion and Sociable Humanoid Robots. International Journal of Human-Computer Studies, 59, 119

  12. Behavioral Entropy in Human-Robot Interaction

    DTIC Science & Technology

    2004-01-01

    Department 2 Erwin R. Boer Consulting Brigham Young University San Diego, CA, USA Provo, UT, USA ABSTRACT The ability to quickly and accurately measure...AND ADDRESS(ES) Brigham Young University,Computer Science Department,33361 Talmage Building,Provo,UT,84602 8. PERFORMING ORGANIZATION REPORT NUMBER...in- teraction. To paraphrase Wiener, people work to re- duce entropy so skilled behavior minimizes entropy. This manifests itself in human behavior

  13. Method and apparatus for modeling interactions

    DOEpatents

    Xavier, Patrick G.

    2000-08-08

    A method and apparatus for modeling interactions between bodies. The method comprises representing two bodies undergoing translations and rotations by two hierarchical swept volume representations. Interactions such as nearest approach and collision can be modeled based on the swept body representations. The present invention can serve as a practical tool in motion planning, CAD systems, simulation systems, safety analysis, and applications that require modeling time-based interactions. A body can be represented in the present invention by a union of convex polygons and convex polyhedra. As used generally herein, polyhedron includes polygon, and polyhedra includes polygons. The body undergoing translation can be represented by a swept body representation, where the swept body representation comprises a hierarchical bounding volume representation whose leaves each contain a representation of the region swept by a section of the body during the translation, and where the union of the regions is a superset of the region swept by the surface of the body during translation. Interactions between two bodies thus represented can be modeled by modeling interactions between the convex hulls of the finite sets of discrete points in the swept body representations.

  14. Interactive simulation of needle insertion models.

    PubMed

    DiMaio, Simon P; Salcudean, Septimiu E

    2005-07-01

    A novel interactive virtual needle insertion simulation is presented. The simulation models are based on measured planar tissue deformations and needle insertion forces. Since the force-displacement relationship is only of interest along the needle shaft, a condensation technique is shown to reduce the computational complexity of linear simulation models significantly. As the needle penetrates or is withdrawn from the tissue model, the boundary conditions that determine the tissue and needle motion change. Boundary condition and local material coordinate changes are facilitated by fast low-rank matrix updates. A large-strain elastic needle model is coupled to the tissue models to account for needle deflection and bending during simulated insertion. A haptic environment, based on these novel interactive simulation techniques, allows users to manipulate a three-degree-of-freedom virtual needle as it penetrates virtual tissue models, while experiencing steering torques and lateral needle forces through a planar haptic interface.

  15. Multisite Interactions in Lattice-Gas Models

    NASA Astrophysics Data System (ADS)

    Einstein, T. L.; Sathiyanarayanan, R.

    For detailed applications of lattice-gas models to surface systems, multisite interactions often play at least as significant a role as interactions between pairs of adatoms that are separated by a few lattice spacings. We recall that trio (3-adatom, non-pairwise) interactions do not inevitably create phase boundary asymmetries about half coverage. We discuss a sophisticated application to an experimental system and describe refinements in extracting lattice-gas energies from calculations of total energies of several different ordered overlayers. We describe how lateral relaxations complicate matters when there is direct interaction between the adatoms, an issue that is important when examining the angular dependence of step line tensions. We discuss the connector model as an alternative viewpoint and close with a brief account of recent work on organic molecule overlayers.

  16. Dynamics of the two process model of human sleep regulation

    NASA Astrophysics Data System (ADS)

    Kenngott, Max; McKay, Cavendish

    2011-04-01

    We examine the dynamics of the two process model of human sleep regulation. In this model, sleep propensity is governed by the interaction between a periodic threshold (process C) and a saturating growth/decay (process S). We find that the parameter space of this model admits sleep cycles with a wide variety of characteristics, many of which are not observed in normal human sleepers. We also examine the effects of phase dependent feedback on this model.

  17. An experiment with interactive planning models

    NASA Technical Reports Server (NTRS)

    Beville, J.; Wagner, J. H.; Zannetos, Z. S.

    1970-01-01

    Experiments on decision making in planning problems are described. Executives were tested in dealing with capital investments and competitive pricing decisions under conditions of uncertainty. A software package, the interactive risk analysis model system, was developed, and two controlled experiments were conducted. It is concluded that planning models can aid management, and predicted uses of the models are as a central tool, as an educational tool, to improve consistency in decision making, to improve communications, and as a tool for consensus decision making.

  18. Partonomies for interactive explorable 3D-models of anatomy.

    PubMed Central

    Schubert, R.; Höhne, K. H.

    1998-01-01

    We introduce a concept to model subtle part-whole-semantics for the use with interactive 3d-models of human anatomy. Similar to experiences with modeling partonomies for physical artifacts like machines or buildings we found one unique part-whole-relation to be insufficient to represent anatomical reality. This claim will be illustrated with anatomical examples. According to the requirements these examples demand, a semantic classification of part-whole-relations is introduced. Initial results in modeling anatomical partonomies for a 3d-visualization environment proved this approach to be an promising way to represent anatomy and to enable powerful complex inferences. Images Figure 2 Figure 4 PMID:9929256

  19. Functional interactions as big data in the human brain.

    PubMed

    Turk-Browne, Nicholas B

    2013-11-01

    Noninvasive studies of human brain function hold great potential to unlock mysteries of the human mind. The complexity of data generated by such studies, however, has prompted various simplifying assumptions during analysis. Although this has enabled considerable progress, our current understanding is partly contingent upon these assumptions. An emerging approach embraces the complexity, accounting for the fact that neural representations are widely distributed, neural processes involve interactions between regions, interactions vary by cognitive state, and the space of interactions is massive. Because what you see depends on how you look, such unbiased approaches provide the greatest flexibility for discovery.

  20. Human-Robot Interaction: A Survey

    DTIC Science & Technology

    2007-01-01

    operated devices with no or minimal autonomy (Figure 2.1). In 1898, Nicola Tesla demon - strated a radio-controlled boat, which he described as incorporating...vol. 33, no. 3, pp. 325–336, 2003. [110] M. A. Goodrich, E. R. Boer, J. W. Crandall, R. W. Ricks, and M. L. Quigley, “Behavioral entropy in human...Factors, 2003. [174] P. C. Leger, A. Trebi-Ollennu, J. R. Wright, S. A. Maxwell , R. G. Bonitz, J. J. Biesiadecki, F. R. Hartman, B. K. Cooper, E. T

  1. Flexible Bayesian Human Fecundity Models.

    PubMed

    Kim, Sungduk; Sundaram, Rajeshwari; Buck Louis, Germaine M; Pyper, Cecilia

    2012-12-01

    Human fecundity is an issue of considerable interest for both epidemiological and clinical audiences, and is dependent upon a couple's biologic capacity for reproduction coupled with behaviors that place a couple at risk for pregnancy. Bayesian hierarchical models have been proposed to better model the conception probabilities by accounting for the acts of intercourse around the day of ovulation, i.e., during the fertile window. These models can be viewed in the framework of a generalized nonlinear model with an exponential link. However, a fixed choice of link function may not always provide the best fit, leading to potentially biased estimates for probability of conception. Motivated by this, we propose a general class of models for fecundity by relaxing the choice of the link function under the generalized nonlinear model framework. We use a sample from the Oxford Conception Study (OCS) to illustrate the utility and fit of this general class of models for estimating human conception. Our findings reinforce the need for attention to be paid to the choice of link function in modeling conception, as it may bias the estimation of conception probabilities. Various properties of the proposed models are examined and a Markov chain Monte Carlo sampling algorithm was developed for implementing the Bayesian computations. The deviance information criterion measure and logarithm of pseudo marginal likelihood are used for guiding the choice of links. The supplemental material section contains technical details of the proof of the theorem stated in the paper, and contains further simulation results and analysis.

