Atomic switch networks as complex adaptive systems

NASA Astrophysics Data System (ADS)

Scharnhorst, Kelsey S.; Carbajal, Juan P.; Aguilera, Renato C.; Sandouk, Eric J.; Aono, Masakazu; Stieg, Adam Z.; Gimzewski, James K.

2018-03-01

Complexity is an increasingly crucial aspect of societal, environmental and biological phenomena. Using a dense unorganized network of synthetic synapses it is shown that a complex adaptive system can be physically created on a microchip built especially for complex problems. These neuro-inspired atomic switch networks (ASNs) are a dynamic system with inherent and distributed memory, recurrent pathways, and up to a billion interacting elements. We demonstrate key parameters describing self-organized behavior such as non-linearity, power law dynamics, and multistate switching regimes. Device dynamics are then investigated using a feedback loop which provides control over current and voltage power-law behavior. Wide ranging prospective applications include understanding and eventually predicting future events that display complex emergent behavior in the critical regime.

Statistical inference of empirical constituents in partitioned analysis from integral-effect experiments: An application in thermo-mechanical coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, Garrison N.; Atamturktur, Sez; Brown, D. Andrew

Rapid advancements in parallel computing over the last two decades have enabled simulations of complex, coupled systems through partitioning. In partitioned analysis, independently developed constituent models communicate, representing dependencies between multiple physical phenomena that occur in the full system. Figure 1 schematically demonstrates a coupled system with two constituent models, each resolving different physical behavior. In this figure, the constituent model, denoted as the “consumer,” relies upon some input parameter that is being provided by the constituent model acting as a “feeder”. The role of the feeder model is to map operating conditions (i.e. those that are stimulating the process)more » to consumer inputs, thus providing functional inputs to the consumer model*. Problems arise if the feeder model cannot be built–a challenge that is prevalent for highly complex systems in extreme operational conditions that push the limits of our understanding of underlying physical behavior. Often, these are also the situations where separate-effect experiments isolating the physical phenomena are not available; meaning that experimentally determining the unknown constituent behavior is not possible (Bauer and Holland, 1995; Unal et al., 2013), and that integral-effect experiments that reflect the behavior of the complete system tend to be the only available observations. In this paper, the authors advocate for the usefulness of integral-effect experiments in furthering a model developer’s knowledge of the physics principles governing the system behavior of interest.« less

Statistical inference of empirical constituents in partitioned analysis from integral-effect experiments: An application in thermo-mechanical coupling

DOE PAGES

Stevens, Garrison N.; Atamturktur, Sez; Brown, D. Andrew; ...

2018-04-16

Rapid advancements in parallel computing over the last two decades have enabled simulations of complex, coupled systems through partitioning. In partitioned analysis, independently developed constituent models communicate, representing dependencies between multiple physical phenomena that occur in the full system. Figure 1 schematically demonstrates a coupled system with two constituent models, each resolving different physical behavior. In this figure, the constituent model, denoted as the “consumer,” relies upon some input parameter that is being provided by the constituent model acting as a “feeder”. The role of the feeder model is to map operating conditions (i.e. those that are stimulating the process)more » to consumer inputs, thus providing functional inputs to the consumer model*. Problems arise if the feeder model cannot be built–a challenge that is prevalent for highly complex systems in extreme operational conditions that push the limits of our understanding of underlying physical behavior. Often, these are also the situations where separate-effect experiments isolating the physical phenomena are not available; meaning that experimentally determining the unknown constituent behavior is not possible (Bauer and Holland, 1995; Unal et al., 2013), and that integral-effect experiments that reflect the behavior of the complete system tend to be the only available observations. In this paper, the authors advocate for the usefulness of integral-effect experiments in furthering a model developer’s knowledge of the physics principles governing the system behavior of interest.« less

The Relationship of Living Environment with Behavioral and Fitness Outcomes by Sex: an Exploratory Study in College-aged Students.

PubMed

Shaffer, Kaelah; Bopp, Melissa; Papalia, Zack; Sims, Dangaia; Bopp, Christopher M

2017-01-01

Although physical activity (PA) is associated with several health benefits, there is a marked decline during college years, which is an influential period for the development of health behaviors. This study examined the relationship of neighborhood and living environment with behavioral (PA and sedentary behavior) and fitness outcomes by sex. Participants were college students that participated in a fitness assessment, followed by a survey that measured self-reported exercise and perception of one's environment (sidewalks, crime, traffic, access to PA resources in their neighborhood and/or apartment complex). Pearson correlations examined the relationship between behavioral (moderate and vigorous PA, sedentary behavior, active travel) and fitness outcomes (VO2max, percent body fat, body mass index, push-ups, curl-ups, blood lipids and glucose) with environmental measures separately by sex. Among participants (n=444; female=211, male n=234) environment was significantly related to PA and fitness, with noted differences by sex. For males, seeing others exercising in the neighborhood and in their apartment complex, using neighborhood bike lanes, crime and the number of PA resources at their apartment complex were associated with behavioral and fitness outcomes. Among females, sidewalks in the neighborhood, seeing others exercising, using neighborhood bike lanes and number of PA apartment complex resources were significantly correlated with fitness and behavioral outcomes. These findings suggest a possible relationship between students' objectively measured fitness and their environment for PA. Future implications include the development of policies to create student housing that supports physical activity and expansion of campus wellness initiatives to off-campus locations.

Use and perception of the environment: cultural and developmental processes

Treesearch

Martin M. Chemers; Irwin Altman

1977-01-01

This paper presents a "social systems" orientation for integrating the diverse aspects of environment, culture, and individual behavior. It suggests that a wide range of variables, including the physical environment, cultural and social processes, environmental perceptions and cognitions, behavior, and products of behavior, are connected in a complex,...

Self-Regulation in the Midst of Complexity: A Case Study of High School Physics Students Engaged in Ill-Structured Problem Solving

ERIC Educational Resources Information Center

Milbourne, Jeffrey David

2016-01-01

The purpose of this dissertation study was to explore the experiences of high school physics students who were solving complex, ill-structured problems, in an effort to better understand how self-regulatory behavior mediated the project experience. Consistent with Voss, Green, Post, and Penner's (1983) conception of an ill-structured problem in…

Skill Acquisition in Physical Education: A Speculative Perspective

ERIC Educational Resources Information Center

Smith, Wayne W.

2011-01-01

How we learn motor skills has always been of interest to physical educators. Contemporary conceptual frameworks about motor skill learning draw from earlier behavioral and cognitive psychology learning theories. As a point of departure this paper foregrounds complexity theorizing, arguing that skill is contingent upon the performer's physical and…

Review Article: Shallow Draughts--Larsen-Freeman and Cameron on Complexity

ERIC Educational Resources Information Center

Gregg, Kevin R.

2010-01-01

Complexity theory is a field of physics that studies the nature and behavior of complex systems, systems whose elements interact in complex and unpredictable ways. Recent years have seen a number of attempts to extend its scope to the biological and social sciences, and now Larsen-Freeman and Cameron offer a view of applied linguistics from a…

Entanglement entropy and complexity for one-dimensional holographic superconductors

NASA Astrophysics Data System (ADS)

Kord Zangeneh, Mahdi; Ong, Yen Chin; Wang, Bin

2017-08-01

Holographic superconductor is an important arena for holography, as it allows concrete calculations to further understand the dictionary between bulk physics and boundary physics. An important quantity of recent interest is the holographic complexity. Conflicting claims had been made in the literature concerning the behavior of holographic complexity during phase transition. We clarify this issue by performing a numerical study on one-dimensional holographic superconductor. Our investigation shows that holographic complexity does not behave in the same way as holographic entanglement entropy. Nevertheless, the universal terms of both quantities are finite and reflect the phase transition at the same critical temperature.

Using Remote Sensing Data to Constrain Models of Fault Interactions and Plate Boundary Deformation

NASA Astrophysics Data System (ADS)

Glasscoe, M. T.; Donnellan, A.; Lyzenga, G. A.; Parker, J. W.; Milliner, C. W. D.

2016-12-01

Determining the distribution of slip and behavior of fault interactions at plate boundaries is a complex problem. Field and remotely sensed data often lack the necessary coverage to fully resolve fault behavior. However, realistic physical models may be used to more accurately characterize the complex behavior of faults constrained with observed data, such as GPS, InSAR, and SfM. These results will improve the utility of using combined models and data to estimate earthquake potential and characterize plate boundary behavior. Plate boundary faults exhibit complex behavior, with partitioned slip and distributed deformation. To investigate what fraction of slip becomes distributed deformation off major faults, we examine a model fault embedded within a damage zone of reduced elastic rigidity that narrows with depth and forward model the slip and resulting surface deformation. The fault segments and slip distributions are modeled using the JPL GeoFEST software. GeoFEST (Geophysical Finite Element Simulation Tool) is a two- and three-dimensional finite element software package for modeling solid stress and strain in geophysical and other continuum domain applications [Lyzenga, et al., 2000; Glasscoe, et al., 2004; Parker, et al., 2008, 2010]. New methods to advance geohazards research using computer simulations and remotely sensed observations for model validation are required to understand fault slip, the complex nature of fault interaction and plate boundary deformation. These models help enhance our understanding of the underlying processes, such as transient deformation and fault creep, and can aid in developing observation strategies for sUAV, airborne, and upcoming satellite missions seeking to determine how faults behave and interact and assess their associated hazard. Models will also help to characterize this behavior, which will enable improvements in hazard estimation. Validating the model results against remotely sensed observations will allow us to better constrain fault zone rheology and physical properties, having implications for the overall understanding of earthquake physics, fault interactions, plate boundary deformation and earthquake hazard, preparedness and risk reduction.

Physics, stability, and dynamics of supply networks

NASA Astrophysics Data System (ADS)

Helbing, Dirk; Lämmer, Stefan; Seidel, Thomas; Šeba, Pétr; Płatkowski, Tadeusz

2004-12-01

We show how to treat supply networks as physical transport problems governed by balance equations and equations for the adaptation of production speeds. Although the nonlinear behavior is different, the linearized set of coupled differential equations is formally related to those of mechanical or electrical oscillator networks. Supply networks possess interesting features due to their complex topology and directed links. We derive analytical conditions for absolute and convective instabilities. The empirically observed “bullwhip effect” in supply chains is explained as a form of convective instability based on resonance effects. Moreover, it is generalized to arbitrary supply networks. Their related eigenvalues are usually complex, depending on the network structure (even without loops). Therefore, their generic behavior is characterized by damped or growing oscillations. We also show that regular distribution networks possess two negative eigenvalues only, but perturbations generate a spectrum of complex eigenvalues.

A chaotic view of behavior change: a quantum leap for health promotion.

PubMed

Resnicow, Ken; Vaughan, Roger

2006-09-12

The study of health behavior change, including nutrition and physical activity behaviors, has been rooted in a cognitive-rational paradigm. Change is conceptualized as a linear, deterministic process where individuals weigh pros and cons, and at the point at which the benefits outweigh the cost change occurs. Consistent with this paradigm, the associated statistical models have almost exclusively assumed a linear relationship between psychosocial predictors and behavior. Such a perspective however, fails to account for non-linear, quantum influences on human thought and action. Consider why after years of false starts and failed attempts, a person succeeds at increasing their physical activity, eating healthier or losing weight. Or, why after years of success a person relapses. This paper discusses a competing view of health behavior change that was presented at the 2006 annual ISBNPA meeting in Boston. Rather than viewing behavior change from a linear perspective it can be viewed as a quantum event that can be understood through the lens of Chaos Theory and Complex Dynamic Systems. Key principles of Chaos Theory and Complex Dynamic Systems relevant to understanding health behavior change include: 1) Chaotic systems can be mathematically modeled but are nearly impossible to predict; 2) Chaotic systems are sensitive to initial conditions; 3) Complex Systems involve multiple component parts that interact in a nonlinear fashion; and 4) The results of Complex Systems are often greater than the sum of their parts. Accordingly, small changes in knowledge, attitude, efficacy, etc may dramatically alter motivation and behavioral outcomes. And the interaction of such variables can yield almost infinite potential patterns of motivation and behavior change. In the linear paradigm unaccounted for variance is generally relegated to the catch all "error" term, when in fact such "error" may represent the chaotic component of the process. The linear and chaotic paradigms are however, not mutually exclusive, as behavior change may include both chaotic and cognitive processes. Studies of addiction suggest that many decisions to change are quantum rather than planned events; motivation arrives as opposed to being planned. Moreover, changes made through quantum processes appear more enduring than those that involve more rational, planned processes. How such processes may apply to nutrition and physical activity behavior and related interventions merits examination.

eHealth technologies to support nutrition and physical activity behaviors in diabetes self-management.

PubMed

Rollo, Megan E; Aguiar, Elroy J; Williams, Rebecca L; Wynne, Katie; Kriss, Michelle; Callister, Robin; Collins, Clare E

2016-01-01

Diabetes is a chronic, complex condition requiring sound knowledge and self-management skills to optimize glycemic control and health outcomes. Dietary intake and physical activity are key diabetes self-management (DSM) behaviors that require tailored education and support. Electronic health (eHealth) technologies have a demonstrated potential for assisting individuals with DSM behaviors. This review provides examples of technologies used to support nutrition and physical activity behaviors in the context of DSM. Technologies covered include those widely used for DSM, such as web-based programs and mobile phone and smartphone applications. In addition, examples of novel tools such as virtual and augmented reality, video games, computer vision for dietary carbohydrate monitoring, and wearable devices are provided. The challenges to, and facilitators for, the use of eHealth technologies in DSM are discussed. Strategies to support the implementation of eHealth technologies within practice and suggestions for future research to enhance nutrition and physical activity behaviors as a part of broader DSM are provided.

eHealth technologies to support nutrition and physical activity behaviors in diabetes self-management

PubMed Central

Rollo, Megan E; Aguiar, Elroy J; Williams, Rebecca L; Wynne, Katie; Kriss, Michelle; Callister, Robin; Collins, Clare E

2016-01-01

Diabetes is a chronic, complex condition requiring sound knowledge and self-management skills to optimize glycemic control and health outcomes. Dietary intake and physical activity are key diabetes self-management (DSM) behaviors that require tailored education and support. Electronic health (eHealth) technologies have a demonstrated potential for assisting individuals with DSM behaviors. This review provides examples of technologies used to support nutrition and physical activity behaviors in the context of DSM. Technologies covered include those widely used for DSM, such as web-based programs and mobile phone and smartphone applications. In addition, examples of novel tools such as virtual and augmented reality, video games, computer vision for dietary carbohydrate monitoring, and wearable devices are provided. The challenges to, and facilitators for, the use of eHealth technologies in DSM are discussed. Strategies to support the implementation of eHealth technologies within practice and suggestions for future research to enhance nutrition and physical activity behaviors as a part of broader DSM are provided. PMID:27853384

VBOT: Motivating computational and complex systems fluencies with constructionist virtual/physical robotics

NASA Astrophysics Data System (ADS)

Berland, Matthew W.

As scientists use the tools of computational and complex systems theory to broaden science perspectives (e.g., Bar-Yam, 1997; Holland, 1995; Wolfram, 2002), so can middle-school students broaden their perspectives using appropriate tools. The goals of this dissertation project are to build, study, evaluate, and compare activities designed to foster both computational and complex systems fluencies through collaborative constructionist virtual and physical robotics. In these activities, each student builds an agent (e.g., a robot-bird) that must interact with fellow students' agents to generate a complex aggregate (e.g., a flock of robot-birds) in a participatory simulation environment (Wilensky & Stroup, 1999a). In a participatory simulation, students collaborate by acting in a common space, teaching each other, and discussing content with one another. As a result, the students improve both their computational fluency and their complex systems fluency, where fluency is defined as the ability to both consume and produce relevant content (DiSessa, 2000). To date, several systems have been designed to foster computational and complex systems fluencies through computer programming and collaborative play (e.g., Hancock, 2003; Wilensky & Stroup, 1999b); this study suggests that, by supporting the relevant fluencies through collaborative play, they become mutually reinforcing. In this work, I will present both the design of the VBOT virtual/physical constructionist robotics learning environment and a comparative study of student interaction with the virtual and physical environments across four middle-school classrooms, focusing on the contrast in systems perspectives differently afforded by the two environments. In particular, I found that while performance gains were similar overall, the physical environment supported agent perspectives on aggregate behavior, and the virtual environment supported aggregate perspectives on agent behavior. The primary research questions are: (1) What are the relative affordances of virtual and physical constructionist robotics systems towards computational and complex systems fluencies? (2) What can middle school students learn using computational/complex systems learning environments in a collaborative setting? (3) In what ways are these environments and activities effective in teaching students computational and complex systems fluencies?

Physical Behavior in Older Persons during Daily Life: Insights from Instrumented Shoes.

PubMed

Moufawad El Achkar, Christopher; Lenoble-Hoskovec, Constanze; Paraschiv-Ionescu, Anisoara; Major, Kristof; Büla, Christophe; Aminian, Kamiar

2016-08-03

Activity level and gait parameters during daily life are important indicators for clinicians because they can provide critical insights into modifications of mobility and function over time. Wearable activity monitoring has been gaining momentum in daily life health assessment. Consequently, this study seeks to validate an algorithm for the classification of daily life activities and to provide a detailed gait analysis in older adults. A system consisting of an inertial sensor combined with a pressure sensing insole has been developed. Using an algorithm that we previously validated during a semi structured protocol, activities in 10 healthy elderly participants were recorded and compared to a wearable reference system over a 4 h recording period at home. Detailed gait parameters were calculated from inertial sensors. Dynamics of physical behavior were characterized using barcodes that express the measure of behavioral complexity. Activity classification based on the algorithm led to a 93% accuracy in classifying basic activities of daily life, i.e., sitting, standing, and walking. Gait analysis emphasizes the importance of metrics such as foot clearance in daily life assessment. Results also underline that measures of physical behavior and gait performance are complementary, especially since gait parameters were not correlated to complexity. Participants gave positive feedback regarding the use of the instrumented shoes. These results extend previous observations in showing the concurrent validity of the instrumented shoes compared to a body-worn reference system for daily-life physical behavior monitoring in older adults.

Developing the School Physical Activity and Nutrition Environment Tool to Measure Qualities of the Obesogenic Context

ERIC Educational Resources Information Center

John, Deborah H.; Gunter, Katherine; Jackson, Jennifer A.; Manore, Melinda

2016-01-01

Background: Practical tools are needed that reliably measure the complex physical activity (PA) and nutrition environments of elementary schools that influence children's health and learning behaviors for obesity prevention. The School Physical Activity and Nutrition-Environment Tool (SPAN-ET) was developed and beta tested in 6 rural Oregon…

Econophysics: from Game Theory and Information Theory to Quantum Mechanics

NASA Astrophysics Data System (ADS)

Jimenez, Edward; Moya, Douglas

2005-03-01

Rationality is the universal invariant among human behavior, universe physical laws and ordered and complex biological systems. Econophysics isboth the use of physical concepts in Finance and Economics, and the use of Information Economics in Physics. In special, we will show that it is possible to obtain the Quantum Mechanics principles using Information and Game Theory.

Fast Quantum Algorithm for Predicting Descriptive Statistics of Stochastic Processes

NASA Technical Reports Server (NTRS)

Williams Colin P.

1999-01-01

Stochastic processes are used as a modeling tool in several sub-fields of physics, biology, and finance. Analytic understanding of the long term behavior of such processes is only tractable for very simple types of stochastic processes such as Markovian processes. However, in real world applications more complex stochastic processes often arise. In physics, the complicating factor might be nonlinearities; in biology it might be memory effects; and in finance is might be the non-random intentional behavior of participants in a market. In the absence of analytic insight, one is forced to understand these more complex stochastic processes via numerical simulation techniques. In this paper we present a quantum algorithm for performing such simulations. In particular, we show how a quantum algorithm can predict arbitrary descriptive statistics (moments) of N-step stochastic processes in just O(square root of N) time. That is, the quantum complexity is the square root of the classical complexity for performing such simulations. This is a significant speedup in comparison to the current state of the art.

Agent-Based Models in Social Physics

NASA Astrophysics Data System (ADS)

Quang, Le Anh; Jung, Nam; Cho, Eun Sung; Choi, Jae Han; Lee, Jae Woo

2018-06-01

We review the agent-based models (ABM) on social physics including econophysics. The ABM consists of agent, system space, and external environment. The agent is autonomous and decides his/her behavior by interacting with the neighbors or the external environment with the rules of behavior. Agents are irrational because they have only limited information when they make decisions. They adapt using learning from past memories. Agents have various attributes and are heterogeneous. ABM is a non-equilibrium complex system that exhibits various emergence phenomena. The social complexity ABM describes human behavioral characteristics. In ABMs of econophysics, we introduce the Sugarscape model and the artificial market models. We review minority games and majority games in ABMs of game theory. Social flow ABM introduces crowding, evacuation, traffic congestion, and pedestrian dynamics. We also review ABM for opinion dynamics and voter model. We discuss features and advantages and disadvantages of Netlogo, Repast, Swarm, and Mason, which are representative platforms for implementing ABM.

End-Directedness and Context in Nonliving Dissipative Systems

NASA Astrophysics Data System (ADS)

Dixon, James A.; Kay, Bruce A.; Davis, Tehran J.; Kondepudi, Dilip

Biological organisms are distinguished from non-living systems, in part, by their ability to choose and strive towards particular ends. This end-directed behavior is seen across all five biological kingdoms, from single-celled organisms to the most advanced primates. The ubiquitous nature of end-directedness, across such a wide variety of biological entities, suggests that a deeper principle may be at work. We propose that end-directedness, rather than being a special ability of living systems, is actually a fundamental property of a larger class of physical systems, called dissipative structures, which are formed and maintained by the flow of energy and matter. Our work shows that dissipative structures "behave so as to persist", seeking states that increase their rate of entropy production, and thus facilitate their own persistence. In addition, we suggest that biological entities create their exquisite sensitivity to context by interweaving this fundamental end-directedness with the contextual and physical constraints of their environments. The result is a repertoire of complex behavior. We provide an example of such complex behavior emerging from contextual and physical constraints coupled with end-directedness.

Simulating adsorption of U(VI) under transient groundwater flow and hydrochemistry: Physical versus chemical nonequilibrium model

USGS Publications Warehouse

Greskowiak, J.; Hay, M.B.; Prommer, H.; Liu, C.; Post, V.E.A.; Ma, R.; Davis, J.A.; Zheng, C.; Zachara, J.M.

2011-01-01

Coupled intragrain diffusional mass transfer and nonlinear surface complexation processes play an important role in the transport behavior of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes were analyzed and compared: (1) the physical nonequilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface complexation reactions in the intragrain regions and approximates the diffusive mass exchange between the immobile intragrain pore water and the advective pore water as multirate first-order mass transfer and (2) the chemical nonequilibrium approach that approximates the diffusion-limited intragrain surface complexation reactions by a set of multiple first-order surface complexation reaction kinetics, thereby eliminating the explicit treatment of aqueous speciation in the intragrain pore water. A model comparison has been carried out for column and field scale scenarios, representing the highly transient hydrological and geochemical conditions in the U(VI)-contaminated aquifer at the Hanford 300A site, Washington, USA. It was found that the response of U(VI) mass transfer behavior to hydrogeochemically induced changes in U(VI) adsorption strength was more pronounced in the physical than in the chemical nonequilibrium model. The magnitude of the differences in model behavior depended particularly on the degree of disequilibrium between the advective and immobile phase U(VI) concentrations. While a clear difference in U(VI) transport behavior between the two models was noticeable for the column-scale scenarios, only minor differences were found for the Hanford 300A field scale scenarios, where the model-generated disequilibrium conditions were less pronounced as a result of frequent groundwater flow reversals. Copyright 2011 by the American Geophysical Union.

Health-related fitness profiles in adolescents with complex congenital heart disease.

PubMed

Klausen, Susanne Hwiid; Wetterslev, Jørn; Søndergaard, Lars; Andersen, Lars L; Mikkelsen, Ulla Ramer; Dideriksen, Kasper; Zoffmann, Vibeke; Moons, Philip

2015-04-01

This study investigates whether subgroups of different health-related fitness (HrF) profiles exist among girls and boys with complex congenital heart disease (ConHD) and how these are associated with lifestyle behaviors. We measured the cardiorespiratory fitness, muscle strength, and body composition of 158 adolescents aged 13-16 years with previous surgery for a complex ConHD. Data on lifestyle behaviors were collected concomitantly between October 2010 and April 2013. A cluster analysis was conducted to identify profiles with similar HrF. For comparisons between clusters, multivariate analyses of covariance were used to test the differences in lifestyle behaviors. Three distinct profiles were formed: (1) Robust (43, 27%; 20 girls and 23 boys); (2) Moderately Robust (85, 54%; 37 girls and 48 boys); and (3) Less robust (30, 19%; 9 girls and 21 boys). The participants in the Robust clusters reported leading a physically active lifestyle and participants in the Less robust cluster reported leading a sedentary lifestyle. Diagnoses were evenly distributed between clusters. The cluster analysis attributed some of the variability in cardiorespiratory fitness among adolescents with complex ConHD to lifestyle behaviors and physical activity. Profiling of HrF offers a valuable new option in the management of person-centered health promotion. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Managing Complexity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chassin, David P.; Posse, Christian; Malard, Joel M.

2004-08-01

Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust controlmore » strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.« less

Experimental econophysics: Complexity, self-organization, and emergent properties

NASA Astrophysics Data System (ADS)

Huang, J. P.

2015-03-01

Experimental econophysics is concerned with statistical physics of humans in the laboratory, and it is based on controlled human experiments developed by physicists to study some problems related to economics or finance. It relies on controlled human experiments in the laboratory together with agent-based modeling (for computer simulations and/or analytical theory), with an attempt to reveal the general cause-effect relationship between specific conditions and emergent properties of real economic/financial markets (a kind of complex adaptive systems). Here I review the latest progress in the field, namely, stylized facts, herd behavior, contrarian behavior, spontaneous cooperation, partial information, and risk management. Also, I highlight the connections between such progress and other topics of traditional statistical physics. The main theme of the review is to show diverse emergent properties of the laboratory markets, originating from self-organization due to the nonlinear interactions among heterogeneous humans or agents (complexity).

A new universality class in corpus of texts; A statistical physics study

NASA Astrophysics Data System (ADS)

Najafi, Elham; Darooneh, Amir H.

2018-05-01

Text can be regarded as a complex system. There are some methods in statistical physics which can be used to study this system. In this work, by means of statistical physics methods, we reveal new universal behaviors of texts associating with the fractality values of words in a text. The fractality measure indicates the importance of words in a text by considering distribution pattern of words throughout the text. We observed a power law relation between fractality of text and vocabulary size for texts and corpora. We also observed this behavior in studying biological data.

Oscillations and Multiple Equilibria in Microvascular Blood Flow.

PubMed

Karst, Nathaniel J; Storey, Brian D; Geddes, John B

2015-07-01

We investigate the existence of oscillatory dynamics and multiple steady-state flow rates in a network with a simple topology and in vivo microvascular blood flow constitutive laws. Unlike many previous analytic studies, we employ the most biologically relevant models of the physical properties of whole blood. Through a combination of analytic and numeric techniques, we predict in a series of two-parameter bifurcation diagrams a range of dynamical behaviors, including multiple equilibria flow configurations, simple oscillations in volumetric flow rate, and multiple coexistent limit cycles at physically realizable parameters. We show that complexity in network topology is not necessary for complex behaviors to arise and that nonlinear rheology, in particular the plasma skimming effect, is sufficient to support oscillatory dynamics similar to those observed in vivo.

Running from Disease: Molecular Mechanisms Associating Dopamine and Leptin Signaling in the Brain with Physical Inactivity, Obesity, and Type 2 Diabetes.

PubMed

Ruegsegger, Gregory N; Booth, Frank W

2017-01-01

Physical inactivity is a primary contributor to diseases such as obesity, cardiovascular disease, and type 2 diabetes. Accelerometry data suggest that a majority of US adults fail to perform substantial levels of physical activity needed to improve health. Thus, understanding the molecular factors that stimulate physical activity, and physical inactivity, is imperative for the development of strategies to reduce sedentary behavior and in turn prevent chronic disease. Despite many of the well-known health benefits of physical activity being described, little is known about genetic and biological factors that may influence this complex behavior. The mesolimbic dopamine system regulates motivating and rewarding behavior as well as motor movement. Here, we present data supporting the hypothesis that obesity may mechanistically lower voluntary physical activity levels via dopamine dysregulation. In doing so, we review data that suggest mesolimbic dopamine activity is a strong contributor to voluntary physical activity behavior. We also summarize findings suggesting that obesity leads to central dopaminergic dysfunction, which in turn contributes to reductions in physical activity that often accompany obesity. Additionally, we highlight examples in which central leptin activity influences physical activity levels in a dopamine-dependent manner. Future elucidation of these mechanisms will help support strategies to increase physical activity levels in obese patients and prevent diseases caused by physical inactivity.

A Model-Based Approach to Engineering Behavior of Complex Aerospace Systems

NASA Technical Reports Server (NTRS)

Ingham, Michel; Day, John; Donahue, Kenneth; Kadesch, Alex; Kennedy, Andrew; Khan, Mohammed Omair; Post, Ethan; Standley, Shaun

2012-01-01

One of the most challenging yet poorly defined aspects of engineering a complex aerospace system is behavior engineering, including definition, specification, design, implementation, and verification and validation of the system's behaviors. This is especially true for behaviors of highly autonomous and intelligent systems. Behavior engineering is more of an art than a science. As a process it is generally ad-hoc, poorly specified, and inconsistently applied from one project to the next. It uses largely informal representations, and results in system behavior being documented in a wide variety of disparate documents. To address this problem, JPL has undertaken a pilot project to apply its institutional capabilities in Model-Based Systems Engineering to the challenge of specifying complex spacecraft system behavior. This paper describes the results of the work in progress on this project. In particular, we discuss our approach to modeling spacecraft behavior including 1) requirements and design flowdown from system-level to subsystem-level, 2) patterns for behavior decomposition, 3) allocation of behaviors to physical elements in the system, and 4) patterns for capturing V&V activities associated with behavioral requirements. We provide examples of interesting behavior specification patterns, and discuss findings from the pilot project.

[Physical inactivity behavior: is this an adaptive answer that is normal and inappropriate to public health in the 21st century?].

PubMed

Sittarame, Frédéric; Golay, Alain

2013-03-27

Physical inactivity or sedentary behavior is more and more widespread, a fairly recent worldwide health phenomenon. It currently takes the shape of a chronic illness with dire consequences. Its factors are influenced by personal motivation and the social and physical environments in which people live. Screening for physical inactivity or sedentary behavior enables patients and caregivers to become fully aware of its risks. The health benefits of simply adding walking to our everyday activities or adding low-impact movement in oureveryday lives would improve the health, the quality of life and longevity for most adults. Caregivers can successfully assist patients in changing their behavior. For certain patients suffering from diseases or complex cases, interdisciplinary specialized surveillance care is useful. There is a need to put this issue at the forefront of public health and adopt a positive stance towards strategies in our places of work, our schools, our means of transportation and overall urban planning and development.

Uranium plume persistence impacted by hydrologic and geochemical heterogeneity in the groundwater and river water interaction zone of Hanford site

NASA Astrophysics Data System (ADS)

Chen, X.; Zachara, J. M.; Vermeul, V. R.; Freshley, M.; Hammond, G. E.

2015-12-01

The behavior of a persistent uranium plume in an extended groundwater- river water (GW-SW) interaction zone at the DOE Hanford site is dominantly controlled by river stage fluctuations in the adjacent Columbia River. The plume behavior is further complicated by substantial heterogeneity in physical and geochemical properties of the host aquifer sediments. Multi-scale field and laboratory experiments and reactive transport modeling were integrated to understand the complex plume behavior influenced by highly variable hydrologic and geochemical conditions in time and space. In this presentation we (1) describe multiple data sets from field-scale uranium adsorption and desorption experiments performed at our experimental well-field, (2) develop a reactive transport model that incorporates hydrologic and geochemical heterogeneities characterized from multi-scale and multi-type datasets and a surface complexation reaction network based on laboratory studies, and (3) compare the modeling and observation results to provide insights on how to refine the conceptual model and reduce prediction uncertainties. The experimental results revealed significant spatial variability in uranium adsorption/desorption behavior, while modeling demonstrated that ambient hydrologic and geochemical conditions and heterogeneities in sediment physical and chemical properties both contributed to complex plume behavior and its persistence. Our analysis provides important insights into the characterization, understanding, modeling, and remediation of groundwater contaminant plumes influenced by surface water and groundwater interactions.

Evidence from pupillometry and fMRI indicates reduced neural response during vicarious social pain but not physical pain in autism.

PubMed

Krach, Sören; Kamp-Becker, Inge; Einhäuser, Wolfgang; Sommer, Jens; Frässle, Stefan; Jansen, Andreas; Rademacher, Lena; Müller-Pinzler, Laura; Gazzola, Valeria; Paulus, Frieder M

2015-11-01

Autism spectrum disorder (ASD) is characterized by substantial social deficits. The notion that dysfunctions in neural circuits involved in sharing another's affect explain these deficits is appealing, but has received only modest experimental support. Here we evaluated a complex paradigm on the vicarious social pain of embarrassment to probe social deficits in ASD as to whether it is more potent than paradigms currently in use. To do so we acquired pupillometry and fMRI in young adults with ASD and matched healthy controls. During a simple vicarious physical pain task no differences emerged between groups in behavior, pupillometry, and neural activation of the anterior insula (AIC) and anterior cingulate cortex (ACC). In contrast, processing complex vicarious social pain yielded reduced responses in ASD on all physiological measures of sharing another's affect. The reduced activity within the AIC was thereby explained by the severity of autistic symptoms in the social and affective domain. Additionally, behavioral responses lacked correspondence with the anterior cingulate and anterior insula cortex activity found in controls. Instead, behavioral responses in ASD were associated with hippocampal activity. The observed dissociation echoes the clinical observations that deficits in ASD are most pronounced in complex social situations and simple tasks may not probe the dysfunctions in neural pathways involved in sharing affect. Our results are highly relevant because individuals with ASD may have preserved abilities to share another's physical pain but still have problems with the vicarious representation of more complex emotions that matter in life. © 2015 Wiley Periodicals, Inc.

Assessment of electrical conductivity as a surrogate measurement for water samples in a tracer injection experiment

USDA-ARS?s Scientific Manuscript database

The transport behavior of solutes in streams depends on chemical, physical, biological, and hydrodynamic processes. Although it is a very complex system, it is known that this behavior is greatly influenced by surface and subsurface flows. For this reason, tracer injection in the water flows is one ...

Recent advances in mathematical criminology. Comment on "Statistical physics of crime: A review" by M.R. D'Orsogna and M. Perc

NASA Astrophysics Data System (ADS)

Rodríguez, Nancy

2015-03-01

The use of mathematical tools has long proved to be useful in gaining understanding of complex systems in physics [1]. Recently, many researchers have realized that there is an analogy between emerging phenomena in complex social systems and complex physical or biological systems [4,5,12]. This realization has particularly benefited the modeling and understanding of crime, a ubiquitous phenomena that is far from being understood. In fact, when one is interested in the bulk behavior of patterns that emerge from small and seemingly unrelated interactions as well as decisions that occur at the individual level, the mathematical tools that have been developed in statistical physics, game theory, network theory, dynamical systems, and partial differential equations can be useful in shedding light into the dynamics of these patterns [2-4,6,12].

Moral Enhancement Using Non-invasive Brain Stimulation

PubMed Central

Darby, R. Ryan; Pascual-Leone, Alvaro

2017-01-01

Biomedical enhancement refers to the use of biomedical interventions to improve capacities beyond normal, rather than to treat deficiencies due to diseases. Enhancement can target physical or cognitive capacities, but also complex human behaviors such as morality. However, the complexity of normal moral behavior makes it unlikely that morality is a single capacity that can be deficient or enhanced. Instead, our central hypothesis will be that moral behavior results from multiple, interacting cognitive-affective networks in the brain. First, we will test this hypothesis by reviewing evidence for modulation of moral behavior using non-invasive brain stimulation. Next, we will discuss how this evidence affects ethical issues related to the use of moral enhancement. We end with the conclusion that while brain stimulation has the potential to alter moral behavior, such alteration is unlikely to improve moral behavior in all situations, and may even lead to less morally desirable behavior in some instances. PMID:28275345

Troubleshooting Complex Equipment in the Military Services: Research and Prospects. Technical Report No. 92.

ERIC Educational Resources Information Center

Bond, Nicholas A.; Towne, Douglas M.

Psychological approaches to the troubleshooting of complex military equipments are designed to improve the selection, motivation, and training of technicians. Methods for enhancing the understanding of the physical relations in equipment, the hierarchical analysis and practice of sub-skills, and the general logic of searching behavior are aspects…

Characterizing time series: when Granger causality triggers complex networks

NASA Astrophysics Data System (ADS)

Ge, Tian; Cui, Yindong; Lin, Wei; Kurths, Jürgen; Liu, Chong

2012-08-01

In this paper, we propose a new approach to characterize time series with noise perturbations in both the time and frequency domains by combining Granger causality and complex networks. We construct directed and weighted complex networks from time series and use representative network measures to describe their physical and topological properties. Through analyzing the typical dynamical behaviors of some physical models and the MIT-BIHMassachusetts Institute of Technology-Beth Israel Hospital. human electrocardiogram data sets, we show that the proposed approach is able to capture and characterize various dynamics and has much potential for analyzing real-world time series of rather short length.

Challenges in the analysis of complex systems: introduction and overview

NASA Astrophysics Data System (ADS)

Hastings, Harold M.; Davidsen, Jörn; Leung, Henry

2017-12-01

One of the main challenges of modern physics is to provide a systematic understanding of systems far from equilibrium exhibiting emergent behavior. Prominent examples of such complex systems include, but are not limited to the cardiac electrical system, the brain, the power grid, social systems, material failure and earthquakes, and the climate system. Due to the technological advances over the last decade, the amount of observations and data available to characterize complex systems and their dynamics, as well as the capability to process that data, has increased substantially. The present issue discusses a cross section of the current research on complex systems, with a focus on novel experimental and data-driven approaches to complex systems that provide the necessary platform to model the behavior of such systems.

Modeling Power Systems as Complex Adaptive Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chassin, David P.; Malard, Joel M.; Posse, Christian

2004-12-30

Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We reviewmore » and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.« less

Gender Differences in Health Risk Behaviors and Physical Activity among Middle School Students

ERIC Educational Resources Information Center

Wu, Tsu-Yin; Rose, Sherry E.; Bancroft, Joanna M.

2006-01-01

Adolescence is a period of accelerated growth and change, bridging the complex transition from childhood to adulthood. This period offers adolescents an opportunity to begin planning for their futures and to adopt healthy attitudes about risk behaviors that can continue into adulthood, thus setting the stage for a lifetime of desirable health…

Is Pelvic-Floor Muscle Training a Physical Therapy or a Behavioral Therapy? A Call to Name and Report the Physical, Cognitive, and Behavioral Elements.

PubMed

Frawley, Helena C; Dean, Sarah G; Slade, Susan C; Hay-Smith, E Jean C

2017-04-01

This perspective article explores whether pelvic-floor muscle training (PFMT) for the management of female urinary incontinence and prolapse is a physical therapy or a behavioral therapy. The primary aim is to demonstrate that it is both. A secondary aim is to show that the plethora of terms used for PFMT is potentially confusing and that current terminology inadequately represents the full intent, content, and delivery of this complex intervention. While physical therapists may be familiar with exercise terms, the details are often incompletely reported; furthermore, physical therapists are less familiar with the terminology used in accurately representing cognitive and behavioral therapy interventions, which results in these elements being even less well reported. Thus, an additional aim is to provide greater clarity in the terminology used in the reporting of PFMT interventions, specifically, descriptions of the exercise and behavioral elements. First, PFMT is described as a physical therapy and as an exercise therapy informed predominantly by the discipline of physical therapy. However, effective implementation requires use of the cognitive and behavioral perspectives of the discipline of psychology. Second, the theoretical underpinning of the psychology-informed elements of PFMT is summarized. Third, to address some identified limitations and confusion in current terminology and reporting, recommendations for ways in which physical therapists can incorporate the psychology-informed elements of PFMT alongside the more familiar exercise therapy-informed elements are made. Fourth, an example of how both elements can be described and reported in a PFMT intervention is provided. In summary, this perspective explores the underlying concepts of PFMT to demonstrate that it is both a physical intervention and a behavioral intervention and that it can and should be described as such, and an example of the integration of these elements into clinical practice is provided. © 2017 American Physical Therapy Association.

Evaluating crown fire rate of spread predictions from physics-based models

Treesearch

C. M. Hoffman; J. Ziegler; J. Canfield; R. R. Linn; W. Mell; C. H. Sieg; F. Pimont

2015-01-01

Modeling the behavior of crown fires is challenging due to the complex set of coupled processes that drive the characteristics of a spreading wildfire and the large range of spatial and temporal scales over which these processes occur. Detailed physics-based modeling approaches such as FIRETEC and the Wildland Urban Interface Fire Dynamics Simulator (WFDS) simulate...

Time-spatial model on the dynamics of the proliferation of Aedes aegypti

NASA Astrophysics Data System (ADS)

Gouvêa, Maury Meirelles, Jr.

2017-03-01

Some complex physical systems, such as cellular regulation, ecosystems, and societies, can be represented by local interactions between agents. Then, complex behaviors may emerge. A cellular automaton is a discrete dynamic system with these features. Among the several complex systems, epidemic diseases are given special attention by researchers with respect to their dynamics. Understanding the behavior of an epidemic may well benefit a society. For instance, different proliferation scenarios may be produced and a prevention policy set. This paper presents a new simulation method of the time-spatial spread of the Dengue mosquito with a cellular automaton. Thus, it will be possible to create different dissemination scenarios and preventive policies for these in several regions. Simulations were performed with different initial conditions and parameters as a result of which the behavior of the proposed method was characterized.

Simple universal models capture all classical spin physics.

PubMed

De las Cuevas, Gemma; Cubitt, Toby S

2016-03-11

Spin models are used in many studies of complex systems because they exhibit rich macroscopic behavior despite their microscopic simplicity. Here, we prove that all the physics of every classical spin model is reproduced in the low-energy sector of certain "universal models," with at most polynomial overhead. This holds for classical models with discrete or continuous degrees of freedom. We prove necessary and sufficient conditions for a spin model to be universal and show that one of the simplest and most widely studied spin models, the two-dimensional Ising model with fields, is universal. Our results may facilitate physical simulations of Hamiltonians with complex interactions. Copyright © 2016, American Association for the Advancement of Science.

Trends in the salience of data collected in a multi user virtual environment: An exploratory study

NASA Astrophysics Data System (ADS)

Tutwiler, M. Shane

In this study, by exploring patterns in the degree of physical salience of the data the students collected, I investigated the relationship between the level of students' tendency to frame explanations in terms of complex patterns and evidence of how they attend to and select data in support of their developing understandings of causal relationships. I accomplished this by analyzing longitudinal data collected as part of a larger study of 143 7th grade students (clustered within 36 teams, 5 teachers, and 2 schools in the same Northeastern school district) as they navigated and collected data in an ecosystems-based multi-user virtual environment curriculum known as the EcoMUVE Pond module (Metcalf, Kamarainen, Tutwiler, Grotzer, Dede, 2011) . Using individual growth modeling (Singer & Willett, 2003) I found no direct link between student pre-intervention tendency to offer explanations containing complex causal components and patterns of physical salience-driven data collection (average physical salience level, number of low physical salience data points collected, and proportion of low physical salience data points collected), though prior science content knowledge did affect the initial status and rate of change of outcomes in the average physical salience level and proportion of low physical salience data collected over time. The findings of this study suggest two issues for consideration about the use of MUVEs to study student data collection behaviors in complex spaces. Firstly, the structure of the curriculum in which the MUVE is embedded might have a direct effect on what types of data students choose to collect. This undercuts our ability to make inferences about student-driven decisions to collect specific types of data, and suggests that a more open-ended curricular model might be better suited to this type of inquiry. Secondly, differences between teachers' choices in how to facilitate the units likely contribute to the variance in student data collection behaviors between students with different teachers. This foreshadows external validity issues in studies that use behaviors of students within a single class to develop "detectors" of student latent traits (e.g., Baker, Corbett, Roll, Koedinger, 2008).

Complex network problems in physics, computer science and biology

NASA Astrophysics Data System (ADS)

Cojocaru, Radu Ionut

There is a close relation between physics and mathematics and the exchange of ideas between these two sciences are well established. However until few years ago there was no such a close relation between physics and computer science. Even more, only recently biologists started to use methods and tools from statistical physics in order to study the behavior of complex system. In this thesis we concentrate on applying and analyzing several methods borrowed from computer science to biology and also we use methods from statistical physics in solving hard problems from computer science. In recent years physicists have been interested in studying the behavior of complex networks. Physics is an experimental science in which theoretical predictions are compared to experiments. In this definition, the term prediction plays a very important role: although the system is complex, it is still possible to get predictions for its behavior, but these predictions are of a probabilistic nature. Spin glasses, lattice gases or the Potts model are a few examples of complex systems in physics. Spin glasses and many frustrated antiferromagnets map exactly to computer science problems in the NP-hard class defined in Chapter 1. In Chapter 1 we discuss a common result from artificial intelligence (AI) which shows that there are some problems which are NP-complete, with the implication that these problems are difficult to solve. We introduce a few well known hard problems from computer science (Satisfiability, Coloring, Vertex Cover together with Maximum Independent Set and Number Partitioning) and then discuss their mapping to problems from physics. In Chapter 2 we provide a short review of combinatorial optimization algorithms and their applications to ground state problems in disordered systems. We discuss the cavity method initially developed for studying the Sherrington-Kirkpatrick model of spin glasses. We extend this model to the study of a specific case of spin glass on the Bethe lattice at zero temperature and then we apply this formalism to the K-SAT problem defined in Chapter 1. The phase transition which physicists study often corresponds to a change in the computational complexity of the corresponding computer science problem. Chapter 3 presents phase transitions which are specific to the problems discussed in Chapter 1 and also known results for the K-SAT problem. We discuss the replica method and experimental evidences of replica symmetry breaking. The physics approach to hard problems is based on replica methods which are difficult to understand. In Chapter 4 we develop novel methods for studying hard problems using methods similar to the message passing techniques that were discussed in Chapter 2. Although we concentrated on the symmetric case, cavity methods show promise for generalizing our methods to the un-symmetric case. As has been highlighted by John Hopfield, several key features of biological systems are not shared by physical systems. Although living entities follow the laws of physics and chemistry, the fact that organisms adapt and reproduce introduces an essential ingredient that is missing in the physical sciences. In order to extract information from networks many algorithm have been developed. In Chapter 5 we apply polynomial algorithms like minimum spanning tree in order to study and construct gene regulatory networks from experimental data. As future work we propose the use of algorithms like min-cut/max-flow and Dijkstra for understanding key properties of these networks.

Dynamics of Complex Systems Built as Coupled Physical, Communication and Decision Layers

PubMed Central

Kühnlenz, Florian; Nardelli, Pedro H. J.

2016-01-01

This paper proposes a simple model to capture the complexity of multilayer systems where their constituent layers affect, and are affected by, each other. The physical layer is a circuit composed by a power source and resistors in parallel. Every individual agent aims at maximizing its own delivered power by adding, removing or keeping the resistors it has; the delivered power is in turn a non-linear function that depends on the other agents’ behavior, its own internal state, its global state perception, the information received from its neighbors via the communication network and a randomized selfishness. We develop an agent-based simulation to analyze the effects of number of agents (system size), communication network topology, communication errors and the minimum power gain that triggers a behavioral change on the system dynamic. Our results show that a wave-like behavior at macro-level (caused by individual changes in the decision layer) can only emerge for a specific system size. The ratio between cooperators and defectors depends on the minimum gain assumed—lower minimal gains lead to less cooperation, and vice-versa. Different communication network topologies imply different levels of power utilization and fairness at the physical layer, and a certain level of error in the communication layer induces more cooperation. PMID:26730590

INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Synchronization in Complex Networks with Multiple Connections

NASA Astrophysics Data System (ADS)

Wu, Qing-Chu; Fu, Xin-Chu; Sun, Wei-Gang

2010-01-01

In this paper a class of networks with multiple connections are discussed. The multiple connections include two different types of links between nodes in complex networks. For this new model, we give a simple generating procedure. Furthermore, we investigate dynamical synchronization behavior in a delayed two-layer network, giving corresponding theoretical analysis and numerical examples.

An unsupervised method for quantifying the behavior of paired animals

NASA Astrophysics Data System (ADS)

Klibaite, Ugne; Berman, Gordon J.; Cande, Jessica; Stern, David L.; Shaevitz, Joshua W.

2017-02-01

Behaviors involving the interaction of multiple individuals are complex and frequently crucial for an animal’s survival. These interactions, ranging across sensory modalities, length scales, and time scales, are often subtle and difficult to characterize. Contextual effects on the frequency of behaviors become even more difficult to quantify when physical interaction between animals interferes with conventional data analysis, e.g. due to visual occlusion. We introduce a method for quantifying behavior in fruit fly interaction that combines high-throughput video acquisition and tracking of individuals with recent unsupervised methods for capturing an animal’s entire behavioral repertoire. We find behavioral differences between solitary flies and those paired with an individual of the opposite sex, identifying specific behaviors that are affected by social and spatial context. Our pipeline allows for a comprehensive description of the interaction between two individuals using unsupervised machine learning methods, and will be used to answer questions about the depth of complexity and variance in fruit fly courtship.

Scaling in geology: landforms and earthquakes.

PubMed Central

Turcotte, D L

1995-01-01

Landforms and earthquakes appear to be extremely complex; yet, there is order in the complexity. Both satisfy fractal statistics in a variety of ways. A basic question is whether the fractal behavior is due to scale invariance or is the signature of a broadly applicable class of physical processes. Both landscape evolution and regional seismicity appear to be examples of self-organized critical phenomena. A variety of statistical models have been proposed to model landforms, including diffusion-limited aggregation, self-avoiding percolation, and cellular automata. Many authors have studied the behavior of multiple slider-block models, both in terms of the rupture of a fault to generate an earthquake and in terms of the interactions between faults associated with regional seismicity. The slider-block models exhibit a remarkably rich spectrum of behavior; two slider blocks can exhibit low-order chaotic behavior. Large numbers of slider blocks clearly exhibit self-organized critical behavior. Images Fig. 6 PMID:11607562

Physical Chemistry of Nanomedicine: Understanding the Complex Behaviors of Nanoparticles in Vivo

NASA Astrophysics Data System (ADS)

Lane, Lucas A.; Qian, Ximei; Smith, Andrew M.; Nie, Shuming

2015-04-01

Nanomedicine is an interdisciplinary field of research at the interface of science, engineering, and medicine, with broad clinical applications ranging from molecular imaging to medical diagnostics, targeted therapy, and image-guided surgery. Despite major advances during the past 20 years, there are still major fundamental and technical barriers that need to be understood and overcome. In particular, the complex behaviors of nanoparticles under physiological conditions are poorly understood, and detailed kinetic and thermodynamic principles are still not available to guide the rational design and development of nanoparticle agents. Here we discuss the interactions of nanoparticles with proteins, cells, tissues, and organs from a quantitative physical chemistry point of view. We also discuss insights and strategies on how to minimize nonspecific protein binding, how to design multistage and activatable nanostructures for improved drug delivery, and how to use the enhanced permeability and retention effect to deliver imaging agents for image-guided cancer surgery.

Information geometric methods for complexity

NASA Astrophysics Data System (ADS)

Felice, Domenico; Cafaro, Carlo; Mancini, Stefano

2018-03-01

Research on the use of information geometry (IG) in modern physics has witnessed significant advances recently. In this review article, we report on the utilization of IG methods to define measures of complexity in both classical and, whenever available, quantum physical settings. A paradigmatic example of a dramatic change in complexity is given by phase transitions (PTs). Hence, we review both global and local aspects of PTs described in terms of the scalar curvature of the parameter manifold and the components of the metric tensor, respectively. We also report on the behavior of geodesic paths on the parameter manifold used to gain insight into the dynamics of PTs. Going further, we survey measures of complexity arising in the geometric framework. In particular, we quantify complexity of networks in terms of the Riemannian volume of the parameter space of a statistical manifold associated with a given network. We are also concerned with complexity measures that account for the interactions of a given number of parts of a system that cannot be described in terms of a smaller number of parts of the system. Finally, we investigate complexity measures of entropic motion on curved statistical manifolds that arise from a probabilistic description of physical systems in the presence of limited information. The Kullback-Leibler divergence, the distance to an exponential family and volumes of curved parameter manifolds, are examples of essential IG notions exploited in our discussion of complexity. We conclude by discussing strengths, limits, and possible future applications of IG methods to the physics of complexity.

Physics and Chemistry of Earth Materials

NASA Astrophysics Data System (ADS)

Navrotsky, Alexandra

1994-11-01

Stressing the fundamental solid state behavior of minerals, and emphasizing both theory and experiment, this text surveys the physics and chemistry of earth materials. The author begins with a systematic tour of crystal chemistry of both simple and complex structures (with completely new structural drawings) and discusses how to obtain structural and thermodynamic information experimentally. Dr. Navrotsky also reviews the quantitative concepts of chemical bonding--band theory, molecular orbit and ionic models. She then covers physical properties and relates microscopic features to macroscopic thermodynamic behavior and treats high pressure phase transitions, amorphous materials and solid state reactions. The author concludes with a look at the interface between mineral physics and materials science. Highly illustrated throughout, this book fills the gap between undergraduate texts and specialized review volumes and is appropriate for students and researchers in earth science and materials science.

A review of human factors challenges of complex adaptive systems: discovering and understanding chaos in human performance.

PubMed

Karwowski, Waldemar

2012-12-01

In this paper, the author explores a need for a greater understanding of the true nature of human-system interactions from the perspective of the theory of complex adaptive systems, including the essence of complexity, emergent properties of system behavior, nonlinear systems dynamics, and deterministic chaos. Human performance, more often than not, constitutes complex adaptive phenomena with emergent properties that exhibit nonlinear dynamical (chaotic) behaviors. The complexity challenges in the design and management of contemporary work systems, including service systems, are explored. Examples of selected applications of the concepts of nonlinear dynamics to the study of human physical performance are provided. Understanding and applications of the concepts of theory of complex adaptive and dynamical systems should significantly improve the effectiveness of human-centered design efforts of a large system of systems. Performance of many contemporary work systems and environments may be sensitive to the initial conditions and may exhibit dynamic nonlinear properties and chaotic system behaviors. Human-centered design of emergent human-system interactions requires application of the theories of nonlinear dynamics and complex adaptive system. The success of future human-systems integration efforts requires the fusion of paradigms, knowledge, design principles, and methodologies of human factors and ergonomics with those of the science of complex adaptive systems as well as modern systems engineering.

Education and Training in the Social, Behavioral, and Economic Sciences: A Plan of Action. A Report to the National Science Foundation.

ERIC Educational Resources Information Center

Levine, Felice J.; Abler, Ronald F.; Rosich, Katherine J.

2004-01-01

Over the last quarter of a century, the world has undergone rapid change. Almost every aspect of human life is more complex and interdependent, requiring knowledge of human and social systems as well as physical and biological systems. The social, behavioral, and economic (SBE) sciences contribute penetrating insights on such issues as the causes…

Quantum-like behavior without quantum physics I : Kinematics of neural-like systems.

PubMed

Selesnick, S A; Rawling, J P; Piccinini, Gualtiero

2017-09-01

Recently there has been much interest in the possible quantum-like behavior of the human brain in such functions as cognition, the mental lexicon, memory, etc., producing a vast literature. These studies are both empirical and theoretical, the tenets of the theory in question being mainly, and apparently inevitably, those of quantum physics itself, for lack of other arenas in which quantum-like properties are presumed to obtain. However, attempts to explain this behavior on the basis of actual quantum physics going on at the atomic or molecular level within some element of brain or neuronal anatomy (other than the ordinary quantum physics that underlies everything), do not seem to survive much scrutiny. Moreover, it has been found empirically that the usual physics-like Hilbert space model seems not to apply in detail to human cognition in the large. In this paper we lay the groundwork for a theory that might explain the provenance of quantum-like behavior in complex systems whose internal structure is essentially hidden or inaccessible. The approach is via the logic obeyed by these systems which is similar to, but not identical with, the logic obeyed by actual quantum systems. The results reveal certain effects in such systems which, though quantum-like, are not identical to the kinds of quantum effects found in physics. These effects increase with the size of the system.

Latent class analysis of lifestyle characteristics and health risk behaviors among college youth.

PubMed

Laska, Melissa Nelson; Pasch, Keryn E; Lust, Katherine; Story, Mary; Ehlinger, Ed

2009-12-01

Few studies have examined the context of a wide range of risk behaviors among emerging adults (ages 18-25 years), approximately half of whom in the USA enroll in post-secondary educational institutions. The objective of this research was to examine behavioral patterning in weight behaviors (diet and physical activity), substance use, sexual behavior, stress, and sleep among undergraduate students. Health survey data were collected among undergraduates attending a large, public US university (n = 2,026). Latent class analysis was used to identify homogeneous, mutually exclusive "classes" (patterns) of ten leading risk behaviors. Resulting classes differed for males and females. Female classes were defined as: (1) poor lifestyle (diet, physical activity, sleep), yet low-risk behaviors (e.g., smoking, binge drinking, sexual risk, drunk driving; 40.0% of females), (2) high risk (high substance use, intoxicated sex, drunk driving, poor diet, inadequate sleep) (24.3%), (3) moderate lifestyle, few risk behaviors (20.4%), (4) "health conscious" (favorable diet/physical activity with some unhealthy weight control; 15.4%). Male classes were: (1) poor lifestyle, low risk (with notably high stress, insufficient sleep, 9.2% of males), (2) high risk (33.6% of males, similar to class 2 in females), (3) moderate lifestyle, low risk (51.0%), and (4) "classic jocks" (high physical activity, binge drinking, 6.2%). To our knowledge, this is among the first research to examine complex lifestyle patterning among college youth, particularly with emphasis on the role of weight-related behaviors. These findings have important implications for targeting much needed health promotion strategies among emerging adults and college youth.

Links between quantum physics and thought.

PubMed

Robson, Barry

2009-01-01

Quantum mechanics (QM) provides a variety of ideas that can assist in developing Artificial Intelligence for healthcare, and opens the possibility of developing a unified system of Best Practice for inference that will embrace both QM and classical inference. Of particular interest is inference in the hyperbolic-complex plane, the counterpart of the normal i-complex plane of basic QM. There are two reasons. First, QM appears to rotate from i-complex Hilbert space to hyperbolic-complex descriptions when observations are made on wave functions as particles, yielding classical results, and classical laws of probability manipulation (e.g. the law of composition of probabilities) then hold, whereas in the i-complex plane they do not. Second, i-complex Hilbert space is not the whole story in physics. Hyperbolic complex planes arise in extension from the Dirac-Clifford calculus to particle physics, in relativistic correction thereby, and in regard to spinors and twisters. Generalization of these forms resemble grammatical constructions and promote the idea that probability-weighted algebraic elements can be used to hold dimensions of syntactic and semantic meaning. It is also starting to look as though when a solution is reached by an inference system in the hyperbolic-complex, the hyperbolic-imaginary values disappear, while conversely hyperbolic-imaginary values are associated with the un-queried state of a system and goal seeking behavior.

Modeling wind fields and fire propagation following bark beetle outbreaks in spatially-heterogeneous pinyon-juniper woodland fuel complexes

Treesearch

Rodman R. Linn; Carolyn H. Sieg; Chad M. Hoffman; Judith L. Winterkamp; Joel D. McMillin

2013-01-01

We used a physics-based model, HIGRAD/FIRETEC, to explore changes in within-stand wind behavior and fire propagation associated with three time periods in pinyon-juniper woodlands following a drought-induced bark beetle outbreak and subsequent tree mortality. Pinyon-juniper woodland fuel complexes are highly heterogeneous. Trees often are clumped, with sparse patches...

Self-affinity in the dengue fever time series

NASA Astrophysics Data System (ADS)

Azevedo, S. M.; Saba, H.; Miranda, J. G. V.; Filho, A. S. Nascimento; Moret, M. A.

2016-06-01

Dengue is a complex public health problem that is common in tropical and subtropical regions. This disease has risen substantially in the last three decades, and the physical symptoms depict the self-affine behavior of the occurrences of reported dengue cases in Bahia, Brazil. This study uses detrended fluctuation analysis (DFA) to verify the scale behavior in a time series of dengue cases and to evaluate the long-range correlations that are characterized by the power law α exponent for different cities in Bahia, Brazil. The scaling exponent (α) presents different long-range correlations, i.e. uncorrelated, anti-persistent, persistent and diffusive behaviors. The long-range correlations highlight the complex behavior of the time series of this disease. The findings show that there are two distinct types of scale behavior. In the first behavior, the time series presents a persistent α exponent for a one-month period. For large periods, the time series signal approaches subdiffusive behavior. The hypothesis of the long-range correlations in the time series of the occurrences of reported dengue cases was validated. The observed self-affinity is useful as a forecasting tool for future periods through extrapolation of the α exponent behavior. This complex system has a higher predictability in a relatively short time (approximately one month), and it suggests a new tool in epidemiological control strategies. However, predictions for large periods using DFA are hidden by the subdiffusive behavior.

Active control and sound synthesis--two different ways to investigate the influence of the modal parameters of a guitar on its sound.

PubMed

Benacchio, Simon; Mamou-Mani, Adrien; Chomette, Baptiste; Finel, Victor

2016-03-01

The vibrational behavior of musical instruments is usually studied using physical modeling and simulations. Recently, active control has proven its efficiency to experimentally modify the dynamical behavior of musical instruments. This approach could also be used as an experimental tool to systematically study fine physical phenomena. This paper proposes to use modal active control as an alternative to sound simulation to study the complex case of the coupling between classical guitar strings and soundboard. A comparison between modal active control and sound simulation investigates the advantages, the drawbacks, and the limits of these two approaches.

Chaotic itinerancy within the coupled dynamics between a physical body and neural oscillator networks

PubMed Central

Mori, Hiroki; Okuyama, Yuji; Asada, Minoru

2017-01-01

Chaotic itinerancy is a phenomenon in which the state of a nonlinear dynamical system spontaneously explores and attracts certain states in a state space. From this perspective, the diverse behavior of animals and its spontaneous transitions lead to a complex coupled dynamical system, including a physical body and a brain. Herein, a series of simulations using different types of non-linear oscillator networks (i.e., regular, small-world, scale-free, random) with a musculoskeletal model (i.e., a snake-like robot) as a physical body are conducted to understand how the chaotic itinerancy of bodily behavior emerges from the coupled dynamics between the body and the brain. A behavior analysis (behavior clustering) and network analysis for the classified behavior are then applied. The former consists of feature vector extraction from the motions and classification of the movement patterns that emerged from the coupled dynamics. The network structures behind the classified movement patterns are revealed by estimating the “information networks” different from the given non-linear oscillator networks based on the transfer entropy which finds the information flow among neurons. The experimental results show that: (1) the number of movement patterns and their duration depend on the sensor ratio to control the balance of strength between the body and the brain dynamics and on the type of the given non-linear oscillator networks; and (2) two kinds of information networks are found behind two kinds movement patterns with different durations by utilizing the complex network measures, clustering coefficient and the shortest path length with a negative and a positive relationship with the duration periods of movement patterns. The current results seem promising for a future extension of the method to a more complicated body and environment. Several requirements are also discussed. PMID:28796797

Chaotic itinerancy within the coupled dynamics between a physical body and neural oscillator networks.

PubMed

Park, Jihoon; Mori, Hiroki; Okuyama, Yuji; Asada, Minoru

2017-01-01

Chaotic itinerancy is a phenomenon in which the state of a nonlinear dynamical system spontaneously explores and attracts certain states in a state space. From this perspective, the diverse behavior of animals and its spontaneous transitions lead to a complex coupled dynamical system, including a physical body and a brain. Herein, a series of simulations using different types of non-linear oscillator networks (i.e., regular, small-world, scale-free, random) with a musculoskeletal model (i.e., a snake-like robot) as a physical body are conducted to understand how the chaotic itinerancy of bodily behavior emerges from the coupled dynamics between the body and the brain. A behavior analysis (behavior clustering) and network analysis for the classified behavior are then applied. The former consists of feature vector extraction from the motions and classification of the movement patterns that emerged from the coupled dynamics. The network structures behind the classified movement patterns are revealed by estimating the "information networks" different from the given non-linear oscillator networks based on the transfer entropy which finds the information flow among neurons. The experimental results show that: (1) the number of movement patterns and their duration depend on the sensor ratio to control the balance of strength between the body and the brain dynamics and on the type of the given non-linear oscillator networks; and (2) two kinds of information networks are found behind two kinds movement patterns with different durations by utilizing the complex network measures, clustering coefficient and the shortest path length with a negative and a positive relationship with the duration periods of movement patterns. The current results seem promising for a future extension of the method to a more complicated body and environment. Several requirements are also discussed.

Modified unified kinetic scheme for all flow regimes.

PubMed

Liu, Sha; Zhong, Chengwen

2012-06-01

A modified unified kinetic scheme for the prediction of fluid flow behaviors in all flow regimes is described. The time evolution of macrovariables at the cell interface is calculated with the idea that both free transport and collision mechanisms should be considered. The time evolution of macrovariables is obtained through the conservation constraints. The time evolution of local Maxwellian distribution is obtained directly through the one-to-one mapping from the evolution of macrovariables. These improvements provide more physical realities in flow behaviors and more accurate numerical results in all flow regimes especially in the complex transition flow regime. In addition, the improvement steps introduce no extra computational complexity.

Sensor Abstractions to Support Many-Robot Systems

DTIC Science & Technology

1993-04-01

the behaviors of the social insects: ants, bees, and termites ; the observed aggregate behaviors exhibit a greater complexity, while the individual...applicability -’f" togies from biology (hjrdirg, ec!"x’-oig, iiununc system and pheromone mechanisms) and physics (entropy, temperature, pressure...in [17-19]. Pheromones provide an important example of animals arranging their environment to, for example, help moths find mates, or to help a colony

Physically-Based Modelling and Real-Time Simulation of Fluids.

NASA Astrophysics Data System (ADS)

Chen, Jim Xiong

1995-01-01

Simulating physically realistic complex fluid behaviors presents an extremely challenging problem for computer graphics researchers. Such behaviors include the effects of driving boats through water, blending differently colored fluids, rain falling and flowing on a terrain, fluids interacting in a Distributed Interactive Simulation (DIS), etc. Such capabilities are useful in computer art, advertising, education, entertainment, and training. We present a new method for physically-based modeling and real-time simulation of fluids in computer graphics and dynamic virtual environments. By solving the 2D Navier -Stokes equations using a CFD method, we map the surface into 3D using the corresponding pressures in the fluid flow field. This achieves realistic real-time fluid surface behaviors by employing the physical governing laws of fluids but avoiding extensive 3D fluid dynamics computations. To complement the surface behaviors, we calculate fluid volume and external boundary changes separately to achieve full 3D general fluid flow. To simulate physical activities in a DIS, we introduce a mechanism which uses a uniform time scale proportional to the clock-time and variable time-slicing to synchronize physical models such as fluids in the networked environment. Our approach can simulate many different fluid behaviors by changing the internal or external boundary conditions. It can model different kinds of fluids by varying the Reynolds number. It can simulate objects moving or floating in fluids. It can also produce synchronized general fluid flows in a DIS. Our model can serve as a testbed to simulate many other fluid phenomena which have never been successfully modeled previously.

