Visualizing the dynamic structure of the plant photosynthetic membrane.

PubMed

Ruban, Alexander V; Johnson, Matthew P

2015-11-03

The chloroplast thylakoid membrane is the site for the initial steps of photosynthesis that convert solar energy into chemical energy, ultimately powering almost all life on earth. The heterogeneous distribution of protein complexes within the membrane gives rise to an intricate three-dimensional structure that is nonetheless extremely dynamic on a timescale of seconds to minutes. These dynamics form the basis for the regulation of photosynthesis, and therefore the adaptability of plants to different environments. High-resolution microscopy has in recent years begun to provide new insights into the structural dynamics underlying a number of regulatory processes such as membrane stacking, photosystem II repair, photoprotective energy dissipation, state transitions and alternative electron transfer. Here we provide an overview of the essentials of thylakoid membrane structure in plants, and consider how recent advances, using a range of microscopies, have substantially increased our knowledge of the thylakoid dynamic structure. We discuss both the successes and limitations of the currently available techniques and highlight newly emerging microscopic methods that promise to move the field beyond the current 'static' view of membrane organization based on frozen snapshots to a 'live' view of functional membranes imaged under native aqueous conditions at ambient temperature and responding dynamically to external stimuli.

Imaging multi-scale dynamics in vivo with spiral volumetric optoacoustic tomography

NASA Astrophysics Data System (ADS)

Deán-Ben, X. Luís.; Fehm, Thomas F.; Ford, Steven J.; Gottschalk, Sven; Razansky, Daniel

2017-03-01

Imaging dynamics in living organisms is essential for the understanding of biological complexity. While multiple imaging modalities are often required to cover both microscopic and macroscopic spatial scales, dynamic phenomena may also extend over different temporal scales, necessitating the use of different imaging technologies based on the trade-off between temporal resolution and effective field of view. Optoacoustic (photoacoustic) imaging has been shown to offer the exclusive capability to link multiple spatial scales ranging from organelles to entire organs of small animals. Yet, efficient visualization of multi-scale dynamics remained difficult with state-of-the-art systems due to inefficient trade-offs between image acquisition and effective field of view. Herein, we introduce a spiral volumetric optoacoustic tomography (SVOT) technique that provides spectrally-enriched high-resolution optical absorption contrast across multiple spatio-temporal scales. We demonstrate that SVOT can be used to monitor various in vivo dynamics, from video-rate volumetric visualization of cardiac-associated motion in whole organs to high-resolution imaging of pharmacokinetics in larger regions. The multi-scale dynamic imaging capability thus emerges as a powerful and unique feature of the optoacoustic technology that adds to the multiple advantages of this technology for structural, functional and molecular imaging.

Intercultural Awareness: Modelling an Understanding of Cultures in Intercultural Communication through English as a Lingua Franca

ERIC Educational Resources Information Center

Baker, Will

2011-01-01

The use of English as a global lingua franca (ELF) raises challenges concerning how we understand the relationship between languages and cultures in intercultural communication. In the dynamic contexts of ELF this relationship needs to be viewed as situated and emergent entailing a new approach to understanding intercultural competence in…

Exploring Migratory Dynamics on HIV Transmission: The Case of Mexicans in New York City and Puebla, Mexico

PubMed Central

Guilamo-Ramos, Vincent; McCarthy, Katharine; Muñoz-Laboy, Miguel A.; de Lourdes Rosas López, Maria

2014-01-01

Migration and population movement are increasingly viewed as important factors associated with HIV transmission risk. With growing awareness of the potential impact of migration on HIV transmission, several perspectives have emerged that posit differing dynamics of risk. We considered available data on the role of migration on HIV transmission among Mexican migrants in New York City and Puebla, Mexico. Specifically, we examined 3 distinct models of migratory dynamics of HIV transmission—namely, the structural model, the local contextual model, and the interplay model. In doing so, we reframed current public health perspectives on the role of migration on HIV transmission. PMID:24825203

Storyline Visualizations of Eye Tracking of Movie Viewing

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

Balint, John T.; Arendt, Dustin L.; Blaha, Leslie M.

Storyline visualizations offer an approach that promises to capture the spatio-temporal characteristics of individual observers and simultaneously illustrate emerging group behaviors. We develop a visual analytics approach to parsing, aligning, and clustering fixation sequences from eye tracking data. Visualization of the results captures the similarities and differences across a group of observers performing a common task. We apply our storyline approach to visualize gaze patterns of people watching dynamic movie clips. Storylines mitigate some of the shortcomings of existent spatio-temporal visualization techniques and, importantly, continue to highlight individual observer behavioral dynamics.

The Family as a Living Open System: An Emerging Conceptual Framework.

ERIC Educational Resources Information Center

Fawcett, Jacqueline

The conceptual framework of the family presented in this paper views the family as a reality in itself. The four-dimensional energy field that is the family system is a living open system, a dynamic whole engaged in mutual and simultaneous interaction with a four-dimensional energy field that is the environment. The family system is patterned and…

From Contextual Fear to a Dynamic View of Memory Systems

PubMed Central

Fanselow, Michael S

2009-01-01

The brain does not learn and remember in a unitary fashion. Rather, different circuits specialize in certain classes of problems and encode different types of information. Damage to one of these systems typically results in amnesia only for the form of memory that is the affected region's specialty. How does the brain allocate a specific category of memory to a particular circuit? This question has received little attention. The currently dominant view, Multiple Memory Systems Theory, assumes that such abilities are hard-wired. Using fear conditioning as a paradigmatic case, I propose an alternative model in which mnemonic processing is allocated to specific circuits through a dynamic process. Potential circuits compete to form memories with the most efficient circuits emerging as winners. However, alternate circuits compensate when these “primary” circuits are compromised. PMID:19939724

Coordination Dynamics in Cognitive Neuroscience

PubMed Central

Bressler, Steven L.; Kelso, J. A. Scott

2016-01-01

Many researchers and clinicians in cognitive neuroscience hold to a modular view of cognitive function in which the cerebral cortex operates by the activation of areas with circumscribed elementary cognitive functions. Yet an ongoing paradigm shift to a dynamic network perspective is underway. This new viewpoint treats cortical function as arising from the coordination dynamics within and between cortical regions. Cortical coordination dynamics arises due to the unidirectional influences imposed on a cortical area by inputs from other areas that project to it, combined with the projection reciprocity that characterizes cortical connectivity and gives rise to reentrant processing. As a result, cortical dynamics exhibits both segregative and integrative tendencies and gives rise to both cooperative and competitive relations within and between cortical areas that are hypothesized to underlie the emergence of cognition in brains. PMID:27695395

The Role of Time-Scales in Socio-hydrology

NASA Astrophysics Data System (ADS)

Blöschl, Günter; Sivapalan, Murugesu

2016-04-01

Much of the interest in hydrological modeling in the past decades revolved around resolving spatial variability. With the rapid changes brought about by human impacts on the hydrologic cycle, there is now an increasing need to refocus on time dependency. We present a co-evolutionary view of hydrologic systems, in which every part of the system including human systems, co-evolve, albeit at different rates. The resulting coupled human-nature system is framed as a dynamical system, characterized by interactions of fast and slow time scales and feedbacks between environmental and social processes. This gives rise to emergent phenomena such as the levee effect, adaptation to change and system collapse due to resource depletion. Changing human values play a key role in the emergence of these phenomena and should therefore be considered as internal to the system in a dynamic way. The co-evolutionary approach differs from the traditional view of water resource systems analysis as it allows for path dependence, multiple equilibria, lock-in situations and emergent phenomena. The approach may assist strategic water management for long time scales through facilitating stakeholder participation, exploring the possibility space of alternative futures, and helping to synthesise the observed dynamics of different case studies. Future research opportunities include the study of how changes in human values are connected to human-water interactions, historical analyses of trajectories of system co-evolution in individual places and comparative analyses of contrasting human-water systems in different climate and socio-economic settings. Reference Sivapalan, M. and G. Blöschl (2015) Time scale interactions and the coevolution of humans and water. Water Resour. Res., 51, 6988-7022, doi:10.1002/2015WR017896.

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

NASA Astrophysics Data System (ADS)

Bloeschl, G.; Sivapalan, M.

2015-12-01

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

Human dynamics in repurchase behavior based on comments mining

NASA Astrophysics Data System (ADS)

Yang, Tian; Feng, Xin; Wu, Ye; Wang, Shengfeng; Xiao, Jinghua

2018-07-01

Hundreds of thousands of individual deals and comments are analyzed to ask: what kinds of patterns appear in their repurchase process? Our results suggest that, in the empirical description, the intervals between two consecutive purchases obey a power-law distribution. Notwithstanding a wide range of individual preferences, shoppers' repurchase behaviors show some similar patterns, called long-scale quiet and short-scale emergence, and the alternating appearance of them form an endless chain in repurchase. In agreement with the empirical results, these short-scale and long-scale patterns suggest an adaptive model with alterable exponents complying with a power-law distribution. And it also implies that each user behaves his own intrinsic pattern such as unique repurchase intensity and silence-emergence cycle, which contributes to customer life-time value from the new view of dynamics and repurchase cycles.

Reciprocity, Punishment, Institutions: The Streets to Social Collaboration -- New Theories on How Emerging Social Artifacts Control Our Lives in Society

NASA Astrophysics Data System (ADS)

Gerace, Giuliana

What mechanisms induce and support cooperation in social interaction? Traditional rational-choice perspective has resulted ineffective to keep track of complex real-world dynamics of cooperation. On the other hand, perspectives based on the justification of fairness preferences as internalized behavioural forces driving realistic cooperative interactions are notoriously incomplete and rather fuzzy with respect to their theoretical foundations. After considering recognized evolutionary accounts of the emergence and resilience of social standards, we endorse the view according to which the key to understanding evolutionary dynamics of social engagement is to be found in individual motivational attitudes to interaction. But, beyond any psychological implications, we suggest not exiting from the "logic of reciprocity" in considering the rationality of preferences for social interaction. Preliminary supporting experimental evidence is provided.

The development of imitation in infancy

PubMed Central

Jones, Susan S.

2009-01-01

An overview of existing data on imitation in infancy suggests that changes in the direction of imitation research are underway. The widely accepted view that newborn infants imitate lacks supporting evidence. Instead, existing data suggest that infants do not imitate others until their second year, and that imitation of different kinds of behaviour emerges at different ages. The evidence is consistent with a dynamic systems account in which the ability to imitate is not an inherited, specialized module, but is instead the emergent product of a system of social, cognitive and motor components, each with its own developmental history. PMID:19620104

Subcultural evolution and illicit drug use*

PubMed Central

GOLUB, ANDREW; JOHNSON, BRUCE D.; DUNLAP, ELOISE

2011-01-01

This article articulates a subcultural basis to the evolving popularity for different illicit drugs primarily based on empirical research in the United States, especially among inner-city populations. From this perspective, drug use emerges from a dialectic between drug subcultures with individual identity development. The prevailing culture and subcultures affect drugs’ popularity by imparting significance to their use. Innovations, historical events, and individual choices can cause subcultures to emerge and change over time. This subcultural view provides insight into the widespread use of licit drug, the dynamics of drug eras (or epidemics), the formation of drug generations, and the apparent “gateway” phenomenon. PMID:23805068

Multidrug-resistant tuberculosis (MDR-TB) in India: an attempt to link biosocial determinants.

PubMed

Atre, Sachin R; Mistry, Nerges F

2005-04-01

Multidrug-resistant tuberculosis (MDR-TB) has emerged as a possible threat to global tuberculosis control efforts in recent years. It is a challenge not only from a public health point of view but also in the context of global economy, especially in the absence of treatment for MDR-TB at national-level programs in developing countries. Biological accounts are insufficient to understand the emergence and dynamics of drug resistance. This article focuses essentially on the need for a holistic perspective, linking biosocial determinants that would probably lead to better insights into MDR-TB control strategies.

Public Health Threat of New, Reemerging, and Neglected Zoonoses in the Industrialized World

PubMed Central

Cutler, Sally J.; Fooks, Anthony R.

2010-01-01

Microbiologic infections acquired from animals, known as zoonoses, pose a risk to public health. An estimated 60% of emerging human pathogens are zoonotic. Of these pathogens, >71% have wildlife origins. These pathogens can switch hosts by acquiring new genetic combinations that have altered pathogenic potential or by changes in behavior or socioeconomic, environmental, or ecologic characteristics of the hosts. We discuss causal factors that influence the dynamics associated with emergence or reemergence of zoonoses, particularly in the industrialized world, and highlight selected examples to provide a comprehensive view of their range and diversity. PMID:20031035

Learning to recognize objects on the fly: a neurally based dynamic field approach.

PubMed

Faubel, Christian; Schöner, Gregor

2008-05-01

Autonomous robots interacting with human users need to build and continuously update scene representations. This entails the problem of rapidly learning to recognize new objects under user guidance. Based on analogies with human visual working memory, we propose a dynamical field architecture, in which localized peaks of activation represent objects over a small number of simple feature dimensions. Learning consists of laying down memory traces of such peaks. We implement the dynamical field model on a service robot and demonstrate how it learns 30 objects from a very small number of views (about 5 per object are sufficient). We also illustrate how properties of feature binding emerge from this framework.

Eavesdropping on altered cell-to-cell signaling in cancer by secretome profiling.

PubMed

Klinke, David J

2016-01-01

In the past decade, cumulative clinical experiences with molecular targeted therapies and immunotherapies for cancer have promoted a shift in our conceptual understanding of cancer. This view shifted from viewing solid tumors as a homogeneous mass of malignant cells to viewing tumors as heterogeneous structures that are dynamically shaped by intercellular interactions among the variety of stromal, immune, and malignant cells present within the tumor microenvironment. As in any dynamic system, identifying how cells communicate to maintain homeostasis and how this communication is altered during oncogenesis are key hurdles for developing therapies to restore normal tissue homeostasis. Here, I discuss tissues as dynamic systems, using the mammary gland as an example, and the evolutionary concepts applied to oncogenesis. Drawing from these concepts, I present 2 competing hypotheses for how intercellular communication might be altered during oncogenesis. As an initial test of these competing hypotheses, a recent secretome comparison between normal human mammary and HER2+ breast cancer cell lines suggested that the particular proteins secreted by the malignant cells reflect a convergent evolutionary path associated with oncogenesis in a specific anatomical niche, despite arising in different individuals. Overall, this study illustrates the emerging power of secretome proteomics to probe, in an unbiased way, how intercellular communication changes during oncogenesis.

Eavesdropping on altered cell-to-cell signaling in cancer by secretome profiling

PubMed Central

Klinke, David J

2016-01-01

In the past decade, cumulative clinical experiences with molecular targeted therapies and immunotherapies for cancer have promoted a shift in our conceptual understanding of cancer. This view shifted from viewing solid tumors as a homogeneous mass of malignant cells to viewing tumors as heterogeneous structures that are dynamically shaped by intercellular interactions among the variety of stromal, immune, and malignant cells present within the tumor microenvironment. As in any dynamic system, identifying how cells communicate to maintain homeostasis and how this communication is altered during oncogenesis are key hurdles for developing therapies to restore normal tissue homeostasis. Here, I discuss tissues as dynamic systems, using the mammary gland as an example, and the evolutionary concepts applied to oncogenesis. Drawing from these concepts, I present 2 competing hypotheses for how intercellular communication might be altered during oncogenesis. As an initial test of these competing hypotheses, a recent secretome comparison between normal human mammary and HER2+ breast cancer cell lines suggested that the particular proteins secreted by the malignant cells reflect a convergent evolutionary path associated with oncogenesis in a specific anatomical niche, despite arising in different individuals. Overall, this study illustrates the emerging power of secretome proteomics to probe, in an unbiased way, how intercellular communication changes during oncogenesis. PMID:27308541

Understanding viral video dynamics through an epidemic modelling approach

NASA Astrophysics Data System (ADS)

Sachak-Patwa, Rahil; Fadai, Nabil T.; Van Gorder, Robert A.

2018-07-01

Motivated by the hypothesis that the spread of viral videos is analogous to the spread of a disease epidemic, we formulate a novel susceptible-exposed-infected-recovered-susceptible (SEIRS) delay differential equation epidemic model to describe the popularity evolution of viral videos. Our models incorporate time-delay, in order to accurately describe the virtual contact process between individuals and the temporary immunity of individuals to videos after they have grown tired of watching them. We validate our models by fitting model parameters to viewing data from YouTube music videos, in order to demonstrate that the model solutions accurately reproduce real behaviour seen in this data. We use an SEIR model to describe the initial growth and decline of daily views, and an SEIRS model to describe the long term behaviour of the popularity of music videos. We also analyse the decay rates in the daily views of videos, determining whether they follow a power law or exponential distribution. Although we focus on viral videos, the modelling approach may be used to understand dynamics emergent from other areas of science which aim to describe consumer behaviour.

Display of high dynamic range images under varying viewing conditions

NASA Astrophysics Data System (ADS)

Borer, Tim

2017-09-01

Recent demonstrations of high dynamic range (HDR) television have shown that superb images are possible. With the emergence of an HDR television production standard (ITU-R Recommendation BT.2100) last year, HDR television production is poised to take off. However research to date has focused principally on HDR image display only under "dark" viewing conditions. HDR television will need to be displayed at varying brightness and under varying illumination (for example to view sport in daytime or on mobile devices). We know, from common practice with conventional TV, that the rendering intent (gamma) should change under brighter conditions, although this is poorly quantified. For HDR the need to render images under varying conditions is all the more acute. This paper seeks to explore the issues surrounding image display under varying conditions. It also describes how visual adaptation is affected by display brightness, surround illumination, screen size and viewing distance. Existing experimental results are presented and extended to try to quantify these effects. Using the experimental results it is described how HDR images may be displayed so that they are perceptually equivalent under different viewing conditions. A new interpretation of the experimental results is reported, yielding a new, luminance invariant model for the appropriate display "gamma". In this way the consistency of HDR image reproduction should be improved, thereby better maintaining "creative intent" in television.

The dynamics of the RNA world: insights and challenges.

PubMed

Kun, Ádám; Szilágyi, András; Könnyű, Balázs; Boza, Gergely; Zachar, István; Szathmáry, Eörs

2015-04-01

The RNA world hypothesis of the origin of life, in which RNA emerged as both enzyme and information carrier, is receiving solid experimental support. The prebiotic synthesis of biomolecules, the catalytic aid offered by mineral surfaces, and the vast enzymatic repertoire of ribozymes are only pieces of the origin of life puzzle; the full picture can only emerge if the pieces fit together by either following from one another or coexisting with each other. Here, we review the theory of the origin, maintenance, and enhancement of the RNA world as an evolving population of dynamical systems. The dynamical view of the origin of life allows us to pinpoint the missing and the not fitting pieces: (1) How can the first self-replicating ribozyme emerge in the absence of template-directed information replication? (2) How can nucleotide replicators avoid competitive exclusion despite utilizing the very same resources (nucleobases)? (3) How can the information catastrophe be avoided? (4) How can enough genes integrate into a cohesive system in order to transition to a cellular stage? (5) How can the way information is stored and metabolic complexity coevolve to pave to road leading out of the RNA world to the present protein-DNA world? © 2015 New York Academy of Sciences.

Population and Environment

PubMed Central

de Sherbinin, Alex; Carr, David; Cassels, Susan; Jiang, Leiwen

2009-01-01

The interactions between human population dynamics and the environment have often been viewed mechanistically. This review elucidates the complexities and contextual specificities of population-environment relationships in a number of domains. It explores the ways in which demographers and other social scientists have sought to understand the relationships among a full range of population dynamics (e.g., population size, growth, density, age and sex composition, migration, urbanization, vital rates) and environmental changes. The chapter briefly reviews a number of the theories for understanding population and the environment and then proceeds to provide a state-of-the-art review of studies that have examined population dynamics and their relationship to five environmental issue areas. The review concludes by relating population-environment research to emerging work on human-environment systems. PMID:20011237

Time, space, and disorder in the expanding proteome universe.

PubMed

Minde, David-Paul; Dunker, A Keith; Lilley, Kathryn S

2017-04-01

Proteins are highly dynamic entities. Their myriad functions require specific structures, but proteins' dynamic nature ranges all the way from the local mobility of their amino acid constituents to mobility within and well beyond single cells. A truly comprehensive view of the dynamic structural proteome includes: (i) alternative sequences, (ii) alternative conformations, (iii) alternative interactions with a range of biomolecules, (iv) cellular localizations, (v) alternative behaviors in different cell types. While these aspects have traditionally been explored one protein at a time, we highlight recently emerging global approaches that accelerate comprehensive insights into these facets of the dynamic nature of protein structure. Computational tools that integrate and expand on multiple orthogonal data types promise to enable the transition from a disjointed list of static snapshots to a structurally explicit understanding of the dynamics of cellular mechanisms. © 2017 The Authors. Proteomics Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Price Equation, Gradient Dynamics, and Continuous Trait Game Theory.

PubMed

Lehtonen, Jussi

2018-01-01

A recent article convincingly nominated the Price equation as the fundamental theorem of evolution and used it as a foundation to derive several other theorems. A major section of evolutionary theory that was not addressed is that of game theory and gradient dynamics of continuous traits with frequency-dependent fitness. Deriving fundamental results in these fields under the unifying framework of the Price equation illuminates similarities and differences between approaches and allows a simple, unified view of game-theoretical and dynamic concepts. Using Taylor polynomials and the Price equation, I derive a dynamic measure of evolutionary change, a condition for singular points, the convergence stability criterion, and an alternative interpretation of evolutionary stability. Furthermore, by applying the Price equation to a multivariable Taylor polynomial, the direct fitness approach to kin selection emerges. Finally, I compare these results to the mean gradient equation of quantitative genetics and the canonical equation of adaptive dynamics.

Toward the Darwinian transition: Switching between distributed and speciated states in a simple model of early life.

PubMed

Arnoldt, Hinrich; Strogatz, Steven H; Timme, Marc

2015-01-01

It has been hypothesized that in the era just before the last universal common ancestor emerged, life on earth was fundamentally collective. Ancient life forms shared their genetic material freely through massive horizontal gene transfer (HGT). At a certain point, however, life made a transition to the modern era of individuality and vertical descent. Here we present a minimal model for stochastic processes potentially contributing to this hypothesized "Darwinian transition." The model suggests that HGT-dominated dynamics may have been intermittently interrupted by selection-driven processes during which genotypes became fitter and decreased their inclination toward HGT. Stochastic switching in the population dynamics with three-point (hypernetwork) interactions may have destabilized the HGT-dominated collective state and essentially contributed to the emergence of vertical descent and the first well-defined species in early evolution. A systematic nonlinear analysis of the stochastic model dynamics covering key features of evolutionary processes (such as selection, mutation, drift and HGT) supports this view. Our findings thus suggest a viable direction out of early collective evolution, potentially enabling the start of individuality and vertical Darwinian evolution.

Copper signaling in the brain and beyond.

PubMed

Ackerman, Cheri M; Chang, Christopher J

2018-03-30

Transition metals have been recognized and studied primarily in the context of their essential roles as structural and metabolic cofactors for biomolecules that compose living systems. More recently, an emerging paradigm of transition-metal signaling, where dynamic changes in transitional metal pools can modulate protein function, cell fate, and organism health and disease, has broadened our view of the potential contributions of these essential nutrients in biology. Using copper as a canonical example of transition-metal signaling, we highlight key experiments where direct measurement and/or visualization of dynamic copper pools, in combination with biochemical, physiological, and behavioral studies, have deciphered sources, targets, and physiological effects of copper signals.

Learning of embodied interaction dynamics with recurrent neural networks: some exploratory experiments.

PubMed

Oubbati, Mohamed; Kord, Bahram; Koprinkova-Hristova, Petia; Palm, Günther

2014-04-01

The new tendency of artificial intelligence suggests that intelligence must be seen as a result of the interaction between brains, bodies and environments. This view implies that designing sophisticated behaviour requires a primary focus on how agents are functionally coupled to their environments. Under this perspective, we present early results with the application of reservoir computing as an efficient tool to understand how behaviour emerges from interaction. Specifically, we present reservoir computing models, that are inspired by imitation learning designs, to extract the essential components of behaviour that results from agent-environment interaction dynamics. Experimental results using a mobile robot are reported to validate the learning architectures.

Learning of embodied interaction dynamics with recurrent neural networks: some exploratory experiments

NASA Astrophysics Data System (ADS)

Oubbati, Mohamed; Kord, Bahram; Koprinkova-Hristova, Petia; Palm, Günther

2014-04-01

The new tendency of artificial intelligence suggests that intelligence must be seen as a result of the interaction between brains, bodies and environments. This view implies that designing sophisticated behaviour requires a primary focus on how agents are functionally coupled to their environments. Under this perspective, we present early results with the application of reservoir computing as an efficient tool to understand how behaviour emerges from interaction. Specifically, we present reservoir computing models, that are inspired by imitation learning designs, to extract the essential components of behaviour that results from agent-environment interaction dynamics. Experimental results using a mobile robot are reported to validate the learning architectures.

Dynamic Contact Angle at the Nanoscale: A Unified View.

PubMed

Lukyanov, Alex V; Likhtman, Alexei E

2016-06-28

Generation of a dynamic contact angle in the course of wetting is a fundamental phenomenon of nature. Dynamic wetting processes have a direct impact on flows at the nanoscale, and therefore, understanding them is exceptionally important to emerging technologies. Here, we reveal the microscopic mechanism of dynamic contact angle generation. It has been demonstrated using large-scale molecular dynamics simulations of bead-spring model fluids that the main cause of local contact angle variations is the distribution of microscopic force acting at the contact line region. We were able to retrieve this elusive force with high accuracy. It has been directly established that the force distribution can be solely predicted on the basis of a general friction law for liquid flow at solid surfaces by Thompson and Troian. The relationship with the friction law provides both an explanation of the phenomenon of dynamic contact angle and a methodology for future predictions. The mechanism is intrinsically microscopic, universal, and irreducible and is applicable to a wide range of problems associated with wetting phenomena.

Emergent dynamics of spiking neurons with fluctuating threshold

NASA Astrophysics Data System (ADS)

Bhattacharjee, Anindita; Das, M. K.

2017-05-01

Role of fluctuating threshold on neuronal dynamics is investigated. The threshold function is assumed to follow a normal probability distribution. Standard deviation of inter-spike interval of the response is computed as an indicator of irregularity in spike emission. It has been observed that, the irregularity in spiking is more if the threshold variation is more. A significant change in modal characteristics of Inter Spike Intervals (ISI) is seen to occur as a function of fluctuation parameter. Investigation is further carried out for coupled system of neurons. Cooperative dynamics of coupled neurons are discussed in view of synchronization. Total and partial synchronization regimes are depicted with the help of contour plots of synchrony measure under various conditions. Results of this investigation may provide a basis for exploring the complexities of neural communication and brain functioning.

Clinical Applications of a CT Window Blending Algorithm: RADIO (Relative Attenuation-Dependent Image Overlay).

PubMed

Mandell, Jacob C; Khurana, Bharti; Folio, Les R; Hyun, Hyewon; Smith, Stacy E; Dunne, Ruth M; Andriole, Katherine P

2017-06-01

A methodology is described using Adobe Photoshop and Adobe Extendscript to process DICOM images with a Relative Attenuation-Dependent Image Overlay (RADIO) algorithm to visualize the full dynamic range of CT in one view, without requiring a change in window and level settings. The potential clinical uses for such an algorithm are described in a pictorial overview, including applications in emergency radiology, oncologic imaging, and nuclear medicine and molecular imaging.

Defensive efficacy interim design: Dynamic benefit/risk ratio view using probability of success.

PubMed

Tang, Zhongwen

2017-01-01

Traditional efficacy interim design is based on alpha spending which does not have intuitive interpretation and hence is difficult to communicate with non-statistician colleagues. The alpha-spending approach is based on efficacy alone and hence does not have the flexibility to incorporate newly emerged safety signal. Newly emerged safety signal may nullify the originally set efficacy boundary. In contrast, the probability of success (POS) concept has intuitive interpretation and hence can facilitate our communication with non-statistician colleagues and help to obtain health authority (HA) buying. The success criteria of POS are not restricted to statistical significance. Hence, POS has the capability to incorporate both efficacy and safety information. We propose to use POS and its credible interval to design efficacy interim. In the proposed method, the efficacy boundary is adjustable to offset newly emerged safety signal.

A metaphysics of living systems: the Yōga-Vāsistha view.

PubMed

Narasimha, Roddam

2002-12-01

The Yōga-Vāsistha is a rich and complex philosophical 'poem' (kāvya) of epic length, written in classical Sanskrit by an unknown author some time between the 6th and 13th centuries CE, probably around the 7th century. It is notable for its eloquent praise of self-effort and enquiry or analysis, and for its severe disparagement of the notion of fate. It views consciousness as (a) characterizing all living forms (including plant and insect life), (b) being atomic, and (c) analogous to the emergence of waves and whirlpools in water; it therefore grapples with what today would be called the problems of reductionism and emergentism. Notions of the survival of the fittest, and of a dynamic process of creation and loss, are expressed with characteristic force. The paper presents a selection of verses (in an English translation) setting forth these views, and a brief analysis of their implications.

Molecular mechanisms of cryoprotection in aqueous proline: light scattering and molecular dynamics simulations.

PubMed

Troitzsch, R Z; Vass, H; Hossack, W J; Martyna, G J; Crain, J

2008-04-10

Free proline amino acid is a natural cryoprotectant expressed by numerous organisms under low-temperature stress. Previous reports have suggested that complex assemblies underlie its functional properties. We investigate here aqueous proline solutions as a function of temperature using combinations of Raman spectroscopy, Rayleigh-Brillouin light scattering, and molecular dynamics simulations with the view to revealing the molecular origins of the mixtures' functionality as a cryoprotectant. The evolution of the Brillouin frequency shifts and line widths with temperature shows that, above a critical proline concentration, the water-like dynamics is suppressed and viscoelastic behavior emerges: Here, the Landau-Placzek ratio also shows a temperature-independent maximum arising from concentration fluctuations. Molecular dynamics simulations reveal that the water-water correlations in the mixtures depend much more weakly on temperature than does bulk water. By contrast, the water OH Raman bands exhibit strong red-shifts on cooling similar to those seen in ices; however, no evidence of ice lattice phonons is observed in the low-frequency spectrum. We attribute this primarily to enhanced proline-water hydrogen bonding. In general, the picture that emerges is that aqueous proline is a heterogeneous mixture on molecular length scales (characterized by significant concentration fluctuations rather than well-defined aggregates). Simulations reveal that proline also appears to suppress the normal dependence of water structure on temperature and preserves the ambient-temperature correlations even in very cold solutions. The water structure in cold proline solutions therefore appears to be similar to that at a higher effective temperature. This, coupled with the emergence of glassy dynamics offers a molecular explanation for the functional properties of proline as a cryoprotectant without the need to invoke previously proposed complex aggregates.

Current and emerging business models in the health care information technology industry: a view from wall street.

PubMed

Frank, Seth

2003-01-01

When we think about health care IT, we don't just think about clinical automation with the movement to computerized physician order entry (CPOE), but also the need to upgrade legacy financial and administrative systems to interact with clinical systems. Technology acceptance by physicians remains low, and computer use by physicians for data entry and analysis remains minimal. We expect this trend to change, and expect increased automation to represent gradual change. The HCIT space is dynamic, with many opportunities, but also many challenges. The unique nature of the end market buyers, existing business models, and nature of the technology makes this a challenging but dynamic area for equity investment.

Quench dynamics of the interacting Bose gas in one dimension.

PubMed

Iyer, Deepak; Andrei, Natan

2012-09-14

We obtain an exact expression for the time evolution of the interacting Bose gas following a quench from a generic initial state using the Yudson representation for integrable systems. We study the time evolution of the density and noise correlation for a small number of bosons and their asymptotic behavior for any number. We show that for any value of the coupling, as long as it is repulsive, the system asymptotes towards a strongly repulsive gas, while for any value of an attractive coupling the long time behavior is dominated by the maximal bound state. This occurs independently of the initial state and can be viewed as an emerging "dynamic universality."

Exploring viral infection using single-cell sequencing.

PubMed

Rato, Sylvie; Golumbeanu, Monica; Telenti, Amalio; Ciuffi, Angela

2017-07-15

Single-cell sequencing (SCS) has emerged as a valuable tool to study cellular heterogeneity in diverse fields, including virology. By studying the viral and cellular genome and/or transcriptome, the dynamics of viral infection can be investigated at single cell level. Most studies have explored the impact of cell-to-cell variation on the viral life cycle from the point of view of the virus, by analyzing viral sequences, and from the point of view of the cell, mainly by analyzing the cellular host transcriptome. In this review, we will focus on recent studies that use single-cell sequencing to explore viral diversity and cell variability in response to viral replication. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Non-Separability and Synchronicity: Pauli, Jung and a New Historical, Philosophical Perspective on Quantum Physics

NASA Astrophysics Data System (ADS)

Giannetto, E. A.; Pozzi, F.