  2. The Shigella human challenge model.

    PubMed

    Porter, C K; Thura, N; Ranallo, R T; Riddle, M S

    2013-02-01

    Shigella is an important bacterial cause of infectious diarrhoea globally. The Shigella human challenge model has been used since 1946 for a variety of objectives including understanding disease pathogenesis, human immune responses and allowing for an early assessment of vaccine efficacy. A systematic review of the literature regarding experimental shigellosis in human subjects was conducted. Summative estimates were calculated by strain and dose. While a total of 19 studies evaluating nine strains at doses ranging from 10 to 1 × 1010 colony-forming units were identified, most studies utilized the S. sonnei strain 53G and the S. flexneri strain 2457T. Inoculum solution and pre-inoculation buffering has varied over time although diarrhoea attack rates do not appear to increase above 75-80%, and dysentery rates remain fairly constant, highlighting the need for additional dose-ranging studies. Expansion of the model to include additional strains from different serotypes will elucidate serotype and strain-specific outcome variability.

  3. Bridging Animal and Human Models

    PubMed Central

    Barkley-Levenson, Amanda M.; Crabbe, John C.

    2012-01-01

    Genetics play an important role in the development and course of alcohol abuse, and understanding genetic contributions to this disorder may lead to improved preventative and therapeutic strategies in the future. Studies both in humans and in animal models are necessary to fully understand the neurobiology of alcoholism from the molecular to the cognitive level. By dissecting the complex facets of alcoholism into discrete, well-defined phenotypes that are measurable in both human populations and animal models of the disease, researchers will be better able to translate findings across species and integrate the knowledge obtained from various disciplines. Some of the key areas of alcoholism research where consilience between human and animal studies is possible are alcohol withdrawal severity, sensitivity to rewards, impulsivity, and dysregulated alcohol consumption. PMID:23134048

  4. Quark interchange model of baryon interactions

    SciTech Connect

    Maslow, J.N.

    1983-01-01

    The strong interactions at low energy are traditionally described by meson field theories treating hadrons as point-like particles. Here a mesonic quark interchange model (QIM) is presented which takes into account the finite size of the baryons and the internal quark structure of hadrons. The model incorporates the basic quark-gluon coupling of quantum chromodynamics (QCD) and the MIT bag model for color confinement. Because the quark-gluon coupling constant is large and it is assumed that confinement excludes overlap of hadronic quark bags except at high momenta, a non-perturbative method of nuclear interactions is presented. The QIM allows for exchange of quark quantum numbers at the bag boundary between colliding hadrons mediated at short distances by a gluon exchange between two quarks within the hadronic interior. This generates, via a Fierz transformation, an effective space-like t channel exchange of color singlet (q anti-q) states that can be identified with the low lying meson multiplets. Thus, a one boson exchange (OBE) model is obtained that allows for comparison with traditional phenomenological models of nuclear scattering. Inclusion of strange quarks enables calculation of YN scattering. The NN and YN coupling constants and the nucleon form factors show good agreement with experimental values as do the deuteron low energy data and the NN low energy phase shifts. Thus, the QIM provides a simple model of strong interactions that is chirally invariant, includes confinement and allows for an OBE form of hadronic interaction at low energies and momentum transfers.

  5. Polymicrobial Interactions: Impact on Pathogenesis and Human Disease

    PubMed Central

    Peters, Brian M.; Jabra-Rizk, Mary Ann; O'May, Graeme A.; Costerton, J. William

    2012-01-01

    Summary: Microorganisms coexist in a complex milieu of bacteria, fungi, archaea, and viruses on or within the human body, often as multifaceted polymicrobial biofilm communities at mucosal sites and on abiotic surfaces. Only recently have we begun to appreciate the complicated biofilm phenotype during infection; moreover, even less is known about the interactions that occur between microorganisms during polymicrobial growth and their implications in human disease. Therefore, this review focuses on polymicrobial biofilm-mediated infections and examines the contribution of bacterial-bacterial, bacterial-fungal, and bacterial-viral interactions during human infection and potential strategies for protection against such diseases. PMID:22232376

  6. Human Operator Control Strategy Model.

    DTIC Science & Technology

    1980-04-01

    control learning control strategy N computer simulation of motor behavior ABSTRACT (Continue on reverese ide If necesery end Identify by block numbe...Frank Vogler has been a continuing resource during testing and analysis phases. Cooperative Plan students Kirk Hoyer , Bob Baltar, and Bob Hummel have...Introduction ....... .................... .. 79 1. Question 1: Do HOPE models match human behavior to an acceptable extent? .... ............ ... 80

  7. Modeling interactions between political parties and electors

    NASA Astrophysics Data System (ADS)

    Bagarello, F.; Gargano, F.

    2017-09-01

    In this paper we extend some recent results on an operatorial approach to the description of alliances between political parties interacting among themselves and with a basin of electors. In particular, we propose and compare three different models, deducing the dynamics of their related decision functions, i.e. the attitude of each party to form or not an alliance. In the first model the interactions between each party and their electors are considered. We show that these interactions drive the decision functions toward certain asymptotic values depending on the electors only: this is the perfect party, which behaves following the electors' suggestions. The second model is an extension of the first one in which we include a rule which modifies the status of the electors, and of the decision functions as a consequence, at some specific time step. In the third model we neglect the interactions with the electors while we consider cubic and quartic interactions between the parties and we show that we get (slightly oscillating) asymptotic values for the decision functions, close to their initial values. This is the real party, which does not listen to the electors. Several explicit situations are considered in details and numerical results are also shown.