Trends in Bullying, Physical Fighting, and Weapon Carrying Among 6th- Through 10th-Grade Students From 1998 to 2010: Findings From a National Study

PubMed Central

Brooks-Russell, Ashley; Wang, Jing; Iannotti, Ronald J.

2014-01-01

Objectives. We examined trends from 1998 to 2010 in bullying, bullying victimization, physical fighting, and weapon carrying and variations by gender, grade level, and race/ethnicity among US adolescents. Methods. The Health Behavior in School-Aged Children surveys of nationally representative samples of students in grades 6 through 10 were completed in 1998 (n = 15 686), 2002 (n = 14 818), 2006 (n = 9229), and 2010 (n = 10 926). We assessed frequency of bullying behaviors, physical fighting, and weapon carrying as well as weapon type and subtypes of bullying. We conducted logistic regression analyses, accounting for the complex sampling design, to identify trends and variations by demographic factors. Results. Bullying perpetration, bullying victimization, and physical fighting declined from 1998 to 2010. Weapon carrying increased for White students only. Declines in bullying perpetration and victimization were greater for boys than for girls. Declines in bullying perpetration and physical fighting were greater for middle-school students than for high-school students. Conclusions. Declines in most violent behaviors are encouraging; however, lack of decline in weapon carrying merits further attention. PMID:24825213

A physical model for dementia

NASA Astrophysics Data System (ADS)

Sotolongo-Costa, O.; Gaggero-Sager, L. M.; Becker, J. T.; Maestu, F.; Sotolongo-Grau, O.

2017-04-01

Aging associated brain decline often result in some kind of dementia. Even when this is a complex brain disorder a physical model can be used in order to describe its general behavior. A probabilistic model for the development of dementia is obtained and fitted to some experimental data obtained from the Alzheimer's Disease Neuroimaging Initiative. It is explained how dementia appears as a consequence of aging and why it is irreversible.

A comprehensive approach to identify dominant controls of the behavior of a land surface-hydrology model across various hydroclimatic conditions

NASA Astrophysics Data System (ADS)

Haghnegahdar, Amin; Elshamy, Mohamed; Yassin, Fuad; Razavi, Saman; Wheater, Howard; Pietroniro, Al

2017-04-01

Complex physically-based environmental models are being increasingly used as the primary tool for watershed planning and management due to advances in computation power and data acquisition. Model sensitivity analysis plays a crucial role in understanding the behavior of these complex models and improving their performance. Due to the non-linearity and interactions within these complex models, Global sensitivity analysis (GSA) techniques should be adopted to provide a comprehensive understanding of model behavior and identify its dominant controls. In this study we adopt a multi-basin multi-criteria GSA approach to systematically assess the behavior of the Modélisation Environmentale-Surface et Hydrologie (MESH) across various hydroclimatic conditions in Canada including areas in the Great Lakes Basin, Mackenzie River Basin, and South Saskatchewan River Basin. MESH is a semi-distributed physically-based coupled land surface-hydrology modelling system developed by Environment and Climate Change Canada (ECCC) for various water resources management purposes in Canada. We use a novel method, called Variogram Analysis of Response Surfaces (VARS), to perform sensitivity analysis. VARS is a variogram-based GSA technique that can efficiently provide a spectrum of sensitivity information across a range of scales within the parameter space. We use multiple metrics to identify dominant controls of model response (e.g. streamflow) to model parameters under various conditions such as high flows, low flows, and flow volume. We also investigate the influence of initial conditions on model behavior as part of this study. Our preliminary results suggest that this type of GSA can significantly help with estimating model parameters, decreasing calibration computational burden, and reducing prediction uncertainty.

Childhood Obesity: Causes, Consequences, and Management.

PubMed

Gurnani, Muskaan; Birken, Catherine; Hamilton, Jill

2015-08-01

One-third of North American children are overweight or obese. Pathologic obesity accounts for only a small percentage of these cases. The vast majority are the result of a complex interaction of genetic and hormonal, nutritional, physical activity, and physical and social environmental factors. Obesity increases the risk for various cardiometabolic, pulmonary, and psychosocial complications for children, which often continues into adulthood. Multidisciplinary care, focusing on family-centered behavior change, is an evidence-based, essential part of the treatment, along with pharmacologic and surgical options for more complex cases. Prevention and early intervention strategies are key to reversing the obesity epidemic. Copyright © 2015 Elsevier Inc. All rights reserved.

Patterns of Chronic Conditions and Their Associations With Behaviors and Quality of Life, 2010

PubMed Central

Mitchell, Sandra A.; Thompson, William W.; Zack, Matthew M.; Reeve, Bryce B.; Cella, David; Smith, Ashley Wilder

2015-01-01

Introduction Co-occurring chronic health conditions elevate the risk of poor health outcomes such as death and disability, are associated with poor quality of life, and magnify the complexities of self-management, care coordination, and treatment planning. This study assessed patterns of both singular and multiple chronic conditions, behavioral risk factors, and quality of life in a population-based sample. Methods In a national survey, adults (n = 4,184) answered questions about the presence of 27 chronic conditions. We used latent class analysis to identify patterns of chronic conditions and to explore associations of latent class membership with sociodemographic characteristics, behavioral risk factors, and health. Results Latent class analyses indicated 4 morbidity profiles: a healthy class (class 1), a class with predominantly physical health conditions (class 2), a class with predominantly mental health conditions (class 3), and a class with both physical and mental health conditions (class 4). Class 4 respondents reported significantly worse physical health and well-being and more days of activity limitation than those in the other latent classes. Class 4 respondents were also more likely to be obese and sedentary, and those with predominantly mental health conditions were most likely to be current smokers. Conclusions Subgroups with distinct patterns of chronic conditions can provide direction for screening and surveillance, guideline development, and the delivery of complex care services. PMID:26679491

Measurement and Statistics of Application Business in Complex Internet

NASA Astrophysics Data System (ADS)

Wang, Lei; Li, Yang; Li, Yipeng; Wu, Shuhang; Song, Shiji; Ren, Yong

Owing to independent topologies and autonomic routing mechanism, the logical networks formed by Internet application business behavior cause the significant influence on the physical networks. In this paper, the backbone traffic of TUNET (Tsinghua University Networks) is measured, further more, the two most important application business: HTTP and P2P are analyzed at IP-packet level. It is shown that uplink HTTP and P2P packets behavior presents spatio-temporal power-law characteristics with exponents 1.25 and 1.53 respectively. Downlink HTTP packets behavior also presents power-law characteristics, but has more little exponents γ = 0.82 which differs from traditional complex networks research result. Moreover, downlink P2P packets distribution presents an approximate power-law which means that flow equilibrium profits little from distributed peer-to peer mechanism actually.

Monitoring a Complex Physical System using a Hybrid Dynamic Bayes Net

NASA Technical Reports Server (NTRS)

Lerner, Uri; Moses, Brooks; Scott, Maricia; McIlraith, Sheila; Keller, Daphne

2005-01-01

The Reverse Water Gas Shift system (RWGS) is a complex physical system designed to produce oxygen from the carbon dioxide atmosphere on Mars. If sent to Mars, it would operate without human supervision, thus requiring a reliable automated system for monitoring and control. The RWGS presents many challenges typical of real-world systems, including: noisy and biased sensors, nonlinear behavior, effects that are manifested over different time granularities, and unobservability of many important quantities. In this paper we model the RWGS using a hybrid (discrete/continuous) Dynamic Bayesian Network (DBN), where the state at each time slice contains 33 discrete and 184 continuous variables. We show how the system state can be tracked using probabilistic inference over the model. We discuss how to deal with the various challenges presented by the RWGS, providing a suite of techniques that are likely to be useful in a wide range of applications. In particular, we describe a general framework for dealing with nonlinear behavior using numerical integration techniques, extending the successful Unscented Filter. We also show how to use a fixed-point computation to deal with effects that develop at different time scales, specifically rapid changes occuring during slowly changing processes. We test our model using real data collected from the RWGS, demonstrating the feasibility of hybrid DBNs for monitoring complex real-world physical systems.

Characteristics of pattern formation and evolution in approximations of Physarum transport networks.

PubMed

Jones, Jeff

2010-01-01

Most studies of pattern formation place particular emphasis on its role in the development of complex multicellular body plans. In simpler organisms, however, pattern formation is intrinsic to growth and behavior. Inspired by one such organism, the true slime mold Physarum polycephalum, we present examples of complex emergent pattern formation and evolution formed by a population of simple particle-like agents. Using simple local behaviors based on chemotaxis, the mobile agent population spontaneously forms complex and dynamic transport networks. By adjusting simple model parameters, maps of characteristic patterning are obtained. Certain areas of the parameter mapping yield particularly complex long term behaviors, including the circular contraction of network lacunae and bifurcation of network paths to maintain network connectivity. We demonstrate the formation of irregular spots and labyrinthine and reticulated patterns by chemoattraction. Other Turing-like patterning schemes were obtained by using chemorepulsion behaviors, including the self-organization of regular periodic arrays of spots, and striped patterns. We show that complex pattern types can be produced without resorting to the hierarchical coupling of reaction-diffusion mechanisms. We also present network behaviors arising from simple pre-patterning cues, giving simple examples of how the emergent pattern formation processes evolve into networks with functional and quasi-physical properties including tensionlike effects, network minimization behavior, and repair to network damage. The results are interpreted in relation to classical theories of biological pattern formation in natural systems, and we suggest mechanisms by which emergent pattern formation processes may be used as a method for spatially represented unconventional computation.

The Napoleon Complex: When Shorter Men Take More.

PubMed

Knapen, Jill E P; Blaker, Nancy M; Van Vugt, Mark

2018-05-01

Inspired by an evolutionary psychological perspective on the Napoleon complex, we hypothesized that shorter males are more likely to show indirect aggression in resource competitions with taller males. Three studies provide support for our interpretation of the Napoleon complex. Our pilot study shows that men (but not women) keep more resources for themselves when they feel small. When paired with a taller male opponent (Study 1), shorter men keep more resources to themselves in a game in which they have all the power (dictator game) versus a game in which the opponent also has some power (ultimatum game). Furthermore, shorter men are not more likely to show direct, physical aggression toward a taller opponent (Study 2). As predicted by the Napoleon complex, we conclude that (relatively) shorter men show greater behavioral flexibility in securing resources when presented with cues that they are physically less competitive. Theoretical and practical implications are discussed.

Latent Class Analysis of Lifestyle Characteristics and Health Risk Behaviors among College Youth

PubMed Central

Pasch, Keryn E.; Lust, Katherine; Story, Mary; Ehlinger, Ed

2010-01-01

Few studies have examined the context of a wide range of risk behaviors among emerging adults (ages 18–25 years), approximately half of whom in the USA enroll in post-secondary educational institutions. The objective of this research was to examine behavioral patterning in weight behaviors (diet and physical activity), substance use, sexual behavior, stress, and sleep among undergraduate students. Health survey data were collected among undergraduates attending a large, public US university (n=2,026). Latent class analysis was used to identify homogeneous, mutually exclusive “classes” (patterns) of ten leading risk behaviors. Resulting classes differed for males and females. Female classes were defined as: (1) poor lifestyle (diet, physical activity, sleep), yet low-risk behaviors (e.g., smoking, binge drinking, sexual risk, drunk driving; 40.0% of females), (2) high risk (high substance use, intoxicated sex, drunk driving, poor diet, inadequate sleep) (24.3%), (3) moderate lifestyle, few risk behaviors (20.4%), (4) “health conscious” (favorable diet/physical activity with some unhealthy weight control; 15.4%). Male classes were: (1) poor lifestyle, low risk (with notably high stress, insufficient sleep, 9.2% of males), (2) high risk (33.6% of males, similar to class 2 in females), (3) moderate lifestyle, low risk (51.0%), and (4) “classic jocks” (high physical activity, binge drinking, 6.2%). To our knowledge, this is among the first research to examine complex lifestyle patterning among college youth, particularly with emphasis on the role of weight-related behaviors. These findings have important implications for targeting much needed health promotion strategies among emerging adults and college youth. PMID:19499339

Exploring staff perceptions on the role of physical environment in dementia care setting.

PubMed

Lee, Sook Y; Chaudhury, Habib; Hung, Lillian

2016-07-01

This study explored staff perceptions of the role of physical environment in dementia care facilities in affecting resident's behaviors and staff care practice. We conducted focus groups with staff (n = 15) in two purposely selected care facilities in Vancouver, Canada. Focus group participants included nurses, care aides, recreation staff, administrative staff, and family. Data analysis revealed two themes: (a) a supportive physical environment contributes positively to both quality of staff care interaction and residents' quality of life and (b) an unsupportive physical environment contributes negatively to residents' quality of life and thereby makes the work of staff more challenging. The staff participants collectively viewed that comfort, familiarity, and an organized space were important therapeutic resources for supporting the well-being of residents. Certain behaviors of residents were influenced by poor environmental factors, including stimulation overload, safety risks, wayfinding challenge, and rushed care This study demonstrates the complex interrelationships among the dementia care setting's physical environment, staff experiences, and residents' quality of life. © The Author(s) 2014.

Exploring relationship between face-to-face interaction and team performance using wearable sensor badges.

PubMed

Watanabe, Jun-ichiro; Ishibashi, Nozomu; Yano, Kazuo

2014-01-01

Quantitative analyses of human-generated data collected in various fields have uncovered many patterns of complex human behaviors. However, thus far the quantitative evaluation of the relationship between the physical behaviors of employees and their performance has been inadequate. Here, we present findings demonstrating the significant relationship between the physical behaviors of employees and their performance via experiments we conducted in inbound call centers while the employees wore sensor badges. There were two main findings. First, we found that face-to-face interaction among telecommunicators and the frequency of their bodily movements caused by the face-to-face interaction had a significant correlation with the entire call center performance, which we measured as "Calls per Hour." Second, our trial to activate face-to-face interaction on the basis of data collected by the wearable sensor badges the employees wore significantly increased their performance. These results demonstrate quantitatively that human-human interaction in the physical world plays an important role in team performance.

Exploring Relationship between Face-to-Face Interaction and Team Performance Using Wearable Sensor Badges

PubMed Central

Watanabe, Jun-ichiro; Ishibashi, Nozomu; Yano, Kazuo

2014-01-01

Quantitative analyses of human-generated data collected in various fields have uncovered many patterns of complex human behaviors. However, thus far the quantitative evaluation of the relationship between the physical behaviors of employees and their performance has been inadequate. Here, we present findings demonstrating the significant relationship between the physical behaviors of employees and their performance via experiments we conducted in inbound call centers while the employees wore sensor badges. There were two main findings. First, we found that face-to-face interaction among telecommunicators and the frequency of their bodily movements caused by the face-to-face interaction had a significant correlation with the entire call center performance, which we measured as “Calls per Hour.” Second, our trial to activate face-to-face interaction on the basis of data collected by the wearable sensor badges the employees wore significantly increased their performance. These results demonstrate quantitatively that human-human interaction in the physical world plays an important role in team performance. PMID:25501748

Maternal factors predicting cognitive and behavioral characteristics of children with fetal alcohol spectrum disorders.

PubMed

May, Philip A; Tabachnick, Barbara G; Gossage, J Phillip; Kalberg, Wendy O; Marais, Anna-Susan; Robinson, Luther K; Manning, Melanie A; Blankenship, Jason; Buckley, David; Hoyme, H Eugene; Adnams, Colleen M

2013-06-01

To provide an analysis of multiple predictors of cognitive and behavioral traits for children with fetal alcohol spectrum disorders (FASDs). Multivariate correlation techniques were used with maternal and child data from epidemiologic studies in a community in South Africa. Data on 561 first-grade children with fetal alcohol syndrome (FAS), partial FAS (PFAS), and not FASD and their mothers were analyzed by grouping 19 maternal variables into categories (physical, demographic, childbearing, and drinking) and used in structural equation models (SEMs) to assess correlates of child intelligence (verbal and nonverbal) and behavior. A first SEM using only 7 maternal alcohol use variables to predict cognitive/behavioral traits was statistically significant (B = 3.10, p < .05) but explained only 17.3% of the variance. The second model incorporated multiple maternal variables and was statistically significant explaining 55.3% of the variance. Significantly correlated with low intelligence and problem behavior were demographic (B = 3.83, p < .05) (low maternal education, low socioeconomic status [SES], and rural residence) and maternal physical characteristics (B = 2.70, p < .05) (short stature, small head circumference, and low weight). Childbearing history and alcohol use composites were not statistically significant in the final complex model and were overpowered by SES and maternal physical traits. Although other analytic techniques have amply demonstrated the negative effects of maternal drinking on intelligence and behavior, this highly controlled analysis of multiple maternal influences reveals that maternal demographics and physical traits make a significant enabling or disabling contribution to child functioning in FASD.

A study of complex scaling transformation using the Wigner representation of wavefunctions.

PubMed

Kaprálová-Ždánská, Petra Ruth

2011-05-28

The complex scaling operator exp(-θ ̂x̂p/ℏ), being a foundation of the complex scaling method for resonances, is studied in the Wigner phase-space representation. It is shown that the complex scaling operator behaves similarly to the squeezing operator, rotating and amplifying Wigner quasi-probability distributions of the respective wavefunctions. It is disclosed that the distorting effect of the complex scaling transformation is correlated with increased numerical errors of computed resonance energies and widths. The behavior of the numerical error is demonstrated for a computation of CO(2+) vibronic resonances. © 2011 American Institute of Physics

Measuring fish and their physical habitats: Versatile 2D and 3D video techniques with user-friendly software

USGS Publications Warehouse

Neuswanger, Jason R.; Wipfli, Mark S.; Rosenberger, Amanda E.; Hughes, Nicholas F.

2017-01-01

Applications of video in fisheries research range from simple biodiversity surveys to three-dimensional (3D) measurement of complex swimming, schooling, feeding, and territorial behaviors. However, researchers lack a transparently developed, easy-to-use, general purpose tool for 3D video measurement and event logging. Thus, we developed a new measurement system, with freely available, user-friendly software, easily obtained hardware, and flexible underlying mathematical methods capable of high precision and accuracy. The software, VidSync, allows users to efficiently record, organize, and navigate complex 2D or 3D measurements of fish and their physical habitats. Laboratory tests showed submillimetre accuracy in length measurements of 50.8 mm targets at close range, with increasing errors (mostly <1%) at longer range and for longer targets. A field test on juvenile Chinook salmon (Oncorhynchus tshawytscha) feeding behavior in Alaska streams found that individuals within aggregations avoided the immediate proximity of their competitors, out to a distance of 1.0 to 2.9 body lengths. This system makes 3D video measurement a practical tool for laboratory and field studies of aquatic or terrestrial animal behavior and ecology.

On Chaotic and Hyperchaotic Complex Nonlinear Dynamical Systems

NASA Astrophysics Data System (ADS)

Mahmoud, Gamal M.

Dynamical systems described by real and complex variables are currently one of the most popular areas of scientific research. These systems play an important role in several fields of physics, engineering, and computer sciences, for example, laser systems, control (or chaos suppression), secure communications, and information science. Dynamical basic properties, chaos (hyperchaos) synchronization, chaos control, and generating hyperchaotic behavior of these systems are briefly summarized. The main advantage of introducing complex variables is the reduction of phase space dimensions by a half. They are also used to describe and simulate the physics of detuned laser and thermal convection of liquid flows, where the electric field and the atomic polarization amplitudes are both complex. Clearly, if the variables of the system are complex the equations involve twice as many variables and control parameters, thus making it that much harder for a hostile agent to intercept and decipher the coded message. Chaotic and hyperchaotic complex systems are stated as examples. Finally there are many open problems in the study of chaotic and hyperchaotic complex nonlinear dynamical systems, which need further investigations. Some of these open problems are given.

Simulating Life

ERIC Educational Resources Information Center

Sinclair, Michael; Dauerty, Helene; Alber, Mark

2016-01-01

Biomodeling is the study of the structures and behaviors of interacting biological entities such as molecules, cells, or organisms. While physical and chemical processes give rise to various spatial and temporal structures, even the simplest biological phenomenon is infinitely more complex (Kling 2004). Over the past decade, much of biomodeling…

Measurement of Sticky Point Temperature of Coffee Powder with a Rheometer

USDA-ARS?s Scientific Manuscript database

Sticky point temperature (Ts) measurement for hygroscopic food and biomaterial powders is traditionally performed with complex glass instruments. This property is used to characterize material stickiness, which substantially affects the flow and physical behavior of powders. In this research study w...

Pubertal Timing and Adolescent Sexual Behavior in Girls

ERIC Educational Resources Information Center

Moore, Sarah R.; Harden, K. Paige; Mendle, Jane

2014-01-01

Girls who experience earlier pubertal timing relative to peers also exhibit earlier timing of sexual intercourse and more unstable sexual relationships. Although pubertal development initiates feelings of physical desire, the transition into romantic and sexual relationships involves complex biological and social processes contributing both to…

Physical properties of mixed dairy food proteins

USDA-ARS?s Scientific Manuscript database

Mixed food protein gels are complex systems, which changes functional behaviors such as gelling properties and viscosity depending on the miscibility of the proteins. We have noted that differences in co-solubility of mixed proteins created unique network structures and gel properties. The effects o...

Migration of cells in a social context

PubMed Central

Vedel, Søren; Tay, Savaş; Johnston, Darius M.; Bruus, Henrik; Quake, Stephen R.

2013-01-01

In multicellular organisms and complex ecosystems, cells migrate in a social context. Whereas this is essential for the basic processes of life, the influence of neighboring cells on the individual remains poorly understood. Previous work on isolated cells has observed a stereotypical migratory behavior characterized by short-time directional persistence with long-time random movement. We discovered a much richer dynamic in the social context, with significant variations in directionality, displacement, and speed, which are all modulated by local cell density. We developed a mathematical model based on the experimentally identified “cellular traffic rules” and basic physics that revealed that these emergent behaviors are caused by the interplay of single-cell properties and intercellular interactions, the latter being dominated by a pseudopod formation bias mediated by secreted chemicals and pseudopod collapse following collisions. The model demonstrates how aspects of complex biology can be explained by simple rules of physics and constitutes a rapid test bed for future studies of collective migration of individual cells. PMID:23251032

Migration of cells in a social context.

PubMed

Vedel, Søren; Tay, Savaş; Johnston, Darius M; Bruus, Henrik; Quake, Stephen R

2013-01-02

In multicellular organisms and complex ecosystems, cells migrate in a social context. Whereas this is essential for the basic processes of life, the influence of neighboring cells on the individual remains poorly understood. Previous work on isolated cells has observed a stereotypical migratory behavior characterized by short-time directional persistence with long-time random movement. We discovered a much richer dynamic in the social context, with significant variations in directionality, displacement, and speed, which are all modulated by local cell density. We developed a mathematical model based on the experimentally identified "cellular traffic rules" and basic physics that revealed that these emergent behaviors are caused by the interplay of single-cell properties and intercellular interactions, the latter being dominated by a pseudopod formation bias mediated by secreted chemicals and pseudopod collapse following collisions. The model demonstrates how aspects of complex biology can be explained by simple rules of physics and constitutes a rapid test bed for future studies of collective migration of individual cells.

1998 Complex Systems Summer School

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-12-15

For the past eleven years a group of institutes, centers, and universities throughout the country have sponsored a summer school in Santa Fe, New Mexico as part of an interdisciplinary effort to promote the understanding of complex systems. The goal of these summer schools is to provide graduate students, postdoctoral fellows and active research scientists with an introduction to the study of complex behavior in mathematical, physical, and living systems. The Center for Nonlinear Studies supported the eleventh in this series of highly successful schools in Santa Fe in June, 1998.

Network Analysis of Rat Spatial Cognition: Behaviorally-Established Symmetry in a Physically Asymmetrical Environment

PubMed Central

Eilam, David; Portugali, Juval; Blumenfeld-Lieberthal, Efrat

2012-01-01

Background We set out to solve two inherent problems in the study of animal spatial cognition (i) What is a “place”?; and (ii) whether behaviors that are not revealed as differing by one methodology could be revealed as different when analyzed using a different approach. Methodology We applied network analysis to scrutinize spatial behavior of rats tested in either a symmetrical or asymmetrical layout of 4, 8, or 12 objects placed along the perimeter of a round arena. We considered locations as the units of the network (nodes), and passes between locations as the links within the network. Principal Findings While there were only minor activity differences between rats tested in the symmetrical or asymmetrical object layouts, network analysis revealed substantial differences. Viewing ‘location’ as a cluster of stopping coordinates, the key locations (large clusters of stopping coordinates) were at the objects in both layouts with 4 objects. However, in the asymmetrical layout with 4 objects, additional key locations were spaced by the rats between the objects, forming symmetry among the key locations. It was as if the rats had behaviorally imposed symmetry on the physically asymmetrical environment. Based on a previous finding that wayfinding is easier in symmetrical environments, we suggest that when the physical attributes of the environment were not symmetrical, the rats established a symmetric layout of key locations, thereby acquiring a more legible environment despite its complex physical structure. Conclusions and Significance The present study adds a behavioral definition for “location”, a term that so far has been mostly discussed according to its physical attributes or neurobiological correlates (e.g. - place and grid neurons). Moreover, network analysis enabled the assessment of the importance of a location, even when that location did not display any distinctive physical properties. PMID:22815808

ADAPT: The Agent Development and Prototyping Testbed.

PubMed

Shoulson, Alexander; Marshak, Nathan; Kapadia, Mubbasir; Badler, Norman I

2014-07-01

We present ADAPT, a flexible platform for designing and authoring functional, purposeful human characters in a rich virtual environment. Our framework incorporates character animation, navigation, and behavior with modular interchangeable components to produce narrative scenes. The animation system provides locomotion, reaching, gaze tracking, gesturing, sitting, and reactions to external physical forces, and can easily be extended with more functionality due to a decoupled, modular structure. The navigation component allows characters to maneuver through a complex environment with predictive steering for dynamic obstacle avoidance. Finally, our behavior framework allows a user to fully leverage a character's animation and navigation capabilities when authoring both individual decision-making and complex interactions between actors using a centralized, event-driven model.

The effect of a furnished individual hutch pre-weaning on calf behavior, response to novelty, and growth.

PubMed

Pempek, J A; Eastridge, M L; Proudfoot, K L

2017-06-01

Housing preweaned dairy calves in individual outdoor hutches is common in North America. However, this type of housing lacks stimulation and minimizes calves' ability to express natural behavior. Providing a social companion has been shown to stimulate natural behavior and promote growth, but no research has assessed the effect of providing physical enrichment items to calves pre-weaning. The objective of this study was to determine calf use of physical items added to an individual hutch, and if providing these items affected growth, behavior (e.g., locomotor play and sucking on pen fixtures), and response to novelty after weaning. At birth, Jersey heifer calves were allocated to 1 of 2 types of hutches: furnished (n = 9 calves) or standard (n = 10 calves). Calves were housed in individual hutches on loose gravel and bedded with straw. The outdoor enclosure of furnished hutches contained 2 artificial teats, a stationary brush, a calf "lollie," and a rubber chain link for calves to manipulate. Calves were video-recorded continuously between 0800 and 2000 h twice weekly at 1, 3, 5, and 7 wk of age; behavioral data were collected using the Noldus Observer software program (Noldus Inc., Wageningen, the Netherlands). At 63 d of age (after weaning), calf response to social and environmental novelty was tested. Starter consumption was measured daily, and calves were weighed at birth and weekly thereafter. Pre-weaning behavioral data were not normally distributed, so raw data were square-root-transformed before analysis. Calves used all of the items depending on the time of day, but they spent the most time using the brush. Calves housed in furnished hutches spent almost 50% more time engaged in locomotor play, but they spent the same amount of time sucking pen fixtures as calves housed in standard hutches. We observed no effect of treatment on growth, starter intake, or behavioral response to social and environmental novelty after weaning. Results suggest that providing some physical complexity to a standard hutch has some benefits for young calves, but further research is encouraged to determine the long-term effects of physical and social complexity for young dairy heifer calves. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Preparation, physicochemical characterization and release behavior of the inclusion complex of trans-anethole and β-cyclodextrin.

PubMed

Zhang, Wenwen; Li, Xinying; Yu, Taocheng; Yuan, Lun; Rao, Gang; Li, Defu; Mu, Changdao

2015-08-01

Trans-anethole (AT) has a variety of antimicrobial properties and is widely used as food functional ingredient. However, the applications of AT are limited due to its low water solubility, strong odor and low physicochemical stability. Therefore, the aim of this work was to encapsulate AT with β-cyclodextrin (β-CD) for obtaining inclusion complex by co-precipitation method. The measurements effectively confirmed the formation of inclusion complex between AT and β-CD. The results showed that the inclusion complex presented new solid crystalline phases and was more thermally stable than the physical mixture and β-CD. The phase solubility study showed that the aqueous solubility of AT was increased by being included in β-CD. The calculated stability constant of inclusion complex was 1195M -1 , indicating the strong interaction between AT and β-CD. Furthermore, the release study suggested that β-CD provided the protection for AT against evaporation. The release behavior of AT from the inclusion complex was controlled. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differential Multiscale Modeling of Chemically Complex Materials under Heavy Deformation: Biological, Bioinspired and Synthetic Hierarchical Materials

DTIC Science & Technology

2010-06-01

Buehler, “Meso- Origami : Folding Multilayer Graphene Sheets”, Applied Physics Letters, Vol. 95, paper #: 123121, 2009 D. Sen and M.J. Buehler, “Size and... geometry effects on flow stress in bioinspired de novo metal-matrix nanocomposites”, Advanced Engineering Materials, Vol. 11(10), pp. 774-781, 2009...behavior is recovered. Second, a subset of all geometries shows the inverse banana curve behavior. Interestingly, only 2% of all structures give the

Understanding gender norms, nutrition, and physical activity in adolescent girls: a scoping review.

PubMed

Spencer, Rebecca A; Rehman, Laurene; Kirk, Sara F L

2015-01-24

Public health is currently focused on childhood obesity, and the associated behaviors of physical activity and nutrition. Canadian youth are insufficiently active and do not meet nutritional guidelines. This is of particular concern for adolescent girls, as they are less active than boys, become less active as they age, and engage in unhealthy weight control behaviors. The purpose of this review is to determine what is known from the existing literature about how gender norms are understood in relation to the health-related behaviors of PA and nutrition in young girls. This scoping review follows the framework of Arksey and O'Malley, involving defining a research question, study identification and selection, charting, interpretation, summarizing, and reporting. In total, 28 documents are reviewed, and characteristics are summarized quantitatively and qualitatively. Five major themes are identified: (1) Girls' relationships with PA are complex and require negotiating gender roles, (2) the literature focuses on dieting rather than nutrition, (3) appearance and perceptions influence behaviors, (4) "body" focused discourse is significant to girls' experiences, and (5) social influences, institutions, and environments are influential and may offer opportunity for future research and action. Gaps in the literature are identified and discussed. It is concluded that young girls' activity and nutrition is affected by gender norms and feminine ideals through complex negotiations, perceptions, body-centered discourse, and societal influences.

Tensegrity II. How structural networks influence cellular information processing networks

NASA Technical Reports Server (NTRS)

Ingber, Donald E.

2003-01-01

The major challenge in biology today is biocomplexity: the need to explain how cell and tissue behaviors emerge from collective interactions within complex molecular networks. Part I of this two-part article, described a mechanical model of cell structure based on tensegrity architecture that explains how the mechanical behavior of the cell emerges from physical interactions among the different molecular filament systems that form the cytoskeleton. Recent work shows that the cytoskeleton also orients much of the cell's metabolic and signal transduction machinery and that mechanical distortion of cells and the cytoskeleton through cell surface integrin receptors can profoundly affect cell behavior. In particular, gradual variations in this single physical control parameter (cell shape distortion) can switch cells between distinct gene programs (e.g. growth, differentiation and apoptosis), and this process can be viewed as a biological phase transition. Part II of this article covers how combined use of tensegrity and solid-state mechanochemistry by cells may mediate mechanotransduction and facilitate integration of chemical and physical signals that are responsible for control of cell behavior. In addition, it examines how cell structural networks affect gene and protein signaling networks to produce characteristic phenotypes and cell fate transitions during tissue development.

A system dynamics optimization framework to achieve population desired of average weight target

NASA Astrophysics Data System (ADS)

Abidin, Norhaslinda Zainal; Zulkepli, Jafri Haji; Zaibidi, Nerda Zura

2017-11-01

Obesity is becoming a serious problem in Malaysia as it has been rated as the highest among Asian countries. The aim of the paper is to propose a system dynamics (SD) optimization framework to achieve population desired weight target based on the changes in physical activity behavior and its association to weight and obesity. The system dynamics approach of stocks and flows diagram was used to quantitatively model the impact of both behavior on the population's weight and obesity trends. This work seems to bring this idea together and highlighting the interdependence of the various aspects of eating and physical activity behavior on the complex of human weight regulation system. The model was used as an experimentation vehicle to investigate the impacts of changes in physical activity on weight and prevalence of obesity implications. This framework paper provides evidence on the usefulness of SD optimization as a strategic decision making approach to assist in decision making related to obesity prevention. SD applied in this research is relatively new in Malaysia and has a high potential to apply to any feedback models that address the behavior cause to obesity.

Mechanical design of DNA nanostructures

NASA Astrophysics Data System (ADS)

Castro, Carlos E.; Su, Hai-Jun; Marras, Alexander E.; Zhou, Lifeng; Johnson, Joshua

2015-03-01

Structural DNA nanotechnology is a rapidly emerging field that has demonstrated great potential for applications such as single molecule sensing, drug delivery, and templating molecular components. As the applications of DNA nanotechnology expand, a consideration of their mechanical behavior is becoming essential to understand how these structures will respond to physical interactions. This review considers three major avenues of recent progress in this area: (1) measuring and designing mechanical properties of DNA nanostructures, (2) designing complex nanostructures based on imposed mechanical stresses, and (3) designing and controlling structurally dynamic nanostructures. This work has laid the foundation for mechanically active nanomachines that can generate, transmit, and respond to physical cues in molecular systems.Structural DNA nanotechnology is a rapidly emerging field that has demonstrated great potential for applications such as single molecule sensing, drug delivery, and templating molecular components. As the applications of DNA nanotechnology expand, a consideration of their mechanical behavior is becoming essential to understand how these structures will respond to physical interactions. This review considers three major avenues of recent progress in this area: (1) measuring and designing mechanical properties of DNA nanostructures, (2) designing complex nanostructures based on imposed mechanical stresses, and (3) designing and controlling structurally dynamic nanostructures. This work has laid the foundation for mechanically active nanomachines that can generate, transmit, and respond to physical cues in molecular systems. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07153k

Effects of a brief, pedometer-based behavioral intervention for individuals with COPD during inpatient pulmonary rehabilitation on 6-week and 6-month objectively measured physical activity: study protocol for a randomized controlled trial.

PubMed

Geidl, Wolfgang; Semrau, Jana; Streber, René; Lehbert, Nicola; Wingart, Silke; Tallner, Alexander; Wittmann, Michael; Wagner, Rupert; Schultz, Konrad; Pfeifer, Klaus

2017-08-29

Pulmonary rehabilitation programs often fail to substantially enhance long-term physical activity in patients with chronic obstructive pulmonary disease (COPD). The reasons for successful physical activity changes in patients with COPD are not well understood. The need to better understand the determinants of physical activity in patients with COPD and effective rehabilitation strategies to improve physical activity is evident. The STAR study (Stay Active after Rehabilitation) investigates, in a randomized controlled trial, the additional effect of a pedometer-based behavior-change intervention during inpatient pulmonary rehabilitation on objectively measured physical activity 6 weeks and 6 months post rehabilitation. The intervention uses the behavior-change techniques (1) instruction on how, where and when to perform the behavior, (2) prompt goal setting for physical activity, (3) prompt self-monitoring of behavior, and (4) feedback on behavior. The primary outcome of physical activity will be measured using a physical activity monitor (Actigraph wGT3X-BT) for a period of 7 days, firstly 2 weeks before rehabilitation begins (t0) as well as 6 weeks and 6 months after rehabilitation (t3, t4). Additionally, to predict physical activity progression after rehabilitation, a complex personal diagnostics battery, including questionnaires as well as functional assessments, is to be carried out at the start and end of rehabilitation (t1, t2). This battery is based on the foundational ideas of the Physical Activity-Related health Competence model. Five hundred and two patients with COPD, aged 18 years or older and admitted for an approved pulmonary rehabilitation, will be enrolled in the STAR study. The STAR study is designed as a randomized controlled trial to gain a better understanding of the personal determinants of physical activity in patients with COPD and to evaluate a pedometer-based physical activity-change intervention in the context of inpatient pulmonary rehabilitation. The results enable the future identification of patients with COPD who will find it difficult to engage in long-term physical activity after rehabilitation. Based on this, intervention strategies to promote physical activity in the content of pulmonary rehabilitation can be optimized. Clinicaltrials.gov, ID: NCT02966561 . Registered retrospectively after the start of the recruitment in June 2016 on 22 November 2016. All protocol modifications will be registered in the trial registry.

Intimate Violence as It Relates to Risky Sexual Behavior Among At-Risk Females.

PubMed

Hill, Danielle C; Stein, L A R; Rossi, Joseph S; Magill, Molly; Clarke, Jennifer G

2017-10-05

Rates of sexually transmitted infections (STIs) among adolescents are on the rise. The majority of adolescents who contract STIs do so through risky sexual behavior. Previous literature has identified multiple correlates of risky sexual behaviors among adolescents, including physical and sexual victimization, mental health concerns, and substance use. Few studies, however, have examined these relationships together in a comprehensive model. The primary purpose of this study was to examine whether relationship violence was related to risky sexual behavior, and whether mental health symptoms and substance use mediated this relationship. A cross-sectional design was used, and adolescent females (N = 179), recruited from social service agencies, were 18.9 years old on average and were 37.2% White, 19.3% Black, 37.9% multiracial, and 5.6% other. Regression results revealed that females who were physically assaulted and sexually victimized by their intimate partners did engage in more sex without condoms. Mediational analyses indicated that PTSD symptoms significantly influenced the relationship between (1) physical assault and risky sexual behavior and (2) sexual victimization and risky sexual behavior. Contrary to expectations, PTSD may act to reduce risk perhaps by reducing interest in sex. It is important to address victimization, PTSD, and sexual risk in young women. More work is needed to understand these complex relationships using longitudinal designs. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Maternal Factors Predicting Cognitive and Behavioral Characteristics of Children with Fetal Alcohol Spectrum Disorders

PubMed Central

May, Philip A.; Tabachnick, Barbara G.; Gossage, J. Phillip; Kalberg, Wendy O.; Marais, Anna-Susan; Robinson, Luther K.; Manning, Melanie A.; Blankenship, Jason; Buckley, David; Hoyme, H. Eugene; Adnams, Colleen M.

2013-01-01

Objective To provide an analysis of multiple predictors of cognitive and behavioral traits for children with fetal alcohol spectrum disorders (FASD). Method Multivariate correlation techniques were employed with maternal and child data from epidemiologic studies in a community in South Africa. Data on 561 first grade children with fetal alcohol syndrome (FAS), partial FAS (PFAS), and not FASD and their mothers were analyzed by grouping 19 maternal variables into categories (physical, demographic, childbearing, and drinking) and employed in structural equation models (SEM) to assess correlates of child intelligence (verbal and non-verbal) and behavior. Results A first SEM utilizing only seven maternal alcohol use variables to predict cognitive/behavioral traits was statistically significant (B = 3.10, p < .05), but explained only 17.3% of the variance. The second model incorporated multiple maternal variables and was statistically significant explaining 55.3% of the variance. Significantly correlated with low intelligence and problem behavior were demographic (B = 3.83, p < .05) (low maternal education, low socioeconomic status (SES), and rural residence) and maternal physical characteristics (B = 2.70, p < .05) (short stature, small head circumference, and low weight). Childbearing history and alcohol use composites were not statistically significant in the final complex model, and were overpowered by SES and maternal physical traits. Conclusions While other analytic techniques have amply demonstrated the negative effects of maternal drinking on intelligence and behavior, this highly-controlled analysis of multiple maternal influences reveals that maternal demographics and physical traits make a significant enabling or disabling contribution to child functioning in FASD. PMID:23751886

The Noticing of Physical Education Teachers: A Comparison of Groups with Different Expertise

ERIC Educational Resources Information Center

Reuker, Sabine

2017-01-01

Background: Teachers' important diagnostic abilities include noticing and interpreting students' behaviors and learning processes. By focusing on noticing, I refer to the theoretical framework of professional vision. Professional vision includes the ability to notice what is occurring in complex classroom situations (selective attention) and the…

Data management in the mission data system

NASA Technical Reports Server (NTRS)

Wagner, David A.

2005-01-01

As spacecraft evolve from simple embedded devices to become more sophisticated computing platforms with complex behaviors it is increasingly necessary to model and manage the flow of data, and to provide uniform models for managing data that promote adaptability, yet pay heed to the physical limitations of the embedded and space environments.

A Qualitative Examination of Health Barriers and Facilitators Among African American Mothers in a Subsidized Housing Community.

PubMed

Cotter, Elizabeth W; Hamilton, Natia S; Kelly, Nichole R; Harney, Megan B; Greene, LaShaun; White, Kelly A; Mazzeo, Suzanne E

2016-09-01

Although African American families are at particular risk for obesity and its associated health comorbidities, few interventions have directly targeted low-income members of this group living in subsidized public housing. Using a consensual qualitative research approach, we conducted 11 interviews with African American mothers living in two public housing communities to enhance understanding of their perceived barriers and facilitators to health. Five primary domains emerged, including barriers (access, financial, personal, and neighborhood concerns), resources (personal and community), current behaviors (diet, physical activity, and program participation), definition of health (mental well-being, physical well-being, and health behaviors), and needs/interests in programming (health behavior-specific programs, non-health-related programs, child-focused programming, and qualities of programs and their leaders). Results demonstrate the complex interaction among social, environmental, and personal factors on health behaviors for this priority population, and highlight the need for community members' involvement in the development of community-based obesity prevention programming. © 2016 Society for Public Health Education.

The clustering of diet, physical activity and sedentary behavior in children and adolescents: a review.

PubMed

Leech, Rebecca M; McNaughton, Sarah A; Timperio, Anna

2014-01-22

Diet, physical activity (PA) and sedentary behavior are important, yet modifiable, determinants of obesity. Recent research into the clustering of these behaviors suggests that children and adolescents have multiple obesogenic risk factors. This paper reviews studies using empirical, data-driven methodologies, such as cluster analysis (CA) and latent class analysis (LCA), to identify clustering patterns of diet, PA and sedentary behavior among children or adolescents and their associations with socio-demographic indicators, and overweight and obesity. A literature search of electronic databases was undertaken to identify studies which have used data-driven methodologies to investigate the clustering of diet, PA and sedentary behavior among children and adolescents aged 5-18 years old. Eighteen studies (62% of potential studies) were identified that met the inclusion criteria, of which eight examined the clustering of PA and sedentary behavior and eight examined diet, PA and sedentary behavior. Studies were mostly cross-sectional and conducted in older children and adolescents (≥ 9 years). Findings from the review suggest that obesogenic cluster patterns are complex with a mixed PA/sedentary behavior cluster observed most frequently, but healthy and unhealthy patterning of all three behaviors was also reported. Cluster membership was found to differ according to age, gender and socio-economic status (SES). The tendency for older children/adolescents, particularly females, to comprise clusters defined by low PA was the most robust finding. Findings to support an association between obesogenic cluster patterns and overweight and obesity were inconclusive, with longitudinal research in this area limited. Diet, PA and sedentary behavior cluster together in complex ways that are not well understood. Further research, particularly in younger children, is needed to understand how cluster membership differs according to socio-demographic profile. Longitudinal research is also essential to establish how different cluster patterns track over time and their influence on the development of overweight and obesity.

The clustering of diet, physical activity and sedentary behavior in children and adolescents: a review

PubMed Central

2014-01-01

Diet, physical activity (PA) and sedentary behavior are important, yet modifiable, determinants of obesity. Recent research into the clustering of these behaviors suggests that children and adolescents have multiple obesogenic risk factors. This paper reviews studies using empirical, data-driven methodologies, such as cluster analysis (CA) and latent class analysis (LCA), to identify clustering patterns of diet, PA and sedentary behavior among children or adolescents and their associations with socio-demographic indicators, and overweight and obesity. A literature search of electronic databases was undertaken to identify studies which have used data-driven methodologies to investigate the clustering of diet, PA and sedentary behavior among children and adolescents aged 5–18 years old. Eighteen studies (62% of potential studies) were identified that met the inclusion criteria, of which eight examined the clustering of PA and sedentary behavior and eight examined diet, PA and sedentary behavior. Studies were mostly cross-sectional and conducted in older children and adolescents (≥9 years). Findings from the review suggest that obesogenic cluster patterns are complex with a mixed PA/sedentary behavior cluster observed most frequently, but healthy and unhealthy patterning of all three behaviors was also reported. Cluster membership was found to differ according to age, gender and socio-economic status (SES). The tendency for older children/adolescents, particularly females, to comprise clusters defined by low PA was the most robust finding. Findings to support an association between obesogenic cluster patterns and overweight and obesity were inconclusive, with longitudinal research in this area limited. Diet, PA and sedentary behavior cluster together in complex ways that are not well understood. Further research, particularly in younger children, is needed to understand how cluster membership differs according to socio-demographic profile. Longitudinal research is also essential to establish how different cluster patterns track over time and their influence on the development of overweight and obesity. PMID:24450617

Barcoding Human Physical Activity to Assess Chronic Pain Conditions

PubMed Central

Paraschiv-Ionescu, Anisoara; Perruchoud, Christophe; Buchser, Eric; Aminian, Kamiar

2012-01-01

Background Modern theories define chronic pain as a multidimensional experience – the result of complex interplay between physiological and psychological factors with significant impact on patients' physical, emotional and social functioning. The development of reliable assessment tools capable of capturing the multidimensional impact of chronic pain has challenged the medical community for decades. A number of validated tools are currently used in clinical practice however they all rely on self-reporting and are therefore inherently subjective. In this study we show that a comprehensive analysis of physical activity (PA) under real life conditions may capture behavioral aspects that may reflect physical and emotional functioning. Methodology PA was monitored during five consecutive days in 60 chronic pain patients and 15 pain-free healthy subjects. To analyze the various aspects of pain-related activity behaviors we defined the concept of PA ‘barcoding’. The main idea was to combine different features of PA (type, intensity, duration) to define various PA states. The temporal sequence of different states was visualized as a ‘barcode’ which indicated that significant information about daily activity can be contained in the amount and variety of PA states, and in the temporal structure of sequence. This information was quantified using complementary measures such as structural complexity metrics (information and sample entropy, Lempel-Ziv complexity), time spent in PA states, and two composite scores, which integrate all measures. The reliability of these measures to characterize chronic pain conditions was assessed by comparing groups of subjects with clinically different pain intensity. Conclusion The defined measures of PA showed good discriminative features. The results suggest that significant information about pain-related functional limitations is captured by the structural complexity of PA barcodes, which decreases when the intensity of pain increases. We conclude that a comprehensive analysis of daily-life PA can provide an objective appraisal of the intensity of pain. PMID:22384191

Breaking news dissemination in the media via propagation behavior based on complex network theory

NASA Astrophysics Data System (ADS)

Liu, Nairong; An, Haizhong; Gao, Xiangyun; Li, Huajiao; Hao, Xiaoqing

2016-07-01

The diffusion of breaking news largely relies on propagation behaviors in the media. The tremendous and intricate propagation relationships in the media form a complex network. An improved understanding of breaking news diffusion characteristics can be obtained through the complex network research. Drawing on the news data of Bohai Gulf oil spill event from June 2011 to May 2014, we constructed a weighted and directed complex network in which media are set as nodes, the propagation relationships as edges and the propagation times as the weight of the edges. The primary results show (1) the propagation network presents small world feature, which means relations among media are close and breaking news originating from any node can spread rapidly; (2) traditional media and official websites are the typical sources for news propagation, while business portals are news collectors and spreaders; (3) the propagation network is assortative and the group of core media facilities the spread of breaking news faster; (4) for online media, news originality factor become less important to propagation behaviors. This study offers a new insight to explore information dissemination from the perspective of statistical physics and is beneficial for utilizing the public opinion in a positive way.

The inhibitory spillover effect: Controlling the bladder makes better liars *

PubMed Central

Fenn, Elise; Blandón-Gitlin, Iris; Coons, Jennifer; Pineda, Catherine; Echon, Reinalyn

2015-01-01

The Inhibitory-Spillover-Effect (ISE) on a deception task was investigated. The ISE occurs when performance in one self-control task facilitates performance in another (simultaneously conducted) self-control task. Deceiving requires increased access to inhibitory control. We hypothesized that inducing liars to control urination urgency (physical inhibition) would facilitate control during deceptive interviews (cognitive inhibition). Participants drank small (low-control) or large (high-control) amounts of water. Next, they lied or told the truth to an interviewer. Third-party observers assessed the presence of behavioral cues and made true/lie judgments. In the high-control, but not the low-control condition, liars displayed significantly fewer behavioral cues to deception, more behavioral cues signaling truth, and provided longer and more complex accounts than truth-tellers. Accuracy detecting liars in the high-control condition was significantly impaired; observers revealed bias toward perceiving liars as truth-tellers. The ISE can operate in complex behaviors. Acts of deception can be facilitated by covert manipulations of self-control. PMID:26366466

On the usefulness of the concept of presence in virtual reality applications

NASA Astrophysics Data System (ADS)

Mestre, Daniel R.

2015-03-01

Virtual Reality (VR) leads to realistic experimental situations, while enabling researchers to have deterministic control on these situations, and to precisely measure participants' behavior. However, because more realistic and complex situations can be implemented, important questions arise, concerning the validity and representativeness of the observed behavior, with reference to a real situation. One example is the investigation of a critical (virtually dangerous) situation, in which the participant knows that no actual threat is present in the simulated situation, and might thus exhibit a behavioral response that is far from reality. This poses serious problems, for instance in training situations, in terms of transfer of learning to a real situation. Facing this difficult question, it seems necessary to study the relationships between three factors: immersion (physical realism), presence (psychological realism) and behavior. We propose a conceptual framework, in which presence is a necessary condition for the emergence of a behavior that is representative of what is observed in real conditions. Presence itself depends not only on physical immersive characteristics of the Virtual Reality setup, but also on contextual and psychological factors.

Cyberspatial mechanics.

PubMed

Bayne, Jay S

2008-06-01

In support of a generalization of systems theory, this paper introduces a new approach in modeling complex distributed systems. It offers an analytic framework for describing the behavior of interactive cyberphysical systems (CPSs), which are networked stationary or mobile information systems responsible for the real-time governance of physical processes whose behaviors unfold in cyberspace. The framework is predicated on a cyberspace-time reference model comprising three spatial dimensions plus time. The spatial domains include geospatial, infospatial, and sociospatial references, the latter describing relationships among sovereign enterprises (rational agents) that choose voluntarily to organize and interoperate for individual and mutual benefit through geospatial (physical) and infospatial (logical) transactions. Of particular relevance to CPSs are notions of timeliness and value, particularly as they relate to the real-time governance of physical processes and engagements with other cooperating CPS. Our overarching interest, as with celestial mechanics, is in the formation and evolution of clusters of cyberspatial objects and the federated systems they form.

Evolutionary fields can explain patterns of high-dimensional complexity in ecology

NASA Astrophysics Data System (ADS)

Wilsenach, James; Landi, Pietro; Hui, Cang

2017-04-01

One of the properties that make ecological systems so unique is the range of complex behavioral patterns that can be exhibited by even the simplest communities with only a few species. Much of this complexity is commonly attributed to stochastic factors that have very high-degrees of freedom. Orthodox study of the evolution of these simple networks has generally been limited in its ability to explain complexity, since it restricts evolutionary adaptation to an inertia-free process with few degrees of freedom in which only gradual, moderately complex behaviors are possible. We propose a model inspired by particle-mediated field phenomena in classical physics in combination with fundamental concepts in adaptation, which suggests that small but high-dimensional chaotic dynamics near to the adaptive trait optimum could help explain complex properties shared by most ecological datasets, such as aperiodicity and pink, fractal noise spectra. By examining a simple predator-prey model and appealing to real ecological data, we show that this type of complexity could be easily confused for or confounded by stochasticity, especially when spurred on or amplified by stochastic factors that share variational and spectral properties with the underlying dynamics.

Biology of Nanobots

NASA Astrophysics Data System (ADS)

Duan, Wentao; Pavlick, Ryan; Sen, Ayusman

2013-12-01

One of the more interesting recent discoveries has been the ability to design nano/microbots which catalytically harness the chemical energy in their environment to move autonomously. Their potential applications include delivery of materials, self-assembly of superstructures, and roving sensors. One emergent area of research is the study of their collective behavior and how they emulate living systems. The aim of this chapter is to describe the "biology" of nanobots, summarizing the fundamentals physics behind their motion and how the bots interact with each other to initiate complex emergent behavior.

Films, Needles, and Particles: A Comparative Study on the Ferroic Properties of Complex Oxides Nano-Structured in One, Two, and Three Dimensions

DTIC Science & Technology

2014-03-01

materials (2). .......................................................2 Figure 2. Theoretical SPE phase region in Temperature vs. Size for PbZr0.6Ti0.4O3...ferroelasticity, ferromagnetism , and ferrotoroidicity (whose existence has not yet been proven by physical observation). A multiferroic material exhibits more... materials all belong to the class of primary ferroics. As such, we can expect analogous behavior in certain physical properties across this class of

Logical Interactions in AN Expanded Space

NASA Astrophysics Data System (ADS)

Tadić, Bosiljka

Understanding the emergent behavior in many complex systems in the physical world and society requires a detailed study of dynamical phenomena occurring and mutually coupled at different scales. The brain processes underlying the social conduct of each, and the emergent social behavior of interacting individuals on a larger scale, represent striking examples of the multiscale complexity. Studies of the human brain, a paradigm of a complex functional system, are enabled by a wealth of brain imaging data that provide clues of how we comprehend space, time, languages, numbers, and differentiate normal from diseased individuals, for example. The social brain, a neural basis for social cognition, represents a dynamically organized part of the brain which is involved in the inference of thoughts, feelings, and intentions going on in the brains of others. Research in this currently unexplored area opens a new perspective on the genesis of the societal organization at different levels and the associated social values...

Transforming Better Babies into Fitter Families: archival resources and the history of American eugenics movement, 1908-1930.

PubMed

Selden, Steven

2005-06-01

In the early 1920s, determinist conceptions of biology helped to transform Better Babies contest into Fitter Families competitions with a strong commitment to controlled human breeding. While the earlier competitions were concerned for physical and mental standards, the latter contests collected data on a broad range of presumed hereditary characters. The complex behaviors thought to be determined by one's heredity included being generous, jealous, and cruel. In today's context, the popular media often interpret advances in molecular genetics in a similarly reductive and determinist fashion. This paper argues that such a narrow interpretation of contemporary biology unnecessarily constrains the public in developing social policies concerning complex social behavior ranging from crime to intelligence.

Automatically Characterizing Sensory-Motor Patterns Underlying Reach-to-Grasp Movements on a Physical Depth Inversion Illusion.

PubMed

Nguyen, Jillian; Majmudar, Ushma V; Ravaliya, Jay H; Papathomas, Thomas V; Torres, Elizabeth B

2015-01-01

Recently, movement variability has been of great interest to motor control physiologists as it constitutes a physical, quantifiable form of sensory feedback to aid in planning, updating, and executing complex actions. In marked contrast, the psychological and psychiatric arenas mainly rely on verbal descriptions and interpretations of behavior via observation. Consequently, a large gap exists between the body's manifestations of mental states and their descriptions, creating a disembodied approach in the psychological and neural sciences: contributions of the peripheral nervous system to central control, executive functions, and decision-making processes are poorly understood. How do we shift from a psychological, theorizing approach to characterize complex behaviors more objectively? We introduce a novel, objective, statistical framework, and visuomotor control paradigm to help characterize the stochastic signatures of minute fluctuations in overt movements during a visuomotor task. We also quantify a new class of covert movements that spontaneously occur without instruction. These are largely beneath awareness, but inevitably present in all behaviors. The inclusion of these motions in our analyses introduces a new paradigm in sensory-motor integration. As it turns out, these movements, often overlooked as motor noise, contain valuable information that contributes to the emergence of different kinesthetic percepts. We apply these new methods to help better understand perception-action loops. To investigate how perceptual inputs affect reach behavior, we use a depth inversion illusion (DII): the same physical stimulus produces two distinct depth percepts that are nearly orthogonal, enabling a robust comparison of competing percepts. We find that the moment-by-moment empirically estimated motor output variability can inform us of the participants' perceptual states, detecting physiologically relevant signals from the peripheral nervous system that reveal internal mental states evoked by the bi-stable illusion. Our work proposes a new statistical platform to objectively separate changes in visual perception by quantifying the unfolding of movement, emphasizing the importance of including in the motion analyses all overt and covert aspects of motor behavior.

Fast parametric relationships for the large-scale reservoir simulation of mixed CH 4-CO 2 gas hydrate systems

DOE PAGES

Reagan, Matthew T.; Moridis, George J.; Seim, Katie S.

2017-03-27

A recent Department of Energy field test on the Alaska North Slope has increased interest in the ability to simulate systems of mixed CO 2-CH 4 hydrates. However, the physically realistic simulation of mixed-hydrate simulation is not yet a fully solved problem. Limited quantitative laboratory data leads to the use of various ab initio, statistical mechanical, or other mathematic representations of mixed-hydrate phase behavior. Few of these methods are suitable for inclusion in reservoir simulations, particularly for systems with large number of grid elements, 3D systems, or systems with complex geometric configurations. In this paper, we present a set ofmore » fast parametric relationships describing the thermodynamic properties and phase behavior of a mixed methane-carbon dioxide hydrate system. We use well-known, off-the-shelf hydrate physical properties packages to generate a sufficiently large dataset, select the most convenient and efficient mathematical forms, and fit the data to those forms to create a physical properties package suitable for inclusion in the TOUGH+ family of codes. Finally, the mapping of the phase and thermodynamic space reveals the complexity of the mixed-hydrate system and allows understanding of the thermodynamics at a level beyond what much of the existing laboratory data and literature currently offer.« less

Fast parametric relationships for the large-scale reservoir simulation of mixed CH4-CO2 gas hydrate systems

NASA Astrophysics Data System (ADS)

Reagan, Matthew T.; Moridis, George J.; Seim, Katie S.

2017-06-01

A recent Department of Energy field test on the Alaska North Slope has increased interest in the ability to simulate systems of mixed CO2-CH4 hydrates. However, the physically realistic simulation of mixed-hydrate simulation is not yet a fully solved problem. Limited quantitative laboratory data leads to the use of various ab initio, statistical mechanical, or other mathematic representations of mixed-hydrate phase behavior. Few of these methods are suitable for inclusion in reservoir simulations, particularly for systems with large number of grid elements, 3D systems, or systems with complex geometric configurations. In this work, we present a set of fast parametric relationships describing the thermodynamic properties and phase behavior of a mixed methane-carbon dioxide hydrate system. We use well-known, off-the-shelf hydrate physical properties packages to generate a sufficiently large dataset, select the most convenient and efficient mathematical forms, and fit the data to those forms to create a physical properties package suitable for inclusion in the TOUGH+ family of codes. The mapping of the phase and thermodynamic space reveals the complexity of the mixed-hydrate system and allows understanding of the thermodynamics at a level beyond what much of the existing laboratory data and literature currently offer.

Fast parametric relationships for the large-scale reservoir simulation of mixed CH 4-CO 2 gas hydrate systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reagan, Matthew T.; Moridis, George J.; Seim, Katie S.

A recent Department of Energy field test on the Alaska North Slope has increased interest in the ability to simulate systems of mixed CO 2-CH 4 hydrates. However, the physically realistic simulation of mixed-hydrate simulation is not yet a fully solved problem. Limited quantitative laboratory data leads to the use of various ab initio, statistical mechanical, or other mathematic representations of mixed-hydrate phase behavior. Few of these methods are suitable for inclusion in reservoir simulations, particularly for systems with large number of grid elements, 3D systems, or systems with complex geometric configurations. In this paper, we present a set ofmore » fast parametric relationships describing the thermodynamic properties and phase behavior of a mixed methane-carbon dioxide hydrate system. We use well-known, off-the-shelf hydrate physical properties packages to generate a sufficiently large dataset, select the most convenient and efficient mathematical forms, and fit the data to those forms to create a physical properties package suitable for inclusion in the TOUGH+ family of codes. Finally, the mapping of the phase and thermodynamic space reveals the complexity of the mixed-hydrate system and allows understanding of the thermodynamics at a level beyond what much of the existing laboratory data and literature currently offer.« less

Crossover from antipersistent to persistent behavior in time series possessing the generalyzed dynamic scaling law

NASA Astrophysics Data System (ADS)

Balankin, Alexander S.; Morales Matamoros, Oswaldo; Gálvez M., Ernesto; Pérez A., Alfonso

2004-03-01

The behavior of crude oil price volatility is analyzed within a conceptual framework of kinetic roughening of growing interfaces. We find that the persistent long-horizon volatilities satisfy the Family-Viscek dynamic scaling ansatz, whereas the mean-reverting in time short horizon volatilities obey the generalized scaling law with continuously varying scaling exponents. Furthermore we find that the crossover from antipersistent to persistent behavior is accompanied by a change in the type of volatility distribution. These phenomena are attributed to the complex avalanche dynamics of crude oil markets and so a similar behavior may be observed in a wide variety of physical systems governed by avalanche dynamics.

Dynamical complexity detection in geomagnetic activity indices using wavelet transforms and Tsallis entropy

NASA Astrophysics Data System (ADS)

Balasis, G.; Daglis, I. A.; Papadimitriou, C.; Kalimeri, M.; Anastasiadis, A.; Eftaxias, K.

2008-12-01

Dynamical complexity detection for output time series of complex systems is one of the foremost problems in physics, biology, engineering, and economic sciences. Especially in magnetospheric physics, accurate detection of the dissimilarity between normal and abnormal states (e.g. pre-storm activity and magnetic storms) can vastly improve space weather diagnosis and, consequently, the mitigation of space weather hazards. Herein, we examine the fractal spectral properties of the Dst data using a wavelet analysis technique. We show that distinct changes in associated scaling parameters occur (i.e., transition from anti- persistent to persistent behavior) as an intense magnetic storm approaches. We then analyze Dst time series by introducing the non-extensive Tsallis entropy, Sq, as an appropriate complexity measure. The Tsallis entropy sensitively shows the complexity dissimilarity among different "physiological" (normal) and "pathological" states (intense magnetic storms). The Tsallis entropy implies the emergence of two distinct patterns: (i) a pattern associated with the intense magnetic storms, which is characterized by a higher degree of organization, and (ii) a pattern associated with normal periods, which is characterized by a lower degree of organization.

A "Bit" of Quantum Mechanics

ERIC Educational Resources Information Center

Oss, Stefano; Rosi, Tommaso

2015-01-01

We have developed an app for iOS-based smart-phones/tablets that allows a 3-D, complex phase-based colorful visualization of hydrogen atom wave functions. Several important features of the quantum behavior of atomic orbitals can easily be made evident, thus making this app a useful companion in introductory modern physics classes. There are many…

Evolution of Brain and Language

ERIC Educational Resources Information Center

Schoenemann, P. Thomas

2009-01-01

The evolution of language and the evolution of the brain are tightly interlinked. Language evolution represents a special kind of adaptation, in part because language is a complex behavior (as opposed to a physical feature) but also because changes are adaptive only to the extent that they increase either one's understanding of others, or one's…

Active particles in complex and crowded environments

DOE PAGES

Bechinger, Clemens; Di Leonardo, Roberto; Löwen, Hartmut; ...

2016-11-23

Differently from passive Brownian particles, active particles, also known as self-propelled Brownian particles or microswimmers and nanoswimmers, are capable of taking up energy from their environment and converting it into directed motion. Because of this constant flow of energy, their behavior can be explained and understood only within the framework of nonequilibrium physics. In the biological realm, many cells perform directed motion, for example, as a way to browse for nutrients or to avoid toxins. Inspired by these motile microorganisms, researchers have been developing artificial particles that feature similar swimming behaviors based on different mechanisms. These man-made micromachines and nanomachinesmore » hold a great potential as autonomous agents for health care, sustainability, and security applications. Finally, with a focus on the basic physical features of the interactions of self-propelled Brownian particles with a crowded and complex environment, this comprehensive review will provide a guided tour through its basic principles, the development of artificial self-propelling microparticles and nanoparticles, and their application to the study of nonequilibrium phenomena, as well as the open challenges that the field is currently facing.« less

Probing AGN Accretion Physics through AGN Variability: Insights from Kepler

NASA Astrophysics Data System (ADS)

Kasliwal, Vishal Pramod

Active Galactic Nuclei (AGN) exhibit large luminosity variations over the entire electromagnetic spectrum on timescales ranging from hours to years. The variations in luminosity are devoid of any periodic character and appear stochastic. While complex correlations exist between the variability observed in different parts of the electromagnetic spectrum, no frequency band appears to be completely dominant, suggesting that the physical processes producing the variability are exceedingly rich and complex. In the absence of a clear theoretical explanation of the variability, phenomenological models are used to study AGN variability. The stochastic behavior of AGN variability makes formulating such models difficult and connecting them to the underlying physics exceedingly hard. We study AGN light curves serendipitously observed by the NASA Kepler planet-finding mission. Compared to previous ground-based observations, Kepler offers higher precision and a smaller sampling interval resulting in potentially higher quality light curves. Using structure functions, we demonstrate that (1) the simplest statistical model of AGN variability, the damped random walk (DRW), is insufficient to characterize the observed behavior of AGN light curves; and (2) variability begins to occur in AGN on time-scales as short as hours. Of the 20 light curves studied by us, only 3-8 may be consistent with the DRW. The structure functions of the AGN in our sample exhibit complex behavior with pronounced dips on time-scales of 10-100 d suggesting that AGN variability can be very complex and merits further analysis. We examine the accuracy of the Kepler pipeline-generated light curves and find that the publicly available light curves may require re-processing to reduce contamination from field sources. We show that while the re-processing changes the exact PSD power law slopes inferred by us, it is unlikely to change the conclusion of our structure function study-Kepler AGN light curves indicate that the DRW is insufficient to characterize AGN variability. We provide a new approach to probing accretion physics with variability by decomposing observed light curves into a set of impulses that drive diffusive processes using C-ARMA models. Applying our approach to Kepler data, we demonstrate how the time-scales reported in the literature can be interpreted in the context of the growth and decay time-scales for flux perturbations and tentatively identify the flux perturbation driving process with accretion disk turbulence on length-scales much longer than the characteristic eddy size. Our analysis technique is applicable to (1) studying the connection between AGN sub-type and variability properties; (2) probing the origins of variability by studying the multi-wavelength behavior of AGN; (3) testing numerical simulations of accretion flows with the goal of creating a library of the variability properties of different accretion mechanisms; (4) hunting for changes in the behavior of the accretion flow by block-analyzing observed light curves; and (5) constraining the sampling requirements of future surveys of AGN variability.