We would like to discuss the historical emergence of quantum physics and quantum non-separability, by analysing Pauli's point of view in relation to Jung's ideas. Recent inquiries on EPR shows that quantum non-separability indicates an a-causal connection of the "quantum reality" for space-like intervals ("simultaneity region ") of world (measurement) events: this non-causal connection is the physical counterpart of what Jung called "synchronicity " with an assessment given also by Pauli. This does not imply any violation of mechanical causality by any introduction of action-at-a-distance. From a physical point of view a-causal connections can be interpreted as implying a particular quantum topology of space-time, which leads to a non-mechanistic conception of nature and which could be related to a holistic quantum dynamical reality of the world like Bohm's "holomovement" or "light". This kind of non-mechanistic conception of nature as well as the idea of non-separability of the world and of synchronicity, as stated by Jung itself, was developed by Leibnitz: from this point of view, we can look at quantum physics (as well as for relativity it was shown) as related to a new emergence of concepts belonging to the Leibnitzian (anti-Newtonian) tradition.

From Mild to WildLV14378 Fluctuations in Crystal Plasticity

NASA Astrophysics Data System (ADS)

Weiss, J.; Rhouma, W. Ben; Richeton, T.; Dechanel, S.; Louchet, F.; Truskinovsky, L.

2015-03-01

Macroscopic crystal plasticity is classically viewed as an outcome of uncorrelated dislocation motions producing Gaussian fluctuations. An apparently conflicting picture emerged in recent years emphasizing highly correlated dislocation dynamics characterized by power-law distributed fluctuations. We use acoustic emission measurements in crystals with different symmetries to show that intermittent and continuous visions of plastic flow are not incompatible. We demonstrate the existence of crossover regimes where strongly intermittent events coexist with a Gaussian quasiequilibrium background and propose a simple theoretical framework compatible with these observations.

Speech as a breakthrough signaling resource in the cognitive evolution of biological complex adaptive systems.

PubMed

Mattei, Tobias A

2014-12-01

In self-adapting dynamical systems, a significant improvement in the signaling flow among agents constitutes one of the most powerful triggering events for the emergence of new complex behaviors. Ackermann and colleagues' comprehensive phylogenetic analysis of the brain structures involved in acoustic communication provides further evidence of the essential role which speech, as a breakthrough signaling resource, has played in the evolutionary development of human cognition viewed from the standpoint of complex adaptive system analysis.

Nonlinear dynamics of charged particles in the magnetotail

NASA Technical Reports Server (NTRS)

Chen, James

1992-01-01

An important region of the earth's magnetosphere is the nightside magnetotail, which is believed to play a significant role in energy storage and release associated with substorms. The magnetotail contains a current sheet which separates regions of oppositely directed magnetic field. Particle motion in the collisionless magnetotail has been a long-standing problem. Recent research from the dynamical point of view has yielded considerable new insights into the fundamental properties of orbits and of particle distribution functions. A new framework of understanding magnetospheric plasma properties is emerging. Some novel predictions based directly on nonlinear dynamics have proved to be robust and in apparent good agreement with observation. The earth's magnetotail may serve as a paradigm, one accessible by in situ observation, of a broad class of boundary regions with embedded current sheets. This article reviews the nonlinear dynamics of charged particles in the magnetotail configuration. The emphasis is on the relationships between the dynamics and physical observables. At the end of the introduction, sections containing basic material are indicated.

Power output and carrier dynamics studies of perovskite solar cells under working conditions.

PubMed

Yu, Man; Wang, Hao-Yi; Hao, Ming-Yang; Qin, Yujun; Fu, Li-Min; Zhang, Jian-Ping; Ai, Xi-Cheng

2017-08-02

Perovskite solar cells have emerged as promising photovoltaic systems with superb power conversion efficiency. For the practical application of perovskite devices, the greatest concerns are the power output density and the related dynamics under working conditions. In this study, the working conditions of planar and mesoscopic perovskite solar cells are simulated and the power output density evolutions with the working voltage are highlighted. The planar device exhibits higher capability of outputting power than the mesoscopic one. The transient photoelectric conversion dynamics are investigated under the open circuit, short circuit and working conditions. It is found that the power output and dynamic processes are correlated intrinsically, which suggests that the power output is the competitive result of the charge carrier recombination and transport. The present work offers a unique view to elucidating the relationship between the power output and the charge carrier dynamics for perovskite solar cells in a comprehensive manner, which would be beneficial to their future practical applications.

Attentional synchrony and the influence of viewing task on gaze behavior in static and dynamic scenes.

PubMed

Smith, Tim J; Mital, Parag K

2013-07-17

Does viewing task influence gaze during dynamic scene viewing? Research into the factors influencing gaze allocation during free viewing of dynamic scenes has reported that the gaze of multiple viewers clusters around points of high motion (attentional synchrony), suggesting that gaze may be primarily under exogenous control. However, the influence of viewing task on gaze behavior in static scenes and during real-world interaction has been widely demonstrated. To dissociate exogenous from endogenous factors during dynamic scene viewing we tracked participants' eye movements while they (a) freely watched unedited videos of real-world scenes (free viewing) or (b) quickly identified where the video was filmed (spot-the-location). Static scenes were also presented as controls for scene dynamics. Free viewing of dynamic scenes showed greater attentional synchrony, longer fixations, and more gaze to people and areas of high flicker compared with static scenes. These differences were minimized by the viewing task. In comparison with the free viewing of dynamic scenes, during the spot-the-location task fixation durations were shorter, saccade amplitudes were longer, and gaze exhibited less attentional synchrony and was biased away from areas of flicker and people. These results suggest that the viewing task can have a significant influence on gaze during a dynamic scene but that endogenous control is slow to kick in as initial saccades default toward the screen center, areas of high motion and people before shifting to task-relevant features. This default-like viewing behavior returns after the viewing task is completed, confirming that gaze behavior is more predictable during free viewing of dynamic than static scenes but that this may be due to natural correlation between regions of interest (e.g., people) and motion.

Seasonal variability in the South Asian monsoon dynamics

NASA Astrophysics Data System (ADS)

Bordoni, S.; Walker, J. M.

2017-12-01

Here, we analyze seasonal changes in the dynamics and thermodynamics of the South Asian summer monsoon (SASM) in atmospheric reanalysis data using a threshold-independent index of monsoon onset we have recently introduced (Walker and Bordoni 2016). We seek to evaluate the extent to which emerging theoretical frameworks are consistent with the observed monsoon. Climatological composites reveal that at monsoon onset, an abrupt strengthening and northward migration of the maximum in sub-cloud equivalent potential temperature accompany the rapid northward movement of the monsoon rainbelt. These changes are driven by changes in near-surface specific humidity, rather than changes in near-surface temperature, whose gradient actually decreases at monsoon onset. These findings are inconsistent with the traditional paradigm of the monsoon as a sea breeze circulation and confirm the convectively coupled view of the SASM circulation as an energetically-direct overturning circulation as more fundamental for the understanding of monsoon dynamics. Providing further support to this emerging view, we show that the SASM sector mean circulation at monsoon onset undergoes a rapid transition from an equinox circulation with a pair of tropical overturning cells, to a solstice circulation dominated by a strong cross-equatorial monsoonal cell and negligible overturning cell in the northern hemisphere.This transition corresponds to a transition in the leading order momentum budget, from an eddy-dominated equinox regime to a highly nonlinear monsoon regime which approaches conservation of angular momentum. These transitions are similar to those seen in idealized zonally symmetric studies of aquaplanet monsoons, suggesting that eddy-mean flow feedbacks identified in those studies may be acting in the SASM sector, and may contribute to the abruptness of the SASM onset. Our findings highlight the importance of nonlinear dynamics in the seasonal evolution of the SASM circulation and suggest that some fundamental aspects of the observed monsoon can be understood in the absence of land-sea contrast or other zonal asymmetries.

Cross-cultural comparison of need importance and need satisfaction during adolescence: Turkey and the United States.

PubMed

Hortaçsu, N

1997-09-01

Turkish and U.S. adolescents' views concerning the importance of different needs and instrumentality of relationships with mothers, fathers, siblings, and same-sex friends for need satisfaction were examined and compared. Questionnaires covered needs related to crucial issues of adolescence, namely, relatedness and autonomy/individuation. Participants were 12- to 17-year-old boys and girls from intact families. Cross-cultural differences in ascribed importance of needs related to some aspects of relatedness and autonomy/individuation emerged. Cross-cultural similarities in ascribed importance of needs related to feelings of basic acceptance and need for self-understanding/development also emerged. Turkish adolescents perceived mothers as more instrumental for need satisfaction than did U.S. adolescents. Gender differences in importance ascribed to different needs also emerged. Cross-cultural differences were consistent with differences in predominant values and model family dynamics of the respective countries.

The Emergence of Visual Awareness: Temporal Dynamics in Relation to Task and Mask Type

PubMed Central

Kiefer, Markus; Kammer, Thomas

2017-01-01

One aspect of consciousness phenomena, the temporal emergence of visual awareness, has been subject of a controversial debate. How can visual awareness, that is the experiential quality of visual stimuli, be characterized best? Is there a sharp discontinuous or dichotomous transition between unaware and fully aware states, or does awareness emerge gradually encompassing intermediate states? Previous studies yielded conflicting results and supported both dichotomous and gradual views. It is well conceivable that these conflicting results are more than noise, but reflect the dynamic nature of the temporal emergence of visual awareness. Using a psychophysical approach, the present research tested whether the emergence of visual awareness is context-dependent with a temporal two-alternative forced choice task. During backward masking of word targets, it was assessed whether the relative temporal sequence of stimulus thresholds is modulated by the task (stimulus presence, letter case, lexical decision, and semantic category) and by mask type. Four masks with different similarity to the target features were created. Psychophysical functions were then fitted to the accuracy data in the different task conditions as a function of the stimulus mask SOA in order to determine the inflection point (conscious threshold of each feature) and slope of the psychophysical function (transition from unaware to aware within each feature). Depending on feature-mask similarity, thresholds in the different tasks were highly dispersed suggesting a graded transition from unawareness to awareness or had less differentiated thresholds indicating that clusters of features probed by the tasks quite simultaneously contribute to the percept. The latter observation, although not compatible with the notion of a sharp all-or-none transition between unaware and aware states, suggests a less gradual or more discontinuous emergence of awareness. Analyses of slopes of the fitted psychophysical functions also indicated that the emergence of awareness of single features is variable and might be influenced by the continuity of the feature dimensions. The present work thus suggests that the emergence of awareness is neither purely gradual nor dichotomous, but highly dynamic depending on the task and mask type. PMID:28316583

Towards an evolutionary theory of the origin of life based on kinetics and thermodynamics.

PubMed

Pascal, Robert; Pross, Addy; Sutherland, John D

2013-11-06

A sudden transition in a system from an inanimate state to the living state-defined on the basis of present day living organisms-would constitute a highly unlikely event hardly predictable from physical laws. From this uncontroversial idea, a self-consistent representation of the origin of life process is built up, which is based on the possibility of a series of intermediate stages. This approach requires a particular kind of stability for these stages-dynamic kinetic stability (DKS)-which is not usually observed in regular chemistry, and which is reflected in the persistence of entities capable of self-reproduction. The necessary connection of this kinetic behaviour with far-from-equilibrium thermodynamic conditions is emphasized and this leads to an evolutionary view for the origin of life in which multiplying entities must be associated with the dissipation of free energy. Any kind of entity involved in this process has to pay the energetic cost of irreversibility, but, by doing so, the contingent emergence of new functions is made feasible. The consequences of these views on the studies of processes by which life can emerge are inferred.

Entropy density of spacetime and the Navier-Stokes fluid dynamics of null surfaces

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

Padmanabhan, T.

2011-02-15

It has been known for several decades that Einstein's field equations, when projected onto a null surface, exhibit a structure very similar to the nonrelativistic Navier-Stokes equation. I show that this result arises quite naturally when gravitational dynamics is viewed as an emergent phenomenon. Extremizing the spacetime entropy density associated with the null surfaces leads to a set of equations which, when viewed in the local inertial frame, becomes identical to the Navier-Stokes equation. This is in contrast to the usual description of the Damour-Navier-Stokes equation in a general coordinate system, in which there appears a Lie derivative rather thanmore » a convective derivative. I discuss this difference, its importance, and why it is more appropriate to view the equation in a local inertial frame. The viscous force on fluid, arising from the gradient of the viscous stress-tensor, involves the second derivatives of the metric and does not vanish in the local inertial frame, while the viscous stress-tensor itself vanishes so that inertial observers detect no dissipation. We thus provide an entropy extremization principle that leads to the Damour-Navier-Stokes equation, which makes the hydrodynamical analogy with gravity completely natural and obvious. Several implications of these results are discussed.« less

Dynamically enriched topological orders in driven two-dimensional systems

NASA Astrophysics Data System (ADS)

Potter, Andrew C.; Morimoto, Takahiro

2017-04-01

Time-periodic driving of a quantum system can enable new dynamical topological phases of matter that could not exist in thermal equilibrium. We investigate two related classes of dynamical topological phenomena in 2D systems: Floquet symmetry-protected topological phases (FSPTs) and Floquet enriched topological orders (FETs). By constructing solvable lattice models for a complete set of 2D bosonic FSPT phases, we show that bosonic FSPTs can be understood as topological pumps which deposit loops of 1D SPT chains onto the boundary during each driving cycle, which protects a nontrivial edge state by dynamically tuning the edge to a self-dual point poised between the 1D SPT and trivial phases of the edge. By coupling these FSPT models to dynamical gauge fields, we construct solvable models of FET orders in which anyon excitations are dynamically transmuted into topologically distinct anyon types during each driving period. These bosonic FSPT and gauged FSPT models are classified by group cohomology methods. In addition, we also construct examples of "beyond cohomology" FET orders, which can be viewed as topological pumps of 1D topological chains formed of emergent anyonic quasiparticles.

Epidemics Modelings: Some New Challenges

NASA Astrophysics Data System (ADS)

Boatto, Stefanella; Khouri, Renata Stella; Solerman, Lucas; Codeço, Claudia; Bonnet, Catherine

2010-09-01

Epidemics modeling has been particularly growing in the past years. In epidemics studies, mathematical modeling is used in particular to reach a better understanding of some neglected diseases (dengue, malaria, …) and of new emerging ones (SARS, influenza A,….) of big agglomerates. Such studies offer new challenges both from the modeling point of view (searching for simple models which capture the main characteristics of the disease spreading), data analysis and mathematical complexity. We are facing often with complex networks especially when modeling the city dynamics. Such networks can be static (in first approximation) and homogeneous, static and not homogeneous and/or not static (when taking into account the city structure, micro-climates, people circulation, etc.). The objective being studying epidemics dynamics and being able to predict its spreading.

Endoplasmic Reticulum and the Unfolded Protein Response: Dynamics and Metabolic Integration

PubMed Central

Bravo, Roberto; Parra, Valentina; Gatica, Damián; Rodriguez, Andrea E.; Torrealba, Natalia; Paredes, Felipe; Wang, Zhao V.; Zorzano, Antonio; Hill, Joseph A.; Jaimovich, Enrique; Quest, Andrew F.G.; Lavandero, Sergio

2013-01-01

The endoplasmic reticulum (ER) is a dynamic intracellular organelle with multiple functions essential for cellular homeostasis, development, and stress responsiveness. In response to cellular stress, a well-established signaling cascade, the unfolded protein response (UPR), is activated. This intricate mechanism is an important means of reestablishing cellular homeostasis and alleviating the inciting stress. Now, emerging evidence has demonstrated that the UPR influences cellular metabolism through diverse mechanisms, including calcium and lipid transfer, raising the prospect of involvement of these processes in the pathogenesis of disease, including neurodegeneration, cancer, diabetes mellitus and cardiovascular disease. Here, we review the distinct functions of the ER and UPR from a metabolic point of view, highlighting their association with prevalent pathologies. PMID:23317820

Emerging technology for advancing the treatment of epilepsy using a dynamic control framework.

PubMed

Stanslaski, Scott; Giftakis, John; Stypulkowski, Paul; Carlson, Dave; Afshar, Pedram; Cong, Peng; Denison, Timothy

2011-01-01

We briefly describe a dynamic control system framework for neuromodulation for epilepsy, with an emphasis on its practical challenges and the preliminary validation of key prototype technologies in a chronic animal model. The current state of neuromodulation can be viewed as a classical dynamic control framework such that the nervous system is the classical "plant", the neural stimulator is the controller/actuator, clinical observation, patient diaries and/or measured bio-markers are the sensor, and clinical judgment applied to these sensor inputs forms the state estimator. Technology can potentially address two main factors contributing to the performance limitations of existing systems: "observability," the ability to observe the state of the system from output measurements, and "controllability," the ability to drive the system to a desired state. In addition to improving sensors and actuator performance, methods and tools to better understand disease state dynamics and state estimation are also critical for improving therapy outcomes. We describe our preliminary validation of key "observability" and "controllability" technology blocks using an implanted research tool in an epilepsy disease model. This model allows for testing the key emerging technologies in a representative neural network of therapeutic importance. In the future, we believe these technologies might enable both first principles understanding of neural network behavior for optimizing therapy design, and provide a practical pathway towards clinical translation.

Natural and bio-inspired underwater adhesives: Current progress and new perspectives

NASA Astrophysics Data System (ADS)

Cui, Mengkui; Ren, Susu; Wei, Shicao; Sun, Chengjun; Zhong, Chao

2017-11-01

Many marine organisms harness diverse protein molecules as underwater adhesives to achieve strong and robust interfacial adhesion under dynamic and turbulent environments. Natural underwater adhesion phenomena thus provide inspiration for engineering adhesive materials that can perform in water or high-moisture settings for biomedical and industrial applications. Here we review examples of biological adhesives to show the molecular features of natural adhesives and discuss how such knowledge serves as a heuristic guideline for the rational design of biologically inspired underwater adhesives. In view of future bio-inspired research, we propose several potential opportunities, either in improving upon current L-3, 4-dihydroxyphenylalanine-based and coacervates-enabled adhesives with new features or engineering conceptually new types of adhesives that recapitulate important characteristics of biological adhesives. We underline the importance of viewing natural adhesives as dynamic materials, which owe their outstanding performance to the cellular coordination of protein expression, delivery, deposition, assembly, and curing of corresponding components with spatiotemporal control. We envision that the emerging synthetic biology techniques will provide great opportunities for advancing both fundamental and application aspects of underwater adhesives.

Epigenetic legacy of parental experiences: Dynamic and interactive pathways to inheritance.

PubMed

Champagne, Frances A

2016-11-01

The quality of the environment experienced by an individual across his or her lifespan can result in a unique developmental trajectory with consequences for adult phenotype and reproductive success. However, it is also evident that these experiences can impact the development of offspring with continued effect on subsequent generations. Epigenetic mechanisms have been proposed as a mediator of both these within- and across-generation effects, and there is increasing evidence to support the role of environmentally induced changes in DNA methylation, posttranslational histone modifications, and noncoding RNAs in predicting these outcomes. Advances in our understanding of these molecular modifications contribute to increasingly nuanced perspectives on plasticity and transmission of phenotypes across generations. A challenge that emerges from this research is in how we integrate these "new" perspectives with traditional views of development, reproduction, and inheritance. This paper will highlight evidence suggestive of an epigenetic impact of the environment on mothers, fathers, and their offspring, and illustrate the importance of considering the dynamic nature of reproduction and development and inclusive views of inheritance within the evolving field of behavioral and environmental epigenetics.

How does public opinion become extreme?

NASA Astrophysics Data System (ADS)

Ramos, Marlon; Shao, Jia; Reis, Saulo D. S.; Anteneodo, Celia; Andrade, José S.; Havlin, Shlomo; Makse, Hernán A.

2015-05-01

We investigate the emergence of extreme opinion trends in society by employing statistical physics modeling and analysis on polls that inquire about a wide range of issues such as religion, economics, politics, abortion, extramarital sex, books, movies, and electoral vote. The surveys lay out a clear indicator of the rise of extreme views. The precursor is a nonlinear relation between the fraction of individuals holding a certain extreme view and the fraction of individuals that includes also moderates, e.g., in politics, those who are “very conservative” versus “moderate to very conservative” ones. We propose an activation model of opinion dynamics with interaction rules based on the existence of individual “stubbornness” that mimics empirical observations. According to our modeling, the onset of nonlinearity can be associated to an abrupt bootstrap-percolation transition with cascades of extreme views through society. Therefore, it represents an early-warning signal to forecast the transition from moderate to extreme views. Moreover, by means of a phase diagram we can classify societies according to the percolative regime they belong to, in terms of critical fractions of extremists and people’s ties.

How does public opinion become extreme?

PubMed Central

Ramos, Marlon; Shao, Jia; Reis, Saulo D. S.; Anteneodo, Celia; Andrade, José S.; Havlin, Shlomo; Makse, Hernán A.

2015-01-01

We investigate the emergence of extreme opinion trends in society by employing statistical physics modeling and analysis on polls that inquire about a wide range of issues such as religion, economics, politics, abortion, extramarital sex, books, movies, and electoral vote. The surveys lay out a clear indicator of the rise of extreme views. The precursor is a nonlinear relation between the fraction of individuals holding a certain extreme view and the fraction of individuals that includes also moderates, e.g., in politics, those who are “very conservative” versus “moderate to very conservative” ones. We propose an activation model of opinion dynamics with interaction rules based on the existence of individual “stubbornness” that mimics empirical observations. According to our modeling, the onset of nonlinearity can be associated to an abrupt bootstrap-percolation transition with cascades of extreme views through society. Therefore, it represents an early-warning signal to forecast the transition from moderate to extreme views. Moreover, by means of a phase diagram we can classify societies according to the percolative regime they belong to, in terms of critical fractions of extremists and people’s ties. PMID:25989484

How does public opinion become extreme?

PubMed

Ramos, Marlon; Shao, Jia; Reis, Saulo D S; Anteneodo, Celia; Andrade, José S; Havlin, Shlomo; Makse, Hernán A

2015-05-19

We investigate the emergence of extreme opinion trends in society by employing statistical physics modeling and analysis on polls that inquire about a wide range of issues such as religion, economics, politics, abortion, extramarital sex, books, movies, and electoral vote. The surveys lay out a clear indicator of the rise of extreme views. The precursor is a nonlinear relation between the fraction of individuals holding a certain extreme view and the fraction of individuals that includes also moderates, e.g., in politics, those who are "very conservative" versus "moderate to very conservative" ones. We propose an activation model of opinion dynamics with interaction rules based on the existence of individual "stubbornness" that mimics empirical observations. According to our modeling, the onset of nonlinearity can be associated to an abrupt bootstrap-percolation transition with cascades of extreme views through society. Therefore, it represents an early-warning signal to forecast the transition from moderate to extreme views. Moreover, by means of a phase diagram we can classify societies according to the percolative regime they belong to, in terms of critical fractions of extremists and people's ties.

Patterns of gender development.

PubMed

Martin, Carol Lynn; Ruble, Diane N

2010-01-01

A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains-sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development.

Patterns of Gender Development

PubMed Central

Martin, Carol Lynn; Ruble, Diane N.

2013-01-01

A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains—sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development. PMID:19575615

The evolutionary dynamics of language.

PubMed

Steels, Luc; Szathmáry, Eörs

2018-02-01

The well-established framework of evolutionary dynamics can be applied to the fascinating open problems how human brains are able to acquire and adapt language and how languages change in a population. Schemas for handling grammatical constructions are the replicating unit. They emerge and multiply with variation in the brains of individuals and undergo selection based on their contribution to needed expressive power, communicative success and the reduction of cognitive effort. Adopting this perspective has two major benefits. (i) It makes a bridge to neurobiological models of the brain that have also adopted an evolutionary dynamics point of view, thus opening a new horizon for studying how human brains achieve the remarkably complex competence for language. And (ii) it suggests a new foundation for studying cultural language change as an evolutionary dynamics process. The paper sketches this novel perspective, provides references to empirical data and computational experiments, and points to open problems. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Dynamical Analysis and Visualization of Tornadoes Time Series

PubMed Central

2015-01-01

In this paper we analyze the behavior of tornado time-series in the U.S. from the perspective of dynamical systems. A tornado is a violently rotating column of air extending from a cumulonimbus cloud down to the ground. Such phenomena reveal features that are well described by power law functions and unveil characteristics found in systems with long range memory effects. Tornado time series are viewed as the output of a complex system and are interpreted as a manifestation of its dynamics. Tornadoes are modeled as sequences of Dirac impulses with amplitude proportional to the events size. First, a collection of time series involving 64 years is analyzed in the frequency domain by means of the Fourier transform. The amplitude spectra are approximated by power law functions and their parameters are read as an underlying signature of the system dynamics. Second, it is adopted the concept of circular time and the collective behavior of tornadoes analyzed. Clustering techniques are then adopted to identify and visualize the emerging patterns. PMID:25790281

Dynamical analysis and visualization of tornadoes time series.

PubMed

Lopes, António M; Tenreiro Machado, J A

2015-01-01

In this paper we analyze the behavior of tornado time-series in the U.S. from the perspective of dynamical systems. A tornado is a violently rotating column of air extending from a cumulonimbus cloud down to the ground. Such phenomena reveal features that are well described by power law functions and unveil characteristics found in systems with long range memory effects. Tornado time series are viewed as the output of a complex system and are interpreted as a manifestation of its dynamics. Tornadoes are modeled as sequences of Dirac impulses with amplitude proportional to the events size. First, a collection of time series involving 64 years is analyzed in the frequency domain by means of the Fourier transform. The amplitude spectra are approximated by power law functions and their parameters are read as an underlying signature of the system dynamics. Second, it is adopted the concept of circular time and the collective behavior of tornadoes analyzed. Clustering techniques are then adopted to identify and visualize the emerging patterns.

Landscape Pattern Determines Neighborhood Size and Structure within a Lizard Population

PubMed Central

Ryberg, Wade A.; Hill, Michael T.; Painter, Charles W.; Fitzgerald, Lee A.

2013-01-01

Although defining population structure according to discrete habitat patches is convenient for metapopulation theories, taking this approach may overlook structure within populations continuously distributed across landscapes. For example, landscape features within habitat patches direct the movement of organisms and define the density distribution of individuals, which can generate spatial structure and localized dynamics within populations as well as among them. Here, we use the neighborhood concept, which describes population structure relative to the scale of individual movements, to illustrate how localized dynamics within a population of lizards (Sceloporus arenicolus) arise in response to variation in landscape pattern within a continuous habitat patch. Our results emphasize links between individual movements at small scales and the emergence of spatial structure within populations which resembles metapopulation dynamics at larger scales. We conclude that population dynamics viewed in a landscape context must consider the explicit distribution and movement of individuals within continuous habitat as well as among habitat patches. PMID:23441217

Active Polar Gels: a Paradigm for Cytoskeletal Dynamics

NASA Astrophysics Data System (ADS)

Julicher, Frank

2006-03-01

The cytoskeleton of eucaryotic cells is an intrinsically dynamic network of rod-like filaments. Active processes on the molecular scale such as the action of motor proteins and the polymerization and depolymerization of filaments drive active dynamic behaviors while consuming chemical energy in the form of a fuel. Such emergent dynamics is regulated by the cell and is important for many cellular processes such as cell locomotion and cell division. From a general point of view the cytoskeleton represents an active gel-like material with interesting material properties. We present a general theory of active viscoelastic materials made of polar filaments which is motivated by the the cytoskeleton. The continuous consumption of a fuel generates a non- equilibrium state characterized by the generation of flows and stresses. Our theory can be applied to experiments in which cytoskeletal patterns are set in motion by active processes such as those which are at work in cells. It can also capture generic aspects of the flows and stress profiles which occur during cell locomotion.

Jung's dissociable psyche and the ec-static self.

PubMed

Austin, Sue

2009-11-01

Much of Jung's later work assumes that the self is an a priori phenomenon in which centripetal dynamics dominate. There is, however, another current in Jung's writings which recognizes the self to be an emergent phenomenon. This view is increasingly prevalent in post-Jungian discourse, and Louis Zinkin's exploration of a post-Jungian-constructivist model of the self can be seen as part of this tendency. My paper privileges an emergent understanding of the self by focusing on the 'unravelling', 'de-centring', centrifugal experiences of otherness in the psyche. It offers a post-Jungian reading of a number of writers who have been influenced by the psychoanalyst Jean Laplanche and proposes a model of the self which focuses on our fantasies, terrors and longings about coming undone and bringing others undone. This model is then linked to Judith Butler's understanding of the self as an ec-static phenomenon, in which the self is, of necessity, outside itself, such that 'there is no final moment in which my return to myself takes place'. I suggest that Jung's early clinical researches into the dissociability of the psyche and the clinical tools which he developed as a result of this work are especially suitable for engaging with these emergent, centrifugal dynamics.

Frequency-band signatures of visual responses to naturalistic input in ferret primary visual cortex during free viewing.

PubMed

Sellers, Kristin K; Bennett, Davis V; Fröhlich, Flavio

2015-02-19

Neuronal firing responses in visual cortex reflect the statistics of visual input and emerge from the interaction with endogenous network dynamics. Artificial visual stimuli presented to animals in which the network dynamics were constrained by anesthetic agents or trained behavioral tasks have provided fundamental understanding of how individual neurons in primary visual cortex respond to input. In contrast, very little is known about the mesoscale network dynamics and their relationship to microscopic spiking activity in the awake animal during free viewing of naturalistic visual input. To address this gap in knowledge, we recorded local field potential (LFP) and multiunit activity (MUA) simultaneously in all layers of primary visual cortex (V1) of awake, freely viewing ferrets presented with naturalistic visual input (nature movie clips). We found that naturalistic visual stimuli modulated the entire oscillation spectrum; low frequency oscillations were mostly suppressed whereas higher frequency oscillations were enhanced. In average across all cortical layers, stimulus-induced change in delta and alpha power negatively correlated with the MUA responses, whereas sensory-evoked increases in gamma power positively correlated with MUA responses. The time-course of the band-limited power in these frequency bands provided evidence for a model in which naturalistic visual input switched V1 between two distinct, endogenously present activity states defined by the power of low (delta, alpha) and high (gamma) frequency oscillatory activity. Therefore, the two mesoscale activity states delineated in this study may define the degree of engagement of the circuit with the processing of sensory input. Copyright © 2014 Elsevier B.V. All rights reserved.

Darwinism, not mutationism, explains the design of organisms.

PubMed

Gardner, Andy

2013-04-01

Shapiro claims that advances in molecular genetics have undermined Darwinism, leading him to advocate mutationism. However, this extreme view is bourne out of conceptual error. He has misunderstood the distinction between gradualism and saltationism, which do not concern the rate of genetic change, but rather the emergence of complex design. And he has misunderstood the relationship between the dynamics of natural selection and the agency of individual organisms: these are not competing hypotheses, but rather alternative conceptualizations of the same phenomenon. Copyright © 2012 Elsevier Ltd. All rights reserved.

The automated system for prevention of industrial-caused diseases

NASA Astrophysics Data System (ADS)

Varnavsky, A. N.

2017-01-01

The paper presents the automated system intended to prevent industrial-caused diseases of workers, the basis of which is represented by algorithms of preventing several negative functional conditions (stress, monotony). The emergence of such state shall be determined based on an analysis of bioelectric signals, in particular, skin-galvanic reactions. Proceeding from the dynamics of the functional state, the automated system offers to perform an optimized set of measures to restore the health of the worker. Implementation of an automated system is presented in Visual Programming system LabVIEW.

Beyond the spatial paradigm: time and cinematic form in holographic art

NASA Astrophysics Data System (ADS)

Kac, Eduardo

1998-02-01

The author discusses holographic art from the point of view of the temporal properties of the medium, using examples from some of the artists who have consistently worked with film, video, digital imaging and holographic animation proper. He suggests that any consideration of this new art form must take into account its dynamic, and not only spatial, qualities. The paper is also complemented with a survey of recent and current research towards holographic film and video, evoking the unique creative potential of these emergent technologies.

Widowhood in old age: Viewed in a family context☆

PubMed Central

Moss, Miriam S.; Moss, Sidney Z.