  8. BENEFITS OF POSITIVE HUMAN INTERACTION FOR SOCIALLY-HOUSED CHIMPANZEES

    PubMed Central

    Baker, Kate C

    2010-01-01

    Human interaction as environmental enrichment for chimpanzees (Pan troglodytes) and other primates is widely promoted and believed to be of value, but has been subject to little objective evaluation. This study assessed the effects of positive human interaction (eg relaxed treat feeding, playing, and other forms of social interaction compatible with personnel safety) on the behaviour of adult chimpanzees. Subjects were housed indoors in groups of two or three individuals. The level of interaction during routine care and management (ie in the process of cleaning, feeding, and monitoring) represented the baseline condition. The test condition involved a familiar caretaker spending an additional 10 minutes per day, 5 days a week, with each chimpanzee. This study was designed to assess carry-over effects of interaction on behaviour outside of the context of care staff presence. Therefore, in all phases of the study, data (97 hours of focal animal sampling) were collected only when caretakers were absent from the building. During the increased human interaction phase, the chimpanzees groomed each other more and showed lower levels of the following behaviours: regurgitation/reingestion, other oral abnormal behaviours, inactivity, and reactivity to the displays of neighboring groups. A trend toward reduced agonistic displaying was detected as well. Attempted interactions with the observer shifted significantly from predominantly aggressive to predominantly affiliative in nature. These results suggest that simple, unstructured affiliation between humans and chimpanzees should be a valued component of behavioural management. PMID:20505791

  9. Self-Powered Human-Interactive Transparent Nanopaper Systems.

    PubMed

    Zhong, Junwen; Zhu, Hongli; Zhong, Qize; Dai, Jiaqi; Li, Wenbo; Jang, Soo-Hwan; Yao, Yonggang; Henderson, Doug; Hu, Qiyi; Hu, Liangbing; Zhou, Jun

    2015-07-28

    Self-powered human-interactive but invisible electronics have many applications in anti-theft and anti-fake systems for human society. In this work, for the first time, we demonstrate a transparent paper-based, self-powered, and human-interactive flexible system. The system is based on an electrostatic induction mechanism with no extra power system appended. The self-powered, transparent paper device can be used for a transparent paper-based art anti-theft system in museums or for a smart mapping anti-fake system in precious packaging and documents, by virtue of the advantages of adding/removing freely, having no impairment on the appearance of the protected objects, and being easily mass manufactured. This initial study bridges the transparent nanopaper with a self-powered and human-interactive electronic system, paving the way for the development of smart transparent paper electronics.

  10. Joint action: neurocognitive mechanisms supporting human interaction.

    PubMed

    Bekkering, Harold; de Bruijn, Ellen R A; Cuijpers, Raymond H; Newman-Norlund, Roger; Van Schie, Hein T; Meulenbroek, Ruud

    2009-04-01

    Humans are experts in cooperating with each other when trying to accomplish tasks they cannot achieve alone. Recent studies of joint action have shown that when performing tasks together people strongly rely on the neurocognitive mechanisms that they also use when performing actions individually, that is, they predict the consequences of their co-actor's behavior through internal action simulation. Context-sensitive action monitoring and action selection processes, however, are relatively underrated but crucial ingredients of joint action. In the present paper, we try to correct the somewhat simplified view on joint action by reviewing recent studies of joint action simulation, monitoring, and selection while emphasizing the intricate interrelationships between these processes. We complement our review by defining the contours of a neurologically plausible computational framework of joint action.

  11. Human capabilities in space. [man machine interaction

    NASA Technical Reports Server (NTRS)

    Nicogossian, A. E.

    1984-01-01

    Man's ability to live and perform useful work in space was demonstrated throughout the history of manned space flight. Current planning envisions a multi-functional space station. Man's unique abilities to respond to the unforeseen and to operate at a level of complexity exceeding any reasonable amount of previous planning distinguish him from present day machines. His limitations, however, include his inherent inability to survive without protection, his limited strength, and his propensity to make mistakes when performing repetitive and monotonous tasks. By contrast, an automated system does routine and delicate tasks, exerts force smoothly and precisely, stores, and recalls large amounts of data, and performs deductive reasoning while maintaining a relative insensitivity to the environment. The establishment of a permanent presence of man in space demands that man and machines be appropriately combined in spaceborne systems. To achieve this optimal combination, research is needed in such diverse fields as artificial intelligence, robotics, behavioral psychology, economics, and human factors engineering.

  12. Peer-to-Peer Human-Robot Interaction for Space Exploration

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Nourbakhsh, Illah

    2004-01-01

    NASA has embarked on a long-term program to develop human-robot systems for sustained, affordable space exploration. To support this mission, we are working to improve human-robot interaction and performance on planetary surfaces. Rather than building robots that function as glorified tools, our focus is to enable humans and robots to work as partners and peers. In this paper. we describe our approach, which includes contextual dialogue, cognitive modeling, and metrics-based field testing.

  13. Peer-to-Peer Human-Robot Interaction for Space Exploration

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Nourbakhsh, Illah

    2004-01-01

    NASA has embarked on a long-term program to develop human-robot systems for sustained, affordable space exploration. To support this mission, we are working to improve human-robot interaction and performance on planetary surfaces. Rather than building robots that function as glorified tools, our focus is to enable humans and robots to work as partners and peers. In this paper. we describe our approach, which includes contextual dialogue, cognitive modeling, and metrics-based field testing.

  14. Interactive Visual Analysis within Dynamic Ocean Models

    NASA Astrophysics Data System (ADS)

    Butkiewicz, T.

    2012-12-01

    The many observation and simulation based ocean models available today can provide crucial insights for all fields of marine research and can serve as valuable references when planning data collection missions. However, the increasing size and complexity of these models makes leveraging their contents difficult for end users. Through a combination of data visualization techniques, interactive analysis tools, and new hardware technologies, the data within these models can be made more accessible to domain scientists. We present an interactive system that supports exploratory visual analysis within large-scale ocean flow models. The currents and eddies within the models are illustrated using effective, particle-based flow visualization techniques. Stereoscopic displays and rendering methods are employed to ensure that the user can correctly perceive the complex 3D structures of depth-dependent flow patterns. Interactive analysis tools are provided which allow the user to experiment through the introduction of their customizable virtual dye particles into the models to explore regions of interest. A multi-touch interface provides natural, efficient interaction, with custom multi-touch gestures simplifying the otherwise challenging tasks of navigating and positioning tools within a 3D environment. We demonstrate the potential applications of our visual analysis environment with two examples of real-world significance: Firstly, an example of using customized particles with physics-based behaviors to simulate pollutant release scenarios, including predicting the oil plume path for the 2010 Deepwater Horizon oil spill disaster. Secondly, an interactive tool for plotting and revising proposed autonomous underwater vehicle mission pathlines with respect to the surrounding flow patterns predicted by the model; as these survey vessels have extremely limited energy budgets, designing more efficient paths allows for greater survey areas.

  15. Global Quantitative Modeling of Chromatin Factor Interactions

    PubMed Central

    Zhou, Jian; Troyanskaya, Olga G.

    2014-01-01

    Chromatin is the driver of gene regulation, yet understanding the molecular interactions underlying chromatin factor combinatorial patterns (or the “chromatin codes”) remains a fundamental challenge in chromatin biology. Here we developed a global modeling framework that leverages chromatin profiling data to produce a systems-level view of the macromolecular complex of chromatin. Our model ultilizes maximum entropy modeling with regularization-based structure learning to statistically dissect dependencies between chromatin factors and produce an accurate probability distribution of chromatin code. Our unsupervised quantitative model, trained on genome-wide chromatin profiles of 73 histone marks and chromatin proteins from modENCODE, enabled making various data-driven inferences about chromatin profiles and interactions. We provided a highly accurate predictor of chromatin factor pairwise interactions validated by known experimental evidence, and for the first time enabled higher-order interaction prediction. Our predictions can thus help guide future experimental studies. The model can also serve as an inference engine for predicting unknown chromatin profiles — we demonstrated that with this approach we can leverage data from well-characterized cell types to help understand less-studied cell type or conditions. PMID:24675896

  16. Human cardiovascular model and applications.

    PubMed

    Zhu, K Y; Ang, Alvin; Acharya U, Rajendra; Lim, C M

    2011-10-01

    Cardiovascular diseases (CVDs) can be known as a class of diseases which affect different parts of the cardiovascular system such as the heart or blood vessels. Hemodynamic signals are an important tool used by doctors to diagnose the type of CVD occurred in a patient. Diagnosing the correct type of CVD in a patient early will allow the patient to have the suitable medical treatment. Some examples of CVDs include coronary heart disease, cerebrovascular disease and peripheral arterial disease. A human cardiovascular model is developed in order to simulate different hemodynamic signals of the cardiovascular system. The hemodynamic signals include the blood pressures, flow rates and volumes in various part of the cardiovascular system. This paper presents a model which is able to simulate hemodynamic signals and they are able to represent the human arterial blood pressure accurately. Hence this model can also be used to simulate hypertensive patients in order to design control systems for regulation of blood pressure. Signal verification has been performed and the stability of the model is being investigated. Applications of the human cardiovascular model are also presented.