Neuroengineering control and regulation of behavior

NASA Astrophysics Data System (ADS)

Wróbel, A.; Radzewicz, C.; Mankiewicz, L.; Hottowy, P.; Knapska, E.; Konopka, W.; Kublik, E.; Radwańska, K.; Waleszczyk, W. J.; Wójcik, D. K.

2014-11-01

To monitor neuronal circuits involved in emotional modulation of sensory processing we proposed a plan to establish novel research techniques combining recent biological, technical and analytical discoveries. The project was granted by National Science Center and we started to build a new experimental model for studying the selected circuits of genetically marked and behaviorally activated neurons. To achieve this goal we will combine the pioneering, interdisciplinary expertise of four Polish institutions: (i) the Nencki Institute of Experimental Biology (Polish Academy of Sciences) will deliver the expertise on genetically modified mice and rats, mapping of the neuronal circuits activated by behavior, monitoring complex behaviors measured in the IntelliCage system, electrophysiological brain activity recordings by multielectrodes in behaving animals, analysis and modeling of behavioral and electrophysiological data; (ii) the AGH University of Science and Technology (Faculty of Physics and Applied Computer Sciences) will use its experience in high-throughput electronics to build multichannel systems for recording the brain activity of behaving animals; (iii) the University of Warsaw (Faculty of Physics) and (iv) the Center for Theoretical Physics (Polish Academy of Sciences) will construct optoelectronic device for remote control of opto-animals produced in the Nencki Institute based on the unique experience in laser sources, studies of light propagation and its interaction with condensed media, wireless medical robotic systems, fast readout opto-electronics with control software and micromechanics.

Learning from physics text: A synthesis of recent research

NASA Astrophysics Data System (ADS)

Alexander, Patricia A.; Kulikowich, Jonna M.

Learning from physics text is described as a complex interaction of learner, text, and context variables. As a multidimensional procedure, text processing in the domain of physics relies on readers' knowledge and interest, and on readers' ability to monitor or regulate their processing. Certain textual features intended to assist readers in understanding and remembering physics content may actually work to the detriment of those very processes. Inclusion of seductive details and the incorporation of analogies may misdirect readers' attention or may increase processing demands, particularly in those cases when readers' physics knowledge is low. The questioning behaviors of teachers also impact on the task of comprehending physics texts. Finally, within the context of the classroom, the information that teachers dispense or the materials they employ can significantly influence the process of learning from physics text.

An integrated brain-behavior model for working memory.

PubMed

Moser, D A; Doucet, G E; Ing, A; Dima, D; Schumann, G; Bilder, R M; Frangou, S

2017-12-05

Working memory (WM) is a central construct in cognitive neuroscience because it comprises mechanisms of active information maintenance and cognitive control that underpin most complex cognitive behavior. Individual variation in WM has been associated with multiple behavioral and health features including demographic characteristics, cognitive and physical traits and lifestyle choices. In this context, we used sparse canonical correlation analyses (sCCAs) to determine the covariation between brain imaging metrics of WM-network activation and connectivity and nonimaging measures relating to sensorimotor processing, affective and nonaffective cognition, mental health and personality, physical health and lifestyle choices derived from 823 healthy participants derived from the Human Connectome Project. We conducted sCCAs at two levels: a global level, testing the overall association between the entire imaging and behavioral-health data sets; and a modular level, testing associations between subsets of the two data sets. The behavioral-health and neuroimaging data sets showed significant interdependency. Variables with positive correlation to the neuroimaging variate represented higher physical endurance and fluid intelligence as well as better function in multiple higher-order cognitive domains. Negatively correlated variables represented indicators of suboptimal cardiovascular and metabolic control and lifestyle choices such as alcohol and nicotine use. These results underscore the importance of accounting for behavioral-health factors in neuroimaging studies of WM and provide a neuroscience-informed framework for personalized and public health interventions to promote and maintain the integrity of the WM network.Molecular Psychiatry advance online publication, 5 December 2017; doi:10.1038/mp.2017.247.

Optothermal transport behavior in whispering gallery mode optical cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soltani, Soheil; Armani, Andrea M., E-mail: armani@usc.edu; Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089

Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longermore » solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.« less

On the polymer physics origins of protein folding thermodynamics.

PubMed

Taylor, Mark P; Paul, Wolfgang; Binder, Kurt

2016-11-07

A remarkable feature of the spontaneous folding of many small proteins is the striking similarity in the thermodynamics of the folding process. This process is characterized by simple two-state thermodynamics with large and compensating changes in entropy and enthalpy and a funnel-like free energy landscape with a free-energy barrier that varies linearly with temperature. One might attribute the commonality of this two-state folding behavior to features particular to these proteins (e.g., chain length, hydrophobic/hydrophilic balance, attributes of the native state) or one might suspect that this similarity in behavior has a more general polymer-physics origin. Here we show that this behavior is also typical for flexible homopolymer chains with sufficiently short range interactions. Two-state behavior arises from the presence of a low entropy ground (folded) state separated from a set of high entropy disordered (unfolded) states by a free energy barrier. This homopolymer model exhibits a funneled free energy landscape that reveals a complex underlying dynamics involving competition between folding and non-folding pathways. Despite the presence of multiple pathways, this simple physics model gives the robust result of two-state thermodynamics for both the cases of folding from a basin of expanded coil states and from a basin of compact globule states.

On the polymer physics origins of protein folding thermodynamics

NASA Astrophysics Data System (ADS)

Taylor, Mark P.; Paul, Wolfgang; Binder, Kurt

2016-11-01

A remarkable feature of the spontaneous folding of many small proteins is the striking similarity in the thermodynamics of the folding process. This process is characterized by simple two-state thermodynamics with large and compensating changes in entropy and enthalpy and a funnel-like free energy landscape with a free-energy barrier that varies linearly with temperature. One might attribute the commonality of this two-state folding behavior to features particular to these proteins (e.g., chain length, hydrophobic/hydrophilic balance, attributes of the native state) or one might suspect that this similarity in behavior has a more general polymer-physics origin. Here we show that this behavior is also typical for flexible homopolymer chains with sufficiently short range interactions. Two-state behavior arises from the presence of a low entropy ground (folded) state separated from a set of high entropy disordered (unfolded) states by a free energy barrier. This homopolymer model exhibits a funneled free energy landscape that reveals a complex underlying dynamics involving competition between folding and non-folding pathways. Despite the presence of multiple pathways, this simple physics model gives the robust result of two-state thermodynamics for both the cases of folding from a basin of expanded coil states and from a basin of compact globule states.

Empathy and moral emotions in post-apartheid South Africa: an fMRI investigation.

PubMed

Fourie, Melike M; Stein, Dan J; Solms, Mark; Gobodo-Madikizela, Pumla; Decety, Jean

2017-06-01

Moral emotions elicited in response to others' suffering are mediated by empathy and affect how we respond to their pain. South Africa provides a unique opportunity to study group processes given its racially divided past. The present study seeks insights into aspects of the moral brain by investigating behavioral and functional MRI responses of White and Black South Africans who lived through apartheid to in- and out-group physical and social pain. Whereas the physical pain task featured faces expressing dynamic suffering, the social pain task featured victims of apartheid violence from the South African Truth and Reconciliation Commission to elicit heartfelt emotion. Black participants' behavioral responses were suggestive of in-group favoritism, whereas White participants' responses were apparently egalitarian. However, all participants showed significant in-group biases in activation in the amygdala (physical pain), as well as areas involved in mental state representation, including the precuneus, temporoparietal junction (TPJ) and frontal pole (physical and social pain). Additionally, Black participants reacted with heightened moral indignation to own-race suffering, whereas White participants reacted with heightened shame to Black suffering, which was associated with blunted neural empathic responding. These findings provide ecologically valid insights into some behavioral and brain processes involved in complex moral situations. © The Author (2017). Published by Oxford University Press.

Empathy and moral emotions in post-apartheid South Africa: an fMRI investigation

PubMed Central

Stein, Dan J.; Solms, Mark; Gobodo-Madikizela, Pumla; Decety, Jean

2017-01-01

Abstract Moral emotions elicited in response to others’ suffering are mediated by empathy and affect how we respond to their pain. South Africa provides a unique opportunity to study group processes given its racially divided past. The present study seeks insights into aspects of the moral brain by investigating behavioral and functional MRI responses of White and Black South Africans who lived through apartheid to in- and out-group physical and social pain. Whereas the physical pain task featured faces expressing dynamic suffering, the social pain task featured victims of apartheid violence from the South African Truth and Reconciliation Commission to elicit heartfelt emotion. Black participants’ behavioral responses were suggestive of in-group favoritism, whereas White participants’ responses were apparently egalitarian. However, all participants showed significant in-group biases in activation in the amygdala (physical pain), as well as areas involved in mental state representation, including the precuneus, temporoparietal junction (TPJ) and frontal pole (physical and social pain). Additionally, Black participants reacted with heightened moral indignation to own-race suffering, whereas White participants reacted with heightened shame to Black suffering, which was associated with blunted neural empathic responding. These findings provide ecologically valid insights into some behavioral and brain processes involved in complex moral situations. PMID:28338783

The physics of flocking: Correlation as a compass from experiments to theory

NASA Astrophysics Data System (ADS)

Cavagna, Andrea; Giardina, Irene; Grigera, Tomás S.

2018-01-01

Collective behavior in biological systems is a complex topic, to say the least. It runs wildly across scales in both space and time, involving taxonomically vastly different organisms, from bacteria and cell clusters, to insect swarms and up to vertebrate groups. It entails concepts as diverse as coordination, emergence, interaction, information, cooperation, decision-making, and synchronization. Amid this jumble, however, we cannot help noting many similarities between collective behavior in biological systems and collective behavior in statistical physics, even though none of these organisms remotely looks like an Ising spin. Such similarities, though somewhat qualitative, are startling, and regard mostly the emergence of global dynamical patterns qualitatively different from individual behavior, and the development of system-level order from local interactions. It is therefore tempting to describe collective behavior in biology within the conceptual framework of statistical physics, in the hope to extend to this new fascinating field at least part of the great predictive power of theoretical physics. In this review we propose that the conceptual cornerstone of this ambitious program be that of correlation. To illustrate this idea we address the case of collective behavior in bird flocks. Two key threads emerge, as two sides of one single story: the presence of scale-free correlations and the dynamical mechanism of information transfer. We discuss first static correlations in starling flocks, in particular the experimental finding of their scale-free nature, the formulation of models that account for this fact using maximum entropy, and the relation of scale-free correlations to information transfer. This is followed by a dynamic treatment of information propagation (propagation of turns across a flock), starting with a discussion of experimental results and following with possible theoretical explanations of those, which require the addition of behavioral inertia to existing theories of flocking. We finish with the definition and analysis of space-time correlations and their relevance to the detection of inertial behavior in the absence of external perturbations.

Living matter—nexus of physics and biology in the 21st century

PubMed Central

Gardel, Margaret L.

2012-01-01

Cells are made up of complex assemblies of cytoskeletal proteins that facilitate force transmission from the molecular to cellular scale to regulate cell shape and force generation. The “living matter” formed by the cytoskeleton facilitates versatile and robust behaviors of cells, including their migration, adhesion, division, and morphology, that ultimately determine tissue architecture and mechanics. Elucidating the underlying physical principles of such living matter provides great opportunities in both biology and physics. For physicists, the cytoskeleton provides an exceptional toolbox to study materials far from equilibrium. For biologists, these studies will provide new understanding of how molecular-scale processes determine cell morphological changes. PMID:23112229

MAP-IT: A Practical Tool for Planning Complex Behavior Modification Interventions.

PubMed

Hansen, Sylvia; Kanning, Martina; Lauer, Romy; Steinacker, Jürgen M; Schlicht, Wolfgang

2017-09-01

Health research often aims to prevent noncommunicable diseases and to improve individual and public health by discovering intervention strategies that are effective in changing behavior and/or environments that are detrimental to one's health. Ideally, findings from original research support practitioners in planning and implementing effective interventions. Unfortunately, interventions often fail to overcome the translational block between science and practice. They often ignore theoretical knowledge, overlook empirical evidence, and underrate the impact of the environment. Accordingly, sustainable changes in individual behavior and/or the environment are difficult to achieve. Developing theory-driven and evidence-based interventions in the real world is a complex task. Existing implementation frameworks and theories often do not meet the needs of health practitioners. The purpose of this article is to synthesize existing frameworks and to provide a tool, the Matrix Assisting Practitioner's Intervention Planning Tool (MAP-IT), that links research to practice and helps practitioners to design multicomponent interventions. In this article, we use physical activity of older adults as an example to explain the rationale of MAP-IT. In MAP-IT, individual as well as environmental mechanisms are listed and behavior change techniques are linked to these mechanisms and to intervention components. MAP-IT is theory-driven and evidence-based. It is time-saving and helpful for practitioners when planning complex interventions.

DNA surface hybridization regimes

PubMed Central

Gong, Ping; Levicky, Rastislav

2008-01-01

Surface hybridization reactions, in which sequence-specific recognition occurs between immobilized and solution nucleic acids, are routinely carried out to quantify and interpret genomic information. Although hybridization is fairly well understood in bulk solution, the greater complexity of an interfacial environment presents new challenges to a fundamental understanding, and hence application, of these assays. At a surface, molecular interactions are amplified by the two-dimensional nature of the immobilized layer, which focuses the nucleic acid charge and concentration to levels not encountered in solution, and which impacts the hybridization behavior in unique ways. This study finds that, at low ionic strengths, an electrostatic balance between the concentration of immobilized oligonucleotide charge and solution ionic strength governs the onset of hybridization. As ionic strength increases, the importance of electrostatics diminishes and the hybridization behavior becomes more complex. Suppression of hybridization affinity constants relative to solution values, and their weakened dependence on the concentration of DNA counterions, indicate that the immobilized strands form complexes that compete with hybridization to analyte strands. Moreover, an unusual regime is observed in which the surface coverage of immobilized oligonucleotides does not significantly influence the hybridization behavior, despite physical closeness and hence compulsory interactions between sites. These results are interpreted and summarized in a diagram of hybridization regimes that maps specific behaviors to experimental ranges of ionic strength and probe coverage. PMID:18381819

Unrewarded Object Combinations in Captive Parrots

PubMed Central

Auersperg, Alice Marie Isabel; Oswald, Natalie; Domanegg, Markus; Gajdon, Gyula Koppany; Bugnyar, Thomas

2015-01-01

In primates, complex object combinations during play are often regarded as precursors of functional behavior. Here we investigate combinatory behaviors during unrewarded object manipulation in seven parrot species, including kea, African grey parrots and Goffin cockatoos, three species previously used as model species for technical problem solving. We further examine a habitually tool using species, the black palm cockatoo. Moreover, we incorporate three neotropical species, the yellow- and the black-billed Amazon and the burrowing parakeet. Paralleling previous studies on primates and corvids, free object-object combinations and complex object-substrate combinations such as inserting objects into tubes/holes or stacking rings onto poles prevailed in the species previously linked to advanced physical cognition and tool use. In addition, free object-object combinations were intrinsically structured in Goffin cockatoos and in kea. PMID:25984564

Does mothers' employment affect adolescents' weight and activity levels? Improving our empirical estimates.

PubMed

Martin, Molly A; Lippert, Adam M; Chandler, Kelly D; Lemmon, Megan

2018-04-01

Women's lives are marked by complex work and family routines - routines that have implications for their children's health. Prior research suggests a link between mothers' work hours and their children's weight, but few studies investigate the child health implications of increasingly common work arrangements, such as telecommuting and flexible work schedules. We examine whether changes in mothers' work arrangements are associated with changes in adolescents' weight, physical activity, and sedentary behavior using longitudinal data and fixed effects models to better account for mothers' social selection in to different work arrangements and children's underlying preferences. With data from the National Longitudinal Study of Adolescent to Adult Health ( N = 10,518), we find that changes in mothers' work arrangements are not significantly associated with adolescents' weight gain or physical activity but are significantly associated with adolescents' sedentary behavior. Adolescents' sedentary behavior declines when mothers become more available after school and increases when mothers work more hours or become unemployed. In sum, after accounting for unobserved, stable traits, including mothers' selection into jobs with more or less flexibility, mothers' work arrangements are most strongly associated with adolescents' sedentary behavior.

Pubertal timing and adolescent sexual behavior in girls.

PubMed

Moore, Sarah R; Harden, K Paige; Mendle, Jane

2014-06-01

Girls who experience earlier pubertal timing relative to peers also exhibit earlier timing of sexual intercourse and more unstable sexual relationships. Although pubertal development initiates feelings of physical desire, the transition into romantic and sexual relationships involves complex biological and social processes contributing both to physical maturation and to individual interpretations of pubertal experiences. Using a sample of female sibling pairs (n = 923 pairs) from the National Longitudinal Study of Adolescent Health, the present study investigated associations among menarche and perceived pubertal timing, age of first sexual intercourse (AFI), and adolescent dating and sexual behavior using a behavioral genetic approach. Genetic factors influencing age at menarche and perceived pubertal timing predicted AFI through shared genetic pathways, whereas genetic factors related only to perceived pubertal timing predicted engagement in dating, romantic sex, and nonromantic sex in the previous 18 months. These results suggest that a girl's interpretation of her pubertal timing beyond objective timing is important to consider for the timing and the contexts of romantic and reproductive behavior. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Morphology and proteome characterization of the salivary glands of the western chinch bug, Blissus occiduus (Hemiptera: Blissidae)

USDA-ARS?s Scientific Manuscript database

The western chinch bug, Blissus occiduus Barber, is a serious pest of buffalograss due to physical and chemical damage caused during the feeding process. Although previous work has investigated the feeding behaviors of chinch bugs in the Blissus complex, no study to date has explored salivary gland ...

Ecosystem services and preventive medicine a natural connection

Treesearch

Viniece L. Jennings; Claire K. Larson; Lincoln R. Larson

2016-01-01

Modern public health challenges require inter- disciplinary solutions that integrate knowl- edge of  human behavior and its complex relationship with the physical environment. Historically, this discourse was dominated by studies  of hazards and other negative health consequences associated with human–environment interactions.  However, growing evidence1 suggests that...

Modeling Goal Setting within a Multimedia Environment on Complex Physics Content

ERIC Educational Resources Information Center

Twyford, Jessica; Craig, Scotty D.

2017-01-01

Observational tutoring has been found to be an effective method for teaching a variety of subjects by reusing dialogue from previous successful tutoring sessions. While it has been shown content can be learned through observational tutoring, it has yet to been examined if a secondary behavior such as goal setting can be influenced. The present…

Evolution of speech and evolution of language.

PubMed

de Boer, Bart

2017-02-01

Speech is the physical signal used to convey spoken language. Because of its physical nature, speech is both easier to compare with other species' behaviors and easier to study in the fossil record than other aspects of language. Here I argue that convergent fossil evidence indicates adaptations for complex vocalizations at least as early as the common ancestor of Neanderthals and modern humans. Furthermore, I argue that it is unlikely that language evolved separately from speech, but rather that gesture, speech, and song coevolved to provide both a multimodal communication system and a musical system. Moreover, coevolution must also have played a role by allowing both cognitive and anatomical adaptations to language and speech to evolve in parallel. Although such a coevolutionary scenario is complex, it is entirely plausible from a biological point of view.

Transfer entropy in physical systems and the arrow of time

NASA Astrophysics Data System (ADS)

Spinney, Richard E.; Lizier, Joseph T.; Prokopenko, Mikhail

2016-08-01

Recent developments have cemented the realization that many concepts and quantities in thermodynamics and information theory are shared. In this paper, we consider a highly relevant quantity in information theory and complex systems, the transfer entropy, and explore its thermodynamic role by considering the implications of time reversal upon it. By doing so we highlight the role of information dynamics on the nuanced question of observer perspective within thermodynamics by relating the temporal irreversibility in the information dynamics to the configurational (or spatial) resolution of the thermodynamics. We then highlight its role in perhaps the most enduring paradox in modern physics, the manifestation of a (thermodynamic) arrow of time. We find that for systems that process information such as those undergoing feedback, a robust arrow of time can be formulated by considering both the apparent physical behavior which leads to conventional entropy production and the information dynamics which leads to a quantity we call the information theoretic arrow of time. We also offer an interpretation in terms of optimal encoding of observed physical behavior.

Auditing the socio-environmental determinants of motivation towards physical activity or sedentariness in work-aged adults: a qualitative study.

PubMed

Keegan, Richard; Middleton, Geoff; Henderson, Hannah; Girling, Mica

2016-05-26

There is a lack of understanding of work aged adults' (30-60 years old) perspectives on the motivation of physical activity versus sedentariness. This study aims to: (1) identify which socio-environmental factors motivate physical activity and/or sedentary behavior, in adults aged 30-60 years; and (2) explore how these motivators interact and combine. Fifteen work-aged adults who, were able to engage in physical activity (Mean age = 43.9 years; SD 9.6, range 31-59), participated in semi-structured interviews. Inductive content analysis was used to generate an inventory of socio-environmental factors and their specific influences on motivation towards physical activity or sedentariness. Key socio-environmental agents found to influence motivation included: Spouse/partner, parents, children, siblings, whole family, grandchildren, friends, work-mates, neighbors, strangers, team-mates and class-mates, instructors, health care professionals, employers, gyms and health companies, governments, media and social media, cultural norms, and the physical environment. Mechanisms fell into five broad themes of socio-environmental motivation for both physical activity and sedentariness: (1) competence and progress; (2) informational influences, (3) emotional influences, (4) pragmatics and logistics, and (5) relationships. Similar socio-environmental factors were frequently reported as able to motivate both activity and sedentariness. Likewise, individual categories of influence could also motivate both behaviors, depending on context. The findings of this paper 'unpack' theoretical concepts into specific and targeted behavioral recommendations. The data suggested no simple solutions for promoting physical activity or reducing sedentariness, but rather complex and interacting systems surrounding work-aged adults. Findings also suggest that health professionals should be encouraged to support adults' health by examining the socio-environmental motivational influences, or 'motivational atmosphere'.

A general computation model based on inverse analysis principle used for rheological analysis of W/O rapeseed and soybean oil emulsions

NASA Astrophysics Data System (ADS)

Vintila, Iuliana; Gavrus, Adinel

2017-10-01

The present research paper proposes the validation of a rigorous computation model used as a numerical tool to identify rheological behavior of complex emulsions W/O. Considering a three-dimensional description of a general viscoplastic flow it is detailed the thermo-mechanical equations used to identify fluid or soft material's rheological laws starting from global experimental measurements. Analyses are conducted for complex emulsions W/O having generally a Bingham behavior using the shear stress - strain rate dependency based on a power law and using an improved analytical model. Experimental results are investigated in case of rheological behavior for crude and refined rapeseed/soybean oils and four types of corresponding W/O emulsions using different physical-chemical composition. The rheological behavior model was correlated with the thermo-mechanical analysis of a plane-plane rheometer, oil content, chemical composition, particle size and emulsifier's concentration. The parameters of rheological laws describing the industrial oils and the W/O concentrated emulsions behavior were computed from estimated shear stresses using a non-linear regression technique and from experimental torques using the inverse analysis tool designed by A. Gavrus (1992-2000).

What every conservation biologist should know about economic theory.

PubMed

Gowdy, John; Hall, Charles; Klitgaard, Kent; Krall, Lisi

2010-12-01

The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self-referential and narrowly rational way and that production can be described as a self-contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self-centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement. © 2010 Society for Conservation Biology.

DNA - peptide polyelectrolyte complexes: Phase control by hybridization

NASA Astrophysics Data System (ADS)

Vieregg, Jeffrey; Lueckheide, Michael; Marciel, Amanda; Leon, Lorraine; Tirrell, Matthew

DNA is one of the most highly-charged molecules known, and interacts strongly with charged molecules in the cell. Condensation of long double-stranded DNA is one of the classic problems of biophysics, but the polyelectrolyte behavior of short and/or single-stranded nucleic acids has attracted far less study despite its importance for both biological and engineered systems. We report here studies of DNA oligonucleotides complexed with cationic peptides and polyamines. As seen previously for longer sequences, double-stranded oligonucleotides form solid precipitates, but single-stranded oligonucleotides instead undergo liquid-liquid phase separation to form coacervate droplets. Complexed oligonucleotides remain competent for hybridization, and display sequence-dependent environmental response. We observe similar behavior for RNA oligonucleotides, and methylphosphonate substitution of the DNA backbone indicates that nucleic acid charge density controls whether liquid or solid complexes are formed. Liquid-liquid phase separations of this type have been implicated in formation of membraneless organelles in vivo, and have been suggested as protocells in early life scenarios; oligonucleotides offer an excellent method to probe the physics controlling these phenomena.

Physics of Ultrathin Films and Heterostructures of Rare-Earth Nickelates

DOE PAGES

Middey, Srimanta; Chakhalian, J.; Mahadevan, P.; ...

2016-04-06

The electronic structure of transition metal oxides featuring correlated electrons can be rationalized within the Zaanen-Sawatzky-Allen framework. Following a brief description of the present paradigms of electronic behavior, we focus on the physics of rare-earth nickelates as an archetype of complexity emerging within the charge transfer regime. The intriguing prospect of realizing the physics of high- Tc cuprates through heterostructuring resulted in a massive endeavor to epitaxially stabilize these materials in ultrathin form. A plethora of new phenomena unfolded in such artificial structures due to the effect of epitaxial strain, quantum confinement, and interfacial charge transfer. Here we review themore » present status of artificial rare-earth nickelates in an effort to uncover the interconnection between the electronic and magnetic behavior and the underlying crystal structure. Here, we conclude by discussing future directions to disentangle the puzzle regarding the origin of the metal-insulator transition, the role of oxygen holes, and the true nature of the antiferromagnetic spin configuration in the ultrathin limit.« less

A novel phenomenological multi-physics model of Li-ion battery cells

NASA Astrophysics Data System (ADS)

Oh, Ki-Yong; Samad, Nassim A.; Kim, Youngki; Siegel, Jason B.; Stefanopoulou, Anna G.; Epureanu, Bogdan I.

2016-09-01

A novel phenomenological multi-physics model of Lithium-ion battery cells is developed for control and state estimation purposes. The model can capture electrical, thermal, and mechanical behaviors of battery cells under constrained conditions, e.g., battery pack conditions. Specifically, the proposed model predicts the core and surface temperatures and reaction force induced from the volume change of battery cells because of electrochemically- and thermally-induced swelling. Moreover, the model incorporates the influences of changes in preload and ambient temperature on the force considering severe environmental conditions electrified vehicles face. Intensive experimental validation demonstrates that the proposed multi-physics model accurately predicts the surface temperature and reaction force for a wide operational range of preload and ambient temperature. This high fidelity model can be useful for more accurate and robust state of charge estimation considering the complex dynamic behaviors of the battery cell. Furthermore, the inherent simplicity of the mechanical measurements offers distinct advantages to improve the existing power and thermal management strategies for battery management.

Gaming, Adiposity, and Obesogenic Behaviors Among Children.

PubMed

Baranowski, Tom; Adamo, Kristi; Hingle, Melanie; Maddison, Ralph; Maloney, Ann; Simons, Monique; Staiano, Amanda

2013-06-01

Videogames in general have been maligned for causing obesity because of their inherent sedentariness, whereas exergames have been both maligned for requiring low levels of activity and extolled for requiring physical activity to move game play along. The intensity and duration of physical activity resulting from exergame play have shown varying results, and they have been explored for use in obesity treatment and prevention, primarily among children. Other videogames have been developed and tested to help children change their diet and physical activity practices with various outcomes. As a field of inquiry, we are in the earliest stages of understanding how, or under what circumstances, videogames can influence all these behavioral and health outcomes. To deal with these complexities, we have assembled a group of investigators who have made important, but diverse, contributions to this research agenda and asked them to address five key child obesity-related issues in a Roundtable format. Brief biosketches are presented at the end of this article.

Gaming, Adiposity, and Obesogenic Behaviors Among Children

PubMed Central

Baranowski, Moderator: Tom; Adamo, Participants: Kristi B.; Hingle, Melanie; Maddison, Ralph; Maloney, Ann; Simons, Monique; Staiano, Amanda

2013-01-01

Videogames in general have been maligned for causing obesity because of their inherent sedentariness, whereas exergames have been both maligned for requiring low levels of activity and extolled for requiring physical activity to move game play along. The intensity and duration of physical activity resulting from exergame play have shown varying results, and they have been explored for use in obesity treatment and prevention, primarily among children. Other videogames have been developed and tested to help children change their diet and physical activity practices with various outcomes. As a field of inquiry, we are in the earliest stages of understanding how, or under what circumstances, videogames can influence all these behavioral and health outcomes. To deal with these complexities, we have assembled a group of investigators who have made important, but diverse, contributions to this research agenda and asked them to address five key child obesity-related issues in a Roundtable format. Brief biosketches are presented at the end of this article. PMID:26196724

Fast Physically Accurate Rendering of Multimodal Signatures of Distributed Fracture in Heterogeneous Materials.

PubMed

Visell, Yon

2015-04-01

This paper proposes a fast, physically accurate method for synthesizing multimodal, acoustic and haptic, signatures of distributed fracture in quasi-brittle heterogeneous materials, such as wood, granular media, or other fiber composites. Fracture processes in these materials are challenging to simulate with existing methods, due to the prevalence of large numbers of disordered, quasi-random spatial degrees of freedom, representing the complex physical state of a sample over the geometric volume of interest. Here, I develop an algorithm for simulating such processes, building on a class of statistical lattice models of fracture that have been widely investigated in the physics literature. This algorithm is enabled through a recently published mathematical construction based on the inverse transform method of random number sampling. It yields a purely time domain stochastic jump process representing stress fluctuations in the medium. The latter can be readily extended by a mean field approximation that captures the averaged constitutive (stress-strain) behavior of the material. Numerical simulations and interactive examples demonstrate the ability of these algorithms to generate physically plausible acoustic and haptic signatures of fracture in complex, natural materials interactively at audio sampling rates.

Topics in Complexity: From Physical to Life Science Systems

NASA Astrophysics Data System (ADS)

Charry, Pedro David Manrique

Complexity seeks to unwrap the mechanisms responsible for collective phenomena across the physical, biological, chemical, economic and social sciences. This thesis investigates real-world complex dynamical systems ranging from the quantum/natural domain to the social domain. The following novel understandings are developed concerning these systems' out-of-equilibrium and nonlinear behavior. Standard quantum techniques show divergent outcomes when a quantum system comprising more than one subunit is far from thermodynamic equilibrium. Abnormal photon inter-arrival times help fulfill the metabolic needs of a terrestrial photosynthetic bacterium. Spatial correlations within incident light can act as a driving mechanism for an organism's adaptation toward more ordered structures. The group dynamics of non-identical objects, whose assembly rules depend on mutual heterogeneity, yield rich transition dynamics between isolation and cohesion, with the cohesion regime reproducing a particular universal pattern commonly found in many real-world systems. Analyses of covert networks reveal collective gender superiority in the connectivity that provides benefits for system robustness and survival. Nodal migration in a network generates complex contagion profiles that lie beyond traditional approaches and yet resemble many modern-day outbreaks.

A numerical study of coarsening in the two-dimensional complex Ginzburg-Landau equation

NASA Astrophysics Data System (ADS)

Liu, Weigang; Tauber, Uwe

The complex Ginzburg-Landau equation with additive noise is a stochastic partial differential equation that describes a remarkably wide range of physical systems: coupled non-linear oscillators subject to external noise near a Hopf bifurcation instability; spontaneous structure formation in non-equilibrium systems, e.g., in cyclically competing populations; and driven-dissipative Bose-Einstein condensation, realized in open systems on the interface of quantum optics and many-body physics. We employ a finite-difference method to numerically solve the noisy complex Ginzburg-Landau equation on a two-dimensional domain with the goal to investigate the coarsening dynamics following a quench from a strongly fluctuating defect turbulence phase to a long-range ordered phase. We start from a simplified amplitude equation, solve it numerically, and then study the spatio-temporal behavior characterized by the spontaneous creation and annihilation of topological defects (spiral waves). We check our simulation results against the known dynamical phase diagram in this non-equilibrium system, tentatively analyze the coarsening kinetics following sudden quenches, and characterize the ensuing aging scaling behavior. In addition, we aim to use Voronoi triangulation to study the cellular structure in the phase turbulence and frozen states. This research is supported by the U. S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering under Award DE-FG02-09ER46613.

Physical Therapy in the Treatment of Central Pain Mechanisms for Female Sexual Pain.

PubMed

Vandyken, Carolyn; Hilton, Sandra

2017-01-01

The complexity of female sexual pain requires an interdisciplinary approach. Physical therapists trained in pelvic health conditions are well positioned to be active members of an interdisciplinary team addressing the assessment and treatment of female sexual pain. Changes within physical therapy practice in the last ten years have resulted in significant utilization of pelvic floor muscle relaxation and manual therapy techniques to address a variety of pelvic pain conditions, including female sexual pain. However, sexual pain is a complex issue giving credence to the necessity of addressing all of the drivers of the pain experience- biological, psychological and social. This review aims to reconcile current pain science with a plan for integrating a biopsychosocial approach into the evaluation and subsequent treatment for female sexual pain for physical therapists. A literature review of the important components of skilled physical therapy interventions is presented including the physical examination, pain biology education, cognitive behavioral influences in treatment design, motivational interviewing as an adjunct to empathetic practice, and the integration of non-threatening movement and mindfulness into treatment. A single case study is used to demonstrate the biopsychosocial framework utilized in this approach. Appropriate measures for assessing psychosocial factors are readily available and inform a reasoned approach for physical therapy design that addresses both peripheral and central pain mechanisms. Decades of research support the integration of a biopsychosocial approach in the treatment of complex pain, including female sexual pain. It is reasonable for physical therapists to utilize evidence based strategies such as CBT, pain biology education, Mindfulness Based Stress Reduction (MBSR), yoga and imagery based exercises to address the biopsychosocial components of female sexual pain. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

The glassy random laser: replica symmetry breaking in the intensity fluctuations of emission spectra

PubMed Central

Antenucci, Fabrizio; Crisanti, Andrea; Leuzzi, Luca

2015-01-01

The behavior of a newly introduced overlap parameter, measuring the correlation between intensity fluctuations of waves in random media, is analyzed in different physical regimes, with varying amount of disorder and non-linearity. This order parameter allows to identify the laser transition in random media and describes its possible glassy nature in terms of emission spectra data, the only data so far accessible in random laser measurements. The theoretical analysis is performed in terms of the complex spherical spin-glass model, a statistical mechanical model describing the onset and the behavior of random lasers in open cavities. Replica Symmetry Breaking theory allows to discern different kinds of randomness in the high pumping regime, including the most complex and intriguing glassy randomness. The outcome of the theoretical study is, eventually, compared to recent intensity fluctuation overlap measurements demonstrating the validity of the theory and providing a straightforward interpretation of qualitatively different spectral behaviors in different random lasers. PMID:26616194

Comparison of Crack Initiation, Propagation and Coalescence Behavior of Concrete and Rock Materials

NASA Astrophysics Data System (ADS)

Zengin, Enes; Abiddin Erguler, Zeynal

2017-04-01

There are many previously studies carried out to identify crack initiation, propagation and coalescence behavior of different type of rocks. Most of these studies aimed to understand and predict the probable instabilities on different engineering structures such as mining galleries or tunnels. For this purpose, in these studies relatively smaller natural rock and synthetic rock-like models were prepared and then the required laboratory tests were performed to obtain their strength parameters. By using results provided from these models, researchers predicted the rock mass behavior under different conditions. However, in the most of these studies, rock materials and models were considered as contains none or very few discontinuities and structural flaws. It is well known that rock masses naturally are extremely complex with respect to their discontinuities conditions and thus it is sometimes very difficult to understand and model their physical and mechanical behavior. In addition, some vuggy rock materials such as basalts and limestones also contain voids and gaps having various geometric properties. Providing that the failure behavior of these type of rocks controlled by the crack initiation, propagation and coalescence formed from their natural voids and gaps, the effect of these voids and gaps over failure behavior of rocks should be investigated. Intact rocks are generally preferred due to relatively easy side of their homogeneous characteristics in numerical modelling phases. However, it is very hard to extract intact samples from vuggy rocks because of their complex pore sizes and distributions. In this study, the feasibility of concrete samples to model and mimic the failure behavior vuggy rocks was investigated. For this purpose, concrete samples were prepared at a mixture of %65 cement dust and %35 water and their physical and mechanical properties were determined by laboratory experiments. The obtained physical and mechanical properties were used to constitute numerical models, and then uniaxial compressive strength (UCS) tests were performed on these models by using a commercial software called as Particle Flow Code (PFC2D). When the crack behavior of concrete samples obtained from both laboratory tests and numerical models are compared with the results of previous studies, a significant similarity was found. As a result, due to the observed similarity crack behavior between concretes and rocks, it can be concluded that intact concrete samples can be used for modelling purposes to understand the effect of voids and gaps on failure characteristics of vuggy rocks.

Physics in ordered and disordered colloidal matter composed of poly(N-isopropylacrylamide) microgel particles.

PubMed

Yunker, Peter J; Chen, Ke; Gratale, Matthew D; Lohr, Matthew A; Still, Tim; Yodh, A G

2014-05-01

This review collects and describes experiments that employ colloidal suspensions to probe physics in ordered and disordered solids and related complex fluids. The unifying feature of this body of work is its clever usage of poly(N-isopropylacrylamide) (PNIPAM) microgel particles. These temperature-sensitive colloidal particles provide experimenters with a 'knob' for in situ control of particle size, particle interaction and particle packing fraction that, in turn, influence the structural and dynamical behavior of the complex fluids and solids. A brief summary of PNIPAM particle synthesis and properties is given, followed by a synopsis of current activity in the field. The latter discussion describes a variety of soft matter investigations including those that explore formation and melting of crystals and clusters, and those that probe structure, rearrangement and rheology of disordered (jammed/glassy) and partially ordered matter. The review, therefore, provides a snapshot of a broad range of physics phenomenology which benefits from the unique properties of responsive microgel particles.

Building Blocks for Reliable Complex Nonlinear Numerical Simulations

NASA Technical Reports Server (NTRS)

Yee, H. C.; Mansour, Nagi N. (Technical Monitor)

2002-01-01

This talk describes some of the building blocks to ensure a higher level of confidence in the predictability and reliability (PAR) of numerical simulation of multiscale complex nonlinear problems. The focus is on relating PAR of numerical simulations with complex nonlinear phenomena of numerics. To isolate sources of numerical uncertainties, the possible discrepancy between the chosen partial differential equation (PDE) model and the real physics and/or experimental data is set aside. The discussion is restricted to how well numerical schemes can mimic the solution behavior of the underlying PDE model for finite time steps and grid spacings. The situation is complicated by the fact that the available theory for the understanding of nonlinear behavior of numerics is not at a stage to fully analyze the nonlinear Euler and Navier-Stokes equations. The discussion is based on the knowledge gained for nonlinear model problems with known analytical solutions to identify and explain the possible sources and remedies of numerical uncertainties in practical computations. Examples relevant to turbulent flow computations are included.

Building Blocks for Reliable Complex Nonlinear Numerical Simulations

NASA Technical Reports Server (NTRS)

Yee, H. C.

2005-01-01

This chapter describes some of the building blocks to ensure a higher level of confidence in the predictability and reliability (PAR) of numerical simulation of multiscale complex nonlinear problems. The focus is on relating PAR of numerical simulations with complex nonlinear phenomena of numerics. To isolate sources of numerical uncertainties, the possible discrepancy between the chosen partial differential equation (PDE) model and the real physics and/or experimental data is set aside. The discussion is restricted to how well numerical schemes can mimic the solution behavior of the underlying PDE model for finite time steps and grid spacings. The situation is complicated by the fact that the available theory for the understanding of nonlinear behavior of numerics is not at a stage to fully analyze the nonlinear Euler and Navier-Stokes equations. The discussion is based on the knowledge gained for nonlinear model problems with known analytical solutions to identify and explain the possible sources and remedies of numerical uncertainties in practical computations.

Building Blocks for Reliable Complex Nonlinear Numerical Simulations. Chapter 2

NASA Technical Reports Server (NTRS)

Yee, H. C.; Mansour, Nagi N. (Technical Monitor)

2001-01-01

This chapter describes some of the building blocks to ensure a higher level of confidence in the predictability and reliability (PAR) of numerical simulation of multiscale complex nonlinear problems. The focus is on relating PAR of numerical simulations with complex nonlinear phenomena of numerics. To isolate sources of numerical uncertainties, the possible discrepancy between the chosen partial differential equation (PDE) model and the real physics and/or experimental data is set aside. The discussion is restricted to how well numerical schemes can mimic the solution behavior of the underlying PDE model for finite time steps and grid spacings. The situation is complicated by the fact that the available theory for the understanding of nonlinear behavior of numerics is not at a stage to fully analyze the nonlinear Euler and Navier-Stokes equations. The discussion is based on the knowledge gained for nonlinear model problems with known analytical solutions to identify and explain the possible sources and remedies of numerical uncertainties in practical computations. Examples relevant to turbulent flow computations are included.

A network approach to discerning the identities of C. elegans in a free moving population

NASA Astrophysics Data System (ADS)

Winter, Peter B.; Brielmann, Renee M.; Timkovich, Nicholas P.; Navarro, Helio T.; Teixeira-Castro, Andreia; Morimoto, Richard I.; Amaral, Luis A. N.

2016-10-01

The study of C. elegans has led to ground-breaking discoveries in gene-function, neuronal circuits, and physiological responses. Subtle behavioral phenotypes, however, are often difficult to measure reproducibly. We have developed an experimental and computational infrastructure to simultaneously record and analyze the physical characteristics, movement, and social behaviors of dozens of interacting free-moving nematodes. Our algorithm implements a directed acyclic network that reconstructs the complex behavioral trajectories generated by individual C. elegans in a free moving population by chaining hundreds to thousands of short tracks into long contiguous trails. This technique allows for the high-throughput quantification of behavioral characteristics that require long-term observation of individual animals. The graphical interface we developed will enable researchers to uncover, in a reproducible manner, subtle time-dependent behavioral phenotypes that will allow dissection of the molecular mechanisms that give rise to organism-level behavior.

Laban Movement Analysis towards Behavior Patterns

NASA Astrophysics Data System (ADS)

Santos, Luís; Dias, Jorge

This work presents a study about the use of Laban Movement Analysis (LMA) as a robust tool to describe human basic behavior patterns, to be applied in human-machine interaction. LMA is a language used to describe and annotate dancing movements and is divided in components [1]: Body, Space, Shape and Effort. Despite its general framework is widely used in physical and mental therapy [2], it has found little application in the engineering domain. Rett J. [3] proposed to implement LMA using Bayesian Networks. However LMA component models have not yet been fully implemented. A study on how to approach behavior using LMA is presented. Behavior is a complex feature and movement chain, but we believe that most basic behavior primitives can be discretized in simple features. Correctly identifying Laban parameters and the movements the authors feel that good patterns can be found within a specific set of basic behavior semantics.

Scale Invariance in Lateral Head Scans During Spatial Exploration.

PubMed

Yadav, Chetan K; Doreswamy, Yoganarasimha

2017-04-14

Universality connects various natural phenomena through physical principles governing their dynamics, and has provided broadly accepted answers to many complex questions, including information processing in neuronal systems. However, its significance in behavioral systems is still elusive. Lateral head scanning (LHS) behavior in rodents might contribute to spatial navigation by actively managing (optimizing) the available sensory information. Our findings of scale invariant distributions in LHS lifetimes, interevent intervals and event magnitudes, provide evidence for the first time that the optimization takes place at a critical point in LHS dynamics. We propose that the LHS behavior is responsible for preprocessing of the spatial information content, critical for subsequent foolproof encoding by the respective downstream neural networks.

Scale Invariance in Lateral Head Scans During Spatial Exploration

NASA Astrophysics Data System (ADS)

Yadav, Chetan K.; Doreswamy, Yoganarasimha

2017-04-01

Universality connects various natural phenomena through physical principles governing their dynamics, and has provided broadly accepted answers to many complex questions, including information processing in neuronal systems. However, its significance in behavioral systems is still elusive. Lateral head scanning (LHS) behavior in rodents might contribute to spatial navigation by actively managing (optimizing) the available sensory information. Our findings of scale invariant distributions in LHS lifetimes, interevent intervals and event magnitudes, provide evidence for the first time that the optimization takes place at a critical point in LHS dynamics. We propose that the LHS behavior is responsible for preprocessing of the spatial information content, critical for subsequent foolproof encoding by the respective downstream neural networks.

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model.

PubMed

Solares, Santiago D

2014-01-01

This paper presents computational simulations of single-mode and bimodal atomic force microscopy (AFM) with particular focus on the viscoelastic interactions occurring during tip-sample impact. The surface is modeled by using a standard linear solid model, which is the simplest system that can reproduce creep compliance and stress relaxation, which are fundamental behaviors exhibited by viscoelastic surfaces. The relaxation of the surface in combination with the complexities of bimodal tip-sample impacts gives rise to unique dynamic behaviors that have important consequences with regards to the acquisition of quantitative relationships between the sample properties and the AFM observables. The physics of the tip-sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided.

Self-Regulation in the Midst of Complexity: A Case Study of High School Physics Students Engaged in Ill-Structured Problem Solving

NASA Astrophysics Data System (ADS)

Milbourne, Jeffrey David

The purpose of this dissertation study was to explore the experiences of high school physics students who were solving complex, ill-structured problems, in an effort to better understand how self-regulatory behavior mediated the project experience. Consistent with Voss, Green, Post, and Penner's (1983) conception of an ill-structured problem in the natural sciences, the 'problems' consisted of scientific research projects that students completed under the supervision of a faculty mentor. Zimmerman and Campillo's (2003) self-regulatory framework of problem solving provided a holistic guide to data collection and analysis of this multi-case study, with five individual student cases. The study's results are explored in two manuscripts, each targeting a different audience. The first manuscript, intended for the Science Education Research community, presents a thick, rich description of the students' project experiences, consistent with a qualitative, case study analysis. Findings suggest that intrinsic interest was an important self-regulatory factor that helped motivate students throughout their project work, and that the self-regulatory cycle of forethought, performance monitoring, and self-reflection was an important component of the problem-solving process. Findings also support the application of Zimmerman and Campillo's framework to complex, ill-structured problems, particularly the cyclical nature of the framework. Finally, this study suggests that scientific research projects, with the appropriate support, can be a mechanism for improving students' selfregulatory behavior. The second manuscript, intended for Physics practitioners, combines the findings of the first manuscript with the perspectives of the primary, on-site research mentor, who has over a decade's worth of experience mentoring students doing physics research. His experience suggests that a successful research experience requires certain characteristics, including: a slow, 'on-ramp' to the research experience, space to experience productive failure, and an opportunity to enjoy the work they are doing.

The physical hydrogeology of ore deposits

USGS Publications Warehouse

Ingebritsen, Steven E.; Appold, M.S.

2012-01-01

Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

Ice Storm Supercomputer

ScienceCinema

None

2018-05-01

A new Idaho National Laboratory supercomputer is helping scientists create more realistic simulations of nuclear fuel. Dubbed "Ice Storm" this 2048-processor machine allows researchers to model and predict the complex physics behind nuclear reactor behavior. And with a new visualization lab, the team can see the results of its simulations on the big screen. For more information about INL research, visit http://www.facebook.com/idahonationallaboratory.

Perceptual-Cognitive Changes During Motor Learning: The Influence of Mental and Physical Practice on Mental Representation, Gaze Behavior, and Performance of a Complex Action

PubMed Central

Frank, Cornelia; Land, William M.; Schack, Thomas

2016-01-01

Despite the wealth of research on differences between experts and novices with respect to their perceptual-cognitive background (e.g., mental representations, gaze behavior), little is known about the change of these perceptual-cognitive components over the course of motor learning. In the present study, changes in one’s mental representation, quiet eye behavior, and outcome performance were examined over the course of skill acquisition as it related to physical and mental practice. Novices (N = 45) were assigned to one of three conditions: physical practice, combined physical plus mental practice, and no practice. Participants in the practice groups trained on a golf putting task over the course of 3 days, either by repeatedly executing the putt, or by both executing and imaging the putt. Findings revealed improvements in putting performance across both practice conditions. Regarding the perceptual-cognitive changes, participants practicing mentally and physically revealed longer quiet eye durations as well as more elaborate representation structures in comparison to the control group, while this was not the case for participants who underwent physical practice only. Thus, in the present study, combined mental and physical practice led to both formation of mental representations in long-term memory and longer quiet eye durations. Interestingly, the length of the quiet eye directly related to the degree of elaborateness of the underlying mental representation, supporting the notion that the quiet eye reflects cognitive processing. This study is the first to show that the quiet eye becomes longer in novices practicing a motor action. Moreover, the findings of the present study suggest that perceptual and cognitive adaptations co-occur over the course of motor learning. PMID:26779089

Enhancing personal agency and competence in eating and moving: formative evaluation of a middle school curriculum--Choice, Control, and Change.

PubMed

Contento, Isobel R; Koch, Pamela A; Lee, Heewon; Sauberli, Wendy; Calabrese-Barton, Angela

2007-01-01

The purpose of this formative evaluation was to examine the impact of an innovative inquiry-based science education curriculum for middle school students, called Choice, Control, and Change, that is designed to foster healthful eating and physical activity and a healthy weight through enhancing agency and competence. The 24-session curriculum helps students develop understandings about the interactions between biology, personal behavior, and the environment and personal agency through cognitive self-regulation skills in navigating today's complex food system and sedentary environment. An extended theory of planned behavior served as the design framework. The study used a pretest-posttest evaluation design involving 278 middle school students in 19 science classes within 5 schools. Based on paired t tests, students significantly improved on several curriculum-specific eating and physical activity behaviors: they decreased several sedentary activities and increased their frequencies of fruit and vegetable intake. They decreased the frequency of sweetened beverages, packaged snacks, and eating at a fast-food restaurant, and ate and drank smaller portions of some items. Their outcome beliefs and overall self-efficacy, but not their attitudes, became more positive. A strategy based on fostering personal agency, cognitive self-regulation, and competence can be effective in increasing healthful eating and physical activity behaviors in middle school children and should be explored further.

Robustness of critical points in a complex adaptive system: Effects of hedge behavior

NASA Astrophysics Data System (ADS)

Liang, Yuan; Huang, Ji-Ping

2013-08-01

In our recent papers, we have identified a class of phase transitions in the market-directed resource-allocation game, and found that there exists a critical point at which the phase transitions occur. The critical point is given by a certain resource ratio. Here, by performing computer simulations and theoretical analysis, we report that the critical point is robust against various kinds of human hedge behavior where the numbers of herds and contrarians can be varied widely. This means that the critical point can be independent of the total number of participants composed of normal agents, herds and contrarians, under some conditions. This finding means that the critical points we identified in this complex adaptive system (with adaptive agents) may also be an intensive quantity, similar to those revealed in traditional physical systems (with non-adaptive units).

Creative strategies of businesses with the holistic eigensolution in manufacturing industries

NASA Astrophysics Data System (ADS)

Zeichen, Gerfried; Huray, Paul G.

1998-10-01

It is a mission of this contribution to recognize and synthesize all the efforts in industry and in management science to strengthen our techniques and tools for successfully solving increasingly complex leadership problems in manufacturing industries. With the high standard of the work sharing method--the so called Taylorism principle--for cost efficient and mass production, invented at the beginning of the 20th century and the opening of the world market for global sales of goods and services a gigantic progress in living standards was reached. But at the beginning of the 21st century we are needing new ideas and methods for the guidance of overcoming increasing complexity. The holistic eigensolution presents a new operational framework for viewing and controlling the behavior of businesses. In contrast to the traditional process for viewing complex business systems through the intricate analysis of every part of that system, the authors have employed a technique used by physicists to understand the characteristic of `eigen' behaviors of complex physical systems. This method of systems analysis is achieved by observing interactions between the parts in a whole. This kind of analysis has a rigorous mathematical foundation in the physical world and it can be employed to understand most natural phenomena. Within a holistic framework, the observer is challenged to view the system form just the right perspective so that characteristic eigenmodes reveal themselves. The conclusion of the article describes why exactly the intelligent manufacturing science--especially in a broader sense--has the responsibility and chance to develop the holistic eigensolution framework as a Taylorism II-principle for the 21st century.

Physical principles for DNA tile self-assembly.

PubMed

Evans, Constantine G; Winfree, Erik

2017-06-19

DNA tiles provide a promising technique for assembling structures with nanoscale resolution through self-assembly by basic interactions rather than top-down assembly of individual structures. Tile systems can be programmed to grow based on logical rules, allowing for a small number of tile types to assemble large, complex assemblies that can retain nanoscale resolution. Such algorithmic systems can even assemble different structures using the same tiles, based on inputs that seed the growth. While programming and theoretical analysis of tile self-assembly often makes use of abstract logical models of growth, experimentally implemented systems are governed by nanoscale physical processes that can lead to very different behavior, more accurately modeled by taking into account the thermodynamics and kinetics of tile attachment and detachment in solution. This review discusses the relationships between more abstract and more physically realistic tile assembly models. A central concern is how consideration of model differences enables the design of tile systems that robustly exhibit the desired abstract behavior in realistic physical models and in experimental implementations. Conversely, we identify situations where self-assembly in abstract models can not be well-approximated by physically realistic models, putting constraints on physical relevance of the abstract models. To facilitate the discussion, we introduce a unified model of tile self-assembly that clarifies the relationships between several well-studied models in the literature. Throughout, we highlight open questions regarding the physical principles for DNA tile self-assembly.

Automated Design of Complex Dynamic Systems

PubMed Central

Hermans, Michiel; Schrauwen, Benjamin; Bienstman, Peter; Dambre, Joni

2014-01-01

Several fields of study are concerned with uniting the concept of computation with that of the design of physical systems. For example, a recent trend in robotics is to design robots in such a way that they require a minimal control effort. Another example is found in the domain of photonics, where recent efforts try to benefit directly from the complex nonlinear dynamics to achieve more efficient signal processing. The underlying goal of these and similar research efforts is to internalize a large part of the necessary computations within the physical system itself by exploiting its inherent non-linear dynamics. This, however, often requires the optimization of large numbers of system parameters, related to both the system's structure as well as its material properties. In addition, many of these parameters are subject to fabrication variability or to variations through time. In this paper we apply a machine learning algorithm to optimize physical dynamic systems. We show that such algorithms, which are normally applied on abstract computational entities, can be extended to the field of differential equations and used to optimize an associated set of parameters which determine their behavior. We show that machine learning training methodologies are highly useful in designing robust systems, and we provide a set of both simple and complex examples using models of physical dynamical systems. Interestingly, the derived optimization method is intimately related to direct collocation a method known in the field of optimal control. Our work suggests that the application domains of both machine learning and optimal control have a largely unexplored overlapping area which envelopes a novel design methodology of smart and highly complex physical systems. PMID:24497969

Modeling Composite Laminate Crushing for Crash Analysis

NASA Technical Reports Server (NTRS)

Fleming, David C.; Jones, Lisa (Technical Monitor)

2002-01-01

Crash modeling of composite structures remains limited in application and has not been effectively demonstrated as a predictive tool. While the global response of composite structures may be well modeled, when composite structures act as energy-absorbing members through direct laminate crushing the modeling accuracy is greatly reduced. The most efficient composite energy absorbing structures, in terms of energy absorbed per unit mass, are those that absorb energy through a complex progressive crushing response in which fiber and matrix fractures on a small scale dominate the behavior. Such failure modes simultaneously include delamination of plies, failure of the matrix to produce fiber bundles, and subsequent failure of fiber bundles either in bending or in shear. In addition, the response may include the significant action of friction, both internally (between delaminated plies or fiber bundles) or externally (between the laminate and the crushing surface). A figure shows the crushing damage observed in a fiberglass composite tube specimen, illustrating the complexity of the response. To achieve a finite element model of such complex behavior is an extremely challenging problem. A practical crushing model based on detailed modeling of the physical mechanisms of crushing behavior is not expected in the foreseeable future. The present research describes attempts to model composite crushing behavior using a novel hybrid modeling procedure. Experimental testing is done is support of the modeling efforts, and a test specimen is developed to provide data for validating laminate crushing models.

Complexation of Polyelectrolytes with Hydrophobic Drug Molecules in Salt-Free Solution: Theory and Simulations.

PubMed

Lei, Qun-Li; Hadinoto, Kunn; Ni, Ran

2017-04-18

The delivery and dissolution of poorly soluble drugs is challenging in the pharmaceutical industry. One way to significantly improve the delivery efficiency is to incorporate these hydrophobic small molecules into a colloidal polyelectrolyes(PE)-drug complex in their ionized states. Despite its huge application value, the general mechanism of PE collapse and complex formation in this system has not been well understood. In this work, by combining a mean-field theory with extensive molecular simulations, we unveil the phase behaviors of the system under dilute and salt-free conditions. We find that the complexation is a first-order-like phase transition triggered by the hydrophobic attraction between the drug molecules. Importantly, the valence ratio between the drug molecule and PE monomer plays a crucial role in determining the stability and morphology of the complex. Moreover, the sign of the zeta potential and the net charge of the complex are found to be inverted as the hydrophobicity of the drug molecules increases. Both theory and simulation indicate that the complexation point and complex morphology and the electrostatic properties of the complex have a weak dependence on chain length. Finally, the dynamics aspect of PE-drug complexation is also explored, and it is found that the complex can be trapped into a nonequilibrium glasslike state when the hydropobicity of the drug molecule is too strong. Our work gives a clear physical picture behind the PE-drug complexation phenomenon and provides guidelines to fabricate the colloidal PE-drug complex with the desired physical characteristics.

Turbulent pipe flow at extreme Reynolds numbers.

PubMed

Hultmark, M; Vallikivi, M; Bailey, S C C; Smits, A J

2012-03-02

Both the inherent intractability and complex beauty of turbulence reside in its large range of physical and temporal scales. This range of scales is captured by the Reynolds number, which in nature and in many engineering applications can be as large as 10(5)-10(6). Here, we report turbulence measurements over an unprecedented range of Reynolds numbers using a unique combination of a high-pressure air facility and a new nanoscale anemometry probe. The results reveal previously unknown universal scaling behavior for the turbulent velocity fluctuations, which is remarkably similar to the well-known scaling behavior of the mean velocity distribution.

Robot, computer problem solving system

NASA Technical Reports Server (NTRS)

Becker, J. D.

1972-01-01

The development of a computer problem solving system is reported that considers physical problems faced by an artificial robot moving around in a complex environment. Fundamental interaction constraints with a real environment are simulated for the robot by visual scan and creation of an internal environmental model. The programming system used in constructing the problem solving system for the simulated robot and its simulated world environment is outlined together with the task that the system is capable of performing. A very general framework for understanding the relationship between an observed behavior and an adequate description of that behavior is included.

A Study on Contingency Learning in Introductory Physics Concepts

NASA Astrophysics Data System (ADS)

Scaife, Thomas M.

Instructors of physics often use examples to illustrate new or complex physical concepts to students. For any particular concept, there are an infinite number of examples, thus presenting instructors with a difficult question whenever they wish to use one in their teaching: which example will most effectively illustrate the concept so that student learning is maximized? The choice is typically made by an intuitive assumption about which exact example will result in the most lucid illustration and the greatest student improvement. By questioning 583 students in four experiments, I examined a more principled approach to example selection. By controlling the manner in which physical dimensions vary, the parameter space of each concept can be divided into a discrete number of example categories. The effects of training with members of each of category was explored in two different physical contexts: projectile motion and torque. In the first context, students were shown two trajectories and asked to determine which represented the longer time of flight. Height, range, and time of flight were the physical dimensions that were used to categorize the examples. In the second context, students were shown a balance-scale with loads of differing masses placed at differing positions along either side of the balance-arm. Mass, lever-arm length, and torque were the physical dimensions used to categorize these examples. For both contexts, examples were chosen so that one or two independent dimensions were varied. After receiving training with examples from specific categories, students were tested with questions from all question categories. Successful training or instruction can be measured either as producing correct, expert-like behavior (as observed through answers to the questions) or as explicitly instilling an understanding of the underlying rule that governs a physical phenomenon. A student's behavior might not be consistent with their explicit rule, so following the investigation of their behavior, students were asked what rule they used when answering questions. Although the self-reported rules might not be congruent with their behavior, training with specific examples might affect how students explicitly think about physics problems. In addition to exploring the effectiveness of various training examples, the results were also compared to a cognitive theory of causality: the contingency model. Physical concepts can often be expressed in terms of causal relations (e.g., a net force causes an object to accelerate), and a large body of work has found that people make many decisions that are consistent with causal reasoning. The contingency model, in particular, explains how certain statistical regularities in the co-occurrence of two events can be interpreted by individuals as causal relations, and was chosen primarily because it of its robust results and simple, parsimonious form. The empirical results demonstrate that different categories of training examples did affect student answers differently. Furthermore, these effects were mostly consistent with the predictions made by the contingency model. When rule use was explored, the self-reported rules were consistent with contingency model predictions, but indicated that examples alone were insufficient to teach complex functional relationships between physical dimensions, such as torque.

Do work relationships matter? Characteristics of workplace interactions that enhance or detract from employee perceptions of well-being and health behaviors.

PubMed

Mastroianni, Karen; Storberg-Walker, Julia

2014-01-01

This qualitative case study adopted the position that health and health behaviors are complex social constructs influenced by multiple factors. Framed by the social ecological model, the study explored how work interactions enhanced or detracted from the perceptions of well-being and health behaviors. Despite the fact that previous studies indicated that the social workplace environment contributed to employee health, there was little information regarding the characteristics. Specifically, little was known about how employees perceived the connections between workplace interactions and health, or how social interactions enhanced or detracted from well-being and health behaviors. The participants included 19 volunteers recruited from four companies, who shared their experiences of workplace interactions through interviews and journaling assignments. The findings indicated that feelings of well-being were enhanced by work interactions, which were trusting, collaborative, and positive, as well as when participants felt valued and respected. The study also found that interactions detracted from well-being and health behaviors when interactions lacked the aforementioned characteristics, and also included lack of justice and empathy. The enhancing and detracting relationships generated physical symptoms, and influenced sleeping and eating patterns, socializing, exercise, personal relations, careers, and energy. Surprisingly, the study found that regardless of how broadly participants defined health, when they were asked to rate their health, participants uniformly rated theirs on physical attributes alone. The exclusive consideration of physical attributes suggests that participants may have unconsciously adopted the typical western medical view of health - an individually determined and physiologic characteristic. Despite research suggesting health is more than biology, and despite defining health broadly, participants uniformly adopted this traditional view. The study also offers human resource development professionals with evidence supporting interventions aimed at minimizing workplace incivility. Interventions designed to improve employee engagement could minimize financial and human costs of negative interactions. The bottom line is that workplaces should be physically, emotionally, and psychologically safe for well-being and healthy behaviors to flourish.

Do work relationships matter? Characteristics of workplace interactions that enhance or detract from employee perceptions of well-being and health behaviors

PubMed Central

Mastroianni, Karen; Storberg-Walker, Julia

2014-01-01

This qualitative case study adopted the position that health and health behaviors are complex social constructs influenced by multiple factors. Framed by the social ecological model, the study explored how work interactions enhanced or detracted from the perceptions of well-being and health behaviors. Despite the fact that previous studies indicated that the social workplace environment contributed to employee health, there was little information regarding the characteristics. Specifically, little was known about how employees perceived the connections between workplace interactions and health, or how social interactions enhanced or detracted from well-being and health behaviors. The participants included 19 volunteers recruited from four companies, who shared their experiences of workplace interactions through interviews and journaling assignments. The findings indicated that feelings of well-being were enhanced by work interactions, which were trusting, collaborative, and positive, as well as when participants felt valued and respected. The study also found that interactions detracted from well-being and health behaviors when interactions lacked the aforementioned characteristics, and also included lack of justice and empathy. The enhancing and detracting relationships generated physical symptoms, and influenced sleeping and eating patterns, socializing, exercise, personal relations, careers, and energy. Surprisingly, the study found that regardless of how broadly participants defined health, when they were asked to rate their health, participants uniformly rated theirs on physical attributes alone. The exclusive consideration of physical attributes suggests that participants may have unconsciously adopted the typical western medical view of health – an individually determined and physiologic characteristic. Despite research suggesting health is more than biology, and despite defining health broadly, participants uniformly adopted this traditional view. The study also offers human resource development professionals with evidence supporting interventions aimed at minimizing workplace incivility. Interventions designed to improve employee engagement could minimize financial and human costs of negative interactions. The bottom line is that workplaces should be physically, emotionally, and psychologically safe for well-being and healthy behaviors to flourish. PMID:25750820

Anatomy and physiology of the liver in relation to clinical assessment.

PubMed

Pierce, L

1977-06-01

As nurses assume expanded roles in patient care, skills in history-taking and in performing a physical examination are expected. Of the various diagnostic procedures the history and physical examination are the most direct and expeditious methods of obtaining facts about patients' problems. As represented in this article, detailed knowledge of the liver's anatomy and physiology as well as that of other body systems is prerequisite to these skills. To understand and document the complexity of life disturbances occuring in patients with hepatic problems, integration of social-behavioral and mental health concepts is needed.

The theory of expanded, extended, and enhanced opportunities for youth physical activity promotion.

PubMed

Beets, Michael W; Okely, Anthony; Weaver, R Glenn; Webster, Collin; Lubans, David; Brusseau, Tim; Carson, Russ; Cliff, Dylan P

2016-11-16

Physical activity interventions targeting children and adolescents (≤18 years) often focus on complex intra- and inter-personal behavioral constructs, social-ecological frameworks, or some combination of both. Recently published meta-analytical reviews and large-scale randomized controlled trials have demonstrated that these intervention approaches have largely produced minimal or no improvements in young people's physical activity levels. In this paper, we propose that the main reason for previous studies' limited effects is that fundamental mechanisms that lead to change in youth physical activity have often been overlooked or misunderstood. Evidence from observational and experimental studies is presented to support the development of a new theory positing that the primary mechanisms of change in many youth physical activity interventions are approaches that fall into one of the following three categories: (a) the expansion of opportunities for youth to be active by the inclusion of a new occasion to be active, (b) the extension of an existing physical activity opportunity by increasing the amount of time allocated for that opportunity, and/or (c) the enhancement of existing physical activity opportunities through strategies designed to increase physical activity above routine practice. Their application and considerations for intervention design and interpretation are presented. The utility of these mechanisms, referred to as the Theory of Expanded, Extended, and Enhanced Opportunities (TEO), is demonstrated in their parsimony, logical appeal, support with empirical evidence, and the direct and immediate application to numerous settings and contexts. The TEO offers a new way to understand youth physical activity behaviors and provides a common taxonomy by which interventionists can identify appropriate targets for interventions across different settings and contexts. We believe the formalization of the TEO concepts will propel them to the forefront in the design of future intervention studies and through their use, lead to a greater impact on youth activity behaviors than what has been demonstrated in previous studies.