2014-01-01

Researchers and clinicians have traditionally explored widowhood as an intrapersonal process. We expand the paradigm of bereavement research to explore the widow's perceptions of her experience within a family context. In a study of family bereavement, 24 widows each participated in 2 separate qualitative interviews, followed by standard qualitative analyses of the transcribed narratives. Three inter-related central topics emerged. (1) Widows stress the importance of their independence vis a vis their family as central to their sense of identity. (2) Widows perceive that they and their adult children avoid expressing their feelings of sadness and loss with each other. (3) Widows believe that their children are unable to understand the meaning of the widows' loss because of differences in generations and life situations. Two inter-woven underlying themes emerged: protection of self and of other, and boundaries between widow and children. Just as protection is rooted in a dynamic of separation between widow and child, boundaries are rooted in their deep bond. When researchers and clinicians recognize the dynamics of these two themes they can potentially increase understanding of widowhood within the context of the family. PMID:24655677

Mixed strategy and coevolution dynamics in social networks

NASA Astrophysics Data System (ADS)

Zhong, Weicai; Abbass, Hussein A.; Bender, Axel; Liu, Jing

2011-01-01

We investigate coevolution dynamics of both individual strategies and social ties as they adapt within the snowdrift game with mixed strategies. We propose a partner selection mechanism based on the concept of trust. Here trust is considered an instrument for an individual both selecting the right partners and being selected amongst other potential partners. Based on her local views of the system, the focal individual dismisses the link from the partner with the lowest trust and rewires to the partner’s partner with the highest trust. It is shown that such a trust-based partner switching mechanism favors the emergence of cooperators. Furthermore, when the number of an individual’s partners is restricted (which is a metaphor of limited capacities and capabilities of an individual in real environments), surprising assortative mixing patterns are formed in the emerging network and change the network’s degree distribution from a power-law distribution to an asymmetrically U-shaped distribution. This plays a leading role in preventing global avalanches triggered by perturbations acting on the state of the highly connected individuals.

Hazard perception in emergency medical service responders.

PubMed

Johnston, K A; Scialfa, C T

2016-10-01

The perception of on-road hazards is critically important to emergency medical services (EMS) professionals, the patients they transport and the general public. This study compared hazard perception in EMS and civilian drivers of similar age and personal driving experience. Twenty-nine EMS professionals and 24 non-professional drivers were given a dynamic hazard perception test (HPT). The EMS group demonstrated an advantage in HPT that was independent of simple reaction time, another indication of the validity of the test. These results are also consistent with the view that professional driving experience results in changes in the ability to identify and respond to on-road hazards. Directions for future research include the development of a profession-specific hazard perception tool for both assessment and training purposes. Copyright © 2016 Elsevier Ltd. All rights reserved.

[The dual process model of addiction. Towards an integrated model?].

PubMed

Vandermeeren, R; Hebbrecht, M

2012-01-01

Neurobiology and cognitive psychology have provided us with a dual process model of addiction. According to this model, behavior is considered to be the dynamic result of a combination of automatic and controlling processes. In cases of addiction the balance between these two processes is severely disturbed. Automated processes will continue to produce impulses that ensure the continuance of addictive behavior. Weak, reflective or controlling processes are both the reason for and the result of the inability to forgo addiction. To identify features that are common to current neurocognitive insights into addiction and psychodynamic views on addiction. The picture that emerges from research is not clear. There is some evidence that attentional bias has a causal effect on addiction. There is no evidence that automatic associations have a causal effect, but there is some evidence that automatic action-tendencies do have a causal effect. Current neurocognitive views on the dual process model of addiction can be integrated with an evidence-based approach to addiction and with psychodynamic views on addiction.

Dynamic chest radiography: flat-panel detector (FPD) based functional X-ray imaging.

PubMed

Tanaka, Rie

2016-07-01

Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function. The basic concept was proposed in the 1980s; however, it was not realized until the 2010s because of technical limitations. Dynamic FPDs and advanced digital image processing played a key role for clinical application of dynamic chest radiography. Pulmonary ventilation and circulation can be quantified and visualized for the diagnosis of pulmonary diseases. Dynamic chest radiography can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. Here, we focus on the evaluation of pulmonary ventilation and circulation. This review article describes the basic mechanism of imaging findings according to pulmonary/circulation physiology, followed by imaging procedures, analysis method, and diagnostic performance of dynamic chest radiography.

Being BOLD: The neural dynamics of face perception.

PubMed

Gentile, Francesco; Ales, Justin; Rossion, Bruno

2017-01-01

According to a non-hierarchical view of human cortical face processing, selective responses to faces may emerge in a higher-order area of the hierarchy, in the lateral part of the middle fusiform gyrus (fusiform face area [FFA]) independently from face-selective responses in the lateral inferior occipital gyrus (occipital face area [OFA]), a lower order area. Here we provide a stringent test of this hypothesis by gradually revealing segmented face stimuli throughout strict linear descrambling of phase information [Ales et al., 2012]. Using a short sampling rate (500 ms) of fMRI acquisition and single subject statistical analysis, we show a face-selective responses emerging earlier, that is, at a lower level of structural (i.e., phase) information, in the FFA compared with the OFA. In both regions, a face detection response emerging at a lower level of structural information for upright than inverted faces, both in the FFA and OFA, in line with behavioral responses and with previous findings of delayed responses to inverted faces with direct recordings of neural activity were also reported. Overall, these results support the non-hierarchical view of human cortical face processing and open new perspectives for time-resolved analysis at the single subject level of fMRI data obtained during continuously evolving visual stimulation. Hum Brain Mapp 38:120-139, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

User's Guide for MetView: A Meteorological Display and Assessment Tool

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

Glantz, Clifford S.; Pelton, Mitchell A.; Allwine, K Jerry

2000-09-27

MetView Version 2.0 is an easy-to-use model for accessing, viewing, and analyzing meteorological data. MetView provides both graphical and numerical displays of data. It can accommodate data from an extensive meteorological monitoring network that includes near-surface monitoring locations, instrumented towers, sodars, and meteorologist observations. MetView is used operationally for both routine, emergency response, and research applications at the U.S. Department of Energy's Hanford Site. At the Site's Emergency Operations Center, MetView aids in the access, visualization, and interpretation of real-time meteorological data. Historical data can also be accessed and displayed. Emergency response personnel at the Emergency Operations Center use MetViewmore » products in the formulation of protective action recommendations and other decisions. In the initial stage of an emergency, MetView can be operated using a very simple, five-step procedure. This first-responder procedure allows non-technical staff to rapidly generate meteorological products and disseminate key information. After first-responder information products are produced, the Emergency Operations Center's technical staff can conduct more sophisticated analyses using the model. This may include examining the vertical variation in winds, assessing recent changes in atmospheric conditions, evaluating atmospheric mixing rates, and forecasting changes in meteorological conditions. This user's guide provides easy-to-follow instructions for both first-responder and routine operation of the model. Examples, with explanations, are provided for each type of MetView output display. Information is provided on the naming convention, format, and contents of each type of meteorological data file used by the model area. This user's guide serves as a ready reference for experienced MetView users and a training manual for new users.« less

The Emergence of Life as a First-Order Phase Transition

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

Mathis, Cole; Bhattacharya, Tanmoy; Walker, Sara Imari

It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here in this paper we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase ismore » distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly.« less

The Emergence of Life as a First-Order Phase Transition

DOE PAGES

Mathis, Cole; Bhattacharya, Tanmoy; Walker, Sara Imari

2017-03-01

It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here in this paper we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase ismore » distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly.« less

The Emergence of Life as a First-Order Phase Transition

NASA Astrophysics Data System (ADS)

Mathis, Cole; Bhattacharya, Tanmoy; Imari Walker, Sara

2017-03-01

It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase is distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly.

Christfried Jakob's late views (1930-1949) on the psychogenetic function of the cerebral cortex and its localization: culmination of the neurophilosophical thought of a keen brain observer.

PubMed

Théodoridou, Zoë D; Triarhou, Lazaros C

2012-04-01

This article follows the culmination of the scientific thought of the neurobiologist Christfried Jakob (1866-1956) during the later part of his career, based on publications from 1930 to 1949, when he was between 64 and 83 years of age. Jakob emphasized the necessity of bridging philosophy to the biological sciences, neurobiology in particular. Thus, we consider him as one of the early protagonists in the emergence of neurophilosophy in the 20th century. The topics that occupied his mind were the foundations for a future philosophy of the brain, and the 'neurobiogenetic', 'neurodynamic', and 'neuropsychogenetic' problems in relation to how consciousness emerges. Jakob's views have many elements in common with great thinkers of philosophy and psychology, including Immanuel Kant, William James, Edmund Husserl, Henri Bergson, Jean Piaget and Willard Quine. A common denominator can also be discerned between Jakob's dynamic approach and certain aspects of cybernetics and neurophenomenology. Jakob propounded the interdisciplinarity of sciences as an indispensable tool for ultimately solving the enigma of consciousness. Copyright © 2011 Elsevier Inc. All rights reserved.

Hybrid-view programming of nuclear fusion simulation code in the PGAS parallel programming language XcalableMP

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

Tsugane, Keisuke; Boku, Taisuke; Murai, Hitoshi

Recently, the Partitioned Global Address Space (PGAS) parallel programming model has emerged as a usable distributed memory programming model. XcalableMP (XMP) is a PGAS parallel programming language that extends base languages such as C and Fortran with directives in OpenMP-like style. XMP supports a global-view model that allows programmers to define global data and to map them to a set of processors, which execute the distributed global data as a single thread. In XMP, the concept of a coarray is also employed for local-view programming. In this study, we port Gyrokinetic Toroidal Code - Princeton (GTC-P), which is a three-dimensionalmore » gyrokinetic PIC code developed at Princeton University to study the microturbulence phenomenon in magnetically confined fusion plasmas, to XMP as an example of hybrid memory model coding with the global-view and local-view programming models. In local-view programming, the coarray notation is simple and intuitive compared with Message Passing Interface (MPI) programming while the performance is comparable to that of the MPI version. Thus, because the global-view programming model is suitable for expressing the data parallelism for a field of grid space data, we implement a hybrid-view version using a global-view programming model to compute the field and a local-view programming model to compute the movement of particles. Finally, the performance is degraded by 20% compared with the original MPI version, but the hybrid-view version facilitates more natural data expression for static grid space data (in the global-view model) and dynamic particle data (in the local-view model), and it also increases the readability of the code for higher productivity.« less

Hybrid-view programming of nuclear fusion simulation code in the PGAS parallel programming language XcalableMP

DOE PAGES

Tsugane, Keisuke; Boku, Taisuke; Murai, Hitoshi; ...

2016-06-01

Recently, the Partitioned Global Address Space (PGAS) parallel programming model has emerged as a usable distributed memory programming model. XcalableMP (XMP) is a PGAS parallel programming language that extends base languages such as C and Fortran with directives in OpenMP-like style. XMP supports a global-view model that allows programmers to define global data and to map them to a set of processors, which execute the distributed global data as a single thread. In XMP, the concept of a coarray is also employed for local-view programming. In this study, we port Gyrokinetic Toroidal Code - Princeton (GTC-P), which is a three-dimensionalmore » gyrokinetic PIC code developed at Princeton University to study the microturbulence phenomenon in magnetically confined fusion plasmas, to XMP as an example of hybrid memory model coding with the global-view and local-view programming models. In local-view programming, the coarray notation is simple and intuitive compared with Message Passing Interface (MPI) programming while the performance is comparable to that of the MPI version. Thus, because the global-view programming model is suitable for expressing the data parallelism for a field of grid space data, we implement a hybrid-view version using a global-view programming model to compute the field and a local-view programming model to compute the movement of particles. Finally, the performance is degraded by 20% compared with the original MPI version, but the hybrid-view version facilitates more natural data expression for static grid space data (in the global-view model) and dynamic particle data (in the local-view model), and it also increases the readability of the code for higher productivity.« less

Dynamics of scene representations in the human brain revealed by magnetoencephalography and deep neural networks

PubMed Central

Cichy, Radoslaw Martin; Khosla, Aditya; Pantazis, Dimitrios; Oliva, Aude

2017-01-01

Human scene recognition is a rapid multistep process evolving over time from single scene image to spatial layout processing. We used multivariate pattern analyses on magnetoencephalography (MEG) data to unravel the time course of this cortical process. Following an early signal for lower-level visual analysis of single scenes at ~100 ms, we found a marker of real-world scene size, i.e. spatial layout processing, at ~250 ms indexing neural representations robust to changes in unrelated scene properties and viewing conditions. For a quantitative model of how scene size representations may arise in the brain, we compared MEG data to a deep neural network model trained on scene classification. Representations of scene size emerged intrinsically in the model, and resolved emerging neural scene size representation. Together our data provide a first description of an electrophysiological signal for layout processing in humans, and suggest that deep neural networks are a promising framework to investigate how spatial layout representations emerge in the human brain. PMID:27039703

14 CFR 23.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Emergency Landing Conditions § 23.562 Emergency landing dynamic conditions. (a) Each seat/restraint system... dynamic tests conducted in accordance with paragraph (b) of this section: (1) The seat/restraint system... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 23...

Preschool Staff's View of Emergent Literacy Approaches in Swedish Preschools

ERIC Educational Resources Information Center

Norling, Martina

2014-01-01

This study aims to investigate preschool staff's view of emergent literacy approaches in Swedish preschools with the following research question: How do preschool staff describe and explain the approaches they use in the emergent literacy environment of preschool? Focus-group interviews were conducted with 52 participating preschool units.…

Optimized maritime emergency resource allocation under dynamic demand.

PubMed

Zhang, Wenfen; Yan, Xinping; Yang, Jiaqi

2017-01-01

Emergency resource is important for people evacuation and property rescue when accident occurs. The relief efforts could be promoted by a reasonable emergency resource allocation schedule in advance. As the marine environment is complicated and changeful, the place, type, severity of maritime accident is uncertain and stochastic, bringing about dynamic demand of emergency resource. Considering dynamic demand, how to make a reasonable emergency resource allocation schedule is challenging. The key problem is to determine the optimal stock of emergency resource for supplier centers to improve relief efforts. This paper studies the dynamic demand, and which is defined as a set. Then a maritime emergency resource allocation model with uncertain data is presented. Afterwards, a robust approach is developed and used to make sure that the resource allocation schedule performs well with dynamic demand. Finally, a case study shows that the proposed methodology is feasible in maritime emergency resource allocation. The findings could help emergency manager to schedule the emergency resource allocation more flexibly in terms of dynamic demand.

Optimized maritime emergency resource allocation under dynamic demand

PubMed Central

Yan, Xinping; Yang, Jiaqi

2017-01-01

Emergency resource is important for people evacuation and property rescue when accident occurs. The relief efforts could be promoted by a reasonable emergency resource allocation schedule in advance. As the marine environment is complicated and changeful, the place, type, severity of maritime accident is uncertain and stochastic, bringing about dynamic demand of emergency resource. Considering dynamic demand, how to make a reasonable emergency resource allocation schedule is challenging. The key problem is to determine the optimal stock of emergency resource for supplier centers to improve relief efforts. This paper studies the dynamic demand, and which is defined as a set. Then a maritime emergency resource allocation model with uncertain data is presented. Afterwards, a robust approach is developed and used to make sure that the resource allocation schedule performs well with dynamic demand. Finally, a case study shows that the proposed methodology is feasible in maritime emergency resource allocation. The findings could help emergency manager to schedule the emergency resource allocation more flexibly in terms of dynamic demand. PMID:29240792

Assessment of Diagnostic Value of Single View Dynamic Technique in Diagnosis of Developmental Dysplasia of Hip: A Comparison with Static and Dynamic Ultrasond Techniques

PubMed Central

Alamdaran, Seyed Ali; Kazemi, Sahar; Parsa, Ali; Moghadam, Mohammad Hallaj; Feyzi, Ali; Mardani, Reza

2016-01-01

Background: Developmental dysplasia of hip (DDH) is a common childhood disorder, and ultrasonography examination is routinely used for screening purposes. In this study, we aimed to evaluate a modified combined static and dynamic ultrasound technique for the detection of DDH and to compare with the results of static and dynamic ultrasound techniques. Methods: In this cross-sectional study, during 2013- 2015, 300 high-risk infants were evaluated by ultrasound for DDH. Both hips were examined with three techniques: static, dynamic and single view static and dynamic technique. Statistical analysis was performed using SPSS version 11.5. Results: Patients aged 9 days to 83 weeks. 75% of the patients were 1 to 3 months old. Among 600 hip joints, about 5% were immature in static sonography and almost all of them were unstable in dynamic techniques. 0.3% of morphologically normal hips were unstable in dynamic sonography and 9% of unstable hips had normal morphology. The mean β angle differences in coronal view before and after stress maneuver was 14.43±5.47° in unstable hips. Single view static and dynamic technique revealed that all cases with acetabular dysplasia, instability and dislocation, except two dislocations, were detected by dynamic transverse view. For two cases, Ortolani maneuver showed femoral head reversibility in dislocated hips. Using single view static and dynamic technique was indicative and applicable for detection of more than 99% of cases. Conclusion: Single view static and dynamic technique not only is a fast and easy technique, but also it is of high diagnostic value in assessment of DDH. PMID:27847852

Terahertz absorption of lysozyme in solution

NASA Astrophysics Data System (ADS)

Martin, Daniel R.; Matyushov, Dmitry V.

2017-08-01

Absorption of radiation by solution is described by its frequency-dependent dielectric function and can be viewed as a specific application of the dielectric theory of solutions. For ideal solutions, the dielectric boundary-value problem separates the polar response into the polarization of the void in the liquid, created by the solute, and the response of the solute dipole. In the case of a protein as a solute, protein nuclear dynamics do not project on significant fluctuations of the dipole moment in the terahertz domain of frequencies and the protein dipole can be viewed as dynamically frozen. Absorption of radiation then reflects the interfacial polarization. Here we apply an analytical theory and computer simulations to absorption of radiation by an ideal solution of lysozyme. Comparison with the experiment shows that Maxwell electrostatics fails to describe the polarization of the protein-water interface and the "Lorentz void," which does not anticipate polarization of the interface by the external field (no surface charges), better represents the data. An analytical theory for the slope of the solution absorption against the volume fraction of the solute is formulated in terms of the cavity field response function. It is calculated from molecular dynamics simulations in good agreement with the experiment. The protein hydration shell emerges as a separate sub-ensemble, which, collectively, is not described by the standard electrostatics of dielectrics.

SDO Transit, September 2015

NASA Image and Video Library

2015-09-13

On Sept. 13, 2015, as NASA's Solar Dynamics Observatory, or SDO, kept up its constant watch on the sun, its view was photobombed not once, but twice. Just as the moon came into SDO's field of view on a path to cross the sun, Earth entered the picture, blocking SDO's view completely. When SDO's orbit finally emerged from behind Earth, the moon was just completing its journey across the sun's face. Though SDO sees dozens of Earth eclipses and several lunar transits each year, this is the first time ever that the two have coincided. SDO's orbit usually gives us unobstructed views of the sun, but Earth's revolution around the sun means that SDO's orbit passes behind Earth twice each year, for two to three weeks at a time. During these phases, Earth blocks SDO's view of the sun for anywhere from a few minutes to over an hour once each day. Earth's outline looks fuzzy, while the moon's is crystal-clear. This is because-while the planet itself completely blocks the sun's light-Earth's atmosphere is an incomplete barrier, blocking different amounts of light at different altitudes. However, the moon has no atmosphere, so during the transit we can see the crisp edges of the moon's horizon. http://photojournal.jpl.nasa.gov/catalog/PIA19949

NASA's SDO Catches a Double Photobomb

NASA Image and Video Library

2017-12-08

On Sept. 13, 2015, as NASA’s Solar Dynamics Observatory, or SDO, kept up its constant watch on the sun, its view was photobombed not once, but twice. Just as the moon came into SDO’s field of view on a path to cross the sun, Earth entered the picture, blocking SDO’s view completely. When SDO's view of the sun emerged from Earth’s shadow, the moon was just completing its journey across the sun’s face. Though SDO sees dozens of Earth eclipses and several lunar transits each year, this is the first time ever that the two have coincided. This alignment of the sun, moon and Earth also resulted in a partial solar eclipse on Sept. 13, visible only from parts of Africa and Antarctica. Read more: www.nasa.gov/feature/goddard/nasas-sdo-catches-a-double-p... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

New understanding of rhizosphere processes enabled by advances in molecular and spatially resolved techniques

DOE PAGES

Hess, Nancy J.; Pasa-Tolic, Ljiljana; Bailey, Vanessa L.; ...

2017-04-12

Understanding the role played by microorganisms within soil systems is challenged by the unique intersection of physics, chemistry, mineralogy and biology in fostering habitat for soil microbial communities. To address these challenges will require observations across multiple spatial and temporal scales to capture the dynamics and emergent behavior from complex and interdependent processes. The heterogeneity and complexity of the rhizosphere require advanced techniques that press the simultaneous frontiers of spatial resolution, analyte sensitivity and specificity, reproducibility, large dynamic range, and high throughput. Fortunately many exciting technical advancements are now available to inform and guide the development of new hypotheses. Themore » aim of this Special issue is to provide a holistic view of the rhizosphere in the perspective of modern molecular biology methodologies that enabled a highly-focused, detailed view on the processes in the rhizosphere, including numerous, strong and complex interactions between plant roots, soil constituents and microorganisms. We discuss the current rhizosphere research challenges and knowledge gaps, as well as perspectives and approaches using newly available state-of-the-art toolboxes. These new approaches and methodologies allow the study of rhizosphere processes and properties, and rhizosphere as a central component of ecosystems and biogeochemical cycles.« less

New understanding of rhizosphere processes enabled by advances in molecular and spatially resolved techniques

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

Hess, Nancy J.; Paša-Tolić, Ljiljana; Bailey, Vanessa L.

Understanding the role played by microorganisms within soil systems is challenged by the unique intersection of physics, chemistry, mineralogy and biology in fostering habitat for soil microbial communities. To address these challenges will require observations across multiple spatial and temporal scales to capture the dynamics and emergent behavior from complex and interdependent processes. The heterogeneity and complexity of the rhizosphere require advanced techniques that press the simultaneous frontiers of spatial resolution, analyte sensitivity and specificity, reproducibility, large dynamic range, and high throughput. Fortunately many exciting technical advancements are now available to inform and guide the development of new hypotheses. Themore » aim of this Special issue is to provide a holistic view of the rhizosphere in the perspective of modern molecular biology methodologies that enabled a highly-focused, detailed view on the processes in the rhizosphere, including numerous, strong and complex interactions between plant roots, soil constituents and microorganisms. We discuss the current rhizosphere research challenges and knowledge gaps, as well as perspectives and approaches using newly available state-of-the-art toolboxes. These new approaches and methodologies allow the study of rhizosphere processes and properties, and rhizosphere as a central component of ecosystems and biogeochemical cycles.« less

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

Hess, Nancy J.; Pasa-Tolic, Ljiljana; Bailey, Vanessa L.

Understanding the role played by microorganisms within soil systems is challenged by the unique intersection of physics, chemistry, mineralogy and biology in fostering habitat for soil microbial communities. To address these challenges will require observations across multiple spatial and temporal scales to capture the dynamics and emergent behavior from complex and interdependent processes. The heterogeneity and complexity of the rhizosphere require advanced techniques that press the simultaneous frontiers of spatial resolution, analyte sensitivity and specificity, reproducibility, large dynamic range, and high throughput. Fortunately many exciting technical advancements are now available to inform and guide the development of new hypotheses. Themore » aim of this Special issue is to provide a holistic view of the rhizosphere in the perspective of modern molecular biology methodologies that enabled a highly-focused, detailed view on the processes in the rhizosphere, including numerous, strong and complex interactions between plant roots, soil constituents and microorganisms. We discuss the current rhizosphere research challenges and knowledge gaps, as well as perspectives and approaches using newly available state-of-the-art toolboxes. These new approaches and methodologies allow the study of rhizosphere processes and properties, and rhizosphere as a central component of ecosystems and biogeochemical cycles.« less

Superparamagnetic Iron Oxide Nanoparticles: Promises for Diagnosis and Treatment of Multiple Sclerosis

PubMed Central

2011-01-01

Smart superparamagnetic iron oxide nanoparticles (SPIONs) are the most promising candidate for theragnosis (i.e., diagnosis and treatment) of multiple sclerosis. A deep understanding of the dynamics of the in vivo neuropathology of multiple sclerosis can be achieved by improving the efficiency of various medical techniques (e.g., positron emission tomography and magnetic resonance imaging) using multimodal SPIONs. In this Review, recent advances and challenges in the development of smart SPIONs for theragnostic applications are comprehensively described. In addition, critical outlines of emerging developments are provided from the points of view of both clinicians and nanotechnologists. PMID:22778862

Floods and climate: emerging perspectives for flood risk assessment and management

NASA Astrophysics Data System (ADS)

Merz, B.; Aerts, J.; Arnbjerg-Nielsen, K.; Baldi, M.; Becker, A.; Bichet, A.; Blöschl, G.; Bouwer, L. M.; Brauer, A.; Cioffi, F.; Delgado, J. M.; Gocht, M.; Guzzetti, F.; Harrigan, S.; Hirschboeck, K.; Kilsby, C.; Kron, W.; Kwon, H.-H.; Lall, U.; Merz, R.; Nissen, K.; Salvatti, P.; Swierczynski, T.; Ulbrich, U.; Viglione, A.; Ward, P. J.; Weiler, M.; Wilhelm, B.; Nied, M.

2014-07-01

Flood estimation and flood management have traditionally been the domain of hydrologists, water resources engineers and statisticians, and disciplinary approaches abound. Dominant views have been shaped; one example is the catchment perspective: floods are formed and influenced by the interaction of local, catchment-specific characteristics, such as meteorology, topography and geology. These traditional views have been beneficial, but they have a narrow framing. In this paper we contrast traditional views with broader perspectives that are emerging from an improved understanding of the climatic context of floods. We come to the following conclusions: (1) extending the traditional system boundaries (local catchment, recent decades, hydrological/hydraulic processes) opens up exciting possibilities for better understanding and improved tools for flood risk assessment and management. (2) Statistical approaches in flood estimation need to be complemented by the search for the causal mechanisms and dominant processes in the atmosphere, catchment and river system that leave their fingerprints on flood characteristics. (3) Natural climate variability leads to time-varying flood characteristics, and this variation may be partially quantifiable and predictable, with the perspective of dynamic, climate-informed flood risk management. (4) Efforts are needed to fully account for factors that contribute to changes in all three risk components (hazard, exposure, vulnerability) and to better understand the interactions between society and floods. (5) Given the global scale and societal importance, we call for the organization of an international multidisciplinary collaboration and data-sharing initiative to further understand the links between climate and flooding and to advance flood research.

The developmental dynamics of behavioral growth processes in rodent egocentric and allocentric space.

PubMed

Golani, Ilan

2012-06-01

In this review I focus on how three methodological principles advocated by Philip Teitelbaum influenced my work to this day: that similar principles of organization should be looked for in ontogeny and recovery of function; that the order of emergence of behavioral components provides a view on the organization of that behavior; and that the components of behavior should be exhibited by the animal itself in relatively pure form. I start by showing how these principles influenced our common work on the developmental dynamics of rodent egocentric space, and then proceed to describe how these principles affected my work with Yoav Benjamini and others on the developmental dynamics of rodent allocentric space. We analyze issues traditionally addressed by physiological psychologists with methods borrowed from ethology, EW (Eshkol-Wachman) movement notation, dynamical systems and exploratory data analysis. Then we show how the natural origins of axes embodied by the behavior of the organism itself, are used by us as the origins of axes for the measurement of the developmental moment-by-moment dynamics of behavior. Using this methodology we expose similar principles of organization across situations, species and preparations, provide a developmental view on the organization of behavior, expose the natural components of behavior in relatively pure form, and reveal how low level primitives generate higher level constructs. Advances in tracking technology should allow us to study how movements in egocentric and allocentric spaces interlace. Tracking of multi-limb coordination, progress in online recording of neural activity in freely moving animals, and the unprecedented accumulation of genetically engineered mouse preparations makes the behavioral ground plan exposed in this review essential for a systematic study of the brain/behavior interface. Copyright © 2012 Elsevier B.V. All rights reserved.

23. VIEW, LOOKING SOUTH, SHOWING GASOLINEPOWERED EMERGENCY GENERATOR, WITH MAIN ...

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

23. VIEW, LOOKING SOUTH, SHOWING GASOLINE-POWERED EMERGENCY GENERATOR, WITH MAIN TRANSMISSION AT LEFT FOREGROUND - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

14 CFR 25.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

....562 Emergency landing dynamic conditions. (a) The seat and restraint system in the airplane must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 25... successfully complete dynamic tests or be demonstrated by rational analysis based on dynamic tests of a similar...

14 CFR 27.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 27... Conditions § 27.562 Emergency landing dynamic conditions. (a) The rotorcraft, although it may be damaged in... must successfully complete dynamic tests or be demonstrated by rational analysis based on dynamic tests...

14 CFR 29.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 29... Conditions § 29.562 Emergency landing dynamic conditions. (a) The rotorcraft, although it may be damaged in a... landing must successfully complete dynamic tests or be demonstrated by rational analysis based on dynamic...

An Atomistic View of Amyloidogenic Self-assembly: Structure and Dynamics of Heterogeneous Conformational States in the Pre-nucleation Phase

PubMed Central

Matthes, Dirk; Gapsys, Vytautas; Brennecke, Julian T.; de Groot, Bert L.

2016-01-01

The formation of well-defined filamentous amyloid structures involves a polydisperse collection of oligomeric states for which relatively little is known in terms of structural organization. Here we use extensive, unbiased explicit solvent molecular dynamics (MD) simulations to investigate the structural and dynamical features of oligomeric aggregates formed by a number of highly amyloidogenic peptides at atomistic resolution on the μs time scale. A consensus approach has been adopted to analyse the simulations in multiple force fields, yielding an in-depth characterization of pre-fibrillar oligomers and their global and local structure properties. A collision cross section analysis revealed structurally heterogeneous aggregate ensembles for the individual oligomeric states that lack a single defined quaternary structure during the pre-nucleation phase. To gain insight into the conformational space sampled in early aggregates, we probed their substructure and found emerging β-sheet subunit layers and a multitude of ordered intermolecular β-structure motifs with growing aggregate size. Among those, anti-parallel out-of-register β-strands compatible with toxic β-barrel oligomers were particularly prevalent already in smaller aggregates and formed prior to ordered fibrillar structure elements. Notably, also distinct fibril-like conformations emerged in the oligomeric state and underscore the notion that pre-nucleated oligomers serve as a critical intermediate step on-pathway to fibrils. PMID:27616019

Cellular reprogramming dynamics follow a simple 1D reaction coordinate

NASA Astrophysics Data System (ADS)

Teja Pusuluri, Sai; Lang, Alex H.; Mehta, Pankaj; Castillo, Horacio E.

2018-01-01

Cellular reprogramming, the conversion of one cell type to another, induces global changes in gene expression involving thousands of genes, and understanding how cells globally alter their gene expression profile during reprogramming is an ongoing problem. Here we reanalyze time-course data on cellular reprogramming from differentiated cell types to induced pluripotent stem cells (iPSCs) and show that gene expression dynamics during reprogramming follow a simple 1D reaction coordinate. This reaction coordinate is independent of both the time it takes to reach the iPSC state as well as the details of the experimental protocol used. Using Monte-Carlo simulations, we show that such a reaction coordinate emerges from epigenetic landscape models where cellular reprogramming is viewed as a ‘barrier-crossing’ process between cell fates. Overall, our analysis and model suggest that gene expression dynamics during reprogramming follow a canonical trajectory consistent with the idea of an ‘optimal path’ in gene expression space for reprogramming.

Modeling Heterogeneity in Momentary Interpersonal and Affective Dynamic Processes in Borderline Personality Disorder

PubMed Central

Wright, Aidan G. C.; Hallquist, Michael N.; Stepp, Stephanie D.; Scott, Lori N.; Beeney, Joseph E.; Lazarus, Sophie A.; Pilkonis, Paul A.