  17. Centrality of Social Interaction in Human Brain Function.

    PubMed

    Hari, Riitta; Henriksson, Linda; Malinen, Sanna; Parkkonen, Lauri

    2015-10-07

    People are embedded in social interaction that shapes their brains throughout lifetime. Instead of emerging from lower-level cognitive functions, social interaction could be the default mode via which humans communicate with their environment. Should this hypothesis be true, it would have profound implications on how we think about brain functions and how we dissect and simulate them. We suggest that the research on the brain basis of social cognition and interaction should move from passive spectator science to studies including engaged participants and simultaneous recordings from the brains of the interacting persons.

  18. Human immunodeficiency virus type 1, human protein interaction database at NCBI.

    PubMed

    Fu, William; Sanders-Beer, Brigitte E; Katz, Kenneth S; Maglott, Donna R; Pruitt, Kim D; Ptak, Roger G

    2009-01-01

    The 'Human Immunodeficiency Virus Type 1 (HIV-1), Human Protein Interaction Database', available through the National Library of Medicine at www.ncbi.nlm.nih.gov/RefSeq/HIVInteractions, was created to catalog all interactions between HIV-1 and human proteins published in the peer-reviewed literature. The database serves the scientific community exploring the discovery of novel HIV vaccine candidates and therapeutic targets. To facilitate this discovery approach, the following information for each HIV-1 human protein interaction is provided and can be retrieved without restriction by web-based downloads and ftp protocols: Reference Sequence (RefSeq) protein accession numbers, Entrez Gene identification numbers, brief descriptions of the interactions, searchable keywords for interactions and PubMed identification numbers (PMIDs) of journal articles describing the interactions. Currently, 2589 unique HIV-1 to human protein interactions and 5135 brief descriptions of the interactions, with a total of 14,312 PMID references to the original articles reporting the interactions, are stored in this growing database. In addition, all protein-protein interactions documented in the database are integrated into Entrez Gene records and listed in the 'HIV-1 protein interactions' section of Entrez Gene reports. The database is also tightly linked to other databases through Entrez Gene, enabling users to search for an abundance of information related to HIV pathogenesis and replication.

  19. The scaling of human interactions with city size

    PubMed Central

    Schläpfer, Markus; Bettencourt, Luís M. A.; Grauwin, Sébastian; Raschke, Mathias; Claxton, Rob; Smoreda, Zbigniew; West, Geoffrey B.; Ratti, Carlo

    2014-01-01

    The size of cities is known to play a fundamental role in social and economic life. Yet, its relation to the structure of the underlying network of human interactions has not been investigated empirically in detail. In this paper, we map society-wide communication networks to the urban areas of two European countries. We show that both the total number of contacts and the total communication activity grow superlinearly with city population size, according to well-defined scaling relations and resulting from a multiplicative increase that affects most citizens. Perhaps surprisingly, however, the probability that an individual's contacts are also connected with each other remains largely unaffected. These empirical results predict a systematic and scale-invariant acceleration of interaction-based spreading phenomena as cities get bigger, which is numerically confirmed by applying epidemiological models to the studied networks. Our findings should provide a microscopic basis towards understanding the superlinear increase of different socioeconomic quantities with city size, that applies to almost all urban systems and includes, for instance, the creation of new inventions or the prevalence of certain contagious diseases. PMID:24990287

  20. Etintidine-theophylline interaction study in humans.

    PubMed

    Huang, S M; Weintraub, H S; Marriott, T B; Marinan, B; Abels, R; Leese, P T

    1987-01-01

    Etintidine HCl is a potent H2-blocker. The effect of clinical doses of etintidine on the disposition of theophylline was investigated in 10 male volunteers. This was a double-blind, two-way crossover study. Each subject received etintidine (400 mg) or placebo twice a day with meals for 4 days on two occasions (separated by 4 days). On each occasion, the subjects were fasted overnight on Day 3 and were given an oral dose of theophylline elixir (5 mg/kg) 30 min following the administration of the morning dose of etintidine or placebo on Day 4. Blood samples were collected prior to and up to 24 h following the administration of theophylline. Plasma theophylline levels were analysed by HPLC. Theophylline was rapidly absorbed following oral administration of the theophylline elixir to both the placebo and etintidine treatment groups. Comparison of the pharmacokinetic parameters of theophylline between the etintidine and the placebo groups indicates that while etintidine did not significantly (p greater than 0.05) affect the apparent Cmax (11.1 vs 10.0 micrograms ml-1) and Tmax (1.7 vs 1.4 h) values of theophylline, etintidine significantly reduced the oral clearance (0.0200 vs 0.0564 l kg-1 h-1, p = 0.000006) and prolonged the elimination half-life (16.8 vs 6.0 h) of theophylline. The data indicate that etintidine, like cimetidine, extended the elimination of theophylline in humans.

  1. Interaction Effects in Growth Modeling: A Full Model.

    ERIC Educational Resources Information Center

    Wen, Zhonglin; Marsh, Herbert W.; Hau, Kit-Tai

    2002-01-01

    Points out two concerns with recent research by F. Li and others (2000) and T. Duncan and others (1999) that extended the structural equation model of latent interactions developed by K. Joreskog and F. Yang (1996) to latent growth modeling. Used mathematical derivation and a comparison of alternative models fitted to simulated data to develop a…

  2. Interactive Structure (EUCLID) For Static And Dynamic Representation Of Human Body

    NASA Astrophysics Data System (ADS)

    Renaud, Ch.; Steck, R.

    1983-07-01

    A specific software (EUCLID) for static and dynamic representation of human models is described. The data processing system is connected with ERGODATA and used in interactive mode by intrinsic or specific functions. More or less complex representations in 3-D view of models of the human body are developed. Biostereometric and conventional anthropometric raw data from the data bank are processed for different applications in ergonomy.