Thermal dynamic behavior during selective laser melting of K418 superalloy: numerical simulation and experimental verification

NASA Astrophysics Data System (ADS)

Chen, Zhen; Xiang, Yu; Wei, Zhengying; Wei, Pei; Lu, Bingheng; Zhang, Lijuan; Du, Jun

2018-04-01

During selective laser melting (SLM) of K418 powder, the influence of the process parameters, such as laser power P and scanning speed v, on the dynamic thermal behavior and morphology of the melted tracks was investigated numerically. A 3D finite difference method was established to predict the dynamic thermal behavior and flow mechanism of K418 powder irradiated by a Gaussian laser beam. A three-dimensional randomly packed powder bed composed of spherical particles was established by discrete element method. The powder particle information including particle size distribution and packing density were taken into account. The volume shrinkage and temperature-dependent thermophysical parameters such as thermal conductivity, specific heat, and other physical properties were also considered. The volume of fluid method was applied to reconstruct the free surface of the molten pool during SLM. The geometrical features, continuity boundaries, and irregularities of the molten pool were proved to be largely determined by the laser energy density. The numerical results are in good agreement with the experiments, which prove to be reasonable and effective. The results provide us some in-depth insight into the complex physical behavior during SLM and guide the optimization of process parameters.

In-memory integration of existing software components for parallel adaptive unstructured mesh workflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Cameron W.; Granzow, Brian; Diamond, Gerrett

Unstructured mesh methods, like finite elements and finite volumes, support the effective analysis of complex physical behaviors modeled by partial differential equations over general threedimensional domains. The most reliable and efficient methods apply adaptive procedures with a-posteriori error estimators that indicate where and how the mesh is to be modified. Although adaptive meshes can have two to three orders of magnitude fewer elements than a more uniform mesh for the same level of accuracy, there are many complex simulations where the meshes required are so large that they can only be solved on massively parallel systems.

In-memory integration of existing software components for parallel adaptive unstructured mesh workflows

DOE PAGES

Smith, Cameron W.; Granzow, Brian; Diamond, Gerrett; ...

2017-01-01

Unstructured mesh methods, like finite elements and finite volumes, support the effective analysis of complex physical behaviors modeled by partial differential equations over general threedimensional domains. The most reliable and efficient methods apply adaptive procedures with a-posteriori error estimators that indicate where and how the mesh is to be modified. Although adaptive meshes can have two to three orders of magnitude fewer elements than a more uniform mesh for the same level of accuracy, there are many complex simulations where the meshes required are so large that they can only be solved on massively parallel systems.

Effect of Nonlinear Gradient Terms on Breathing Localized Solutions in the Quintic Complex Ginzburg-Landau Equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deissler, R.J.; Brand, H.R.; Deissler, R.J.

1998-11-01

We study the effect of nonlinear gradient terms on breathing localized solutions in the complex Ginzburg-Landau equation. It is found that even small nonlinear gradient terms{emdash}which appear at the same order as the quintic term{emdash}can cause dramatic changes in the behavior of the solution, such as causing opposite sides of an otherwise monoperiodic symmetrically breathing solution to breathe at different frequencies, thus causing the solution to breathe periodically or chaotically on only one side or the solution to rapidly spread. {copyright} {ital 1998} {ital The American Physical Society }

Complex contribution of combat-related post-traumatic stress disorder to veteran suicide: facing an increasing challenge.

PubMed

Lee, Elizabeth A D

2012-04-01

The purpose of this case study is to present the complex contribution of combat-related post-traumatic stress disorder (PTSD) to suicide and international standards of treatment among veterans deployed to the Middle East. PTSD carries increased physical and psychological health risk in combat soldiers. Internationally, guidelines for PTSD promote cognitive behavior therapies, specifically exposure therapy, as first line treatment; however, implementation varies among countries. Evidence supports the benefit of exposure-based psychotherapy for combat-related PTSD. Commonly prescribed antidepressants and other psychotherapy treatments may not be as beneficial. © 2011 Wiley Periodicals, Inc.

Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui

Development of new generation electronic devices requires understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation ofmore » the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite–cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Finally and furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching.« less

Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures

DOE PAGES

Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui; ...

2015-08-27

Development of new generation electronic devices requires understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation ofmore » the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite–cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Finally and furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching.« less

Physical Activity, Sedentary Habits, Sleep, and Obesity are Associated with Asthma, Allergic Rhinitis, and Atopic Dermatitis in Korean Adolescents.

PubMed

Lim, Man Sup; Lee, Chang Hee; Sim, Songyong; Hong, Sung Kwang; Choi, Hyo Geun

2017-09-01

Since pathophysiologic evidence has been raised to suggest that obesity could facilitate an allergic reaction, obesity has been known as an independent risk factor for allergic disease such as asthma. However, the relationship between sedentary behavior and lifestyle which could lead to obesity, and those allergic diseases remains unclear. We analyzed the relations between physical activity, including sitting time for study, sitting time for leisure and sleep time, and obesity, asthma, allergic rhinitis, and atopic dermatitis using the Korea Youth Risk Behavior Web-based Survey, which was conducted in 2013. Total 53769 adolescent participants (12 through 18 years old) were analyzed using simple and multiple logistic regression analyses with complex sampling. Longer sitting time for study and short sitting time for leisure were associated with allergic rhinitis. High physical activity and short sleep time were associated with asthma, allergic rhinitis, and atopic dermatitis. Underweight was negatively associated with atopic dermatitis, whereas overweight was positively correlated with allergic rhinitis and atopic dermatitis. High physical activity, and short sleep time were associated with asthma, allergic rhinitis, and atopic dermatitis. © Copyright: Yonsei University College of Medicine 2017

Applied Cognitive Models of Behavior and Errors Patterns

DTIC Science & Technology

2017-09-01

methods offer an opportunity to deliver good , effective introductory and basic training , thus potentially enabling a single human instructor to train ...emergency medical technician (EMT) domain, which offers a standardized curriculum on which we can create training scenarios. 2. Develop...complexity of software integration and limited access to physical devices can result in commitment to a de- sign that turns out to not offer many training

Association between physical activity and kidney function: National Health and Nutrition Examination Survey.

PubMed

Hawkins, Marquis S; Sevick, Mary Ann; Richardson, Caroline R; Fried, Linda F; Arena, Vincent C; Kriska, Andrea M

2011-08-01

Chronic kidney disease is a condition characterized by the deterioration of the kidney's ability to remove waste products from the body. Although treatments to slow the progression of the disease are available, chronic kidney disease may eventually lead to a complete loss of kidney function. Previous studies have shown that physical activities of moderate intensity may have renal benefits. Few studies have examined the effects of total movement on kidney function. The purpose of this study was to determine the association between time spent at all levels of physical activity intensity and sedentary behavior and kidney function. Data were obtained from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey, a cross-sectional study of a complex, multistage probability sample of the US population. Physical activity was assessed using an accelerometer and questionnaire. Glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease study formula. To assess linear associations between levels of physical activity and sedentary behavior with log-transformed estimated GFR (eGFR), linear regression was used. In general, physical activity (light and total) was related to log eGFR in females and males. For females, the association between light and total physical activity with log eGFR was consistent regardless of diabetes status. For males, the association between light and total physical activity and log eGFR was only significant in males without diabetes. When examining the association between physical activity, measured objectively with an accelerometer, and kidney function, total and light physical activities were found to be positively associated with kidney function.

Using Community Insight to Understand Physical Activity Adoption in Overweight and Obese African American and Hispanic Women: A Qualitative Study

PubMed Central

Mama, Scherezade K.; McCurdy, Sheryl A.; Evans, Alexandra E.; Thompson, Deborah I.; Diamond, Pamela M.; Lee, Rebecca E.

2015-01-01

Ecologic models suggest that multiple levels of influencing factors are important for determining physical activity participation and include individual, social, and environmental factors. The purpose of this qualitative study was to use an ecologic framework to gain a deeper understanding of the underlying behavioral mechanisms that influence physical activity adoption among ethnic minority women. Eighteen African American and Hispanic women completed a 1-hour in-depth interview. Verbatim interview transcripts were analyzed for emergent themes using a constant comparison approach. Women were middle-aged (age M = 43.9 ± 7.3 years), obese (body mass index M = 35.0 ± 8.9 kg/m2), and of high socioeconomic status (88.9% completed some college or more, 41.2% reported income >$82,600/year). Participants discussed individual factors, including the need for confidence, motivation and time, and emphasized the importance of environmental factors, including their physical neighborhood environments and safety of and accessibility to physical activity resources. Women talked about caretaking for others and social support and how these influenced physical activity behavior. The findings from this study highlight the multilevel, interactive complexities that influence physical activity, emphasizing the need for a more sophisticated, ecologic approach for increasing physical activity adoption and maintenance among ethnic minority women. Community insight gleaned from this study may be used to better understand determinants of physical activity and develop multilevel solutions and programs guided by an ecologic framework to increase physical activity in ethnic minority women. PMID:25504569

Using community insight to understand physical activity adoption in overweight and obese African American and Hispanic women: a qualitative study.

PubMed

Mama, Scherezade K; McCurdy, Sheryl A; Evans, Alexandra E; Thompson, Deborah I; Diamond, Pamela M; Lee, Rebecca E

2015-06-01

Ecologic models suggest that multiple levels of influencing factors are important for determining physical activity participation and include individual, social, and environmental factors. The purpose of this qualitative study was to use an ecologic framework to gain a deeper understanding of the underlying behavioral mechanisms that influence physical activity adoption among ethnic minority women. Eighteen African American and Hispanic women completed a 1-hour in-depth interview. Verbatim interview transcripts were analyzed for emergent themes using a constant comparison approach. Women were middle-aged (age M = 43.9 ± 7.3 years), obese (body mass index M = 35.0 ± 8.9 kg/m(2)), and of high socioeconomic status (88.9% completed some college or more, 41.2% reported income >$82,600/year). Participants discussed individual factors, including the need for confidence, motivation and time, and emphasized the importance of environmental factors, including their physical neighborhood environments and safety of and accessibility to physical activity resources. Women talked about caretaking for others and social support and how these influenced physical activity behavior. The findings from this study highlight the multilevel, interactive complexities that influence physical activity, emphasizing the need for a more sophisticated, ecologic approach for increasing physical activity adoption and maintenance among ethnic minority women. Community insight gleaned from this study may be used to better understand determinants of physical activity and develop multilevel solutions and programs guided by an ecologic framework to increase physical activity in ethnic minority women. © 2014 Society for Public Health Education.

Virtual Reality for Artificial Intelligence: human-centered simulation for social science.

PubMed

Cipresso, Pietro; Riva, Giuseppe

2015-01-01

There is a long last tradition in Artificial Intelligence as use of Robots endowing human peculiarities, from a cognitive and emotional point of view, and not only in shape. Today Artificial Intelligence is more oriented to several form of collective intelligence, also building robot simulators (hardware or software) to deeply understand collective behaviors in human beings and society as a whole. Modeling has also been crucial in the social sciences, to understand how complex systems can arise from simple rules. However, while engineers' simulations can be performed in the physical world using robots, for social scientist this is impossible. For decades, researchers tried to improve simulations by endowing artificial agents with simple and complex rules that emulated human behavior also by using artificial intelligence (AI). To include human beings and their real intelligence within artificial societies is now the big challenge. We present an hybrid (human-artificial) platform where experiments can be performed by simulated artificial worlds in the following manner: 1) agents' behaviors are regulated by the behaviors shown in Virtual Reality involving real human beings exposed to specific situations to simulate, and 2) technology transfers these rules into the artificial world. These form a closed-loop of real behaviors inserted into artificial agents, which can be used to study real society.

Rai1 duplication causes physical and behavioral phenotypes in a mouse model of dup(17)(p11.2p11.2)

PubMed Central

Walz, Katherina; Paylor, Richard; Yan, Jiong; Bi, Weimin; Lupski, James R.

2006-01-01

Genomic disorders are conditions that result from DNA rearrangements, such as deletions or duplications. The identification of the dosage-sensitive gene(s) within the rearranged genomic interval is important for the elucidation of genes responsible for complex neurobehavioral phenotypes. Smith-Magenis syndrome is associated with a 3.7-Mb deletion in 17p11.2, and its clinical presentation is caused by retinoic acid inducible 1 (RAI1) haploinsufficiency. The reciprocal microduplication syndrome, dup(17)(p11.2p11.2), manifests several neurobehavioral abnormalities, but the responsible dosage-sensitive gene(s) remain undefined. We previously generated a mouse model for dup(17)(p11.2p11.2), Dp(11)17/+, that recapitulated most of the phenotypes observed in human patients. We have now analyzed compound heterozygous mice carrying a duplication [Dp(11)17] in one chromosome 11 along with a null allele of Rai1 in the other chromosome 11 homologue [Dp(11)17/Rai1– mice] in order to study the relationship between Rai1 gene copy number and the Dp(11)17/+ phenotypes. Normal disomic Rai1 gene dosage was sufficient to rescue the complex physical and behavioral phenotypes observed in Dp(11)17/+ mice, despite altered trisomic copy number of the other 18 genes present in the rearranged genomic interval. These data provide a model for variation in copy number of single genes that could influence common traits such as obesity and behavior. PMID:17024248

A Social Network Approach Reveals Associations between Mouse Social Dominance and Brain Gene Expression.

PubMed

So, Nina; Franks, Becca; Lim, Sean; Curley, James P

2015-01-01

Modelling complex social behavior in the laboratory is challenging and requires analyses of dyadic interactions occurring over time in a physically and socially complex environment. In the current study, we approached the analyses of complex social interactions in group-housed male CD1 mice living in a large vivarium. Intensive observations of social interactions during a 3-week period indicated that male mice form a highly linear and steep dominance hierarchy that is maintained by fighting and chasing behaviors. Individual animals were classified as dominant, sub-dominant or subordinate according to their David's Scores and I& SI ranking. Using a novel dynamic temporal Glicko rating method, we ascertained that the dominance hierarchy was stable across time. Using social network analyses, we characterized the behavior of individuals within 66 unique relationships in the social group. We identified two individual network metrics, Kleinberg's Hub Centrality and Bonacich's Power Centrality, as accurate predictors of individual dominance and power. Comparing across behaviors, we establish that agonistic, grooming and sniffing social networks possess their own distinctive characteristics in terms of density, average path length, reciprocity out-degree centralization and out-closeness centralization. Though grooming ties between individuals were largely independent of other social networks, sniffing relationships were highly predictive of the directionality of agonistic relationships. Individual variation in dominance status was associated with brain gene expression, with more dominant individuals having higher levels of corticotropin releasing factor mRNA in the medial and central nuclei of the amygdala and the medial preoptic area of the hypothalamus, as well as higher levels of hippocampal glucocorticoid receptor and brain-derived neurotrophic factor mRNA. This study demonstrates the potential and significance of combining complex social housing and intensive behavioral characterization of group-living animals with the utilization of novel statistical methods to further our understanding of the neurobiological basis of social behavior at the individual, relationship and group levels.

A Social Network Approach Reveals Associations between Mouse Social Dominance and Brain Gene Expression

PubMed Central

So, Nina; Franks, Becca; Lim, Sean; Curley, James P.

2015-01-01

Modelling complex social behavior in the laboratory is challenging and requires analyses of dyadic interactions occurring over time in a physically and socially complex environment. In the current study, we approached the analyses of complex social interactions in group-housed male CD1 mice living in a large vivarium. Intensive observations of social interactions during a 3-week period indicated that male mice form a highly linear and steep dominance hierarchy that is maintained by fighting and chasing behaviors. Individual animals were classified as dominant, sub-dominant or subordinate according to their David’s Scores and I& SI ranking. Using a novel dynamic temporal Glicko rating method, we ascertained that the dominance hierarchy was stable across time. Using social network analyses, we characterized the behavior of individuals within 66 unique relationships in the social group. We identified two individual network metrics, Kleinberg’s Hub Centrality and Bonacich’s Power Centrality, as accurate predictors of individual dominance and power. Comparing across behaviors, we establish that agonistic, grooming and sniffing social networks possess their own distinctive characteristics in terms of density, average path length, reciprocity out-degree centralization and out-closeness centralization. Though grooming ties between individuals were largely independent of other social networks, sniffing relationships were highly predictive of the directionality of agonistic relationships. Individual variation in dominance status was associated with brain gene expression, with more dominant individuals having higher levels of corticotropin releasing factor mRNA in the medial and central nuclei of the amygdala and the medial preoptic area of the hypothalamus, as well as higher levels of hippocampal glucocorticoid receptor and brain-derived neurotrophic factor mRNA. This study demonstrates the potential and significance of combining complex social housing and intensive behavioral characterization of group-living animals with the utilization of novel statistical methods to further our understanding of the neurobiological basis of social behavior at the individual, relationship and group levels. PMID:26226265

Adaptive and Resilient Soft Tensegrity Robots.

PubMed

Rieffel, John; Mouret, Jean-Baptiste

2018-04-17

Living organisms intertwine soft (e.g., muscle) and hard (e.g., bones) materials, giving them an intrinsic flexibility and resiliency often lacking in conventional rigid robots. The emerging field of soft robotics seeks to harness these same properties to create resilient machines. The nature of soft materials, however, presents considerable challenges to aspects of design, construction, and control-and up until now, the vast majority of gaits for soft robots have been hand-designed through empirical trial-and-error. This article describes an easy-to-assemble tensegrity-based soft robot capable of highly dynamic locomotive gaits and demonstrating structural and behavioral resilience in the face of physical damage. Enabling this is the use of a machine learning algorithm able to discover effective gaits with a minimal number of physical trials. These results lend further credence to soft-robotic approaches that seek to harness the interaction of complex material dynamics to generate a wealth of dynamical behaviors.

Health-Related Quality of Life Among US Workers: Variability Across Occupation Groups.

PubMed

Shockey, Taylor M; Zack, Matthew; Sussell, Aaron

2017-08-01

To examine the health-related quality of life among workers in 22 standard occupation groups using data from the 2013-2014 US Behavioral Risk Factor Surveillance System. We examined the health-related quality of life measures of self-rated health, frequent physical distress, frequent mental distress, frequent activity limitation, and frequent overall unhealthy days by occupation group for 155 839 currently employed adults among 17 states. We performed multiple logistic regression analyses that accounted for the Behavioral Risk Factor Surveillance System's complex survey design to obtain prevalence estimates adjusted for potential confounders. Among all occupation groups, the arts, design, entertainment, sports, and media occupation group reported the highest adjusted prevalence of frequent physical distress, frequent mental distress, frequent activity limitation, and frequent overall unhealthy days. The personal care and service occupation group had the highest adjusted prevalence for fair or poor self-rated health. Workers' jobs affect their health-related quality of life.

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

PubMed Central

2014-01-01

Summary This paper presents computational simulations of single-mode and bimodal atomic force microscopy (AFM) with particular focus on the viscoelastic interactions occurring during tip–sample impact. The surface is modeled by using a standard linear solid model, which is the simplest system that can reproduce creep compliance and stress relaxation, which are fundamental behaviors exhibited by viscoelastic surfaces. The relaxation of the surface in combination with the complexities of bimodal tip–sample impacts gives rise to unique dynamic behaviors that have important consequences with regards to the acquisition of quantitative relationships between the sample properties and the AFM observables. The physics of the tip–sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided. PMID:25383277

Taguchi-generalized regression neural network micro-screening for physical and sensory characteristics of bread.

PubMed

Besseris, George J

2018-03-01

Generalized regression neural networks (GRNN) may act as crowdsourcing cognitive agents to screen small, dense and complex datasets. The concurrent screening and optimization of several complex physical and sensory traits of bread is developed using a structured Taguchi-type micro-mining technique. A novel product outlook is offered to industrial operations to cover separate aspects of smart product design, engineering and marketing. Four controlling factors were selected to be modulated directly on a modern production line: 1) the dough weight, 2) the proofing time, 3) the baking time, and 4) the oven zone temperatures. Concentrated experimental recipes were programmed using the Taguchi-type L 9 (3 4 ) OA-sampler to detect potentially non-linear multi-response tendencies. The fused behavior of the master-ranked bread characteristics behavior was smart sampled with GRNN-crowdsourcing and robust analysis. It was found that the combination of the oven zone temperatures to play a highly influential role in all investigated scenarios. Moreover, the oven zone temperatures and the dough weight appeared to be instrumental when attempting to synchronously adjusting all four physical characteristics. The optimal oven-zone temperature setting for concurrent screening-and-optimization was found to be 270-240 °C. The optimized (median) responses for loaf weight, moisture, height, width, color, flavor, crumb structure, softness, and elasticity are: 782 g, 34.8 %, 9.36 cm, 10.41 cm, 6.6, 7.2, 7.6, 7.3, and 7.0, respectively.

Klopsteg Memorial Lecture (August, 1998): Physics at the breakfast table{emdash}or waking up to physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagel, S.R.

1999-01-01

There are many complex phenomena that are so familiar to us that we forget to ask whether or not they are understood. In this lecture, I will discuss several familiar cases of effects that are so ubiquitous that we hardly realize that they defy our normal intuition about why they happen. The examples of poorly understood classical physics that I will choose can all be viewed at a breakfast table. I will mention the long tendrils left behind by honey spooned from one dish to another, the anomalous flow behavior of granular material, and the annoying rings deposited by spilledmore » coffee on a table after the liquid evaporates. These are all nonlinear hydrodynamic phenomena which not only are of technological importance but can also lead the inquisitive into new realms of physics. {copyright} {ital 1999 American Association of Physics Teachers.}« less

A compact physical model for the simulation of pNML-based architectures

NASA Astrophysics Data System (ADS)

Turvani, G.; Riente, F.; Plozner, E.; Schmitt-Landsiedel, D.; Breitkreutz-v. Gamm, S.

2017-05-01

Among emerging technologies, perpendicular Nanomagnetic Logic (pNML) seems to be very promising because of its capability of combining logic and memory onto the same device, scalability, 3D-integration and low power consumption. Recently, Full Adder (FA) structures clocked by a global magnetic field have been experimentally demonstrated and detailed characterizations of the switching process governing the domain wall (DW) nucleation probability Pnuc and time tnuc have been performed. However, the design of pNML architectures represent a crucial point in the study of this technology; this can have a remarkable impact on the reliability of pNML structures. Here, we present a compact model developed in VHDL which enables to simulate complex pNML architectures while keeping into account critical physical parameters. Therefore, such parameters have been extracted from the experiments, fitted by the corresponding physical equations and encapsulated into the proposed model. Within this, magnetic structures are decomposed into a few basic elements (nucleation centers, nanowires, inverters etc.) represented by the according physical description. To validate the model, we redesigned a FA and compared our simulation results to the experiment. With this compact model of pNML devices we have envisioned a new methodology which makes it possible to simulate and test the physical behavior of complex architectures with very low computational costs.

Renormalization Group Tutorial

NASA Technical Reports Server (NTRS)

Bell, Thomas L.

2004-01-01

Complex physical systems sometimes have statistical behavior characterized by power- law dependence on the parameters of the system and spatial variability with no particular characteristic scale as the parameters approach critical values. The renormalization group (RG) approach was developed in the fields of statistical mechanics and quantum field theory to derive quantitative predictions of such behavior in cases where conventional methods of analysis fail. Techniques based on these ideas have since been extended to treat problems in many different fields, and in particular, the behavior of turbulent fluids. This lecture will describe a relatively simple but nontrivial example of the RG approach applied to the diffusion of photons out of a stellar medium when the photons have wavelengths near that of an emission line of atoms in the medium.

Innovative techniques to analyze time series of geomagnetic activity indices

NASA Astrophysics Data System (ADS)

Balasis, Georgios; Papadimitriou, Constantinos; Daglis, Ioannis A.; Potirakis, Stelios M.; Eftaxias, Konstantinos

2016-04-01

Magnetic storms are undoubtedly among the most important phenomena in space physics and also a central subject of space weather. The non-extensive Tsallis entropy has been recently introduced, as an effective complexity measure for the analysis of the geomagnetic activity Dst index. The Tsallis entropy sensitively shows the complexity dissimilarity among different "physiological" (normal) and "pathological" states (intense magnetic storms). More precisely, the Tsallis entropy implies the emergence of two distinct patterns: (i) a pattern associated with the intense magnetic storms, which is characterized by a higher degree of organization, and (ii) a pattern associated with normal periods, which is characterized by a lower degree of organization. Other entropy measures such as Block Entropy, T-Complexity, Approximate Entropy, Sample Entropy and Fuzzy Entropy verify the above mentioned result. Importantly, the wavelet spectral analysis in terms of Hurst exponent, H, also shows the existence of two different patterns: (i) a pattern associated with the intense magnetic storms, which is characterized by a fractional Brownian persistent behavior (ii) a pattern associated with normal periods, which is characterized by a fractional Brownian anti-persistent behavior. Finally, we observe universality in the magnetic storm and earthquake dynamics, on a basis of a modified form of the Gutenberg-Richter law for the Tsallis statistics. This finding suggests a common approach to the interpretation of both phenomena in terms of the same driving physical mechanism. Signatures of discrete scale invariance in Dst time series further supports the aforementioned proposal.

Hunting Solomonoff's Swans: Exploring the Boundary Between Physics and Statistics in Hydrological Modeling

NASA Astrophysics Data System (ADS)

Nearing, G. S.

2014-12-01

Statistical models consistently out-perform conceptual models in the short term, however to account for a nonstationary future (or an unobserved past) scientists prefer to base predictions on unchanging and commutable properties of the universe - i.e., physics. The problem with physically-based hydrology models is, of course, that they aren't really based on physics - they are based on statistical approximations of physical interactions, and we almost uniformly lack an understanding of the entropy associated with these approximations. Thermodynamics is successful precisely because entropy statistics are computable for homogeneous (well-mixed) systems, and ergodic arguments explain the success of Newton's laws to describe systems that are fundamentally quantum in nature. Unfortunately, similar arguments do not hold for systems like watersheds that are heterogeneous at a wide range of scales. Ray Solomonoff formalized the situation in 1968 by showing that given infinite evidence, simultaneously minimizing model complexity and entropy in predictions always leads to the best possible model. The open question in hydrology is about what happens when we don't have infinite evidence - for example, when the future will not look like the past, or when one watershed does not behave like another. How do we isolate stationary and commutable components of watershed behavior? I propose that one possible answer to this dilemma lies in a formal combination of physics and statistics. In this talk I outline my recent analogue (Solomonoff's theorem was digital) of Solomonoff's idea that allows us to quantify the complexity/entropy tradeoff in a way that is intuitive to physical scientists. I show how to formally combine "physical" and statistical methods for model development in a way that allows us to derive the theoretically best possible model given any given physics approximation(s) and available observations. Finally, I apply an analogue of Solomonoff's theorem to evaluate the tradeoff between model complexity and prediction power.

Representations of Complexity: How Nature Appears in Our Theories

PubMed Central

2013-01-01

In science we study processes in the material world. The way these processes operate can be discovered by conducting experiments that activate them, and findings from such experiments can lead to functional complexity theories of how the material processes work. The results of a good functional theory will agree with experimental measurements, but the theory may not incorporate in its algorithmic workings a representation of the material processes themselves. Nevertheless, the algorithmic operation of a good functional theory may be said to make contact with material reality by incorporating the emergent computations the material processes carry out. These points are illustrated in the experimental analysis of behavior by considering an evolutionary theory of behavior dynamics, the algorithmic operation of which does not correspond to material features of the physical world, but the functional output of which agrees quantitatively and qualitatively with findings from a large body of research with live organisms. PMID:28018044

Training Knowledge Bots for Physics-Based Simulations Using Artificial Neural Networks

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.; Wong, Jay Ming

2014-01-01

Millions of complex physics-based simulations are required for design of an aerospace vehicle. These simulations are usually performed by highly trained and skilled analysts, who execute, monitor, and steer each simulation. Analysts rely heavily on their broad experience that may have taken 20-30 years to accumulate. In addition, the simulation software is complex in nature, requiring significant computational resources. Simulations of system of systems become even more complex and are beyond human capacity to effectively learn their behavior. IBM has developed machines that can learn and compete successfully with a chess grandmaster and most successful jeopardy contestants. These machines are capable of learning some complex problems much faster than humans can learn. In this paper, we propose using artificial neural network to train knowledge bots to identify the idiosyncrasies of simulation software and recognize patterns that can lead to successful simulations. We examine the use of knowledge bots for applications of computational fluid dynamics (CFD), trajectory analysis, commercial finite-element analysis software, and slosh propellant dynamics. We will show that machine learning algorithms can be used to learn the idiosyncrasies of computational simulations and identify regions of instability without including any additional information about their mathematical form or applied discretization approaches.

Thermo-mechanical behavior of power electronic packaging assemblies: From characterization to predictive simulation of lifetimes

NASA Astrophysics Data System (ADS)

Dalverny, O.; Alexis, J.

2018-02-01

This article deals with thermo-mechanical behavior of power electronic modules used in several transportation applications as railway, aeronautic or automotive systems. Due to a multi-layered structures, involving different materials with a large variation of coefficient of thermal expansion, temperature variations originated from active or passive cycling (respectively from die dissipation or environmental constraint) induces strain and stresses field variations, giving fatigue phenomenon of the system. The analysis of the behavior of these systems and their dimensioning require the implementation of complex modeling strategies by both the multi-physical and the multi-scale character of the power modules. In this paper we present some solutions for studying the thermomechanical behavior of brazed assemblies as well as taking into account the interfaces represented by the numerous metallizations involved in the process assembly.

Self-Regulatory Fatigue, Quality of Life, Health Behaviors, and Coping in Patients with Hematologic Malignancies

PubMed Central

Ehlers, Shawna L.; Patten, Christi A.; Gastineau, Dennis A.

2015-01-01

Background Self-regulatory fatigue may play an important role in a complex medical illness. Purpose Examine associations between self-regulatory fatigue, quality of life, and health behaviors in patients pre- (N=213) and 1-year post-hematopoietic stem cell transplantation (HSCT; N=140). Associations between self-regulatory fatigue and coping strategies pre-HSCT were also examined. Method Pre- and 1-year post-HSCT data collection. Hierarchical linear regression modeling. Results Higher self-regulatory fatigue pre-HSCT associated with lower overall, physical, social, emotional, and functional quality of life pre- (p’s<.001) and 1-year post-HSCT (p’s<.01); lower physical activity pre-HSCT (p<.02) and post-HSCT (p<.03) and less healthy nutritional intake post-HSCT (p<.01); changes (i.e., decrease) in quality of life and healthy nutrition over the follow-up year; and use of avoidance coping strategies pre-HSCT (p’s<.001). Conclusion This is the first study to show self-regulatory fatigue pre-HSCT relating to decreased quality of life and health behaviors, and predicting changes in these variables 1-year post-HSCT. PMID:24802991

Rumor diffusion model with spatio-temporal diffusion and uncertainty of behavior decision in complex social networks

NASA Astrophysics Data System (ADS)

Zhu, Liang; Wang, Youguo

2018-07-01

In this paper, a rumor diffusion model with uncertainty of human behavior under spatio-temporal diffusion framework is established. Take physical significance of spatial diffusion into account, a diffusion threshold is set under which the rumor is not a trend topic and only spreads along determined physical connections. Heterogeneity of degree distribution and distance distribution has also been considered in theoretical model at the same time. The global existence and uniqueness of classical solution are proved with a Lyapunov function and an approximate classical solution in form of infinite series is constructed with a system of eigenfunction. Simulations and numerical solutions both on Watts-Strogatz (WS) network and Barabási-Albert (BA) network display the variation of density of infected connections from spatial and temporal dimensions. Relevant results show that the density of infected connections is dominated by network topology and uncertainty of human behavior at threshold time. With increase of social capability, rumor diffuses to the steady state in a higher speed. And the variation trends of diffusion size with uncertainty are diverse on different artificial networks.

The SAM framework: modeling the effects of management factors on human behavior in risk analysis.

PubMed

Murphy, D M; Paté-Cornell, M E

1996-08-01

Complex engineered systems, such as nuclear reactors and chemical plants, have the potential for catastrophic failure with disastrous consequences. In recent years, human and management factors have been recognized as frequent root causes of major failures in such systems. However, classical probabilistic risk analysis (PRA) techniques do not account for the underlying causes of these errors because they focus on the physical system and do not explicitly address the link between components' performance and organizational factors. This paper describes a general approach for addressing the human and management causes of system failure, called the SAM (System-Action-Management) framework. Beginning with a quantitative risk model of the physical system, SAM expands the scope of analysis to incorporate first the decisions and actions of individuals that affect the physical system. SAM then links management factors (incentives, training, policies and procedures, selection criteria, etc.) to those decisions and actions. The focus of this paper is on four quantitative models of action that describe this last relationship. These models address the formation of intentions for action and their execution as a function of the organizational environment. Intention formation is described by three alternative models: a rational model, a bounded rationality model, and a rule-based model. The execution of intentions is then modeled separately. These four models are designed to assess the probabilities of individual actions from the perspective of management, thus reflecting the uncertainties inherent to human behavior. The SAM framework is illustrated for a hypothetical case of hazardous materials transportation. This framework can be used as a tool to increase the safety and reliability of complex technical systems by modifying the organization, rather than, or in addition to, re-designing the physical system.

A theoretical and experimental technique to measure fracture properties in viscoelastic solids

NASA Astrophysics Data System (ADS)

Freitas, Felipe Araujo Colares De

Prediction of crack growth in engineering structures is necessary for better analysis and design. However, this prediction becomes quite complex for certain materials in which the fracture behavior is both rate and path dependent. Asphaltic materials used in pavements have that intrinsic complexity in their behavior. A lot of research effort has been devoted to better understanding viscoelastic behavior and fracture in such materials. This dissertation presents a further refinement of an experimental test setup, which is significantly different from standard testing protocols, to measure viscoelastic and fracture properties of nonlinear viscoelastic solids, such as asphaltic materials. The results presented herein are primarily for experiments with asphalt, but the test procedure can be used for other viscoelastic materials as well. Even though the test is designed as a fracture test, experiments on the investigated materials have uncovered very complex phenomena prior to fracture. Viscoelasticity and micromechanics are used to explain some of the physical phenomena observed in the tests. The material behavior prior to fracture includes both viscoelastic behavior and a necking effect, which is further discussed in the appendix of the present study. The dissertation outlines a theoretical model for the prediction of tractions ahead of the crack tip. The major contribution herein lies in the development of the experimental procedure for evaluating the material parameters necessary for deploying the model in the prediction of ductile crack growth. Finally, predictions of crack growth in a double cantilever beam specimens and asphalt concrete samples are presented in order to demonstrate the power of this approach for predicting crack growth in viscoelastic media.

Perspective: Sloppiness and emergent theories in physics, biology, and beyond.

PubMed

Transtrum, Mark K; Machta, Benjamin B; Brown, Kevin S; Daniels, Bryan C; Myers, Christopher R; Sethna, James P

2015-07-07

Large scale models of physical phenomena demand the development of new statistical and computational tools in order to be effective. Many such models are "sloppy," i.e., exhibit behavior controlled by a relatively small number of parameter combinations. We review an information theoretic framework for analyzing sloppy models. This formalism is based on the Fisher information matrix, which is interpreted as a Riemannian metric on a parameterized space of models. Distance in this space is a measure of how distinguishable two models are based on their predictions. Sloppy model manifolds are bounded with a hierarchy of widths and extrinsic curvatures. The manifold boundary approximation can extract the simple, hidden theory from complicated sloppy models. We attribute the success of simple effective models in physics as likewise emerging from complicated processes exhibiting a low effective dimensionality. We discuss the ramifications and consequences of sloppy models for biochemistry and science more generally. We suggest that the reason our complex world is understandable is due to the same fundamental reason: simple theories of macroscopic behavior are hidden inside complicated microscopic processes.

A model of motor performance during surface penetration: from physics to voluntary control.

PubMed

Klatzky, Roberta L; Gershon, Pnina; Shivaprabhu, Vikas; Lee, Randy; Wu, Bing; Stetten, George; Swendsen, Robert H

2013-10-01

The act of puncturing a surface with a hand-held tool is a ubiquitous but complex motor behavior that requires precise force control to avoid potentially severe consequences. We present a detailed model of puncture over a time course of approximately 1,000 ms, which is fit to kinematic data from individual punctures, obtained via a simulation with high-fidelity force feedback. The model describes puncture as proceeding from purely physically determined interactions between the surface and tool, through decline of force due to biomechanical viscosity, to cortically mediated voluntary control. When fit to the data, it yields parameters for the inertial mass of the tool/person coupling, time characteristic of force decline, onset of active braking, stopping time and distance, and late oscillatory behavior, all of which the analysis relates to physical variables manipulated in the simulation. While the present data characterize distinct phases of motor performance in a group of healthy young adults, the approach could potentially be extended to quantify the performance of individuals from other populations, e.g., with sensory-motor impairments. Applications to surgical force control devices are also considered.

Linking Local Scale Ecosystem Science to Regional Scale Management

NASA Astrophysics Data System (ADS)

Shope, C. L.; Tenhunen, J.; Peiffer, S.

2012-04-01

Ecosystem management with respect to sufficient water yield, a quality water supply, habitat and biodiversity conservation, and climate change effects requires substantial observational data at a range of scales. Complex interactions of local physical processes oftentimes vary over space and time, particularly in locations with extreme meteorological conditions. Modifications to local conditions (ie: agricultural land use changes, nutrient additions, landscape management, water usage) can further affect regional ecosystem services. The international, inter-disciplinary TERRECO research group is intensively investigating a variety of local processes, parameters, and conditions to link complex physical, economic, and social interactions at the regional scale. Field-based meteorology, hydrology, soil physics, plant production, solute and sediment transport, economic, and social behavior data were measured in a South Korean catchment. The data are used to parameterize suite of models describing local to landscape level water, sediment, nutrient, and monetary relationships. We focus on using the agricultural and hydrological SWAT model to synthesize the experimental field data and local-scale models throughout the catchment. The approach of our study was to describe local scientific processes, link potential interrelationships between different processes, and predict environmentally efficient management efforts. The Haean catchment case study shows how research can be structured to provide cross-disciplinary scientific linkages describing complex ecosystems and landscapes that can be used for regional management evaluations and predictions.

Fishermen Follow Fine-scaled Physical Ocean Features For Finance

NASA Astrophysics Data System (ADS)

Fuller, E.; Watson, J. R.; Samhouri, J.; Castruccio, F. S.

2016-12-01

The seascapes on which many millions of people make their living and secure food have complex and dynamic spatial features - the figurative hills and valleys - that control where and how people work at sea. Here, we quantify the physical mosaic of the surface ocean by identifying Lagrangian Coherent Structures for a whole seascape - the California Current - and assess their impact on the spatial distribution of fishing. We show that there is a mixed response: some fisheries track these physical features, and others avoid them. This spatial behavior maps to economic impacts: we find that tuna fishermen can expect to make three times more revenue per trip if fishing occurs on strong coherent structures. These results highlight a connection between the physical state of the oceans, the spatial patterns of human activity and ultimately the economic prosperity of coastal communities.

Surficial geological tools in fluvial geomorphology: Chapter 2

USGS Publications Warehouse

Jacobson, Robert B.; O'Connor, James E.; Oguchi, Takashi

2016-01-01

Increasingly, environmental scientists are being asked to develop an understanding of how rivers and streams have been altered by environmental stresses, whether rivers are subject to physical or chemical hazards, how they can be restored, and how they will respond to future environmental change. These questions present substantive challenges to the discipline of fluvial geomorphology, especially since decades of geomorphologic research have demonstrated the general complexity of fluvial systems. It follows from the concept of complex response that synoptic and short-term historical views of rivers will often give misleading understanding of future behavior. Nevertheless, broadly trained geomorphologists can address questions involving complex natural systems by drawing from a tool box that commonly includes the principles and methods of geology, hydrology, hydraulics, engineering, and ecology.

Robust fault diagnosis of physical systems in operation. Ph.D. Thesis - Rutgers - The State Univ.

NASA Technical Reports Server (NTRS)

Abbott, Kathy Hamilton

1991-01-01

Ideas are presented and demonstrated for improved robustness in diagnostic problem solving of complex physical systems in operation, or operative diagnosis. The first idea is that graceful degradation can be viewed as reasoning at higher levels of abstraction whenever the more detailed levels proved to be incomplete or inadequate. A form of abstraction is defined that applies this view to the problem of diagnosis. In this form of abstraction, named status abstraction, two levels are defined. The lower level of abstraction corresponds to the level of detail at which most current knowledge-based diagnosis systems reason. At the higher level, a graph representation is presented that describes the real-world physical system. An incremental, constructive approach to manipulating this graph representation is demonstrated that supports certain characteristics of operative diagnosis. The suitability of this constructive approach is shown for diagnosing fault propagation behavior over time, and for sometimes diagnosing systems with feedback. A way is shown to represent different semantics in the same type of graph representation to characterize different types of fault propagation behavior. An approach is demonstrated that threats these different behaviors as different fault classes, and the approach moves to other classes when previous classes fail to generate suitable hypotheses. These ideas are implemented in a computer program named Draphys (Diagnostic Reasoning About Physical Systems) and demonstrated for the domain of inflight aircraft subsystems, specifically a propulsion system (containing two turbofan systems and a fuel system) and hydraulic subsystem.

An underwater robo-leader for collective motion studies

NASA Astrophysics Data System (ADS)

Sanchez, Yair; Wilhelmus, Monica M.

2016-11-01

A wide range of aquatic species, from bacteria to large tuna, exhibits collective behavior. It has long been hypothesized that the formation of complex configurations brings an energetic advantage to the members of a group as well as protection against larger predators or harmful agents. Lately, however, laboratory experiments have suggested that both the physics and the behavioral aspects of collective motion yield more complexity than previously attributed. With the goal to understand the fluid mechanical implications behind collective motion in a laboratory setting, we have developed a new device to induce this behavior on demand. Following recent studies of lab-induced vertical migration of Artemia salina, we have designed and constructed a remotely controlled underwater robotic swimmer that acts as a leader for groups of phototactic organisms. Preliminary quantitative flow visualizations done during vertical migration of brine shrimp show that this new instrument does induce collective motion in the laboratory. With this setup, we can address the hydrodynamic effect of having different swarm configurations, a variable that so far has been challenging to study in a controllable and reproducible manner.

Supramolecular structure, phase behavior and thermo-rheological properties of a poly (L-lactide-co-ε-caprolactone) statistical copolymer.

PubMed

Ugartemendia, Jone M; Muñoz, M E; Santamaria, A; Sarasua, J R

2015-08-01

PLAcoCL samples, both unaged, termed PLAcoCLu, and aged over time, PLAcoCLa, were prepared and analyzed to study the phase structure, morphology, and their evolution under non-quiescent conditions. X- ray diffraction, Differential Scanning Calorimetry and Atomic Force Microscopy were complemented with thermo-rheological measurements to reveal that PLAcoCL evolves over time from a single amorphous metastable state to a 3 phase system, made up of two compositionally different amorphous phases and a crystalline phase. The supramolecular arrangements developed during aging lead to a rheological complex behavior in the PLAcoCLa copolymer: Around Tt=131 °C thermo-rheological complexity and a peculiar chain mobility reduction were observed, but at T>Tt the thermo-rheological response of a homogeneous system was recorded. In comparison with the latter, the PLLA/PCL 70:30 physical blend counterpart showed double amorphous phase behavior at all temperatures, supporting the hypothesis that phase separation in the PLAcoCLa copolymer is caused by the crystallization of polylactide segment blocks during aging. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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.

Artificial intelligence exploration of unstable protocells leads to predictable properties and discovery of collective behavior.

PubMed

Points, Laurie J; Taylor, James Ward; Grizou, Jonathan; Donkers, Kevin; Cronin, Leroy

2018-01-30

Protocell models are used to investigate how cells might have first assembled on Earth. Some, like oil-in-water droplets, can be seemingly simple models, while able to exhibit complex and unpredictable behaviors. How such simple oil-in-water systems can come together to yield complex and life-like behaviors remains a key question. Herein, we illustrate how the combination of automated experimentation and image processing, physicochemical analysis, and machine learning allows significant advances to be made in understanding the driving forces behind oil-in-water droplet behaviors. Utilizing >7,000 experiments collected using an autonomous robotic platform, we illustrate how smart automation cannot only help with exploration, optimization, and discovery of new behaviors, but can also be core to developing fundamental understanding of such systems. Using this process, we were able to relate droplet formulation to behavior via predicted physical properties, and to identify and predict more occurrences of a rare collective droplet behavior, droplet swarming. Proton NMR spectroscopic and qualitative pH methods enabled us to better understand oil dissolution, chemical change, phase transitions, and droplet and aqueous phase flows, illustrating the utility of the combination of smart-automation and traditional analytical chemistry techniques. We further extended our study for the simultaneous exploration of both the oil and aqueous phases using a robotic platform. Overall, this work shows that the combination of chemistry, robotics, and artificial intelligence enables discovery, prediction, and mechanistic understanding in ways that no one approach could achieve alone.

Investigations into the mechanical and physical behavior of thermoplastic elastomers

NASA Astrophysics Data System (ADS)

Wright, Kathryn Janelle

This thesis describes investigations into the physical and mechanical characteristics of two commercial thermoplastic elastomer (TPE) systems. Both systems studied exhibit elastomeric behavior similar to more traditional crosslinked elastomers; however, in these TPEs non-conventional polymer architectures and morphologies are used to produce their elastomeric behavior. The two TPEs of interest are ethylene-propylene random copolymers and dynamically vulcanized blends of ethylene-propylene-diene monomer (EPDM) and isotactic polypropylene (iPP). Very few studies have examined the mechanical behavior of these materials in terms of their composition and morphology. As such, the primary goal of this research is to both qualitatively and quantitatively understand the influence of composition and morphology on mechanical behavior. In additional very little information is available that compares their performance with that of crosslinked elastomers. As a result, the secondary goal is to qualitatively compare the mechanical responses of these TPEs with that of their more traditional counterparts. The ethylene-propylene copolymers studied have very high comonomer contents and exhibit slow crystallization kinetics. Their morphology consists of nanoscale crystallites embedded in an amorphous rubbery matrix. These crystallites act as physical crosslinks that allow for elasticity. Slow crystallization causes subsequent changes in mechanical behavior that take place over days and even weeks. Physical responses (e.g., density, crystallization kinetics, and crystal structure) of five copolymer compositions are investigated. Mechanical responses (e.g., stiffness, ductility, yielding, and reversibility) are also examined. Finally, the influence of morphology on deformation is studied using in situ analytical techniques. The EPDM/iPP blends are dynamically vulcanized which produces a complex morphology consisting of chemically crosslinked EPDM domains embedded within a semicrystalline iPP matrix. Six compositions are investigated as a function of three parameters: major volume fraction, iPP molecular weight, and EPDM cure state. The influence of these parameters on morphology and resulting mechanical behavior is examined. This work culminates in the development of a morphological model to describe the steady-state reversibility of these EPDM/iPP blends. The model is then evaluated in terms of composition and cure state.

The Emergence of Temporal Structures in Dynamical Systems

NASA Astrophysics Data System (ADS)

Mainzer, Klaus

2010-10-01

Dynamical systems in classical, relativistic and quantum physics are ruled by laws with time reversibility. Complex dynamical systems with time-irreversibility are known from thermodynamics, biological evolution, growth of organisms, brain research, aging of people, and historical processes in social sciences. Complex systems are systems that compromise many interacting parts with the ability to generate a new quality of macroscopic collective behavior the manifestations of which are the spontaneous emergence of distinctive temporal, spatial or functional structures. But, emergence is no mystery. In a general meaning, the emergence of macroscopic features results from the nonlinear interactions of the elements in a complex system. Mathematically, the emergence of irreversible structures is modelled by phase transitions in non-equilibrium dynamics of complex systems. These methods have been modified even for chemical, biological, economic and societal applications (e.g., econophysics). Emergence of irreversible structures can also be simulated by computational systems. The question arises how the emergence of irreversible structures is compatible with the reversibility of fundamental physical laws. It is argued that, according to quantum cosmology, cosmic evolution leads from symmetry to complexity of irreversible structures by symmetry breaking and phase transitions. Thus, arrows of time and aging processes are not only subjective experiences or even contradictions to natural laws, but they can be explained by quantum cosmology and the nonlinear dynamics of complex systems. Human experiences and religious concepts of arrows of time are considered in a modern scientific framework. Platonic ideas of eternity are at least understandable with respect to mathematical invariance and symmetry of physical laws. Heraclit’s world of change and dynamics can be mapped onto our daily real-life experiences of arrows of time.

Retrieving hydrological connectivity from empirical causality in karst systems

NASA Astrophysics Data System (ADS)

Delforge, Damien; Vanclooster, Marnik; Van Camp, Michel; Poulain, Amaël; Watlet, Arnaud; Hallet, Vincent; Kaufmann, Olivier; Francis, Olivier

2017-04-01

Because of their complexity, karst systems exhibit nonlinear dynamics. Moreover, if one attempts to model a karst, the hidden behavior complicates the choice of the most suitable model. Therefore, both intense investigation methods and nonlinear data analysis are needed to reveal the underlying hydrological connectivity as a prior for a consistent physically based modelling approach. Convergent Cross Mapping (CCM), a recent method, promises to identify causal relationships between time series belonging to the same dynamical systems. The method is based on phase space reconstruction and is suitable for nonlinear dynamics. As an empirical causation detection method, it could be used to highlight the hidden complexity of a karst system by revealing its inner hydrological and dynamical connectivity. Hence, if one can link causal relationships to physical processes, the method should show great potential to support physically based model structure selection. We present the results of numerical experiments using karst model blocks combined in different structures to generate time series from actual rainfall series. CCM is applied between the time series to investigate if the empirical causation detection is consistent with the hydrological connectivity suggested by the karst model.

Physical activity interventions and children's mental function: An introduction and overview

PubMed Central

Tomporowski, Phillip D.; Lambourne, Kate; Okumura, Michelle S.

2011-01-01

Background This review provides a historical overview of physical activity interventions designed by American educators and an evaluation of research that has assessed the effects of exercise on children's mental function. Method Historical descriptions of the emergence of American physical education doctrine throughout the 20th century were evaluated. Prior reviews of studies that assessed the effects of single acute bouts of exercise and the effects of chronic exercise training on children's mental function were examined and the results of recent studies were summarized. Results Physical activity interventions designed for American children have reflected two competing views: activities should promote physical fitness and activities should promote social, emotional, and intellectual development. Research results indicate that exercise fosters the emergence of children's mental function; particularly executive functioning. The route by which physical activity impacts mental functioning is complex and is likely moderated by several variables, including physical fitness level, health status, and numerous psycho-social factors. Conclusion Physical activity interventions for children should be designed to meet multiple objectives; e.g., optimize physical fitness, promote health-related behaviors that offset obesity, and facilitate mental development. PMID:21420981

Tell Me How to Do This Thing Called Design! Practical Application of Complexity Theory to Military Operations

DTIC Science & Technology

2011-04-08

into how economics, information theory and computer science, psychology, sociology, evolutionary biology, physics (quantum mechanics) and cosmology ...include knowledge and definition of “self” (as “self” is part of the environment) and the shared experience and perspective of others  That...including information, entropy, quantum behavior, and cosmological progress In short I assume the above and therefore my recommendations could be

Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

PubMed

Arneodo, Ezequiel M; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B

2012-01-01

Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform.

Postural complexity influences development in infants born preterm with brain injury: relating perception-action theory to 3 cases.

PubMed

Dusing, Stacey C; Izzo, Theresa; Thacker, Leroy R; Galloway, James Cole

2014-10-01

Perception-action theory suggests a cyclical relationship between movement and perceptual information. In this case series, changes in postural complexity were used to quantify an infant's action and perception during the development of early motor behaviors. Three infants born preterm with periventricular white matter injury were included. Longitudinal changes in postural complexity (approximate entropy of the center of pressure), head control, reaching, and global development, measured with the Test of Infant Motor Performance and the Bayley Scales of Infant and Toddler Development, were assessed every 0.5 to 3 months during the first year of life. All 3 infants demonstrated altered postural complexity and developmental delays. However, the timing of the altered postural complexity and the type of delays varied among the infants. For infant 1, reduced postural complexity or limited action while learning to control her head in the midline position may have contributed to her motor delay. However, her ability to adapt her postural complexity eventually may have supported her ability to learn from her environment, as reflected in her relative cognitive strength. For infant 2, limited early postural complexity may have negatively affected his learning through action, resulting in cognitive delay. For infant 3, an increase in postural complexity above typical levels was associated with declining neurological status. Postural complexity is proposed as a measure of perception and action in the postural control system during the development of early behaviors. An optimal, intermediate level of postural complexity supports the use of a variety of postural control strategies and enhances the perception-action cycle. Either excessive or reduced postural complexity may contribute to developmental delays in infants born preterm with white matter injury. © 2014 American Physical Therapy Association.

Tools for Detecting Causality in Space Systems

NASA Astrophysics Data System (ADS)

Johnson, J.; Wing, S.

2017-12-01

Complex systems such as the solar and magnetospheric envivonment often exhibit patterns of behavior that suggest underlying organizing principles. Causality is a key organizing principle that is particularly difficult to establish in strongly coupled nonlinear systems, but essential for understanding and modeling the behavior of systems. While traditional methods of time-series analysis can identify linear correlations, they do not adequately quantify the distinction between causal and coincidental dependence. We discuss tools for detecting causality including: granger causality, transfer entropy, conditional redundancy, and convergent cross maps. The tools are illustrated by applications to magnetospheric and solar physics including radiation belt, Dst (a magnetospheric state variable), substorm, and solar cycle dynamics.

Exsolution as an Example of Complex-System Behavior

NASA Astrophysics Data System (ADS)

Mogk, D. W.; Dutrow, B. L.

2010-12-01

Exsolution in minerals is an important process that occurs in a wide range of mineral groups (e.g. alkali feldspars, pyroxenes, amphiboles, carbonates, oxides, sulfides) in response to changing physical conditions. Exsolution describes a physical process in which a mineral with an initially homogeneous solid solution separates into at least two distinct derivative minerals of disparate composition and is typically interpreted as the product of unmixing in response to lattice strain during slow cooling. Such a process is typically taught in introductory mineralogy and petrology courses, in part because exsolution textures can be readily observed in hand sample or thin section. Exsolution is typically represented on equilibrium binary phase diagrams (T-X), and compositions of the unmixed products can be used in geothermobarometry to calculate temperatures and pressures of initial equilibration or compositions of the unmixed products. Although central to course content, traditional approaches to teaching exsolution are largely descriptive, and do not address the underlying principles that drive this phenomenon: that is, dissipation of energy results in segregating and self-organizing behavior of the system. This process exemplifies complex-system behavior. We use perthite formation (i.e. exsolution in the alkali feldspar system) in a series of scaffolded exercises to teach and more completely demonstrate complex-system behavior. These exercises include the use of: 1) hand samples and a series of optical and TEM photomicrographs to display the scale invariance of perthite textures; 2) a puzzle activity in which a chessboard is used as an analog model of atomic positions and nickels and pennies are used to represent individual atoms (Na and K respectively); sequential moves to optimize contacts with similar coins approximates minimization of lattice energies and reveals a power-law relationship as the system becomes increasingly segregated as a function of time to create exsolution textures; 3) the NetLogo computer modeling program to demonstrate segregating behavior; 4) visualizations based on the binary alkali feldspar phase diagram to demonstrate changes to the state of the system over a range of temperatures, and 5) a series of follow-on thought questions. An interesting apparent paradox that our students should consider concerns the flow of mass and energy in natural systems. Commonly, we simply note that mass and energy typically flow down natural gradients (thermal, chemical potential) to attain a homogeneous equilibrium state; however, exsolution produces a segregated state of the system in the lowest energy configuration. Why? Complex-system behavior can be discovered in a wide range of geological phenomena such as exsolution, and could be explicitly identified throughout the geoscience curriculum as a mechanism to teach about interacting systems.

Student designed experiments to learn fluids

NASA Astrophysics Data System (ADS)

Stern, Catalina

2013-11-01

Lasers and high speed cameras are a wonderful tool to visualize the very complex behavior of fluids, and to help students grasp concepts like turbulence, surface tension and vorticity. In this work we present experiments done by physics students in their senior year at the School of Science of the National University of Mexico as a final project in the continuum mechanics course. Every semester, the students make an oral presentation of their work and videos and images are kept in the web page ``Pasión por los Fluidos''. I acknowledge support from the Physics Department of Facultad de Ciencias, Universidad Nacional Autónoma de México.

Mechanical design of DNA nanostructures.

PubMed

Castro, Carlos E; Su, Hai-Jun; Marras, Alexander E; Zhou, Lifeng; Johnson, Joshua

2015-04-14

Structural DNA nanotechnology is a rapidly emerging field that has demonstrated great potential for applications such as single molecule sensing, drug delivery, and templating molecular components. As the applications of DNA nanotechnology expand, a consideration of their mechanical behavior is becoming essential to understand how these structures will respond to physical interactions. This review considers three major avenues of recent progress in this area: (1) measuring and designing mechanical properties of DNA nanostructures, (2) designing complex nanostructures based on imposed mechanical stresses, and (3) designing and controlling structurally dynamic nanostructures. This work has laid the foundation for mechanically active nanomachines that can generate, transmit, and respond to physical cues in molecular systems.

Personal health behaviors and role-modeling attitudes of physical therapists and physical therapist students: a cross-sectional study.

PubMed

Black, Beth; Marcoux, Beth C; Stiller, Christine; Qu, Xianggui; Gellish, Ronald

2012-11-01

Physical therapists have been encouraged to engage in health promotion practice. Health professionals who engage in healthy behaviors themselves are more apt to recommend those behaviors, and patients are more motivated to change their behaviors when their health care provider is a credible role model. The purpose of this study was to describe the health behaviors and role-modeling attitudes of physical therapists and physical therapist students. This study was a descriptive cross-sectional survey. A national sample of 405 physical therapists and 329 physical therapist students participated in the survey. Participants' attitudes toward role modeling and behaviors related to physical activity, fruit and vegetable consumption, abstention from smoking, and maintenance of a healthy weight were measured. Wilcoxon rank sum tests were used to examine differences in attitudes and behaviors between physical therapists and physical therapist students. A majority of the participants reported that they engage in regular physical activity (80.8%), eat fruits and vegetables (60.3%), do not smoke (99.4%), and maintain a healthy weight (78.7%). Although there were no differences in behaviors, physical therapist students were more likely to believe that role modeling is a powerful teaching tool, physical therapist professionals should "practice what they preach," physical activity is a desirable behavior, and physical therapist professionals should be role models for nonsmoking and maintaining a healthy weight. Limitations of this study include the potential for response bias and social desirability bias. Physical therapists and physical therapist students engage in health-promoting behaviors at similarly high rates but differ in role-modeling attitudes.

What Can We Learn from a Simple Physics-Based Earthquake Simulator?

NASA Astrophysics Data System (ADS)

Artale Harris, Pietro; Marzocchi, Warner; Melini, Daniele

2018-03-01

Physics-based earthquake simulators are becoming a popular tool to investigate on the earthquake occurrence process. So far, the development of earthquake simulators is commonly led by the approach "the more physics, the better". However, this approach may hamper the comprehension of the outcomes of the simulator; in fact, within complex models, it may be difficult to understand which physical parameters are the most relevant to the features of the seismic catalog at which we are interested. For this reason, here, we take an opposite approach and analyze the behavior of a purposely simple earthquake simulator applied to a set of California faults. The idea is that a simple simulator may be more informative than a complex one for some specific scientific objectives, because it is more understandable. Our earthquake simulator has three main components: the first one is a realistic tectonic setting, i.e., a fault data set of California; the second is the application of quantitative laws for earthquake generation on each single fault, and the last is the fault interaction modeling through the Coulomb Failure Function. The analysis of this simple simulator shows that: (1) the short-term clustering can be reproduced by a set of faults with an almost periodic behavior, which interact according to a Coulomb failure function model; (2) a long-term behavior showing supercycles of the seismic activity exists only in a markedly deterministic framework, and quickly disappears introducing a small degree of stochasticity on the recurrence of earthquakes on a fault; (3) faults that are strongly coupled in terms of Coulomb failure function model are synchronized in time only in a marked deterministic framework, and as before, such a synchronization disappears introducing a small degree of stochasticity on the recurrence of earthquakes on a fault. Overall, the results show that even in a simple and perfectly known earthquake occurrence world, introducing a small degree of stochasticity may blur most of the deterministic time features, such as long-term trend and synchronization among nearby coupled faults.

Human performance cognitive-behavioral modeling: a benefit for occupational safety.

PubMed

Gore, Brian F

2002-01-01

Human Performance Modeling (HPM) is a computer-aided job analysis software methodology used to generate predictions of complex human-automation integration and system flow patterns with the goal of improving operator and system safety. The use of HPM tools has recently been increasing due to reductions in computational cost, augmentations in the tools' fidelity, and usefulness in the generated output. An examination of an Air Man-machine Integration Design and Analysis System (Air MIDAS) model evaluating complex human-automation integration currently underway at NASA Ames Research Center will highlight the importance to occupational safety of considering both cognitive and physical aspects of performance when researching human error.

Human performance cognitive-behavioral modeling: a benefit for occupational safety

NASA Technical Reports Server (NTRS)

Gore, Brian F.

2002-01-01

Human Performance Modeling (HPM) is a computer-aided job analysis software methodology used to generate predictions of complex human-automation integration and system flow patterns with the goal of improving operator and system safety. The use of HPM tools has recently been increasing due to reductions in computational cost, augmentations in the tools' fidelity, and usefulness in the generated output. An examination of an Air Man-machine Integration Design and Analysis System (Air MIDAS) model evaluating complex human-automation integration currently underway at NASA Ames Research Center will highlight the importance to occupational safety of considering both cognitive and physical aspects of performance when researching human error.

Unnatural selection: talent identification and development in sport.

PubMed

Abbott, Angela; Button, Chris; Pepping, Gert-Jan; Collins, Dave

2005-01-01

The early identification of talented individuals has become increasingly important across many performance domains. Current talent identification (TI) schemes in sport typically select on the basis of discrete, unidimensional measures at unstable periods in the athlete's development. In this article, the concept of talent is revised as a complex, dynamical system in which future behaviors emerge from an interaction of key performance determinants such as psychological behaviors, motor abilities, and physical characteristics. Key nonlinear dynamics concepts are related to TI approaches such as sensitivity to initial conditions, transitions, and exponential behavioral distributions. It is concluded that many TI models place an overemphasis on early identification rather than the development of potentially talented performers. A generic model of talent identification and development is proposed that addresses these issues and provides direction for future research.

Characteristics associated with Sleep Duration, Chronotype, and Social jet lag in Adolescents

PubMed Central

Malone, Susan Kohl; Zemel, Babette S.; Compher, Charlene; Souders, Margaret; Chittams, Jesse; Thompson, Aleda Leis; Lipman, Terri H.

2015-01-01

Sleep is a complex behavior with numerous health implications. Identifying socio-demographic and behavioral characteristics of sleep are important for determining those at greatest risk for sleep-related health disparities. In this cross-sectional study, general linear models were used to examine socio-demographic and behavioral characteristics associated with sleep duration, chronotype, and social jet lag in adolescents. One hundred fifteen participants completed Phase I (self-reported sleep measures); 69 of these participants completed Phase II (actigraphy-estimated sleep measures). Black adolescents had shorter free night sleep than Hispanics. Youth with later chronotypes ate fewer fruits and vegetables, drank more soda, were less physically active, and took more daytime naps. Based on these findings, recommendations for individual support and school policies are provided. PMID:26376832

Building Robota, a mini-humanoid robot for the rehabilitation of children with autism.

PubMed

Billard, Aude; Robins, Ben; Nadel, Jacqueline; Dautenhahn, Kerstin

2007-01-01

The Robota project constructs a series of multiple-degrees-of-freedom, doll-shaped humanoid robots, whose physical features resemble those of a human baby. The Robota robots have been applied as assistive technologies in behavioral studies with low-functioning children with autism. These studies investigate the potential of using an imitator robot to assess children's imitation ability and to teach children simple coordinated behaviors. In this article, the authors review the recent technological developments that have made the Robota robots suitable for use with children with autism. They critically appraise the main outcomes of two sets of behavioral studies conducted with Robota and discuss how these results inform future development of the Robota robots and robots in general for the rehabilitation of children with complex developmental disabilities.

Learning the Task Management Space of an Aircraft Approach Model

NASA Technical Reports Server (NTRS)

Krall, Joseph; Menzies, Tim; Davies, Misty

2014-01-01

Validating models of airspace operations is a particular challenge. These models are often aimed at finding and exploring safety violations, and aim to be accurate representations of real-world behavior. However, the rules governing the behavior are quite complex: nonlinear physics, operational modes, human behavior, and stochastic environmental concerns all determine the responses of the system. In this paper, we present a study on aircraft runway approaches as modeled in Georgia Tech's Work Models that Compute (WMC) simulation. We use a new learner, Genetic-Active Learning for Search-Based Software Engineering (GALE) to discover the Pareto frontiers defined by cognitive structures. These cognitive structures organize the prioritization and assignment of tasks of each pilot during approaches. We discuss the benefits of our approach, and also discuss future work necessary to enable uncertainty quantification.

Change in explicit and implicit motivation toward physical activity and sedentary behavior in pulmonary rehabilitation and associations with postrehabilitation behaviors.

PubMed

Chevance, Guillaume; Héraud, Nelly; Varray, Alain; Boiché, Julie

2017-05-01

The aim of this study was twofold: (a) to determine whether Theory of Planned Behavior (TPB) variables and implicit attitudes toward physical activity and sedentary behavior would change during a 5-week pulmonary rehabilitation (PR) program, and (b) to investigate the relationships between behavioral intentions, implicit attitudes, physical activity, and sedentary behavior in postrehabilitation. Out of 142 patients with respiratory disease included in this study, 119 completed 2 questionnaires measuring TPB variables with regard to physical activity and sedentary behavior, and an Implicit Association Test (IAT) measuring implicit attitudes toward physical activity in contrast to sedentary behavior. The TPB questionnaires and the IAT were administered at the beginning (Time 1) and the end of the program (Time 2). Six months after the program (Time 3), 62 patients provided self-reported measures of their recreational physical activity and screen-based, leisure-time sedentary behavior. Over the course of pulmonary rehabilitation, perceived behavioral control and intentions toward physical activity increased, as did social norms and perceived behavioral control toward sedentary behavior; implicit attitudes were also more positive toward physical activity. Implicit attitudes at the end of PR (Time 2) were significantly associated with postrehabilitation physical activity (Time 3). TPB variables toward physical activity and sedentary behavior as well as implicit attitudes were enhanced during PR. At 6 months, implicit attitudes were significantly associated with physical activity. These results suggest that motivation, particularly implicit attitudes, should be targeted in future behavioral interventions in order to optimize the effects of rehabilitation on physical activity maintenance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Ghost in the Machine: Fracking in the Earth's Complex Brittle Crust

NASA Astrophysics Data System (ADS)

Malin, P. E.