2016-01-01

Borderline personality disorder (BPD) is a diagnosis defined by impairments in several dynamic processes (e.g., interpersonal relating, affect regulation, behavioral control). Theories of BPD emphasize that these impairments appear in specific contexts, and emerging results confirm this view. At the same time, BPD is a complex construct that encompasses individuals with heterogeneous pathology. These features—dynamic processes, situational specificity, and individual heterogeneity—pose significant assessment challenges. In the current study, we demonstrate assessment and analytic methods that capture both between-person differences and within-person changes over time. Twenty-five participants diagnosed with BPD completed event-contingent, ambulatory assessment protocols over 21 days. We used p-technique factor analyses to identify person-specific psychological structures consistent with clinical theories of personality. Five exemplar cases are selected and presented in detail to showcase the potential utility of these methods. The presented cases' factor structures reflect not only heterogeneity but also suggest points of convergence. The factors also demonstrated significant associations with important clinical targets (self-harm, interpersonal violence). PMID:27317561

Cultural Differences in Chinese American and European American Children's Drawing Skills over Time

ERIC Educational Resources Information Center

Huntsinger, Carol S.; Jose, Paul E.; Krieg, Dana Balsink; Luo, Zupei

2011-01-01

Parents and early childhood teachers in Chinese societies and the United States have had dissimilar views about appropriate art instruction for young children. The Chinese view is that creativity will emerge after children have been taught essential drawing skills. The American view has been that children's drawing skills emerge naturally and that…

The quest for a unified view of bacterial land colonization

PubMed Central

Wu, Hao; Fang, Yongjun; Yu, Jun; Zhang, Zhang

2014-01-01

Exploring molecular mechanisms underlying bacterial water-to-land transition represents a critical start toward a better understanding of the functioning and stability of the terrestrial ecosystems. Here, we perform comprehensive analyses based on a large variety of bacteria by integrating taxonomic, phylogenetic and metagenomic data, in the quest for a unified view that elucidates genomic, evolutionary and ecological dynamics of the marine progenitors in adapting to nonaquatic environments. We hypothesize that bacterial land colonization is dominated by a single-gene sweep, that is, the emergence of dnaE2 derived from an early duplication event of the primordial dnaE, followed by a series of niche-specific genomic adaptations, including GC content increase, intensive horizontal gene transfer and constant genome expansion. In addition, early bacterial radiation may be stimulated by an explosion of land-borne hosts (for example, plants and animals) after initial land colonization events. PMID:24451209

A psychodynamic model of behavior after acute central nervous system damage.

PubMed

Groswasser, Z; Stern, M J

1998-02-01

This article describes a conceptual psychodynamic model for understanding the neurobehavioral manifestations of acute central nervous system damage (ACNSD) displayed by patients during the rehabilitation process. According to the proposed model, patientsO behavioral responses are viewed as their only means of emotional expression and therefore may not be considered entirely abnormal when viewed from the perspective of patientsO interpersonal contexts. An improved understanding of the dynamic processes through which recovering patients with ACNSD journey may lead to better interaction between the patient and the therapeutic environment, the interdisciplinary team, and family members. Combining this proposed psychodynamic model with an emerging understanding of the neurobehavioral foundations of aggression and depression may also lead to a more rational approach to intervention with various psychopharmacologic agents. During the rehabilitation process, understanding patients' cognitive deficits, motivational drives, and emotional needs and proper implementation of medical and environmental treatment can ultimately lead to a better psychosocial outcome.

Emerging structural insights into glycoprotein quality control coupled with N-glycan processing in the endoplasmic reticulum.

PubMed

Satoh, Tadashi; Yamaguchi, Takumi; Kato, Koichi

2015-01-30

In the endoplasmic reticulum (ER), the sugar chain is initially introduced onto newly synthesized proteins as a triantennary tetradecasaccharide (Glc3Man9GlcNAc2). The attached oligosaccharide chain is subjected to stepwise trimming by the actions of specific glucosidases and mannosidases. In these processes, the transiently expressed N-glycans, as processing intermediates, function as signals for the determination of glycoprotein fates, i.e., folding, transport, or degradation through interactions of a series of intracellular lectins. The monoglucosylated glycoforms are hallmarks of incompletely folded states of glycoproteins in this system, whereas the outer mannose trimming leads to ER-associated glycoprotein degradation. This review outlines the recently emerging evidence regarding the molecular and structural basis of this glycoprotein quality control system, which is regulated through dynamic interplay among intracellular lectins, glycosidases, and glycosyltransferase. Structural snapshots of carbohydrate-lectin interactions have been provided at the atomic level using X-ray crystallographic analyses. Conformational ensembles of uncomplexed triantennary high-mannose-type oligosaccharides have been characterized in a quantitative manner using molecular dynamics simulation in conjunction with nuclear magnetic resonance spectroscopy. These complementary views provide new insights into glycoprotein recognition in quality control coupled with N-glycan processing.

Evolution in action: climate change, biodiversity dynamics and emerging infectious disease

PubMed Central

Hoberg, Eric P.; Brooks, Daniel R.

2015-01-01

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host–parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly observable in real time. The emerging Stockholm Paradigm resolves this paradox: Ecological Fitting (EF)—phenotypic flexibility and phylogenetic conservatism in traits related to resource use, most notably host preference—provides many opportunities for rapid host switching in changing environments, without the evolution of novel host-utilization capabilities. Host shifts via EF fuel the expansion phase of the Oscillation Hypothesis of host range and speciation and, more generally, the generation of novel combinations of interacting species within the Geographic Mosaic Theory of Coevolution. In synergy, an environmental dynamic of Taxon Pulses establishes an episodic context for host and geographical colonization. PMID:25688014

Business Policy or Strategic Management: A Broader View for an Emerging Discipline. Paper No. 371.

ERIC Educational Resources Information Center

Schendel, Dan E.; Hatten, Kenneth J.

Generally, business policy is thought of as a course rather than as a field of study or as a broad discipline. This view has limited the development of substantive knowledge unique to the problems of total enterprise management. Evidence indicates that a broader view of these problems and new opportunities for further development are emerging.…

A comparison between digital images viewed on a picture archiving and communication system diagnostic workstation and on a PC-based remote viewing system by emergency physicians.

PubMed

Parasyn, A; Hanson, R M; Peat, J K; De Silva, M

1998-02-01

Picture Archiving and Communication Systems (PACS) make possible the viewing of radiographic images on computer workstations located where clinical care is delivered. By the nature of their work this feature is particularly useful for emergency physicians who view radiographic studies for information and use them to explain results to patients and their families. However, the high cost of PACS diagnostic workstations with fuller functionality places limits on the number of and therefore the accessibility to workstations in the emergency department. This study was undertaken to establish how well less expensive personal computer-based workstations would work to support these needs of emergency physicians. The study compared the outcome of observations by 5 emergency physicians on a series of radiographic studies containing subtle abnormalities displayed on both a PACS diagnostic workstation and on a PC-based workstation. The 73 digitized radiographic studies were randomly arranged on both types of workstation over four separate viewing sessions for each emergency physician. There was no statistical difference between a PACS diagnostic workstation and a PC-based workstation in this trial. The mean correct ratings were 59% on the PACS diagnostic workstations and 61% on the PC-based workstations. These findings also emphasize the need for prompt reporting by a radiologist.

Emerging Computer Media: On Image Interaction

NASA Astrophysics Data System (ADS)

Lippman, Andrew B.

1982-01-01

Emerging technologies such as inexpensive, powerful local computing, optical digital videodiscs, and the technologies of human-machine interaction are initiating a revolution in both image storage systems and image interaction systems. This paper will present a review of new approaches to computer media predicated upon three dimensional position sensing, speech recognition, and high density image storage. Examples will be shown such as the Spatial Data Management Systems wherein the free use of place results in intuitively clear retrieval systems and potentials for image association; the Movie-Map, wherein inherently static media generate dynamic views of data, and conferencing work-in-progress wherein joint processing is stressed. Application to medical imaging will be suggested, but the primary emphasis is on the general direction of imaging and reference systems. We are passing the age of simple possibility of computer graphics and image porcessing and entering the age of ready usability.

Emerging importance of holobionts in evolution and in probiotics

PubMed Central

2013-01-01

The existence of microbe free animals or plants in nature is virtually impossible as they and plants have a certain degree of symbiotic association with microbes. This symbiotic association leads to the formation of holobiont (host and its symbionts). This mutual coexistence is not merely at the physical or chemical level but also at the genetic level leading to the emergence of the concept of hologenome (gene pool of host and its associated symbionts). The abundance of symbionts with the associated gene diversity contributes to the fitness of the holobiont under varying environmental conditions. The hologenome theory of evolution considers the dynamic holobiont as a single unit for natural selection and provides a more accommodating view of evolution blending Darwinism and Lamarkism. Additionally, holobionts are providing scientific basis to our understanding of the growing importance of probiotics in human health and in disease management. PMID:23694677

Dynamics of scene representations in the human brain revealed by magnetoencephalography and deep neural networks.

PubMed

Martin Cichy, Radoslaw; Khosla, Aditya; Pantazis, Dimitrios; Oliva, Aude

2017-06-01

Human scene recognition is a rapid multistep process evolving over time from single scene image to spatial layout processing. We used multivariate pattern analyses on magnetoencephalography (MEG) data to unravel the time course of this cortical process. Following an early signal for lower-level visual analysis of single scenes at ~100ms, we found a marker of real-world scene size, i.e. spatial layout processing, at ~250ms indexing neural representations robust to changes in unrelated scene properties and viewing conditions. For a quantitative model of how scene size representations may arise in the brain, we compared MEG data to a deep neural network model trained on scene classification. Representations of scene size emerged intrinsically in the model, and resolved emerging neural scene size representation. Together our data provide a first description of an electrophysiological signal for layout processing in humans, and suggest that deep neural networks are a promising framework to investigate how spatial layout representations emerge in the human brain. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Complex Dynamic Systems View on Conceptual Change: How a Picture of Students' Intuitive Conceptions Accrue from Dynamically Robust Task Dependent Learning Outcomes

ERIC Educational Resources Information Center

Koponen, Ismo T.; Kokkonen, Tommi; Nousiainen, Maiji

2017-01-01

We discuss here conceptual change and the formation of robust learning outcomes from the viewpoint of complex dynamic systems (CDS). The CDS view considers students' conceptions as context dependent and multifaceted structures which depend on the context of their application. In the CDS view the conceptual patterns (i.e. intuitive conceptions…

Multiple-viewing-zone integral imaging using a dynamic barrier array for three-dimensional displays.

PubMed

Choi, Heejin; Min, Sung-Wook; Jung, Sungyong; Park, Jae-Hyeung; Lee, Byoungho

2003-04-21

In spite of many advantages of integral imaging, the viewing zone in which an observer can see three-dimensional images is limited within a narrow range. Here, we propose a novel method to increase the number of viewing zones by using a dynamic barrier array. We prove our idea by fabricating and locating the dynamic barrier array between a lens array and a display panel. By tilting the barrier array, it is possible to distribute images for each viewing zone. Thus, the number of viewing zones can be increased with an increment of the states of the barrier array tilt.

Population growth rates: issues and an application.

PubMed Central

Godfray, H Charles J; Rees, Mark

2002-01-01

Current issues in population dynamics are discussed in the context of The Royal Society Discussion Meeting 'Population growth rate: determining factors and role in population regulation'. In particular, different views on the centrality of population growth rates to the study of population dynamics and the role of experiments and theory are explored. Major themes emerging include the role of modern statistical techniques in bringing together experimental and theoretical studies, the importance of long-term experimentation and the need for ecology to have model systems, and the value of population growth rate as a means of understanding and predicting population change. The last point is illustrated by the application of a recently introduced technique, integral projection modelling, to study the population growth rate of a monocarpic perennial plant, its elasticities to different life-history components and the evolution of an evolutionarily stable strategy size at flowering. PMID:12396521

Dynamics of problem setting and framing in citizen discussions on synthetic biology.

PubMed

Betten, Afke Wieke; Broerse, Jacqueline E W; Kupper, Frank

2018-04-01

Synthetic biology is an emerging scientific field where engineers and biologists design and build biological systems for various applications. Developing synthetic biology responsibly in the public interest necessitates a meaningful societal dialogue. In this article, we argue that facilitating such a dialogue requires an understanding of how people make sense of synthetic biology. We performed qualitative research to unravel the underlying dynamics of problem setting and framing in citizen discussions on synthetic biology. We found that most people are not inherently for or against synthetic biology as a technology or development in itself, but that their perspectives are framed by core values about our relationships with science and technology and that sensemaking is much dependent on the context and general feelings of (dis)content. Given that there are many assumptions focused on a more binary idea of the public's view, we emphasize the need for frame awareness and understanding in a meaningful dialogue.

A mathematical basis for plant patterning derived from physico-chemical phenomena.

PubMed

Beleyur, Thejasvi; Abdul Kareem, Valiya Kadavu; Shaji, Anil; Prasad, Kalika

2013-04-01

The position of leaves and flowers along the stem axis generates a specific pattern, known as phyllotaxis. A growing body of evidence emerging from recent computational modeling and experimental studies suggests that regulators controlling phyllotaxis are chemical, e.g. the plant growth hormone auxin and its dynamic accumulation pattern by polar auxin transport, and physical, e.g. mechanical properties of the cell. Here we present comprehensive views on how chemical and physical properties of cells regulate the pattern of leaf initiation. We further compare different computational modeling studies to understand their scope in reproducing the observed patterns. Despite a plethora of experimental studies on phyllotaxis, understanding of molecular mechanisms of pattern initiation in plants remains fragmentary. Live imaging of growth dynamics and physicochemical properties at the shoot apex of mutants displaying stable changes from one pattern to another should provide mechanistic insights into organ initiation patterns. Copyright © 2013 WILEY Periodicals, Inc.

Technologies for imaging neural activity in large volumes

PubMed Central

Ji, Na; Freeman, Jeremy; Smith, Spencer L.

2017-01-01

Neural circuitry has evolved to form distributed networks that act dynamically across large volumes. Collecting data from individual planes, conventional microscopy cannot sample circuitry across large volumes at the temporal resolution relevant to neural circuit function and behaviors. Here, we review emerging technologies for rapid volume imaging of neural circuitry. We focus on two critical challenges: the inertia of optical systems, which limits image speed, and aberrations, which restrict the image volume. Optical sampling time must be long enough to ensure high-fidelity measurements, but optimized sampling strategies and point spread function engineering can facilitate rapid volume imaging of neural activity within this constraint. We also discuss new computational strategies for the processing and analysis of volume imaging data of increasing size and complexity. Together, optical and computational advances are providing a broader view of neural circuit dynamics, and help elucidate how brain regions work in concert to support behavior. PMID:27571194

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.

Stochastic dynamics for idiotypic immune networks

NASA Astrophysics Data System (ADS)

Barra, Adriano; Agliari, Elena

2010-12-01

In this work we introduce and analyze the stochastic dynamics obeyed by a model of an immune network recently introduced by the authors. We develop Fokker-Planck equations for the single lymphocyte behavior and coarse grained Langevin schemes for the averaged clone behavior. After showing agreement with real systems (as a short path Jerne cascade), we suggest, both with analytical and numerical arguments, explanations for the generation of (metastable) memory cells, improvement of the secondary response (both in the quality and quantity) and bell shaped modulation against infections as a natural behavior. The whole emerges from the model without being postulated a-priori as it often occurs in second generation immune networks: so the aim of the work is to present some out-of-equilibrium features of this model and to highlight mechanisms which can replace a-priori assumptions in view of further detailed analysis in theoretical systemic immunology.

COMSAC: Computational Methods for Stability and Control. Part 1

NASA Technical Reports Server (NTRS)

Fremaux, C. Michael (Compiler); Hall, Robert M. (Compiler)

2004-01-01

Work on stability and control included the following reports:Introductory Remarks; Introduction to Computational Methods for Stability and Control (COMSAC); Stability & Control Challenges for COMSAC: a NASA Langley Perspective; Emerging CFD Capabilities and Outlook A NASA Langley Perspective; The Role for Computational Fluid Dynamics for Stability and Control:Is it Time?; Northrop Grumman Perspective on COMSAC; Boeing Integrated Defense Systems Perspective on COMSAC; Computational Methods in Stability and Control:WPAFB Perspective; Perspective: Raytheon Aircraft Company; A Greybeard's View of the State of Aerodynamic Prediction; Computational Methods for Stability and Control: A Perspective; Boeing TacAir Stability and Control Issues for Computational Fluid Dynamics; NAVAIR S&C Issues for CFD; An S&C Perspective on CFD; Issues, Challenges & Payoffs: A Boeing User s Perspective on CFD for S&C; and Stability and Control in Computational Simulations for Conceptual and Preliminary Design: the Past, Today, and Future?

Landauer’s formula with finite-time relaxation: Kramers’ crossover in electronic transport

DOE PAGES

Gruss, Daniel; Velizhanin, Kirill A.; Zwolak, Michael

2016-04-20

Landauer’s formula is the standard theoretical tool to examine ballistic transport in nano- and meso-scale junctions, but it necessitates that any variation of the junction with time must be slow compared to characteristic times of the system, e.g., the relaxation time of local excitations. Transport through structurally dynamic junctions is, however, increasingly of interest for sensing, harnessing fluctuations, and real-time control. Here, we calculate the steady-state current when relaxation of electrons in the reservoirs is present and demonstrate that it gives rise to three regimes of behavior: weak relaxation gives a contact-limited current; strong relaxation localizes electrons, distorting their naturalmore » dynamics and reducing the current; and in an intermediate regime the Landauer view of the system only is recovered. Lastly, we also demonstrate that a simple equation of motion emerges, which is suitable for efficiently simulating time-dependent transport.« less

Cultural values and immigrant entrepreneurship: the Chinese in Singapore.

PubMed

Chan, K B; Chiang, S N

1994-01-01

"It is the intent of this paper to examine the interrelationships between early socialisation into core Chinese cultural values, international migration and Chinese immigrant entrepreneurship.... It is through a developmental socialisation process by which [cultural] values are articulated in family and kin network dynamics that social organisations begin to develop and define what is popularly understood as the 'Chinese way of doing business'. We argue that among the overseas Chinese, this way of doing business must be viewed historically and developmentally, as it is intimately intertwined with transmigration experiences and their consequences in shaping values necessary for the emergence and development of entrepreneurship." (SUMMARY IN FRE AND SPA) excerpt

The edge of chaos: A nonlinear view of psychoanalytic technique.

PubMed

Galatzer-Levy, Robert M

2016-04-01

The field of nonlinear dynamics (or chaos theory) provides ways to expand concepts of psychoanalytic process that have implications for the technique of psychoanalysis. This paper describes how concepts of "the edge of chaos," emergence, attractors, and coupled oscillators can help shape analytic technique resulting in an approach to doing analysis which is at the same time freer and more firmly based in an enlarged understanding of the ways in which psychoanalysis works than some current recommendation about technique. Illustrations from a lengthy analysis of an analysand with obsessive-compulsive disorder show this approach in action. Copyright © 2016 Institute of Psychoanalysis.

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

Cheng, Hai-Ping

The Sanibel Symposium 2014 was held February 16-21, 2014, at the King and Prince, St. Simons Island, GA. It was successful in bringing condensed-matter physicists and quantum chemists together productively to drive the emergence of those specialties. The Symposium had a significant role in preparing a whole generation of quantum theorists. The 54th Sanibel meeting looked to the future in two ways. We had 360⁰-View sessions to honor the exceptional contributions of Rodney Bartlett (70), Bill Butler (70), Yngve Öhrn (80), Fritz Schaefer (70), and Malcolm Stocks (70). The work of these five has greatly impacted several generations of quantummore » chemists and condensed matter physicists. The “360⁰” is the sum of their ages. More significantly, it symbolizes a panoramic view of critical developments and accomplishments in theoretical and computational chemistry and physics oriented toward the future. Thus, two of the eight 360⁰-View sessions focused specifically on younger scientists. The 360⁰-View program was the major component of the 2014 Sanibel meeting. Another four sessions included a sub-symposium on ab initio Simulations at Extreme Conditions, with focus on getting past the barriers of present-day Born-Oppenheimer molecular dynamics by advances in finite-temperature density functional theory, orbital-free DFT, and new all-numerical approaches.« less

The First View Concept: introduction of industrial flow techniques into emergency medicine organization.

PubMed

Hogan, Barbara; Rasche, Christoph; von Reinersdorff, Andrea Braun

2012-06-01

The number of patients seeking treatment in emergency departments is rising, although many governments are seeking to reduce expenditure on health. Emergency departments must achieve more with the same resources or perform the same functions with fewer resources. Patients demand higher emergency clinical care quality, with low waiting times viewed as a key quality criterion by many patients. The objective of this study was to create an improved working system in emergency departments that cuts patient waiting times for first specialty physician contact. Techniques from industrial flow management were applied to the working process of an emergency department and the concept was named 'First View.' A total of 3269 patient contacts using the First View Concept during a treatment month showed statistical significance. Before introduction, a total 3230 patients in a comparative treatment month had a median waiting time before the first doctor contact of 47.6 min, a first quartile waiting time of 36.1 min, and a third quartile waiting time of 62.7 min. After introduction, 3269 patients had a median waiting time before first specialty physician contact of 11.2 min, a first quartile waiting time of 9.1 min, and a third quartile waiting time of 15.2 min. Industrial flow concepts can achieve significant improvements in emergency department workflows in countries in which sufficient numbers of specialty physicians are available. More attention to the organization of emergency department working processes is needed, especially involving lean management.

Exploring the views of emergency department staff on the use of videoconferencing for mental health emergencies in southwestern Ontario.

PubMed

Pangka, Kyle R; Chandrasena, Ranjith; Wijeratne, Nishardi; Mann, Miriam

2015-01-01

Patients presenting to a rural emergency department (ED) with mental health symptoms have difficulty accessing services of mental health professionals [1,2]. Videoconferencing (VC) has been found to improve patient access to health services that require specialist care in rural EDs [3,4,5]. Although previous studies highlight the benefit of using VC for patients presenting with mental health emergencies, no study has investigated the current views and use of VC for mental health emergencies in EDs in Southwestern Ontario [3,5,6]. To explore the views of ED staff regarding the use of VC in mental health emergencies, structured telephone interviews were conducted with representatives from EDs in the Erie St. Clair and Southwest Local Health Integration Networks (LHIN). Participants noted that using VC for mental health emergencies may improve patient experience and benefit crisis response teams. VC was perceived by some participants as a means to expedite the direct assessment of a patient presenting with a mental health emergency by a mental health specialist. However several participants stated that using VC for mental health emergencies strains ED resources. Lack of use and difficulty accessing a psychiatrist were identified as potential barriers to implementing the use of VC for mental health emergencies.

Pathogenic landscapes: Interactions between land, people, disease vectors, and their animal hosts

PubMed Central

2010-01-01

Background Landscape attributes influence spatial variations in disease risk or incidence. We present a review of the key findings from eight case studies that we conducted in Europe and West Africa on the impact of land changes on emerging or re-emerging vector-borne diseases and/or zoonoses. The case studies concern West Nile virus transmission in Senegal, tick-borne encephalitis incidence in Latvia, sandfly abundance in the French Pyrenees, Rift Valley Fever in the Ferlo (Senegal), West Nile Fever and the risk of malaria re-emergence in the Camargue, and rodent-borne Puumala hantavirus and Lyme borreliosis in Belgium. Results We identified general principles governing landscape epidemiology in these diverse disease systems and geographic regions. We formulated ten propositions that are related to landscape attributes, spatial patterns and habitat connectivity, pathways of pathogen transmission between vectors and hosts, scale issues, land use and ownership, and human behaviour associated with transmission cycles. Conclusions A static view of the "pathogenecity" of landscapes overlays maps of the spatial distribution of vectors and their habitats, animal hosts carrying specific pathogens and their habitat, and susceptible human hosts and their land use. A more dynamic view emphasizing the spatial and temporal interactions between these agents at multiple scales is more appropriate. We also highlight the complementarity of the modelling approaches used in our case studies. Integrated analyses at the landscape scale allows a better understanding of interactions between changes in ecosystems and climate, land use and human behaviour, and the ecology of vectors and animal hosts of infectious agents. PMID:20979609

Dynamics of 3D view invariance in monkey inferotemporal cortex

PubMed Central

Ratan Murty, N. Apurva

2015-01-01

Rotations in depth are challenging for object vision because features can appear, disappear, be stretched or compressed. Yet we easily recognize objects across views. Are the underlying representations view invariant or dependent? This question has been intensely debated in human vision, but the neuronal representations remain poorly understood. Here, we show that for naturalistic objects, neurons in the monkey inferotemporal (IT) cortex undergo a dynamic transition in time, whereby they are initially sensitive to viewpoint and later encode view-invariant object identity. This transition depended on two aspects of object structure: it was strongest when objects foreshortened strongly across views and were similar to each other. View invariance in IT neurons was present even when objects were reduced to silhouettes, suggesting that it can arise through similarity between external contours of objects across views. Our results elucidate the viewpoint debate by showing that view invariance arises dynamically in IT neurons out of a representation that is initially view dependent. PMID:25609108

The behavioral dynamics of clinical trials.

PubMed

Leventhal, H; Nerenz, D R; Leventhal, E A; Love, R R; Bendena, L M

1991-01-01

Two ways of approaching the design of long-term clinical trials are presented and contrasted. The first, termed the "static" view, emphasizes close adherence to formal rules of study design. The second, termed the "dynamic" view, emphasizes the behavioral aspects of patient participation in trials of long duration. The dynamic view is discussed in detail, with discussion of how recruitment of participants, random assignment to conditions, compliance with protocol, and measurement of outcomes are affected by behavioral dynamics. Data from a recently completed tamoxifen toxicity trial are used to illustrate the points and to focus the discussion of behavioral dynamics on the design of a chemoprevention trial for breast cancer using tamoxifen.

VIEW LOOKING SOUTHWEST AT BUILDING 122 DURING CONSTRUCTION. BUILDING 122, ...

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

VIEW LOOKING SOUTHWEST AT BUILDING 122 DURING CONSTRUCTION. BUILDING 122, THE EMERGENCY MEDICAL BUILDING, WAS ONE OF THE ORIGINAL STRUCTURES AT THE ROCKY FLATS PLANT. (5/29/52) - Rocky Flats Plant, Emergency Medical Services Facility, Southwest corner of Central & Third Avenues, Golden, Jefferson County, CO

A role for low-order system dynamics models in urban health policy making.

PubMed

Newell, Barry; Siri, José

2016-10-01

Cities are complex adaptive systems whose responses to policy initiatives emerge from feedback interactions between their parts. Urban policy makers must routinely deal with both detail and dynamic complexity, coupled with high levels of diversity, uncertainty and contingency. In such circumstances, it is difficult to generate reliable predictions of health-policy outcomes. In this paper we explore the potential for low-order system dynamics (LOSD) models to make a contribution towards meeting this challenge. By definition, LOSD models have few state variables (≤5), illustrate the non-linear effects caused by feedback and accumulation, and focus on endogenous dynamics generated within well-defined boundaries. We suggest that experience with LOSD models can help practitioners to develop an understanding of basic principles of system dynamics, giving them the ability to 'see with new eyes'. Because efforts to build a set of LOSD models can help a transdisciplinary group to develop a shared, coherent view of the problems that they seek to tackle, such models can also become the foundations of 'powerful ideas'. Powerful ideas are conceptual metaphors that provide the members of a policy-making group with the a priori shared context required for effective communication, the co-production of knowledge, and the collaborative development of effective public health policies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evolution in action: climate change, biodiversity dynamics and emerging infectious disease.

PubMed

Hoberg, Eric P; Brooks, Daniel R

2015-04-05

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host-parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly observable in real time. The emerging Stockholm Paradigm resolves this paradox: Ecological Fitting (EF)--phenotypic flexibility and phylogenetic conservatism in traits related to resource use, most notably host preference--provides many opportunities for rapid host switching in changing environments, without the evolution of novel host-utilization capabilities. Host shifts via EF fuel the expansion phase of the Oscillation Hypothesis of host range and speciation and, more generally, the generation of novel combinations of interacting species within the Geographic Mosaic Theory of Coevolution. In synergy, an environmental dynamic of Taxon Pulses establishes an episodic context for host and geographical colonization. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Biomolecular Dynamics: Order-Disorder Transitions and Energy Landscapes

PubMed Central

Whitford, Paul C.; Sanbonmatsu, Karissa Y.; Onuchic, José N.

2013-01-01

While the energy landscape theory of protein folding is now a widely accepted view for understanding how relatively-weak molecular interactions lead to rapid and cooperative protein folding, such a framework must be extended to describe the large-scale functional motions observed in molecular machines. In this review, we discuss 1) the development of the energy landscape theory of biomolecular folding, 2) recent advances towards establishing a consistent understanding of folding and function, and 3) emerging themes in the functional motions of enzymes, biomolecular motors, and other biomolecular machines. Recent theoretical, computational, and experimental lines of investigation are providing a very dynamic picture of biomolecular motion. In contrast to earlier ideas, where molecular machines were thought to function similarly to macroscopic machines, with rigid components that move along a few degrees of freedom in a deterministic fashion, biomolecular complexes are only marginally stable. Since the stabilizing contribution of each atomic interaction is on the order of the thermal fluctuations in solution, the rigid body description of molecular function must be revisited. An emerging theme is that functional motions encompass order-disorder transitions and structural flexibility provide significant contributions to the free-energy. In this review, we describe the biological importance of order-disorder transitions and discuss the statistical-mechanical foundation of theoretical approaches that can characterize such transitions. PMID:22790780

Face learning and the emergence of view-independent face recognition: an event-related brain potential study.

PubMed

Zimmermann, Friederike G S; Eimer, Martin

2013-06-01

Recognizing unfamiliar faces is more difficult than familiar face recognition, and this has been attributed to qualitative differences in the processing of familiar and unfamiliar faces. Familiar faces are assumed to be represented by view-independent codes, whereas unfamiliar face recognition depends mainly on view-dependent low-level pictorial representations. We employed an electrophysiological marker of visual face recognition processes in order to track the emergence of view-independence during the learning of previously unfamiliar faces. Two face images showing either the same or two different individuals in the same or two different views were presented in rapid succession, and participants had to perform an identity-matching task. On trials where both faces showed the same view, repeating the face of the same individual triggered an N250r component at occipito-temporal electrodes, reflecting the rapid activation of visual face memory. A reliable N250r component was also observed on view-change trials. Crucially, this view-independence emerged as a result of face learning. In the first half of the experiment, N250r components were present only on view-repetition trials but were absent on view-change trials, demonstrating that matching unfamiliar faces was initially based on strictly view-dependent codes. In the second half, the N250r was triggered not only on view-repetition trials but also on view-change trials, indicating that face recognition had now become more view-independent. This transition may be due to the acquisition of abstract structural codes of individual faces during face learning, but could also reflect the formation of associative links between sets of view-specific pictorial representations of individual faces. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cybersecurity Dynamics

DTIC Science & Technology

2014-08-20

of Cybersecurity Dynamics emerged. Intuitively, Cybersecurity Dynamics describes the evolution of cybersecurity state as caused by cyber attack...Dynamics emerged. Intuitively, Cybersecurity Dynamics describes the evolution of cybersecurity state as caused by cyber attack-defense interactions...evolution of cyberse- curity state as caused by cyber attack-defense interactions. By studying Cybersecurity Dynamics, we can characterize the

39. VIEW OF TRAINEE EMERGING FROM ON THE AIR LOCKS ...

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

39. VIEW OF TRAINEE EMERGING FROM ON THE AIR LOCKS INTO THE SUBMARINE ESCAPE TRAINING TANK. HIGH HOOKS STRADDLES DOOR AT LEFT, WHILE LOW HOOKS ASSISTS TRAINEE No date - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

Determination of Original Infection Source of H7N9 Avian Influenza by Dynamical Model

NASA Astrophysics Data System (ADS)

Zhang, Juan; Jin, Zhen; Sun, Gui-Quan; Sun, Xiang-Dong; Wang, You-Ming; Huang, Baoxu

2014-05-01

H7N9, a newly emerging virus in China, travels among poultry and human. Although H7N9 has not aroused massive outbreaks, recurrence in the second half of 2013 makes it essential to control the spread. It is believed that the most effective control measure is to locate the original infection source and cut off the source of infection from human. However, the original infection source and the internal transmission mechanism of the new virus are not totally clear. In order to determine the original infection source of H7N9, we establish a dynamical model with migratory bird, resident bird, domestic poultry and human population, and view migratory bird, resident bird, domestic poultry as original infection source respectively to fit the true dynamics during the 2013 pandemic. By comparing the date fitting results and corresponding Akaike Information Criterion (AIC) values, we conclude that migrant birds are most likely the original infection source. In addition, we obtain the basic reproduction number in poultry and carry out sensitivity analysis of some parameters.

A contemporary look at Hermann Hankel's 1861 pioneering work on Lagrangian fluid dynamics

NASA Astrophysics Data System (ADS)

Frisch, Uriel; Grimberg, Gérard; Villone, Barbara

2017-12-01

The present paper is a companion to the paper by Villone and Rampf (2017), titled "Hermann Hankel's On the general theory of motion of fluids, an essay including an English translation of the complete Preisschrift from 1861" together with connected documents [Eur. Phys. J. H 42, 557-609 (2017)]. Here we give a critical assessment of Hankel's work, which covers many important aspects of fluid dynamics considered from a Lagrangian-coordinates point of view: variational formulation in the spirit of Hamilton for elastic (barotropic) fluids, transport (we would now say Lie transport) of vorticity, the Lagrangian significance of Clebsch variables, etc. Hankel's work is also put in the perspective of previous and future work. Hence, the action spans about two centuries: from Lagrange's 1760-1761 Turin paper on variational approaches to mechanics and fluid mechanics problems to Arnold's 1966 founding paper on the geometrical/variational formulation of incompressible flow. The 22-year-old Hankel - who was to die 12 years later — emerges as a highly innovative master of mathematical fluid dynamics, fully deserving Riemann's assessment that his Preisschrift contains "all manner of good things."