  3. Interactive Activation Model of Speech Perception.

    DTIC Science & Technology

    1984-11-01

    contract. 0 Elar, .l... & .McC’lelland .1.1. Speech perception a, a cognitive proces,: The interactive act ia- %e., tion model of speech perception. In...attempts to provide a machine solution to the problem of speech perception. A second kind of model, growing out of Cognitive Psychology, attempts to...architectures to cognitive and perceptual problems. We also owe a debt to what we might call the computational connectionists -- those who have applied highly

  4. A human motor control perspective to multiple manipulator modelling.

    PubMed

    Kambhampati, C; Rajasekharan, S

    2003-10-01

    This paper describes the aspects involved in modelling a multi-robot system from a human motor control perspective. The human motor control system has a hierarchical and decentralised structure, and building a control system for a multi-robot system that attains human features would require a decomposable model. Decomposition of a complex robotic system is difficult due to the interactions between the subsystems, so these have to be first separated before the system is modelled. The proposed method of separating the interconnections is applied with the aid of fuzzy modelling to derive a fully decomposable model of two manipulator robots handling a common object.

  5. A fashion model with social interaction

    NASA Astrophysics Data System (ADS)

    Nakayama, Shoichiro; Nakamura, Yasuyuki

    2004-06-01

    In general, it is difficult to investigate social phenomena mathematically or quantitatively due to non-linear interactions. Statistical physics can provide powerful methods for studying social phenomena with interactions, and could be very useful for them. In this study, we take a focus on fashion as a social phenomenon with interaction. The social interaction considered here are “bandwagon effect” and “snob effect.” In the bandwagon effect, the correlation between one's behavior and others is positive. People feel fashion weary or boring when it is overly popular. This is the snob effect. It is assumed that the fashion phenomenon is formed by the aggregation of individual's binary choice, that is, the fashion is adopted or not. We formulate the fashion phenomenon as the logit model, which is based on the random utility theory in social science, especially economics. The model derived here basically has the similarity with the pioneering model by Weidlich (Phys. Rep. 204 (1991) 1), which was derived from the master equation, the Langevin equation, or the Fokker-Planck equation. This study seems to give the behavioral or behaviormetrical foundation to his model. As a result of dynamical analysis, it is found that in the case that both the bandwagon effect and the snob effect work, periodic or chaotic behavior of fashion occurs under certain conditions.

  6. AN INTERACTION MODEL APPLIED TO SUPERVISION.

    ERIC Educational Resources Information Center

    BOYD, ROBERT D.

    THIS STUDY OUTLINES A SMALL GROUP INTERACTION MODEL WHICH CAN BE APPLIED TO SUPERVISION. IT CONSISTS OF THREE CHANNELS -- (1) THE MOTIVATIONAL CHANNEL IN WHICH THE MOTIVATIONAL ASPECT OF AN UTTERANCE (I.E. QUESTIONS, EXCLAMATIONS, ASSERTIONS) IS IDENTIFIED ACCORDING TO THE PARTICULAR EGO CRISIS (TRUST VS. MISTRUST, AUTONOMY VS. SHAME DOUBT,…

  7. An interaction-embedded HMM framework for human behavior understanding: with nursing environments as examples.

    PubMed

    Liu, Chin-De; Chung, Yi-Nung; Julia Chung, Pau-Choo

    2010-09-01

    This paper presents an interaction-embedded hidden Markov model (IE-HMM) framework for automatically detecting and classifying individual human behaviors and group interactions. The proposed framework comprises a switch control (SC) module, an individual duration HMM (IDHMM) module, and an interaction-coupled duration HMM (ICDHMM) module. By analyzing the relative distances between the various participants in each scene, and monitoring the duration for which these distances are maintained, the SC module assigns each participant to an individual behavior unit (comprising a single participant) or an interaction behavior unit (comprising two or more participants). The individual behavior units are passed to the IDHMM module, which classifies the corresponding human behavior in accordance with the pose, motion, and duration information using duration HMM (DHMM). Similarly, the interaction behavior units are dispatched to the ICDHMM module, where the corresponding interaction mode is classified using an integrated scheme comprising multiple coupled-duration HMM (CDHMM), in which each state has an embedded coupled HMM (CHMM). The validity of the IE-HMM framework is confirmed by analyzing the human actions and interactions observed in a nursing home environment. The results confirm that the atomic behavior unit concept embedded in the SC module enables the IE-HMM framework to recognize multiple concurrent actions and interactions within a single scene. Overall, it is shown that the proposed framework has a recognition performance of 100% when applied to the analysis of individual human actions and 95% when applied to that of group interactions.

  8. Statistical pairwise interaction model of stock market

    NASA Astrophysics Data System (ADS)

    Bury, Thomas

    2013-03-01

    Financial markets are a classical example of complex systems as they are compound by many interacting stocks. As such, we can obtain a surprisingly good description of their structure by making the rough simplification of binary daily returns. Spin glass models have been applied and gave some valuable results but at the price of restrictive assumptions on the market dynamics or they are agent-based models with rules designed in order to recover some empirical behaviors. Here we show that the pairwise model is actually a statistically consistent model with the observed first and second moments of the stocks orientation without making such restrictive assumptions. This is done with an approach only based on empirical data of price returns. Our data analysis of six major indices suggests that the actual interaction structure may be thought as an Ising model on a complex network with interaction strengths scaling as the inverse of the system size. This has potentially important implications since many properties of such a model are already known and some techniques of the spin glass theory can be straightforwardly applied. Typical behaviors, as multiple equilibria or metastable states, different characteristic time scales, spatial patterns, order-disorder, could find an explanation in this picture.

  9. Serum fetuin-A and arginase-1 in human obesity model: Is there any interaction between inflammatory status and arginine metabolism?

    PubMed

    Tanrikulu-Küçük, Sevda; Koçak, Hikmet; Öner-İyidoğan, Yildiz; Seyithanoğlu, Muhammed; Topparmak, Erdal; Kayan-Tapan, Tuba

    2015-07-01

    Obesity is a major risk factor for many chronic metabolic diseases such as inflammation, insulin resistance (IR) and fatty liver injury. It was reported that obesity causes some variations on the serum levels of fetuin-A and is associated with arginine metabolism, especially arginase-1 levels. The aim of our study was to evaluate, the interaction and possible changes of these liver over produced proteins, fetuin-A and arginase-1 levels in obesity-related inflammatory status. Study groups were composed of individuals aged between 19 and 63 (n = 62). The control group included healthy subjects with BMI < 25, obese group included obese patients with BMI > 30 and with no other chronic disease. Biochemical markers were determined by an auto-analyzer. Adiponectin, fetuin-A, arginase-1, asymmetric dimethylarginine (ADMA), arginine, Hexanoyl-lysine (HEL) and leptin levels were measured with commercial ELISA immunoassay kits. Nitrite and nitrate were determined with colorimetric assay kit in serum samples. High sensitive C-reactive protein (hsCRP) levels and liver function enzymes activities were higher in the obese group in respect to the control group. Serum fetuin-A, arginase-1 and leptin levels were increased but adiponectin levels were decreased in obese subjects. Fetuin-A levels showed significant correlations with arginase-1 and HOMA-IR. Consequently, we carried out an investigation about higher serum fetuin-A and arginase-1 levels may have an important role in obesity and obesity-related liver damage.

  10. Human interactions with ground-water

    USGS Publications Warehouse

    Zaporozec, A.