2015-12-01

This paper discusses in the impact of complex rock properties on practical applications like fracking and its associated seismic emissions. A variety of borehole measurements show that the complex physical properties of the upper crust cannot be characterized by averages on any scale. Instead they appear to follow 3 empirical rule: a power law distribution in physical scales, a lognormal distribution in populations, and a direct relation between changes in porosity and log(permeability). These rules can be directly related to the presence of fluid rich and seismically active fractures - from mineral grains to fault segments. (These are the "ghosts" referred to in the title.) In other physical systems, such behaviors arise on the boundaries of phase changes, and are studied as "critical state physics". In analogy to the 4 phases of water, crustal rocks progress upward from a un-fractured, ductile lower crust to nearly cohesionless surface alluvium. The crust in between is in an unstable transition. It is in this layer methods such as hydrofracking operate - be they in Oil and Gas, geothermal, or mining. As a result, nothing is predictable in these systems. Crustal models have conventionally been constructed assuming that in situ permeability and related properties are normally distributed. This approach is consistent with the use of short scale-length cores and logs to estimate properties. However, reservoir-scale flow data show that they are better fit to lognormal distributions. Such "long tail" distributions are observed for well productivity, ore vein grades, and induced seismic signals. Outcrop and well-log data show that many rock properties also show a power-law-type variation in scale lengths. In terms of Fourier power spectra, if peaks per km is k, then their power is proportional to 1/k. The source of this variation is related to pore-space connectivity, beginning with grain-fractures. We then show that a passive seismic method, Tomographic Fracture ImagingTM (TFI), can observe the distribution of this connectivity. Combined with TFI data, our fracture-connectivity model reveals the most significant crustal features and account for their range of passive and stimulated behaviors.

Preventing Childhood Caries

PubMed Central

Albino, J.; Tiwari, T.

2016-01-01

The etiology of dental caries reflects a complex interplay of biochemical, microbial, genetic, social and physical environmental, and health-influencing behavioral factors. This review updates the literature on the efficacy of behavioral approaches to caries prevention for children up to 18 y of age. Included were studies of behavioral interventions implemented at individual, family, and community levels that assessed results in terms of reductions in caries increments. Only those reports published since 2011 were considered. Outcomes were variable, although motivational interviewing, which involves individuals in decisions about oral health within the context of their respective life circumstances, proved effective in 3 of 4 reported studies, and more definitive trials are underway. Recommendations for future research include examinations of the cost-effectiveness of interventions, as well as work focused on understanding the mechanisms underlying oral health behavior change and variables that may mediate or moderate responses to interventions. PMID:26438210

Statistical physics of human cooperation

NASA Astrophysics Data System (ADS)

Perc, Matjaž; Jordan, Jillian J.; Rand, David G.; Wang, Zhen; Boccaletti, Stefano; Szolnoki, Attila

2017-05-01

Extensive cooperation among unrelated individuals is unique to humans, who often sacrifice personal benefits for the common good and work together to achieve what they are unable to execute alone. The evolutionary success of our species is indeed due, to a large degree, to our unparalleled other-regarding abilities. Yet, a comprehensive understanding of human cooperation remains a formidable challenge. Recent research in the social sciences indicates that it is important to focus on the collective behavior that emerges as the result of the interactions among individuals, groups, and even societies. Non-equilibrium statistical physics, in particular Monte Carlo methods and the theory of collective behavior of interacting particles near phase transition points, has proven to be very valuable for understanding counterintuitive evolutionary outcomes. By treating models of human cooperation as classical spin models, a physicist can draw on familiar settings from statistical physics. However, unlike pairwise interactions among particles that typically govern solid-state physics systems, interactions among humans often involve group interactions, and they also involve a larger number of possible states even for the most simplified description of reality. The complexity of solutions therefore often surpasses that observed in physical systems. Here we review experimental and theoretical research that advances our understanding of human cooperation, focusing on spatial pattern formation, on the spatiotemporal dynamics of observed solutions, and on self-organization that may either promote or hinder socially favorable states.

Self-efficacy mediates the relationship between behavioral processes of change and physical activity in older breast cancer survivors.

PubMed

Loprinzi, Paul D; Cardinal, Bradley J

2013-01-01

The degree to which breast cancer survivors use behavioral processes of change has not been investigated. Additionally, the relationship between behavioral processes and other theory-based mediators of adult physical activity behavior has not been extensively studied among breast cancer survivors. The objectives of this study were to: (1) determine the extent to which breast cancer survivors use behavioral processes associated with physical activity behavior change, and (2) examine the inter-relationships between behavioral processes, self-efficacy, and physical activity behavior among breast cancer survivors. Sixty-nine breast cancer survivors completed surveys examining behavioral processes and exercise-specific self-efficacy. Six months later they completed a self-report physical activity questionnaire. Findings showed the majority of breast cancer survivors did not use approximately half of the behavioral processes on a regular basis, and self-efficacy completely mediated the relationship between behavioral processes and physical activity. Health care professionals may help enhance self-efficacy and ultimately increase physical activity behavior in breast cancer survivors by teaching behavior skills such as enlisting social support.

Implementing a modeling software for animated protein-complex interactions using a physics simulation library.

PubMed

Ueno, Yutaka; Ito, Shuntaro; Konagaya, Akihiko

2014-12-01

To better understand the behaviors and structural dynamics of proteins within a cell, novel software tools are being developed that can create molecular animations based on the findings of structural biology. This study proposes our method developed based on our prototypes to detect collisions and examine the soft-body dynamics of molecular models. The code was implemented with a software development toolkit for rigid-body dynamics simulation and a three-dimensional graphics library. The essential functions of the target software system included the basic molecular modeling environment, collision detection in the molecular models, and physical simulations of the movement of the model. Taking advantage of recent software technologies such as physics simulation modules and interpreted scripting language, the functions required for accurate and meaningful molecular animation were implemented efficiently.

High Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

DOE PAGES

Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

2014-07-28

The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space, and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing are essential for accurately modeling them. In the past decade, the US Department of Energy's SciDAC program has produced accelerator-modeling tools that have been employed to tackle some of the most difficult accelerator science problems. The authors discuss the Synergia framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable ofmore » handling the entire spectrum of beam dynamics simulations. Our authors present Synergia's design principles and its performance on HPC platforms.« less

The Importance of Protons in Reactive Transport Modeling

NASA Astrophysics Data System (ADS)

McNeece, C. J.; Hesse, M. A.

2014-12-01

The importance of pH in aqueous chemistry is evident; yet, its role in reactive transport is complex. Consider a column flow experiment through silica glass beads. Take the column to be saturated and flowing with solution of a distinct pH. An instantaneous change in the influent solution pH can yield a breakthrough curve with both a rarefaction and shock component (composite wave). This behavior is unique among aqueous ions in transport and is more complex than intuition would tell. Analysis of the hyperbolic limit of this physical system can explain these first order transport phenomenon. This analysis shows that transport behavior is heavily dependent on the shape of the adsorption isotherm. Hence it is clear that accurate surface chemistry models are important in reactive transport. The proton adsorption isotherm has nonconstant concavity due to the proton's ability to partition into hydroxide. An eigenvalue analysis shows that an inflection point in the adsorption isotherm allows the development of composite waves. We use electrostatic surface complexation models to calculate realistic proton adsorption isotherms. Surface characteristics such as specific surface area, and surface site density were determined experimentally. We validate the model by comparison against silica glass bead flow through experiments. When coupled to surface complexation models, the transport equation captures the timing and behavior of breakthrough curves markedly better than with commonly used Langmuir assumptions. Furthermore, we use the adsorption isotherm to predict, a priori, the transport behavior of protons across pH composition space. Expansion of the model to multicomponent systems shows that proton adsorption can force composite waves to develop in the breakthrough curves of ions that would not otherwise exhibit such behavior. Given the abundance of reactive surfaces in nature and the nonlinearity of chemical systems, we conclude that building a greater understanding of proton adsorption is of utmost importance to reactive transport modeling.

[Prevention of overweight and obesity in children and adolescents : Critical appraisal of the evidence base].

PubMed

Pigeot, Iris; Baranowski, Tom; Lytle, Leslie; Ahrens, Wolfgang

2016-11-01

Despite careful planning and implementation, overweight/obesity prevention interventions in children and adolescents typically show no, inconsistent or merely weak effects. Such programs usually aim at behavior changes, rarely also at environmental changes, that draw upon conventional wisdom regarding the commonly accepted determinants of childhood overweight/obesity. This paper evaluates the evidence base of the apparently overweight-/obesity-related determinants diet, physical activity and stress. The results of international intervention studies are discussed against this background. Based on the mediating-moderating variable model, we investigate the effect of theory specified mediating variables and how potential moderating variables may impact these relationships. Contrary to common beliefs, recent research has revealed inconsistent evidence regarding associations between potentially obesogenic behaviors and overweight/obesity in youth. Moreover, the evidence for strong and causal relationships between mediating variables and targeted behaviors seems to be inconsistent. In addition, inadequate attention is paid to moderating effects. The etiology of overweight/obesity in youth is likely the result of a complex interplay of multi-causal influences. Future prevention interventions would benefit from a more thorough understanding of the complex relationships that have been hypothesized and of the mechanisms of suspected behaviors for affecting overweight/obesity. Only if substantial change can be demonstrated in mediators with reasonable effort under real world circumstances, it will make sense to progress to community behavior change trials.

Friendship networks and physical activity and sedentary behavior among youth: a systematized review.

PubMed

Sawka, Keri Jo; McCormack, Gavin R; Nettel-Aguirre, Alberto; Hawe, Penelope; Doyle-Baker, Patricia K

2013-12-01

Low levels of physical activity and increased participation in sedentary leisure-time activities are two important obesity-risk behaviors that impact the health of today's youth. Friend's health behaviors have been shown to influence individual health behaviors; however, current evidence on the specific role of friendship networks in relation to levels of physical activity and sedentary behavior is limited. The purpose of this review was to summarize evidence on friendship networks and both physical activity and sedentary behavior among children and adolescents. After a search of seven scientific databases and reference scans, a total of thirteen articles were eligible for inclusion. All assessed the association between friendship networks and physical activity, while three also assessed sedentary behavior. Overall, higher levels of physical activity among friends are associated with higher levels of physical activity of the individual. Longitudinal studies reveal that an individual's level of physical activity changes to reflect his/her friends' higher level of physical activity. Boys tend to be influenced by their friendship network to a greater extent than girls. There is mixed evidence surrounding a friend's sedentary behavior and individual sedentary behavior. Friends' physical activity level appears to have a significant influence on individual's physical activity level. Evidence surrounding sedentary behavior is limited and mixed. Results from this review could inform effective public health interventions that harness the influence of friends to increase physical activity levels among children and adolescents.

The physical model for research of behavior of grouting mixtures

NASA Astrophysics Data System (ADS)

Hajovsky, Radovan; Pies, Martin; Lossmann, Jaroslav

2016-06-01

The paper deals with description of physical model designed for verification of behavior of grouting mixtures when applied below underground water level. Described physical model has been set up to determine propagation of grouting mixture in a given environment. Extension of grouting in this environment is based on measurement of humidity and temperature with the use of combined sensors located within preinstalled special measurement probes around grouting needle. Humidity was measured by combined capacity sensor DTH-1010, temperature was gathered by a NTC thermistor. Humidity sensors measured time when grouting mixture reached sensor location point. NTC thermistors measured temperature changes in time starting from initial of injection. This helped to develop 3D map showing the distribution of grouting mixture through the environment. Accomplishment of this particular measurement was carried out by a designed primary measurement module capable of connecting 4 humidity and temperature sensors. This module also takes care of converting these physical signals into unified analogue signals consequently brought to the input terminals of analogue input of programmable automation controller (PAC) WinPAC-8441. This controller ensures the measurement itself, archiving and visualization of all data. Detail description of a complex measurement system and evaluation in form of 3D animations and graphs is supposed to be in a full paper.

ECCE Toolkit: Prototyping Sensor-Based Interaction.

PubMed

Bellucci, Andrea; Aedo, Ignacio; Díaz, Paloma

2017-02-23

Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems), a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit.

Uncertainty Quantification in Aeroelasticity

NASA Astrophysics Data System (ADS)

Beran, Philip; Stanford, Bret; Schrock, Christopher

2017-01-01

Physical interactions between a fluid and structure, potentially manifested as self-sustained or divergent oscillations, can be sensitive to many parameters whose values are uncertain. Of interest here are aircraft aeroelastic interactions, which must be accounted for in aircraft certification and design. Deterministic prediction of these aeroelastic behaviors can be difficult owing to physical and computational complexity. New challenges are introduced when physical parameters and elements of the modeling process are uncertain. By viewing aeroelasticity through a nondeterministic prism, where key quantities are assumed stochastic, one may gain insights into how to reduce system uncertainty, increase system robustness, and maintain aeroelastic safety. This article reviews uncertainty quantification in aeroelasticity using traditional analytical techniques not reliant on computational fluid dynamics; compares and contrasts this work with emerging methods based on computational fluid dynamics, which target richer physics; and reviews the state of the art in aeroelastic optimization under uncertainty. Barriers to continued progress, for example, the so-called curse of dimensionality, are discussed.

ECCE Toolkit: Prototyping Sensor-Based Interaction

PubMed Central

Bellucci, Andrea; Aedo, Ignacio; Díaz, Paloma

2017-01-01

Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems), a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit. PMID:28241502

Management and Treatment of Temporomandibular Disorders: A Clinical Perspective

PubMed Central

Wright, Edward F.; North, Sarah L.

2009-01-01

A temporomandibular disorder (TMD) is a very common problem affecting up to 33% of individuals within their lifetime. TMD is often viewed as a repetitive motion disorder of the masticatory structures and has many similarities to musculoskeletal disorders of other parts of the body. Treatment often involves similar principles as other regions as well. However, patients with TMD and concurrent cervical pain exhibit a complex symptomatic behavior that is more challenging than isolated TMD symptoms. Although routinely managed by medical and dental practitioners, TMD may be more effectively cared for when physical therapists are involved in the treatment process. Hence, a listing of situations when practitioners should consider referring TMD patients to a physical therapist can be provided to the practitioners in each physical therapist's region. This paper should assist physical therapists with evaluating, treating, insurance billing, and obtaining referrals for TMD patients. PMID:20140156

System-level musings about system-level science (Invited)

NASA Astrophysics Data System (ADS)

Liu, W.

2009-12-01

In teleology, a system has a purpose. In physics, a system has a tendency. For example, a mechanical system has a tendency to lower its potential energy. A thermodynamic system has a tendency to increase its entropy. Therefore, if geospace is seen as a system, what is its tendency? Surprisingly or not, there is no simple answer to this question. Or, to flip the statement, the answer is complex, or complexity. We can understand generally why complexity arises, as the geospace boundary is open to influences from the solar wind and Earth’s atmosphere and components of the system couple to each other in a myriad of ways to make the systemic behavior highly nonlinear. But this still begs the question: What is the system-level approach to geospace science? A reductionist view might assert that as our understanding of a component or subsystem progresses to a certain point, we can couple some together to understand the system on a higher level. However, in practice, a subsystem can almost never been observed in isolation with others. Even if such is possible, there is no guarantee that the subsystem behavior will not change when coupled to others. Hence, there is no guarantee that a subsystem, such as the ring current, has an innate and intrinsic behavior like a hydrogen atom. An absolutist conclusion from this logic can be sobering, as one would have to trace a flash of aurora to the nucleosynthesis in the solar core. The practical answer, however, is more promising; it is a mix of the common sense we call reductionism and awareness that, especially when strongly coupled, subsystems can experience behavioral changes, breakdowns, and catastrophes. If the stock answer to the systemic tendency of geospace is complexity, the objective of the system-level approach to geospace science is to define, measure, and understand this complexity. I will use the example of magnetotail dynamics to illuminate some key points in this talk.

Remote sensing supported surveillance and characterization of tailings behavior at a gold mine site, Finland.

NASA Astrophysics Data System (ADS)

Rauhala, Anssi; Tuomela, Anne; Rossi, Pekka M.; Davids, Corine

2017-04-01

The management of vast amounts of tailings produced is one of the key issues in mining operations. The effective and economic disposal of the waste requires knowledge concerning both basic physical properties of the tailings as well as more complex aspects such as consolidation behavior. The behavior of tailings in itself is a very complex issue that can be affected by flocculation, sedimentation, consolidation, segregation, deposition, freeze-thaw, and desiccation phenomena. The utilization of remote sensing in an impoundment-scale monitoring of tailings could benefit the management of tailings, and improve our knowledge on tailings behavior. In order to gain better knowledge of tailings behavior in cold climate, we have utilized both modern remote sensing techniques and more traditional in situ and laboratory measurements in characterizing thickened gold tailings behavior at a Finnish gold mine site, where the production has been halted due to low gold prices. The remote sensing measurements consisted of elevation datasets collected from unmanned aerial vehicles during summers 2015 and 2016, and a further campaign is planned for the summer 2017. The ongoing traditional measurements include for example particle-size distribution, frost heave, frost depth, water retention, temperature profile, and rheological measurements. Initial results from the remote sensing indicated larger than expected settlements on parts of the tailings impoundment, and also highlighted some of the complexities related to data processing. The interpretation of the results and characterization of the behavior is in this case complicated by possible freeze-thaw effects and potential settlement of the impoundment bottom structure consisting of natural peat. Experiments with remote sensing and unmanned aerial vehicles indicate that they could offer potential benefits in frequent mine site monitoring, but there is a need towards more robust and streamlined data acquisition and processing. The gathered data and obtained results form the basis for further modelling efforts which aim at better management of tailings storage facilities.

An ocean scatter propagation model for aeronautical satellite communication applications

NASA Technical Reports Server (NTRS)

Moreland, K. W.

1990-01-01

In this paper an ocean scattering propagation model, developed for aircraft-to-satellite (aeronautical) applications, is described. The purpose of the propagation model is to characterize the behavior of sea reflected multipath as a function of physical propagation path parameters. An accurate validation against the theoretical far field solution for a perfectly conducting sinusoidal surface is provided. Simulation results for typical L band aeronautical applications with low complexity antennas are presented.

Behavioral health coaching for rural veterans with diabetes and depression: a patient randomized effectiveness implementation trial.

PubMed

Cully, Jeffrey A; Breland, Jessica Y; Robertson, Suzanne; Utech, Anne E; Hundt, Natalie; Kunik, Mark E; Petersen, Nancy J; Masozera, Nicholas; Rao, Radha; Naik, Aanand D

2014-04-28

Depression and diabetes cause significant burden for patients and the healthcare system and, when co-occurring, result in poorer self-care behaviors and worse glycemic control than for either condition alone. However, the clinical management of these comorbid conditions is complicated by a host of patient, provider, and system-level barriers that are especially problematic for patients in rural locations. Patient-centered medical homes provide an opportunity to integrate mental and physical health care to address the multifaceted needs of complex comorbid conditions. Presently, there is a need to not only develop robust clinical interventions for complex medically ill patients but also to find feasible ways to embed these interventions into the frontlines of existing primary care practices. This randomized controlled trial uses a hybrid effectiveness-implementation design to evaluate the Healthy Outcomes through Patient Empowerment (HOPE) intervention, which seeks to simultaneously address diabetes and depression for rural veterans in Southeast Texas. A total of 242 Veterans with uncontrolled diabetes and comorbid symptoms of depression will be recruited and randomized to either the HOPE intervention or to a usual-care arm. Participants will be evaluated on a host of diabetes and depression-related measures at baseline and 6- and 12-month follow-up. The trial has two primary goals: 1) to examine the effectiveness of the intervention on both physical (diabetes) and emotional health (depression) outcomes and 2) to simultaneously pilot test a multifaceted implementation strategy designed to increase fidelity and utilization of the intervention by coaches interfacing within the primary care setting. This ongoing blended effectiveness-implementation design holds the potential to advance the science and practice of caring for complex medically ill patients within the constraints of a busy patient-centered medical home. Behavioral Activation Therapy for Rural Veterans with Diabetes and Depression: NCT01572389.

Effects of Task Complexity on L2 Writing Behaviors and Linguistic Complexity

ERIC Educational Resources Information Center

Révész, Andrea; Kourtali, Nektaria-Efstathia; Mazgutova, Diana

2017-01-01

This study investigated whether task complexity influences second language (L2) writers' fluency, pausing, and revision behaviors and the cognitive processes underlying these behaviors; whether task complexity affects linguistic complexity of written output; and whether relationships between writing behaviors and linguistic complexity are…

Complexity of childhood sexual abuse: predictors of current post-traumatic stress disorder, mood disorders, substance use, and sexual risk behavior among adult men who have sex with men.

PubMed

Boroughs, Michael S; Valentine, Sarah E; Ironson, Gail H; Shipherd, Jillian C; Safren, Steven A; Taylor, S Wade; Dale, Sannisha K; Baker, Joshua S; Wilner, Julianne G; O'Cleirigh, Conall

2015-10-01

Men who have sex with men (MSM) are the group most at risk for HIV and represent the majority of new infections in the United States. Rates of childhood sexual abuse (CSA) among MSM have been estimated as high as 46 %. CSA is associated with increased risk of HIV and greater likelihood of HIV sexual risk behavior. The purpose of this study was to identify the relationships between CSA complexity indicators and mental health, substance use, sexually transmitted infections, and HIV sexual risk among MSM. MSM with CSA histories (n = 162) who were screened for an HIV prevention efficacy trial completed comprehensive psychosocial assessments. Five indicators of complex CSA experiences were created: CSA by family member, CSA with penetration, CSA with physical injury, CSA with intense fear, and first CSA in adolescence. Adjusted regression models were used to identify relationships between CSA complexity and outcomes. Participants reporting CSA by family member were at 2.6 odds of current alcohol use disorder (OR 2.64: CI 1.24-5.63), two times higher odds of substance use disorder (OR 2.1: CI 1.02-2.36), and 2.7 times higher odds of reporting an STI in the past year (OR 2.7: CI 1.04-7.1). CSA with penetration was associated with increased likelihood of current PTSD (OR 3.17: CI 1.56-6.43), recent HIV sexual risk behavior (OR 2.7: CI 1.16-6.36), and a greater number of casual sexual partners (p = 0.02). Both CSA with Physical Injury (OR 4.05: CI 1.9-8.7) and CSA with Intense Fear (OR 5.16: CI 2.5-10.7) were related to increased odds for current PTSD. First CSA in adolescence was related to increased odds of major depressive disorder. These findings suggest that CSA, with one or more complexities, creates patterns of vulnerabilities for MSM, including post-traumatic stress disorder, substance use, and sexual risk taking, and suggests the need for detailed assessment of CSA and the development of integrated HIV prevention programs that address mental health and substance use comorbidities.

Complexity of childhood sexual abuse: Predictors of current PTSD, mood disorders, substance use, and sexual risk behavior among adult men who have sex with men

PubMed Central

Boroughs, Michael S.; Valentine, Sarah E.; Ironson, Gail H.; Shipherd, Jillian C.; Safren, Steven A.; Taylor, S. Wade; Dale, Sannisha K.; Baker, Joshua S.; Wilner, Julianne G.; O'Cleirigh, Conall

2016-01-01

Men who have sex with men (MSM) are the group most at risk for HIV and represent the majority of new infections in the United States. Rates of childhood sexual abuse (CSA) among MSM have been estimated as high as 46%. CSA is associated with increased risk of HIV and greater likelihood of HIV sexual risk behavior. The purpose of this study was to identify the relationships between CSA complexity indicators and mental health, substance use, sexually transmitted infections (STIs) and HIV sexual risk among MSM. MSM with CSA histories (n = 162) who were screened for an HIV-prevention efficacy trial completed comprehensive psychosocial assessments. Five indicators of complex CSA experiences were created: CSA by family member, CSA with penetration, CSA with physical injury, CSA with intense fear, and first CSA in adolescence. Adjusted regression models were used to identify relationships between CSA complexity and outcomes. Participants reporting CSA by family member were at 2.6 odds of current alcohol use disorder (OR: 2.64: CI 1.24 – 5.63), 2 times higher odds of substance use disorder (OR 2.1: CI 1.02 – 2.36), and 2.7 times higher odds of reporting an STI in the past year (OR 2.7: CI 1.04 – 7.1). CSA with penetration was associated with increased likelihood of current PTSD (OR 3.17: CI 1.56 – 6.43), recent HIV sexual risk behavior (OR 2.7: CI 1.16 – 6.36) and a greater number of casual sexual partners (p = .02). Both CSA with Physical Injury (OR 4.05: CI 1.9 – 8.7) and CSA with Intense Fear (OR 5.16: CI 2.5 – 10.7) were related to increased odds for current PTSD. First CSA in adolescence was related to increased odds of major depressive disorder. These findings suggest that CSA, with one or more complexities, creates patterns of vulnerabilities for MSM, including PTSD, substance use, and sexual risk taking and suggests the need for detailed assessment of CSA and the development of integrated HIV prevention programs that address mental health and substance use comorbidities. PMID:26159863

Giant crystal-electric-field effect and complex magnetic behavior in single-crystalline CeRh3Si2

NASA Astrophysics Data System (ADS)

Pikul, A. P.; Kaczorowski, D.; Gajek, Z.; Stȩpień-Damm, J.; Ślebarski, A.; Werwiński, M.; Szajek, A.

2010-05-01

Single-crystalline CeRh3Si2 was investigated by means of x-ray diffraction, magnetic susceptibility, magnetization, electrical resistivity, and specific-heat measurements carried out in wide temperature and magnetic field ranges. Moreover, the electronic structure of the compound was studied at room temperature by cerium core-level x-ray photoemission spectroscopy (XPS). The physical properties were analyzed in terms of crystalline electric field and compared with results of ab initio band-structure calculations performed within the density-functional theory approach. The compound was found to crystallize in the orthorhombic unit cell of the ErRh3Si2 type (space group Imma No.74, Pearson symbol: oI24 ) with the lattice parameters a=7.1330(14)Å , b=9.7340(19)Å , and c=5.6040(11)Å . Analysis of the magnetic and XPS data revealed the presence of well-localized magnetic moments of trivalent cerium ions. All the physical properties were found to be highly anisotropic over the whole temperature range studied and influenced by exceptionally strong crystalline electric field with the overall splitting of the 4f1 ground multiplet exceeding 5700 K. Antiferromagnetic order of the cerium magnetic moments at TN=4.70(1)K and their subsequent spin rearrangement at Tt=4.48(1)K manifest themselves as distinct anomalies in the temperature characteristic of all the physical properties investigated and exhibit complex evolution in an external magnetic field. A tentative magnetic B-T phase diagram, constructed for B parallel to the b axis being the easy magnetization direction, shows very complex magnetic behavior of CeRh3Si2 , similar to that recently reported for an isostructural compound CeIr3Si2 . The electronic band-structure calculations corroborated the antiferromagnetic ordering of the cerium magnetic moments and well-reproduced the experimental XPS valence-band spectrum.

Physical activity perceptions and behaviors among young adults with congenital heart disease: A mixed-methods study.

PubMed

McKillop, Adam; McCrindle, Brian W; Dimitropoulos, Gina; Kovacs, Adrienne H

2018-03-01

A physically active lifestyle can help maintain positive physical and psychosocial health outcomes among adults with congenital heart disease (CHD). This study explored the physical activity perceptions and behaviors among young adults with CHD. This was a cross-sectional, mixed-methods study that included objectively measured physical activity assessment (accelerometer), individual semistructured interviews, and psychosocial questionnaires. Fifteen participants (67% male; 21 ± 3 years old) with moderate (n = 10) or complex (n = 5) CHD were recruited from an outpatient adult CHD clinic. Participants accumulated 26 ± 16 minutes of moderate-to-vigorous physical activity per day, and reported a high quality of life, moderate self-efficacy for exercise, and low cardiac-focused anxiety. Qualitative data indicated that participants reported more positive perceptions toward activity if their family members encouraged physical activity participation, including siblings that engaged in physical activity alongside participants. Participants described parents as supportive rather than overprotective. Activity precautions were perceived by participants as being instructions from cardiologists rather than restrictions by parents. Participants described some physical limitations compared to peers, but managed challenges by either working within their limitations or choosing activities that met their expectations and/or in which they could fully participate. Participants often described childhood physical activity in the context of school, physical education, and organized sports. Whereas physical activity in childhood was viewed as recreational, the cardiac health-promoting aspects became more prominent in adulthood. Activities performed during one's employment were considered sufficient to meet physical activity recommendation levels, and participants reported limited time and/or energy to participate in activity outside of work. The influence of family appeared to help participants adopt a positive perception toward activity participation in childhood that was carried forward to young adulthood. Future clinical work should target adolescents with CHD with less social supports and/or negative perceptions toward physical activity. © 2017 Wiley Periodicals, Inc.

Virtual Reality As a Training Tool to Treat Physical Inactivity in Children.

PubMed

Kiefer, Adam W; Pincus, David; Richardson, Michael J; Myer, Gregory D

2017-01-01

Lack of adequate physical activity in children is an epidemic that can result in obesity and other poor health outcomes across the lifespan. Physical activity interventions focused on motor skill competence continue to be developed, but some interventions, such as neuromuscular training (NMT), may be limited in how early they can be implemented due to dependence on the child's level of cognitive and perceptual-motor development. Early implementation of motor-rich activities that support motor skill development in children is critical for the development of healthy levels of physical activity that carry through into adulthood. Virtual reality (VR) training may be beneficial in this regard. VR training, when grounded in an information-based theory of perceptual-motor behavior that modifies the visual information in the virtual world, can promote early development of motor skills in youth akin to more natural, real-world development as opposed to strictly formalized training. This approach can be tailored to the individual child and training scenarios can increase in complexity as the child develops. Ultimately, training in VR may help serve as a precursor to "real-world" NMT, and once the child reaches the appropriate training age can also augment more complex NMT regimens performed outside of the virtual environment.

Virtual Reality As a Training Tool to Treat Physical Inactivity in Children

PubMed Central

Kiefer, Adam W.; Pincus, David; Richardson, Michael J.; Myer, Gregory D.

2017-01-01

Lack of adequate physical activity in children is an epidemic that can result in obesity and other poor health outcomes across the lifespan. Physical activity interventions focused on motor skill competence continue to be developed, but some interventions, such as neuromuscular training (NMT), may be limited in how early they can be implemented due to dependence on the child’s level of cognitive and perceptual-motor development. Early implementation of motor-rich activities that support motor skill development in children is critical for the development of healthy levels of physical activity that carry through into adulthood. Virtual reality (VR) training may be beneficial in this regard. VR training, when grounded in an information-based theory of perceptual-motor behavior that modifies the visual information in the virtual world, can promote early development of motor skills in youth akin to more natural, real-world development as opposed to strictly formalized training. This approach can be tailored to the individual child and training scenarios can increase in complexity as the child develops. Ultimately, training in VR may help serve as a precursor to “real-world” NMT, and once the child reaches the appropriate training age can also augment more complex NMT regimens performed outside of the virtual environment. PMID:29376045

International perspectives on the physical inactivity crisis--structural solutions over evidence generation?

PubMed

Bauman, Adrian; Finegood, Diane T; Matsudo, Victor

2009-10-01

Many programs to increase physical activity have been evaluated in developed countries, where 'leisure time physical activity' is the most frequent domain for interventions. In developing countries, and also with reference to global obesity prevention, different kinds of interventions targeting 'total physical activity' are needed. This requires efforts across agencies and sectors, and in the domains of work, active transport, reduced sitting time, as well as leisure time physical activity promotion. In considering possible solutions, this commentary examined the use of complex systems, where integrated efforts across sectors and agencies might, in combination, contribute to increasing total physical activity. The key sets of actions required globally to increase physical activity were, in our opinion, [i] efforts to disseminate individual-level behavior change programs to reach much larger populations rather than volunteers, [ii] social marketing and mass communication campaigns to change social norms in the community and among professionals and policymakers, [iii] efforts to influence the social and physical environment to make them more conducive to physical activity, and [iv] the development and implementation of national physical activity plans and strategies, with sufficient timelines and resources to achieve measurable change.

The Internet As a Large-Scale Complex System

NASA Astrophysics Data System (ADS)

Park, Kihong; Willinger, Walter

2005-06-01

The Internet may be viewed as a "complex system" with diverse features and many components that can give rise to unexpected emergent phenomena, revealing much about its own engineering. This book brings together chapter contributions from a workshop held at the Santa Fe Institute in March 2001. This volume captures a snapshot of some features of the Internet that may be fruitfully approached using a complex systems perspective, meaning using interdisciplinary tools and methods to tackle the subject area. The Internet penetrates the socioeconomic fabric of everyday life; a broader and deeper grasp of the Internet may be needed to meet the challenges facing the future. The resulting empirical data have already proven to be invaluable for gaining novel insights into the network's spatio-temporal dynamics, and can be expected to become even more important when tryin to explain the Internet's complex and emergent behavior in terms of elementary networking-based mechanisms. The discoveries of fractal or self-similar network traffic traces, power-law behavior in network topology and World Wide Web connectivity are instances of unsuspected, emergent system traits. Another important factor at the heart of fair, efficient, and stable sharing of network resources is user behavior. Network systems, when habited by selfish or greedy users, take on the traits of a noncooperative multi-party game, and their stability and efficiency are integral to understanding the overall system and its dynamics. Lastly, fault-tolerance and robustness of large-scale network systems can exhibit spatial and temporal correlations whose effective analysis and management may benefit from rescaling techniques applied in certain physical and biological systems. The present book will bring together several of the leading workers involved in the analysis of complex systems with the future development of the Internet.

Applications of complex systems theory in nursing education, research, and practice.

PubMed

Clancy, Thomas R; Effken, Judith A; Pesut, Daniel

2008-01-01

The clinical and administrative processes in today's healthcare environment are becoming increasingly complex. Multiple providers, new technology, competition, and the growing ubiquity of information all contribute to the notion of health care as a complex system. A complex system (CS) is characterized by a highly connected network of entities (e.g., physical objects, people or groups of people) from which higher order behavior emerges. Research in the transdisciplinary field of CS has focused on the use of computational modeling and simulation as a methodology for analyzing CS behavior. The creation of virtual worlds through computer simulation allows researchers to analyze multiple variables simultaneously and begin to understand behaviors that are common regardless of the discipline. The application of CS principles, mediated through computer simulation, informs nursing practice of the benefits and drawbacks of new procedures, protocols and practices before having to actually implement them. The inclusion of new computational tools and their applications in nursing education is also gaining attention. For example, education in CSs and applied computational applications has been endorsed by The Institute of Medicine, the American Organization of Nurse Executives and the American Association of Colleges of Nursing as essential training of nurse leaders. The purpose of this article is to review current research literature regarding CS science within the context of expert practice and implications for the education of nurse leadership roles. The article focuses on 3 broad areas: CS defined, literature review and exemplars from CS research and applications of CS theory in nursing leadership education. The article also highlights the key role nursing informaticists play in integrating emerging computational tools in the analysis of complex nursing systems.

Physically elastic analysis of a cylindrical ring as a unit cell of a complete composite under applied stress in the complex plane using cubic polynomials

NASA Astrophysics Data System (ADS)

Monfared, Vahid

2018-03-01

Elastic analysis is analytically presented to predict the behaviors of the stress and displacement components in the cylindrical ring as a unit cell of a complete composite under applied stress in the complex plane using cubic polynomials. This analysis is based on the complex computation of the stress functions in the complex plane and polar coordinates. Also, suitable boundary conditions are considered and assumed to analyze along with the equilibrium equations and bi-harmonic equation. This method has some important applications in many fields of engineering such as mechanical, civil and material engineering generally. One of the applications of this research work is in composite design and designing the cylindrical devices under various loadings. Finally, it is founded that the convergence and accuracy of the results are suitable and acceptable through comparing the results.

Atg5- and Atg7-dependent autophagy in dopaminergic neurons regulates cellular and behavioral responses to morphine.

PubMed

Su, Ling-Yan; Luo, Rongcan; Liu, Qianjin; Su, Jing-Ran; Yang, Lu-Xiu; Ding, Yu-Qiang; Xu, Lin; Yao, Yong-Gang

2017-09-02

The molecular basis of chronic morphine exposure remains unknown. In this study, we hypothesized that macroautophagy/autophagy of dopaminergic neurons would mediate the alterations of neuronal dendritic morphology and behavioral responses induced by morphine. Chronic morphine exposure caused Atg5 (autophagy-related 5)- and Atg7 (autophagy-related 7)-dependent and dopaminergic neuron-specific autophagy resulting in decreased neuron dendritic spines and the onset of addictive behaviors. In cultured primary midbrain neurons, morphine treatment significantly reduced total dendritic length and complexity, and this effect could be reversed by knockdown of Atg5 or Atg7. Mice deficient for Atg5 or Atg7 specifically in the dopaminergic neurons were less sensitive to developing a morphine reward response, behavioral sensitization, analgesic tolerance and physical dependence compared to wild-type mice. Taken together, our findings suggested that the Atg5- and Atg7-dependent autophagy of dopaminergic neurons contributed to cellular and behavioral responses to morphine and may have implications for the future treatment of drug addiction.

Friendship networks and physical activity and sedentary behavior among youth: a systematized review

PubMed Central

2013-01-01

Background Low levels of physical activity and increased participation in sedentary leisure-time activities are two important obesity-risk behaviors that impact the health of today’s youth. Friend’s health behaviors have been shown to influence individual health behaviors; however, current evidence on the specific role of friendship networks in relation to levels of physical activity and sedentary behavior is limited. The purpose of this review was to summarize evidence on friendship networks and both physical activity and sedentary behavior among children and adolescents. Method After a search of seven scientific databases and reference scans, a total of thirteen articles were eligible for inclusion. All assessed the association between friendship networks and physical activity, while three also assessed sedentary behavior. Results Overall, higher levels of physical activity among friends are associated with higher levels of physical activity of the individual. Longitudinal studies reveal that an individual’s level of physical activity changes to reflect his/her friends’ higher level of physical activity. Boys tend to be influenced by their friendship network to a greater extent than girls. There is mixed evidence surrounding a friend’s sedentary behavior and individual sedentary behavior. Conclusion Friends’ physical activity level appears to have a significant influence on individual’s physical activity level. Evidence surrounding sedentary behavior is limited and mixed. Results from this review could inform effective public health interventions that harness the influence of friends to increase physical activity levels among children and adolescents. PMID:24289113

Evidence of nonextensive statistical physics behavior in the watershed distribution in active tectonic areas: examples from Greece

NASA Astrophysics Data System (ADS)

Vallianatos, Filippos; Kouli, Maria

2013-08-01

The Digital Elevation Model (DEM) for the Crete Island with a resolution of approximately 20 meters was used in order to delineate watersheds by computing the flow direction and using it in the Watershed function. The Watershed function uses a raster of flow direction to determine contributing area. The Geographic Information Systems routine procedure was applied and the watersheds as well as the streams network (using a threshold of 2000 cells, i.e. the minimum number of cells that constitute a stream) were extracted from the hydrologically corrected (free of sinks) DEM. A number of a few thousand watersheds were delineated, and their areal extent was calculated. From these watersheds a number of 300 was finally selected for further analysis as the watersheds of extremely small area were excluded in order to avoid possible artifacts. Our analysis approach is based on the basic principles of Complexity theory and Tsallis Entropy introduces in the frame of non-extensive statistical physics. This concept has been successfully used for the analysis of a variety of complex dynamic systems including natural hazards, where fractality and long-range interactions are important. The analysis indicates that the statistical distribution of watersheds can be successfully described with the theoretical estimations of non-extensive statistical physics implying the complexity that characterizes the occurrences of them.

Task Performance and Meta-Cognitive Outcomes When Using Activity Workstations and Traditional Desks

PubMed Central

Pilcher, June J.; Baker, Victoria C.

2016-01-01

The purpose of the current study is to compare the effects of light physical activity to sedentary behavior on cognitive task performance and meta-cognitive responses. Thirty-eight undergraduate students participated in the study. The participants used a stationary bicycle with a desk top and a traditional desk while completing two complex cognitive tasks and measures of affect, motivation, morale, and engagement. The participants pedaled the stationary bicycle at a slow pace (similar in exertion to a normal walking pace) while working. The results indicated that cognitive task performance did not change between the two workstations. However, positive affect, motivation, and morale improved when using the stationary bicycle. These results suggest that activity workstations could be implemented in the work place and in educational settings to help decrease sedentary behavior without negatively affecting performance. Furthermore, individuals could experience a positive emotional response when working on activity workstations which in turn could help encourage individuals to choose to be more physical active during daily activities. PMID:27445921

Elder Mistreatment among Chinese and Korean Immigrants: The Roles of Sociocultural Contexts on Perceptions and Help-Seeking Behaviors

PubMed Central

LEE, YEON-SHIM; KAPLAN, CELIA P.; PEREZ-STABLE, ELISEO J.

2014-01-01

The purpose of this study was to identify dimensions of elder mistreatment in Chinese and Korean immigrant communities and to increase sociocultural understanding of such mistreatment by elucidating the complexities of abuse embedded in unique social and cultural contexts. In-depth interviews were conducted with 20 local professionals working primarily in Asian elderly advocacy, and six focus group discussions were conducted involving 60 community members in the San Francisco Bay area. Five dimensions of elder mistreatment were identified: psychological abuse, neglect by a trusted person, financial exploitation, physical abuse, and sexual abuse. In general, fewer Korean community member participants reported having observed physical or financial abuse than Chinese groups, but they reported greater knowledge of situations involving psychological abuse, neglect by a trusted person, and sexual abuse. The contexts of cultural influences and immigration and acculturation were salient themes that shaped participants’ subjective perceptions and beliefs about elder abuse and hence help-seeking behaviors. PMID:24779539

Elder Mistreatment among Chinese and Korean Immigrants: The Roles of Sociocultural Contexts on Perceptions and Help-Seeking Behaviors

PubMed Central

Lee, Yeon-Shim; Kaplan, Celia P.; Perez-Stable, Eliseo J.

2014-01-01

The purpose of this study was to identify dimensions of elder mistreatment in Chinese and Korean immigrant communities and to increase sociocultural understanding of such mistreatment by elucidating the complexities of abuse embedded in unique social and cultural contexts. In-depth interviews were conducted with 20 local professionals working primarily in Asian elderly advocacy, and six focus group discussions were conducted involving 60 community members in the San Francisco Bay area. Five dimensions of elder mistreatment were identified: psychological abuse, neglect by a trusted person, financial exploitation, physical abuse, and sexual abuse. In general, fewer Korean community member participants reported having observed physical or financial abuse than Chinese groups, but they reported greater knowledge of situations involving psychological abuse, neglect by a trusted person, and sexual abuse. The contexts of cultural influences and immigration and acculturation were salient themes that shaped participants’ subjective perceptions and beliefs about elder abuse and hence help-seeking behaviors. PMID:25431530

Systematic Review of the Effectiveness of Occupational Therapy–Related Interventions for People With Parkinson’s Disease

PubMed Central

Foster, Erin R.; Bedekar, Mayuri

2014-01-01

We describe the results of a systematic review of the literature on occupational therapy–related interventions for people with Parkinson’s disease (PD). Three broad categories of intervention emerged: (1) exercise or physical activity; (2) environmental cues, stimuli, and objects; and (3) self-management and cognitive–behavioral strategies. Moderate to strong evidence exists for task-specific benefits of targeted physical activity training on motor performance, postural stability, and balance. Low to moderate evidence indicates that more complex, multimodal activity training supports improvement in functional movement activities. The evidence is moderate that the use of external supports during functional mobility or other movement activities has positive effects on motor control. In addition, moderate evidence is available that individualized interventions focused on promoting participant wellness initiatives and personal control by means of cognitive–behavioral strategies can improve targeted areas of quality of life. The implications for practice, education, and research are discussed. PMID:24367954

Trauma and homelessness in youth: Psychopathology and intervention.

PubMed

Davies, Benjamin R; Allen, Nicholas B

2017-06-01

Youth runaway behavior and homelessness (RHY) in the U.S. is increasingly common, with prevalence estimated at 1-1.7 million youth. RHY have multiple, overlapping problems often including poor physical and mental health, frequent street victimization, and histories of physical and sexual abuse. Further, current street victimization interacts with childhood abuse to produce complex, unique presentations of traumatic symptoms and related disorders in runaway and homeless youth. This review paper explores (1) the role of childhood trauma in the genesis of runaway and homeless behavior, and (2) how childhood trauma interacts with street victimization to create vulnerability to psychopathology. In response to the trauma needs of RHY, we conducted a systematic review of the state of the current literature on trauma-informed interventions for RHY. We conclude that the field currently lacks empirically validated trauma interventions in RHY. However, theoretically plausible frameworks do exist and could be the basis for future research and intervention development. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Middey, Srimanta; Chakhalian, J.; Mahadevan, P.

The electronic structure of transition metal oxides featuring correlated electrons can be rationalized within the Zaanen-Sawatzky-Allen framework. Following a brief description of the present paradigms of electronic behavior, we focus on the physics of rare-earth nickelates as an archetype of complexity emerging within the charge transfer regime. The intriguing prospect of realizing the physics of high- Tc cuprates through heterostructuring resulted in a massive endeavor to epitaxially stabilize these materials in ultrathin form. A plethora of new phenomena unfolded in such artificial structures due to the effect of epitaxial strain, quantum confinement, and interfacial charge transfer. Here we review themore » present status of artificial rare-earth nickelates in an effort to uncover the interconnection between the electronic and magnetic behavior and the underlying crystal structure. Here, we conclude by discussing future directions to disentangle the puzzle regarding the origin of the metal-insulator transition, the role of oxygen holes, and the true nature of the antiferromagnetic spin configuration in the ultrathin limit.« less

The effects of maternal working conditions and mastery on child behavior problems: studying the intergenerational transmission of social control.

PubMed

Rogers, S J; Parcel, T L; Menaghan, E G

1991-06-01

We assess the impact of maternal sense of mastery and maternal working conditions on maternal perceptions of children's behavior problems as a means to study the transmission of social control across generations. We use a sample of 521 employed mothers and their four-to six-year-old children from the National Longitudinal Survey's Youth Cohort in 1986. Regarding working conditions, we consider mother's hourly wage, work hours, and job content including involvement with things (vs. people), the requisite level of physical activity, and occupational complexity. We also consider maternal and child background and current family characteristics, including marital status, family size, and home environment. Maternal mastery was related to fewer reported behavior problems among children. Lower involvement with people and higher involvement with things, as well as low physical activity, were related significantly to higher levels of perceived problems. In addition, recent changes in maternal marital status, including maternal marriage or remarriage, increased reports of problems; stronger home environments had the opposite effect. We interpret these findings as suggesting how maternal experiences of control in the workplace and personal resources of control can influence the internalization of control in children.

Non-Fermi liquids in oxide heterostructures

NASA Astrophysics Data System (ADS)

Stemmer, Susanne; Allen, S. James

2018-06-01

Understanding the anomalous transport properties of strongly correlated materials is one of the most formidable challenges in condensed matter physics. For example, one encounters metal-insulator transitions, deviations from Landau Fermi liquid behavior, longitudinal and Hall scattering rate separation, a pseudogap phase, and bad metal behavior. These properties have been studied extensively in bulk materials, such as the unconventional superconductors and heavy fermion systems. Oxide heterostructures have recently emerged as new platforms to probe, control, and understand strong correlation phenomena. This article focuses on unconventional transport phenomena in oxide thin film systems. We use specific systems as examples, namely charge carriers in SrTiO3 layers and interfaces with SrTiO3, and strained rare earth nickelate thin films. While doped SrTiO3 layers appear to be a well behaved, though complex, electron gas or Fermi liquid, the rare earth nickelates are a highly correlated electron system that may be classified as a non-Fermi liquid. We discuss insights into the underlying physics that can be gained from studying the emergence of non-Fermi liquid behavior as a function of the heterostructure parameters. We also discuss the role of lattice symmetry and disorder in phenomena such as metal-insulator transitions in strongly correlated heterostructures.

Prosthetic Avian Vocal Organ Controlled by a Freely Behaving Bird Based on a Low Dimensional Model of the Biomechanical Periphery

PubMed Central

Arneodo, Ezequiel M.; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B.

2012-01-01

Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform. PMID:22761555

Dynamic behavior of the weld pool in stationary GMAW

NASA Astrophysics Data System (ADS)

Chapuis, J.; Romero, E.; Bordreuil, C.; Soulié, F.; Fras, G.

2010-06-01

Because hump formation limits welding productivity, better understanding of the humping phenomena during the welding process is needed to access to process modifications that decrease the tendency for hump formation and then allow higher productivity welding. From a physical point of view, the mechanism identified is the Rayleigh instability initiated by strong surface tension gradient which induces a variation of kinetic flow. But the causes of the appearance of this instability are not yet well explained. Because of the phenomena complex and multi-physics, we chose in first step to conduct an analysis of the characteristic times involved in weld pool in pulsed stationary GMAW. The goal is to study the dynamic behavior of the weld pool, using our experimental multi physics approach. The experimental tool and methodology developed to understand these fast phenomena are presented first: frames acquisition with high speed digital camera and specific optical devices, numerical library. The analysis of geometric parameters of the weld pool during welding operation are presented in the last part: we observe the variations of wetting angles (or contact lines angles), the base and the height of the weld pool (macro-drop) versus weld time.

Phase transitions in models of human cooperation

NASA Astrophysics Data System (ADS)

Perc, Matjaž

2016-08-01

If only the fittest survive, why should one cooperate? Why should one sacrifice personal benefits for the common good? Recent research indicates that a comprehensive answer to such questions requires that we look beyond the individual and focus on the collective behavior that emerges as a result of the interactions among individuals, groups, and societies. Although undoubtedly driven also by culture and cognition, human cooperation is just as well an emergent, collective phenomenon in a complex system. Nonequilibrium statistical physics, in particular the collective behavior of interacting particles near phase transitions, has already been recognized as very valuable for understanding counterintuitive evolutionary outcomes. However, unlike pairwise interactions among particles that typically govern solid-state physics systems, interactions among humans often involve group interactions, and they also involve a larger number of possible states even for the most simplified description of reality. Here we briefly review research done in the realm of the public goods game, and we outline future research directions with an emphasis on merging the most recent advances in the social sciences with methods of nonequilibrium statistical physics. By having a firm theoretical grip on human cooperation, we can hope to engineer better social systems and develop more efficient policies for a sustainable and better future.

Break for Physical Activity: Incorporating Classroom-Based Physical Activity Breaks into Preschools

ERIC Educational Resources Information Center

Wadsworth, Danielle D.; Robinson, Leah E.; Beckham, Karen; Webster, Kip

2012-01-01

Engaging in moderate-to-vigorous physical activity is essential to lifelong health and wellness. Physical activity behaviors established in early childhood relate to physical activity behaviors in later years. However, research has shown that children are adopting more sedentary behaviors. Incorporating structured and planned physical activity…

Emergence of Life-Like Properties from Dissipative Self-Assembly of Nanoparticles

NASA Astrophysics Data System (ADS)

Ilday, Serim; Makey, Ghaith; Akguc, Gursoy B.; Yavuz, Ozgun; Tokel, Onur; Pavlov, Ihor; Gulseren, Oguz; Ilday, F. Omer

A profoundly fundamental question at the interface between physics and biology remains open: What are the minimum requirements for emergence of life-like properties from non-living systems? Here, we address this question and report emergent complex behavior of tens to thousands of colloidal nanoparticles in a system designed to be as plain as possible: The system is driven far from equilibrium by ultrafast laser pulses, which create spatiotemporal temperature gradients, inducing Marangoni-type flow that drags the particles towards aggregation; strong Brownian motion, used as source of fluctuations, opposes aggregation. Nonlinear feedback mechanisms naturally arise between the flow, the aggregate, and Brownian motion, allowing fast external control with minimal intervention. Consequently, complex behavior, analogous to those commonly seen in living organisms, emerges, whereby the aggregates can self-sustain, self-regulate, self-replicate, self-heal and can be transferred from one location to another, all within seconds. Aggregates can comprise of only one pattern or bifurcated patterns can co-exist, compete, survive or die.

Protecting workers in the home care industry: workers' experienced job demands, resource gaps, and benefits following a socially supportive intervention.

PubMed

Mabry, Linda; Parker, Kelsey N; Thompson, Sharon V; Bettencourt, Katrina M; Haque, Afsara; Luther Rhoten, Kristy; Wright, Rob R; Hess, Jennifer A; Olson, Ryan

2018-05-02

The Community of Practice and Safety Support (COMPASS) program is a peer-led group intervention for home care workers. In a randomized controlled trial, COMPASS significantly improved workers' professional support networks and safety and health behaviors. However, quantitative findings failed to capture workers' complex emotional, physical, and social experiences with job demands, resource limitations, and the intervention itself. Therefore, we conducted qualitative follow-up interviews with a sample of participants (n = 28) in the program. Results provided examples of unique physical and psychological demands, revealed stressful resource limitations (e.g., safety equipment access), and elucidated COMPASS's role as a valuable resource.

Individualized Levels System and Systematic Stimulus Pairing to Reduce Multiply Controlled Aggression of a Child With Autism Spectrum Disorder.

PubMed

Randall, Kayla R; Lambert, Joseph M; Matthews, Mary P; Houchins-Juarez, Nealetta J

2018-05-01

Research has shown that physical aggression is common in individuals with autism spectrum disorder (ASD). Interventions for multiply controlled aggression may be complex and difficult to implement with fidelity. As a result, the probability of treatment efficacy for this class of behavior may suffer. We designed an individualized levels system to reduce the physical aggression of an 11-year-old female with ASD. We then employed a systematic stimulus pairing procedure to facilitate generalization. Results suggest individualized levels systems can suppress multiply controlled aggression and that systematic stimulus pairing is an effective way to transfer treatment effects from trained therapists to caregivers.

Threshold behaviors of social dynamics and financial outcomes of Ponzi scheme diffusion in complex networks

NASA Astrophysics Data System (ADS)

Fu, Peihua; Zhu, Anding; Ni, He; Zhao, Xin; Li, Xiulin

2018-01-01

Ponzi schemes always lead to mass disasters after collapse. It is important to study the critical behaviors of both social dynamics and financial outcomes for Ponzi scheme diffusion in complex networks. We develop the potential-investor-divestor-investor (PIDI) model by considering the individual behavior of direct reinvestment. We find that only the spreading rate relates to the epidemic outbreak while the reinvestment rate relates to the zero and non-zero final states for social dynamics of both homo- and inhomogeneous networks. Financially, we find that there is a critical spreading threshold, above which the scheme needs not to use its own initial capital for taking off, i.e. the starting cost is covered by the rapidly inflowing funds. However, the higher the cost per recruit, the larger the critical spreading threshold and the worse the financial outcomes. Theoretical and simulation results also reveal that schemes are easier to take off in inhomogeneous networks. The reinvestment rate does not affect the starting. However, it improves the financial outcome in the early stages and postpones the outbreak of financial collapse. Some policy suggestions for the regulator from the perspective of social physics are proposed in the end of the paper.

Pharmacological action of Panax ginseng on the behavioral toxicities induced by psychotropic agents.

PubMed

Kim, Hyoung-Chun; Shin, Eun-Joo; Jang, Choon-Gon; Lee, Myung-Koo; Eun, Jae-Soon; Hong, Jin-Tae; Oh, Ki-Wan

2005-09-01

Morphine-induced analgesia has been shown to be antagonized by ginseng total saponins (GTS), which also inhibit the development of analgesic tolerance to and physical dependence on morphine. GTS is involved in both of these processes by inhibiting morphine-6-dehydrogenase, which catalyzes the synthesis of morphinone from morphine, and by increasing the level of hepatic glutathione, which participates in the toxicity response. Thus, the dual actions of ginseng are associated with the detoxification of morphine. In addition, the inhibitory or facilitated effects of GTS on electrically evoked contractions in guinea pig ileum (mu-receptors) and mouse vas deferens (delta-receptors) are not mediated through opioid receptors, suggesting the involvement of non-opioid mechanisms. GTS also attenuates hyperactivity, reverse tolerance (behavioral sensitization), and conditioned place preference induced by psychotropic agents, such as methamphetamine, cocaine, and morphine. These effects of GTS may be attributed to complex pharmacological actions between dopamine receptors and a serotonergic/adenosine A2A/ delta-opioid receptor complex. Ginsenosides also attenuate the morphine-induced cAMP signaling pathway. Together, the results suggest that GTS may be useful in the prevention and therapy of the behavioral side effects induced by psychotropic agents.

Nonlinear analysis of dynamic signature

NASA Astrophysics Data System (ADS)

Rashidi, S.; Fallah, A.; Towhidkhah, F.

2013-12-01

Signature is a long trained motor skill resulting in well combination of segments like strokes and loops. It is a physical manifestation of complex motor processes. The problem, generally stated, is that how relative simplicity in behavior emerges from considerable complexity of perception-action system that produces behavior within an infinitely variable biomechanical and environmental context. To solve this problem, we present evidences which indicate that motor control dynamic in signing process is a chaotic process. This chaotic dynamic may explain a richer array of time series behavior in motor skill of signature. Nonlinear analysis is a powerful approach and suitable tool which seeks for characterizing dynamical systems through concepts such as fractal dimension and Lyapunov exponent. As a result, they can be analyzed in both horizontal and vertical for time series of position and velocity. We observed from the results that noninteger values for the correlation dimension indicates low dimensional deterministic dynamics. This result could be confirmed by using surrogate data tests. We have also used time series to calculate the largest Lyapunov exponent and obtain a positive value. These results constitute significant evidence that signature data are outcome of chaos in a nonlinear dynamical system of motor control.

Choices Matter, but How Do We Model Them?

NASA Astrophysics Data System (ADS)

Brelsford, C.; Dumas, M.

2017-12-01

Quantifying interactions between social systems and the physical environment we live within has long been a major scientific challenge. Humans have had such a large influence on our environment that it is no longer reasonable to consider the behavior of an ecological or hydrological system from a purely `physical' perspective: imagining a system that excludes the influence of human choices and behavior. Understanding the role that human social choices play in the energy water nexus is crucial for developing accurate models in that space. The relatively new field of socio-hydrology is making progress towards understanding the role humans play in hydrological systems. While this fact is now widely recognized across the many academic fields that study water systems, we have yet to develop a coherent set of theories for how to model the behavior of these complex and highly interdependent socio-hydrological systems. How should we conceptualize hydrological systems as socio-ecological systems (i.e. system with variables, states, parameters, actors who can control certain variables and a sense of the desirability of states) within which the rigorous study of feedbacks becomes possible? This talk reviews the state of knowledge of how social decisions around water consumption, allocation, and transport influence and are influenced by the physical hydrology that water also moves within. We cover recent papers in socio-hydrology, engineering, water law, and institutional analysis. There have been several calls within socio-hydrology to model human social behavior endogenously along with the hydrology. These improvements are needed across a range of spatial and temporal scales. We suggest two potential strategies for coupled models that allow endogenous water consumption behavior: a social first model which looks for empirical relationships between water consumption and allocation choices and the hydrological state, and a hydrology first model in which we look for regularities in how water regimes influence behavior, regional economies, or allocation institutions.

A Lamellar Complex of Lecithin and Poly-l-Tyrosine

PubMed Central

Giannoni, G.; Padden, F. J.; Roe, R. J.

1971-01-01

Complexes of poly-L-tyrosine (PT) with dipalmitoyllecithin, synthetic, (DPL) and with egg lecithin (EL) have been obtained by precipitation from methanol-water solutions. Chemical analysis indicates that both lecithins bind PT up to a limiting ratio of about 4 tyrosine residues/lecithin molecule. DPL-PT complexes have a lamellar structure closely resembling lecithin itself. In fact, DPL and DPL-PT lamellae have very nearly the same thickness as precipitated from methanol-water, although their swelling behavior on resuspension in pure water is different. The complexes crystallize in the form of hexagonal platelets, some monolayers and some with terraced spiral growths, with a thickness of 50-55 A. In X-ray and electron diffraction they yield sharp reflections at 4.14 A which are characteristic of hexagonal packing of phospholipid paraffinic chains. The order-disorder transition temperature of this crystalline lattice, determined by differential scanning calorimetry, is somewhat higher in the complex than in pure DPL. Physical models consistent with these observations are discussed. ImagesFIGURE 1 aFIGURE 1 b PMID:5134208

Calculation of load-bearing capacity of prestressed reinforced concrete trusses by the finite element method

NASA Astrophysics Data System (ADS)

Agapov, Vladimir; Golovanov, Roman; Aidemirov, Kurban

2017-10-01

The technique of calculation of prestressed reinforced concrete trusses with taking into account geometrical and physical nonlinearity is considered. As a tool for solving the problem, the finite element method has been chosen. Basic design equations and methods for their solution are given. It is assumed that there are both a prestressed and nonprestressed reinforcement in the bars of the trusses. The prestress is modeled by setting the temperature effect on the reinforcement. The ways of taking into account the physical and geometrical nonlinearity for bars of reinforced concrete trusses are considered. An example of the analysis of a flat truss is given and the behavior of the truss on various stages of its loading up to destruction is analyzed. A program for the analysis of flat and spatial concrete trusses taking into account the nonlinear deformation is developed. The program is adapted to the computational complex PRINS. As a part of this complex it is available to a wide range of engineering, scientific and technical workers

Considerations for the Use of Remote Gaze Tracking to Assess Behavior in Flight Simulators

NASA Technical Reports Server (NTRS)

Kalar, Donald J.; Liston, Dorion; Mulligan, Jeffrey B.; Beutter, Brent; Feary, Michael

2016-01-01

Complex user interfaces (such as those found in an aircraft cockpit) may be designed from first principles, but inevitably must be evaluated with real users. User gaze data can provide valuable information that can help to interpret other actions that change the state of the system. However, care must be taken to ensure that any conclusions drawn from gaze data are well supported. Through a combination of empirical and simulated data, we identify several considerations and potential pitfalls when measuring gaze behavior in high-fidelity simulators. We show that physical layout, behavioral differences, and noise levels can all substantially alter the quality of fit for algorithms that segment gaze measurements into individual fixations. We provide guidelines to help investigators ensure that conclusions drawn from gaze tracking data are not artifactual consequences of data quality or analysis techniques.

USSR and Eastern Europe Scientific Abstracts Biomedical and Behavioral Sciences No. 71.

DTIC Science & Technology

1977-05-20

the lowcapacity method . Physical properties of the insecticide liquid used must be determined in order to adjust the spray setting, and to assure...supply and hinder broad use of the method . No references. USSR UDC 632.913.1 METHYL BROMIDE USED TO DESTROY THE POTATO BUG Moscow ZASHCHITA RASTENIY...different amino acids, 13 to 15 trace elements, and vitamin B complex, when prepared by a method involving separation of the alcohol by heating

Phase-Space Approach to the Tunnel Effect: A New Semiclassical Traversal Time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xavier, A.L. Jr.; de Aguiar, M.A.

1997-11-01

We determine the semiclassical coherent-state propagator for a particle going through one-dimensional evolution in a simple barrier potential. The described semiclassical method makes use of complex trajectories which, by its turn, enables the definition of (real) traversal times in the complexified phase space. We then discuss the behavior of this time for a wave packet whose average energy is below the barrier height. {copyright} {ital 1997} {ital The American Physical Society}

Bidirectional associations between activity-related parenting practices, and child physical activity, sedentary screen-based behavior and body mass index: a longitudinal analysis.

PubMed

Sleddens, Ester F C; Gubbels, Jessica S; Kremers, Stef P J; van der Plas, Eline; Thijs, Carel

2017-07-06

It has been generally assumed that activity-related parenting practices influence children's activity behavior and weight status. However, vice versa parents may also change their parenting behaviors in response to their perceptions of their child's activity behavior and weight status. This study examined the bidirectional relationships between activity-related parenting practices, and physical activity, sedentary screen-based behavior, and body mass index (BMI) between children's age of 5 and 7 years. Three scales of the Activity-related Parenting Questionnaire (i.e. 'restriction of sedentary behavior', 'stimulation of physical activity', and 'monitoring of physical activity') were completed by 1694 parents of the Dutch KOALA Birth Cohort Study at the child's age of around 5 and again around age 7. Physical activity, sedentary screen-based behavior and BMI were measured at both ages as well. Linear regression models were used to estimate the bidirectional associations between each parenting practice and the child's physical activity levels, sedentary screen-based behavior and BMI z-scores. Several parenting practices at age 5 predicted child physical activity, sedentary screen-based behavior, and BMI z-scores at age 7. Restriction of sedentary behavior positively predicted child BMI and sedentary screen-based behavior, whereas this practice negatively predicted child physical activity. In addition, stimulation of physical activity at age 5 was significantly associated with higher levels of child physical activity at age 7. The following child factors at age 5 predicted parenting practices at age 7: Child physical activity positively predicted parental stimulation of physical activity and monitoring activities. Sedentary screen-based behavior was associated with lower parental stimulation to be active. Findings generally revealed that parents and children mutually influence each other's behavior. A reinforcing feedback loop was present between parental stimulation of physical activity and child physical activity. Bidirectional parent-child interaction should be considered in future research in order to properly inform parenting-related intervention programs aimed at preventing or treating childhood overweight or obesity. System dynamic methods to explore the existence of reinforcing or balancing loops are needed in this regard.

Operant conditioning: a minimal components requirement in artificial spiking neurons designed for bio-inspired robot's controller

PubMed Central

Cyr, André; Boukadoum, Mounir; Thériault, Frédéric

2014-01-01

In this paper, we investigate the operant conditioning (OC) learning process within a bio-inspired paradigm, using artificial spiking neural networks (ASNN) to act as robot brain controllers. In biological agents, OC results in behavioral changes learned from the consequences of previous actions, based on progressive prediction adjustment from rewarding or punishing signals. In a neurorobotics context, virtual and physical autonomous robots may benefit from a similar learning skill when facing unknown and unsupervised environments. In this work, we demonstrate that a simple invariant micro-circuit can sustain OC in multiple learning scenarios. The motivation for this new OC implementation model stems from the relatively complex alternatives that have been described in the computational literature and recent advances in neurobiology. Our elementary kernel includes only a few crucial neurons, synaptic links and originally from the integration of habituation and spike-timing dependent plasticity as learning rules. Using several tasks of incremental complexity, our results show that a minimal neural component set is sufficient to realize many OC procedures. Hence, with the proposed OC module, designing learning tasks with an ASNN and a bio-inspired robot context leads to simpler neural architectures for achieving complex behaviors. PMID:25120464

Operant conditioning: a minimal components requirement in artificial spiking neurons designed for bio-inspired robot's controller.