Understanding the Chronology and Occupation Dynamics of Oversized Pit Houses in the Southern Brazilian Highlands.

PubMed

Gregorio de Souza, Jonas; Robinson, Mark; Corteletti, Rafael; Cárdenas, Macarena Lucia; Wolf, Sidnei; Iriarte, José; Mayle, Francis; DeBlasis, Paulo

2016-01-01

A long held view about the occupation of southern proto-Jê pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit House 1, Baggio I site (Cal. A.D. 1395-1650), Campo Belo do Sul, Santa Catarina state, Brazil. The stratigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Jê. As monumental pit houses start to be built, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamics and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America.

Understanding the Chronology and Occupation Dynamics of Oversized Pit Houses in the Southern Brazilian Highlands

PubMed Central

Gregorio de Souza, Jonas; Robinson, Mark; Corteletti, Rafael; Cárdenas, Macarena Lucia; Wolf, Sidnei; Iriarte, José; Mayle, Francis; DeBlasis, Paulo

2016-01-01

A long held view about the occupation of southern proto-Jê pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit House 1, Baggio I site (Cal. A.D. 1395–1650), Campo Belo do Sul, Santa Catarina state, Brazil. The stratigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Jê. As monumental pit houses start to be built, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamics and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America. PMID:27384341

When Black Holes Collide

NASA Technical Reports Server (NTRS)

Baker, John

2010-01-01

Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

Forces and thin water film drainage in deformable asymmetric nanoscale contacts.

PubMed

Schönherr, Holger

2015-01-27

Gas-liquid interfaces are omnipresent in daily life, and processes involving these interfaces are the basis for a broad range of applications that span from established industrial processes to modern microengineering, technology, and medical applications for diagnosis and treatment. Despite the rapid progress in understanding intermolecular forces at such interfaces from a theoretical point of view and, in particular, from an experimental point of view down to sub-nanometer length scales, the quantitative description of all relevant forces, particularly the hydrophobic interaction and the dynamic behavior of nanometer-scale confined water films, was until now unsatisfactory. This situation is particularly the case for the elusive description and understanding of the origins of the so-called hydrophobic interaction. For soft, deformable interfaces, such as those found in asymmetric contacts between gas bubbles and a solid, a complete picture has begun to emerge that has direct consequences for interfacial water at (bio)interfaces, functionalized gas microbubbles, surface nanobubbles, and beyond.

The Influence of Youth Music Television Viewership on Changes in Cigarette Use and Association with Smoking Peers: A Social Identity, Reinforcing Spirals Perspective

PubMed Central

Slater, Michael D.; Hayes, Andrew F.

2010-01-01

Prior research has found strong evidence of a prospective association between R movie exposure and teen smoking. Using parallel process latent-growth modeling, the present study examines prospective associations between viewing of music video channels on television (e.g., MTV and VH-1) and changes over time in smoking and association with smoking peers. Results showed that baseline viewing of music-oriented channels such as MTV and VH-1 robustly predicted increasing trajectories of smoking and of associating with smoking peers, even after application of a variety of controls including parent reports of monitoring behavior. These results are consistent with the arguments from the reinforcing spirals model that such media use serves as a means of developing emergent adolescent social identities consistent with associating with smoking peers and acquiring smoking and other risk behaviors; evidence also suggests that media choice in reinforcing spiral processes are dynamic and evolve as social identity evolves. PMID:21318085

Max Weber or Jesus Christ: in whose image?

PubMed

Fitzpatrick, A M; Gaylor, C C

1985-10-01

The bureaucratic model of organization and the model that emerges from the Gospel and Vatican Council II provide a stark contrast for Catholic health care administrators to ponder. As articulated by sociologist Max Weber, a bureaucracy is based on a hierarchical structure with sharply defined and protected levels of authority, centralized decision making, rules that govern personnel behavior, and an impersonalized view of employees that stresses their roles as functionaries. The Christian, Gospel-based model, on the other hand, places a premium on collegiality, shared authority, the mediation of conscience, the common good, and the work of the individual. Even though only a few will shape management policy in a large hospital, policymaking should be viewed as a service, a ministry that entails stewardship. Catholic health care leaders should reflect the spirit of collegiality by bringing various strata of staff together in a dynamic, united effort. Thus the institution's statement of mission will not be an abstract recitation of pieties but a living reality, a philosophy that is "owned" by the workers.

The Influence of Youth Music Television Viewership on Changes in Cigarette Use and Association with Smoking Peers: A Social Identity, Reinforcing Spirals Perspective.

PubMed

Slater, Michael D; Hayes, Andrew F

2010-12-01

Prior research has found strong evidence of a prospective association between R movie exposure and teen smoking. Using parallel process latent-growth modeling, the present study examines prospective associations between viewing of music video channels on television (e.g., MTV and VH-1) and changes over time in smoking and association with smoking peers. Results showed that baseline viewing of music-oriented channels such as MTV and VH-1 robustly predicted increasing trajectories of smoking and of associating with smoking peers, even after application of a variety of controls including parent reports of monitoring behavior. These results are consistent with the arguments from the reinforcing spirals model that such media use serves as a means of developing emergent adolescent social identities consistent with associating with smoking peers and acquiring smoking and other risk behaviors; evidence also suggests that media choice in reinforcing spiral processes are dynamic and evolve as social identity evolves.

2. View of switchback as it emerges to left of ...

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

2. View of switchback as it emerges to left of photograph. Skunk Harbor Road leaves the railroad grade at this point, looking southwest. 2400' from beginning of road 15N67. - Slaughterhouse Canyon Railroad Grade, South of State Highway 28 on East shore of Lake Tahoe, Carson City, Carson City, NV

3. VIEW LOOKING NORTH, COMPONENTS TEST LABORATORY, DYNAMIC TEST FACILITY ...

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

3. VIEW LOOKING NORTH, COMPONENTS TEST LABORATORY, DYNAMIC TEST FACILITY (SATURN V IN BACKGROUND). - Marshall Space Flight Center, East Test Area, Components Test Laboratory, Huntsville, Madison County, AL

The emergence of hydrogeophysics for improved understanding of subsurface processes over multiple scales

DOE PAGES

Binley, Andrew; Hubbard, Susan S.; Huisman, Johan A.; ...

2015-06-15

Geophysics provides a multidimensional suite of investigative methods that are transforming our ability to see into the very fabric of the subsurface environment, and monitor the dynamics of its fluids and the biogeochemical reactions that occur within it. Here we document how geophysical methods have emerged as valuable tools for investigating shallow subsurface processes over the past two decades and offer a vision for future developments relevant to hydrology and also ecosystem science. The field of “hydrogeophysics” arose in the late 1990s, prompted, in part, by the wealth of studies on stochastic subsurface hydrology that argued for better field-based investigativemore » techniques. These new hydrogeophysical approaches benefited from the emergence of practical and robust data inversion techniques, in many cases with a view to quantify shallow subsurface heterogeneity and the associated dynamics of subsurface fluids. Furthermore, the need for quantitative characterization stimulated a wealth of new investigations into petrophysical relationships that link hydrologically relevant properties to measurable geophysical parameters. Development of time-lapse approaches provided a new suite of tools for hydrological investigation, enhanced further with the realization that some geophysical properties may be sensitive to biogeochemical transformations in the subsurface environment, thus opening up the new field of “biogeophysics.” Early hydrogeophysical studies often concentrated on relatively small “plot-scale” experiments. More recently, however, the translation to larger-scale characterization has been the focus of a number of studies. In conclusion, geophysical technologies continue to develop, driven, in part, by the increasing need to understand and quantify key processes controlling sustainable water resources and ecosystem services.« less

The emergence of hydrogeophysics for improved understanding of subsurface processes over multiple scales

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

Binley, Andrew; Hubbard, Susan S.; Huisman, Johan A.

Geophysics provides a multidimensional suite of investigative methods that are transforming our ability to see into the very fabric of the subsurface environment, and monitor the dynamics of its fluids and the biogeochemical reactions that occur within it. Here we document how geophysical methods have emerged as valuable tools for investigating shallow subsurface processes over the past two decades and offer a vision for future developments relevant to hydrology and also ecosystem science. The field of “hydrogeophysics” arose in the late 1990s, prompted, in part, by the wealth of studies on stochastic subsurface hydrology that argued for better field-based investigativemore » techniques. These new hydrogeophysical approaches benefited from the emergence of practical and robust data inversion techniques, in many cases with a view to quantify shallow subsurface heterogeneity and the associated dynamics of subsurface fluids. Furthermore, the need for quantitative characterization stimulated a wealth of new investigations into petrophysical relationships that link hydrologically relevant properties to measurable geophysical parameters. Development of time-lapse approaches provided a new suite of tools for hydrological investigation, enhanced further with the realization that some geophysical properties may be sensitive to biogeochemical transformations in the subsurface environment, thus opening up the new field of “biogeophysics.” Early hydrogeophysical studies often concentrated on relatively small “plot-scale” experiments. More recently, however, the translation to larger-scale characterization has been the focus of a number of studies. In conclusion, geophysical technologies continue to develop, driven, in part, by the increasing need to understand and quantify key processes controlling sustainable water resources and ecosystem services.« less

The emergence of hydrogeophysics for improved understanding of subsurface processes over multiple scales

PubMed Central

Hubbard, Susan S.; Huisman, Johan A.; Revil, André; Robinson, David A.; Singha, Kamini; Slater, Lee D.

2015-01-01

Abstract Geophysics provides a multidimensional suite of investigative methods that are transforming our ability to see into the very fabric of the subsurface environment, and monitor the dynamics of its fluids and the biogeochemical reactions that occur within it. Here we document how geophysical methods have emerged as valuable tools for investigating shallow subsurface processes over the past two decades and offer a vision for future developments relevant to hydrology and also ecosystem science. The field of “hydrogeophysics” arose in the late 1990s, prompted, in part, by the wealth of studies on stochastic subsurface hydrology that argued for better field‐based investigative techniques. These new hydrogeophysical approaches benefited from the emergence of practical and robust data inversion techniques, in many cases with a view to quantify shallow subsurface heterogeneity and the associated dynamics of subsurface fluids. Furthermore, the need for quantitative characterization stimulated a wealth of new investigations into petrophysical relationships that link hydrologically relevant properties to measurable geophysical parameters. Development of time‐lapse approaches provided a new suite of tools for hydrological investigation, enhanced further with the realization that some geophysical properties may be sensitive to biogeochemical transformations in the subsurface environment, thus opening up the new field of “biogeophysics.” Early hydrogeophysical studies often concentrated on relatively small “plot‐scale” experiments. More recently, however, the translation to larger‐scale characterization has been the focus of a number of studies. Geophysical technologies continue to develop, driven, in part, by the increasing need to understand and quantify key processes controlling sustainable water resources and ecosystem services. PMID:26900183

The Value of Friction, Tension, and Disparity in Global Collaboration (Invited)

NASA Astrophysics Data System (ADS)

Parsons, M. A.

2013-12-01

Misunderstandings; conflicting goals; competition for limited funds; differing worldviews, agendas, ideals... These types of 'friction' are inevitable in national and global collaboration. And while friction can create tension and conflict, it is not inherently bad. It is at these points of interaction and tension where we can sometimes gain the most insight. Common understanding comes not only through agreed universal principles but also through multiple lines of evidence that wind through disparate views and describe a greater story. Collaboration is not straightforward in an environment of friction, tension, and disparity. Collaborators do not necessarily have common goals. Dynamic, coalition-style politics emerge. How can we align these disparities to achieve standards and common knowledge while still valuing and understanding differing perspectives? Achieving the understanding that comes through both unity and disparity is a central goal of the Research Data Alliance. RDA is emerging as a "neutral place" or "social gateway" where frictions can be identified, addressed, and understood but not necessarily removed.

Structural Inheritance of the Actin Cytoskeletal Organization Determines the Body Axis in Regenerating Hydra.

PubMed

Livshits, Anton; Shani-Zerbib, Lital; Maroudas-Sacks, Yonit; Braun, Erez; Keren, Kinneret

2017-02-07

Understanding how mechanics complement bio-signaling in defining patterns during morphogenesis is an outstanding challenge. Here, we utilize the multicellular polyp Hydra to investigate the role of the actomyosin cytoskeleton in morphogenesis. We find that the supra-cellular actin fiber organization is inherited from the parent Hydra and determines the body axis in regenerating tissue segments. This form of structural inheritance is non-trivial because of the tissue folding and dynamic actin reorganization involved. We further show that the emergence of multiple body axes can be traced to discrepancies in actin fiber alignment at early stages of the regeneration process. Mechanical constraints induced by anchoring regenerating Hydra on stiff wires suppressed the emergence of multiple body axes, highlighting the importance of mechanical feedbacks in defining and stabilizing the body axis. Together, these results constitute an important step toward the development of an integrated view of morphogenesis that incorporates mechanics. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Evolution of the environmental justice movement: activism, formalization and differentiation

NASA Astrophysics Data System (ADS)

Colsa Perez, Alejandro; Grafton, Bernadette; Mohai, Paul; Hardin, Rebecca; Hintzen, Katy; Orvis, Sara

2015-10-01

To complement a recent flush of research on transnational environmental justice movements, we sought a deeper organizational history of what we understand as the contemporary environmental justice movement in the United States. We thus conducted in-depth interviews with 31 prominent environmental justice activists, scholars, and community leaders across the US. Today’s environmental justice groups have transitioned from specific local efforts to broader national and global mandates, and more sophisticated political, technological, and activist strategies. One of the most significant transformations has been the number of groups adopting formal legal status, and emerging as registered environmental justice organizations (REJOs) within complex partnerships. This article focuses on the emergence of REJOs, and describes the respondents’ views about the implications of this for more local grassroots groups. It reveals a central irony animating work across groups in today’s movement: legal formalization of many environmental justice organizations has made the movement increasingly internally differentiated, dynamic, and networked, even as the passage of actual national laws on environmental justice has proven elusive.

Neural Population Dynamics during Reaching Are Better Explained by a Dynamical System than Representational Tuning

PubMed Central

Dann, Benjamin

2016-01-01

Recent models of movement generation in motor cortex have sought to explain neural activity not as a function of movement parameters, known as representational models, but as a dynamical system acting at the level of the population. Despite evidence supporting this framework, the evaluation of representational models and their integration with dynamical systems is incomplete in the literature. Using a representational velocity-tuning based simulation of center-out reaching, we show that incorporating variable latency offsets between neural activity and kinematics is sufficient to generate rotational dynamics at the level of neural populations, a phenomenon observed in motor cortex. However, we developed a covariance-matched permutation test (CMPT) that reassigns neural data between task conditions independently for each neuron while maintaining overall neuron-to-neuron relationships, revealing that rotations based on the representational model did not uniquely depend on the underlying condition structure. In contrast, rotations based on either a dynamical model or motor cortex data depend on this relationship, providing evidence that the dynamical model more readily explains motor cortex activity. Importantly, implementing a recurrent neural network we demonstrate that both representational tuning properties and rotational dynamics emerge, providing evidence that a dynamical system can reproduce previous findings of representational tuning. Finally, using motor cortex data in combination with the CMPT, we show that results based on small numbers of neurons or conditions should be interpreted cautiously, potentially informing future experimental design. Together, our findings reinforce the view that representational models lack the explanatory power to describe complex aspects of single neuron and population level activity. PMID:27814352

Neural Population Dynamics during Reaching Are Better Explained by a Dynamical System than Representational Tuning.

PubMed

Michaels, Jonathan A; Dann, Benjamin; Scherberger, Hansjörg

2016-11-01

Recent models of movement generation in motor cortex have sought to explain neural activity not as a function of movement parameters, known as representational models, but as a dynamical system acting at the level of the population. Despite evidence supporting this framework, the evaluation of representational models and their integration with dynamical systems is incomplete in the literature. Using a representational velocity-tuning based simulation of center-out reaching, we show that incorporating variable latency offsets between neural activity and kinematics is sufficient to generate rotational dynamics at the level of neural populations, a phenomenon observed in motor cortex. However, we developed a covariance-matched permutation test (CMPT) that reassigns neural data between task conditions independently for each neuron while maintaining overall neuron-to-neuron relationships, revealing that rotations based on the representational model did not uniquely depend on the underlying condition structure. In contrast, rotations based on either a dynamical model or motor cortex data depend on this relationship, providing evidence that the dynamical model more readily explains motor cortex activity. Importantly, implementing a recurrent neural network we demonstrate that both representational tuning properties and rotational dynamics emerge, providing evidence that a dynamical system can reproduce previous findings of representational tuning. Finally, using motor cortex data in combination with the CMPT, we show that results based on small numbers of neurons or conditions should be interpreted cautiously, potentially informing future experimental design. Together, our findings reinforce the view that representational models lack the explanatory power to describe complex aspects of single neuron and population level activity.

Resetting the Clock: The Dynamics of Organizational Change and Failure.

ERIC Educational Resources Information Center

Amburgey, Terry L.; And Others

1993-01-01

When viewed dynamically, organizational change can be both adaptive and disruptive. When viewed over time, same forces rendering organizations inert also make them more malleable. These ideas are supported by dynamic models of organizational failure and change estimated on population of 1,011 Finnish newspaper organizations over 193 years. Change…

Nonlinear Synergistic Emergence and Predictability in Complex Systems: Theory and Hydro-Climatic Applications

NASA Astrophysics Data System (ADS)

Perdigão, Rui A. P.; Hall, Julia; Pires, Carlos A. L.; Blöschl, Günter

2017-04-01

Classical and stochastic dynamical system theories assume structural coherence and dynamic recurrence with invariants of motion that are not necessarily so. These are grounded on the unproven assumption of universality in the dynamic laws derived from statistical kinematic evaluation of non-representative empirical records. As a consequence, the associated formulations revolve around a restrictive set of configurations and intermittencies e.g. in an ergodic setting, beyond which any predictability is essentially elusive. Moreover, dynamical systems are fundamentally framed around dynamic codependence among intervening processes, i.e. entail essentially redundant interactions such as couplings and feedbacks. That precludes synergistic cooperation among processes that, whilst independent from each other, jointly produce emerging dynamic behaviour not present in any of the intervening parties. In order to overcome these fundamental limitations, we introduce a broad class of non-recursive dynamical systems that formulate dynamic emergence of unprecedented states in a fundamental synergistic manner, with fundamental principles in mind. The overall theory enables innovations to be predicted from the internal system dynamics before any a priori information is provided about the associated dynamical properties. The theory is then illustrated to anticipate, from non-emergent records, the spatiotemporal emergence of multiscale hyper chaotic regimes, critical transitions and structural coevolutionary changes in synthetic and real-world complex systems. Example applications are provided within the hydro-climatic context, formulating and dynamically forecasting evolving hydro-climatic distributions, including the emergence of extreme precipitation and flooding in a structurally changing hydro-climate system. Validation is then conducted with a posteriori verification of the simulated dynamics against observational records. Agreement between simulations and observations is confirmed with robust nonlinear information diagnostics.

VIEW OF EMERGENCY RESPONSE VEHICLES PARKED OUTSIDE BUILDING 331, THE ...

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

VIEW OF EMERGENCY RESPONSE VEHICLES PARKED OUTSIDE BUILDING 331, THE VEHICLE MAINTENANCE GARAGE AND FIRE STATION. THE BUILDING, ORIGINALLY CONSTRUCTED IN 1953, WAS DESIGNED AND UTILIZED AS A WAREHOUSE. ADDITIONS TO THE STRUCTURE, INCLUDING THE FIRE DEPARTMENT STRUCTURE, WERE COMPLETED IN 1967. (4/7/87) - Rocky Flats Plant, Vehicle Maintenance Garage & Fire Station, Golden, Jefferson County, CO

Floral Morphogenesis: Stochastic Explorations of a Gene Network Epigenetic Landscape

PubMed Central

Aldana, Maximino; Benítez, Mariana; Cortes-Poza, Yuriria; Espinosa-Soto, Carlos; Hartasánchez, Diego A.; Lotto, R. Beau; Malkin, David; Escalera Santos, Gerardo J.; Padilla-Longoria, Pablo

2008-01-01

In contrast to the classical view of development as a preprogrammed and deterministic process, recent studies have demonstrated that stochastic perturbations of highly non-linear systems may underlie the emergence and stability of biological patterns. Herein, we address the question of whether noise contributes to the generation of the stereotypical temporal pattern in gene expression during flower development. We modeled the regulatory network of organ identity genes in the Arabidopsis thaliana flower as a stochastic system. This network has previously been shown to converge to ten fixed-point attractors, each with gene expression arrays that characterize inflorescence cells and primordial cells of sepals, petals, stamens, and carpels. The network used is binary, and the logical rules that govern its dynamics are grounded in experimental evidence. We introduced different levels of uncertainty in the updating rules of the network. Interestingly, for a level of noise of around 0.5–10%, the system exhibited a sequence of transitions among attractors that mimics the sequence of gene activation configurations observed in real flowers. We also implemented the gene regulatory network as a continuous system using the Glass model of differential equations, that can be considered as a first approximation of kinetic-reaction equations, but which are not necessarily equivalent to the Boolean model. Interestingly, the Glass dynamics recover a temporal sequence of attractors, that is qualitatively similar, although not identical, to that obtained using the Boolean model. Thus, time ordering in the emergence of cell-fate patterns is not an artifact of synchronous updating in the Boolean model. Therefore, our model provides a novel explanation for the emergence and robustness of the ubiquitous temporal pattern of floral organ specification. It also constitutes a new approach to understanding morphogenesis, providing predictions on the population dynamics of cells with different genetic configurations during development. PMID:18978941

Multivariate pattern analysis of MEG and EEG: A comparison of representational structure in time and space.

PubMed

Cichy, Radoslaw Martin; Pantazis, Dimitrios

2017-09-01

Multivariate pattern analysis of magnetoencephalography (MEG) and electroencephalography (EEG) data can reveal the rapid neural dynamics underlying cognition. However, MEG and EEG have systematic differences in sampling neural activity. This poses the question to which degree such measurement differences consistently bias the results of multivariate analysis applied to MEG and EEG activation patterns. To investigate, we conducted a concurrent MEG/EEG study while participants viewed images of everyday objects. We applied multivariate classification analyses to MEG and EEG data, and compared the resulting time courses to each other, and to fMRI data for an independent evaluation in space. We found that both MEG and EEG revealed the millisecond spatio-temporal dynamics of visual processing with largely equivalent results. Beyond yielding convergent results, we found that MEG and EEG also captured partly unique aspects of visual representations. Those unique components emerged earlier in time for MEG than for EEG. Identifying the sources of those unique components with fMRI, we found the locus for both MEG and EEG in high-level visual cortex, and in addition for MEG in low-level visual cortex. Together, our results show that multivariate analyses of MEG and EEG data offer a convergent and complimentary view on neural processing, and motivate the wider adoption of these methods in both MEG and EEG research. Copyright © 2017 Elsevier Inc. All rights reserved.

Depth interval estimates from motion parallax and binocular disparity beyond interaction space.

PubMed

Gillam, Barbara; Palmisano, Stephen A; Govan, Donovan G

2011-01-01

Static and dynamic observers provided binocular and monocular estimates of the depths between real objects lying well beyond interaction space. On each trial, pairs of LEDs were presented inside a dark railway tunnel. The nearest LED was always 40 m from the observer, with the depth separation between LED pairs ranging from 0 up to 248 m. Dynamic binocular viewing was found to produce the greatest (ie most veridical) estimates of depth magnitude, followed next by static binocular viewing, and then by dynamic monocular viewing. (No significant depth was seen with static monocular viewing.) We found evidence that both binocular and monocular dynamic estimates of depth were scaled for the observation distance when the ground plane and walls of the tunnel were visible up to the nearest LED. We conclude that both motion parallax and stereopsis provide useful long-distance depth information and that motion-parallax information can enhance the degree of stereoscopic depth seen.

Spatiotemporal periodicity of dislocation dynamics in a two-dimensional microfluidic crystal flowing in a tapered channel

DOE PAGES

Gai, Ya; Min Leong, Chia; Cai, Wei; ...

2016-10-10

When a many-body system is driven away from equilibrium, order can spontaneously emerge in places where disorder might be expected. Here we report an unexpected order in the flow of a concentrated emulsion in a tapered microfluidic channel. The velocity profiles of individual drops in the emulsion show periodic patterns in both space and time. Such periodic patterns appear surprising from both a fluid and a solid mechanics point of view. In particular, when the emulsion is considered as a soft crystal under extrusion, a disordered scenario might be expected based on the stochastic nature of dislocation dynamics in microscopicmore » crystals. However, an orchestrated sequence of dislocation nucleation and migration is observed to give rise to a highly ordered deformation mode. This discovery suggests that nanocrystals can be made to deform more controllably than previously thought. It can also lead to novel flow control and mixing strategies in droplet microfluidics.« less

Clustered marginalization of minorities during social transitions induced by co-evolution of behaviour and network structure

NASA Astrophysics Data System (ADS)

Schleussner, Carl-Friedrich; Donges, Jonathan F.; Engemann, Denis A.; Levermann, Anders

2016-08-01

Large-scale transitions in societies are associated with both individual behavioural change and restructuring of the social network. These two factors have often been considered independently, yet recent advances in social network research challenge this view. Here we show that common features of societal marginalization and clustering emerge naturally during transitions in a co-evolutionary adaptive network model. This is achieved by explicitly considering the interplay between individual interaction and a dynamic network structure in behavioural selection. We exemplify this mechanism by simulating how smoking behaviour and the network structure get reconfigured by changing social norms. Our results are consistent with empirical findings: The prevalence of smoking was reduced, remaining smokers were preferentially connected among each other and formed increasingly marginalized clusters. We propose that self-amplifying feedbacks between individual behaviour and dynamic restructuring of the network are main drivers of the transition. This generative mechanism for co-evolution of individual behaviour and social network structure may apply to a wide range of examples beyond smoking.

Dynamics of problem setting and framing in citizen discussions on synthetic biology

PubMed Central

Betten, Afke Wieke; Broerse, Jacqueline E.W.; Kupper, Frank

2017-01-01

Synthetic biology is an emerging scientific field where engineers and biologists design and build biological systems for various applications. Developing synthetic biology responsibly in the public interest necessitates a meaningful societal dialogue. In this article, we argue that facilitating such a dialogue requires an understanding of how people make sense of synthetic biology. We performed qualitative research to unravel the underlying dynamics of problem setting and framing in citizen discussions on synthetic biology. We found that most people are not inherently for or against synthetic biology as a technology or development in itself, but that their perspectives are framed by core values about our relationships with science and technology and that sensemaking is much dependent on the context and general feelings of (dis)content. Given that there are many assumptions focused on a more binary idea of the public’s view, we emphasize the need for frame awareness and understanding in a meaningful dialogue. PMID:28597721

Clustered marginalization of minorities during social transitions induced by co-evolution of behaviour and network structure.

PubMed

Schleussner, Carl-Friedrich; Donges, Jonathan F; Engemann, Denis A; Levermann, Anders

2016-08-11

Large-scale transitions in societies are associated with both individual behavioural change and restructuring of the social network. These two factors have often been considered independently, yet recent advances in social network research challenge this view. Here we show that common features of societal marginalization and clustering emerge naturally during transitions in a co-evolutionary adaptive network model. This is achieved by explicitly considering the interplay between individual interaction and a dynamic network structure in behavioural selection. We exemplify this mechanism by simulating how smoking behaviour and the network structure get reconfigured by changing social norms. Our results are consistent with empirical findings: The prevalence of smoking was reduced, remaining smokers were preferentially connected among each other and formed increasingly marginalized clusters. We propose that self-amplifying feedbacks between individual behaviour and dynamic restructuring of the network are main drivers of the transition. This generative mechanism for co-evolution of individual behaviour and social network structure may apply to a wide range of examples beyond smoking.

Dynamical resource nexus assessments: from accounting to sustainability approaches

NASA Astrophysics Data System (ADS)

Salmoral, Gloria; Yan, Xiaoyu

2017-04-01

Continued economic development and population growth result in increasing pressures on natural resources, from local to international levels, for meeting societal demands on water, energy and food. To date there are a few tools that link models to identify the relationships and to account for flows of water, energy and food. However, these tools in general can offer only a static view often at national level and with annual temporal resolution. Moreover, they can only account flows but cannot consider the required amounts and conditions of the natural capital that supplies and maintains these flows. With the emerging nexus thinking, our research is currently focused on promoting dynamical environmental analyses beyond the conventional silo mentalities. Our study aims to show new advancements in existing tools (e.g., dynamical life cycle assessment) and develop novel environmental indicators relevant for the resource nexus assessment. We aim to provide a step forward when sustainability conditions and resilience thresholds are aligned with flows under production (e.g., food, water and energy), process level under analysis (e.g., local production, transport, manufacturing, final consumption, reuse, disposal) and existing biophysical local conditions. This approach would help to embrace and better characterise the spatiotemporal dynamics, complexity and existing links between and within the natural and societal systems, which are crucial to evaluate and promote more environmentally sustainable economic activities.

The Interface of Environmental and Humane Education as an Emerging and Relevant Dialogue: A Point of View from Brazil

ERIC Educational Resources Information Center

Castellano, Maria; Quirino de Luca, Andrea; Sorrentino, Marcos

2011-01-01

This article addresses the interface between environmental and humane education, as a theoretical and practical emerging field in Brazil. We begin by presenting conceptual similarities that, in our view, underpin and justify the need for a growing connection between the two fields of research and educational practice. We then describe an…

33 CFR 337.7 - Emergency actions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... measures to modify the emergency operation to reduce, avoid, or minimize adverse environmental impacts. If... DEFENSE PRACTICE AND PROCEDURE § 337.7 Emergency actions. After obtaining approval from the division..., as necessary, an environmental assessment, if this is practicable in view of the emergency situation...

33 CFR 337.7 - Emergency actions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... measures to modify the emergency operation to reduce, avoid, or minimize adverse environmental impacts. If... DEFENSE PRACTICE AND PROCEDURE § 337.7 Emergency actions. After obtaining approval from the division..., as necessary, an environmental assessment, if this is practicable in view of the emergency situation...

33 CFR 337.7 - Emergency actions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... measures to modify the emergency operation to reduce, avoid, or minimize adverse environmental impacts. If... DEFENSE PRACTICE AND PROCEDURE § 337.7 Emergency actions. After obtaining approval from the division..., as necessary, an environmental assessment, if this is practicable in view of the emergency situation...

33 CFR 337.7 - Emergency actions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... measures to modify the emergency operation to reduce, avoid, or minimize adverse environmental impacts. If... DEFENSE PRACTICE AND PROCEDURE § 337.7 Emergency actions. After obtaining approval from the division..., as necessary, an environmental assessment, if this is practicable in view of the emergency situation...

Exploring the value of technology to stimulate interprofessional discussion and education: a needs assessment of emergency medicine professionals.

PubMed

Riley, Jennifer; McGowan, Melissa; Rozmovits, Linda

2014-06-30

The emergency department (ED) is an environment fraught with increasing patient volumes, competing priorities, fluctuating information, and ad hoc interprofessional clinical teams. Limited time is available to reflect on and discuss clinical experiences, policies, or research with others on the involved team. Online resources, such as webcasts and blogs, offer an accessible platform for emergency shift workers to engage in interprofessional discussion and education. Our objective was to explore the current opportunities for shared learning and discussion and to discover the potential of online resources to foster and facilitate interprofessional education within an academic tertiary emergency department community. A qualitative study using semistructured interviews was conducted to solicit participants' views of the current culture of IPE in the ED, the potential value of introducing new online resources and technology in support of IPE, and possible barriers to uptake. Participation was voluntary and participants provided verbal informed consent. Online resources discussed included webcasts, interactive discussion forums, websites, and dashboard with links to central repositories. Identified barriers to uptake of new online resources were an unwillingness to "work" off-shift, a dislike of static one-directional communication, concerns with confidentiality, and the suggestion that new resources would be used by only a select few. Owing to the sensitive dynamics of emergency medicine-and the preference among its professional staff to foster interprofessional discussion and education through personal engagement, in an unhurried, non-stressful environment-introducing and investing in online resources should be undertaken with caution.

Emergency material allocation with time-varying supply-demand based on dynamic optimization method for river chemical spills.