    1983-01-01

    Ground-Water could be considered as an immense reservoir, from which only a certain amount of water can be withdrawn without affecting the quantity and quality of water. This amount is determined by the characteristics of the environment in which ground-water occurs and by the interactions of ground-water with precipitation, surface water, and people. It should be recognized that quantity and quality of ground-water are intimately related and should be considered accordingly. Quantity refers to usable water and water is usable for any specific purpose only so long as its quality has not deteriorated beyond acceptable limits. Thus an overall quantitative and qualitative management of ground water is inevitable, and its should also involve the uses of ground-water reservoirs for purposes other than water supply. The main objective of ground-water management is to ensure that ground-water resources will be available in appropriate time and in appropriate quantity and quality to meet the most important demands of our society. Traditional, and obvious uses of ground-water are the extraction of water for water supplies (domestic, municipal, agricultural, and industrial) and the natural discharge feeding lakes and maintaining base flow of streams. Not so obvious are the uses of ground-water reservoirs, the very framework within which ground-water occurs and moves, and in which other fluids or materials can be stored. In the last two decades, ground-water reservoirs have been intensively considered for many other purposes than water supplies. Diversified and very often conflicting uses need to be evaluated and dealt with in the most efficient way in order to determine the importance of each possible use, and to assign priorities of these uses. With rising competition for the use of ground-water reservoirs, we will also need to increase the potential for effective planning of ground-water development and protection. Man's development and use of ground-water necessarily

  11. Analysis of Human-Spacesuit Interaction

    NASA Technical Reports Server (NTRS)

    Thomas, Neha

    2015-01-01

    Astronauts sustain injuries of various natures such as finger delamination, joint pain, and redness due to their interaction with the space suit. The role of the Anthropometry and Biomechanics Facility is to understand the biomechanics, environmental variables, and ergonomics of the suit. This knowledge is then used to make suggestions for improvement in future iterations of the space suit assembly to prevent injuries while allowing astronauts maneuverability, comfort, and tactility. The projects I was involved in were the Extravehicular Mobility Unit (EMU) space suit stiffness study and the glove feasibility study. The EMU project looked at the forces exerted on the shoulder, arm, and wrist when subjects performed kinematic tasks with and without a pressurized suit. The glove study consisted of testing three conditions - the Series 4000 glove, the Phase VI glove, and the no glove condition. With more than forty channels of sensor data total, it was critical to develop programs that could analyze data with basic descriptive statistics and generate relevant graphs to help understand what happens within the space suit and glove. In my project I created a Graphical User Interface (GUI) in MATLAB that would help me visualize what each sensor was doing within a task. The GUI is capable of displaying overlain plots and can be synchronized with video. This was helpful during the stiffness testing to visualize how the forces on the arm acted while the subject performed tasks such as shoulder adduction/abduction and bicep curls. The main project of focus, however, was the glove comparison study. I wrote MATLAB programs which generated movies of the strain vectors during specific tasks. I also generated graphs that summarized the differences between each glove for the strain, shear and FSR sensors. Preliminary results indicate that the Phase VI glove places less strain and shear on the hand. Future work includes continued data analysis of surveys and sensor data. In the end

  12. Neural correlate of human reciprocity in social interactions.

    PubMed

    Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

    2013-01-01

    Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions.

  13. Neural correlate of human reciprocity in social interactions

    PubMed Central

    Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

    2013-01-01

    Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions

  14. Multi-scale modeling of chemotactic interactions

    NASA Astrophysics Data System (ADS)

    Grima, Ramon

    Biological complexity emerges from the synthesis of biochemical, chemical and physical phenomena. In recent years there has been an intense effort in modeling various cellular systems of interest to understand how the observed complexity emerges from the underlying mechanisms. Most modeling approaches are based on a population description of the cells: these methods, though usually amenable to calculation, are only valid in the limit of large numbers of interacting cells. Many systems of interest involve the interaction of a relatively small number of cells; even biological systems composed of thousands of cells have spatially extended regions over which the number density of cells is small. For the latter cases, population descriptions are not valid and individual based models become a necessity. Such models, usually cellular automaton models, have been numerically studied in recent years; however, these models are not usually amenable to analytic calculation. The work presented in this thesis seeks to fulfill a gap in modeling approaches to the understanding of biocomplexity by constructing an individual based model on which analysis is possible, through the methods of statistical physics and the theory of stochastic processes. This model will be used to study the differences between individual based and population based models and the range of applicability of the latter. For the sake of comparison of the two, new efficient computational algorithms are devised for the simulation of both types of models. We finally complete our multiscale study of modeling by investigating the robustness of individual based models; this meaning a comparison of the results of different microscopic descriptions modeling the same underlying phenomena.

  15. [Attempt at computer modeling of evolution of human society].

    PubMed

    Levchenko, V F; Menshutkin, V V

    2009-01-01

    A model of evolution of human society and biosphere, which is based on the concepts of V. I. Vernadskii about noosphere and of L. N. Gumilev about ethnogenesis is developed and studied. The mathematical apparatus of the model is composition of finite stochastic automata. By using this model, a possibility of the global ecological crisis is demonstrated in the case of preservation of the current tendencies of interaction of the biosphere and the human civilization.

  16. Probiotic Lactobacillus casei strain Shirota relieves stress-associated symptoms by modulating the gut-brain interaction in human and animal models.

    PubMed

    Takada, M; Nishida, K; Kataoka-Kato, A; Gondo, Y; Ishikawa, H; Suda, K; Kawai, M; Hoshi, R; Watanabe, O; Igarashi, T; Kuwano, Y; Miyazaki, K; Rokutan, K

    2016-07-01

    This study aimed to examine the effects of Lactobacillus casei strain Shirota (LcS) on gut-brain interactions under stressful conditions. Three double-blind, placebo-controlled trials were conducted to examine the effects of LcS on psychological and physiological stress responses in healthy medical students under academic examination stress. Subjects received LcS-fermented milk or placebo daily for 8 weeks prior to taking a national standardized examination. Subjective anxiety scores, salivary cortisol levels, and the presence of physical symptoms during the intervention were pooled and analyzed. In the animal study, rats were given feed with or without LcS for 2 weeks, then submitted to water avoidance stress (WAS). Plasma corticosterone concentration and the expression of cFos and corticotropin releasing factor (CRF) in the paraventricular nucleus (PVN) were measured immediately after WAS. In an electrophysiological study, gastric vagal afferent nerve activity was monitored after intragastric administration of LcS to urethane-anesthetized rats. Academic stress-induced increases in salivary cortisol levels and the incidence rate of physical symptoms were significantly suppressed in the LcS group compared with the placebo group. In rats pretreated with LcS, WAS-induced increases in plasma corticosterone were significantly suppressed, and the number of CRF-expressing cells in the PVN was reduced. Intragastric administration of LcS stimulated gastric vagal afferent activity in a dose-dependent manner. These findings suggest that LcS may prevent hypersecretion of cortisol and physical symptoms under stressful conditions, possibly through vagal afferent signaling to the brain and reduced stress reactivity in the PVN. © 2016 John Wiley & Sons Ltd.