PubMed

Cyr, André; Boukadoum, Mounir; Thériault, Frédéric

2014-01-01

In this paper, we investigate the operant conditioning (OC) learning process within a bio-inspired paradigm, using artificial spiking neural networks (ASNN) to act as robot brain controllers. In biological agents, OC results in behavioral changes learned from the consequences of previous actions, based on progressive prediction adjustment from rewarding or punishing signals. In a neurorobotics context, virtual and physical autonomous robots may benefit from a similar learning skill when facing unknown and unsupervised environments. In this work, we demonstrate that a simple invariant micro-circuit can sustain OC in multiple learning scenarios. The motivation for this new OC implementation model stems from the relatively complex alternatives that have been described in the computational literature and recent advances in neurobiology. Our elementary kernel includes only a few crucial neurons, synaptic links and originally from the integration of habituation and spike-timing dependent plasticity as learning rules. Using several tasks of incremental complexity, our results show that a minimal neural component set is sufficient to realize many OC procedures. Hence, with the proposed OC module, designing learning tasks with an ASNN and a bio-inspired robot context leads to simpler neural architectures for achieving complex behaviors.

Cyber-Physical System Security of Smart Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagle, Jeffery E.

2012-01-31

Abstract—This panel presentation will provide perspectives of cyber-physical system security of smart grids. As smart grid technologies are deployed, the interconnected nature of these systems is becoming more prevalent and more complex, and the cyber component of this cyber-physical system is increasing in importance. Studying system behavior in the face of failures (e.g., cyber attacks) allows a characterization of the systems’ response to failure scenarios, loss of communications, and other changes in system environment (such as the need for emergent updates and rapid reconfiguration). The impact of such failures on the availability of the system can be assessed and mitigationmore » strategies considered. Scenarios associated with confidentiality, integrity, and availability are considered. The cyber security implications associated with the American Recovery and Reinvestment Act of 2009 in the United States are discussed.« less

Electronic Interfacial Effects in Epitaxial Heterostructures based on LaMnO3.

NASA Astrophysics Data System (ADS)

Christen, Hans M.; Varela, M.; Lee, H. N.; Kim, D. H.; Chisholm, M. F.; Cantoni, C.; Petit, L.; Schulthess, T. C.; Lowndes, D. H.

2006-03-01

Studies of chemically abrupt interfaces provide an ideal platform to study the effects of discontinuities and asymmetries of the electronic configuration on the transport and magnetic properties of complex oxides. In addition, the behavior of complex materials near interfaces plays the most crucial role not only in devices and nanostructures but also in complex structures in the form of composites and superlattices, including artificial multiferroics. Interfaces in the ABO3 perovskite system are particularly attractive because structurally similar oxides with fundamentally different physical properties can be integrated epitaxially. To explore the electronic effects at interfaces and to probe the physical properties that result from local electronic changes, we have synthesized structures containing LaMnO3 and insulating perovskites using pulsed laser deposition. The local electron energy loss spectroscopy (EELS) capability of a scanning transmission electron microscope (STEM) is used to probe the electronic configuration in the LaMnO3 films as a function of the distance from the interfaces. The results are compared to macroscopic measurements and theoretical predictions. Research sponsored by the U.S. Department of Energy under contract DE-AC05-00OR22725 with the Oak Ridge National Laboratory, managed by UT-Battelle, LLC.

Relations between sedentary behavior and FITNESSGRAM healthy fitness zone achievement and physical activity.

PubMed

Tucker, Jacob S; Martin, Scott; Jackson, Allen W; Morrow, James R; Greenleaf, Christy A; Petrie, Trent A

2014-07-01

To investigate the relations between sedentary behaviors and health-related physical fitness and physical activity in middle school boys and girls. Students (n = 1515) in grades 6-8 completed the Youth Risk Behavior Survey sedentary behavior questions, the FITNESSGRAM physical fitness items, and FITNESSGRAM physical activity self-report questions. When students reported ≤ 2 hours per day of sedentary behaviors, their odds of achieving the FITNESSGRAM Healthy Fitness Zone for aerobic capacity, muscular strength and endurance, flexibility, and body composition increased. Similarly, the odds of achieving physical activity guidelines for children increased when students reported ≤ 2 hours per day of sedentary behaviors. Results illustrate the importance of keeping sedentary behaviors to ≤ 2 hours per day in middle school children, thus increasing the odds that the student will achieve sufficient health-related fitness benefits and be more likely to achieve the national physical activity guidelines.

The relation between bystanders’ behavioral reactivity to distress and later helping behavior during a violent conflict in virtual reality

PubMed Central

Neyret, Solène; Slater, Mel; de Gelder, Beatrice

2018-01-01

The occurrence of helping behavior is thought to be automatically triggered by reflexive reactions and promoted by intuitive decisions. Here, we studied whether reflexive reactions to an emergency situation are associated with later helping behavior in a different situation, a violent conflict. First, 29 male supporters of F.C. Barcelona performed a cued-reaction time task with a low and high cognitive load manipulation, to tap into reflexive and reflective processes respectively, during the observation of an emergency. Next, participants entered a bar in Virtual Reality and had a conversation with a virtual fellow supporter. During this conversation, a virtual Real Madrid supporter entered and started an aggressive argument with the fellow supporter that escalated into a physical fight. Verbal and physical interventions of the participant served as measures of helping behavior. Results showed that faster responses to an emergency situation during low, but not during high cognitive load, were associated with more interventions during the violent conflict. However, a tendency to describe the decision to act during the violent conflict as intuitive and reflex-like was related to more interventions. Further analyses revealed that a disposition to experience sympathy, other-oriented feelings during distressful situations, was related to self-reported intuitive decision-making, a reduced distance to the perpetrator, and higher in the intervening participants. Taken together, these results shed new light on helping behavior and are consistent with the notion of a motivational system in which the act of helping is dependent on a complex interplay between intuitive, reflexive and deliberate, reflective processes. PMID:29672638

The relation between bystanders' behavioral reactivity to distress and later helping behavior during a violent conflict in virtual reality.

PubMed

Hortensius, Ruud; Neyret, Solène; Slater, Mel; de Gelder, Beatrice

2018-01-01

The occurrence of helping behavior is thought to be automatically triggered by reflexive reactions and promoted by intuitive decisions. Here, we studied whether reflexive reactions to an emergency situation are associated with later helping behavior in a different situation, a violent conflict. First, 29 male supporters of F.C. Barcelona performed a cued-reaction time task with a low and high cognitive load manipulation, to tap into reflexive and reflective processes respectively, during the observation of an emergency. Next, participants entered a bar in Virtual Reality and had a conversation with a virtual fellow supporter. During this conversation, a virtual Real Madrid supporter entered and started an aggressive argument with the fellow supporter that escalated into a physical fight. Verbal and physical interventions of the participant served as measures of helping behavior. Results showed that faster responses to an emergency situation during low, but not during high cognitive load, were associated with more interventions during the violent conflict. However, a tendency to describe the decision to act during the violent conflict as intuitive and reflex-like was related to more interventions. Further analyses revealed that a disposition to experience sympathy, other-oriented feelings during distressful situations, was related to self-reported intuitive decision-making, a reduced distance to the perpetrator, and higher in the intervening participants. Taken together, these results shed new light on helping behavior and are consistent with the notion of a motivational system in which the act of helping is dependent on a complex interplay between intuitive, reflexive and deliberate, reflective processes.

Characterizing Pedagogical Practices of University Physics Students in Informal Learning Environments

NASA Astrophysics Data System (ADS)

Hinko, Kathleen

2016-03-01

University educators (UEs) have a long history of teaching physics not only in formal classroom settings but also in informal outreach environments. The pedagogical practices of UEs in informal physics teaching have not been widely studied, and they may provide insight into formal practices and preparation. We investigate the interactions between UEs and children in an afterschool physics program facilitated by university physics students from the University of Colorado Boulder. In this program, physics undergraduates, graduate students and post-doctoral researchers work with K-8 children on hands-on physics activities on a weekly basis over the course of a semester. We use an Activity Theoretic framework as a tool to examine situational aspects of individuals' behavior in the complex structure of the afterschool program. Using this framework, we analyze video of UE-child interactions and identify three main pedagogical modalities that UEs display during activities: Instruction, Consultation and Participation modes. These modes are characterized by certain language, physical location, and objectives that establish differences in UE-child roles and division of labor. Based on this analysis, we discuss implications for promoting pedagogical strategies through purposeful curriculum development and university educator preparation.

Psychological, interpersonal, and clinical factors predicting time spent on physical activity among Mexican patients with hypertension.

PubMed

Ybarra Sagarduy, José Luis; Camacho Mata, Dacia Yurima; Moral de la Rubia, José; Piña López, Julio Alfonso; Yunes Zárraga, José Luis Masud

2018-01-01

It is widely known that physical activity is the key to the optimal management and clinical control of hypertension. This research was conducted to identify factors that can predict the time spent on physical activity among Mexican adults with hypertension. This cross-sectional study was conducted among 182 Mexican patients with hypertension, who completed a set of self-administered questionnaires related to personality, social support, and medical adherence and health care behaviors, body mass index, and time since the disease diagnosis. Several path analyses were performed in order to test the predictors of the study behavior. Lower tolerance to frustration, more tolerance to ambiguity, more effective social support, and less time since the disease diagnosis predicted more time spent on physical activity, accounting for 13.3% of the total variance. The final model shows a good fit to the sample data ( p BS =0.235, χ 2 / gl =1.519, Jöreskog and Sörbom's Goodness of Fit Index =0.987, adjusted modality =0.962, Bollen's Incremental Fit Index =0.981, Bentler-Bonett Normed Fit Index =0.946, standardized root mean square residual =0.053). The performance of physical activity in patients with hypertension depends on a complex set of interactions between personal, interpersonal, and clinical variables. Understanding how these factors interact might enhance the design of interdisciplinary intervention programs so that quality of life of patients with hypertension improves and they might be able to manage and control their disease well.

Network dynamics and systems biology

NASA Astrophysics Data System (ADS)

Norrell, Johannes A.

The physics of complex systems has grown considerably as a field in recent decades, largely due to improved computational technology and increased availability of systems level data. One area in which physics is of growing relevance is molecular biology. A new field, systems biology, investigates features of biological systems as a whole, a strategy of particular importance for understanding emergent properties that result from a complex network of interactions. Due to the complicated nature of the systems under study, the physics of complex systems has a significant role to play in elucidating the collective behavior. In this dissertation, we explore three problems in the physics of complex systems, motivated in part by systems biology. The first of these concerns the applicability of Boolean models as an approximation of continuous systems. Studies of gene regulatory networks have employed both continuous and Boolean models to analyze the system dynamics, and the two have been found produce similar results in the cases analyzed. We ask whether or not Boolean models can generically reproduce the qualitative attractor dynamics of networks of continuously valued elements. Using a combination of analytical techniques and numerical simulations, we find that continuous networks exhibit two effects---an asymmetry between on and off states, and a decaying memory of events in each element's inputs---that are absent from synchronously updated Boolean models. We show that in simple loops these effects produce exactly the attractors that one would predict with an analysis of the stability of Boolean attractors, but in slightly more complicated topologies, they can destabilize solutions that are stable in the Boolean approximation, and can stabilize new attractors. Second, we investigate ensembles of large, random networks. Of particular interest is the transition between ordered and disordered dynamics, which is well characterized in Boolean systems. Networks at the transition point, called critical, exhibit many of the features of regulatory networks, and recent studies suggest that some specific regulatory networks are indeed near-critical. We ask whether certain statistical measures of the ensemble behavior of large continuous networks are reproduced by Boolean models. We find that, in spite of the lack of correspondence between attractors observed in smaller systems, the statistical characterization given by the continuous and Boolean models show close agreement, and the transition between order and disorder known in Boolean systems can occur in continuous systems as well. One effect that is not present in Boolean systems, the failure of information to propagate down chains of elements of arbitrary length, is present in a class of continuous networks. In these systems, a modified Boolean theory that takes into account the collective effect of propagation failure on chains throughout the network gives a good description of the observed behavior. We find that propagation failure pushes the system toward greater order, resulting in a partial or complete suppression of the disordered phase. Finally, we explore a dynamical process of direct biological relevance: asymmetric cell division in A. thaliana. The long term goal is to develop a model for the process that accurately accounts for both wild type and mutant behavior. To contribute to this endeavor, we use confocal microscopy to image roots in a SHORT-ROOT inducible mutant. We compute correlation functions between the locations of asymmetrically divided cells, and we construct stochastic models based on a few simple assumptions that accurately predict the non-zero correlations. Our result shows that intracellular processes alone cannot be responsible for the observed divisions, and that an intercell signaling mechanism could account for the measured correlations.

On the amphibious food uptake and prey manipulation behavior in the Balkan-Anatolian crested newt (Triturus ivanbureschi, Arntzen and Wielstra, 2013).

PubMed

Lukanov, Simeon; Tzankov, Nikolay; Handschuh, Stephan; Heiss, Egon; Naumov, Borislav; Natchev, Nikolay

2016-06-01

Feeding behavior in salamanders undergoing seasonal habitat shifts poses substantial challenges caused by differences in the physical properties of air and water. Adapting to these specific environments, urodelans use suction feeding predominantly under water as opposed to lingual food prehension on land. This study aims to determine the functionality of aquatic and terrestrial feeding behavior in the Balkan-Anatolian crested newt (Triturus ivanbureschi) in its terrestrial stage. During the terrestrial stage, these newts feed frequently in water where they use hydrodynamic mechanisms for prey capture. On land, prey apprehension is accomplished mainly by lingual prehension, while jaw prehension seems to be the exception (16.67%) in all terrestrial prey capture events. In jaw prehension events there was no detectable depression of the hyo-lingual complex. The success of terrestrial prey capture was significantly higher when T. ivanbureschi used lingual prehension. In addition to prey capture, we studied the mechanisms involved in the subduction of prey. In both media, the newts frequently used a shaking behavior to immobilize the captured earthworms. Apparently, prey shaking constitutes a significant element in the feeding behavior of T. ivanbureschi. Prey immobilization was applied more frequently during underwater feeding, which necessitates a discussion of the influence of the feeding media on food manipulation. We also investigated the osteology of the cranio-cervical complex in T. ivanbureschi to compare it to that of the predominantly terrestrial salamandrid Salamandra salamandra. Copyright © 2016 Elsevier GmbH. All rights reserved.

Unraveling complex nonlinear elastic behaviors in rocks using dynamic acousto-elasticity

NASA Astrophysics Data System (ADS)

Riviere, J.; Guyer, R.; Renaud, G.; TenCate, J. A.; Johnson, P. A.

2012-12-01

In comparison with standard nonlinear ultrasonic methods like frequency mixing or resonance based measurements that allow one to extract average, bulk variations of modulus and attenuation versus strain level, dynamic acousto-elasticity (DAE) allows to obtain the elastic behavior over the entire dynamic cycle, detailing the full nonlinear behavior under tension and compression, including hysteresis and memory effects. This method consists of exciting a sample in Bulk-mode resonance at strains of 10-7 to 10-5 and simultaneously probing with a sequence of high frequency, low amplitude pulses. Time of flight and amplitudes of these pulses, respectively related to nonlinear elastic and dissipative parameters, can be plotted versus vibration strain level. Despite complex nonlinear signatures obtained for most rocks, it can be shown that for low strain amplitude (< 10-6), the nonlinear classical theory issued from a Taylor decomposition can explain the harmonic content. For higher strain, harmonic content becomes richer and the material exhibits more hysteretic behaviors, i.e. strain rate dependencies. Such observations have been made in the past (e.g., Pasqualini et al., JGR 2007), but not with the extreme detail of elasticity provided by DAE. Previous quasi-static measurements made in Berea sandstone (Claytor et al, GRL 2009), show that the hysteretic behavior disappears when the protocol is performed at a very low strain-rate (static limit). Therefore, future work will aim at linking quasi-static and dynamic observations, i.e. the frequency or strain-rate dependence, in order to understand underlying physical phenomena.

An ensemble Kalman filter for statistical estimation of physics constrained nonlinear regression models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harlim, John, E-mail: jharlim@psu.edu; Mahdi, Adam, E-mail: amahdi@ncsu.edu; Majda, Andrew J., E-mail: jonjon@cims.nyu.edu

2014-01-15

A central issue in contemporary science is the development of nonlinear data driven statistical–dynamical models for time series of noisy partial observations from nature or a complex model. It has been established recently that ad-hoc quadratic multi-level regression models can have finite-time blow-up of statistical solutions and/or pathological behavior of their invariant measure. Recently, a new class of physics constrained nonlinear regression models were developed to ameliorate this pathological behavior. Here a new finite ensemble Kalman filtering algorithm is developed for estimating the state, the linear and nonlinear model coefficients, the model and the observation noise covariances from available partialmore » noisy observations of the state. Several stringent tests and applications of the method are developed here. In the most complex application, the perfect model has 57 degrees of freedom involving a zonal (east–west) jet, two topographic Rossby waves, and 54 nonlinearly interacting Rossby waves; the perfect model has significant non-Gaussian statistics in the zonal jet with blocked and unblocked regimes and a non-Gaussian skewed distribution due to interaction with the other 56 modes. We only observe the zonal jet contaminated by noise and apply the ensemble filter algorithm for estimation. Numerically, we find that a three dimensional nonlinear stochastic model with one level of memory mimics the statistical effect of the other 56 modes on the zonal jet in an accurate fashion, including the skew non-Gaussian distribution and autocorrelation decay. On the other hand, a similar stochastic model with zero memory levels fails to capture the crucial non-Gaussian behavior of the zonal jet from the perfect 57-mode model.« less

Cyber bullying and physical bullying in adolescent suicide: the role of violent behavior and substance use.

PubMed

Litwiller, Brett J; Brausch, Amy M

2013-05-01

The impact of bullying in all forms on the mental health and safety of adolescents is of particular interest, especially in the wake of new methods of bullying that victimize youths through technology. The current study examined the relationship between victimization from both physical and cyber bullying and adolescent suicidal behavior. Violent behavior, substance use, and unsafe sexual behavior were tested as mediators between two forms of bullying, cyber and physical, and suicidal behavior. Data were taken from a large risk-behavior screening study with a sample of 4,693 public high school students (mean age = 16.11, 47 % female). The study's findings showed that both physical bullying and cyber bullying associated with substance use, violent behavior, unsafe sexual behavior, and suicidal behavior. Substance use, violent behavior, and unsafe sexual behavior also all associated with suicidal behavior. Substance use and violent behavior partially mediated the relationship between both forms of bullying and suicidal behavior. The comparable amount of variance in suicidal behavior accounted for by both cyber bullying and physical bullying underscores the important of further cyber bullying research. The direct association of each risk behavior with suicidal behavior also underscores the importance of reducing risk behaviors. Moreover, the role of violence and substance use as mediating behaviors offers an explanation of how risk behaviors can increase an adolescent's likelihood of suicidal behavior through habituation to physical pain and psychological anxiety.

Large Bore Powder Gun Qualification (U)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabern, Donald A.; Valdiviez, Robert

A Large Bore Powder Gun (LBPG) is being designed to enable experimentalists to characterize material behavior outside the capabilities of the NNSS JASPER and LANL TA-55 PF-4 guns. The combination of these three guns will create a capability to conduct impact experiments over a wide range of pressures and shock profiles. The Large Bore Powder Gun will be fielded at the Nevada National Security Site (NNSS) U1a Complex. The Complex is nearly 1000 ft below ground with dedicated drifts for testing, instrumentation, and post-shot entombment. To ensure the reliability, safety, and performance of the LBPG, a qualification plan has beenmore » established and documented here. Requirements for the LBPG have been established and documented in WE-14-TR-0065 U A, Large Bore Powder Gun Customer Requirements. The document includes the requirements for the physics experiments, the gun and confinement systems, and operations at NNSS. A detailed description of the requirements is established in that document and is referred to and quoted throughout this document. Two Gun and Confinement Systems will be fielded. The Prototype Gun will be used primarily to characterize the gun and confinement performance and be the primary platform for qualification actions. This gun will also be used to investigate and qualify target and diagnostic modifications through the life of the program (U1a.104 Drift). An identical gun, the Physics Gun, will be fielded for confirmatory and Pu experiments (U1a.102D Drift). Both guns will be qualified for operation. The Gun and Confinement System design will be qualified through analysis, inspection, and testing using the Prototype Gun for the majority of process. The Physics Gun will be qualified through inspection and a limited number of qualification tests to ensure performance and behavior equivalent to the Prototype gun. Figure 1.1 shows the partial configuration of U1a and the locations of the Prototype and Physics Gun/Confinement Systems.« less

Personalized Infrastructure: Leveraging Behavioral Strategies for Future Mobility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duvall, Andrew L

For decades, the transportation system has been built to position the personal automobile at the pinnacle of mobility options. This prominence is strongly reflected in individual and population behaviors, and supported by coevolved transportation policy, social norms, funding, and physical structures. Such has been the status quo for the living memory of the U.S. population. However, with the advent of emergent, technologically driven mobility options, the transportation system is in an era of rapid and disruptive change. No longer is transportation infrastructure an externality predominantly composed of physical elements; it is also now a personalized interface carried in the pocketsmore » of the majority of the population. Perceptions of personal mobility are evolving, in large part because of the proliferation of smartphone technology and the related Internet of Things (IoT), which will become increasingly essential within future transportation systems. With the emergence of personalized mobility infrastructure, many intervention approaches to influence transportation behavior do not adequately acknowledge the complexity of the social/digital environment within which transportation decisions are made. Transportation decisions are influenced by multiple facets, including costs and benefits in time and money, but also by sociocultural elements shaped by social norms and diffusion of ideas. Understanding of factors that lead to transportation behaviors can help to identify incentives and leverage points whereby alternative choices may be most accepted by individuals, and which, if well coordinated, may lead to improved transportation energy outcomes. How can change be initiated to shift away from the transportation status quo? Is it possible to use technologically delivered incentives to produce meaningful changes in transportation behavior? What types of incentives and at what perceived value is necessary to induce changes in behavior? As transportation agencies look toward an ever more complex mobility landscape, and with a quickly growing population, we look for answers to these questions as the core of developing strategies for the future of transportation. Using available data from emergent modes, and experiments conducted as part of an Advanced Research Projects Agency - Energy (ARPA-E) Traveler Response Architecture using Novel Signaling for Network Efficiency in Transportation (TRANSNET) project, we look at how the sharing economy and transportation mobility services have begun to radically alter transportation behavior, while operating in parallel with traditional transportation infrastructure. Emerging modes and practices are affecting car dependence and enabling multimodality. We weigh influences on travel behaviors, identify decision breakpoints where inelastic behavior becomes elastic, incentives, and societal leverage points.« less

Association between victimization by bullying and direct self injurious behavior among adolescence in Europe: a ten-country study.

PubMed

Brunstein Klomek, Anat; Snir, Avigal; Apter, Alan; Carli, Vladimir; Wasserman, Camilla; Hadlaczky, Gergö; Hoven, Christina W; Sarchiapone, Marco; Balazs, Judit; Bobes, Julio; Brunner, Romuald; Corcoran, Paul; Cosman, Doina; Haring, Christian; Kahn, Jean-Pierre; Kaess, Michael; Postuvan, Vita; Sisask, Merike; Tubiana, Alexandra; Varnik, Airi; Žiberna, Janina; Wasserman, Danuta

2016-11-01

Previous studies have examined the association between victimization by bullying and both suicide ideation and suicide attempts. The current study examined the association between victimization by bullying and direct-self-injurious behavior (D-SIB) among a large representative sample of male and female adolescents in Europe. This study is part of the Saving and Empowering Young Lives in Europe (SEYLE) study and includes 168 schools, with 11,110 students (mean age = 14.9, SD = 0.89). Students were administered a self-report survey within the classroom, in which they were asked about three types of victimization by bullying (physical, verbal and relational) as well as direct self-injurious behavior (D-SIB). Additional risk factors (symptoms of depression and anxiety, suicide ideation, suicide attempts, loneliness, alcohol consumption, drug consumption), and protective factors (parent support, peer support, pro-social behavior) were included. The three types of victimization examined were associated with D-SIB. Examination of gender as moderator of the association between victimization (relational, verbal, and physical) and D-SIB yielded no significant results. As for the risk factors, depression, but not anxiety, partially mediated the effect of relational victimization and verbal victimization on D-SIB. As for the protective factors, students with parent and peer support and those with pro-social behaviors were at significantly lower risk of engaging in D-SIB after being victimized compared to students without support/pro-social behaviors. This large-scale study has clearly demonstrated the cross-sectional association between specific types of victimization with self-injurious behavior among adolescents and what may be part of the risk and protective factors in this complex association.

An application of the Caputo-Fabrizio operator to replicator-mutator dynamics: Bifurcation, chaotic limit cycles and control

NASA Astrophysics Data System (ADS)

Doungmo Goufo, Emile Franc

2018-02-01

The physical behaviors of replicator-mutator processes found in theoretical biophysics, physical chemistry, biochemistry and population biology remain complex with unlimited expressibility. People languages, for instance, have impressively and unpredictably changed over the time in human history. This is mainly due to the collection of small changes and collaboration with other languages. In this paper, the Caputo-Fabrizio operator is applied to a replicator-mutator dynamic taking place in midsts with movement. The model is fully analyzed and solved numerically via the Crank-Nicolson scheme. Stability and convergence results are provided. A concrete application to replicator-mutator dynamics for a population with three strategies is performed with numerical simulations provided for some fixed values of the physical position of the population symbolized by r and the grid points. Physically, it happens that limit cycles appear, not only in function of the mutation parameter μ but also in function of the values given to r . The amplitudes of limit cycles also appear to be proportional to r but the stability of the system remains unaffected. However, those limit cycles instead of disappearing as expected, are immediately followed by chaotic and unpredictable behaviors certainly due to the non-singular kernel used in the model and suitable to non-linear dynamics. Hence, the appearance and disappearance of limit cycles might be controlled by the position variable r which can also apprehend chaos.

On the physical and chemical dynamics of chromatin

NASA Astrophysics Data System (ADS)

Apratim, Manjul

The research performed leading to this dissertation is an endeavor to explore two broad classes of developmental phenomena in the chromatin complex in eukaryotic cells---physical, for instance, long range interactions between enhancers and promoters, and chemical, such as epigenetic chromatin silencing. I begin by introducing the reader to both types of phenomena, and then set the stage for our strategy in the exploration of the physical side of these processes by creating a new machinery from existing pieces of polymer physics. I then make a brief foray into theoretical realms in an attempt to answer the question of what kinds of conformations of polymers dominate in what regimes. Subsequently, I proceed to consider the problem of analyzing and interpreting data from a major technique of probing the behavior of the chromatin complex in vivo --- Chromosome Conformation Capture --- towards which end we have developed and implemented a new and robust algorithm called 'G.R.O.M.A.T.I.N.'. Subsequently, I explore how similar ideas may be invoked in the analysis of direct microscopic observations of native chromatin structure via Fluorescence in situ Hybridization. Following this, I look at the problems of epigenetic chromatin silencing domain formation and stability in the presence of titration feedback and of stochastic noise, and demonstrate how the widely accepted polymerization model of silencing is consistent with Chromatin Immunoprecipitation data from silencing domains in budding yeast. I finally conclude with musings on recent evidence pinpointing the need to unify the physical and chemical pictures into one grand formulation.

Investigate the complex process in particle-fluid based surface generation technology using reactive molecular dynamics method

NASA Astrophysics Data System (ADS)

Han, Xuesong; Li, Haiyan; Zhao, Fu

2017-07-01

Particle-fluid based surface generation process has already become one of the most important materials processing technology for many advanced materials such as optical crystal, ceramics and so on. Most of the particle-fluid based surface generation technology involves two key process: chemical reaction which is responsible for surface softening; physical behavior which is responsible for materials removal/deformation. Presently, researchers cannot give a reasonable explanation about the complex process in the particle-fluid based surface generation technology because of the small temporal-spatial scale and the concurrent influence of physical-chemical process. Molecular dynamics (MD) method has already been proved to be a promising approach for constructing effective model of atomic scale phenomenon and can serve as a predicting simulation tool in analyzing the complex surface generation mechanism and is employed in this research to study the essence of surface generation. The deformation and piles of water molecule is induced with the feeding of abrasive particle which justifies the property mutation of water at nanometer scale. There are little silica molecule aggregation or materials removal because the water-layer greatly reduce the strength of mechanical interaction between particle and materials surface and minimize the stress concentration. Furthermore, chemical effect is also observed at the interface: stable chemical bond is generated between water and silica which lead to the formation of silconl and the reaction rate changes with the amount of water molecules in the local environment. Novel ring structure is observed in the silica surface and it is justified to be favored of chemical reaction with water molecule. The siloxane bond formation process quickly strengthened across the interface with the feeding of abrasive particle because of the compressive stress resulted by the impacting behavior.

Simplifying the complexity of a coupled carbon turnover and pesticide degradation model

NASA Astrophysics Data System (ADS)

Marschmann, Gianna; Erhardt, André H.; Pagel, Holger; Kügler, Philipp; Streck, Thilo

2016-04-01

The mechanistic one-dimensional model PECCAD (PEsticide degradation Coupled to CArbon turnover in the Detritusphere; Pagel et al. 2014, Biogeochemistry 117, 185-204) has been developed as a tool to elucidate regulation mechanisms of pesticide degradation in soil. A feature of this model is that it integrates functional traits of microorganisms, identifiable by molecular tools, and physicochemical processes such as transport and sorption that control substrate availability. Predicting the behavior of microbially active interfaces demands a fundamental understanding of factors controlling their dynamics. Concepts from dynamical systems theory allow us to study general properties of the model such as its qualitative behavior, intrinsic timescales and dynamic stability: Using a Latin hypercube method we sampled the parameter space for physically realistic steady states of the PECCAD ODE system and set up a numerical continuation and bifurcation problem with the open-source toolbox MatCont in order to obtain a complete classification of the dynamical system's behaviour. Bifurcation analysis reveals an equilibrium state of the system entirely controlled by fungal kinetic parameters. The equilibrium is generally unstable in response to small perturbations except for a small band in parameter space where the pesticide pool is stable. Time scale separation is a phenomenon that occurs in almost every complex open physical system. Motivated by the notion of "initial-stage" and "late-stage" decomposers and the concept of r-, K- or L-selected microbial life strategies, we test the applicability of geometric singular perturbation theory to identify fast and slow time scales of PECCAD. Revealing a generic fast-slow structure would greatly simplify the analysis of complex models of organic matter turnover by reducing the number of unknowns and parameters and providing a systematic mathematical framework for studying their properties.

Flash crashes, bursts, and black swans: parallels between financial markets and healthcare systems.

PubMed

West, Bruce J; Clancy, Thomas R

2010-11-01

As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on management in social organizations such as hospitals. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. This is the 16th in a series of articles applying complex systems science to the traditional management concepts of planning, organizing, directing, coordinating, and controlling. In this article, Dr Clancy, the editor of this column, and co-author, Dr West, discuss how the collapse of global financial markets in 2008 may provide valuable insight into mechanisms of complex system behavior in healthcare. Dr West, a physicist and expert in the field of complex systems and network science, is author of a chapter in the book, On the Edge: Nursing in the Age of Complexity (Lindberg C, Nash S, Linberg C. Bordertown, NJ: Plexus Press; 2008) and his most recent book, Disrupted Networks: From Physics to Climate Change (West BJ, Scafetta N. Singapore: Disrupted Networks, World Scientific Publishing; 2010).

Spiny lobsters use urine-borne olfactory signaling and physical aggressive behaviors to influence social status of conspecifics.

PubMed

Shabani, Shkelzen; Kamio, Michiya; Derby, Charles D

2009-08-01

Decapod crustaceans, like many other animals, engage in agonistic behaviors that enhance their ability to compete for resources with conspecifics. These agonistic behaviors include the release of chemical signals as well as physical aggressive and submissive behaviors. In this study, we report that Caribbean spiny lobsters, Panulirus argus, use both urine-borne chemical signaling and physical aggressive behaviors during interactions with conspecifics, and that these agonistic behaviors can influence the behavior and eventual social status of the interactants. Spiny lobsters that engaged primarily in physical aggressive behaviors became dominant, whereas spiny lobsters that received these physical aggressive behaviors responded with avoidance behaviors and became subordinates. Dominant animals frequently released urine during social interactions, more than when they were not in contact with subordinates and more than when they were not paired with another animal. Subordinates released urine significantly less often than dominants, and no more than when not paired. Preventing release of urine by catheterizing the animals resulted in an increase in the number and duration of physical interactions, and this increase was primarily driven by dominants initiating interactions through physical aggressive behaviors. Introducing urine from one of the catheterized animals into an aquarium reduced physical aggressive behavior by dominant animals to normal levels. Urine-borne signals alone were capable of inducing avoidance behaviors from solitary spiny lobsters in both laboratory and field conditions. We conclude that urine serves as a chemical signal that communicates social status to the interactants. Ablation experiments showed that that these urine signals are detected primarily by aesthetasc sensilla of the olfactory pathway.

Physical activity, sedentary behavior and their correlates in children with Autism Spectrum Disorder: A systematic review

PubMed Central

Downing, Katherine; Rinehart, Nicole J.; Barnett, Lisa M.; May, Tamara; McGillivray, Jane A.; Papadopoulos, Nicole V.; Skouteris, Helen; Timperio, Anna

2017-01-01

Autism Spectrum Disorder affects up to 2.5% of children and is associated with harmful health outcomes (e.g. obesity). Low levels of physical activity and high levels of sedentary behaviors may contribute to harmful health outcomes. To systematically review the prevalence and correlates of physical activity and sedentary behaviors in children with Autism Spectrum Disorder, electronic databases (PsycINFO, SPORTDiscus, EMBASE, Medline) were searched from inception to November 2015. The review was registered with PROSPERO (CRD42014013849). Peer-reviewed, English language studies were included. Two reviewers screened potentially relevant articles. Outcomes of interest were physical activity and sedentary behaviour levels and their potential correlates. Data were collected and analysed in 2015. Of 35 included studies, 15 reported physical activity prevalence, 10 reported physical activity correlates, 18 reported sedentary behavior prevalence, and 10 reported sedentary behavior correlates. Estimates of children’s physical activity (34–166 mins/day, average 86 mins/day) and sedentary behavior (126–558 mins/day in screen time, average 271 mins/day; 428–750 mins/day in total sedentary behavior, average 479 mins/day) varied across studies. Age was consistently inversely associated, and sex inconsistently associated with physical activity. Age and sex were inconsistently associated with sedentary behavior. Sample sizes were small. All but one of the studies were classified as having high risk of bias. Few correlates have been reported in sufficient studies to provide overall estimates of associations. Potential correlates in the physical environment remain largely unexamined. This review highlights varying levels of physical activity and sedentary behavior in children with Autism Spectrum Disorder. Research is needed to consistently identify the correlates of these behaviors. There is a critical need for interventions to support healthy levels of these behaviors. PMID:28245224

Physical activity behavior change in middle-aged and older women: the role of barriers and of environmental characteristics.

PubMed

Kowal, John; Fortier, Michelle Sheila

2007-06-01

The majority of North American women are insufficiently active. Using an ecological approach to examine physical activity behavior in a sample of middle-aged and older women, this study aimed to (1) describe barriers to physical activity behavior change as well as environmental characteristics present in their neighborhoods, (2) examine relationships between barriers and physical activity behavior change, and (3) investigate environmental characteristics that may contribute to physical activity behavior change. Participants were 149 women ranging in age between 39 and 68. At Time 1, self-reported physical activity was assessed. Six months later (Time 2), barriers and environmental characteristics were measured, and physical activity was re-assessed. The most prevalent barriers were daily activities and fatigue. Over time, inactive women reported higher levels of barriers (e.g. fatigue, lack of interest in physical activity) than women who remained active or increased their physical activity level. Certain environmental characteristics (e.g. enjoyable scenery, seeing others exercising in their neighborhood) are suggested as potential contributors to physical activity behavior change.

Modeling of dielectric elastomer as electromechanical resonator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Bo, E-mail: liboxjtu@mail.xjtu.edu.cn; Liu, Lei; Chen, Hualing

Dielectric elastomers (DEs) feature nonlinear dynamics resulting from an electromechanical coupling. Under alternating voltage, the DE resonates with tunable performances. We present an analysis of the nonlinear dynamics of a DE as electromechanical resonator (DEER) configured as a pure shear actuator. A theoretical model is developed to characterize the complex performance under different boundary conditions. Physical mechanisms are presented and discussed. Chaotic behavior is also predicted, illustrating instabilities in the dynamics. The results provide a guide to the design and application of DEER in haptic devices.

Shedding light on El Farol

NASA Astrophysics Data System (ADS)

Challet, Damien; Marsili, M.; Ottino, Gabriele

2004-02-01

We mathematize El Farol bar problem and transform it into a workable model. We find general conditions on the predictor space under which the convergence of the average attendance to the resource level does not require any intelligence on the side of the agents. Secondly, specializing to a particular ensemble of continuous strategies yields a model similar to the Minority Game. Statistical physics of disordered systems allows us to derive a complete understanding of the complex behavior of this model, on the basis of its phase diagram.

Bird song: in vivo, in vitro, in silico

NASA Astrophysics Data System (ADS)

Mukherjee, Aryesh; Mandre, Shreyas; Mahadevan, Lakshminarayan

2010-11-01

Bird song, long since an inspiration for artists, writers and poets also poses challenges for scientists interested in dissecting the mechanisms underlying the neural, motor, learning and behavioral systems behind the beak and brain, as a way to recreate and synthesize it. We use a combination of quantitative visualization experiments with physical models and computational theories to understand the simplest aspects of these complex musical boxes, focusing on using the controllable elastohydrodynamic interactions to mimic aural gestures and simple songs.

Integrated Social- and Neurocognitive Model of Physical Activity Behavior in Older Adults with Metabolic Disease.

PubMed

Olson, Erin A; Mullen, Sean P; Raine, Lauren B; Kramer, Arthur F; Hillman, Charles H; McAuley, Edward

2017-04-01

Despite the proven benefits of physical activity to treat and prevent metabolic diseases, such as diabetes (T2D) and metabolic syndrome (MetS), most individuals with metabolic disease do not meet physical activity (PA) recommendations. PA is a complex behavior requiring substantial motivational and cognitive resources. The purpose of this study was to examine social cognitive and neuropsychological determinants of PA behavior in older adults with T2D and MetS. The hypothesized model theorized that baseline self-regulatory strategy use and cognitive function would indirectly influence PA through self-efficacy. Older adults with T2D or MetS (M age  = 61.8 ± 6.4) completed either an 8-week physical activity intervention (n = 58) or an online metabolic health education course (n = 58) and a follow-up at 6 months. Measures included cognitive function, self-efficacy, self-regulatory strategy use, and PA. The data partially supported the hypothesized model (χ 2  = 158.535(131), p > .05, comparative fit index = .96, root mean square error of approximation = .04, standardized root mean square residual = .06) with self-regulatory strategy use directly predicting self-efficacy (β = .33, p < .05), which in turn predicted PA (β = .21, p < .05). Performance on various cognitive function tasks predicted PA directly and indirectly via self-efficacy. Baseline physical activity (β = .62, p < .01) and intervention group assignment via self-efficacy (β = -.20, p < .05) predicted follow-up PA. The model accounted for 54.4 % of the variance in PA at month 6. Findings partially support the hypothesized model and indicate that select cognitive functions (i.e., working memory, inhibition, attention, and task-switching) predicted PA behavior 6 months later. Future research warrants the development of interventions targeting cognitive function, self-regulatory skill development, and self-efficacy enhancement. The trial was registered with the clinical trial number NCT01790724.

Deterministic chaos and fractal complexity in the dynamics of cardiovascular behavior: perspectives on a new frontier.

PubMed

Sharma, Vijay

2009-09-10

Physiological systems such as the cardiovascular system are capable of five kinds of behavior: equilibrium, periodicity, quasi-periodicity, deterministic chaos and random behavior. Systems adopt one or more these behaviors depending on the function they have evolved to perform. The emerging mathematical concepts of fractal mathematics and chaos theory are extending our ability to study physiological behavior. Fractal geometry is observed in the physical structure of pathways, networks and macroscopic structures such the vasculature and the His-Purkinje network of the heart. Fractal structure is also observed in processes in time, such as heart rate variability. Chaos theory describes the underlying dynamics of the system, and chaotic behavior is also observed at many levels, from effector molecules in the cell to heart function and blood pressure. This review discusses the role of fractal structure and chaos in the cardiovascular system at the level of the heart and blood vessels, and at the cellular level. Key functional consequences of these phenomena are highlighted, and a perspective provided on the possible evolutionary origins of chaotic behavior and fractal structure. The discussion is non-mathematical with an emphasis on the key underlying concepts.

Deterministic Chaos and Fractal Complexity in the Dynamics of Cardiovascular Behavior: Perspectives on a New Frontier

PubMed Central

Sharma, Vijay

2009-01-01

Physiological systems such as the cardiovascular system are capable of five kinds of behavior: equilibrium, periodicity, quasi-periodicity, deterministic chaos and random behavior. Systems adopt one or more these behaviors depending on the function they have evolved to perform. The emerging mathematical concepts of fractal mathematics and chaos theory are extending our ability to study physiological behavior. Fractal geometry is observed in the physical structure of pathways, networks and macroscopic structures such the vasculature and the His-Purkinje network of the heart. Fractal structure is also observed in processes in time, such as heart rate variability. Chaos theory describes the underlying dynamics of the system, and chaotic behavior is also observed at many levels, from effector molecules in the cell to heart function and blood pressure. This review discusses the role of fractal structure and chaos in the cardiovascular system at the level of the heart and blood vessels, and at the cellular level. Key functional consequences of these phenomena are highlighted, and a perspective provided on the possible evolutionary origins of chaotic behavior and fractal structure. The discussion is non-mathematical with an emphasis on the key underlying concepts. PMID:19812706

Calculation of thermomechanical fatigue life based on isothermal behavior

NASA Technical Reports Server (NTRS)

Halford, Gary R.; Saltsman, James F.

1987-01-01

The isothermal and thermomechanical fatigue (TMF) crack initiation response of a hypothetical material was analyzed. Expected thermomechanical behavior was evaluated numerically based on simple, isothermal, cyclic stress-strain - time characteristics and on strainrange versus cyclic life relations that have been assigned to the material. The attempt was made to establish basic minimum requirements for the development of a physically accurate TMF life-prediction model. A worthy method must be able to deal with the simplest of conditions: that is, those for which thermal cycling, per se, introduces no damage mechanisms other than those found in isothermal behavior. Under these assumed conditions, the TMF life should be obtained uniquely from known isothermal behavior. The ramifications of making more complex assumptions will be dealt with in future studies. Although analyses are only in their early stages, considerable insight has been gained in understanding the characteristics of several existing high-temperature life-prediction methods. The present work indicates that the most viable damage parameter is based on the inelastic strainrange.

Is management still a science?

PubMed

Freedman, D H

1992-01-01

New technologies are transforming products, markets, and entire industries. Yet the more science and technology reshape the essence of business, the less useful the concept of management itself as a science seems to be. On reflection, this paradox is not so surprising. The traditional scientific approach to management promised to provide managers with the capacity to analyze, predict, and control the behavior of the complex organizations they led. But the world most managers currently inhabit often appears to be unpredictable, uncertain, and even uncontrollable. In the face of this more volatile business environment, the old-style mechanisms of "scientific management" seem positively counterproductive. And science itself appears less and less relevant to the practical concerns of managers. In this article, science journalist David Freedman argues that the problem lies less in the shortcomings of a scientific approach to management than in managers' understanding of science. What most managers think of as scientific management is based on a conception of science that few current scientists would defend. What's more, just as managers have become more preoccupied with the volatility of the business environment, scientists have also become preoccupied with the inherent volatility--the "chaos" and "complexity"--of nature. They are developing new rules for complex behavior in physical systems that have intriguing parallels to the kind of organizational behaviors companies are trying to encourage. In fact, science, long esteemed by business as a source of technological innovation, may ultimately prove of greatest value to managers as a source of something else: useful ways of looking at the world.

Rheological Behavior of a Novel Organic-Inorganic Hybrid: Micro/Nano-Tin Fluorophosphate Glass-Polycarbonate.

PubMed

Yang, Jing; Liu, Huiwen; Yu, Honglin; Zou, Xiaoxuan; Jing, Bo; Dai, Wenli

2016-03-01

The rheological behavior of a novel, binary organic-inorganic hybrid consisting of an ultra-low Tg tin fluorophosphate glass (Pglass) and polycarbonate (PC) was investigated using oscillatory rheometry. It was found that the complex viscosity of the hybrid showed Pglass content dependence. Under low Pglass content (10-30%), the complex viscosity of the hybrid was lower than that of pure PC. While the complex viscosity was dramatically increased and higher than that of pure PC with the content of Pglass above 30%. This phenomenon was particularly remarkable at low frequencies. Besides, with the addition of Pglass the hybrid material exhibited shear-thinning behavior and the shear-thinning characteristics became more obvious with the enhancement of the Pglass content, indicating the presence of nonlinear chemical and physical interactions between the hybrid components. Differential scanning calorimetry (DSC) measurements revealed that increasing the content of Pglass caused a decrease of the glass transition temperature (Tg) of the hybrids, suggesting that Pglass was acting as a macromolecular plasticizer for the PC. The microstructure of the Pglass in the hybrid material was characterized by scanning electron microscopy (SEM). The results showed that the Pglass were dispersed as micro- and nano-bead in the continuous phase of PC and the Pglass appeared aggregation partly with the increase of the Pglass content. This contribution was anticipated to be a guideline for the processing of this promising new class of hybrid materials.

Implications of the stability behavior of zinc oxide nanoparticles for toxicological studies

NASA Astrophysics Data System (ADS)

Meißner, Tobias; Oelschlägel, Kathrin; Potthoff, Annegret

2014-08-01

The increasing use of zinc oxide (ZnO) nanoparticles in sunscreens and other cosmetic products demands a risk assessment that has to be done in toxicological studies. Such investigations require profound knowledge of the behavior of ZnO in cell culture media. The current study was performed to get well-dispersed suspensions of a hydrophilic (ZnO-hydro) and a lipophilic coated (ZnO-lipo) ZnO nanomaterial for use in in vitro tests. Therefore, systematic tests were carried out with common dispersants (phosphate, lecithin, proteins) to elucidate chemical and physical changes of ZnO nanoparticles in water and physiological solutions (PBS, DMEM). Non-physiological stock suspensions were prepared using ultrasonication. Time-dependent changes of pH, conductivity, zeta potential, particle size and dissolution were recorded. Secondly, the stock suspensions were added to physiological media with or without albumin (BSA) or serum (FBS), to examine characteristics such as agglomeration and dissolution. Stable stock suspensions were obtained using phosphate as natural and physiological electrostatic stabilizing agent. Lecithin proved to be an effective wetting agent for ZnO-lipo. Although the particle size remained constant, the suspension changed over time. The pH increased as a result of ZnO dissolution and formation of zinc phosphate complexes. The behavior of ZnO in physiological media was found to depend strongly on the additives used. Applying only phosphate as additive, ZnO-hydro agglomerated within minutes. In the presence of lecithin or BSA/serum, agglomeration was inhibited. ZnO dissolution was higher under physiological conditions than in the stock suspension. Serum especially promoted this process. Using body-related dispersants (phosphate, lecithin) non-agglomerating stock suspensions of hydrophilic and lipophilic ZnO were prepared as a prerequisite to perform meaningful toxicological investigation. Both nanomaterials showed a non-negligible dissolution behavior that strongly depended on the surrounding conditions. Agglomeration of ZnO particles in physiological media is a complex function of particle coating, used dispersants and serum proteins if supplemented. The present study gives a clear guideline how to prepare and handle suspensions with ZnO for in vitro testing and allows the correlation between the chemical-physical particles behavior with findings from toxicological tests.

Monitoring dietary intake and physical activity electronically: feasibility, usability, and ecological validity of a mobile-based Ecological Momentary Assessment tool.

PubMed

Spook, Jorinde Eline; Paulussen, Theo; Kok, Gerjo; Van Empelen, Pepijn

2013-09-24

Despite the growing body of research on complex lifestyle behaviors (eg, Dietary Intake [DI] and Physical Activity [PA]), monitoring of these behaviors has been hampered by a lack of suitable methods. A possible solution to this deficiency is mobile-based Ecological Momentary Assessment (mEMA), which enables researchers to collect data on participants' states in real-time by means of a smartphone application. However, feasibility, usability, and ecological validity need to be anticipated and managed in order to enhance the validity of mEMA. To examine the feasibility, usability, and ecological validity of a mEMA application (app) with regard to DI and PA among Dutch vocational education students. The students (n=30) participated in the mEMA study for seven consecutive days. They downloaded the mEMA app on their smartphone. Feasibility and usability of the mEMA app were evaluated by completing an online evaluation after seven days of participation. Ecological validity was measured by assessing the degree to which the content of the mEMA app approximated the real-world setting that was being examined, through several multiple-choice questions. Compliance rates, as registered by the mEMA app, declined 46% over a seven-day period, while self-reported compliance, as measured with an online evaluation questionnaire afterwards, indicated a smaller decrease in compliance (29%). The students evaluated the mEMA app as feasible and usable. Ecological validity analyses showed that all DI and almost all PA multiple-choice options were covered with the compound response categories. The mEMA app offers the opportunity to assess complex health behaviors (eg, DI and PA) in real-time settings, in which specifically routinized behaviors are involved. However, the mEMA app faced several challenges that needed to be overcome in order to improve its validity. Overall, the present study showed that the mEMA app is a usable and ecologically valid tool to measure DI and PA behaviors among vocational education students, but compliance is still limited.

Predicting Physical Interactions between Protein Complexes*

PubMed Central

Clancy, Trevor; Rødland, Einar Andreas; Nygard, Ståle; Hovig, Eivind

2013-01-01

Protein complexes enact most biochemical functions in the cell. Dynamic interactions between protein complexes are frequent in many cellular processes. As they are often of a transient nature, they may be difficult to detect using current genome-wide screens. Here, we describe a method to computationally predict physical interactions between protein complexes, applied to both humans and yeast. We integrated manually curated protein complexes and physical protein interaction networks, and we designed a statistical method to identify pairs of protein complexes where the number of protein interactions between a complex pair is due to an actual physical interaction between the complexes. An evaluation against manually curated physical complex-complex interactions in yeast revealed that 50% of these interactions could be predicted in this manner. A community network analysis of the highest scoring pairs revealed a biologically sensible organization of physical complex-complex interactions in the cell. Such analyses of proteomes may serve as a guide to the discovery of novel functional cellular relationships. PMID:23438732

The Usability of Rock-Like Materials for Numerical Studies on Rocks

NASA Astrophysics Data System (ADS)

Zengin, Enes; Abiddin Erguler, Zeynal

2017-04-01

The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and artificial simulations. The results obtained from these laboratory tests and modelling studies were compared with the other researcher's studies in respect to failure mechanism of different type of rocks. It can be concluded that there is similar failure mechanism between concrete and rock materials. Therefore, the results obtained from concrete samples that would be prepared at different porosity and pore sizes can be used in future studies in selection micro-mechanical and physical properties to constitute synthetic rock materials for understanding failure mechanism of rocks having complex inherent structures such as vuggy rocks or heavily jointed rock masses.

Biochemical characterization of GM1 micelles-Amphotericin B interaction.

PubMed

Leonhard, Victoria; Alasino, Roxana V; Bianco, Ismael D; Garro, Ariel G; Heredia, Valeria; Beltramo, Dante M

2015-01-01

In this work a thorough characterization of the GM1 micelle-Amphotericin B (AmB) interaction was performed. The micelle formation as well as the drug loading occurs spontaneously, although influenced by the physicochemical conditions, pH and temperature. The chromatographic profile of GM1-AmB complexes at different molar ratios shows the existence of two populations. The differential absorbance of GM1, monomeric and aggregate AmB, allowed us to discriminate the presence of all of them in both fractions. Thus, we noted that at higher proportion of AmB in the complex, increases the larger population which is composed mainly of aggregated AmB. The physical behavior of these micelles shows that both GM1- AmB complexes were stable in solution for at least 30 days. However upon freeze-thawing or lyophilization-solubilization cycles, only the smallest population, enriched in monomeric AmB, showed a complete solubilization. In vitro, GM1-AmB micelles were significantly less toxic on cultured cells than other commercial micellar formulations as Fungizone, but had a similar behavior to liposomal formulations as Ambisome. Regarding the antifungal activity of the new formulation, it was very similar to that of other formulations. The characterization of these GM1-AmB complexes is discussed as a potential new formulation able to improve the antifungal therapeutic efficiency of AmB.

Constructing the tree-level Yang-Mills S-matrix using complex factorization

NASA Astrophysics Data System (ADS)

Schuster, Philip C.; Toro, Natalia

2009-06-01

A remarkable connection between BCFW recursion relations and constraints on the S-matrix was made by Benincasa and Cachazo in 0705.4305, who noted that mutual consistency of different BCFW constructions of four-particle amplitudes generates non-trivial (but familiar) constraints on three-particle coupling constants — these include gauge invariance, the equivalence principle, and the lack of non-trivial couplings for spins > 2. These constraints can also be derived with weaker assumptions, by demanding the existence of four-point amplitudes that factorize properly in all unitarity limits with complex momenta. From this starting point, we show that the BCFW prescription can be interpreted as an algorithm for fully constructing a tree-level S-matrix, and that complex factorization of general BCFW amplitudes follows from the factorization of four-particle amplitudes. The allowed set of BCFW deformations is identified, formulated entirely as a statement on the three-particle sector, and using only complex factorization as a guide. Consequently, our analysis based on the physical consistency of the S-matrix is entirely independent of field theory. We analyze the case of pure Yang-Mills, and outline a proof for gravity. For Yang-Mills, we also show that the well-known scaling behavior of BCFW-deformed amplitudes at large z is a simple consequence of factorization. For gravity, factorization in certain channels requires asymptotic behavior ~ 1/z2.

Correlates of urban children's leisure-time physical activity and sedentary behaviors during school days.

PubMed

Marques, Adilson; Sallis, James F; Martins, João; Diniz, José; Carreiro Da Costa, Francisco

2014-01-01

Understanding correlates of physical activity and sedentary behaviors may contribute to fostering active lifestyles. This study aimed to identify correlates of physical activity and sedentary behaviors in leisure-time among Portuguese urban children, during school days. A cross-sectional survey was conducted with 802 students (416 boys), aged 10-12 years. A questionnaire was used to collect data of physical activity, sedentary behaviors, psychological and behavioral variables related to physical activity and sedentary behaviors. Analyses were run separately for boys and girls. Television viewing occupied the most leisure-time of boys and girls, followed by computer usage, and video game playing. These behaviors occupied 259.7 min/day for boys and 208.6 for girls (P = 0.002). Reported moderate-to-vigorous physical activity was 23.7 min for boys and 12.8 min for girls (P < 0.001). Perception of competence and academic achievement were related to physical activity for the boys and girls. Computer use and playing video games with friends were only related to physical activity for the boys. On the other hand, parents' physical activity participation was related with boys' and girls' physical activity. The correlates of sedentary behavior were outdoor play for the boys, age for the girls, and playing video games with friends for both. This finding suggests that interventions should be considered to replace joint video game time with joint physical activity time. Copyright © 2014 Wiley Periodicals, Inc.

Associations between sleep duration and physical activity and dietary behaviors in Chinese adolescents: results from the Youth Behavioral Risk Factor Surveys of 2015.

PubMed

Gong, Qing Hai; Li, Hui; Zhang, Xiao Hong; Zhang, Tao; Cui, Jun; Xu, Guo Zhang

2017-09-01

To assess the association between sleep duration and physical activity and dietary behaviors among adolescents in a representative sample. The analysis was performed using data from the 2015 Ningbo Youth Risk Behavior Survey. Associations between physical activity and dietary behaviors and sleep duration were examined on weighted data using logistic regression. Of the 10726 students, roughly 40% reported sleep duration <8 h. Longer sleep duration was associated with higher likelihood of milk intake, fruit consumption, vegetable consumption, water consumption, moderate physical activity, and muscle-strengthening physical activity, and with a lower likelihood of cigarette use, alcohol use, sweets intake, Western fast food intake, and breakfast skipping. Insufficient sleep may be common among Chinese adolescents. Sleep duration was associated with dietary behaviors, physical activity, and other health-related behaviors. These findings suggest that sleep duration could be a potential target for many health-risk behaviors in young adolescents. Copyright © 2017. Published by Elsevier B.V.

Complex adaptive behavior and dexterous action

PubMed Central

Harrison, Steven J.; Stergiou, Nicholas

2016-01-01

Dexterous action, as conceptualized by Bernstein in his influential ecological analysis of human behavior, is revealed in the ability to flexibly generate behaviors that are adaptively tailored to the demands of the context in which they are embedded. Conceived as complex adaptive behavior, dexterity depends upon the qualities of robustness and degeneracy, and is supported by the functional complexity of the agent-environment system. Using Bernstein’s and Gibson’s ecological analyses of behavior situated in natural environments as conceptual touchstones, we consider the hypothesis that complex adaptive behavior capitalizes upon general principles of self-organization. Here, we outline a perspective in which the complex interactivity of nervous-system, body, and environment is revealed as an essential resource for adaptive behavior. From this perspective, we consider the implications for interpreting the functionality and dysfunctionality of human behavior. This paper demonstrates that, optimal variability, the topic of this special issue, is a logical consequence of interpreting the functionality of human behavior as complex adaptive behavior. PMID:26375932

Statistical physics of the symmetric group.

PubMed

Williams, Mobolaji

2017-04-01

Ordered chains (such as chains of amino acids) are ubiquitous in biological cells, and these chains perform specific functions contingent on the sequence of their components. Using the existence and general properties of such sequences as a theoretical motivation, we study the statistical physics of systems whose state space is defined by the possible permutations of an ordered list, i.e., the symmetric group, and whose energy is a function of how certain permutations deviate from some chosen correct ordering. Such a nonfactorizable state space is quite different from the state spaces typically considered in statistical physics systems and consequently has novel behavior in systems with interacting and even noninteracting Hamiltonians. Various parameter choices of a mean-field model reveal the system to contain five different physical regimes defined by two transition temperatures, a triple point, and a quadruple point. Finally, we conclude by discussing how the general analysis can be extended to state spaces with more complex combinatorial properties and to other standard questions of statistical mechanics models.

Statistical physics of the symmetric group

NASA Astrophysics Data System (ADS)

Williams, Mobolaji

2017-04-01

Ordered chains (such as chains of amino acids) are ubiquitous in biological cells, and these chains perform specific functions contingent on the sequence of their components. Using the existence and general properties of such sequences as a theoretical motivation, we study the statistical physics of systems whose state space is defined by the possible permutations of an ordered list, i.e., the symmetric group, and whose energy is a function of how certain permutations deviate from some chosen correct ordering. Such a nonfactorizable state space is quite different from the state spaces typically considered in statistical physics systems and consequently has novel behavior in systems with interacting and even noninteracting Hamiltonians. Various parameter choices of a mean-field model reveal the system to contain five different physical regimes defined by two transition temperatures, a triple point, and a quadruple point. Finally, we conclude by discussing how the general analysis can be extended to state spaces with more complex combinatorial properties and to other standard questions of statistical mechanics models.

Fullerol ionic fluids.

PubMed

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B; Georgakilas, Vasilios; Giannelis, Emmanuel P

2010-09-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine (liquid-like) and the control (solid-like).

Fullerol ionic fluids

NASA Astrophysics Data System (ADS)

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-09-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like).

Perspectives Regarding Adherence to Prescribed Treatment in Highly Adherent HIV-Infected Gay Men.

PubMed

Brion, John M; Menke, Edna M

2008-01-01

Focus group methodology was used to describe the medication adherence experience of 24 HIV-infected gay men who reported being adherent to their medication regimens. A conceptualization of medication adherence as an evolving process consisted of challenges to adherence (learning the diagnosis, starting the medications, struggling with the medications, dealing with side effects, coping with stigma) as well as those factors supportive of adherence (believing in medications, finding motivating factors, using reminders, depending on others, owning the disease). Themes associated with challenges to adherence focused on diagnosis and the physical and emotional adjustments individuals made to incorporate antiretroviral medications into their daily lives and move toward medication adherence. The factors supportive of adherence were related to the ongoing behaviors identified with establishing and maintaining adherence behaviors. What can be taken from the study is that adherence is a complex and dynamic process rather than a static behavior.

Game theory and neural basis of social decision making

PubMed Central

Lee, Daeyeol

2008-01-01

Decision making in a social group displays two unique features. First, humans and other animals routinely alter their behaviors in response to changes in their physical and social environment. As a result, the outcomes of decisions that depend on the behaviors of multiple decision makers are difficult to predict, and this requires highly adaptive decision-making strategies. Second, decision makers may have other-regarding preferences and therefore choose their actions to improve or reduce the well-beings of others. Recently, many neurobiological studies have exploited game theory to probe the neural basis of decision making, and found that these unique features of social decision making might be reflected in the functions of brain areas involved in reward evaluation and reinforcement learning. Molecular genetic studies have also begun to identify genetic mechanisms for personal traits related to reinforcement learning and complex social decision making, further illuminating the biological basis of social behavior. PMID:18368047

High-resolution behavioral mapping of electric fishes in Amazonian habitats.

PubMed

Madhav, Manu S; Jayakumar, Ravikrishnan P; Demir, Alican; Stamper, Sarah A; Fortune, Eric S; Cowan, Noah J

2018-04-11

The study of animal behavior has been revolutionized by sophisticated methodologies that identify and track individuals in video recordings. Video recording of behavior, however, is challenging for many species and habitats including fishes that live in turbid water. Here we present a methodology for identifying and localizing weakly electric fishes on the centimeter scale with subsecond temporal resolution based solely on the electric signals generated by each individual. These signals are recorded with a grid of electrodes and analyzed using a two-part algorithm that identifies the signals from each individual fish and then estimates the position and orientation of each fish using Bayesian inference. Interestingly, because this system involves eavesdropping on electrocommunication signals, it permits monitoring of complex social and physical interactions in the wild. This approach has potential for large-scale non-invasive monitoring of aquatic habitats in the Amazon basin and other tropical freshwater systems.

Herbal medicine, radical scavenger and metal detoxification: bioinorganic, complexity and nano science perspectives

NASA Astrophysics Data System (ADS)

Sumitro, Sutiman B.; Alit, Sukmaningsih

2018-03-01

Developing Complexity Science and Nano Biological perspective giving the ideas of interfacing between modern physical and biological sciences for more comprehensive understanding of life. The study of bioinorganic is a trans-disciplinary, and will initiate the way to more comprehensive and better understanding life. We can talk about energy generation, motive forces and energy transfer at the level of macromolecules. We can then develop understanding biological behavior on nano size biological materials and its higher order using modern physics as well as thermodynamic law. This is a necessity to ovoid partial understanding of life that are not match with holism. In animal tissues, the accumulation or overwhelmed production of free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases. Thus a guarded balance of radical species is imperative. Edward Kosower [1] proposed an idea of biradical in an aromatic organic compounds. Each of which having unpaired electrons. The magnetic force of this compound used for making agregation based on their magnetic characters. Bioinorganic low molecular weight complex compounds composing herbal medicine can bind toxic metals. This low molecular weight complex molecules then easily excerted the metals from the body, removing them from their either intracellular or extracellular existences. This bioinorganic chelation potential is now inspiring a new therapeutic strategies.

An Applied Ecological Framework for Evaluating Infrastructure to Promote Walking and Cycling: The iConnect Study

PubMed Central

Bull, Fiona; Powell, Jane; Cooper, Ashley R.; Brand, Christian; Mutrie, Nanette; Preston, John; Rutter, Harry

2011-01-01

Improving infrastructure for walking and cycling is increasingly recommended as a means to promote physical activity, prevent obesity, and reduce traffic congestion and carbon emissions. However, limited evidence from intervention studies exists to support this approach. Drawing on classic epidemiological methods, psychological and ecological models of behavior change, and the principles of realistic evaluation, we have developed an applied ecological framework by which current theories about the behavioral effects of environmental change may be tested in heterogeneous and complex intervention settings. Our framework guides study design and analysis by specifying the most important data to be collected and relations to be tested to confirm or refute specific hypotheses and thereby refine the underlying theories. PMID:21233429

Emerging interdependence between stock values during financial crashes.

PubMed

Rocchi, Jacopo; Tsui, Enoch Yan Lok; Saad, David

2017-01-01

To identify emerging interdependencies between traded stocks we investigate the behavior of the stocks of FTSE 100 companies in the period 2000-2015, by looking at daily stock values. Exploiting the power of information theoretical measures to extract direct influences between multiple time series, we compute the information flow across stock values to identify several different regimes. While small information flows is detected in most of the period, a dramatically different situation occurs in the proximity of global financial crises, where stock values exhibit strong and substantial interdependence for a prolonged period. This behavior is consistent with what one would generally expect from a complex system near criticality in physical systems, showing the long lasting effects of crashes on stock markets.

Adaptive Crack Modeling with Interface Solid Elements for Plain and Fiber Reinforced Concrete Structures.

PubMed

Zhan, Yijian; Meschke, Günther

2017-07-08

The effective analysis of the nonlinear behavior of cement-based engineering structures not only demands physically-reliable models, but also computationally-efficient algorithms. Based on a continuum interface element formulation that is suitable to capture complex cracking phenomena in concrete materials and structures, an adaptive mesh processing technique is proposed for computational simulations of plain and fiber-reinforced concrete structures to progressively disintegrate the initial finite element mesh and to add degenerated solid elements into the interfacial gaps. In comparison with the implementation where the entire mesh is processed prior to the computation, the proposed adaptive cracking model allows simulating the failure behavior of plain and fiber-reinforced concrete structures with remarkably reduced computational expense.

Adaptive Crack Modeling with Interface Solid Elements for Plain and Fiber Reinforced Concrete Structures

PubMed Central

Zhan, Yijian

2017-01-01

The effective analysis of the nonlinear behavior of cement-based engineering structures not only demands physically-reliable models, but also computationally-efficient algorithms. Based on a continuum interface element formulation that is suitable to capture complex cracking phenomena in concrete materials and structures, an adaptive mesh processing technique is proposed for computational simulations of plain and fiber-reinforced concrete structures to progressively disintegrate the initial finite element mesh and to add degenerated solid elements into the interfacial gaps. In comparison with the implementation where the entire mesh is processed prior to the computation, the proposed adaptive cracking model allows simulating the failure behavior of plain and fiber-reinforced concrete structures with remarkably reduced computational expense. PMID:28773130

Measuring masculinity in research on men of color: findings and future directions.

PubMed

Griffith, Derek M; Gunter, Katie; Watkins, Daphne C

2012-05-01

The purpose of this study was to examine the association between masculinity and the health of US men of color aged 18 years and older. We identified 22 population-based studies that included a measure of masculinity and a measure of health behavior, mental health, or physical health. The associations between masculinity and health were complex and varied by construct and health outcome, though they generally were significant in the hypothesized directions. Future research should explore the centrality of masculinity versus other identities and characteristics, how the relationship between masculinity and health varies by health outcome, and the identification of the conceptions and aspects of masculinity that are most relevant to and associated with specific health behaviors and health outcomes.

Measuring Masculinity in Research on Men of Color: Findings and Future Directions

PubMed Central

Gunter, Katie; Watkins, Daphne C.