PubMed

Liu, Jie; Guo, Liang; Jiang, Jiping; Jiang, Dexun; Wang, Peng

2018-04-13

Aiming to minimize the damage caused by river chemical spills, efficient emergency material allocation is critical for an actual emergency rescue decision-making in a quick response. In this study, an emergency material allocation framework based on time-varying supply-demand constraint is developed to allocate emergency material, minimize the emergency response time, and satisfy the dynamic emergency material requirements in post-accident phases dealing with river chemical spills. In this study, the theoretically critical emergency response time is firstly obtained for the emergency material allocation system to select a series of appropriate emergency material warehouses as potential supportive centers. Then, an enumeration method is applied to identify the practically critical emergency response time, the optimum emergency material allocation and replenishment scheme. Finally, the developed framework is applied to a computational experiment based on south-to-north water transfer project in China. The results illustrate that the proposed methodology is a simple and flexible tool for appropriately allocating emergency material to satisfy time-dynamic demands during emergency decision-making. Therefore, the decision-makers can identify an appropriate emergency material allocation scheme in a balance between time-effective and cost-effective objectives under the different emergency pollution conditions.

Consumer opinions of emergency room medical care.

PubMed

McMillan, J R; Younger, M S; DeWine, L C

1984-12-01

If hospital management is to adapt successfully to an increasingly competitive environment, and to retain a viable emergency department, it well be necessary to objectively and accurately assess the hospital's image in the community served. Knowledge of the consumers' views is an essential input into the formulation of strategic plans. This article reports on a study in which consumer opinions on 15 dimensions of emergency room health care were obtained from 723 respondents using a mail questionnaire. Findings reveal that consumers view the emergency room as being more expensive than other health care providers. Except for being available or convenient, little or no advantage is perceived for the emergency room over the personal physician. Even though the emergency room has specialized staff and equipment, consumers do not believe patients receive better or faster treatment in an emergency room than would be obtained in a physician's office. Unless changed, these perceptions will diminish the role of the emergency room in the delivery of health care services.

Birth of an abstraction: a dynamical systems account of the discovery of an elsewhere principle in a category learning task.

PubMed

Tabor, Whitney; Cho, Pyeong W; Dankowicz, Harry

2013-01-01

Human participants and recurrent ("connectionist") neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular ("strong") classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the Elsewhere Condition (Kiparsky, 1973). Previous connectionist accounts of related phenomena have often been vague about the nature of the networks' encoding systems. We analyzed our network using dynamical systems theory, revealing topological and geometric properties that can be directly compared with the mechanisms of non-connectionist, rule-based accounts. The results reveal that the networks "contain" structures related to mechanisms posited by rule-based models, partly vindicating the insights of these models. On the other hand, they support the one mechanism (OM), as opposed to the more than one mechanism (MOM), view of symbolic abstraction by showing how the appearance of MOM behavior can arise emergently from one underlying set of principles. The key new contribution of this study is to show that dynamical systems theory can allow us to explicitly characterize the relationship between the two perspectives in implemented models. © 2013 Cognitive Science Society, Inc.

Discoveries about Tropospheric Ozone Pollution from Satellite and Soundings

NASA Technical Reports Server (NTRS)

Thompson, Anne M.

2004-01-01

We have been producing near-red time tropospheric ozone satellite maps from the TOMS (Total Ozone Mapping Spectrometer) sensor since 1997. Maps for 1996-2000 for the operational Earth-Probe instrument are at:. Pollution in the tropics is influenced by biomass burning and by transport patterns that favor recirculation and in other cases reflect climate variability like the El-Nino-Southern Oscillation [Thompson et al., 2001]. The satellite view of chemical-dynamical interactions in tropospheric ozone is not adequate to capture vertical gradients in pollution. Thus, in 1998, NASA's Goddard Space Flight Center and a team of international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap in tropical ozone soundings. SHADOZ augments launches and provides a public archive of ozonesonde data from twelve tropical stations at http://croc.gsfc.nasa.gov/shadoz. Further insights into the role of chemical and dynamical influences have emerged from the first 4-5 years of SHADOZ data (more than 2000 ozone profiles). Highly variable tropospheric ozone and a zonal wave-one pattern in tropospheric ozone suggest that dynamics is as important as pollution in determining tropical ozone distributions.

The role of ecological dynamics in analysing performance in team sports.

PubMed

Vilar, Luís; Araújo, Duarte; Davids, Keith; Button, Chris

2012-01-01

Performance analysis is a subdiscipline of sports sciences and one-approach, notational analysis, has been used to objectively audit and describe behaviours of performers during different subphases of play, providing additional information for practitioners to improve future sports performance. Recent criticisms of these methods have suggested the need for a sound theoretical rationale to explain performance behaviours, not just describe them. The aim of this article was to show how ecological dynamics provides a valid theoretical explanation of performance in team sports by explaining the formation of successful and unsuccessful patterns of play, based on symmetry-breaking processes emerging from functional interactions between players and the performance environment. We offer the view that ecological dynamics is an upgrade to more operational methods of performance analysis that merely document statistics of competitive performance. In support of our arguments, we refer to exemplar data on competitive performance in team sports that have revealed functional interpersonal interactions between attackers and defenders, based on variations in the spatial positioning of performers relative to each other in critical performance areas, such as the scoring zones. Implications of this perspective are also considered for practice task design and sport development programmes.

Group marking and peer assessment during a group poster presentation: the experiences and views of midwifery students.

PubMed

Ohaja, Magdalena; Dunlea, Margaret; Muldoon, Kathryn

2013-09-01

Traditionally, written examination and clinical practice assessments are the main ways of deeming midwifery students fit and competent for practice. Contemporary academics in an effort to engage the students in the learning process have employed alternative teaching and assessment strategies. Among the alternative strategies are group projects after which members of the group are awarded the same grade, and peer assessment. With the purpose of informing the midwifery curricular, we utilised a qualitative descriptive approach to explore midwifery students' experiences and views on the use of group poster presentation for learning and assessment. The participants consisted of a purposive sample of 14 higher diploma midwifery students who were registered in a third level institution in Ireland. Semi-structured individual interviews were conducted following the completion of the poster presentation assessment. Permission to undertake the study was obtained from the college ethics committee. In this paper, we focus on the participants' views of group marking and peer assessment which are among the key elements that emerged in this study. While awarding a group mark was overall accepted, peer assessment proved a more contentious issue. Most of the participants found it challenging marking their friends. Reactions to group marks were very much influenced by the group dynamics. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ultradian metronome: timekeeper for orchestration of cellular coherence.

PubMed

Lloyd, David; Murray, Douglas B

2005-07-01

Dynamic intracellular spatial and temporal organization emerges from spontaneous synchronization of a massive array of weakly coupled oscillators; the majority of subcellular processes are implicated in this integrated expression of cellular physiology. Evidence for this view comes mainly from studies of Saccharomyces cerevisiae growing in self-synchronized continuous cultures, in which a temperature-compensated ultradian clock (period of approximately 40 min) couples fermentation with redox state in addition to the transcriptome and cell-division-cycle progression. Functions for ultradian clocks have also been determined in other yeasts (e.g. Schizosaccharomyces pombe and Candida utilis), seven protists (e.g. Acanthamoeba castellanii and Paramecium tetraurelia), as well as cultured mammalian cells. We suggest that ultradian timekeeping is a basic universal necessity for coordinated intracellular coherence.

Sunspots

NASA Technical Reports Server (NTRS)

Moore, R.; Rabin, D.

1985-01-01

It is pointed out that the sun provides a close-up view of many astrophysically important phenomena, nearly all connected with the causes and effects of solar magnetic fields. The present article provides a review of the role of sunspots in a number of new areas of research. Connections with other solar phenomena are examined, taking into account flares, the solar magnetic cycle, global flows, luminosity variation, and global oscillations. A selective review of the structure and dynamic phenomena observed within sunspots is also presented. It is found that sunspots are usually contorted during the growth phase of an active region as magnetic field rapidly emerges and sunspots form, coalesce, and move past or even through each other. Attention is given to structure and flows, oscillations and waves, and plans for future studies.

Comment on "Relating side chain organization of PNIPAm with its conformation in aqueous methanol" by D. Mukherji, M. Wagner, M. D. Watson, S. Winzen, T. E. de Oliveira, C. M. Marques and K. Kremer, Soft Matter, 2016, 12, 7995.

PubMed

van der Vegt, Nico F A; Rodríguez-Ropero, Francisco

2017-03-22

In a recent paper, Mukherji et al. describe the collapse of poly(N-isopropyl acrylamide) in methanol-water mixtures based on experiments and molecular dynamics simulations. The conclusion of their work is that chain collapse is dominated by enthalpic bridging interactions while entropic effects play no major role. Here we show that this claim arises from an improper interpretation of preferential binding and the corresponding thermodynamic data presented. When interpreted correctly, the data instead provide evidence for repulsive enthalpic interactions of methanol with the polymer, supporting the emerging view of entropic chain collapse.

Respectful Modeling: Addressing Uncertainty in Dynamic System Models for Molecular Biology.

PubMed

Tsigkinopoulou, Areti; Baker, Syed Murtuza; Breitling, Rainer

2017-06-01

Although there is still some skepticism in the biological community regarding the value and significance of quantitative computational modeling, important steps are continually being taken to enhance its accessibility and predictive power. We view these developments as essential components of an emerging 'respectful modeling' framework which has two key aims: (i) respecting the models themselves and facilitating the reproduction and update of modeling results by other scientists, and (ii) respecting the predictions of the models and rigorously quantifying the confidence associated with the modeling results. This respectful attitude will guide the design of higher-quality models and facilitate the use of models in modern applications such as engineering and manipulating microbial metabolism by synthetic biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Volatile accretion history of the terrestrial planets and dynamic implications.

PubMed

Albarède, Francis

2009-10-29

Accretion left the terrestrial planets depleted in volatile components. Here I examine evidence for the hypothesis that the Moon and the Earth were essentially dry immediately after the formation of the Moon-by a giant impact on the proto-Earth-and only much later gained volatiles through accretion of wet material delivered from beyond the asteroid belt. This view is supported by U-Pb and I-Xe chronologies, which show that water delivery peaked approximately 100 million years after the isolation of the Solar System. Introduction of water into the terrestrial mantle triggered plate tectonics, which may have been crucial for the emergence of life. This mechanism may also have worked for the young Venus, but seems to have failed for Mars.

ROS in Cancer: The Burning Question

PubMed Central

2017-01-01

Summary An unanswered question in human health is whether anti-oxidation prevents or promotes cancer. Anti-oxidation has historically been viewed as chemo-preventive but emerging evidence suggests that antioxidants may be supportive of neoplasia. We posit this contention to be rooted in the fact that ROS do not operate as one single biochemical entity, but as diverse secondary messengers in cancer cells. This cautions against therapeutic strategies to increase ROS at a global level. To leverage redox alterations towards the development of effective therapies necessitates the application of biophysical and biochemical approaches to define redox dynamics and to functionally elucidate specific oxidative modifications in cancer versus normal cells. An improved understanding of the sophisticated workings of redox biology is imperative to defeating cancer. PMID:28427863

Universal ideal behavior and macroscopic work relation of linear irreversible stochastic thermodynamics

NASA Astrophysics Data System (ADS)

Ma, Yi-An; Qian, Hong

2015-06-01

We revisit the Ornstein-Uhlenbeck (OU) process as the fundamental mathematical description of linear irreversible phenomena, with fluctuations, near an equilibrium. By identifying the underlying circulating dynamics in a stationary process as the natural generalization of classical conservative mechanics, a bridge between a family of OU processes with equilibrium fluctuations and thermodynamics is established through the celebrated Helmholtz theorem. The Helmholtz theorem provides an emergent macroscopic ‘equation of state’ of the entire system, which exhibits a universal ideal thermodynamic behavior. Fluctuating macroscopic quantities are studied from the stochastic thermodynamic point of view and a non-equilibrium work relation is obtained in the macroscopic picture, which may facilitate experimental study and application of the equalities due to Jarzynski, Crooks, and Hatano and Sasa.

VIEW OF BUILDING 122 WHICH HOUSES THE ONSITE MEDICAL FACILITIES ...

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

VIEW OF BUILDING 122 WHICH HOUSES THE ON-SITE MEDICAL FACILITIES OF THE ROCKY FLATS PLANT AND THE OCCUPATIONAL HEALTH AND INTERNAL DOSIMETRY ORGANIZATIONS. EMERGENCY MEDICAL SERVICES, DIAGNOSIS, DECONTAMINATION, FIRST AID, X-RAY, MINOR SURGICAL TREATMENT, AND AMBULATORY ACTIVITIES ARE CARRIED OUT IN THIS BUILDING. (1/98) - Rocky Flats Plant, Emergency Medical Services Facility, Southwest corner of Central & Third Avenues, Golden, Jefferson County, CO

Evidence for the Early Emergence of the Simple View of Reading in a Transparent Orthography

ERIC Educational Resources Information Center

Kendeou, Panayiota; Papadopoulos, Timothy C.; Kotzapoulou, Marianna

2013-01-01

The main aim of the present study was to empirically test the emergence of the Simple View of Reading (SVR) in a transparent orthography, and specifically in Greek. To do so, we examined whether the constituent components of the SVR could be identified in young, Greek-speaking children even before the beginning of formal reading instruction. Our…

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.

Psychosocial care for seriously injured children and their families: a qualitative study among emergency department nurses and physicians.

PubMed

Alisic, Eva; Conroy, Rowena; Magyar, Joanne; Babl, Franz E; O'Donnell, Meaghan L

2014-09-01

Approximately one in five children who sustain a serious injury develops persistent stress symptoms. Emergency Department nurses and physicians have a pivotal role in psychosocial care for seriously injured children. However, little is known about staff's views on this role. Our aim was to investigate Emergency Department staff's views on psychosocial care for seriously injured children. We conducted semi-structured interviews with 20 nurses and physicians working in an Australian Paediatric Emergency Department. We used purposive sampling to obtain a variety of views. The interviews were transcribed verbatim and major themes were derived in line with the summative analysis method. We also mapped participants' strategies for child and family support on the eight principles of Psychological First Aid (PFA). Five overarching themes emerged: (1) staff find psychosocial issues important but focus on physical care; (2) staff are aware of individual differences but have contrasting views on vulnerability; (3) parents have a central role; (4) staff use a variety of psychosocial strategies to support children, based on instinct and experience but not training; and (5) staff have individually different wishes regarding staff- and self-care. Staff elaborated most on strategies related to the PFA elements 'contact and engagement', 'stabilization', 'connection with social supports' and least on 'informing about coping'. The strong notion of individual differences in views suggests a need for training in psychosocial care for injured children and their families. In addition, further research on paediatric traumatic stress and psychosocial care in the ED will help to overcome the current paucity of the literature. Finally, a system of peer support may accommodate wishes regarding staff care. Copyright © 2014 Elsevier Ltd. All rights reserved.

Single-Cell-Based Analysis Highlights a Surge in Cell-to-Cell Molecular Variability Preceding Irreversible Commitment in a Differentiation Process

PubMed Central

Boullu, Loïs; Morin, Valérie; Vallin, Elodie; Guillemin, Anissa; Papili Gao, Nan; Cosette, Jérémie; Arnaud, Ophélie; Kupiec, Jean-Jacques; Espinasse, Thibault

2016-01-01

In some recent studies, a view emerged that stochastic dynamics governing the switching of cells from one differentiation state to another could be characterized by a peak in gene expression variability at the point of fate commitment. We have tested this hypothesis at the single-cell level by analyzing primary chicken erythroid progenitors through their differentiation process and measuring the expression of selected genes at six sequential time-points after induction of differentiation. In contrast to population-based expression data, single-cell gene expression data revealed a high cell-to-cell variability, which was masked by averaging. We were able to show that the correlation network was a very dynamical entity and that a subgroup of genes tend to follow the predictions from the dynamical network biomarker (DNB) theory. In addition, we also identified a small group of functionally related genes encoding proteins involved in sterol synthesis that could act as the initial drivers of the differentiation. In order to assess quantitatively the cell-to-cell variability in gene expression and its evolution in time, we used Shannon entropy as a measure of the heterogeneity. Entropy values showed a significant increase in the first 8 h of the differentiation process, reaching a peak between 8 and 24 h, before decreasing to significantly lower values. Moreover, we observed that the previous point of maximum entropy precedes two paramount key points: an irreversible commitment to differentiation between 24 and 48 h followed by a significant increase in cell size variability at 48 h. In conclusion, when analyzed at the single cell level, the differentiation process looks very different from its classical population average view. New observables (like entropy) can be computed, the behavior of which is fully compatible with the idea that differentiation is not a “simple” program that all cells execute identically but results from the dynamical behavior of the underlying molecular network. PMID:28027290

Single-Cell-Based Analysis Highlights a Surge in Cell-to-Cell Molecular Variability Preceding Irreversible Commitment in a Differentiation Process.

PubMed

Richard, Angélique; Boullu, Loïs; Herbach, Ulysse; Bonnafoux, Arnaud; Morin, Valérie; Vallin, Elodie; Guillemin, Anissa; Papili Gao, Nan; Gunawan, Rudiyanto; Cosette, Jérémie; Arnaud, Ophélie; Kupiec, Jean-Jacques; Espinasse, Thibault; Gonin-Giraud, Sandrine; Gandrillon, Olivier

2016-12-01

In some recent studies, a view emerged that stochastic dynamics governing the switching of cells from one differentiation state to another could be characterized by a peak in gene expression variability at the point of fate commitment. We have tested this hypothesis at the single-cell level by analyzing primary chicken erythroid progenitors through their differentiation process and measuring the expression of selected genes at six sequential time-points after induction of differentiation. In contrast to population-based expression data, single-cell gene expression data revealed a high cell-to-cell variability, which was masked by averaging. We were able to show that the correlation network was a very dynamical entity and that a subgroup of genes tend to follow the predictions from the dynamical network biomarker (DNB) theory. In addition, we also identified a small group of functionally related genes encoding proteins involved in sterol synthesis that could act as the initial drivers of the differentiation. In order to assess quantitatively the cell-to-cell variability in gene expression and its evolution in time, we used Shannon entropy as a measure of the heterogeneity. Entropy values showed a significant increase in the first 8 h of the differentiation process, reaching a peak between 8 and 24 h, before decreasing to significantly lower values. Moreover, we observed that the previous point of maximum entropy precedes two paramount key points: an irreversible commitment to differentiation between 24 and 48 h followed by a significant increase in cell size variability at 48 h. In conclusion, when analyzed at the single cell level, the differentiation process looks very different from its classical population average view. New observables (like entropy) can be computed, the behavior of which is fully compatible with the idea that differentiation is not a "simple" program that all cells execute identically but results from the dynamical behavior of the underlying molecular network.

Coulomb repulsion in short polypeptides.

PubMed

Norouzy, Amir; Assaf, Khaleel I; Zhang, Shuai; Jacob, Maik H; Nau, Werner M

2015-01-08

Coulomb repulsion between like-charged side chains is presently viewed as a major force that impacts the biological activity of intrinsically disordered polypeptides (IDPs) by determining their spatial dimensions. We investigated short synthetic models of IDPs, purely composed of ionizable amino acid residues and therefore expected to display an extreme structural and dynamic response to pH variation. Two synergistic, custom-made, time-resolved fluorescence methods were applied in tandem to study the structure and dynamics of the acidic and basic hexapeptides Asp6, Glu6, Arg6, Lys6, and His6 between pH 1 and 12. (i) End-to-end distances were obtained from the short-distance Förster resonance energy transfer (sdFRET) from N-terminal 5-fluoro-l-tryptophan (FTrp) to C-terminal Dbo. (ii) End-to-end collision rates were obtained for the same peptides from the collision-induced fluorescence quenching (CIFQ) of Dbo by FTrp. Unexpectedly, the very high increase of charge density at elevated pH had no dynamical or conformational consequence in the anionic chains, neither in the absence nor in the presence of salt, in conflict with the common view and in partial conflict with accompanying molecular dynamics simulations. In contrast, the cationic peptides responded to ionization but with surprising patterns that mirrored the rich individual characteristics of each side chain type. The contrasting results had to be interpreted, by considering salt screening experiments, N-terminal acetylation, and simulations, in terms of an interplay of local dielectric constant and peptide-length dependent side chain charge-charge repulsion, side chain functional group solvation, N-terminal and side chain charge-charge repulsion, and side chain-side chain as well as side chain-backbone interactions. The common picture that emerged is that Coulomb repulsion between water-solvated side chains is efficiently quenched in short peptides as long as side chains are not in direct contact with each other or the main chain.

Age Stereotypes and Self-Views Revisited: Patterns of Internalization and Projection Processes Across the Life Span.

PubMed

Kornadt, Anna E; Voss, Peggy; Rothermund, Klaus

2017-07-01

We investigated processes of age stereotype internalization into the self and projection of self-views onto age stereotypes from a life-span perspective, taking age-related differences in the relevance of life domains into account. Age stereotypes and self-views in eight life domains were assessed in a sample of N = 593 persons aged 30-80 years (T1) at two time points that were separated by a 4-year time interval. We estimated cross-lagged projection and internalization effects in multigroup structural equation models. Internalization and projection effects were contingent on age group and life domain: Internalization effects were strongest in the young and middle-aged groups and emerged in the domains family, personality, work, and leisure. Projection effects in different domains were most pronounced for older participants. Our findings suggest that the internalization of age stereotypes is triggered by domain-specific expectations of impending age-related changes and transitions during certain phases of the life span. Projection processes, however, seem to occur in response to changes that have already been experienced by the individual. Our study demonstrates the dynamic interrelation of age stereotypes and self-views across the life course and highlights the importance of a differentiated, life-span perspective for the understanding of these mechanisms. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Theta EEG dynamics of the error-related negativity.

PubMed

Trujillo, Logan T; Allen, John J B

2007-03-01

The error-related negativity (ERN) is a response-locked brain potential (ERP) occurring 80-100ms following response errors. This report contrasts three views of the genesis of the ERN, testing the classic view that time-locked phasic bursts give rise to the ERN against the view that the ERN arises from a pure phase-resetting of ongoing theta (4-7Hz) EEG activity and the view that the ERN is generated - at least in part - by a phase-resetting and amplitude enhancement of ongoing theta EEG activity. Time-domain ERP analyses were augmented with time-frequency investigations of phase-locked and non-phase-locked spectral power, and inter-trial phase coherence (ITPC) computed from individual EEG trials, examining time courses and scalp topographies. Simulations based on the assumptions of the classic, pure phase-resetting, and phase-resetting plus enhancement views, using parameters from each subject's empirical data, were used to contrast the time-frequency findings that could be expected if one or more of these hypotheses adequately modeled the data. Error responses produced larger amplitude activity than correct responses in time-domain ERPs immediately following responses, as expected. Time-frequency analyses revealed that significant error-related post-response increases in total spectral power (phase- and non-phase-locked), phase-locked power, and ITPC were primarily restricted to the theta range, with this effect located over midfrontocentral sites, with a temporal distribution from approximately 150-200ms prior to the button press and persisting up to 400ms post-button press. The increase in non-phase-locked power (total power minus phase-locked power) was larger than phase-locked power, indicating that the bulk of the theta event-related dynamics were not phase-locked to response. Results of the simulations revealed a good fit for data simulated according to the phase-locking with amplitude enhancement perspective, and a poor fit for data simulated according to the classic view and the pure phase-resetting view. Error responses produce not only phase-locked increases in theta EEG activity, but also increases in non-phase-locked theta, both of which share a similar topography. The findings are thus consistent with the notion advanced by Luu et al. [Luu P, Tucker DM, Makeig S. Frontal midline theta and the error-related negativity; neurophysiological mechanisms of action regulation. Clin Neurophysiol 2004;115:1821-35] that the ERN emerges, at least in part, from a phase-resetting and phase-locking of ongoing theta-band activity, in the context of a general increase in theta power following errors.

Dynamics of backlight luminance for using smartphone in dark environment

NASA Astrophysics Data System (ADS)

Na, Nooree; Jang, Jiho; Suk, Hyeon-Jeong

2014-02-01

This study developed dynamic backlight luminance, which gradually changes as time passes for comfortable use of a smartphone display in a dark environment. The study was carried out in two stages. In the first stage, a user test was conducted to identify the optimal luminance by assessing the facial squint level, subjective glare evaluation, eye blink frequency and users' subjective preferences. Based on the results of the user test, the dynamics of backlight luminance was designed. It has two levels of luminance: the optimal level for initial viewing to avoid sudden glare or fatigue to users' eyes, and the optimal level for constant viewing, which is comfortable, but also bright enough for constant reading of the displayed material. The luminance for initial viewing starts from 10 cd/m2, and it gradually increases to 40 cd/m2 for users' visual comfort at constant viewing for 20 seconds; In the second stage, a validation test on dynamics of backlight luminance was conducted to verify the effectiveness of the developed dynamics. It involving users' subjective preferences, eye blink frequency, and brainwave analysis using the electroencephalogram (EEG) to confirm that the proposed dynamic backlighting enhances users' visual comfort and visual cognition, particularly for using smartphones in a dark environment.

Ultra-low dose quantitative CT myocardial perfusion imaging with sparse-view dynamic acquisition and image reconstruction: A feasibility study.

PubMed

Enjilela, Esmaeil; Lee, Ting-Yim; Hsieh, Jiang; Wisenberg, Gerald; Teefy, Patrick; Yadegari, Andrew; Bagur, Rodrigo; Islam, Ali; Branch, Kelley; So, Aaron

2018-03-01

We implemented and validated a compressed sensing (CS) based algorithm for reconstructing dynamic contrast-enhanced (DCE) CT images of the heart from sparsely sampled X-ray projections. DCE CT imaging of the heart was performed on five normal and ischemic pigs after contrast injection. DCE images were reconstructed with filtered backprojection (FBP) and CS from all projections (984-view) and 1/3 of all projections (328-view), and with CS from 1/4 of all projections (246-view). Myocardial perfusion (MP) measurements with each protocol were compared to those with the reference 984-view FBP protocol. Both the 984-view CS and 328-view CS protocols were in good agreements with the reference protocol. The Pearson correlation coefficients of 984-view CS and 328-view CS determined from linear regression analyses were 0.98 and 0.99 respectively. The corresponding mean biases of MP measurement determined from Bland-Altman analyses were 2.7 and 1.2ml/min/100g. When only 328 projections were used for image reconstruction, CS was more accurate than FBP for MP measurement with respect to 984-view FBP. However, CS failed to generate MP maps comparable to those with 984-view FBP when only 246 projections were used for image reconstruction. DCE heart images reconstructed from one-third of a full projection set with CS were minimally affected by aliasing artifacts, leading to accurate MP measurements with the effective dose reduced to just 33% of conventional full-view FBP method. The proposed CS sparse-view image reconstruction method could facilitate the implementation of sparse-view dynamic acquisition for ultra-low dose CT MP imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Online Assessment, Measurement and Evaluation: Emerging Practices

ERIC Educational Resources Information Center

Williams, David, Ed.; Hricko, Mary, Ed.; Howell, Scott, Ed.

2006-01-01

"Online Assessment, Measurement and Evaluation: Emerging Practices" provides a view of the possibilities and challenges facing online educators and evaluators in the 21st Century. As technology evolves and online measurement and assessment follow, "Online Assessment, Measurement and Evaluation: Emerging Practices" uses…

SMALL-SCALE STRUCTURING OF ELLERMAN BOMBS AT THE SOLAR LIMB

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

Nelson, C. J.; Doyle, J. G.; Scullion, E. M.

2015-01-01

Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disk. In this article, we make use of high-resolution, high-cadence observations of an Active Region at the solar limb, collected by the CRisp Imaging SpectroPolarimeter (CRISP) instrument, to identifymore » EBs and infer their physical properties. The upper atmosphere is also probed using the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). We analyze 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s{sup –1}, extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical ''flaring'' (changing in area and intensity) observed in on-disk events. Two in-depth case studies are also presented that highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the Hα line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the Hα line core, and are not observed by the SDO/AIA EUV filters.« less

Autonomy through identification: a qualitative study of the process of identification used by people with type 2 diabetes.

PubMed

Moser, Albine; van der Bruggen, Harry; Spreeuwenberg, Cor; Widdershoven, Guy

2008-04-01

The aim of this study is to clarify the process of identification with diabetes as a dimension of autonomy as described by people with type 2 diabetes. People with type 2 diabetes view autonomy as competency in shaping one's life. This concept of autonomy has seven dimensions, which emerged as categories in prior research. Dynamic processes shape these dimensions of autonomy. One of the dimensions of autonomy is identification. This study has a qualitative descriptive and exploratory design and an inductive approach as described in grounded theory. Data were collected by means of in-depth interviews. The sample consisted of 15 people with type 2 diabetes mellitus in a nurse-led, shared-care setting in the Netherlands. The phases of identification are comprehending, struggling, evaluating and mastering. Each phase has its own characteristics. Identifying with the diabetes is a non-linear, cyclical and continuous process because people with diabetes have to deal with changing conditions. The dynamics of identification is directed to a process of identifying with diabetes and its care requirement. Recognizing identification as an element of autonomy enables nurses to adopt a more patient-oriented view of autonomy. Nursing that fosters the process of identification promotes autonomy. This implies that a person with diabetes should be able to identify with the nurse's interventions. Hence it is vital that nurses build supportive partnerships when providing care for such a patient.

The Life-Changing Magic of Nonlinearity in Network Control

NASA Astrophysics Data System (ADS)

Cornelius, Sean

The proper functioning and reliability of many man-made and natural systems is fundamentally tied to our ability to control them. Indeed, applications as diverse as ecosystem management, emergency response and cell reprogramming all, at their heart, require us to drive a system to--or keep it in--a desired state. This process is complicated by the nonlinear dynamics inherent to most real systems, which has traditionally been viewed as the principle obstacle to their control. In this talk, I will discuss two ways in which nonlinearity turns this view on its head, in fact representing an asset to the control of complex systems. First, I will show how nonlinearity in the form of multistability allows one to systematically design control interventions that can deliberately induce ``reverse cascading failures'', in which a network spontaneously evolves to a desirable (rather than a failed) state. Second, I will show that nonlinearity in the form of time-varying dynamics unexpectedly makes temporal networks easier to control than their static counterparts, with the former enjoying dramatic and simultaneous reductions in all costs of control. This is true despite the fact that temporality tends to fragment a network's structure, disrupting the paths that allow the directly-controlled or ``driver'' nodes to communicate with the rest of the network. Taken together, these studies shed new light on the crucial role of nonlinearity in network control, and provide support to the idea we can control nonlinearity, rather than letting nonlinearity control us.

Emergence of the benefits and costs of grouping for visual search.

PubMed

Wu, Rachel; McGee, Brianna; Rubenstein, Madelyn; Pruitt, Zoe; Cheung, Olivia S; Aslin, Richard N

2018-04-16

The present study investigated how grouping related items leads to the emergence of benefits (facilitation when related items are search targets) and costs (interference when related items are distractors) in visual search. Participants integrated different views (related items) of a novel Lego object via (a) assembling the object, (b) disassembling the object, or (c) sitting quietly without explicit instructions. An omnibus ANOVA revealed that neural responses (N2pc ERP) for attentional selection increased between pretest to posttest regardless of the training condition when a specific target view appeared (benefit) and when a nontarget view from the same object as the target view appeared (cost). Bonferroni-corrected planned comparisons revealed that assembling the object (but not disassembling the object or no training) had a significant impact from pretest to posttest, although the ANOVA did not reveal any interaction effects, suggesting that the effects might not differ across training conditions. This study is one of the first to demonstrate the emergence of the costs and benefits of grouping novel targets on visual search efficiency. © 2018 Society for Psychophysiological Research.

The magnetosphere as system

NASA Astrophysics Data System (ADS)

Siscoe, G. L.

2012-12-01

What is a system? A group of elements interacting with each other so as to create feedback loops. A system gets complex as the number of feedback loops increases and as the feedback loops exhibit time delays. Positive and negative feedback loops with time delays can give a system intrinsic time dependence and emergent properties. A system generally has input and output flows of something (matter, energy, money), which, if time variable, add an extrinsic component to its behavior. The magnetosphere is a group of elements interacting through feedback loops, some with time delays, driven by energy and mass inflow from a variable solar wind and outflow into the atmosphere and solar wind. The magnetosphere is a complex system. With no solar wind, there is no behavior. With solar wind, there is behavior from intrinsic and extrinsic causes. As a contribution to taking a macroscopic view of magnetospheric dynamics, to treating the magnetosphere as a globally integrated, complex entity, I will discus the magnetosphere as a system, its feedback loops, time delays, emergent behavior, and intrinsic and extrinsic behavior modes.