  17. A Human-Information Interaction Perspective on Augmented Cognition

    SciTech Connect

    Greitzer, Frank L.; Griffith, Douglas

    2006-10-15

    Nearly a half-century ago, J.C.R. Licklider expressed a vision for “man-machine symbiosis,” coupling human brains and computing machines in a partnership that “will think as no human brain has ever thought and process data in a way not approached by the information-handling machines we know today.” Until relatively recently, this vision was largely left idle by human factors engineering (HFE) research that grew over the decades from an initial focus on design of equipment to accommodate human limitations to cognitive systems engineering research to a more recent perspective focusing on design of human-information interaction. These perspective shifts and insights have brought a degree of success to the field in design efforts aimed at enhancing human-system performance. In recent years, the research area of augmented cognition has begun to shift the focus once more not only to enhancing the interaction environment, but also the cognitive abilities of the human operators and decision makers themselves. Ambitious goals of increasing total cognitive capacity through augmented cognition technologies are still on the horizon of this research program. This paper describes a framework within which augmented cognition research may identify requirements that compensate for human information processing shortcomings and augment human potential.

  18. Mouse Models of Human Phenylketonuria

    PubMed Central

    Shedlovsky, A.; McDonald, J. D.; Symula, D.; Dove, W. F.

    1993-01-01

    Phenylketonuria (PKU) results from a deficiency in phenylalanine hydroxylase, the enzyme catalyzing the conversion of phenylalanine (PHE) to tyrosine. Although this inborn error of metabolism was among the first in humans to be understood biochemically and genetically, little is known of the mechanism(s) involved in the pathology of PKU. We have combined mouse germline mutagenesis with screens for hyperphenylalaninemia to isolate three mutants deficient in phenylalanine hydroxylase (PAH) activity and cross-reactive protein. Two of these have reduced PAH mRNA and display characteristics of untreated human PKU patients. A low PHE diet partially reverses these abnormalities. Our success in using high frequency random germline point mutagenesis to obtain appropriate disease models illustrates how such mutagenesis can complement the emergent power of targeted mutagenesis in the mouse. The mutants now can be used as models in studying both maternal PKU and somatic gene therapy. PMID:8375656

  19. Developing a Framework for Intuitive Human-Computer Interaction

    PubMed Central

    O’Brien, Marita A.; Rogers, Wendy A.; Fisk, Arthur D.

    2014-01-01

    Many technology marketing materials tout the intuitive nature of products, but current human-computer interaction (HCI) guidelines provide limited methods to help designers create this experience beyond making them easy to use. This paper proposes a definition for intuitive interaction with specific attributes to allow designers to create products that elicit the target experience. Review of relevant literatures provides empirical evidence for the suggested working definition of intuitive HCI: interactions between humans and high technology in lenient learning environments that allow the human to use a combination of prior experience and feedforward methods to achieve an individual’s functional and abstract goals. Core concepts supporting this definition were compiled into an organizational framework that includes: seeking user goals, performing well-learned behavior, determining what to do next, metacognition, knowledge in the head, and knowledge in the world. This paper describes these concepts and proposes design approaches that could facilitate intuitive behavior and suggests areas for further research. PMID:25552895

  20. Developing a Framework for Intuitive Human-Computer Interaction.

    PubMed

    O'Brien, Marita A; Rogers, Wendy A; Fisk, Arthur D

    2008-09-01

    Many technology marketing materials tout the intuitive nature of products, but current human-computer interaction (HCI) guidelines provide limited methods to help designers create this experience beyond making them easy to use. This paper proposes a definition for intuitive interaction with specific attributes to allow designers to create products that elicit the target experience. Review of relevant literatures provides empirical evidence for the suggested working definition of intuitive HCI: interactions between humans and high technology in lenient learning environments that allow the human to use a combination of prior experience and feedforward methods to achieve an individual's functional and abstract goals. Core concepts supporting this definition were compiled into an organizational framework that includes: seeking user goals, performing well-learned behavior, determining what to do next, metacognition, knowledge in the head, and knowledge in the world. This paper describes these concepts and proposes design approaches that could facilitate intuitive behavior and suggests areas for further research.

  1. Development of an interactive anatomical three-dimensional eye model.

    PubMed

    Allen, Lauren K; Bhattacharyya, Siddhartha; Wilson, Timothy D

    2015-01-01

    The discrete anatomy of the eye's intricate oculomotor system is conceptually difficult for novice students to grasp. This is problematic given that this group of muscles represents one of the most common sites of clinical intervention in the treatment of ocular motility disorders and other eye disorders. This project was designed to develop a digital, interactive, three-dimensional (3D) model of the muscles and cranial nerves of the oculomotor system. Development of the 3D model utilized data from the Visible Human Project (VHP) dataset that was refined using multiple forms of 3D software. The model was then paired with a virtual user interface in order to create a novel 3D learning tool for the human oculomotor system. Development of the virtual eye model was done while attempting to adhere to the principles of cognitive load theory (CLT) and the reduction of extraneous load in particular. The detailed approach, digital tools employed, and the CLT guidelines are described herein.

  2. Structural principles within the human-virus protein-protein interaction network

    PubMed Central

    Franzosa, Eric A.; Xia, Yu

    2011-01-01

    General properties of the antagonistic biomolecular interactions between viruses and their hosts (exogenous interactions) remain poorly understood, and may differ significantly from known principles governing the cooperative interactions within the host (endogenous interactions). Systems biology approaches have been applied to study the combined interaction networks of virus and human proteins, but such efforts have so far revealed only low-resolution patterns of host-virus interaction. Here, we layer curated and predicted 3D structural models of human-virus and human-human protein complexes on top of traditional interaction networks to reconstruct the human-virus structural interaction network. This approach reveals atomic resolution, mechanistic patterns of host-virus interaction, and facilitates systematic comparison with the host’s endogenous interactions. We find that exogenous interfaces tend to overlap with and mimic endogenous interfaces, thereby competing with endogenous binding partners. The endogenous interfaces mimicked by viral proteins tend to participate in multiple endogenous interactions which are transient and regulatory in nature. While interface overlap in the endogenous network results largely from gene duplication followed by divergent evolution, viral proteins frequently achieve interface mimicry without any sequence or structural similarity to an endogenous binding partner. Finally, while endogenous interfaces tend to evolve more slowly than the rest of the protein surface, exogenous interfaces—including many sites of endogenous-exogenous overlap—tend to evolve faster, consistent with an evolutionary “arms race” between host and pathogen. These significant biophysical, functional, and evolutionary differences between host-pathogen and within-host protein-protein interactions highlight the distinct consequences of antagonism versus cooperation in biological networks. PMID:21680884

  3. Human enterovirus 71 protein interaction network prompts antiviral drug repositioning.

    PubMed

    Han, Lu; Li, Kang; Jin, Chaozhi; Wang, Jian; Li, Qingjun; Zhang, Qiling; Cheng, Qiyue; Yang, Jing; Bo, Xiaochen; Wang, Shengqi

    2017-02-21

    As a predominant cause of human hand, foot, and mouth disease, enterovirus 71 (EV71) infection may lead to serious diseases and result in severe consequences that threaten public health and cause widespread panic. Although the systematic identification of physical interactions between viral proteins and host proteins provides initial information for the recognition of the cellular mechanism involved in viral infection and the development of new therapies, EV71-host protein interactions have not been explored. Here, we identified interactions between EV71 proteins and host cellular proteins and confirmed the functional relationships of EV71-interacting proteins (EIPs) with virus proliferation and infection by integrating a human protein interaction network and by functional annotation. We found that most EIPs had known interactions with other viruses. We also predicted ATP6V0C as a broad-spectrum essential host factor and validated its essentiality for EV71 infection in vitro. EIPs and their interacting proteins were more likely to be targets of anti-inflammatory and neurological drugs, indicating their potential to serve as host-oriented antiviral targets. Thus, we used a connectivity map to find drugs that inhibited EIP expression. We predicted tanespimycin as a candidate and demonstrated its antiviral efficiency in vitro. These findings provide the first systematic identification of EV71-host protein interactions, an analysis of EIP protein characteristics and a demonstration of their value in developing host-oriented antiviral therapies.