2012-01-01

The purpose of this study was to examine the association between masculinity and the health of US men of color aged 18 years and older. We identified 22 population-based studies that included a measure of masculinity and a measure of health behavior, mental health, or physical health. The associations between masculinity and health were complex and varied by construct and health outcome, though they generally were significant in the hypothesized directions. Future research should explore the centrality of masculinity versus other identities and characteristics, how the relationship between masculinity and health varies by health outcome, and the identification of the conceptions and aspects of masculinity that are most relevant to and associated with specific health behaviors and health outcomes. PMID:22401519

Emerging interdependence between stock values during financial crashes

PubMed Central

Tsui, Enoch Yan Lok; Saad, David

2017-01-01

To identify emerging interdependencies between traded stocks we investigate the behavior of the stocks of FTSE 100 companies in the period 2000-2015, by looking at daily stock values. Exploiting the power of information theoretical measures to extract direct influences between multiple time series, we compute the information flow across stock values to identify several different regimes. While small information flows is detected in most of the period, a dramatically different situation occurs in the proximity of global financial crises, where stock values exhibit strong and substantial interdependence for a prolonged period. This behavior is consistent with what one would generally expect from a complex system near criticality in physical systems, showing the long lasting effects of crashes on stock markets. PMID:28542278

Sitting Behavior and Physical Activity of College Students: Implications for Health Education and Promotion

ERIC Educational Resources Information Center

D'Abundo, Michelle Lee; Sidman, Cara L.; Fiala, Kelly A.

2015-01-01

The purpose of this study was to provide a baseline assessment of sitting behaviors and physical activity among college students in a physical activity and wellness course. The International Physical Activity Questionnaire (IPAQ) was used to measure the physical activity and sitting behaviors of college students. Independent t-tests and ANOVAs…

The behavioral genetics of nonhuman primates: Status and prospects.

PubMed

Rogers, Jeffrey

2018-01-01

The complexity and diversity of primate behavior have long attracted the attention of ethologists, psychologists, behavioral ecologists, and neuroscientists. Recent studies have advanced our understanding of the nature of genetic influences on differences in behavior among individuals within species. A number of analyses have focused on the genetic analysis of behavioral reactions to specific experimental tests, providing estimates of the degree of genetic control over reactivity, and beginning to identify the genes involved. Substantial progress is also being made in identifying genetic factors that influence the structure and function of the primate brain. Most of the published studies on these topics have examined either cercopithecines or chimpanzees, though a few studies have addressed these questions in other primate species. One potentially important line of research is beginning to identify the epigenetic processes that influence primate behavior, thus revealing specific cellular and molecular mechanisms by which environmental experiences can influence gene expression or gene function relevant to behavior. This review summarizes many of these studies of non-human primate behavioral genetics. The primary focus is on analyses that address the nature of the genes and genetic processes that affect differences in behavior among individuals within non-human primate species. Analyses of between species differences and potential avenues for future research are also discussed. © 2018 American Association of Physical Anthropologists.

USE OF TRANS-CONTEXTUAL MODEL-BASED PHYSICAL ACTIVITY COURSE IN DEVELOPING LEISURE-TIME PHYSICAL ACTIVITY BEHAVIOR OF UNIVERSITY STUDENTS.

PubMed

Müftüler, Mine; İnce, Mustafa Levent

2015-08-01

This study examined how a physical activity course based on the Trans-Contextual Model affected the variables of perceived autonomy support, autonomous motivation, determinants of leisure-time physical activity behavior, basic psychological needs satisfaction, and leisure-time physical activity behaviors. The participants were 70 Turkish university students (M age=23.3 yr., SD=3.2). A pre-test-post-test control group design was constructed. Initially, the participants were randomly assigned into an experimental (n=35) and a control (n=35) group. The experimental group followed a 12 wk. trans-contextual model-based intervention. The participants were pre- and post-tested in terms of Trans-Contextual Model constructs and of self-reported leisure-time physical activity behaviors. Multivariate analyses showed significant increases over the 12 wk. period for perceived autonomy support from instructor and peers, autonomous motivation in leisure-time physical activity setting, positive intention and perceived behavioral control over leisure-time physical activity behavior, more fulfillment of psychological needs, and more engagement in leisure-time physical activity behavior in the experimental group. These results indicated that the intervention was effective in developing leisure-time physical activity and indicated that the Trans-Contextual Model is a useful way to conceptualize these relationships.

The science of complexity and the role of mathematics

NASA Astrophysics Data System (ADS)

Bountis, T.; Johnson, J.; Provata, A.; Tsironis, G.

2016-09-01

In the middle of the second decade of the 21st century, Complexity Science has reached a turning point. Its rapid advancement over the last 30 years has led to remarkable new concepts, methods and techniques, whose applications to complex systems of the physical, biological and social sciences has produced a great number of exciting results. The approach has so far depended almost exclusively on the solution of a wide variety of mathematical models by sophisticated numerical techniques and extensive simulations that have inspired a new generation of researchers interested in complex systems. Still, the impact of Complexity beyond the natural sciences, its applications to Medicine, Technology, Economics, Society and Policy are only now beginning to be explored. Furthermore, its basic principles and methods have so far remained within the realm of high level research institutions, out of reach of society's urgent need for practical applications. To address these issues, evaluate the current situation and bring Complexity Science closer to university students, a series of Ph.D. Schools on Mathematical Modeling of Complex Systems was launched, starting in July 2011 at the University of Patras, Greece (see http://www.math.upatras.gr/˜phdsch11). These Schools lasted two weeks each and included, beyond introductory lectures, a conference component of 2-3 days where students were exposed to recent results mainly presented by young researchers. The Ph.D. Schools continued successfully, the 2nd one taking place at Pescara, Italy (2012), (see http://www.nodycosy.unich.it), the 3d one at Heraklion, Crete, Greece (2013) (see http://nlsconf2013.physics.uoc.gr) and the 4th one in Athens, Greece (2014) (see http://nlsconf2014.physics.uoc.gr) (2014). This Special Theme volume contains the proceedings of the 5th Ph.D. School-Conference of this series held at the University of Patras, Greece, 20 30 July, 2015 (see http://www.math.upatras.gr/˜phdsch15) and includes many of the introductory lectures and research talks presented at this event. The primary concern of all those that participated in these events was to emphasize the role of mathematics, modeling and numerical simulation, which are indispensable for understanding what we call complex behavior of physical, biological, technological and socio - economical systems. In the discussions that took place, a great number of participants expressed the need to formulate a unifying theory of complex systems based on the main conclusions that have been reached so far in the science of Complexity. As Guest Editors of this volume, we also feel that it is important to reach some fundamental conclusions concerning common phenomena, theories and methodologies that arise in Complexity. We should all work to explore common rules and approaches, particularly in view of the remarkable challenges that face us all regarding complex social problems that threaten present day society and civilization as we know them.

Polymer Physics Prize Talk

NASA Astrophysics Data System (ADS)

Olvera de La Cruz, Monica

Polymer electrolytes have been particularly difficult to describe theoretically given the large number of disparate length scales involved in determining their physical properties. The Debye length, the Bjerrum length, the ion size, the chain length, and the distance between the charges along their backbones determine their structure and their response to external fields. We have developed an approach that uses multi-scale calculations with the capability of demonstrating the phase behavior of polymer electrolytes and of providing a conceptual understanding of how charge dictates nano-scale structure formation. Moreover, our molecular dynamics simulations have provided an understanding of the coupling of their conformation to their dynamics, which is crucial to design self-assembling materials, as well as to explore the dynamics of complex electrolytes for energy storage and conversion applications.

Numerical Studies of Impurities in Fusion Plasmas

DOE R&D Accomplishments Database

Hulse, R. A.

1982-09-01

The coupled partial differential equations used to describe the behavior of impurity ions in magnetically confined controlled fusion plasmas require numerical solution for cases of practical interest. Computer codes developed for impurity modeling at the Princeton Plasma Physics Laboratory are used as examples of the types of codes employed for this purpose. These codes solve for the impurity ionization state densities and associated radiation rates using atomic physics appropriate for these low-density, high-temperature plasmas. The simpler codes solve local equations in zero spatial dimensions while more complex cases require codes which explicitly include transport of the impurity ions simultaneously with the atomic processes of ionization and recombination. Typical applications are discussed and computational results are presented for selected cases of interest.

Exact solutions for oscillatory shear sweep behaviors of complex fluids from the Oldroyd 8-constant framework

NASA Astrophysics Data System (ADS)

Saengow, Chaimongkol; Giacomin, A. Jeffrey

2018-03-01

In this paper, we provide a new exact framework for analyzing the most commonly measured behaviors in large-amplitude oscillatory shear flow (LAOS), a popular flow for studying the nonlinear physics of complex fluids. Specifically, the strain rate sweep (also called the strain sweep) is used routinely to identify the onset of nonlinearity. By the strain rate sweep, we mean a sequence of LAOS experiments conducted at the same frequency, performed one after another, with increasing shear rate amplitude. In this paper, we give exact expressions for the nonlinear complex viscosity and the corresponding nonlinear complex normal stress coefficients, for the Oldroyd 8-constant framework for oscillatory shear sweeps. We choose the Oldroyd 8-constant framework for its rich diversity of popular special cases (we list 18 of these). We evaluate the Fourier integrals of our previous exact solution to get exact expressions for the real and imaginary parts of the complex viscosity, and for the complex normal stress coefficients, as functions of both test frequency and shear rate amplitude. We explore the role of infinite shear rate viscosity on strain rate sweep responses for the special case of the corotational Jeffreys fluid. We find that raising η∞ raises the real part of the complex viscosity and lowers the imaginary. In our worked examples, we thus first use the corotational Jeffreys fluid, and then, for greater accuracy, we use the Johnson-Segalman fluid, to describe the strain rate sweep response of molten atactic polystyrene. For our comparisons with data, we use the Spriggs relations to generalize the Oldroyd 8-constant framework to multimode. Our generalization yields unequivocally, a longest fluid relaxation time, used to assign Weissenberg and Deborah numbers to each oscillatory shear flow experiment. We then locate each experiment in the Pipkin space.

Are physical activity interventions for healthy inactive adults effective in promoting behavior change and maintenance, and which behavior change techniques are effective? A systematic review and meta-analysis.

PubMed

Howlett, Neil; Trivedi, Daksha; Troop, Nicholas A; Chater, Angel Marie

2018-02-28

Physical inactivity and sedentary behavior relate to poor health outcomes independently. Healthy inactive adults are a key target population for prevention. This systematic review and meta-analysis aimed to evaluate the effectiveness of physical activity and/or sedentary behavior interventions, measured postintervention (behavior change) and at follow-up (behavior change maintenance), to identify behavior change techniques (BCT) within, and report on fidelity. Included studies were randomized controlled trials, targeting healthy inactive adults, aiming to change physical activity and/or sedentary behavior, with a minimum postintervention follow-up of 6 months, using 16 databases from 1990. Two reviewers independently coded risk of bias, the "Template for Intervention Description and Replication" (TIDieR) checklist, and BCTs. Twenty-six studies were included; 16 pooled for meta-analysis. Physical activity interventions were effective at changing behavior (d = 0.32, 95% confidence intervals = 0.16-0.48, n = 2,346) and maintaining behavior change after 6 months or more (d = 0.21, 95% confidence intervals = 0.12-0.30, n = 2,190). Sedentary behavior interventions (n = 2) were not effective. At postintervention, physical activity intervention effectiveness was associated with the BCTs "Biofeedback," "Demonstration of the behavior," "Behavior practice/rehearsal," and "Graded tasks." At follow-up, effectiveness was associated with using "Action planning," "Instruction on how to perform the behavior," "Prompts/cues," "Behavior practice/rehearsal," "Graded tasks," and "Self-reward." Fidelity was only documented in one study. Good evidence was found for behavior change maintenance effects in healthy inactive adults, and underlying BCTs. This review provides translational evidence to improve research, intervention design, and service delivery in physical activity interventions, while highlighting the lack of fidelity measurement.

Characterizing pedagogical practices of university physics students in informal learning environments

NASA Astrophysics Data System (ADS)

Hinko, Kathleen A.; Madigan, Peter; Miller, Eric; Finkelstein, Noah D.

2016-06-01

[This paper is part of the Focused Collection on Preparing and Supporting University Physics Educators.] University educators (UEs) have a long history of teaching physics not only in formal classroom settings but also in informal outreach environments. The pedagogical practices of UEs in informal physics teaching have not been widely studied, and they may provide insight into formal practices and preparation. We investigate the interactions between UEs and children in an afterschool physics program facilitated by university physics students from the University of Colorado Boulder. In this program, physics undergraduates, graduate students, and postdoctoral researchers work with K-8 children on hands-on physics activities on a weekly basis over the course of a semester. We use an activity theoretic framework as a tool to examine situational aspects of individuals' behavior in the complex structure of the afterschool program. Using this framework, we analyze video of UE-child interactions and identify three main pedagogical modalities that UEs display during activities: instruction, consultation, and participation modes. These modes are characterized by certain language, physical location, and objectives that establish differences in UE-child roles and division of labor. Based on this analysis, we discuss implications for promoting pedagogical strategies through purposeful curriculum development and university educator preparation.

Physical Outdoor Activity versus Indoor Activity: Their Influence on Environmental Behaviors.

PubMed

Fang, Wei-Ta; Ng, Eric; Chang, Mei-Chuan

2017-07-17

There are strong evidences linking physical outdoor activity and health benefits; however, little is known about the impact on environmental behaviors. Thus, this study aims to close this gap by investigating the influence of physical outdoor activity on environmental behaviors. A total of 416 surveys were distributed to students in eight public primary schools located near the Hsinchu Science and Industrial Park in Taiwan. Findings from the analysis revealed that subjective norms had a more influential effect on environmental behaviors for participants who engaged in physical activity at outdoor parks. In contrast, descriptive norms had a direct predictive impact on environmental behaviors for participants whose main physical activity venue was at the indoor after-school centers. Research results also highlighted attitude as the strongest predictive variable influence on environmental behaviors for children who engaged in physical indoor and outdoor activities.

Quantum Speedup for Active Learning Agents

NASA Astrophysics Data System (ADS)

Paparo, Giuseppe Davide; Dunjko, Vedran; Makmal, Adi; Martin-Delgado, Miguel Angel; Briegel, Hans J.

2014-07-01

Can quantum mechanics help us build intelligent learning agents? A defining signature of intelligent behavior is the capacity to learn from experience. However, a major bottleneck for agents to learn in real-life situations is the size and complexity of the corresponding task environment. Even in a moderately realistic environment, it may simply take too long to rationally respond to a given situation. If the environment is impatient, allowing only a certain time for a response, an agent may then be unable to cope with the situation and to learn at all. Here, we show that quantum physics can help and provide a quadratic speedup for active learning as a genuine problem of artificial intelligence. This result will be particularly relevant for applications involving complex task environments.

Avalanches and plastic flow in crystal plasticity: an overview

NASA Astrophysics Data System (ADS)

Papanikolaou, Stefanos; Cui, Yinan; Ghoniem, Nasr

2018-01-01

Crystal plasticity is mediated through dislocations, which form knotted configurations in a complex energy landscape. Once they disentangle and move, they may also be impeded by permanent obstacles with finite energy barriers or frustrating long-range interactions. The outcome of such complexity is the emergence of dislocation avalanches as the basic mechanism of plastic flow in solids at the nanoscale. While the deformation behavior of bulk materials appears smooth, a predictive model should clearly be based upon the character of these dislocation avalanches and their associated strain bursts. We provide here a comprehensive overview of experimental observations, theoretical models and computational approaches that have been developed to unravel the multiple aspects of dislocation avalanche physics and the phenomena leading to strain bursts in crystal plasticity.

Reduction of a linear complex model for respiratory system during Airflow Interruption.

PubMed

Jablonski, Ireneusz; Mroczka, Janusz

2010-01-01

The paper presents methodology of a complex model reduction to its simpler version - an identifiable inverse model. Its main tool is a numerical procedure of sensitivity analysis (structural and parametric) applied to the forward linear equivalent designed for the conditions of interrupter experiment. Final result - the reduced analog for the interrupter technique is especially worth of notice as it fills a major gap in occlusional measurements, which typically use simple, one- or two-element physical representations. Proposed electrical reduced circuit, being structural combination of resistive, inertial and elastic properties, can be perceived as a candidate for reliable reconstruction and quantification (in the time and frequency domain) of dynamical behavior of the respiratory system in response to a quasi-step excitation by valve closure.

Physical Therapists' Role in Health Promotion as Perceived by the Patient: Descriptive Survey.

PubMed

Black, Beth; Ingman, MarySue; Janes, Jamie

2016-10-01

The importance of health professionals discussing health behaviors with patients is emphasized in Healthy People 2020, the national health objectives established by the US Department of Health and Human Services. Many physical therapists do not routinely discuss health behaviors with their patients. One reason may be uncertainty about how these discussions might be perceived by patients. The primary purpose of this study was to determine patients' opinions regarding physical therapists discussing the topics of physical activity, smoking, fruit and vegetable consumption, and maintaining a healthy weight during clinical visits. A secondary purpose was to determine whether patients believe that physical therapists should be role models for these behaviors. This was a descriptive cross-sectional survey. Patients were surveyed at 8 outpatient clinics in Michigan and Minnesota. A written questionnaire collected information about the participants' health behaviors, their opinions about physical therapists discussing their health behaviors during clinical visits, and their opinions about physical therapists role-modeling healthy behaviors. The survey response rate was 45.6%. A total of 230 patients participated. Most participants agreed that physical therapists should speak to them about physical activity (91.3%), maintaining a healthy weight (73%), and abstaining from smoking (51.3%). Fewer participants agreed that physical therapists should advise them about fruit and vegetable consumption (32.1%). The majority of participants agreed that physical therapists should be role models for engaging in regular physical activity (83.4%), maintaining a healthy weight (71.7%), and abstaining from smoking (63.9%). Limitations of this study include the potential for response bias and limited generalizability. Most participants believed it is appropriate for physical therapists to speak with them about and be role models for the behaviors of physical activity, maintaining a healthy weight, and abstaining from smoking. Physical therapists have the opportunity to support the goals of Healthy People 2020 by discussing health behaviors with their patients. © 2016 American Physical Therapy Association.

A Meta-Analytic Review of the Theories of Reasoned Action and Planned Behavior in Physical Activity: Predictive Validity and the Contribution of Additional Variables.

ERIC Educational Resources Information Center

Hagger, Martin S.; Chatzisarantis, Nikos L. D.; Biddle, Stuart J. H.

2002-01-01

Examined relations between behavior, intentions, attitudes, subjective norms, perceived behavioral control, self-efficacy, and past behaviors using the Theories of Reasoned Action (TRA) and Planned Behavior (TPB) in physical activity. This quantitative integration of the physical activity literature supported the major relationships of the…

Sherwood Washburn's New physical anthropology: rejecting the "religion of taxonomy".

PubMed

Mikels-Carrasco, Jessica

2012-01-01

Many physical anthropologists and nearly all of those studying primatology today can trace their academic genealogy to Sherwood Larned Washburn. His New physical anthropology, fully articulated in a 1951 paper, proposed that the study of hominid evolution must link understandings of form, function, and behavior along with the environment in order most accurately to reconstruct the evolution of our ancestors. This shift of concentration from strictly analyzing fossil remains to what Washburn termed adaptive complexes challenged not only Washburn's predecessors, but also led Washburn to critique the very system of academia within which he worked. Collaboration across multiple disciplines, linking the four fields of anthropology in order to understand humans and application of our understandings of human evolution to the betterment of society, are the hallmarks of Washburnian anthropology. In this paper I will explore how Washburn's New physical anthropology led him to not only change the research direction in physical anthropology, but also to challenge the academia within which he worked. I will conclude by reflecting on the prospects of continuing to practice Washburnian Anthropology.

Successful Aging: Advancing the Science of Physical Independence in Older Adults

PubMed Central

Anton, Stephen D.; Woods, Adam J.; Ashizawa, Tetso; Barb, Diana; Buford, Thomas W.; Carter, Christy S.; Clark, David J.; Cohen, Ronald A.; Corbett, Duane B.; Cruz-Almeida, Yenisel; Dotson, Vonetta; Ebner, Natalie; Efron, Philip A.; Fillingim, Roger B.; Foster, Thomas C.; Gundermann, David M.; Joseph, Anna-Maria; Karabetian, Christy; Leeuwenburgh, Christiaan; Manini, Todd M.; Marsiske, Michael; Mankowski, Robert T.; Mutchie, Heather L.; Perri, Michael G.; Ranka, Sanjay; Rashidi, Parisa; Sandesara, Bhanuprasad; Scarpace, Philip J.; Sibille, Kimberly T.; Solberg, Laurence M.; Someya, Shinichi; Uphold, Connie; Wohlgemuth, Stephanie; Wu, Samuel Shangwu; Pahor, Marco

2015-01-01

The concept of ‘Successful Aging’ has long intrigued the scientific community. Despite this long-standing interest, a consensus definition has proven to be a difficult task, due to the inherent challenge involved in defining such a complex, multi-dimensional phenomenon. The lack of a clear set of defining characteristics for the construct of successful aging has made comparison of findings across studies difficult and has limited advances in aging research. The domain in which consensus on markers of successful aging is furthest developed is the domain of physical functioning. For example, walking speed appears to be an excellent surrogate marker of overall health and predicts the maintenance of physical independence, a cornerstone of successful aging. The purpose of the present article is to provide an overview and discussion of specific health conditions, behavioral factors, and biological mechanisms that mark declining mobility and physical function and promising interventions to counter these effects. With life expectancy continuing to increase in the United States and developed countries throughout the world, there is an increasing public health focus on the maintenance of physical independence among all older adults. PMID:26462882

Focused Research Group in Correlated Electron and Complex Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ziqiang

While the remarkable physical properties of correlated and complex electronic materials hold great promise for technological applications, one of the key values of the research in this field is its profound impact on fundamental physics. The transition metal oxides, pnictides, and chalcogenides play a key role and occupy an especially important place in this field. The basic reason is that the outer shell of transition metals contains the atomic d-orbitals that have small spatial extent, but not too small to behave as localized orbtials. These d-electrons therefore have a small wave function overlap in a solid, e.g. in an octahedralmore » environment, and form energy bands that are relatively narrow and on the scale of the short-range intra-atomic Coulomb repulsion (Hubbard U). In this intermediate correlation regime lies the challenge of the many-body physics responsible for new and unconventional physical properties. The study of correlated electron and complex materials represents both the challenge and the vitality of condensed matter and materials physics and often demands close collaborations among theoretical and experimental groups with complementary techniques. Our team has a track record and a long-term research goal of studying the unusual complexities and emergent behaviors in the charge, spin, and orbital sectors of the transition metal compounds in order to gain basic knowledge of the quantum electronic states of matter. During the funding period of this grant, the team continued their close collaborations between theory, angle-resolved photoemission spectroscopy, and scanning tunneling microscopy and made significant progress and contributions to the field of iron-based superconductors, copper-oxide high-temperature superconductors, triangular lattice transition metal oxide cobaltates, strontium ruthenates, spin orbital coupled iridates, as well as topological insulators and other topological quantum states of matter. These results include both new discoveries and the resolution to outstanding and unresolved issues. It should be emphasized that the DOE funding provided the crucial support for the close and meaningful collaborations of the focused research group that go far beyond simply putting the research papers from each group together. Indeed, the majority of the publications involved multiple PIs and collaborations between theory and experiments.« less

Revisiting the Quantum Brain Hypothesis: Toward Quantum (Neuro)biology?

PubMed Central

Jedlicka, Peter

2017-01-01

The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system’s behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics. PMID:29163041

Revisiting the Quantum Brain Hypothesis: Toward Quantum (Neuro)biology?

PubMed

Jedlicka, Peter

2017-01-01

The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system's behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics.

Physical Education: The Behavior Modification Approach. The Curriculum Series.

ERIC Educational Resources Information Center

Presbie, Robert J.; Brown, Paul L.

Behavior modification is discussed as a new approach to teaching and curriculum implementation in physical education. It is suggested that behavior modification offers physical education several advantages: (1) extensive research findings of various kinds directly applicable to the work of the physical education teacher; (2) a set of behavioral…

Social Goals in Urban Physical Education: Relationships with Effort and Disruptive Behavior

ERIC Educational Resources Information Center

Garn, Alex; McCaughtry, Nate; Shen, Bo; Martin, Jeffrey J.; Fahlman, Mariane M.

2011-01-01

This study investigated the relationships among four distinct types of social goals, effort, and disruptive behavior in urban physical education. Social responsibility, affiliation, recognition, status goals, along with effort and disruptive behavior in physical education were reported by high school physical education students (N = 314) from…

Tips for Dealing with Behavior Management Issues

ERIC Educational Resources Information Center

Bechtel, Pamela A.; Stevens, Lisa A.; Brett, Christine E. W.

2012-01-01

The increased diversity of today's students included in P-12 physical education classes creates new challenges in behavior management for physical education teachers. Currently more students with identified at-risk behaviors, as well as more students with physical or mental disabilities, are placed in general physical education classes. This…

Learning from physics-based earthquake simulators: a minimal approach

NASA Astrophysics Data System (ADS)

Artale Harris, Pietro; Marzocchi, Warner; Melini, Daniele

2017-04-01

Physics-based earthquake simulators are aimed to generate synthetic seismic catalogs of arbitrary length, accounting for fault interaction, elastic rebound, realistic fault networks, and some simple earthquake nucleation process like rate and state friction. Through comparison of synthetic and real catalogs seismologists can get insights on the earthquake occurrence process. Moreover earthquake simulators can be used to to infer some aspects of the statistical behavior of earthquakes within the simulated region, by analyzing timescales not accessible through observations. The develoment of earthquake simulators is commonly led by the approach "the more physics, the better", pushing seismologists to go towards simulators more earth-like. However, despite the immediate attractiveness, we argue that this kind of approach makes more and more difficult to understand which physical parameters are really relevant to describe the features of the seismic catalog at which we are interested. For this reason, here we take an opposite minimal approach and analyze the behavior of a purposely simple earthquake simulator applied to a set of California faults. The idea is that a simple model may be more informative than a complex one for some specific scientific objectives, because it is more understandable. The model has three main components: the first one is a realistic tectonic setting, i.e., a fault dataset of California; the other two components are quantitative laws for earthquake generation on each single fault, and the Coulomb Failure Function for modeling fault interaction. The final goal of this work is twofold. On one hand, we aim to identify the minimum set of physical ingredients that can satisfactorily reproduce the features of the real seismic catalog, such as short-term seismic cluster, and to investigate on the hypothetical long-term behavior, and faults synchronization. On the other hand, we want to investigate the limits of predictability of the model itself.

Individual, Social, and Environmental Correlates of Active Transportation Patterns in French Women.

PubMed

Perchoux, Camille; Enaux, Christophe; Oppert, Jean-Michel; Menai, Mehdi; Charreire, Hélène; Salze, Paul; Weber, Christiane; Hercberg, Serge; Feuillet, Thierry; Hess, Franck; Roda, Célina; Simon, Chantal; Nazare, Julie-Anne

2017-01-01

The objectives were (1) to define physical activity (PA) and sedentary behaviors (SB) patterns in daily life contexts (work, leisure, and transportation) in French working women from NutriNet-Santé web-cohort and (2) to identify pattern(s) of active transportation and their individual, social, and environmental correlates. 23,432 participants completed two questionnaires to evaluate PA and SB in daily life contexts and individual representations of residential neighborhood and transportation modes. Hierarchical cluster analysis was performed which identified 6 distinct movement behavior patterns: (i) active occupation, high sedentary leisure, (ii) sedentary occupation, low leisure, (iii) sedentary transportation, (iv) sedentary occupation and leisure, (v) active transportation, and (vi) active leisure. Multinomial logistic regressions were performed to identify correlates of the "active transportation" cluster. The perceived environmental characteristics positively associated with "active transportation" included "high availability of destinations around home," "presence of bicycle paths," and "low traffic." A "positive image of walking/cycling," the "individual feeling of being physically active," and a "high use of active transport modes by relatives/friends" were positively related to "active transportation," identified as a unique pattern regarding individual and environmental correlates. Identification of PA and SB context-specific patterns will help to understand movement behaviors' complexity and to design interventions to promote active transportation in specific subgroups.

Competition of density waves and quantum multicritical behavior in Dirac materials from functional renormalization

NASA Astrophysics Data System (ADS)

Classen, Laura; Herbut, Igor F.; Janssen, Lukas; Scherer, Michael M.

2016-03-01

We study the competition of spin- and charge-density waves and their quantum multicritical behavior for the semimetal-insulator transitions of low-dimensional Dirac fermions. Employing the effective Gross-Neveu-Yukawa theory with two order parameters as a model for graphene and a growing number of other two-dimensional Dirac materials allows us to describe the physics near the multicritical point at which the semimetallic and the spin- and charge-density-wave phases meet. With the help of a functional renormalization group approach, we are able to reveal a complex structure of fixed points, the stability properties of which decisively depend on the number of Dirac fermions Nf. We give estimates for the critical exponents and observe crucial quantitative corrections as compared to the previous first-order ɛ expansion. For small Nf, the universal behavior near the multicritical point is determined by the chiral Heisenberg universality class supplemented by a decoupled, purely bosonic, Ising sector. At large Nf, a novel fixed point with nontrivial couplings between all sectors becomes stable. At intermediate Nf, including the graphene case (Nf=2 ), no stable and physically admissible fixed point exists. Graphene's phase diagram in the vicinity of the intersection between the semimetal, antiferromagnetic, and staggered density phases should consequently be governed by a triple point exhibiting first-order transitions.

An exercise trial for wheelchair users: Project Workout on Wheels

PubMed Central

Froehlich-Grobe, Katherine; Aaronson, Lauren S.; Washburn, Richard A.; Little, Todd D.; Lee, Jaehoon; Nary, Dorothy E.; VanSciver, Angela; Nesbitt, Jill; Norman, Sarah E.

2011-01-01

There is growing interest in promoting health for people with disabilities, yet evidence regarding community-based interventions is sparse. This paper describes the design details of a randomized controlled trial (RCT) that will test the effectiveness of a multi-component behaviorally-based, intervention to promote exercise adoption (over 6 months) and maintenance (up to one year) among wheelchair users and includes descriptive data on participant characteristics at baseline. Participants were randomly assigned to either a staff-supported intervention group or a self-guided comparison group. The primary study aim is to assess the effectiveness of the multi-component behaviorally-based intervention for promoting physical activity adoption and maintenance. The RCT will also assess the physical and psychosocial effects of the intervention and the complex interplay of factors that influence the effectiveness of the intervention. Therefore, the primary outcome derives from participant reports of weekly exercise (type, frequency, duration) over 52 weeks. Secondary outcomes collected on four occasions (baseline, 3 months, 6 months, 12 months) included physiological outcomes (VO2 peak, strength), disability-related outcomes (pain, fatigue, participation), and psychosocial outcomes (exercise self-efficacy, exercise barriers, quality of life, depression, mood). This study will provide evidence regarding the effectiveness of a multi-component behaviorally-based intervention for promoting exercise adoption among people with mobility impairments that necessitate wheelchair use. PMID:22101206

Titan's Complex Chemistry: Insights from the Lab

NASA Astrophysics Data System (ADS)

Horst, Sarah

2018-06-01

The Cassini-Huygens mission revealed Titan to be a complex world with physical processes reminiscent of other terrestrial planets, but chemistry that is unlike anywhere else in the Solar System. Titan's complex atmospheric chemistry converts N2 and CH4 into numerous, abundant organic molecules ranging from relatively simple hydrocarbons to ions with mass to charge ratios up to 10,000 amu/q. The molecules eventually settle to the surface where they can participate in and be modified by geological processes such as aeolian and fluvial erosion or undergo subsequent chemistry in Titan's lakes and seas or impact craters and potential cryovolcanic flows. From the processes leading to massive ion formation in the atmosphere to the behavior of saltating organic sands on the surface, laboratory experiments are playing a pivotal role in understanding Titan and expanding our understanding of planetary processes into new, exciting phase space.

Retrieving the aerosol complex refractive index using PyMieScatt: A Mie computational package with visualization capabilities

NASA Astrophysics Data System (ADS)

Sumlin, Benjamin J.; Heinson, William R.; Chakrabarty, Rajan K.

2018-01-01

The complex refractive index m = n + ik of a particle is an intrinsic property which cannot be directly measured; it must be inferred from its extrinsic properties such as the scattering and absorption cross-sections. Bohren and Huffman called this approach "describing the dragon from its tracks", since the inversion of Lorenz-Mie theory equations is intractable without the use of computers. This article describes PyMieScatt, an open-source module for Python that contains functionality for solving the inverse problem for complex m using extensive optical and physical properties as input, and calculating regions where valid solutions may exist within the error bounds of laboratory measurements. Additionally, the module has comprehensive capabilities for studying homogeneous and coated single spheres, as well as ensembles of homogeneous spheres with user-defined size distributions, making it a complete tool for studying the optical behavior of spherical particles.

Accuracy and Calibration of High Explosive Thermodynamic Equations of State

NASA Astrophysics Data System (ADS)

Baker, Ernest L.; Capellos, Christos; Stiel, Leonard I.; Pincay, Jack

2010-10-01

The Jones-Wilkins-Lee-Baker (JWLB) equation of state (EOS) was developed to more accurately describe overdriven detonation while maintaining an accurate description of high explosive products expansion work output. The increased mathematical complexity of the JWLB high explosive equations of state provides increased accuracy for practical problems of interest. Increased numbers of parameters are often justified based on improved physics descriptions but can also mean increased calibration complexity. A generalized extent of aluminum reaction Jones-Wilkins-Lee (JWL)-based EOS was developed in order to more accurately describe the observed behavior of aluminized explosives detonation products expansion. A calibration method was developed to describe the unreacted, partially reacted, and completely reacted explosive using nonlinear optimization. A reasonable calibration of a generalized extent of aluminum reaction JWLB EOS as a function of aluminum reaction fraction has not yet been achieved due to the increased mathematical complexity of the JWLB form.

Nonparametric estimation of stochastic differential equations with sparse Gaussian processes.

PubMed

García, Constantino A; Otero, Abraham; Félix, Paulo; Presedo, Jesús; Márquez, David G

2017-08-01

The application of stochastic differential equations (SDEs) to the analysis of temporal data has attracted increasing attention, due to their ability to describe complex dynamics with physically interpretable equations. In this paper, we introduce a nonparametric method for estimating the drift and diffusion terms of SDEs from a densely observed discrete time series. The use of Gaussian processes as priors permits working directly in a function-space view and thus the inference takes place directly in this space. To cope with the computational complexity that requires the use of Gaussian processes, a sparse Gaussian process approximation is provided. This approximation permits the efficient computation of predictions for the drift and diffusion terms by using a distribution over a small subset of pseudosamples. The proposed method has been validated using both simulated data and real data from economy and paleoclimatology. The application of the method to real data demonstrates its ability to capture the behavior of complex systems.

Suicide in older adults: current perspectives

PubMed Central

Conejero, Ismael; Olié, Emilie; Courtet, Philippe; Calati, Raffaella

2018-01-01

Suicidal behavior in older adults (65 years old and over) is a major public health issue in many countries. Suicide rates increase during the life course and are as high as 48.7/100,000 among older white men in the USA. Specific health conditions and stress factors increase the complexity of the explanatory model for suicide in older adults. A PubMed literature search was performed to identify most recent and representative studies on suicide risk factors in older adults. The aim of our narrative review was to provide a critical evaluation of recent findings concerning specific risk factors for suicidal thoughts and behaviors among older people: psychiatric and neurocognitive disorders, social exclusion, bereavement, cognitive impairment, decision making and cognitive inhibition, physical illnesses, and physical and psychological pain. We also aimed to approach the problem of euthanasia or physician-assisted suicide in older adults. Our main findings emphasize the need to integrate specific stress factors, such as feelings of social disconnectedness, neurocognitive impairment or decision making, as well as chronic physical illnesses and disability in suicide models and in suicide prevention programs in older adults. Furthermore, the chronic care model should be adapted for the treatment of older people with long-term conditions in order to improve the treatment of depressive disorders and the prevention of suicidal thoughts and acts. PMID:29719381

Association of Physical Activity and Sedentary Behavior With Psychological Well-Being Among Japanese Children: A Two-Year Longitudinal Study.

PubMed

Ishii, Kaori; Shibata, Ai; Adachi, Minoru; Oka, Koichiro

2016-10-01

Data on the effect of increased or decreased physical activity on children's psychological status are scarce, and effect sizes are small. This study conducted two-year longitudinal research to identify associations between physical activity, sedentary behavior, and psychological well-being in Japanese school children through a mail survey completed by 292 children aged 6-12 years. Data on sociodemographics, physical activity, sedentary behavior on weekdays and the weekend, and psychometrics (self-efficacy, anxiety, and behavioral/emotional problems) were collected using a self-reported questionnaire. A logistic regression analysis was performed, calculating odds ratios for physical activity, psychometrics, and baseline age and physical activity and sedentary behavior changes. For boys, a negative association was found between increased physical activity outside school and maintained or improved self-efficacy as opposed to a positive association in girls. Increased sedentary behavior on weekdays and long periods of sedentary behavior on weekends were associated with maintained or improved behavioral/emotional problems in girls only. This two-year longitudinal study is the first of its kind conducted in Japan. Although effect sizes were small, these results may nevertheless assist in intervention development to promote psychological well-being. © The Author(s) 2016.

Maternal and paternal physical abuse: Unique and joint associations with child behavioral problems.

PubMed

Cui, Naixue; Deatrick, Janet A; Liu, Jianghong

2018-02-01

Although there is a substantial amount of literature documenting the relationship between child abuse and behavioral problems in China, there is, on the other hand, a limited number of studies on the joint and unique associations of maternal and paternal physical abuse with child behaviors within the Chinese context. The present study, using the family systems theory as the theoretical framework, aims to examine these joint and the unique associations of maternal and paternal physical abuse with externalizing and internalizing behaviors among a community sample of Chinese children. A total of 296 children (54.7% boys, mean age 12.31±0.56years) from two-parent families participated in the study, and they reported their physical abuse experience by their mother and father in the previous year using the Chinese version of the Parent-Child Conflict Tactics Scale. Participants, using the Youth Self Report, reported personal externalizing and internalizing behaviors, and, similarly, their mothers, using the Child Behavior Checklist, assessed children's externalizing and internalizing behaviors. Linear mixed effect models with random intercept and slope were used to examine the joint and unique associations of maternal and paternal physical abuse with child externalizing and internalizing behaviors. Results revealed that physically abused children were more likely to be simultaneously abused by both mothers and fathers. Furthermore, when compared with their non-abused counterparts, children with physical abuse that was carried out solely by mothers (externalizing behaviors: β=6.71, 95% CI=2.45-10.98, p<0.01; internalizing behaviors: β=4.52, 95% CI=0.37-8.66, p<0.05) or by both mothers and fathers (externalizing behaviors: β=4.52, 95% CI=1.80-7.24, p<0.001; internalizing behaviors: β=2.98, 95% CI=0.34-5.61, p<0.05) reported more externalizing and internalizing behaviors. Externalizing and internalizing behaviors of children who were physically abused solely by fathers did not significantly differ from those of their non-abused counterparts, which may result from the small sample size. The present findings suggest that maternal physical abuse may have a dominant and unique association with child behaviors, regardless of whether paternal physical abuse occurs within the family. Implications for future research and practice within the Chinese context regarding the subject of child behaviors and parental abuse are discussed. Copyright © 2017. Published by Elsevier Ltd.

Dynamics and Collapse in a Power System Model with Voltage Variation: The Damping Effect.

PubMed

Ma, Jinpeng; Sun, Yong; Yuan, Xiaoming; Kurths, Jürgen; Zhan, Meng

2016-01-01

Complex nonlinear phenomena are investigated in a basic power system model of the single-machine-infinite-bus (SMIB) with a synchronous generator modeled by a classical third-order differential equation including both angle dynamics and voltage dynamics, the so-called flux decay equation. In contrast, for the second-order differential equation considering the angle dynamics only, it is the classical swing equation. Similarities and differences of the dynamics generated between the third-order model and the second-order one are studied. We mainly find that, for positive damping, these two models show quite similar behavior, namely, stable fixed point, stable limit cycle, and their coexistence for different parameters. However, for negative damping, the second-order system can only collapse, whereas for the third-order model, more complicated behavior may happen, such as stable fixed point, limit cycle, quasi-periodicity, and chaos. Interesting partial collapse phenomena for angle instability only and not for voltage instability are also found here, including collapse from quasi-periodicity and from chaos etc. These findings not only provide a basic physical picture for power system dynamics in the third-order model incorporating voltage dynamics, but also enable us a deeper understanding of the complex dynamical behavior and even leading to a design of oscillation damping in electric power systems.

Experimental and Numerical Investigation of Reduced Gravity Fluid Slosh Dynamics for the Characterization of Cryogenic Launch and Space Vehicle Propellants

NASA Technical Reports Server (NTRS)

Walls, Laurie K.; Kirk, Daniel; deLuis, Kavier; Haberbusch, Mark S.

2011-01-01

As space programs increasingly investigate various options for long duration space missions the accurate prediction of propellant behavior over long periods of time in microgravity environment has become increasingly imperative. This has driven the development of a detailed, physics-based understanding of slosh behavior of cryogenic propellants over a range of conditions and environments that are relevant for rocket and space storage applications. Recent advancements in computational fluid dynamics (CFD) models and hardware capabilities have enabled the modeling of complex fluid behavior in microgravity environment. Historically, launch vehicles with moderate duration upper stage coast periods have contained very limited instrumentation to quantify propellant stratification and boil-off in these environments, thus the ability to benchmark these complex computational models is of great consequence. To benchmark enhanced CFD models, recent work focuses on establishing an extensive experimental database of liquid slosh under a wide range of relevant conditions. In addition, a mass gauging system specifically designed to provide high fidelity measurements for both liquid stratification and liquid/ullage position in a micro-gravity environment has been developed. This pUblication will summarize the various experimental programs established to produce this comprehensive database and unique flight measurement techniques.

Liquid crystalline phase behavior of protein fibers in water: experiments versus theory.

PubMed

Jung, Jin-Mi; Mezzenga, Raffaele

2010-01-05

We have developed a new method allowing the study of the thermodynamic phase behavior of mesoscopic colloidal systems consisting of amyloid protein fibers in water, obtained by heat denaturation and aggregation of beta-lactoglobulin, a dairy protein. The fibers have a cross section of about 5.2 nm and two groups of polydisperse contour lengths: (i) long fibers of 1-20 microm, showing semiflexible behavior, and (ii) short rods of 100-200 nm long, obtained by cutting the long fibers via high-pressure homogenization. At pH 2 without salt, these fibers are highly charged and stable in water. We have studied the isotropic-nematic phase transition for both systems and compared our results with the theoretical values predicted by Onsager's theory. The experimentally measured isotropic-nematic phase transition was found to occur at 0.4% and at 3% for the long and short fibers, respectively. For both systems, this phase transition occurs at concentrations more than 1 order of magnitude lower than what is expected based on Onsager's theory. Moreover, at low enough pH, no intermediate biphasic region was observed between the isotropic phase and the nematic phase. The phase diagrams of both systems (pH vs concentration) showed similar, yet complex and rich, phase behavior. We discuss the possible physical fundamentals ruling the phase diagram as well as the discrepancy we observe for the isotropic-nematic phase transition between our experimental results and the predicted theoretical results. Our work highlights that systems formed by water-amyloid protein fibers are way too complex to be understood based solely on Onsager's theories. Experimental results are revisited in terms of the Flory's theory (1956) for suspensions of rods, which allows accounting for rod-solvent hydrophobic interactions. This theoretical approach allows explaining, on a semiquantitative basis, most of the discrepancies observed between the experimental results and Onsager's predictions. The sources of protein fibers complex colloidal behavior are analyzed and discussed at length.

Autonomous Motivation Predicts 7-Day Physical Activity in Hong Kong Students.

PubMed

Ha, Amy S; Ng, Johan Y Y

2015-07-01

Autonomous motivation predicts positive health behaviors such as physical activity. However, few studies have examined the relation between motivational regulations and objectively measured physical activity and sedentary behaviors. Thus, we investigated whether different motivational regulations (autonomous motivation, controlled motivation, and amotivation) predicted 7-day physical activity, sedentary behaviors, and health-related quality of life (HRQoL) of students. A total of 115 students (mean age = 11.6 years, 55.7% female) self-reported their motivational regulations and health-related quality of life. Physical activity and sedentary behaviors were measured using accelerometers for seven days. Using multilevel modeling, we found that autonomous motivation predicted higher levels of moderate-to-vigorous physical activity, less sedentary behaviors, and better HRQoL. Controlled motivation and amotivation each only negatively predicted one facet of HRQoL. Results suggested that autonomous motivation could be an important predictor of physical activity behaviors in Hong Kong students. Promotion of this form of motivational regulation may also increase HRQoL. © 2015 The International Association of Applied Psychology.

Interest rate change and Omori dynamics in the Stock Market

NASA Astrophysics Data System (ADS)

Petersen, Alexander; Wang, Fengzhong; Havlin, Shlomo; Stanley, H. Eugene

2009-03-01

I present the behavior of U.S. markets on the day of U.S. Federal Open Market Commission (FOMC) meetings from the perspective of Statistical Physics. The announcement of key U.S. Federal Reserve rate changes causes a small financial shock, where the dynamics before and after the announcement can be described by an Omori law. We find that markets respond sharply to the news in a complex way reminiscent of physical earthquakes described by the Omori law, which describes the power-law relaxation of aftershocks following a singular perturbation. We find Omori laws in both the volatility of the price (also known as the absolute returns) and the volume traded, using 1-minute resolution financial time series. These results suggest that the perturbative response of the stock market is the same for both financial news and financial crises. The intraday response can be measured by the Omori power-law exponent φ, which has opposite sign before and after the announcement. We estimate the magnitude of news by relating φ to the behavior of the U. S. Treasury Bill before and after FOMC announcements.

Towards 24/7 continuous heart rate monitoring.

PubMed

Tarniceriu, Adrian; Parak, Jakub; Renevey, Philippe; Nurmi, Marko; Bertschi, Mattia; Delgado-Gonzalo, Ricard; Korhonen, Ilkka

2016-08-01

Heart rate (HR) and HR variability (HRV) carry rich information about physical activity, mental and physical load, physiological status, and health of an individual. When combined with activity monitoring and personalized physiological modelling, HR/HRV monitoring may be used for monitoring of complex behaviors and impact of behaviors and external factors on the current physiological status of an individual. Optical HR monitoring (OHR) from wrist provides a comfortable and unobtrusive method for HR/HRV monitoring and is better adhered by users than traditional ECG electrodes or chest straps. However, OHR power consumption is significantly higher than that for ECG based methods due to the measurement principle based on optical illumination of the tissue. We developed an algorithmic approach to reduce power consumption of the OHR in 24/7 HR trending. We use continuous activity monitoring and a fast converging frequency domain algorithm to derive a reliable HR estimate in 7.1s (during outdoor sports, in average) to 10.0s (during daily life). The method allows >80% reduction in power consumption in 24/7 OHR monitoring when average HR monitoring is targeted, without significant reduction in tracking accuracy.

Evaluating Exercise as a Therapeutic Intervention for Methamphetamine Addiction-Like Behavior1

PubMed Central

Somkuwar, Sucharita S.; Staples, Miranda C.; Fannon, McKenzie J.; Ghofranian, Atoosa; Mandyam, Chitra D.

2015-01-01

Abstract The need for effective treatments for addiction and dependence to the illicit stimulant methamphetamine in primary care settings is increasing, yet no effective medications have been FDA approved to reduce dependence [1]. This is partially attributed to the complex and dynamic neurobiology underlying the various stages of addiction [2]. Therapeutic strategies to treat methamphetamine addiction, particularly the relapse stage of addiction, could revolutionize methamphetamine addiction treatment. In this context, preclinical studies demonstrate that voluntary exercise (sustained physical activity) could be used as an intervention to reduce methamphetamine addiction. Therefore, it appears that methamphetamine disrupts normal functioning in the brain and this disruption is prevented or reduced by engaging in exercise. This review discusses animal models of methamphetamine addiction and sustained physical activity and the interactions between exercise and methamphetamine behaviors. The review highlights how methamphetamine and exercise affect neuronal plasticity and neurotoxicity in the adult mammalian striatum, hippocampus, and prefrontal cortex, and presents the emerging mechanisms of exercise in attenuating intake and in preventing relapse to methamphetamine seeking in preclinical models of methamphetamine addiction. PMID:29765835

Differentiating physical discipline from abuse: Q findings from Chinese American mothers and pediatric nurses.

PubMed

Ho, Grace W K; Gross, Deborah A

2015-05-01

The perception and use of physical discipline (PD) is culture-based, and the differentiation between PD and abuse is subjective and complex. The purpose of this study was to understand how Chinese American mothers and one group of mandated reporters of child abuse (i.e. pediatric nurses) differentiate PD from abuse. Using Q-methodology, 3 viewpoints on PD and abuse differentiation were uncovered from a sample of 35 Chinese American mothers and 48 pediatric nurses. Although there was wide consensus on the most acceptable and most unacceptable parent discipline behaviors across the 3 views, the acceptability of punishments differed by their potential to inflict injury, pain, or incite fear and uncertainty. This was the first study to examine PD and abuse differentiation based on 5 definable domains of PD (i.e. specific behavior, intention, delivery, outcome, and pattern of use). Findings point to important nuances in how some mothers and nurses differentiate abuse from acceptable discipline, and the potential for using Q-methodology for exploring PD and abuse differentiations across diverse cultural, social, and professional groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sphere Drag and Heat Transfer

NASA Astrophysics Data System (ADS)

Duan, Zhipeng; He, Boshu; Duan, Yuanyuan

2015-07-01

Modelling fluid flows past a body is a general problem in science and engineering. Historical sphere drag and heat transfer data are critically examined. The appropriate drag coefficient is proposed to replace the inertia type definition proposed by Newton. It is found that the appropriate drag coefficient is a desirable dimensionless parameter to describe fluid flow physical behavior so that fluid flow problems can be solved in the simple and intuitive manner. The appropriate drag coefficient is presented graphically, and appears more general and reasonable to reflect the fluid flow physical behavior than the traditional century old drag coefficient diagram. Here we present drag and heat transfer experimental results which indicate that there exists a relationship in nature between the sphere drag and heat transfer. The role played by the heat flux has similar nature as the drag. The appropriate drag coefficient can be related to the Nusselt number. This finding opens new possibilities in predicting heat transfer characteristics by drag data. As heat transfer for flow over a body is inherently complex, the proposed simple means may provide an insight into the mechanism of heat transfer for flow past a body.

Sphere Drag and Heat Transfer.

PubMed

Duan, Zhipeng; He, Boshu; Duan, Yuanyuan

2015-07-20

Modelling fluid flows past a body is a general problem in science and engineering. Historical sphere drag and heat transfer data are critically examined. The appropriate drag coefficient is proposed to replace the inertia type definition proposed by Newton. It is found that the appropriate drag coefficient is a desirable dimensionless parameter to describe fluid flow physical behavior so that fluid flow problems can be solved in the simple and intuitive manner. The appropriate drag coefficient is presented graphically, and appears more general and reasonable to reflect the fluid flow physical behavior than the traditional century old drag coefficient diagram. Here we present drag and heat transfer experimental results which indicate that there exists a relationship in nature between the sphere drag and heat transfer. The role played by the heat flux has similar nature as the drag. The appropriate drag coefficient can be related to the Nusselt number. This finding opens new possibilities in predicting heat transfer characteristics by drag data. As heat transfer for flow over a body is inherently complex, the proposed simple means may provide an insight into the mechanism of heat transfer for flow past a body.

Physical Outdoor Activity versus Indoor Activity: Their Influence on Environmental Behaviors

PubMed Central

Fang, Wei-Ta; Ng, Eric; Chang, Mei-Chuan

2017-01-01

There are strong evidences linking physical outdoor activity and health benefits; however, little is known about the impact on environmental behaviors. Thus, this study aims to close this gap by investigating the influence of physical outdoor activity on environmental behaviors. A total of 416 surveys were distributed to students in eight public primary schools located near the Hsinchu Science and Industrial Park in Taiwan. Findings from the analysis revealed that subjective norms had a more influential effect on environmental behaviors for participants who engaged in physical activity at outdoor parks. In contrast, descriptive norms had a direct predictive impact on environmental behaviors for participants whose main physical activity venue was at the indoor after-school centers. Research results also highlighted attitude as the strongest predictive variable influence on environmental behaviors for children who engaged in physical indoor and outdoor activities. PMID:28714934

Physical Activity Behaviors of Students of a Rural Historically Black College

ERIC Educational Resources Information Center

Kemper, Karen A.; Welsh, Ralph S.

2010-01-01

Physical activity can have a positive impact on health disparities among African Americans. Objective: In this study, we assessed physical activity behaviors and correlates of students of a Historically Black College. Methods: In September 2004, an online survey and pedometers were used to measure physical activity behavior and correlates.…

Biomorphodynamics: Physical-biological feedbacks that shape landscapes

USGS Publications Warehouse

Murray, A.B.; Knaapen, M.A.F.; Tal, M.; Kirwan, M.L.

2008-01-01

Plants and animals affect morphological evolution in many environments. The term "ecogeomorphology" describes studies that address such effects. In this opinion article we use the term "biomorphodynamics" to characterize a subset of ecogeomorphologic studies: those that investigate not only the effects of organisms on physical processes and morphology but also how the biological processes depend on morphology and physical forcing. The two-way coupling precipitates feedbacks, leading to interesting modes of behavior, much like the coupling between flow/sediment transport and morphology leads to rich morphodynamic behaviors. Select examples illustrate how even the basic aspects of some systems cannot be understood without considering biomorphodynamic coupling. Prominent examples include the dynamic interactions between vegetation and flow/sediment transport that can determine river channel patterns and the multifaceted biomorphodynamic feedbacks shaping tidal marshes and channel networks. These examples suggest that the effects of morphology and physical processes on biology tend to operate over the timescale of the evolution of the morphological pattern. Thus, in field studies, which represent a snapshot in the pattern evolution, these effects are often not as obvious as the effects of biology on physical processes. However, numerical modeling indicates that the influences on biology from physical processes can play a key role in shaping landscapes and that even local and temporary vegetation disturbances can steer large-scale, long-term landscape evolution. The prevalence of biomorphodynamic research is burgeoning in recent years, driven by societal need and a confluence of complex systems-inspired modeling approaches in ecology and geomorphology. To make fundamental progress in understanding the dynamics of many landscapes, our community needs to increasingly learn to look for two-way, biomorphodynamic feedbacks and to collect new types of data to support the modeling of such emergent interactions. Copyright 2008 by the American Geophysical Union.

Acupuncture suppresses reinstatement of morphine-seeking behavior induced by a complex cue in rats.

PubMed

Lee, Bong Hyo; Lim, Sung Chul; Jeon, Hyeon Jeong; Kim, Jae Su; Lee, Yun Kyu; Lee, Hyun Jong; In, Sunghyun; Kim, Hee Young; Yoon, Seong Shoon; Yang, Chae Ha

2013-08-26

Morphine causes physical and psychological dependence for individuals after repeated-use. Above all, our previous study showed that acupuncture attenuated reinstatement of morphine-seeking behavior induced by pharmacological cue. In this study, we investigated whether acupuncture could suppress the reinstatement of morphine-seeking behavior induced by the combination of environmental and pharmacological cues and the possible neuronal involvement. Male Sprague-Dawley rats were trained to self-administer morphine (1.0 mg/kg) for 3 weeks. Following the withdrawal phase (7 days), the effects of acupuncture on reinstatement of morphine-seeking behavior were investigated. For the investigation of neuronal involvement, the GABAA receptor antagonist bicuculline and the GABAB receptor antagonist SCH 50911 were pre-treated. Morphine-seeking behavior induced by combination of re-exposure to the operant chamber and morphine injection was suppressed perfectly by acupuncture at SI5, but not at the control acupoint LI5 and this effect was blocked by pre-treatment with the GABA receptor antagonists. This study suggests that acupuncture at SI5 can be considered as a predominant therapy for the reinstatement of morphine-seeking behavior in humans. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Psychological, interpersonal, and clinical factors predicting time spent on physical activity among Mexican patients with hypertension

PubMed Central

Ybarra Sagarduy, José Luis; Camacho Mata, Dacia Yurima; Moral de la Rubia, José; Piña López, Julio Alfonso; Yunes Zárraga, José Luis Masud

2018-01-01

Background It is widely known that physical activity is the key to the optimal management and clinical control of hypertension. Purpose This research was conducted to identify factors that can predict the time spent on physical activity among Mexican adults with hypertension. Methods This cross-sectional study was conducted among 182 Mexican patients with hypertension, who completed a set of self-administered questionnaires related to personality, social support, and medical adherence and health care behaviors, body mass index, and time since the disease diagnosis. Several path analyses were performed in order to test the predictors of the study behavior. Results Lower tolerance to frustration, more tolerance to ambiguity, more effective social support, and less time since the disease diagnosis predicted more time spent on physical activity, accounting for 13.3% of the total variance. The final model shows a good fit to the sample data (pBS =0.235, χ2/gl =1.519, Jöreskog and Sörbom’s Goodness of Fit Index =0.987, adjusted modality =0.962, Bollen’s Incremental Fit Index =0.981, Bentler-Bonett Normed Fit Index =0.946, standardized root mean square residual =0.053). Conclusion The performance of physical activity in patients with hypertension depends on a complex set of interactions between personal, interpersonal, and clinical variables. Understanding how these factors interact might enhance the design of interdisciplinary intervention programs so that quality of life of patients with hypertension improves and they might be able to manage and control their disease well. PMID:29379276

Causal modeling of secondary science students' intentions to enroll in physics

NASA Astrophysics Data System (ADS)

Crawley, Frank E.; Black, Carolyn B.

The purpose of this study was to explore the utility of the theory of planned behavior model developed by social psychologists for understanding and predicting the behavioral intentions of secondary science students regarding enrolling in physics. In particular, the study used a three-stage causal model to investigate the links from external variables to behavioral, normative, and control beliefs; from beliefs to attitudes, subjective norm, and perceived behavioral control; and from attitudes, subjective norm, and perceived behavioral control to behavioral intentions. The causal modeling method was employed to verify the underlying causes of secondary science students' interest in enrolling physics as predicted in the theory of planned behavior. Data were collected from secondary science students (N = 264) residing in a central Texas city who were enrolled in earth science (8th grade), biology (9th grade), physical science (10th grade), or chemistry (11th grade) courses. Cause-and-effect relationships were analyzed using path analysis to test the direct effects of model variables specified in the theory of planned behavior. Results of this study indicated that students' intention to enroll in a high school physics course was determined by their attitude toward enrollment and their degree of perceived behavioral control. Attitude, subjective norm, and perceived behavioral control were, in turn, formed as a result of specific beliefs that students held about enrolling in physics. Grade level and career goals were found to be instrumental in shaping students' attitude. Immediate family members were identified as major referents in the social support system for enrolling in physics. Course and extracurricular conflicts and the fear of failure were shown to be the primary beliefs obstructing students' perception of control over physics enrollment. Specific recommendations are offered to researchers and practitioners for strengthening secondary school students' intentions to study physics.

Particle and surfactant interactions effected polar and dispersive components of interfacial energy in nanocolloids

NASA Astrophysics Data System (ADS)

Harikrishnan, A. R.; Das, Sarit K.; Agnihotri, Prabhat K.; Dhar, Purbarun

2017-08-01

We segregate and report experimentally for the first time the polar and dispersive interfacial energy components of complex nanocolloidal dispersions. In the present study, we introduce a novel inverse protocol for the classical Owens Wendt method to determine the constitutive polar and dispersive elements of surface tension in such multicomponent fluidic systems. The effect of nanoparticles alone and aqueous surfactants alone are studied independently to understand the role of the concentration of the dispersed phase in modulating the constitutive elements of surface energy in fluids. Surfactants are capable of altering the polar component, and the combined particle and surfactant nanodispersions are shown to be effective in modulating the polar and dispersive components of surface tension depending on the relative particle and surfactant concentrations as well as the morphological and electrostatic nature of the dispersed phases. We observe that the combined surfactant and particle colloid exhibits a similar behavior to that of the particle only case; however, the amount of modulation of the polar and dispersive constituents is found to be different from the particle alone case which brings to the forefront the mechanisms through which surfactants modulate interfacial energies in complex fluids. Accordingly, we are able to show that the observations can be merged into a form of quasi-universal trend in the trends of polar and dispersive components in spite of the non-universal character in the wetting behavior of the fluids. We analyze the different factors affecting the polar and dispersive interactions in such complex colloids, and the physics behind such complex interactions has been explained by appealing to the classical dispersion theories by London, Debye, and Keesom as well as by Derjaguin-Landau-Verwey-Overbeek theory. The findings shed light on the nature of wetting behavior of such complex fluids and help in predicting the wettability and the degree of interfacial interaction with a substrate in such multicomponent nanocolloidal systems.

Application of the transtheoretical model to sedentary behaviors and its association with physical activity status.

PubMed

Han, Ho; Pettee Gabriel, Kelley; Kohl, Harold Willis

2017-01-01

The Transtheoretical Model (TTM) is a successful framework for guiding behavior change programs for several health behaviors, yet its application to reduce of sedentary behavior has been neglected. In addition, no data exist regarding the association between determinants of sedentary behaviors based on the TTM and physical activity behavior. The purpose of this study was to investigate college students' stages of motivational readiness to avoid sedentary behaviors and relevant psychological determinants using newly developed TTM questionnaires and to identify the association between current physical activity and sedentary behaviors based on TTM constructs. Data were obtained from 225 college students enrolled in health education and physical education courses. Participants completed a package of questionnaires including validated TTM, physical activity and sitting time questionnaires. Participants also wore an accelerometer for seven consecutive days. MANOVAs were conducted to determine mean differences in psychological constructs across the TTM stages, and Chi-square tests and Spearman correlation were used to evaluate the associations between current physical activity and sedentary behavior. A majority of the participants were in the sedentary stages, and men and women differed in proportion of individuals in the stages (78.0% vs. 68.1%, respectively). The gender difference was also found in use of the processes of change. In general, the mean scores of the TTM constructs increased as the stages progressed. No significant associations were found between the TTM constructs for sedentary behavior and current physical activity levels (p>0.05). A high proportion of college students were in sedentary stages regardless of physical activity levels, but different distributions in men and women. Participants in earlier stages were less likely to utilize the TTM constructs to reduce sedentary behaviors than those in later stages. A lack of association between physical activity and the psychological determinants of sedentary behavior was found.

The fractal geometry of Hartree-Fock

NASA Astrophysics Data System (ADS)

Theel, Friethjof; Karamatskou, Antonia; Santra, Robin

2017-12-01

The Hartree-Fock method is an important approximation for the ground-state electronic wave function of atoms and molecules so that its usage is widespread in computational chemistry and physics. The Hartree-Fock method is an iterative procedure in which the electronic wave functions of the occupied orbitals are determined. The set of functions found in one step builds the basis for the next iteration step. In this work, we interpret the Hartree-Fock method as a dynamical system since dynamical systems are iterations where iteration steps represent the time development of the system, as encountered in the theory of fractals. The focus is put on the convergence behavior of the dynamical system as a function of a suitable control parameter. In our case, a complex parameter λ controls the strength of the electron-electron interaction. An investigation of the convergence behavior depending on the parameter λ is performed for helium, neon, and argon. We observe fractal structures in the complex λ-plane, which resemble the well-known Mandelbrot set, determine their fractal dimension, and find that with increasing nuclear charge, the fragmentation increases as well.

Electric foot shock stress adaptation: Does it exist or not?

PubMed

Bali, Anjana; Jaggi, Amteshwar Singh

2015-06-01

Stress adaptation is a protective phenomenon against repeated stress exposure and is characterized by a decreased responsiveness to a repeated stress stimulus. The adaptation is associated with a complex cascade of events, including the changes in behavior, neurotransmitter and gene expression levels. The non-adaptation or maladaptation to stress may underlie the affective disorders, such as anxiety, depression and post-traumatic stress disorder (PTSD). Electric foot shock is a complex stressor, which includes both physical and emotional components. Unlike immobilization, restraint and cold immersion stress, the phenomenon of stress adaptation is not very well defined in response to electric foot shock. A number of preclinical studies have reported the development of adaptation to electric foot shock stress. However, evidence also reveals the non-adaptive behavior in response to foot shocks. The distinct adaptive/non-adaptive responses may be possibly influenced by the type, intensity, and duration of the stress. The present review discusses the existence or non-existence of adaptation to electric foot shock stress along with possible mechanism. Copyright © 2015 Elsevier Inc. All rights reserved.

Classification of electronically generated phantom targets by an Atlantic bottlenose dolphin (Tursiops truncatus).

PubMed

Aubauer, R; Au, W W; Nachtigall, P E; Pawloski, D A; DeLong, C M

2000-05-01

Animal behavior experiments require not only stimulus control of the animal's behavior, but also precise control of the stimulus itself. In discrimination experiments with real target presentation, the complex interdependence between the physical dimensions and the backscattering process of an object make it difficult to extract and control relevant echo parameters separately. In other phantom-echo experiments, the echoes were relatively simple and could only simulate certain properties of targets. The echo-simulation method utilized in this paper can be used to transform any animal echolocation sound into phantom echoes of high fidelity and complexity. The developed phantom-echo system is implemented on a digital signal-processing board and gives an experimenter fully programmable control over the echo-generating process and the echo structure itself. In this experiment, the capability of a dolphin to discriminate between acoustically simulated phantom replicas of targets and their real equivalents was tested. Phantom replicas were presented in a probe technique during a materials discrimination experiment. The animal accepted the phantom echoes and classified them in the same manner as it classified real targets.

Active Learning for Directed Exploration of Complex Systems

NASA Technical Reports Server (NTRS)

Burl, Michael C.; Wang, Esther

2009-01-01

Physics-based simulation codes are widely used in science and engineering to model complex systems that would be infeasible to study otherwise. Such codes provide the highest-fidelity representation of system behavior, but are often so slow to run that insight into the system is limited. For example, conducting an exhaustive sweep over a d-dimensional input parameter space with k-steps along each dimension requires k(sup d) simulation trials (translating into k(sup d) CPU-days for one of our current simulations). An alternative is directed exploration in which the next simulation trials are cleverly chosen at each step. Given the results of previous trials, supervised learning techniques (SVM, KDE, GP) are applied to build up simplified predictive models of system behavior. These models are then used within an active learning framework to identify the most valuable trials to run next. Several active learning strategies are examined including a recently-proposed information-theoretic approach. Performance is evaluated on a set of thirteen synthetic oracles, which serve as surrogates for the more expensive simulations and enable the experiments to be replicated by other researchers.

Behavior Management in Physical Education, Recreation, and Sport: A Bibliography.

ERIC Educational Resources Information Center

Lavay, Barry

1986-01-01

This bibliography contains references specifically pertaining to physical education, recreation, or sport and to behavior management. The references are classified into areas of behavior management overview, reinforcement systems, motor performance, physical fitness, recreation, and sport. (MT)

Cardiovascular risk profile: cross-sectional analysis of motivational determinants, physical fitness and physical activity.