The dynamics of folding instability in a constrained Cosserat medium

NASA Astrophysics Data System (ADS)

Gourgiotis, Panos A.; Bigoni, Davide

2017-04-01

Different from Cauchy elastic materials, generalized continua, and in particular constrained Cosserat materials, can be designed to possess extreme (near a failure of ellipticity) orthotropy properties and in this way to model folding in a three-dimensional solid. Following this approach, folding, which is a narrow zone of highly localized bending, spontaneously emerges as a deformation pattern occurring in a strongly anisotropic solid. How this peculiar pattern interacts with wave propagation in the time-harmonic domain is revealed through the derivation of an antiplane, infinite-body Green's function, which opens the way to integral techniques for anisotropic constrained Cosserat continua. Viewed as a perturbing agent, the Green's function shows that folding, emerging near a steadily pulsating source in the limit of failure of ellipticity, is transformed into a disturbance with wavefronts parallel to the folding itself. The results of the presented study introduce the possibility of exploiting constrained Cosserat solids for propagating waves in materials displaying origami patterns of deformation. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.'

HIMSS Venture+ Forum and HX360 Provide Industry View of Health Technology Innovation, Startup and Investment Activity; Advancing the New Model of Care.

PubMed

Burde, Howard A; Scarfo, Richard

2015-01-01

Presented by HIMSS, the Venture+ Forum program and pitch competition provides a 360-degree view on health technology investing and today's top innovative companies. It features exciting 3-minute pitch presentations from emerging and growth-stage companies, investor panels and a networking reception. Recent Venture+ Forum winners include TowerView Health, Prima-Temp, ActuaiMeds and M3 Clinician. As an industry catalyst for health IT innovation and business-building resource for growing companies and emerging technology solutions, HIMSS has co-developed with A VIA, a new initiative that addresses how emerging technologies, health system business model changes and investment will transform the delivery of care. HX360 engages senior healthcare leaders, innovation teams, investors and entrepreneurs around the vision of transforming healthcare delivery by leveraging technology, process and structure.

What's in a wait? Contrasting management science and economic perspectives on waiting for emergency care.

PubMed

Morton, Alec; Bevan, Gwyn

2008-02-01

The current paper reviews and contrasts a management science view of waiting for healthcare, which centres on queues as devices for buffering demand, with an economic view, which stresses the role of the incentive structure, in the context of English Accident and Emergency Departments. We demonstrate that the management science view provides insight into waiting time performance within a single facility but is limited in its ability to shed light on variations in performance across facilities. We argue, with reference to supporting data, that such variations may be explainable by a proper understanding of the incentive structure in A&E Departments.

Taking Emergence Seriously: The Centrality of Circular Causality for Dynamic Systems Approaches to Development

ERIC Educational Resources Information Center

Witherington, David C.

2011-01-01

The dynamic systems (DS) approach has emerged as an influential and potentially unifying metatheory for developmental science. Its central platform--the argument against design--suggests that structure spontaneously and without prescription emerges through self-organization. In one of the most prominent accounts of DS, Thelen and her colleagues…

On the Interplay between Order Parameter Dynamics and System Parameter Dynamics in Human Perceptual-Cognitive-Behavioral Systems.

PubMed

Frank, T D

2015-04-01

Previous research has demonstrated that perceiving, thinking, and acting are human activities that correspond to self-organized patterns. The emergence of such patterns can be completely described in terms of the dynamics of the pattern amplitudes, which are referred to as order parameters. The patterns emerge at bifurcations points when certain system parameters internal and external to a human agent exceed critical values. At issue is how one might study the order parameter dynamics for sequences of consecutive, emergent perceptual, cognitive, or behavioral activities. In particular, these activities may in turn impact the system parameters that have led to the emergence of the activities in the first place. This interplay between order parameter dynamics and system parameter dynamics is discussed in general and formulated in mathematical terms. Previous work that has made use of this two-tiered framework of order parameter and system parameter dynamics are briefly addressed. As an application, a model for perception under functional fixedness is presented. Finally, it is argued that the phenomena that emerge in this framework and can be observed when human agents perceive, think, and act are just as likely to occur in pattern formation systems of the inanimate world. Consequently, these phenomena do not necessarily have a neurophysiological basis but should instead be understood from the perspective of the theory of self-organization.

Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

PubMed

Lehn, Jean-Marie

2012-01-01

Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

Brain dynamics during natural viewing conditions--a new guide for mapping connectivity in vivo.

PubMed

Bartels, Andreas; Zeki, Semir

2005-01-15

We describe here a new way of obtaining maps of connectivity in the human brain based on interregional correlations of blood oxygen level-dependent (BOLD) signal during natural viewing conditions. We propose that anatomical connections are reflected in BOLD signal correlations during natural brain dynamics. This may provide a powerful approach to chart connectivity, more so than that based on the 'resting state' of the human brain, and it may complement diffusion tensor imaging. Our approach relies on natural brain dynamics and is therefore experimentally unbiased and independent of hypothesis-driven, specialized stimuli. It has the advantage that natural viewing leads to considerably stronger cortical activity than rest, thus facilitating detection of weaker connections. To validate our technique, we used functional magnetic resonance imaging (fMRI) to record BOLD signal while volunteers freely viewed a movie that was interrupted by resting periods. We used independent component analysis (ICA) to segregate cortical areas before characterizing the dynamics of their BOLD signal during free viewing and rest. Natural viewing and rest each revealed highly specific correlation maps, which reflected known anatomical connections. Examples are homologous regions in visual and auditory cortices in the two hemispheres and the language network consisting of Wernicke's area, Broca's area, and a premotor region. Correlations between regions known to be directly connected were always substantially higher than between nonconnected regions. Furthermore, compared to rest, natural viewing specifically increased correlations between anatomically connected regions while it decreased correlations between nonconnected regions. Our findings therefore demonstrate that natural viewing conditions lead to particularly specific interregional correlations and thus provide a powerful environment to reveal anatomical connectivity in vivo.

["Hormone bomb": risks of emergency contraception from the perspective of pharmacy attendants in Rio de Janeiro, Brazil].

PubMed

Brandão, Elaine Reis; Cabral, Cristiane da Silva; Ventura, Miriam; Paiva, Sabrina Pereira; Bastos, Luiza Lena; Oliveira, Naira Villas Boas Vidal de; Szabo, Iolanda

2016-09-19

This study focused on views towards emergency contraception among pharmacy attendants in Greater Metropolitan Rio de Janeiro, Brazil. The empirical material came from a socio-anthropological study with 20 semi-structured interviews of pharmacy attendants of both sexes (8 females and 12 males). The interviews showed negative views of emergency contraception, emphasizing its potential health risks. Interviews considered emergency contraception a "hormone bomb" that can harm the female reproductive organs and other organ systems. The pharmacy attendants highlighted the risks of "uncontrolled" or "indiscriminate" use, especially by adolescents and young women. Since they considered it "dangerous" to women's bodies, they assigned the responsibility for orientation and counseling on use of the method to gynecologists rather than to pharmacists. The article discusses the need to expand the public debate on emergency contraception in Brazil to include pharmacists and pharmacy attendants, in addition to health professionals in general and teachers.

Counseling Psychologists Who View Their Careers as a Calling: A Qualitative Study

ERIC Educational Resources Information Center

Duffy, Ryan D.; Foley, Pamela F.; Raque-Bodgan, Trisha L.; Reid-Marks, Laura; Dik, Bryan J.; Castano, Megan C.; Adams, Christopher M.

2012-01-01

Interviews were completed with eight counseling psychologists who viewed their careers as a calling. Using the Consensual Qualitative Research guidelines, six domains emerged: definition, process of discerning, content of the calling, professional impact, personal impact, and maintenance. Generally, interviewees viewed the discernment of their…

Revisiting Code-Switching Practice in TESOL: A Critical Perspective

ERIC Educational Resources Information Center

Wang, Hao; Mansouri, Behzad

2017-01-01

In academic circles, the "English Only" view and "Balanced view" have established their grounds after volumes of work on the topic of code-switching in TESOL. With recent development in Critical Applied Linguistics, poststructural theory, postmodern theory, and the emergence of multilingualism, scholars have begun to view ELT…

Fire, Death, and Rebirth: A Metaphoric Analysis of the 1988 Yellowstone Fire Debate.

ERIC Educational Resources Information Center

Hardy-Short, Dayle C.; Short, C. Brant

1995-01-01

Finds that two primary archetypal metaphors--death and rebirth--emerged in the public debate concerning management of the 1988 Yellowstone forest fires. Argues that the crisis brought two competing views of public land management to the forefront: the ecological view, and the human-centered view. (SR)

Catenary-induced geometric nonlinearity effects on cable linear vibrations

NASA Astrophysics Data System (ADS)

Mansour, Achref; Mekki, Othman Ben; Montassar, Sami; Rega, Giuseppe

2018-01-01

This paper investigates the free undamped vibrations of cables of arbitrary sag and inclination according to the catenary theory. The proposed approach accounts for the catenary effect on the static profile around which the cable motion is defined. Considering first order geometric nonlinearities, exact expression of the curvature is obtained along with the ensuing correction of the well known Irvine parameter. Taking into account the new characterization, different regions of shallow and non-shallow profiles are identified for various inclinations. In view of such classification, the analysis carried out on cable linear modal properties shows the emergence of new dynamic features such as additional hybrid modes and internal resonances. Analytical and numerical results reduce to those obtained by classic formulations in the cases of both horizontal and inclined shallow/non-shallow cables.

Island biogeography: Taking the long view of nature's laboratories.

PubMed

Whittaker, Robert J; Fernández-Palacios, José María; Matthews, Thomas J; Borregaard, Michael K; Triantis, Kostas A

2017-09-01

Islands provide classic model biological systems. We review how growing appreciation of geoenvironmental dynamics of marine islands has led to advances in island biogeographic theory accommodating both evolutionary and ecological phenomena. Recognition of distinct island geodynamics permits general models to be developed and modified to account for patterns of diversity, diversification, lineage development, and trait evolution within and across island archipelagos. Emergent patterns of diversity include predictable variation in island species-area relationships, progression rule colonization from older to younger land masses, and syndromes including loss of dispersability and secondary woodiness in herbaceous plant lineages. Further developments in Earth system science, molecular biology, and trait data for islands hold continued promise for unlocking many of the unresolved questions in evolutionary biology and biogeography. Copyright © 2017, American Association for the Advancement of Science.

From the Influence of Traumas to Therapeutic Letting Go: The Contribution of Hypnosis and EMDR.

PubMed

Masson, Joanic; Bernoussi, Amal; Regourd-Laizeau, Martine

2016-01-01

The development of new psychotherapies such as Eye Movement Desensitization and Reprocessing (EDMR) has led to numerous fresh approaches to both the treatment of trauma and to the understanding of underlying psychopathology. A unified view appears to be slowly emerging in an attempt to corroborate clinical practice with neurobiological data. This article attempts to demonstrate links between alternate psychotherapies by highlighting what appears to be an invariant among these approaches, namely "letting go." This concept refers to a psycho-physical dynamic that combines psychological dissociation and reassociation, as well as the body's vagotonic mechanisms. Following an explanation of this process, it is demonstrated how letting go can manifest itself physiologically and why this may be significant in the study of trauma.

The Sla2p/HIP1/HIP1R family: similar structure, similar function in endocytosis?

PubMed

Gottfried, Irit; Ehrlich, Marcelo; Ashery, Uri

2010-02-01

HIP1 (huntingtin interacting protein 1) has two close relatives: HIP1R (HIP1-related) and yeast Sla2p. All three members of the family have a conserved domain structure, suggesting a common function. Over the past decade, a number of studies have characterized these proteins using a combination of biochemical, imaging, structural and genetic techniques. These studies provide valuable information on binding partners, structure and dynamics of HIP1/HIP1R/Sla2p. In general, all suggest a role in CME (clathrin-mediated endocytosis) for the three proteins, though some differences have emerged. In this mini-review we summarize the current views on the roles of these proteins, while emphasizing the unique attributes of each family member.

Dynamics of bloggers’ communities: Bipartite networks from empirical data and agent-based modeling

NASA Astrophysics Data System (ADS)

Mitrović, Marija; Tadić, Bosiljka

2012-11-01

We present an analysis of the empirical data and the agent-based modeling of the emotional behavior of users on the Web portals where the user interaction is mediated by posted comments, like Blogs and Diggs. We consider the dataset of discussion-driven popular Diggs, in which all comments are screened by machine-learning emotion detection in the text, to determine positive and negative valence (attractiveness and aversiveness) of each comment. By mapping the data onto a suitable bipartite network, we perform an analysis of the network topology and the related time-series of the emotional comments. The agent-based model is then introduced to simulate the dynamics and to capture the emergence of the emotional behaviors and communities. The agents are linked to posts on a bipartite network, whose structure evolves through their actions on the posts. The emotional states (arousal and valence) of each agent fluctuate in time, subject to the current contents of the posts to which the agent is exposed. By an agent’s action on a post its current emotions are transferred to the post. The model rules and the key parameters are inferred from the considered empirical data to ensure their realistic values and mutual consistency. The model assumes that the emotional arousal over posts drives the agent’s action. The simulations are preformed for the case of constant flux of agents and the results are analyzed in full analogy with the empirical data. The main conclusions are that the emotion-driven dynamics leads to long-range temporal correlations and emergent networks with community structure, that are comparable with the ones in the empirical system of popular posts. In view of pure emotion-driven agents actions, this type of comparisons provide a quantitative measure for the role of emotions in the dynamics on real blogs. Furthermore, the model reveals the underlying mechanisms which relate the post popularity with the emotion dynamics and the prevalence of negative emotions (critique). We also demonstrate how the community structure is tuned by varying a relevant parameter in the model. All data used in these works are fully anonymized.

Curved backgrounds in emergent gravity

NASA Astrophysics Data System (ADS)

Chaurasia, Shikha; Erlich, Joshua; Zhou, Yiyu

2018-06-01

Field theories that are generally covariant but nongravitational at tree level typically give rise to an emergent gravitational interaction whose strength depends on a physical regulator. We consider emergent gravity models in which scalar fields assume the role of clock and rulers, addressing the problem of time in quantum gravity. We discuss the possibility of nontrivial dynamics for clock and ruler fields, and describe some of the consequences of those dynamics for the emergent gravitational theory.

The "Emerging" and "Emergent" Present: A View on the Indeterminate Nature of Mathematics Lessons

ERIC Educational Resources Information Center

Roth, Wolff-Michael; Maheux, Jean-François

2014-01-01

The notion of emergence has considerable currency in mathematics education. However, the notion tends to be used in a descriptive way rather than being theorized and developed as a phenomenon sui generis. The purpose of this article is to contribute to building a theory of "emergence." After providing an exemplifying description and…

Defending Qualitative Change: The View from Dynamical Systems Theory

ERIC Educational Resources Information Center

Spencer, John P.; Perone, Sammy

2008-01-01

A central controversy in developmental science, enflamed by nativist accounts, is whether development is best viewed as a series of qualitative or continuous changes. This article defends the notion of qualitative change from the perspective of dynamical systems theory (DST). Qualitative change within DST refers to the shift that occurs when a…

How Formal Dynamic Verification Tools Facilitate Novel Concurrency Visualizations

NASA Astrophysics Data System (ADS)

Aananthakrishnan, Sriram; Delisi, Michael; Vakkalanka, Sarvani; Vo, Anh; Gopalakrishnan, Ganesh; Kirby, Robert M.; Thakur, Rajeev

With the exploding scale of concurrency, presenting valuable pieces of information collected by formal verification tools intuitively and graphically can greatly enhance concurrent system debugging. Traditional MPI program debuggers present trace views of MPI program executions. Such views are redundant, often containing equivalent traces that permute independent MPI calls. In our ISP formal dynamic verifier for MPI programs, we present a collection of alternate views made possible by the use of formal dynamic verification. Some of ISP’s views help pinpoint errors, some facilitate discerning errors by eliminating redundancy, while others help understand the program better by displaying concurrent even orderings that must be respected by all MPI implementations, in the form of completes-before graphs. In this paper, we describe ISP’s graphical user interface (GUI) capabilities in all these areas which are currently supported by a portable Java based GUI, a Microsoft Visual Studio GUI, and an Eclipse based GUI whose development is in progress.

Dynamic high-speed acquisition system design of transmission error with USB based on LabVIEW and FPGA

NASA Astrophysics Data System (ADS)

Zheng, Yong; Chen, Yan

2013-10-01

To realize the design of dynamic acquisition system for real-time detection of transmission chain error is very important to improve the machining accuracy of machine tool. In this paper, the USB controller and FPGA is used for hardware platform design, combined with LabVIEW to design user applications, NI-VISA is taken for develop USB drivers, and ultimately achieve the dynamic acquisition system design of transmission error

A Neural-Dynamic Architecture for Concurrent Estimation of Object Pose and Identity

PubMed Central

Lomp, Oliver; Faubel, Christian; Schöner, Gregor

2017-01-01

Handling objects or interacting with a human user about objects on a shared tabletop requires that objects be identified after learning from a small number of views and that object pose be estimated. We present a neurally inspired architecture that learns object instances by storing features extracted from a single view of each object. Input features are color and edge histograms from a localized area that is updated during processing. The system finds the best-matching view for the object in a novel input image while concurrently estimating the object’s pose, aligning the learned view with current input. The system is based on neural dynamics, computationally operating in real time, and can handle dynamic scenes directly off live video input. In a scenario with 30 everyday objects, the system achieves recognition rates of 87.2% from a single training view for each object, while also estimating pose quite precisely. We further demonstrate that the system can track moving objects, and that it can segment the visual array, selecting and recognizing one object while suppressing input from another known object in the immediate vicinity. Evaluation on the COIL-100 dataset, in which objects are depicted from different viewing angles, revealed recognition rates of 91.1% on the first 30 objects, each learned from four training views. PMID:28503145

Dynamic Environmental Photosynthetic Imaging Reveals Emergent Phenotypes

DOE PAGES

Cruz, Jeffrey A.; Savage, Linda J.; Zegarac, Robert; ...

2016-06-22

Understanding and improving the productivity and robustness of plant photosynthesis requires high-throughput phenotyping under environmental conditions that are relevant to the field. Here we demonstrate the dynamic environmental photosynthesis imager (DEPI), an experimental platform for integrated, continuous, and high-throughput measurements of photosynthetic parameters during plant growth under reproducible yet dynamic environmental conditions. Using parallel imagers obviates the need to move plants or sensors, reducing artifacts and allowing simultaneous measurement on large numbers of plants. As a result, DEPI can reveal phenotypes that are not evident under standard laboratory conditions but emerge under progressively more dynamic illumination. We show examples inmore » mutants of Arabidopsis of such “emergent phenotypes” that are highly transient and heterogeneous, appearing in different leaves under different conditions and depending in complex ways on both environmental conditions and plant developmental age. Finally, these emergent phenotypes appear to be caused by a range of phenomena, suggesting that such previously unseen processes are critical for plant responses to dynamic environments.« less

Social-media-enabled learning in emergency medicine: a case study of the growth, engagement and impact of a free open access medical education blog.

PubMed

Carley, Simon; Beardsell, Iain; May, Natalie; Crowe, Liz; Baombe, Janos; Grayson, Alan; Carden, Richard; Liebig, Ashley; Gray, Chris; Fisher, Ross; Horner, Daniel; Howard, Laura; Body, Richard

2018-02-01

Clinicians are increasingly using social media for professional development and education. In 2012, we developed the St.Emlyn's blog, an open access resource dedicated to providing free education in the field of emergency medicine. To describe the development and growth of this international emergency medicine blog. We present a narrative description of the development of St.Emlyn's blog. Data on scope, impact and engagement were extracted from WordPress, Twitter and Google Analytics. The St.Emlyn's blog demonstrates a sustained growth in size and user engagement. Since inception in 2012, the site has been viewed over 1.25 million times with a linear year-on-year growth. We have published over 500 blog posts, each of which attracts a mean of 2466 views (range 382-69 671). The site has been viewed in nearly every country in the world, although the majority (>75%) of visitors come from the USA, UK and Australia. This case study of an emergency medicine blog quantifies the reach and engagement of social-media-enabled learning in emergency medicine. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Web-Based Real-Time Emergency Monitoring

NASA Technical Reports Server (NTRS)

Harvey, Craig A.; Lawhead, Joel

2007-01-01

The Web-based Real-Time Asset Monitoring (RAM) module for emergency operations and facility management enables emergency personnel in federal agencies and local and state governments to monitor and analyze data in the event of a natural disaster or other crisis that threatens a large number of people and property. The software can manage many disparate sources of data within a facility, city, or county. It was developed on industry-standard Geo- Spatial software and is compliant with open GIS standards. RAM View can function as a standalone system, or as an integrated plugin module to Emergency Operations Center (EOC) software suites such as REACT (Real-time Emergency Action Coordination Tool), thus ensuring the widest possible distribution among potential users. RAM has the ability to monitor various data sources, including streaming data. Many disparate systems are included in the initial suite of supported hardware systems, such as mobile GPS units, ambient measurements of temperature, moisture and chemical agents, flow meters, air quality, asset location, and meteorological conditions. RAM View displays real-time data streams such as gauge heights from the U.S. Geological Survey gauging stations, flood crests from the National Weather Service, and meteorological data from numerous sources. Data points are clearly visible on the map interface, and attributes as specified in the user requirements can be viewed and queried.

Emergence of ultrafast sparsely synchronized rhythms and their responses to external stimuli in an inhomogeneous small-world complex neuronal network.

PubMed

Kim, Sang-Yoon; Lim, Woochang

2017-09-01

We consider an inhomogeneous small-world network (SWN) composed of inhibitory short-range (SR) and long-range (LR) interneurons, and investigate the effect of network architecture on emergence of synchronized brain rhythms by varying the fraction of LR interneurons p long . The betweenness centralities of the LR and SR interneurons (characterizing the potentiality in controlling communication between other interneurons) are distinctly different. Hence, in view of the betweenness, SWNs we consider are inhomogeneous, unlike the "canonical" Watts-Strogatz SWN with nearly the same betweenness centralities. For small p long , the load of communication traffic is much concentrated on a few LR interneurons. However, as p long is increased, the number of LR connections (coming from LR interneurons) increases, and then the load of communication traffic is less concentrated on LR interneurons, which leads to better efficiency of global communication between interneurons. Sparsely synchronized rhythms are thus found to emerge when passing a small critical value p long (c) (≃0.16). The population frequency of the sparsely synchronized rhythm is ultrafast (higher than 100 Hz), while the mean firing rate of individual interneurons is much lower (∼30 Hz) due to stochastic and intermittent neural discharges. These dynamical behaviors in the inhomogeneous SWN are also compared with those in the homogeneous Watts-Strogatz SWN, in connection with their network topologies. Particularly, we note that the main difference between the two types of SWNs lies in the distribution of betweenness centralities. Unlike the case of the Watts-Strogatz SWN, dynamical responses to external stimuli vary depending on the type of stimulated interneurons in the inhomogeneous SWN. We consider two cases of external time-periodic stimuli applied to sub-populations of the LR and SR interneurons, respectively. Dynamical responses (such as synchronization suppression and enhancement) to these two cases of stimuli are studied and discussed in relation to the betweenness centralities of stimulated interneurons, representing the effectiveness for transfer of stimulation effect in the whole network. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adaptive control of structural balance for complex dynamical networks based on dynamic coupling of nodes

NASA Astrophysics Data System (ADS)

Gao, Zilin; Wang, Yinhe; Zhang, Lili

2018-02-01

In the existing research results of the complex dynamical networks controlled, the controllers are mainly used to guarantee the synchronization or stabilization of the nodes’ state, and the terms coupled with connection relationships may affect the behaviors of nodes, this obviously ignores the dynamic common behavior of the connection relationships between the nodes. In fact, from the point of view of large-scale system, a complex dynamical network can be regarded to be composed of two time-varying dynamic subsystems, which can be called the nodes subsystem and the connection relationships subsystem, respectively. Similar to the synchronization or stabilization of the nodes subsystem, some characteristic phenomena can be also emerged in the connection relationships subsystem. For example, the structural balance in the social networks and the synaptic facilitation in the biological neural networks. This paper focuses on the structural balance in dynamic complex networks. Generally speaking, the state of the connection relationships subsystem is difficult to be measured accurately in practical applications, and thus it is not easy to implant the controller directly into the connection relationships subsystem. It is noted that the nodes subsystem and the relationships subsystem are mutually coupled, which implies that the state of the connection relationships subsystem can be affected by the controllable state of nodes subsystem. Inspired by this observation, by using the structural balance theory of triad, the controller with the parameter adaptive law is proposed for the nodes subsystem in this paper, which may ensure the connection relationship matrix to approximate a given structural balance matrix in the sense of the uniformly ultimately bounded (UUB). That is, the structural balance may be obtained by employing the controlling state of the nodes subsystem. Finally, the simulations are used to show the validity of the method in this paper.

Relativistic impulse dynamics.

PubMed

Swanson, Stanley M

2011-08-01

Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.

Nucleon Viewed as a Borromean Bound-State

NASA Astrophysics Data System (ADS)

Segovia, Jorge; Mezrag, Cédric; Chang, Lei; Roberts, Craig D.

2018-05-01

We explain how the emergent phenomenon of dynamical chiral symmetry breaking ensures that Poincaré covariant analyses of the three valence-quark scattering problem in continuum quantum field theory yield a picture of the nucleon as a Borromean bound-state, in which binding arises primarily through the sum of two separate contributions. One involves aspects of the non-Abelian character of Quantum Chromodynamics that are expressed in the strong running coupling and generate tight, dynamical color-antitriplet quark-quark correlations in the scalar-isoscalar and pseudovector-isotriplet channels. This attraction is magnified by quark exchange associated with diquark breakup and reformation, which is required in order to ensure that each valence-quark participates in all diquark correlations to the complete extent allowed by its quantum numbers. Combining these effects, we arrive at a properly antisymmetrised Faddeev wave function for the nucleon and calculate, e.g. the flavor-separated versions of the Dirac and Pauli form factors and the proton's leading-twist parton distribution amplitude. We conclude that available data and planned experiments are capable of validating the proposed picture.

Magneto-Plasmonics and Resonant Interaction of Light with Dynamic Magnetisation in Metallic and All-Magneto-Dielectric Nanostructures

PubMed Central

Maksymov, Ivan S.

2015-01-01

A significant interest in combining plasmonics and magnetism at the nanoscale gains momentum in both photonics and magnetism sectors that are concerned with the resonant enhancement of light-magnetic-matter interaction in nanostructures. These efforts result in a considerable amount of literature, which is difficult to collect and digest in limited time. Furthermore, there is insufficient exchange of results between the two research sectors. Consequently, the goal of this review paper is to bridge this gap by presenting an overview of recent progress in the field of magneto-plasmonics from two different points of view: magneto-plasmonics, and magnonics and magnetisation dynamics. It is expected that this presentation style will make this review paper of particular interest to both general physical audience and specialists conducting research on photonics, plasmonics, Brillouin light scattering spectroscopy of magnetic nanostructures and magneto-optical Kerr effect magnetometry, as well as ultrafast all-optical and THz-wave excitation of spin waves. Moreover, readers interested in a new, rapidly emerging field of all-dielectric nanophotonics will find a section about all-magneto-dielectric nanostructures. PMID:28347027

Magneto-Plasmonics and Resonant Interaction of Light with Dynamic Magnetisation in Metallic and All-Magneto-Dielectric Nanostructures.

PubMed

Maksymov, Ivan S

2015-04-09

A significant interest in combining plasmonics and magnetism at the nanoscale gains momentum in both photonics and magnetism sectors that are concerned with the resonant enhancement of light-magnetic-matter interaction in nanostructures. These efforts result in a considerable amount of literature, which is difficult to collect and digest in limited time. Furthermore, there is insufficient exchange of results between the two research sectors. Consequently, the goal of this review paper is to bridge this gap by presenting an overview of recent progress in the field of magneto-plasmonics from two different points of view: magneto-plasmonics, and magnonics and magnetisation dynamics. It is expected that this presentation style will make this review paper of particular interest to both general physical audience and specialists conducting research on photonics, plasmonics, Brillouin light scattering spectroscopy of magnetic nanostructures and magneto-optical Kerr effect magnetometry, as well as ultrafast all-optical and THz-wave excitation of spin waves. Moreover, readers interested in a new, rapidly emerging field of all-dielectric nanophotonics will find a section about all-magneto-dielectric nanostructures.

Crustal permeability: Introduction to the special issue

USGS Publications Warehouse

Ingebritsen, Steven E.; Gleeson, Tom

2015-01-01

The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

Clustered marginalization of minorities during social transitions induced by co-evolution of behaviour and network structure

PubMed Central

Schleussner, Carl-Friedrich; Donges, Jonathan F.; Engemann, Denis A.; Levermann, Anders

2016-01-01

Large-scale transitions in societies are associated with both individual behavioural change and restructuring of the social network. These two factors have often been considered independently, yet recent advances in social network research challenge this view. Here we show that common features of societal marginalization and clustering emerge naturally during transitions in a co-evolutionary adaptive network model. This is achieved by explicitly considering the interplay between individual interaction and a dynamic network structure in behavioural selection. We exemplify this mechanism by simulating how smoking behaviour and the network structure get reconfigured by changing social norms. Our results are consistent with empirical findings: The prevalence of smoking was reduced, remaining smokers were preferentially connected among each other and formed increasingly marginalized clusters. We propose that self-amplifying feedbacks between individual behaviour and dynamic restructuring of the network are main drivers of the transition. This generative mechanism for co-evolution of individual behaviour and social network structure may apply to a wide range of examples beyond smoking. PMID:27510641

Children's Understanding of the War in Iraq: Views from Britain and Bosnia

ERIC Educational Resources Information Center

Roberts, Ron; Becirevic, Majda; Baker, Tracy

2009-01-01

Sixty-one children (aged 9-17) from the United Kingdom (31) and Bosnia (30) were interviewed about the war in Iraq. Significant differences emerged in their views of the war. The Bosnian children were more affected by the Iraq War, more aware of who is involved in it, had different views about its causes, viewed the consequences of the war with…

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.

The shifting appearance/disappearance of holographic images and the dynamic ontology of perceptual and cognitive processes

NASA Astrophysics Data System (ADS)

Boissonnet, Philippe

2013-02-01

The French philosopher M Merleau-Ponty captured the dynamic of perception with his idea of the intertwining of perceiver and perceived. Light is what links them. In the case of holographic images, not only is spatial and colour perception the pure product of light, but this light information is always in the process of self-construction with our eyes, according to our movements and the point of view adopted. According to the aesthetic reception of a work of art, Holographic images vary greatly from those of cinema, photography and even every kind of digital 3D animation. This particular image's status truly makes perceptually apparent the "co-emergence" of light and our gaze. But holography never misleads us with respect to the precarious nature of our perceptions. We have no illusion as to the limits of our empirical understanding of the perceived reality. Holography, like our knowledge of the visible, thus brings to light the phenomenon of reality's "co-constitution" and contributes to a dynamic ontology of perceptual and cognitive processes. The cognitivist Francico Varela defines this as the paradigm of enaction,i which I will adapt and apply to the appearance/disappearance context of holographic images to bring out their affinities on a metaphorical level.

Social Insects: A Model System for Network Dynamics

NASA Astrophysics Data System (ADS)

Charbonneau, Daniel; Blonder, Benjamin; Dornhaus, Anna

Social insect colonies (ants, bees, wasps, and termites) show sophisticated collective problem-solving in the face of variable constraints. Individuals exchange information and materials such as food. The resulting network structure and dynamics can inform us about the mechanisms by which the insects achieve particular collective behaviors and these can be transposed to man-made and social networks. We discuss how network analysis can answer important questions about social insects, such as how effective task allocation or information flow is realized. We put forward the idea that network analysis methods are under-utilized in social insect research, and that they can provide novel ways to view the complexity of collective behavior, particularly if network dynamics are taken into account. To illustrate this, we present an example of network tasks performed by ant workers, linked by instances of workers switching from one task to another. We show how temporal network analysis can propose and test new hypotheses on mechanisms of task allocation, and how adding temporal elements to static networks can drastically change results. We discuss the benefits of using social insects as models for complex systems in general. There are multiple opportunities emergent technologies and analysis methods in facilitating research on social insect network. The potential for interdisciplinary work could significantly advance diverse fields such as behavioral ecology, computer sciences, and engineering.

Dynamic neural networking as a basis for plasticity in the control of heart rate.