  4. Human enterovirus 71 protein interaction network prompts antiviral drug repositioning

    PubMed Central

    Han, Lu; Li, Kang; Jin, Chaozhi; Wang, Jian; Li, Qingjun; Zhang, Qiling; Cheng, Qiyue; Yang, Jing; Bo, Xiaochen; Wang, Shengqi

    2017-01-01

    As a predominant cause of human hand, foot, and mouth disease, enterovirus 71 (EV71) infection may lead to serious diseases and result in severe consequences that threaten public health and cause widespread panic. Although the systematic identification of physical interactions between viral proteins and host proteins provides initial information for the recognition of the cellular mechanism involved in viral infection and the development of new therapies, EV71-host protein interactions have not been explored. Here, we identified interactions between EV71 proteins and host cellular proteins and confirmed the functional relationships of EV71-interacting proteins (EIPs) with virus proliferation and infection by integrating a human protein interaction network and by functional annotation. We found that most EIPs had known interactions with other viruses. We also predicted ATP6V0C as a broad-spectrum essential host factor and validated its essentiality for EV71 infection in vitro. EIPs and their interacting proteins were more likely to be targets of anti-inflammatory and neurological drugs, indicating their potential to serve as host-oriented antiviral targets. Thus, we used a connectivity map to find drugs that inhibited EIP expression. We predicted tanespimycin as a candidate and demonstrated its antiviral efficiency in vitro. These findings provide the first systematic identification of EV71-host protein interactions, an analysis of EIP protein characteristics and a demonstration of their value in developing host-oriented antiviral therapies. PMID:28220872

  5. Modeling of Human Joint Structures.

    DTIC Science & Technology

    1982-09-01

    Radial Lateral " epicondyle Olecranon Radius Ulna Figure 3. Lateral aspect of the right elbow joint. -17- Annular Ligament This strong band encircles... elbow joint, knee joint, human joints, shoulder joint, ankle joint, joint models, hip joint, ligaments. 20. ABSTRACT (Continue on reverse side If...ligaments. -A rather extended discussion of the articulations and anatomical descriptions of the elbow , shoulder, hip, knee and ankle joints are

  6. Algebraic Turbulence-Chemistry Interaction Model

    NASA Technical Reports Server (NTRS)

    Norris, Andrew T.

    2012-01-01

    The results of a series of Perfectly Stirred Reactor (PSR) and Partially Stirred Reactor (PaSR) simulations are compared to each other over a wide range of operating conditions. It is found that the PaSR results can be simulated by a PSR solution with just an adjusted chemical reaction rate. A simple expression has been developed that gives the required change in reaction rate for a PSR solution to simulate the PaSR results. This expression is the basis of a simple turbulence-chemistry interaction model. The interaction model that has been developed is intended for use with simple one-step global reaction mechanisms and for steady-state flow simulations. Due to the simplicity of the model there is very little additional computational cost in adding it to existing CFD codes.

  7. Human agency beliefs influence behaviour during virtual social interactions.

    PubMed

    Caruana, Nathan; Spirou, Dean; Brock, Jon

    2017-01-01

    In recent years, with the emergence of relatively inexpensive and accessible virtual reality technologies, it is now possible to deliver compelling and realistic simulations of human-to-human interaction. Neuroimaging studies have shown that, when participants believe they are interacting via a virtual interface with another human agent, they show different patterns of brain activity compared to when they know that their virtual partner is computer-controlled. The suggestion is that users adopt an "intentional stance" by attributing mental states to their virtual partner. However, it remains unclear how beliefs in the agency of a virtual partner influence participants' behaviour and subjective experience of the interaction. We investigated this issue in the context of a cooperative "joint attention" game in which participants interacted via an eye tracker with a virtual onscreen partner, directing each other's eye gaze to different screen locations. Half of the participants were correctly informed that their partner was controlled by a computer algorithm ("Computer" condition). The other half were misled into believing that the virtual character was controlled by a second participant in another room ("Human" condition). Those in the "Human" condition were slower to make eye contact with their partner and more likely to try and guide their partner before they had established mutual eye contact than participants in the "Computer" condition. They also responded more rapidly when their partner was guiding them, although the same effect was also found for a control condition in which they responded to an arrow cue. Results confirm the influence of human agency beliefs on behaviour in this virtual social interaction context. They further suggest that researchers and developers attempting to simulate social interactions should consider the impact of agency beliefs on user experience in other social contexts, and their effect on the achievement of the application's goals.

  8. Peppytides: Interactive Models of Polypeptide Chains

    SciTech Connect

    Zuckermann, Ron; Chakraborty, Promita; Derisi, Joe

    2014-01-21

    Peppytides are scaled, 3D-printed models of polypeptide chains that can be folded into accurate protein structures. Designed and created by Berkeley Lab Researcher, Promita Chakraborty, and Berkeley Lab Senior Scientist, Dr. Ron Zuckermann, Peppytides are accurate physical models of polypeptide chains that anyone can interact with and fold intro various protein structures - proving to be a great educational tool, resulting in a deeper understanding of these fascinating structures and how they function. Build your own Peppytide model and learn about how nature's machines fold into their intricate architectures!

  9. Peppytides: Interactive Models of Polypeptide Chains

    ScienceCinema

    Zuckermann, Ron; Chakraborty, Promita; Derisi, Joe

    2016-07-12

    Peppytides are scaled, 3D-printed models of polypeptide chains that can be folded into accurate protein structures. Designed and created by Berkeley Lab Researcher, Promita Chakraborty, and Berkeley Lab Senior Scientist, Dr. Ron Zuckermann, Peppytides are accurate physical models of polypeptide chains that anyone can interact with and fold intro various protein structures - proving to be a great educational tool, resulting in a deeper understanding of these fascinating structures and how they function. Build your own Peppytide model and learn about how nature's machines fold into their intricate architectures!

  10. Human-Computer Interaction, Tourism and Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Cipolla Ficarra, Francisco V.

    We present a state of the art of the human-computer interaction aimed at tourism and cultural heritage in some cities of the European Mediterranean. In the work an analysis is made of the main problems deriving from training understood as business and which can derail the continuous growth of the HCI, the new technologies and tourism industry. Through a semiotic and epistemological study the current mistakes in the context of the interrelations of the formal and factual sciences will be detected and also the human factors that have an influence on the professionals devoted to the development of interactive systems in order to safeguard and boost cultural heritage.

  11. Motivating forces of human actions. Neuroimaging reward and social interaction.