PubMed

Sassen, Barbara; Kok, Gerjo; Schaalma, Herman; Kiers, Henri; Vanhees, Luc

2010-10-07

Cardiovascular risk factors are associated with physical fitness and, to a lesser extent, physical activity. Lifestyle interventions directed at enhancing physical fitness in order to decrease the risk of cardiovascular diseases should be extended. To enable the development of effective lifestyle interventions for people with cardiovascular risk factors, we investigated motivational, social-cognitive determinants derived from the Theory of Planned Behavior (TPB) and other relevant social psychological theories, next to physical activity and physical fitness. In the cross-sectional Utrecht Police Lifestyle Intervention Fitness and Training (UP-LIFT) study, 1298 employees (aged 18 to 62) were asked to complete online questionnaires regarding social-cognitive variables and physical activity. Cardiovascular risk factors and physical fitness (peak VO2) were measured. For people with one or more cardiovascular risk factors (78.7% of the total population), social-cognitive variables accounted for 39% (p < .001) of the variance in the intention to engage in physical activity for 60 minutes every day. Important correlates of intention to engage in physical activity were attitude (beta = .225, p < .001), self-efficacy (beta = .271, p < .001), descriptive norm (beta = .172, p < .001) and barriers (beta = -.169, p < .01). Social-cognitive variables accounted for 52% (p < .001) of the variance in physical active behaviour (being physical active for 60 minutes every day). The intention to engage in physical activity (beta = .469, p < .001) and self-efficacy (beta = .243, p < .001) were, in turn, important correlates of physical active behavior.In addition to the prediction of intention to engage in physical activity and physical active behavior, we explored the impact of the intensity of physical activity. The intensity of physical activity was only significantly related to physical active behavior (beta = .253, p < .01, R2 = .06, p < .001). An important goal of our study was to investigate the relationship between physical fitness, the intensity of physical activity and social-cognitive variables. Physical fitness (R2 = .23, p < .001) was positively associated with physical active behavior (beta = .180, p < .01), self-efficacy (beta = .180, p < .01) and the intensity of physical activity (beta = .238, p < .01).For people with one or more cardiovascular risk factors, 39.9% had positive intentions to engage in physical activity and were also physically active, and 10.5% had a low intentions but were physically active. 37.7% had low intentions and were physically inactive, and about 11.9% had high intentions but were physically inactive. This study contributes to our ability to optimize cardiovascular risk profiles by demonstrating an important association between physical fitness and social-cognitive variables. Physical fitness can be predicted by physical active behavior as well as by self-efficacy and the intensity of physical activity, and the latter by physical active behavior.Physical active behavior can be predicted by intention, self-efficacy, descriptive norms and barriers. Intention to engage in physical activity by attitude, self-efficacy, descriptive norms and barriers. An important input for lifestyle changes for people with one or more cardiovascular risk factors was that for ca. 40% of the population the intention to engage in physical activity was in line with their actual physical active behavior.

Synthetic Earthquake Statistics From Physical Fault Models for the Lower Rhine Embayment

NASA Astrophysics Data System (ADS)

Brietzke, G. B.; Hainzl, S.; Zöller, G.

2012-04-01

As of today, seismic risk and hazard estimates mostly use pure empirical, stochastic models of earthquake fault systems tuned specifically to the vulnerable areas of interest. Although such models allow for reasonable risk estimates they fail to provide a link between the observed seismicity and the underlying physical processes. Solving a state-of-the-art fully dynamic description set of all relevant physical processes related to earthquake fault systems is likely not useful since it comes with a large number of degrees of freedom, poor constraints on its model parameters and a huge computational effort. Here, quasi-static and quasi-dynamic physical fault simulators provide a compromise between physical completeness and computational affordability and aim at providing a link between basic physical concepts and statistics of seismicity. Within the framework of quasi-static and quasi-dynamic earthquake simulators we investigate a model of the Lower Rhine Embayment (LRE) that is based upon seismological and geological data. We present and discuss statistics of the spatio-temporal behavior of generated synthetic earthquake catalogs with respect to simplification (e.g. simple two-fault cases) as well as to complication (e.g. hidden faults, geometric complexity, heterogeneities of constitutive parameters).

Sociodemographic, developmental, environmental, and psychological correlates of physical activity and sedentary behavior at age 11 to 12.

PubMed

Brodersen, Naomi Henning; Steptoe, Andrew; Williamson, Sara; Wardle, Jane

2005-02-01

Low levels of physical activity and high levels of sedentary behavior during adolescence are a cause for concern. Sociodemographic, developmental, environmental, and psychological factors may be relevant, but the correlates of these behaviors may differ. To investigate the multidimensional correlates of physical activity and sedentary behavior in a large sample of 11- to 12-year-old boys and girls. Cross-sectional survey of 2,578 boys and 1,742 girls from 36 schools stratified by socioeconomic background and gender mix of students (84% response rate). Questionnaire assessments and objective measurements of height and weight were obtained. Days of vigorous physical activity and hours of sedentary behaviors over the past week were uncorrelated. Ethnicity, socioeconomic factors, developmental stage, environmental factors, and psychological variables were associated with physical activity and sedentary behavior in univariate analyses. In multiple regression, sedentary behavior was greater in ethnic minority groups, in students from more deprived backgrounds, and in those with conduct problems. Girls who were more advanced developmentally and who reported emotional symptoms also engaged in more sedentary behaviors. Vigorous physical activity was associated with good self-rated health, prosocial psychological characteristics, and (in boys) with low emotional symptoms. A multidimensional approach to understanding the context of physical activity in early adolescence is needed because factors in several domains are relevant. The correlates of physical activity and sedentary behaviors are distinct in this age group, and there are also important gender differences.

Time Dependent Data Mining in RAVEN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cogliati, Joshua Joseph; Chen, Jun; Patel, Japan Ketan

RAVEN is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. The goal of this type of analyses is to understand the response of such systems in particular with respect their probabilistic behavior, to understand their predictability and drivers or lack of thereof. Data mining capabilities are the cornerstones to perform such deep learning of system responses. For this reason static data mining capabilities were added last fiscal year (FY 15). In real applications, when dealing with complex multi-scale, multi-physics systems it seems natural that, during transients, the relevance of themore » different scales, and physics, would evolve over time. For these reasons the data mining capabilities have been extended allowing their application over time. In this writing it is reported a description of the new RAVEN capabilities implemented with several simple analytical tests to explain their application and highlight the proper implementation. The report concludes with the application of those newly implemented capabilities to the analysis of a simulation performed with the Bison code.« less

Intrinsic brain networks normalize with treatment in pediatric complex regional pain syndrome

PubMed Central

Becerra, Lino; Sava, Simona; Simons, Laura E.; Drosos, Athena M.; Sethna, Navil; Berde, Charles; Lebel, Alyssa A.; Borsook, David

2014-01-01

Pediatric complex regional pain syndrome (P-CRPS) offers a unique model of chronic neuropathic pain as it either resolves spontaneously or through therapeutic interventions in most patients. Here we evaluated brain changes in well-characterized children and adolescents with P-CRPS by measuring resting state networks before and following a brief (median = 3 weeks) but intensive physical and psychological treatment program, and compared them to matched healthy controls. Differences in intrinsic brain networks were observed in P-CRPS compared to controls before treatment (disease state) with the most prominent differences in the fronto-parietal, salience, default mode, central executive, and sensorimotor networks. Following treatment, behavioral measures demonstrated a reduction of symptoms and improvement of physical state (pain levels and motor functioning). Correlation of network connectivities with spontaneous pain measures pre- and post-treatment indicated concomitant reductions in connectivity in salience, central executive, default mode and sensorimotor networks (treatment effects). These results suggest a rapid alteration in global brain networks with treatment and provide a venue to assess brain changes in CRPS pre- and post-treatment, and to evaluate therapeutic effects. PMID:25379449

Linking market interaction intensity of 3D Ising type financial model with market volatility

NASA Astrophysics Data System (ADS)

Fang, Wen; Ke, Jinchuan; Wang, Jun; Feng, Ling

2016-11-01

Microscopic interaction models in physics have been used to investigate the complex phenomena of economic systems. The simple interactions involved can lead to complex behaviors and help the understanding of mechanisms in the financial market at a systemic level. This article aims to develop a financial time series model through 3D (three-dimensional) Ising dynamic system which is widely used as an interacting spins model to explain the ferromagnetism in physics. Through Monte Carlo simulations of the financial model and numerical analysis for both the simulation return time series and historical return data of Hushen 300 (HS300) index in Chinese stock market, we show that despite its simplicity, this model displays stylized facts similar to that seen in real financial market. We demonstrate a possible underlying link between volatility fluctuations of real stock market and the change in interaction strengths of market participants in the financial model. In particular, our stochastic interaction strength in our model demonstrates that the real market may be consistently operating near the critical point of the system.

Preschool Gender-Typed Play Behavior at Age 3.5 Years Predicts Physical Aggression at Age 13 Years.

PubMed

Kung, Karson T F; Li, Gu; Golding, Jean; Hines, Melissa

2018-05-01

Gender differences in play behavior and physical aggression have been consistently reported. Theoretical perspectives concerning evolutionary, social, and social-cognitive mechanisms suggest that male-typical play behavior during childhood increases subsequent physical aggression. The evidence supporting these connections is limited, however. The present study investigated the association between gender-typed play behavior in early childhood and physical aggression in early adolescence using a sample drawn from a longitudinal, population study, the Avon Longitudinal Study of Parents and Children. Based on gender-typed play behavior as measured by the Pre-School Activities Inventory at age 3.5 years, samples of masculine (64 boys, 60 girls), feminine (80 boys, 66 girls), and randomly selected control children (55 boys, 67 girls) were recruited at age 13 years and administered the Reinisch Aggression Inventory. After controlling for a range of sociodemographic variables, maternal characteristics, and behavioral problems, including hyperactivity and conduct problems at age 3.5, significant group differences in physical aggression at age 13 were found among children classified as masculine, control, and feminine at age 3.5. Masculine children exhibited significantly more physical aggression than control children or feminine children, and control children exhibited significantly more physical aggression than feminine children. The association between gender-typed play behavior and physical aggression was not moderated by sex. These results suggest that the degree of childhood gender-typed play behavior independently predicts the degree of physical aggression at adolescence in boys and in girls.

Neighborhood environment correlates of physical activity and sedentary behavior among Latino adults in Massachusetts.

PubMed

Silfee, Valerie J; Rosal, Milagros C; Sreedhara, Meera; Lora, Vilma; Lemon, Stephenie C

2016-09-13

U.S. Latinos experience high rates of cardio-metabolic diseases and have high rates of physical inactivity and sedentary behavior. Understanding the environmental factors associated with physical activity and sedentary behaviors among Latinos could inform future interventions. The purpose of this study is to explore the neighborhood environment correlates of physical activity and sedentary behavior in a sample of U.S. Latino adults. Cross-sectional study of 602 Latino adults in Lawrence, MA. Survey assessments of physical activity, sedentary behavior, and neighborhood environment were verbally administered. The neighborhood environment scale assessed violence, safety, aesthetic quality, walkability, availability of healthy foods, social cohesion, and activities with neighbors. After controlling forage, gender, education, body mass index (BMI), and smoking status, two variables were associated with the outcomes of interest. Living in more walkable neighborhoods was associated with an increased likelihood of engaging in adequate levels of physical activity (>150 min per week, as recommended by the American College of Sports Medicine (ACSM)) (OR = 1.403, p = .018); and greater frequency of activities with neighbors was associated with greater sedentary behavior (β = .072, p = .05). There were different neighborhood environment correlates of physical activity and sedentary behavior in this Latino community. Focusing on a greater understanding of the distinct social and physical environmental correlates of physical activity and sedentary behavior may provide important insights for reducing CVD risk and health disparities among Latinos.

Modeling and simulation of dust behaviors behind a moving vehicle

NASA Astrophysics Data System (ADS)

Wang, Jingfang

Simulation of physically realistic complex dust behaviors is a difficult and attractive problem in computer graphics. A fast, interactive and visually convincing model of dust behaviors behind moving vehicles is very useful in computer simulation, training, education, art, advertising, and entertainment. In my dissertation, an experimental interactive system has been implemented for the simulation of dust behaviors behind moving vehicles. The system includes physically-based models, particle systems, rendering engines and graphical user interface (GUI). I have employed several vehicle models including tanks, cars, and jeeps to test and simulate in different scenarios and conditions. Calm weather, winding condition, vehicle turning left or right, and vehicle simulation controlled by users from the GUI are all included. I have also tested the factors which play against the physical behaviors and graphics appearances of the dust particles through GUI or off-line scripts. The simulations are done on a Silicon Graphics Octane station. The animation of dust behaviors is achieved by physically-based modeling and simulation. The flow around a moving vehicle is modeled using computational fluid dynamics (CFD) techniques. I implement a primitive variable and pressure-correction approach to solve the three dimensional incompressible Navier Stokes equations in a volume covering the moving vehicle. An alternating- direction implicit (ADI) method is used for the solution of the momentum equations, with a successive-over- relaxation (SOR) method for the solution of the Poisson pressure equation. Boundary conditions are defined and simplified according to their dynamic properties. The dust particle dynamics is modeled using particle systems, statistics, and procedure modeling techniques. Graphics and real-time simulation techniques, such as dynamics synchronization, motion blur, blending, and clipping have been employed in the rendering to achieve realistic appearing dust behaviors. In addition, I introduce a temporal smoothing technique to eliminate the jagged effect caused by large simulation time. Several algorithms are used to speed up the simulation. For example, pre-calculated tables and display lists are created to replace some of the most commonly used functions, scripts and processes. The performance study shows that both time and space costs of the algorithms are linear in the number of particles in the system. On a Silicon Graphics Octane, three vehicles with 20,000 particles run at 6-8 frames per second on average. This speed does not include the extra calculations of convergence of the numerical integration for fluid dynamics which usually takes about 4-5 minutes to achieve steady state.

Behavioral Priming 2.0: Enter a Dynamical Systems Perspective

PubMed Central

Krpan, Dario

2017-01-01

On a daily basis, people are exposed to numerous stimuli, ranging from colors and smells to sounds and words, that could potentially activate different cognitive constructs and influence their actions. This type of influence on human behavior is referred to as priming. Roughly two decades ago, behavioral priming was hailed as one of the core forces that shape automatic behavior. However, failures to replicate some of the representative findings in this domain soon followed, which posed the following question: “How robust are behavioral priming effects, and to what extent are they actually important in shaping people's actions?” To shed a new light on this question, I revisit behavioral priming through the prism of a dynamical systems perspective (DSP). The DSP is a scientific paradigm that has been developed through a combined effort of many different academic disciplines, ranging from mathematics and physics to biology, economics, psychology, etc., and it deals with behavior of simple and complex systems over time. In the present paper, I use conceptual and methodological tools stemming from the DSP to propose circumstances under which behavioral priming effects are likely to occur. More precisely, I outline three possible types of the influence of priming on human behavior, to which I refer as emergence, readjustment, and attractor switch, and propose experimental designs to examine them. Finally, I discuss relevant implications for behavioral priming effects and their replications. PMID:28769846

The detrimental effects of physical restraint as a consequence for inappropriate classroom behavior.

PubMed

Magee, S K; Ellis, J

2001-01-01

Functional analyses produced inconclusive results regarding variables that maintained problem behavior for 2 students with developmental disabilities. Procedures were modified to include a contingent physical restraint condition based on in-class observations. Results indicated that tinder conditions in which physical restraint (i.e., basket-hold timeout) was applied contingent on problem behavior, rates of these behaviors increased across sessions for both subjects. Implications for the use of physical restraint in the classroom are discussed.

Guided goal setting: effectiveness in a dietary and physical activity intervention with low-income adolescents.

PubMed

Shilts, Mical Kay; Horowitz, Marcel; Townsend, Marilyn S

2009-01-01

Determining the effectiveness of the guided goal setting strategy on changing adolescents' dietary and physical activity self-efficacy and behaviors. Adolescents were individually assigned to treatment (intervention with guided goal setting) or control conditions (intervention without guided goal setting) with data collected before and after the education intervention. Urban middle school in a low-income community in Central California. Ethnically diverse middle school students (n = 94, 55% male) who were participants of a USDA nutrition education program. Driven by the Social Cognitive Theory, the intervention targeted dietary and physical activity behaviors of adolescents. Dietary self-efficacy and behavior; physical activity self-efficacy and behavior; goal effort and spontaneous goal setting. ANCOVA and path analysis were performed using the full sample and a sub-sample informed by Locke's recommendations (accounting for goal effort and spontaneous goal setting). No significant differences were found between groups using the full sample. Using the sub-sample, greater gains in dietary behavior (p < .05), physical activity behavior (p < .05), and physical activity self-efficacy (p < .05) were made by treatment participants compared to control participants. Change in physical activity behaviors was mediated by self-efficacy. Accounting for goal effort and spontaneous goal setting, this study provides some evidence that the use of guided goal setting with adolescents may be a viable strategy to promote dietary and physical activity behavior change.

City rats: insight from rat spatial behavior into human cognition in urban environments.

PubMed

Yaski, Osnat; Portugali, Juval; Eilam, David

2011-09-01

The structure and shape of the urban environment influence our ability to find our way about in the city. Understanding how the physical properties of the environment affect spatial behavior and cognition is therefore a necessity. However, there are inherent difficulties in empirically studying complex and large-scale urban environments. These include the need to isolate the impact of specific urban features and to acquire data on the physical activity of individuals. In the present study, we attempted to overcome the above obstacles and examine the relation between urban environments and spatial cognition by testing the spatial behavior of rats. This idea originated from the resemblance in the operative brain functions and in the mechanisms and strategies employed by humans and other animals when acquiring spatial information and establishing an internal representation, as revealed in past studies. Accordingly, we tested rats in arenas that simulated a grid urban layout (e.g. Manhattan streets) and an irregular urban layout (e.g. Jerusalem streets). We found that in the grid layout, rat movement was more structured and extended over a greater area compared with their restricted movement in the irregular layout. These movement patterns recall those of humans in respective urban environments, illustrating that the structure and shape of the environment affect spatial behavior similarly in humans and rats. Overall, testing rats in environments that simulate facets of urban environments can provide new insights into human spatial cognition in urban environments.

Relationship between Physical Disabilities or Long-Term Health Problems and Health Risk Behaviors or Conditions among US High School Students

ERIC Educational Resources Information Center

Jones, Sherry Everett; Lollar, Donald J.

2008-01-01

Background: This study explores the relationship between self-reported physical disabilities or long-term health problems and health risk behaviors or adverse health conditions (self-reported engagement in violent behaviors, attempted suicide, cigarette smoking, alcohol and other drug use, sexual activity, physical activity, dietary behaviors,…

Coexistence of a well-determined kinetic law and a scale-invariant power law during the same physical process

NASA Astrophysics Data System (ADS)

Zreihan, Noam; Faran, Eilon; Vives, Eduard; Planes, Antoni; Shilo, Doron

2018-01-01

It is generally claimed that physical processes which display scale-invariant power-law distributions are subjected to a dynamic criticality that prohibits a well-defined kinetic law. In this paper, we demonstrate the coexistence of these two apparently contradicting behaviors during the same physical process—the motion of type-II twin boundaries in martensite Ni-Mn-Ga. The process is investigated by combined measurements of the temporal twin-boundary velocity and the acoustic emitted energy. Velocity values are extracted from high-resolution force measurements taken during displacement-driven mechanical tests, as well as from force-driven magnetic tests, and cover an overall range of six orders of magnitude. Acoustic emission (AE) is measured during mechanical tests. Velocity values follow a normal distribution whose characteristic value is determined by the material's kinetic relation, and its width scales with the average velocity. In addition, it is observed that velocity distributions are characterized by a heavy tail at the right (i.e., faster) end that exhibits a power law over more than one and a half orders of magnitude. At the same time, the AE signals follow a scale-invariant power-law distribution, which is not sensitive to the average twin-boundary velocity. The coexistence of these two different statistical behaviors reflects the complex nature of twin-boundary motion and suggests the possibility that the transformation proceeds through physical subprocesses that are close to criticality alongside other processes that are not.

Modeling socio-cultural processes in network-centric environments

NASA Astrophysics Data System (ADS)

Santos, Eunice E.; Santos, Eugene, Jr.; Korah, John; George, Riya; Gu, Qi; Kim, Keumjoo; Li, Deqing; Russell, Jacob; Subramanian, Suresh

2012-05-01

The major focus in the field of modeling & simulation for network centric environments has been on the physical layer while making simplifications for the human-in-the-loop. However, the human element has a big impact on the capabilities of network centric systems. Taking into account the socio-behavioral aspects of processes such as team building, group decision-making, etc. are critical to realistically modeling and analyzing system performance. Modeling socio-cultural processes is a challenge because of the complexity of the networks, dynamism in the physical and social layers, feedback loops and uncertainty in the modeling data. We propose an overarching framework to represent, model and analyze various socio-cultural processes within network centric environments. The key innovation in our methodology is to simultaneously model the dynamism in both the physical and social layers while providing functional mappings between them. We represent socio-cultural information such as friendships, professional relationships and temperament by leveraging the Culturally Infused Social Network (CISN) framework. The notion of intent is used to relate the underlying socio-cultural factors to observed behavior. We will model intent using Bayesian Knowledge Bases (BKBs), a probabilistic reasoning network, which can represent incomplete and uncertain socio-cultural information. We will leverage previous work on a network performance modeling framework called Network-Centric Operations Performance and Prediction (N-COPP) to incorporate dynamism in various aspects of the physical layer such as node mobility, transmission parameters, etc. We validate our framework by simulating a suitable scenario, incorporating relevant factors and providing analyses of the results.

Temporal self-regulation theory: a neurobiologically informed model for physical activity behavior

PubMed Central

Hall, Peter A.; Fong, Geoffrey T.

2015-01-01

Dominant explanatory models for physical activity behavior are limited by the exclusion of several important components, including temporal dynamics, ecological forces, and neurobiological factors. The latter may be a critical omission, given the relevance of several aspects of cognitive function for the self-regulatory processes that are likely required for consistent implementation of physical activity behavior in everyday life. This narrative review introduces temporal self-regulation theory (TST; Hall and Fong, 2007, 2013) as a new explanatory model for physical activity behavior. Important features of the model include consideration of the default status of the physical activity behavior, as well as the disproportionate influence of temporally proximal behavioral contingencies. Most importantly, the TST model proposes positive feedback loops linking executive function (EF) and the performance of physical activity behavior. Specifically, those with relatively stronger executive control (and optimized brain structures supporting it, such as the dorsolateral prefrontal cortex (PFC)) are able to implement physical activity with more consistency than others, which in turn serves to strengthen the executive control network itself. The TST model has the potential to explain everyday variants of incidental physical activity, sport-related excellence via capacity for deliberate practice, and variability in the propensity to schedule and implement exercise routines. PMID:25859196

Physical Activity Patterns and Sedentary Behavior in Older Women With Urinary Incontinence: an Accelerometer-based Study.

PubMed

Chu, Christine M; Khanijow, Kavita D; Schmitz, Kathryn H; Newman, Diane K; Arya, Lily A; Harvie, Heidi S

2018-01-10

Objective physical activity data for women with urinary incontinence are lacking. We investigated the relationship between physical activity, sedentary behavior, and the severity of urinary symptoms in older community-dwelling women with urinary incontinence using accelerometers. This is a secondary analysis of a study that measured physical activity (step count, moderate-to-vigorous physical activity time) and sedentary behavior (percentage of sedentary time, number of sedentary bouts per day) using a triaxial accelerometer in older community-dwelling adult women not actively seeking treatment of their urinary symptoms. The relationship between urinary symptoms and physical activity variables was measured using linear regression. Our cohort of 35 community-dwelling women (median, age, 71 years) demonstrated low physical activity (median daily step count, 2168; range, 687-5205) and high sedentary behavior (median percentage of sedentary time, 74%; range, 54%-89%). Low step count was significantly associated with nocturia (P = 0.02). Shorter duration of moderate-to-vigorous physical activity time was significantly associated with nocturia (P = 0.001), nocturnal enuresis (P = 0.04), and greater use of incontinence products (P = 0.04). Greater percentage of time spent in sedentary behavior was also significantly associated with nocturia (P = 0.016). Low levels of physical activity are associated with greater nocturia and nocturnal enuresis. Sedentary behavior is a new construct that may be associated with lower urinary tract symptoms. Physical activity and sedentary behavior represent potential new targets for treating nocturnal urinary tract symptoms.

Can simple rules control development of a pioneer vertebrate neuronal network generating behavior?

PubMed

Roberts, Alan; Conte, Deborah; Hull, Mike; Merrison-Hort, Robert; al Azad, Abul Kalam; Buhl, Edgar; Borisyuk, Roman; Soffe, Stephen R

2014-01-08

How do the pioneer networks in the axial core of the vertebrate nervous system first develop? Fundamental to understanding any full-scale neuronal network is knowledge of the constituent neurons, their properties, synaptic interconnections, and normal activity. Our novel strategy uses basic developmental rules to generate model networks that retain individual neuron and synapse resolution and are capable of reproducing correct, whole animal responses. We apply our developmental strategy to young Xenopus tadpoles, whose brainstem and spinal cord share a core vertebrate plan, but at a tractable complexity. Following detailed anatomical and physiological measurements to complete a descriptive library of each type of spinal neuron, we build models of their axon growth controlled by simple chemical gradients and physical barriers. By adding dendrites and allowing probabilistic formation of synaptic connections, we reconstruct network connectivity among up to 2000 neurons. When the resulting "network" is populated by model neurons and synapses, with properties based on physiology, it can respond to sensory stimulation by mimicking tadpole swimming behavior. This functioning model represents the most complete reconstruction of a vertebrate neuronal network that can reproduce the complex, rhythmic behavior of a whole animal. The findings validate our novel developmental strategy for generating realistic networks with individual neuron- and synapse-level resolution. We use it to demonstrate how early functional neuronal connectivity and behavior may in life result from simple developmental "rules," which lay out a scaffold for the vertebrate CNS without specific neuron-to-neuron recognition.

Behavior of Materials Under Conditions of Thermal Stress

NASA Technical Reports Server (NTRS)

Manson, S S

1954-01-01

A review is presented of available information on the behavior of brittle and ductile materials under conditions of thermal stress and thermal shock. For brittle materials, a simple formula relating physical properties to thermal-shock resistance is derived and used to determine the relative significance of two indices currently in use for rating materials. For ductile materials, thermal-shock resistance depends upon the complex interrelation among several metallurgical variables which seriously affect strength and ductility. These variables are briefly discussed and illustrated from literature sources. The importance of simulating operating conditions in tests for rating materials is especially to be emphasized because of the importance of testing conditions in metallurgy. A number of practical methods that have been used to minimize the deleterious effects of thermal stress and thermal shock are outlined.

Host-guest chemistry of cyclodextrin carbamates and cellulose derivatives in aqueous solution.

PubMed

Guo, Xin; Jia, Xiangxiang; Du, Jiaojiao; Xiao, Longqiang; Li, Feifei; Liao, Liqiong; Liu, Lijian

2013-10-15

Supramolecular polymer micelles were prepared on basis of the inclusion complexation between cyclodextrin carbamates and cellulose derivatives in aqueous media. Cyclodextrin carbamates were synthesized by microwave-assisted method from cyclodextrin and urea. The urea modified cyclodextrin shows the higher yield than the physical mixture of urea/cyclodextrin in the micellization with cellulose derivatives. The supramolecular structure of the core-shell micelles was demonstrated by (1)H NMR spectra, TEM images, and fluorescence spectra. The drug release behavior of the supramolecular polymer micelles was evaluated using prednisone acetate as a model drug. The drug loaded micelles showed steady and long time drug release behavior. With these properties, the supramolecular polymer micelles are attractive as drug carriers for pharmaceutical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Towards a unified study of extreme events using universality concepts and transdisciplinary analysis methods

NASA Astrophysics Data System (ADS)

Balasis, George; Donner, Reik V.; Donges, Jonathan F.; Radebach, Alexander; Eftaxias, Konstantinos; Kurths, Jürgen

2013-04-01

The dynamics of many complex systems is characterized by the same universal principles. In particular, systems which are otherwise quite different in nature show striking similarities in their behavior near tipping points (bifurcations, phase transitions, sudden regime shifts) and associated extreme events. Such critical phenomena are frequently found in diverse fields such as climate, seismology, or financial markets. Notably, the observed similarities include a high degree of organization, persistent behavior, and accelerated energy release, which are common to (among others) phenomena related to geomagnetic variability of the terrestrial magnetosphere (intense magnetic storms), seismic activity (electromagnetic emissions prior to earthquakes), solar-terrestrial physics (solar flares), neurophysiology (epileptic seizures), and socioeconomic systems (stock market crashes). It is an open question whether the spatial and temporal complexity associated with extreme events arises from the system's structural organization (geometry) or from the chaotic behavior inherent to the nonlinear equations governing the dynamics of these phenomena. On the one hand, the presence of scaling laws associated with earthquakes and geomagnetic disturbances suggests understanding these events as generalized phase transitions similar to nucleation and critical phenomena in thermal and magnetic systems. On the other hand, because of the structural organization of the systems (e.g., as complex networks) the associated spatial geometry and/or topology of interactions plays a fundamental role in the emergence of extreme events. Here, a few aspects of the interplay between geometry and dynamics (critical phase transitions) that could result in the emergence of extreme events, which is an open problem, will be discussed.

Social behavior of bacteria: from physics to complex organization

NASA Astrophysics Data System (ADS)

Ben-Jacob, E.

2008-10-01

I describe how bacteria develop complex colonial patterns by utilizing intricate communication capabilities, such as quorum sensing, chemotactic signaling and exchange of genetic information (plasmids) Bacteria do not store genetically all the information required for generating the patterns for all possible environments. Instead, additional information is cooperatively generated as required for the colonial organization to proceed. Each bacterium is, by itself, a biotic autonomous system with its own internal cellular informatics capabilities (storage, processing and assessments of information). These afford the cell certain plasticity to select its response to biochemical messages it receives, including self-alteration and broadcasting messages to initiate alterations in other bacteria. Hence, new features can collectively emerge during self-organization from the intra-cellular level to the whole colony. Collectively bacteria store information, perform decision make decisions (e.g. to sporulate) and even learn from past experience (e.g. exposure to antibiotics)-features we begin to associate with bacterial social behavior and even rudimentary intelligence. I also take Schrdinger’s’ “feeding on negative entropy” criteria further and propose that, in addition organisms have to extract latent information embedded in the environment. By latent information we refer to the non-arbitrary spatio-temporal patterns of regularities and variations that characterize the environmental dynamics. In other words, bacteria must be able to sense the environment and perform internal information processing for thriving on latent information embedded in the complexity of their environment. I then propose that by acting together, bacteria can perform this most elementary cognitive function more efficiently as can be illustrated by their cooperative behavior.

Multi-Dimensional Simulation of LWR Fuel Behavior in the BISON Fuel Performance Code

NASA Astrophysics Data System (ADS)

Williamson, R. L.; Capps, N. A.; Liu, W.; Rashid, Y. R.; Wirth, B. D.

2016-11-01

Nuclear fuel operates in an extreme environment that induces complex multiphysics phenomena occurring over distances ranging from inter-atomic spacing to meters, and times scales ranging from microseconds to years. To simulate this behavior requires a wide variety of material models that are often complex and nonlinear. The recently developed BISON code represents a powerful fuel performance simulation tool based on its material and physical behavior capabilities, finite-element versatility of spatial representation, and use of parallel computing. The code can operate in full three dimensional (3D) mode, as well as in reduced two dimensional (2D) modes, e.g., axisymmetric radial-axial ( R- Z) or plane radial-circumferential ( R- θ), to suit the application and to allow treatment of global and local effects. A BISON case study was used to illustrate analysis of Pellet Clad Mechanical Interaction failures from manufacturing defects using combined 2D and 3D analyses. The analysis involved commercial fuel rods and demonstrated successful computation of metrics of interest to fuel failures, including cladding peak hoop stress and strain energy density. In comparison with a failure threshold derived from power ramp tests, results corroborate industry analyses of the root cause of the pellet-clad interaction failures and illustrate the importance of modeling 3D local effects around fuel pellet defects, which can produce complex effects including cold spots in the cladding, stress concentrations, and hot spots in the fuel that can lead to enhanced cladding degradation such as hydriding, oxidation, CRUD formation, and stress corrosion cracking.

Multi-Dimensional Simulation of LWR Fuel Behavior in the BISON Fuel Performance Code

DOE PAGES

Williamson, R. L.; Capps, N. A.; Liu, W.; ...

2016-09-27

Nuclear fuel operates in an extreme environment that induces complex multiphysics phenomena occurring over distances ranging from inter-atomic spacing to meters, and times scales ranging from microseconds to years. To simulate this behavior requires a wide variety of material models that are often complex and nonlinear. The recently developed BISON code represents a powerful fuel performance simulation tool based on its material and physical behavior capabilities, finite-element versatility of spatial representation, and use of parallel computing. The code can operate in full three dimensional (3D) mode, as well as in reduced two dimensional (2D) modes, e.g., axisymmetric radial-axial (R-Z) ormore » plane radial-circumferential (R-θ), to suit the application and to allow treatment of global and local effects. A BISON case study was used in this paper to illustrate analysis of Pellet Clad Mechanical Interaction failures from manufacturing defects using combined 2D and 3D analyses. The analysis involved commercial fuel rods and demonstrated successful computation of metrics of interest to fuel failures, including cladding peak hoop stress and strain energy density. Finally, in comparison with a failure threshold derived from power ramp tests, results corroborate industry analyses of the root cause of the pellet-clad interaction failures and illustrate the importance of modeling 3D local effects around fuel pellet defects, which can produce complex effects including cold spots in the cladding, stress concentrations, and hot spots in the fuel that can lead to enhanced cladding degradation such as hydriding, oxidation, CRUD formation, and stress corrosion cracking.« less

Discrete Dynamics Lab

NASA Astrophysics Data System (ADS)

Wuensche, Andrew

DDLab is interactive graphics software for creating, visualizing, and analyzing many aspects of Cellular Automata, Random Boolean Networks, and Discrete Dynamical Networks in general and studying their behavior, both from the time-series perspective — space-time patterns, and from the state-space perspective — attractor basins. DDLab is relevant to research, applications, and education in the fields of complexity, self-organization, emergent phenomena, chaos, collision-based computing, neural networks, content addressable memory, genetic regulatory networks, dynamical encryption, generative art and music, and the study of the abstract mathematical/physical/dynamical phenomena in their own right.

SpaceX CRS-11 Liftoff

NASA Image and Video Library

2017-06-03

A SpaceX Falcon 9 rocket lifts off from Launch Complex 39A at NASA's Kenney Space Center in Florida, the company's 11th commercial resupply services mission to the International Space Station. Liftoff was at 5:07 p.m. EDT from the historic launch site now operated by SpaceX under a property agreement with NASA. The Dragon spacecraft will deliver 6,000 pounds of supplies, such as the Neutron star Interior Composition Explorer, or NICER, designed to study the extraordinary physics of these stars, providing insights into their nature and behavior.

Approaching the molecular origins of collective dynamics in oscillating cell populations

PubMed Central

Mehta, Pankaj; Gregor, Thomas

2011-01-01

From flocking birds, to organ generation, to swarming bacterial colonies, biological systems often exhibit collective behaviors. Here, we review recent advances in our understanding of collective dynamics in cell populations. We argue that understanding population-level oscillations requires examining the system under consideration at three different levels of complexity: at the level of isolated cells, homogenous populations, and spatially structured populations. We discuss the experimental and theoretical challenges this poses and highlight how new experimental techniques, when combined with conceptual tools adapted from physics, may help us overcome these challenges. PMID:20934869

Rich context information for just-in-time adaptive intervention promoting physical activity.

PubMed

Cruciani, F; Nugent, C; Cleland, I; McCullagh, P

2017-07-01

Sedentary lifestyle and inadequate levels of physical activity represent two serious health risk factors. Nevertheless, within developed countries, 60% of people aged over 60 are deemed to be sedentary. Consequently, interest in behavior change to promote physical activity is increasing. In particular, the role of emerging mobile apps to facilitate behavior change has shown promising results. Smart technologies can help in providing rich context information including an objective assessment of the level of physical activity and information on the emotional and physiological state of the person. Collectively, this can be used to develop innovative persuasive solutions for adaptive behavior change. Such solutions offer potential in reducing levels of sedentary behavior. This work presents a study exploring new ways of employing smart technologies to facilitate behavior change. It is achieved by means of (i) developing a knowledge base on sedentary behaviors and recommended physical activity guidelines, and (ii) a context model able to combine information on physical activity, location, and a user's diary to develop a context-aware virtual coach with the ability to select the most appropriate behavior change strategy on a case by case basis.

Detection of quasars in the time domain

NASA Astrophysics Data System (ADS)

Graham, Matthew J.; Djorgovski, S. G.; Stern, Daniel J.; Drake, Andrew; Mahabal, Ashish

2017-06-01

The time domain is the emerging forefront of astronomical research with new facilities and instruments providing unprecedented amounts of data on the temporal behavior of astrophysical populations. Dealing with the size and complexity of this requires new techniques and methodologies. Quasars are an ideal work set for developing and applying these: they vary in a detectable but not easily quantifiable manner whose physical origins are poorly understood. In this paper, we will review how quasars are identified by their variability and how these techniques can be improved, what physical insights into their variability can be gained from studying extreme examples of variability, and what approaches can be taken to increase the number of quasars known. These will demonstrate how astroinformatics is essential to discovering and understanding this important population.

Successful cognitive and emotional aging

PubMed Central

JESTE, DILIP V.; DEPP, COLIN A.; VAHIA, IPSIT V.

2010-01-01

We review the definitions, determinants, and ways of enhancing successful cognitive and emotional aging. Objective definitions of successful aging based on physical health emphasize outcomes including freedom from disability and disease, whereas subjective definitions center on well-being, social connectedness, and adaptation. Most older people do not meet objective criteria for successful aging, while a majority meet the subjective criteria. Older people with severe mental illness are not excluded from successful aging. The determinants of successful aging include complex interactions of lifestyle behaviors and social environment with genes. Depression interferes with nearly all determinants of successful aging. Evidence-based means of enhancing successful aging include calorie restriction, physical exercise, cognitive stimulation, social support, and optimization of stress. Future directions for successful aging research and implications for geriatric psychiatry are discussed. PMID:20671889

Sculpting bespoke mountains: Determining free energies with basis expansions

NASA Astrophysics Data System (ADS)

Whitmer, Jonathan K.; Fluitt, Aaron M.; Antony, Lucas; Qin, Jian; McGovern, Michael; de Pablo, Juan J.

2015-07-01

The intriguing behavior of a wide variety of physical systems, ranging from amorphous solids or glasses to proteins, is a direct manifestation of underlying free energy landscapes riddled with local minima separated by large barriers. Exploring such landscapes has arguably become one of statistical physics's great challenges. A new method is proposed here for uniform sampling of rugged free energy surfaces. The method, which relies on special Green's functions to approximate the Dirac delta function, improves significantly on existing simulation techniques by providing a boundary-agnostic approach that is capable of mapping complex features in multidimensional free energy surfaces. The usefulness of the proposed approach is established in the context of a simple model glass former and model proteins, demonstrating improved convergence and accuracy over existing methods.

A fluid-filled soft robot that exhibits spontaneous switching among versatile spatiotemporal oscillatory patterns inspired by the true slime mold.

PubMed

Umedachi, Takuya; Idei, Ryo; Ito, Kentaro; Ishiguro, Akio

2013-01-01

Behavioral diversity is an essential feature of living systems, enabling them to exhibit adaptive behavior in hostile and dynamically changing environments. However, traditional engineering approaches strive to avoid, or suppress, the behavioral diversity in artificial systems to achieve high performance in specific environments for given tasks. The goals of this research include understanding how living systems exhibit behavioral diversity and using these findings to build lifelike robots that exhibit truly adaptive behaviors. To this end, we have focused on one of the most primitive forms of intelligence concerning behavioral diversity, namely, a plasmodium of true slime mold. The plasmodium is a large amoeba-like unicellular organism that does not possess any nervous system or specialized organs. However, it exhibits versatile spatiotemporal oscillatory patterns and switches spontaneously between these. Inspired by the plasmodium, we built a mathematical model that exhibits versatile oscillatory patterns and spontaneously transitions between these patterns. This model demonstrates that, in contrast to coupled nonlinear oscillators with a well-designed complex diffusion network, physically interacting mechanosensory oscillators are capable of generating versatile oscillatory patterns without changing any parameters. Thus, the results are expected to shed new light on the design scheme for lifelike robots that exhibit amazingly versatile and adaptive behaviors.

Peer Relations as a Function of Physical Attractiveness: The Eye of the Beholder or Behavioral Reality?

ERIC Educational Resources Information Center

Langlois, Judith H.; Downs, A. Chris

This study examines the relationship between physical attractiveness and behavior by assessing whether behavioral differences exist between children judged by adults to be physically attractive and unattractive. Sixty-four 3- and 5-year-old boys and girls were selected as subjects on the basis of physical attractiveness. Three types of same-age…

Nicotine Dependence, Physical Activity, and Sedentary Behavior among Adult Smokers.

PubMed

Loprinzi, Paul D; Walker, Jerome F

2015-03-01

Research has previously demonstrated an inverse association between smoking status and physical activity; however, few studies have examined the association between nicotine dependence and physical activity or sedentary behavior. This study examined the association between nicotine dependence and accelerometer-determined physical activity and sedentary behavior. Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used. A total of 851 adult (≥20 years) smokers wore an accelerometer for ≥4 days and completed the Fagerstrom Test for Nicotine Dependence scale. Regression models were used to examine the association between nicotine dependence and physical activity/sedentary behavior. After adjusting for age, gender, race-ethnicity, poverty level, hypertension, emphysema, bronchitis, body mass index (BMI), cotinine, and accelerometer wear time, smokers 50 + years of age with greater nicotine dependence engaged in more sedentary behavior (β = 11.4, P = 0.02) and less light-intensity physical activity (β = -9.6, P = 0.03) and moderate-to-vigorous physical activity (MVPA; β = -0.14, P = 0.003) than their less nicotine dependent counterparts. Older adults who are more nicotine dependent engage in less physical activity (both MVPA and light-intensity) and more sedentary behavior than their less nicotine dependent counterparts.

Academic Performance and Lifestyle Behaviors in Australian School Children: A Cluster Analysis.

PubMed

Dumuid, Dorothea; Olds, Timothy; Martín-Fernández, Josep-Antoni; Lewis, Lucy K; Cassidy, Leah; Maher, Carol

2017-12-01

Poor academic performance has been linked with particular lifestyle behaviors, such as unhealthy diet, short sleep duration, high screen time, and low physical activity. However, little is known about how lifestyle behavior patterns (or combinations of behaviors) contribute to children's academic performance. We aimed to compare academic performance across clusters of children with common lifestyle behavior patterns. We clustered participants (Australian children aged 9-11 years, n = 284) into four mutually exclusive groups of distinct lifestyle behavior patterns, using the following lifestyle behaviors as cluster inputs: light, moderate, and vigorous physical activity; sedentary behavior and sleep, derived from 24-hour accelerometry; self-reported screen time and diet. Differences in academic performance (measured by a nationally administered standardized test) were detected across the clusters, with scores being lowest in the Junk Food Screenies cluster (unhealthy diet/high screen time) and highest in the Sitters cluster (high nonscreen sedentary behavior/low physical activity). These findings suggest that reduction in screen time and an improved diet may contribute positively to academic performance. While children with high nonscreen sedentary time performed better academically in this study, they also accumulated low levels of physical activity. This warrants further investigation, given the known physical and mental benefits of physical activity.

Adverse Childhood Experiences and Young Adult Health Outcomes among Youth Aging Out of Foster Care.

PubMed

Rebbe, Rebecca; Nurius, Paula S; Courtney, Mark E; Ahrens, Kym R

2018-04-27

Former youth in foster care (YFC) are at greater risk of chronic health conditions than their peers. Although research in general population samples has demonstrated a dose-response relationship between adverse childhood experiences (ACEs) and adult health outcomes, few studies have conducted similar analyses in highly stress-exposed populations such as YFC. This paper uses person-centered latent class analysis (LCA) methods to examine the relationship between different profiles of ACE exposures and divergent health trajectories amongst this high-risk population. Data are from longitudinal research that followed transition-age YFC from age 17-26 (N =732). Using three subgroups previously identified by their ACEs histories, Complex, Environmental, and Lower Adversity groups, we applied group mean statistics to test for differences between the groups for physical and sexual health outcomes in young adulthood. In contrast to prior research demonstrating that the Environmental group was at the highest risk of criminal behavior outcomes, for most of the physical and sexual health risk outcomes evaluated in this paper, the Complex Adversity group had the highest risk. This study demonstrates that there are subgroups of YFC which each have a distinct profile of risk in young adulthood, with the Complex group being at highest risk of the physical and sexual health risk outcomes evaluated. Findings strongly suggest the need for targeted strategies to promote screening for ACEs and chronic health conditions, linkage to adult healthcare, and continuity of care for adolescents and young adults in foster care to offset these trajectories. Copyright © 2018. Published by Elsevier Inc.

[The dimension of the paradigm of complexity in health systems].

PubMed

Fajardo-Ortiz, Guillermo; Fernández-Ortega, Miguel Ángel; Ortiz-Montalvo, Armando; Olivares-Santos, Roberto Antonio

2015-01-01

This article presents elements to better understand health systems from the complety paradigm, innovative perspective that offers other ways in the conception of the scientific knowledge prevalent away from linear, characterized by the arise of emerging dissociative and behaviors, based on the intra and trans-disciplinarity concepts such knowledges explain and understand in a different way what happens in the health systems with a view to efficiency and effectiveness. The complexity paradigm means another way of conceptualizing the knowledge, is different from the prevalent epistemology, is still under construction does not separate, not isolated, is not reductionist, or fixed, does not solve the problems, but gives other bases to know them and study them, is a different strategy, a perspective that has basis in the systems theory, informatics and cybernetics beyond traditional knowledge, the positive logics, the newtonian physics and symmetric mathematics, in which everything is centered and balanced, joint the "soft sciences and hard sciences", it has present the Social Determinants of Health and organizational culture. Under the complexity paradigm the health systems are identified with the following concepts: entropy, neguentropy, the thermodynamic second law, attractors, chaos theory, fractals, selfmanagement and self-organization, emerging behaviors, percolation, uncertainty, networks and robusteness; such expressions open new possibilities to improve the management and better understanding of the health systems, giving rise to consider health systems as complex adaptive systems. Copyright © 2015. Published by Masson Doyma México S.A.

The Limitations of Model-Based Experimental Design and Parameter Estimation in Sloppy Systems.

PubMed

White, Andrew; Tolman, Malachi; Thames, Howard D; Withers, Hubert Rodney; Mason, Kathy A; Transtrum, Mark K

2016-12-01

We explore the relationship among experimental design, parameter estimation, and systematic error in sloppy models. We show that the approximate nature of mathematical models poses challenges for experimental design in sloppy models. In many models of complex biological processes it is unknown what are the relevant physical mechanisms that must be included to explain system behaviors. As a consequence, models are often overly complex, with many practically unidentifiable parameters. Furthermore, which mechanisms are relevant/irrelevant vary among experiments. By selecting complementary experiments, experimental design may inadvertently make details that were ommitted from the model become relevant. When this occurs, the model will have a large systematic error and fail to give a good fit to the data. We use a simple hyper-model of model error to quantify a model's discrepancy and apply it to two models of complex biological processes (EGFR signaling and DNA repair) with optimally selected experiments. We find that although parameters may be accurately estimated, the discrepancy in the model renders it less predictive than it was in the sloppy regime where systematic error is small. We introduce the concept of a sloppy system-a sequence of models of increasing complexity that become sloppy in the limit of microscopic accuracy. We explore the limits of accurate parameter estimation in sloppy systems and argue that identifying underlying mechanisms controlling system behavior is better approached by considering a hierarchy of models of varying detail rather than focusing on parameter estimation in a single model.

The Limitations of Model-Based Experimental Design and Parameter Estimation in Sloppy Systems

PubMed Central

Tolman, Malachi; Thames, Howard D.; Mason, Kathy A.

2016-01-01

We explore the relationship among experimental design, parameter estimation, and systematic error in sloppy models. We show that the approximate nature of mathematical models poses challenges for experimental design in sloppy models. In many models of complex biological processes it is unknown what are the relevant physical mechanisms that must be included to explain system behaviors. As a consequence, models are often overly complex, with many practically unidentifiable parameters. Furthermore, which mechanisms are relevant/irrelevant vary among experiments. By selecting complementary experiments, experimental design may inadvertently make details that were ommitted from the model become relevant. When this occurs, the model will have a large systematic error and fail to give a good fit to the data. We use a simple hyper-model of model error to quantify a model’s discrepancy and apply it to two models of complex biological processes (EGFR signaling and DNA repair) with optimally selected experiments. We find that although parameters may be accurately estimated, the discrepancy in the model renders it less predictive than it was in the sloppy regime where systematic error is small. We introduce the concept of a sloppy system–a sequence of models of increasing complexity that become sloppy in the limit of microscopic accuracy. We explore the limits of accurate parameter estimation in sloppy systems and argue that identifying underlying mechanisms controlling system behavior is better approached by considering a hierarchy of models of varying detail rather than focusing on parameter estimation in a single model. PMID:27923060

Application of the Transtheoretical Model of behavior change to the physical activity behavior of WIC mothers.

PubMed

Fahrenwald, Nancy L; Walker, Susan Noble

2003-01-01

This descriptive-correlational study examined the Transtheoretical Model (TTM) of behavior change in relationship to the physical activity behavior of mothers receiving assistance from the Women, Infants, and Children program. A purposive sample (N = 30) of six women at each of the five stages of readiness for behavior change was used. Relationships between stage of behavior change (measured using the Stage of Exercise Adoption tool) and other TTM constructs were examined. The constructs and corresponding instruments included physical activity behavior (Seven-Day Physical Activity Recall), pros, cons, decisional balance (Exercise Benefits/Barriers Scale and two open-ended questions), self-efficacy (Self-efficacy for Exercise scale), and processes of behavior change (Processes of Exercise Adoption tool and the Social Support for Exercise scale). Significant relationships were found between stage of behavior change and two physical activity energy expenditure indices (rs = 0.71-0.73, p < 0.01), daily minutes of moderate to very hard physical activity (rs = 0.81, p < 0.01), pros (rs = 0.56, p < 0.01), cons (rs = -0.52, p < 0.05), decisional balance (rs = 0.56, p < 0.01), and self-efficacy (rs = 0.56, p < 0.01). Use of the 10 processes of change differed by stage of change. Pros to physical activity included a sense of accomplishment, increased strength, stress relief, and getting in shape after pregnancy. Cons included fatigue, childcare, and cold weather. Results support the TTM as relevant to WIC mothers and suggest strategies to increase physical activity in this population.

Reciprocal Relations Between Parents’ Physical Discipline and Children’s Externalizing Behavior During Middle Childhood and Adolescence

PubMed Central

Lansford, Jennifer E.; Criss, Michael M.; Laird, Robert D.; Shaw, Daniel S.; Pettit, Gregory S.; Bates, John E.; Dodge, Kenneth A.

2010-01-01

Using data from two long-term longitudinal projects, we investigated reciprocal relations between maternal reports of physical discipline and teacher and self ratings of child externalizing behavior, accounting for continuity in both discipline and externalizing over time. In Study 1, which followed a community sample of 562 boys and girls from age 6–9, high levels of physical discipline in a given year predicted high levels of externalizing behavior in the next year, and externalizing behavior in a given year predicted high levels of physical discipline in the next year. In Study 2, which followed an independent sample of 290 lower income, higher risk boys from age 10–15, mother-reported physical discipline in a given year predicted child ratings of antisocial behavior in the next year, but child antisocial behavior in a given year did not predict parents’ use of physical discipline in the next year. In neither sample was there evidence that associations between physical discipline and child externalizing changed as the child aged, and findings were not moderated by gender, race, socioeconomic status, or the severity of the physical discipline. Implications for the reciprocal nature of the socialization process and the risks associated with physical discipline are discussed. PMID:21262050

Reciprocal relations between parents' physical discipline and children's externalizing behavior during middle childhood and adolescence.

PubMed

Lansford, Jennifer E; Criss, Michael M; Laird, Robert D; Shaw, Daniel S; Pettit, Gregory S; Bates, John E; Dodge, Kenneth A

2011-02-01

Using data from two long-term longitudinal projects, we investigated reciprocal relations between maternal reports of physical discipline and teacher and self-ratings of child externalizing behavior, accounting for continuity in both discipline and externalizing over time. In Study 1, which followed a community sample of 562 boys and girls from age 6 to 9, high levels of physical discipline in a given year predicted high levels of externalizing behavior in the next year, and externalizing behavior in a given year predicted high levels of physical discipline in the next year. In Study 2, which followed an independent sample of 290 lower income, higher risk boys from age 10 to 15, mother-reported physical discipline in a given year predicted child ratings of antisocial behavior in the next year, but child antisocial behavior in a given year did not predict parents' use of physical discipline in the next year. In neither sample was there evidence that associations between physical discipline and child externalizing changed as the child aged, and findings were not moderated by gender, race, socioeconomic status, or the severity of the physical discipline. Implications for the reciprocal nature of the socialization process and the risks associated with physical discipline are discussed.

Behavioral, normative and control beliefs underlying low-fat dietary and regular physical activity behaviors for adults diagnosed with type 2 diabetes and/or cardiovascular disease.

PubMed

White, Katherine M; Terry, Deborah J; Troup, Carolyn; Rempel, Lynn A

2007-08-01

Promoting healthy lifestyle behaviors is an important aspect of interventions designed to improve the management of chronic diseases such as Type 2 diabetes and cardiovascular disease. The present study used Ajzen's (1991) theory of planned behavior as a framework to examine beliefs amongst adults diagnosed with these conditions who do and do not engage in low-fat dietary and regular physical activity behaviors. Participants (N = 192) completed a questionnaire assessing their behavioral, normative and control beliefs in relation to regular, moderate physical activity and eating foods low in saturated fats. Measures of self-reported behavior were also examined. The findings revealed that, in general, it is the underlying behavioral beliefs that are important determinants for both physical activity and low-fat food consumption with some evidence to suggest that pressure from significant others is an important consideration for low-fat food consumption. Laziness, as a barrier to engaging in physical activity, also emerged as an important factor. To encourage a healthy lifestyle amongst this population, interventions should address the perceived costs associated with behavioral performance and encourage people to maintain healthy behaviors in light of these costs.

Designing collective behavior in a termite-inspired robot construction team.

PubMed

Werfel, Justin; Petersen, Kirstin; Nagpal, Radhika

2014-02-14

Complex systems are characterized by many independent components whose low-level actions produce collective high-level results. Predicting high-level results given low-level rules is a key open challenge; the inverse problem, finding low-level rules that give specific outcomes, is in general still less understood. We present a multi-agent construction system inspired by mound-building termites, solving such an inverse problem. A user specifies a desired structure, and the system automatically generates low-level rules for independent climbing robots that guarantee production of that structure. Robots use only local sensing and coordinate their activity via the shared environment. We demonstrate the approach via a physical realization with three autonomous climbing robots limited to onboard sensing. This work advances the aim of engineering complex systems that achieve specific human-designed goals.

Transitions between superstatistical regimes: Validity, breakdown and applications

NASA Astrophysics Data System (ADS)

Jizba, Petr; Korbel, Jan; Lavička, Hynek; Prokš, Martin; Svoboda, Václav; Beck, Christian

2018-03-01

Superstatistics is a widely employed tool of non-equilibrium statistical physics which plays an important rôle in analysis of hierarchical complex dynamical systems. Yet, its "canonical" formulation in terms of a single nuisance parameter is often too restrictive when applied to complex empirical data. Here we show that a multi-scale generalization of the superstatistics paradigm is more versatile, allowing to address such pertinent issues as transmutation of statistics or inter-scale stochastic behavior. To put some flesh on the bare bones, we provide a numerical evidence for a transition between two superstatistics regimes, by analyzing high-frequency (minute-tick) data for share-price returns of seven selected companies. Salient issues, such as breakdown of superstatistics in fractional diffusion processes or connection with Brownian subordination are also briefly discussed.

Change in physical education motivation and physical activity behavior during middle school.

PubMed

Cox, Anne E; Smith, Alan L; Williams, Lavon

2008-11-01

To test a mediational model of the relationships among motivation-related variables in middle-school physical education and leisure-time physical activity behavior. Sixth- and seventh-grade physical education students from five middle schools in the midwest United States completed a survey containing measures of study variables on two occasions, 1 year apart. Motivation-related constructs positively predicted leisure-time physical activity behavior. Enjoyment of activities in physical education and physical activity during class mediated the relationship between self-determined motivation in physical education and leisure-time physical activity. Perceived competence, autonomy, and relatedness were important antecedent variables in the model, with autonomy and relatedness showing less stability over time and positively predicting self-determined motivation. Students' leisure-time physical activity is linked to motivation-related experiences in physical education. Perceptions of competence, autonomy, and relatedness, self-determined motivation, enjoyment, and physical activity in the physical education setting directly or indirectly predict leisure-time physical activity. The associations suggest that more adaptive motivation corresponds to transfer of behavior across contexts. Also, the findings suggest that the efficacy of school-based physical activity interventions, within and outside of school, is linked to the degree of support for students' self-determined motivation.

Correlates of US adult physical activity and sedentary behavior patterns.

PubMed

Jones, Sydney A; Wen, Fang; Herring, Amy H; Evenson, Kelly R

2016-12-01

Physical activity and sedentary behavior patterns may be differentially associated with socio-demographic and health measures. We explored correlates of day-to-day patterns over a week in accelerometer measured physical activity and sedentary behavior to inform intervention development. Cross-sectional study. National Health and Nutrition Examination Survey (NHANES) adult participants (≥20 years) in 2003-2006 wore an accelerometer for 1 week. Accelerometer data from 7236 participants were used to derive latent classes describing day-to-day patterns over a week of physical activity and sedentary behavior. Correlates of each pattern were identified using multinomial logistic regression from 21 potential variables grouped into four domains: socio-demographic, acculturation, cardiovascular, and health history. Older age, female sex, higher body mass index, and history of chronic disease were consistently associated with lower odds of being in a more active compared to the least active class. In contrast, being employed, speaking Spanish at home, and having better self-rated health were associated with higher odds of being in a more active compared to the least active class. Correlates of physical activity and sedentary behavior patterns were identified from all domains (socio-demographic, acculturation, cardiovascular, and health history). Most correlates that were positively associated with physical activity were negatively associated with sedentary behavior. Better understanding of the correlates of physical activity and sedentary behavior patterns can inform interventions to promote physical activity and reduce sedentary behavior. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Physical activity behavior and role overload in mothers.

PubMed

Lovell, Geoff P; Butler, Frances R

2015-01-01

We examined physical activity stages of change, physical activity behavior, and role overload in different stages of motherhood in a predominantly Australian sample. Neither physical activity behavior, stages of physical activity change, nor role overload significantly differed across motherhood groups. Role overload was significantly higher for mothers in the contemplation, planning, and action stages of physical activity than in the maintenance stage of change. Role overload had a weak, although significant, negative correlation with leisure-time physical activity. We conclude that strategies focused upon reducing role overload or perceived role overload have only limited potential to meaningfully increase leisure-time physical activity in mothers.

Physical aggressive resident behavior during hygienic care.

PubMed

Farrell Miller, M

1997-05-01

Management of aggressive behavior has been identified as a concern for nursing staff who provide institutional care for cognitively impaired elderly. The Omnibus Reconciliation Act (OBRA '87) mandates a trial reduction in the use of chemical and physical restraints, and the development of nursing interventions for the management of behavioral disorders of institutionalized cognitively impaired elderly. Most skilled nursing facilities, however, are limited in their ability to provide environmental and behavioral programs to manage aggressive patient behavior. For the purposes of this study, physically aggressive behavior was identified as threatened or actual aggressive patient contact which has taken place between a patient and a member of the nursing staff. This study explored the nursing staff's responses to patient physical aggression and the effects that physical aggression had on them and on nursing practice from the perspective of the nursing staff. Nursing staff employed on one Dementia Special Care Unit (DSCU) were invited to participate. Interviews with nursing staff were analyzed using qualitative descriptive methods described by Miles and Huberman (1994). Nursing staff reported that they were subjected to aggressive patient behaviors ranging from verbal threats to actual physical violence. Nursing staff reported that showering a resident was the activity of daily living most likely to provoke patient to staff physical aggression. The findings revealed geropsychiatric nursing practices for the management of physically aggressive residents, and offered recommendations for improving the safety of nursing staff and residents on a secured DSCU.

Physical inactivity and sedentary behavior: Overlooked risk factors in autoimmune rheumatic diseases?

PubMed

Pinto, Ana Jéssica; Roschel, Hamilton; de Sá Pinto, Ana Lúcia; Lima, Fernanda Rodrigues; Pereira, Rosa Maria Rodrigues; Silva, Clovis Artur; Bonfá, Eloisa; Gualano, Bruno

2017-07-01

This review aims to (1) summarize the estimates of physical inactivity and sedentary behavior in autoimmune rheumatic diseases; (2) describe the relationship between physical (in)activity levels and disease-related outcomes; (3) contextualize the estimates and impact of physical inactivity and sedentary behavior in autoimmune diseases compared to other rheumatic diseases and chronic conditions; and (4) discuss scientific perspectives around this theme and potential clinical interventions to attenuate these preventable risk factors. We compiled evidence to show that estimates of physical inactivity and sedentary behavior in autoimmune rheumatic diseases are generally comparable to other rheumatic diseases as well as to other chronic conditions (e.g., type 2 diabetes, cardiovascular diseases, and obesity), in which a lack of physical activity and excess of sedentary behavior are well-known predictors of morbimortality. In addition, we also showed evidence that both physical inactivity and sedentary behavior may be associated with poor health-related outcomes (e.g., worse disease symptoms and low functionality) in autoimmune rheumatic diseases. Thus, putting into practice interventions to make the patients "sit less and move more", particularly light-intensity activities and/or breaking-up sedentary time, is a simple and prudent therapeutic approach to minimize physical inactivity and sedentary behavior, which are overlooked yet modifiable risk factors in the field of autoimmune rheumatic diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Active lifestyles in older adults: an integrated predictive model of physical activity and exercise

PubMed Central

Galli, Federica; Chirico, Andrea; Mallia, Luca; Girelli, Laura; De Laurentiis, Michelino; Lucidi, Fabio; Giordano, Antonio; Botti, Gerardo

2018-01-01

Physical activity and exercise have been identified as behaviors to preserve physical and mental health in older adults. The aim of the present study was to test the Integrated Behavior Change model in exercise and physical activity behaviors. The study evaluated two different samples of older adults: the first engaged in exercise class, the second doing spontaneous physical activity. The key analyses relied on Variance-Based Structural Modeling, which were performed by means of WARP PLS 6.0 statistical software. The analyses estimated the Integrated Behavior Change model in predicting exercise and physical activity, in a longitudinal design across two months of assessment. The tested models exhibited a good fit with the observed data derived from the model focusing on exercise, as well as with those derived from the model focusing on physical activity. Results showed, also, some effects and relations specific to each behavioral context. Results may form a starting point for future experimental and intervention research. PMID:29875997

Cognitive control in the self-regulation of physical activity and sedentary behavior

PubMed Central

Buckley, Jude; Cohen, Jason D.; Kramer, Arthur F.; McAuley, Edward; Mullen, Sean P.

2014-01-01

Cognitive control of physical activity and sedentary behavior is receiving increased attention in the neuroscientific and behavioral medicine literature as a means of better understanding and improving the self-regulation of physical activity. Enhancing individuals’ cognitive control capacities may provide a means to increase physical activity and reduce sedentary behavior. First, this paper reviews emerging evidence of the antecedence of cognitive control abilities in successful self-regulation of physical activity, and in precipitating self-regulation failure that predisposes to sedentary behavior. We then highlight the brain networks that may underpin the cognitive control and self-regulation of physical activity, including the default mode network, prefrontal cortical networks and brain regions and pathways associated with reward. We then discuss research on cognitive training interventions that document improved cognitive control and that suggest promise of influencing physical activity regulation. Key cognitive training components likely to be the most effective at improving self-regulation are also highlighted. The review concludes with suggestions for future research. PMID:25324754

Multiscale Characterization of Bacterial Swarming Illuminates Principles Governing Directed Surface Motility

NASA Astrophysics Data System (ADS)

Strickland, Ben; Hoeger, Kentaro; Ursell, Tristan

In many systems, individual characteristics interact, leading to the spontaneous emergence of order and complexity. In biological settings like microbes, such collective behaviors can imbue a variety of benefits to constituent individuals, including increased spatial range, improved access to nutrients, and enhanced resistance to antibiotic threats. To untangle the biophysical underpinnings of collective motility, we use passive tracers and a curated genetic library of Bacillus subtilis, including motile, non-motile, biofilm-deficient, and non-chemotactic mutants. We characterize and connect individual behavior on the microscopic scale to macroscopic colony morphology and motility of dendritic swarming. We analyze the persistence and dynamics of coordinated movement on length scales up to 4 orders of magnitude larger than that of individual cells, revealing rapid and directed responses of microbial groups to external stimuli, such as avoidance dynamics across chemical gradients. Our observations uncover the biophysical interplay between individual motility, surface wetness, phenotypic diversity, and external physical forces that robustly precipitate coordinated group behavior in microbes, and suggest general principles that govern the transition from individual to group behavior.

Beyond synergies. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

NASA Astrophysics Data System (ADS)

Schwartz, Andrew B.

2016-07-01

The target paper by Santello et al. [1] uses the observation that hand shape during grasping can be described by a small set of basic postures, or ;synergies,; to describe the possible neural basis of motor control during this complex behavior. In the literature, the term ;synergy; has been used with a number of different meanings and is still loosely defined, making it difficult to derive concrete analogs of corresponding neural structure. Here, I will define ;synergy; broadly, as a set of parameters bound together by a pattern of correlation. With this definition, it can be argued that behavioral synergies are just one facet of the correlational structuring used by the brain to generate behavior. As pointed out in the target article, the structure found in synergies is driven by the physical constraints of our bodies and our surroundings, combined with the behavioral control imparted by our nervous system. This control itself is based on correlational structure which is likely to be a fundamental property of brain function.

Neuromodulation of Nestmate Recognition Decisions by Pavement Ants.

PubMed

Bubak, Andrew N; Yaeger, Jazmine D W; Renner, Kenneth J; Swallow, John G; Greene, Michael J

2016-01-01

Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context-isolation, nestmate interaction, or fighting non-nestmates-affects brain monoamine levels in pavement ants (Tetramorium caespitum). Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants.

Neuromodulation of Nestmate Recognition Decisions by Pavement Ants

PubMed Central

Bubak, Andrew N.; Yaeger, Jazmine D. W.; Renner, Kenneth J.; Swallow, John G.; Greene, Michael J.

2016-01-01

Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context—isolation, nestmate interaction, or fighting non-nestmates—affects brain monoamine levels in pavement ants (Tetramorium caespitum). Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants. PMID:27846261