PubMed

Kember, G; Armour, J A; Zamir, M

2013-01-21

A model is proposed in which the relationship between individual neurons within a neural network is dynamically changing to the effect of providing a measure of "plasticity" in the control of heart rate. The neural network on which the model is based consists of three populations of neurons residing in the central nervous system, the intrathoracic extracardiac nervous system, and the intrinsic cardiac nervous system. This hierarchy of neural centers is used to challenge the classical view that the control of heart rate, a key clinical index, resides entirely in central neuronal command (spinal cord, medulla oblongata, and higher centers). Our results indicate that dynamic networking allows for the possibility of an interplay among the three populations of neurons to the effect of altering the order of control of heart rate among them. This interplay among the three levels of control allows for different neural pathways for the control of heart rate to emerge under different blood flow demands or disease conditions and, as such, it has significant clinical implications because current understanding and treatment of heart rate anomalies are based largely on a single level of control and on neurons acting in unison as a single entity rather than individually within a (plastically) interconnected network. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evolutionary history of Pacific salmon in dynamic environments

PubMed Central

Waples, Robin S; Pess, George R; Beechie, Tim

2008-01-01

Contemporary evolution of Pacific salmon (Oncorhynchus spp.) is best viewed in the context of the evolutionary history of the species and the dynamic ecosystems they inhabit. Speciation was complete by the late Miocene, leaving c. six million years for intraspecific diversification. Following the most recent glacial maximum, large areas became available for recolonization. Current intraspecific diversity is thus the product of recent evolution overlaid onto divergent historical lineages forged during recurrent episodes of Pleistocene glaciation. In northwestern North America, dominant habitat features have been relatively stable for the past 5000 years, but salmon ecosystems remain dynamic because of disturbance regimes (volcanic eruptions, landslides, wildfires, floods, variations in marine and freshwater productivity) that occur on a variety of temporal and spatial scales. These disturbances both create selective pressures for adaptive responses by salmon and inhibit long-term divergence by periodically extirpating local populations and creating episodic dispersal events that erode emerging differences. Recent anthropogenic changes are replicated pervasively across the landscape and interrupt processes that allow natural habitat recovery. If anthropogenic changes can be shaped to produce disturbance regimes that more closely mimic (in both space and time) those under which the species evolved, Pacific salmon should be well-equipped to deal with future challenges, just as they have throughout their evolutionary history. PMID:25567626

Similarity-Based Fusion of MEG and fMRI Reveals Spatio-Temporal Dynamics in Human Cortex During Visual Object Recognition

PubMed Central

Cichy, Radoslaw Martin; Pantazis, Dimitrios; Oliva, Aude

2016-01-01

Every human cognitive function, such as visual object recognition, is realized in a complex spatio-temporal activity pattern in the brain. Current brain imaging techniques in isolation cannot resolve the brain's spatio-temporal dynamics, because they provide either high spatial or temporal resolution but not both. To overcome this limitation, we developed an integration approach that uses representational similarities to combine measurements of magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) to yield a spatially and temporally integrated characterization of neuronal activation. Applying this approach to 2 independent MEG–fMRI data sets, we observed that neural activity first emerged in the occipital pole at 50–80 ms, before spreading rapidly and progressively in the anterior direction along the ventral and dorsal visual streams. Further region-of-interest analyses established that dorsal and ventral regions showed MEG–fMRI correspondence in representations later than early visual cortex. Together, these results provide a novel and comprehensive, spatio-temporally resolved view of the rapid neural dynamics during the first few hundred milliseconds of object vision. They further demonstrate the feasibility of spatially unbiased representational similarity-based fusion of MEG and fMRI, promising new insights into how the brain computes complex cognitive functions. PMID:27235099

Dynamic hyperbolic geometry: building intuition and understanding mediated by a Euclidean model

NASA Astrophysics Data System (ADS)

Moreno-Armella, Luis; Brady, Corey; Elizondo-Ramirez, Rubén

2018-05-01

This paper explores a deep transformation in mathematical epistemology and its consequences for teaching and learning. With the advent of non-Euclidean geometries, direct, iconic correspondences between physical space and the deductive structures of mathematical inquiry were broken. For non-Euclidean ideas even to become thinkable the mathematical community needed to accumulate over twenty centuries of reflection and effort: a precious instance of distributed intelligence at the cultural level. In geometry education after this crisis, relations between intuitions and geometrical reasoning must be established philosophically, rather than taken for granted. One approach seeks intuitive supports only for Euclidean explorations, viewing non-Euclidean inquiry as fundamentally non-intuitive in nature. We argue for moving beyond such an impoverished approach, using dynamic geometry environments to develop new intuitions even in the extremely challenging setting of hyperbolic geometry. Our efforts reverse the typical direction, using formal structures as a source for a new family of intuitions that emerge from exploring a digital model of hyperbolic geometry. This digital model is elaborated within a Euclidean dynamic geometry environment, enabling a conceptual dance that re-configures Euclidean knowledge as a support for building intuitions in hyperbolic space-intuitions based not directly on physical experience but on analogies extending Euclidean concepts.

Paul Natorp and the emergence of anti-psychologism in the nineteenth century.

PubMed

Edgar, Scott

2008-03-01

This paper examines the anti-psychologism of Paul Natorp, a Marburg School Neo-Kantian. It identifies both Natorp's principle argument against psychologism and the views underlying the argument that give it its force. Natorp's argument depends for its success on his view that certain scientific laws constitute the intersubjective content of knowledge. That view in turn depends on Natorp's conception of subjectivity, so it is only against the background of his conception of subjectivity that his reasons for rejecting psychologism make sense. This interpretation of Natorp suggests that attention paid to late nineteenth century theories of subjectivity and philosophy of psychology could improve our understanding of the emergence of anti-psychologism in that period.

Prompt Disappearance and Emergence of Radiation Belt Magnetosonic Waves Induced by Solar Wind Dynamic Pressure Variations

NASA Astrophysics Data System (ADS)

Liu, Nigang; Su, Zhenpeng; Zheng, Huinan; Wang, Yuming; Wang, Shui

2018-01-01

Magnetosonic waves are highly oblique whistler mode emissions transferring energy from the ring current protons to the radiation belt electrons in the inner magnetosphere. Here we present the first report of prompt disappearance and emergence of magnetosonic waves induced by the solar wind dynamic pressure variations. The solar wind dynamic pressure reduction caused the magnetosphere expansion, adiabatically decelerated the ring current protons for the Bernstein mode instability, and produced the prompt disappearance of magnetosonic waves. On the contrary, because of the adiabatic acceleration of the ring current protons by the solar wind dynamic pressure enhancement, magnetosonic waves emerged suddenly. In the absence of impulsive injections of hot protons, magnetosonic waves were observable even only during the time period with the enhanced solar wind dynamic pressure. Our results demonstrate that the solar wind dynamic pressure is an essential parameter for modeling of magnetosonic waves and their effect on the radiation belt electrons.

Active Polymers — Emergent Conformational and Dynamical Properties: A Brief Review

NASA Astrophysics Data System (ADS)

Winkler, Roland G.; Elgeti, Jens; Gompper, Gerhard

2017-10-01

Active matter exhibits a wealth of emerging nonequilibrium behaviours. A paradigmatic example is the interior of cells, where active components, such as the cytoskeleton, are responsible for its structural organization and the dynamics of the various components. Of particular interest are the properties of polymers and filaments. The intimate coupling of thermal and active noise, hydrodynamic interactions, and polymer conformations implies the emergence of novel structural and dynamical features. In this article, we review recent theoretical and simulation developments and results for the structural and dynamical properties of polymers exposed to activity. Two- and three-dimensional filaments are considered propelled by different mechanisms such as active Brownian particles or hydrodynamically-coupled force dipoles.

What Does It Take to Be an Adult in Austria? Views of Adulthood in Austrian Adolescents, Emerging Adults, and Adults

ERIC Educational Resources Information Center

Sirsch, Ulrike; Dreher, Eva; Mayr, Eva; Willinger, Ulrike

2009-01-01

The present study examined the defining features of emerging adulthood, subjects' conceptions of the transition to adulthood, and the perceived adult status in Austria. The sample consisted of 775 subjects (226 adolescents, 317 emerging adults, 232 adults). Results showed that most Austrian emerging adults feel themselves to be between adolescence…

The polymorphisms of the chromatin fiber

NASA Astrophysics Data System (ADS)

Boulé, Jean-Baptiste; Mozziconacci, Julien; Lavelle, Christophe

2015-01-01

In eukaryotes, the genome is packed into chromosomes, each consisting of large polymeric fibers made of DNA bound with proteins (mainly histones) and RNA molecules. The nature and precise 3D organization of this fiber has been a matter of intense speculations and debates. In the emerging picture, the local chromatin state plays a critical role in all fundamental DNA transactions, such as transcriptional control, DNA replication or repair. However, the molecular and structural mechanisms involved remain elusive. The purpose of this review is to give an overview of the tremendous efforts that have been made for almost 40 years to build physiologically relevant models of chromatin structure. The motivation behind building such models was to shift our representation and understanding of DNA transactions from a too simplistic ‘naked DNA’ view to a more realistic ‘coated DNA’ view, as a step towards a better framework in which to interpret mechanistically the control of genetic expression and other DNA metabolic processes. The field has evolved from a speculative point of view towards in vitro biochemistry and in silico modeling, but is still longing for experimental in vivo validations of the proposed structures or even proof of concept experiments demonstrating a clear role of a given structure in a metabolic transaction. The mere existence of a chromatin fiber as a relevant biological entity in vivo has been put into serious questioning. Current research is suggesting a possible reconciliation between theoretical studies and experiments, pointing towards a view where the polymorphic and dynamic nature of the chromatin fiber is essential to support its function in genome metabolism.

Why language really is not a communication system: a cognitive view of language evolution

PubMed Central

Reboul, Anne C.

2015-01-01

While most evolutionary scenarios for language see it as a communication system with consequences on the language-ready brain, there are major difficulties for such a view. First, language has a core combination of features—semanticity, discrete infinity, and decoupling—that makes it unique among communication systems and that raise deep problems for the view that it evolved for communication. Second, extant models of communication systems—the code model of communication (Millikan, 2005) and the ostensive model of communication (Scott-Phillips, 2015) cannot account for language evolution. I propose an alternative view, according to which language first evolved as a cognitive tool, following Fodor’s (1975, 2008) Language of Thought Hypothesis, and was then exapted (externalized) for communication. On this view, a language-ready brain is a brain profoundly reorganized in terms of connectivity, allowing the human conceptual system to emerge, triggering the emergence of syntax. Language as used in communication inherited its core combination of features from the Language of Thought. PMID:26441802

Students' Views about the Problem Based Collaborative Learning Environment Supported by Dynamic Web Technologies

ERIC Educational Resources Information Center

Ünal, Erhan; Çakir, Hasan

2017-01-01

The purpose of this study was to design a problem based collaborative learning environment supported by dynamic web technologies and to examine students' views about this learning environment. The study was designed as a qualitative research. Some 36 students who took an Object Oriented Programming I-II course at the department of computer…

Would Tarzan believe in God? Conditions for the emergence of religious belief.

PubMed

Banerjee, Konika; Bloom, Paul

2013-01-01

Would someone raised without exposure to religious views nonetheless come to believe in the existence of God, an afterlife, and the intentional creation of humans and other animals? Many scholars would answer yes, proposing that universal cognitive biases generate religious ideas anew within each individual mind. Drawing on evidence from developmental psychology, we argue here that the answer is no: children lack spontaneous theistic views and the emergence of religion is crucially dependent on culture. Copyright © 2012 Elsevier Ltd. All rights reserved.

19. DETAIL VIEW OF UPPER EAST WALL CONTROL STATION, SHOWING ...

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

19. DETAIL VIEW OF UPPER EAST WALL CONTROL STATION, SHOWING EMERGENCY BULKHEAD STIFFLEG DERRICK TO RIGHT, LOOKING WEST - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

VIEW OF BUILDING 122 EXAMINATION FACILITIES THAT SUPPORT ROUTINE EMPLOYEE ...

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

VIEW OF BUILDING 122 EXAMINATION FACILITIES THAT SUPPORT ROUTINE EMPLOYEE AND SUBCONTRACTOR PHYSICAL EXAMINATIONS. (10/85) - Rocky Flats Plant, Emergency Medical Services Facility, Southwest corner of Central & Third Avenues, Golden, Jefferson County, CO

Autostereoscopic 3D display system with dynamic fusion of the viewing zone under eye tracking: principles, setup, and evaluation [Invited].

PubMed

Yoon, Ki-Hyuk; Kang, Min-Koo; Lee, Hwasun; Kim, Sung-Kyu

2018-01-01

We study optical technologies for viewer-tracked autostereoscopic 3D display (VTA3D), which provides improved 3D image quality and extended viewing range. In particular, we utilize a technique-the so-called dynamic fusion of viewing zone (DFVZ)-for each 3D optical line to realize image quality equivalent to that achievable at optimal viewing distance, even when a viewer is moving in a depth direction. In addition, we examine quantitative properties of viewing zones provided by the VTA3D system that adopted DFVZ, revealing that the optimal viewing zone can be formed at viewer position. Last, we show that the comfort zone is extended due to DFVZ. This is demonstrated by a viewer's subjective evaluation of the 3D display system that employs both multiview autostereoscopic 3D display and DFVZ.

Transistor analogs of emergent iono-neuronal dynamics.

PubMed

Rachmuth, Guy; Poon, Chi-Sang

2008-06-01

Neuromorphic analog metal-oxide-silicon (MOS) transistor circuits promise compact, low-power, and high-speed emulations of iono-neuronal dynamics orders-of-magnitude faster than digital simulation. However, their inherently limited input voltage dynamic range vs power consumption and silicon die area tradeoffs makes them highly sensitive to transistor mismatch due to fabrication inaccuracy, device noise, and other nonidealities. This limitation precludes robust analog very-large-scale-integration (aVLSI) circuits implementation of emergent iono-neuronal dynamics computations beyond simple spiking with limited ion channel dynamics. Here we present versatile neuromorphic analog building-block circuits that afford near-maximum voltage dynamic range operating within the low-power MOS transistor weak-inversion regime which is ideal for aVLSI implementation or implantable biomimetic device applications. The fabricated microchip allowed robust realization of dynamic iono-neuronal computations such as coincidence detection of presynaptic spikes or pre- and postsynaptic activities. As a critical performance benchmark, the high-speed and highly interactive iono-neuronal simulation capability on-chip enabled our prompt discovery of a minimal model of chaotic pacemaker bursting, an emergent iono-neuronal behavior of fundamental biological significance which has hitherto defied experimental testing or computational exploration via conventional digital or analog simulations. These compact and power-efficient transistor analogs of emergent iono-neuronal dynamics open new avenues for next-generation neuromorphic, neuroprosthetic, and brain-machine interface applications.

On emergence: a neo-psychoanalytic essay on change and science.

PubMed

Whitehead, Clay C

2011-01-01

The neo-psychoanalytic paradigm re-establishes the connection between psychodynamics and evolution. This allows us to transcend the limitations of dualistic metapsychology, and to make seminal contributions to traditional science. The new paradigm employs the concept of emergence, the potential for change in the evolutionary and clinical process. Emergence is described as originating with the Big Bang, but also is reflected at much higher levels, for example, biochemistry, or the capacity of the evolved mind to produce insights in psychotherapy. The constraints of dualistic theories are examined. A neuron-based view of change illustrates the evolution of traditional science as well as the neuron, itself. The new mind paradigm recognizes individual, familial, communitarian, and global reciprocal influences mediated by culture and illustrated by the extended mind and the democratic spirit. Thus both traditional and psychodynamic sciences are undergoing revolutionary changes in their common efforts to better understand the mechanisms of knowledge, relationship and consciousness. The boundaries of the self and the consultation suite are also expanded in this view. Following a survey of invagination, the work is concluded by an application of emergence theory to the creationist controversy and Freud's views of religion.

Streamlining emergent hand and wrist radiography with a modified four-view protocol.

PubMed

Chou, Henry Y; Steenburg, Scott D; Dunkle, Jeffrey W; Gussick, Sean D; Petersen, Matthew J; Kohli, Marc D; Shen, Changyu; Lin, Hongbo

2016-08-01

This study aims to determine whether a modified four-view hand and wrist study performs comparably to the traditional seven views in the evaluation of acute hand and wrist fractures. This retrospective study was approved by the institutional review board with waiver of informed consent. Two hundred forty patients (50 % male; ages 18-92 years) with unilateral three-view hand (posteroanterior, oblique, and lateral) and four-view wrist (posteroanterior, oblique, lateral, and ulnar deviation) radiographs obtained concurrently following trauma were included in this study. Four emergency radiologists interpreted the original seven images, with two radiologists independently evaluating each study. The patients' radiographs were then recombined into four-view series using the three hand images and the ulnar deviated wrist image. These were interpreted by the same radiologists following an 8-week delay. Kappa statistics were generated to measure inter-observer and inter-method agreement. Generalized linear mixed model analysis was performed between the seven- and four-view methods. Of the 480 reports generated in each of the seven- and four-view image sets, 142 (29.6 %) of the seven-view and 126 (26.2 %) of the four-view reports conveyed certain or suspected acute osseous findings. Average inter-observer kappa coefficients were 0.7845 and 0.8261 for the seven- and four-view protocols, respectively. The average inter-method kappa was 0.823. The odds ratio of diagnosing injury using the four-view compared to the seven-view algorithm was 0.69 (CI 0.45-1.06, P = 0.0873). The modified four-view hand and wrist radiographic series produces diagnostic results comparable to the traditional seven views for acute fracture evaluation.

View-invariant object category learning, recognition, and search: how spatial and object attention are coordinated using surface-based attentional shrouds.

PubMed

Fazl, Arash; Grossberg, Stephen; Mingolla, Ennio

2009-02-01

How does the brain learn to recognize an object from multiple viewpoints while scanning a scene with eye movements? How does the brain avoid the problem of erroneously classifying parts of different objects together? How are attention and eye movements intelligently coordinated to facilitate object learning? A neural model provides a unified mechanistic explanation of how spatial and object attention work together to search a scene and learn what is in it. The ARTSCAN model predicts how an object's surface representation generates a form-fitting distribution of spatial attention, or "attentional shroud". All surface representations dynamically compete for spatial attention to form a shroud. The winning shroud persists during active scanning of the object. The shroud maintains sustained activity of an emerging view-invariant category representation while multiple view-specific category representations are learned and are linked through associative learning to the view-invariant object category. The shroud also helps to restrict scanning eye movements to salient features on the attended object. Object attention plays a role in controlling and stabilizing the learning of view-specific object categories. Spatial attention hereby coordinates the deployment of object attention during object category learning. Shroud collapse releases a reset signal that inhibits the active view-invariant category in the What cortical processing stream. Then a new shroud, corresponding to a different object, forms in the Where cortical processing stream, and search using attention shifts and eye movements continues to learn new objects throughout a scene. The model mechanistically clarifies basic properties of attention shifts (engage, move, disengage) and inhibition of return. It simulates human reaction time data about object-based spatial attention shifts, and learns with 98.1% accuracy and a compression of 430 on a letter database whose letters vary in size, position, and orientation. The model provides a powerful framework for unifying many data about spatial and object attention, and their interactions during perception, cognition, and action.

Does a person selectively recall the good or the bad from their personal past? It depends on the recall target and the person's favourability of self-views.

PubMed

Ritchie, Timothy D; Sedikides, Constantine; Skowronski, John J

2017-09-01

In three studies, participants remembered real-life behaviours at Time 1 and attempted to recall them at Time 2. When the recall target was the self, a positivity bias emerged: self-positivity. In Study 3, self-positivity extended to an individual (target) who was liked by the participant, but did it not extend to a disliked target. For this latter target, a negativity bias emerged. For recall targets that were participants' acquaintances, self-positivity in recall was also eliminated in Studies 1 and 3, and a negativity bias in recall emerged in Study 2. Finally, in Study 2 (but not Study 3), the favourability of participants' self-view predicted the magnitude of the self-positivity in self-recall, but it did not predict valence effects in other-recall. Taken together, the results indicate that the link between behaviour valence and recall is moderated by the recall target and the favourability of one's self-view.

Haldane's The causes of evolution and the Modern Synthesis in evolutionary biology.

PubMed

Sarkar, Sahotra

2017-11-01

This paper argues that Haldane's The causes of evolution was the most important founding document in the emergence of the received view of evolutionary theory which is typically referred to as the Modern Synthesis. Whether or not this historical development is characterized as a synthesis (which remains controversial), this paper argues the most important component of the emergence of the received view consisted of showing how the formal rules of Mendelian inheritance are based on (or emerge from) the material basis of heredity established by classical genetics primarily through the experimental work on Drosophila genetics of the Morgan school in the 1910s and 1920s. This is one of the most important achievements of Haldane's book. Thus this paper rejects both (i) the view that the synthesis was a unification of biometry and Mendelism and (ii) the claim that it arose from work primarily done in the late 1930s and 1940s by naturalists rather than theoretical population and classical experimental geneticists.

Emergency department triage: an ethical analysis

PubMed Central

2011-01-01

Background Emergency departments across the globe follow a triage system in order to cope with overcrowding. The intention behind triage is to improve the emergency care and to prioritize cases in terms of clinical urgency. Discussion In emergency department triage, medical care might lead to adverse consequences like delay in providing care, compromise in privacy and confidentiality, poor physician-patient communication, failing to provide the necessary care altogether, or even having to decide whose life to save when not everyone can be saved. These consequences challenge the ethical quality of emergency care. This article provides an ethical analysis of "routine" emergency department triage. The four principles of biomedical ethics - viz. respect for autonomy, beneficence, nonmaleficence and justice provide the starting point and help us to identify the ethical challenges of emergency department triage. However, they do not offer a comprehensive ethical view. To address the ethical issues of emergency department triage from a more comprehensive ethical view, the care ethics perspective offers additional insights. Summary We integrate the results from the analysis using four principles of biomedical ethics into care ethics perspective on triage and propose an integrated clinically and ethically based framework of emergency department triage planning, as seen from a comprehensive ethics perspective that incorporates both the principles-based and care-oriented approach. PMID:21982119

4. VIEW SOUTHWEST COMPONENTS TEST LAB TEST BAY DETAIL SHOWING ...

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

4. VIEW SOUTHWEST COMPONENTS TEST LAB TEST BAY DETAIL SHOWING EMERGENCY SHOWER, AND EYEWASH, AND OBSERVATION WINDOW. STORAGE TANKS ON ROOF. - Marshall Space Flight Center, East Test Area, Components Test Laboratory, Huntsville, Madison County, AL

Young Children's Self-Generated Object Views and Object Recognition

ERIC Educational Resources Information Center

James, Karin H.; Jones, Susan S.; Smith, Linda B.; Swain, Shelley N.

2014-01-01

Two important and related developments in children between 18 and 24 months of age are the rapid expansion of object name vocabularies and the emergence of an ability to recognize objects from sparse representations of their geometric shapes. In the same period, children also begin to show a preference for planar views (i.e., views of objects held…

Emergent phases and critical behavior in a non-Markovian open quantum system

NASA Astrophysics Data System (ADS)

Cheung, H. F. H.; Patil, Y. S.; Vengalattore, M.

2018-05-01

Open quantum systems exhibit a range of novel out-of-equilibrium behavior due to the interplay between coherent quantum dynamics and dissipation. Of particular interest in these systems are driven, dissipative transitions, the emergence of dynamical phases with novel broken symmetries, and critical behavior that lies beyond the conventional paradigm of Landau-Ginzburg phenomenology. Here, we consider a parametrically driven two-mode system in the presence of non-Markovian system-reservoir interactions. We show that the non-Markovian dynamics modifies the phase diagram of this system, resulting in the emergence of a broken symmetry phase in a universality class that has no counterpart in the corresponding Markovian system. This emergent phase is accompanied by enhanced two-mode entanglement that remains robust at finite temperatures. Such reservoir-engineered dynamical phases can potentially shed light on universal aspects of dynamical phase transitions in a wide range of nonequilibrium systems, and aid in the development of techniques for the robust generation of entanglement and quantum correlations at finite temperatures with potential applications to quantum control, state preparation, and metrology.

Dynamically downscaling predictions for deciduous tree leaf emergence in California under current and future climate.

PubMed

Medvigy, David; Kim, Seung Hee; Kim, Jinwon; Kafatos, Menas C

2016-07-01

Models that predict the timing of deciduous tree leaf emergence are typically very sensitive to temperature. However, many temperature data products, including those from climate models, have been developed at a very coarse spatial resolution. Such coarse-resolution temperature products can lead to highly biased predictions of leaf emergence. This study investigates how dynamical downscaling of climate models impacts simulations of deciduous tree leaf emergence in California. Models for leaf emergence are forced with temperatures simulated by a general circulation model (GCM) at ~200-km resolution for 1981-2000 and 2031-2050 conditions. GCM simulations are then dynamically downscaled to 32- and 8-km resolution, and leaf emergence is again simulated. For 1981-2000, the regional average leaf emergence date is 30.8 days earlier in 32-km simulations than in ~200-km simulations. Differences between the 32 and 8 km simulations are small and mostly local. The impact of downscaling from 200 to 8 km is ~15 % smaller in 2031-2050 than in 1981-2000, indicating that the impacts of downscaling are unlikely to be stationary.

Semantics and pragmatics.

PubMed

McNally, Louise

2013-05-01

The fields of semantics and pragmatics are devoted to the study of conventionalized and context- or use-dependent aspects of natural language meaning, respectively. The complexity of human language as a semiotic system has led to considerable debate about how the semantics/pragmatics distinction should be drawn, if at all. This debate largely reflects contrasting views of meaning as a property of linguistic expressions versus something that speakers do. The fact that both views of meaning are essential to a complete understanding of language has led to a variety of efforts over the last 40 years to develop better integrated and more comprehensive theories of language use and interpretation. The most important advances have included the adaptation of propositional analyses of declarative sentences to interrogative, imperative and exclamative forms; the emergence of dynamic, game theoretic, and multi-dimensional theories of meaning; and the development of various techniques for incorporating context-dependent aspects of content into representations of context-invariant content with the goal of handling phenomena such as vagueness resolution, metaphor, and metonymy. WIREs Cogn Sci 2013, 4:285-297. doi: 10.1002/wcs.1227 For further resources related to this article, please visit the WIREs website. The authors declare no conflict of interest. Copyright © 2013 John Wiley & Sons, Ltd.

Does the Dynamic Indicators of Basic Early Literacy Skills Next Assessment Take a "Simple View" of Reading?

ERIC Educational Resources Information Center

Munger, Kristen A.; LoFaro, Stephen A.; Kawryga, Erin A.; Sovocool, Elizabeth A.; Medina, Siani Y.

2014-01-01

This study involved examination of the validity evidence of the Dynamic Indicators of Basic Early Literacy Skills-Next Edition (DIBELS Next) for a sample of 85 third-and fifth-grade students, in reference to the "simple view" of reading. Tests administered included DIBELS Next, Peabody Picture Vocabulary Test-IV (PPVT-IV), Group Reading…

14-Month-Old Infants Form Novel Word-Spatial Relation Associations

ERIC Educational Resources Information Center

Casasola, Marianella; Wilbourn, Makeba Parramore

2004-01-01

This study explored 14-month-old infants' ability to form novel word-spatial relation associations. During habituation, infants heard 1 novel word (e.g., "teek") while viewing dynamic containment events (i.e., Big Bird placed in a box) and, on other habituation trials, a second novel word (e.g., "blick") while viewing dynamic support events (i.e.,…

The Impact of Dynamic Assessment: An Exploration of the Views of Children, Parents and Teachers

ERIC Educational Resources Information Center

Lawrence, Nicola; Cahill, Sharon

2014-01-01

A qualitative research project was carried out to explore the views of children with special educational needs, their parents and teachers about one aspect of educational psychology practice: the dynamic assessment of cognitive skills. The research was carried out in a highly diverse and inclusive borough in East London, by Nicola Lawrence from…

Views of Pre-Service Teachers Following Teaching Experience on Use of Dynamic Geometry Software

ERIC Educational Resources Information Center

Günes, Kardelen; Tapan-Broutin, Menekse Seden

2017-01-01

The study aims to determine the views of final-year pre-service mathematics teachers towards their experience of the use of dynamic geometry software in teaching, following the implementation processes that they carried out when using this software in a real classroom environment. The study was designed as a case study, which is one of the…

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

PubMed

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

2011-01-01

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

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

PubMed Central

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

2011-01-01

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

Using Generational Theory to Rethink Teaching in Higher Education

ERIC Educational Resources Information Center

Buskirk-Cohen, Allison A.; Duncan, Tisha A.; Levicoff, Margaret

2016-01-01

This paper reviews the literature on emerging adulthood with a focus on the implications of generational theory on teaching and learning in higher education. During the past 15 years, researchers have described personality traits, attitudes, and behaviors of emerging adults. Two very different views have emerged: one that is prosocial, citing…

Background history and cosmic perturbations for a general system of self-conserved dynamical dark energy and matter

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

Gómez-Valent, Adrià; Karimkhani, Elahe; Solà, Joan, E-mail: adriagova@ecm.ub.edu, E-mail: e.karimkhani91@basu.ac.ir, E-mail: sola@ecm.ub.edu

We determine the Hubble expansion and the general cosmic perturbation equations for a general system consisting of self-conserved matter, ρ{sub m}, and self-conserved dark energy (DE), ρ{sub D}. While at the background level the two components are non-interacting, they do interact at the perturbations level. We show that the coupled system of matter and DE perturbations can be transformed into a single, third order, matter perturbation equation, which reduces to the (derivative of the) standard one in the case that the DE is just a cosmological constant. As a nontrivial application we analyze a class of dynamical models whose DEmore » density ρ{sub D}(H) consists of a constant term, C{sub 0}, and a series of powers of the Hubble rate. These models were previously analyzed from the point of view of dynamical vacuum models, but here we treat them as self-conserved DE models with a dynamical equation of state. We fit them to the wealth of expansion history and linear structure formation data and compare their fit quality with that of the concordance ΛCDM model. Those with C{sub 0}=0 include the so-called ''entropic-force'' and ''QCD-ghost'' DE models, as well as the pure linear model ρ{sub D}∼H, all of which appear strongly disfavored. The models with C{sub 0}≠0 , in contrast, emerge as promising dynamical DE candidates whose phenomenological performance is highly competitive with the rigid Λ-term inherent to the ΛCDM.« less

Endocannabinoid signaling and memory dynamics: A synaptic perspective.

PubMed

Drumond, Ana; Madeira, Natália; Fonseca, Rosalina

2017-02-01

Memory acquisition is a key brain feature in which our human nature relies on. Memories evolve over time. Initially after learning, memories are labile and sensitive to disruption by the interference of concurrent events. Later on, after consolidation, memories are resistant to disruption. However, reactivation of previously consolidated memories renders them again in an unstable state and therefore susceptible to perturbation. Additionally, and depending on the characteristics of the stimuli, a parallel process may be initiated which ultimately leads to the extinction of the previously acquired response. This dynamic aspect of memory maintenance opens the possibility for an updating of previously acquired memories but it also creates several conceptual challenges. What is the time window for memory updating? What determines whether reconsolidation or extinction is triggered? In this review, we tried to re-examine the relationship between consolidation, reconsolidation and extinction, aiming for a unifying view of memory dynamics. Since cellular models of memory share common principles, we present the evidence that similar rules apply to the maintenance of synaptic plasticity. Recently, a new function of the endocannabinoid (eCB) signaling system has been described for associative forms of synaptic plasticity in amygdala synapses. The eCB system has emerged as a key modulator of memory dynamics by adjusting the outcome to stimuli intensity. We propose a key function of eCB in discriminative forms of learning by restricting associative plasticity in amygdala synapses. Since many neuropsychiatric disorders are associated with a dysregulation in memory dynamics, understanding the rules underlying memory maintenance paves the path to better clinical interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

Swarm Intelligence for Urban Dynamics Modelling

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

Ghnemat, Rawan; Bertelle, Cyrille; Duchamp, Gerard H. E.

2009-04-16

In this paper, we propose swarm intelligence algorithms to deal with dynamical and spatial organization emergence. The goal is to model and simulate the developement of spatial centers using multi-criteria. We combine a decentralized approach based on emergent clustering mixed with spatial constraints or attractions. We propose an extension of the ant nest building algorithm with multi-center and adaptive process. Typically, this model is suitable to analyse and simulate urban dynamics like gentrification or the dynamics of the cultural equipment in urban area.

Swarm Intelligence for Urban Dynamics Modelling

NASA Astrophysics Data System (ADS)

Ghnemat, Rawan; Bertelle, Cyrille; Duchamp, Gérard H. E.

2009-04-01

In this paper, we propose swarm intelligence algorithms to deal with dynamical and spatial organization emergence. The goal is to model and simulate the developement of spatial centers using multi-criteria. We combine a decentralized approach based on emergent clustering mixed with spatial constraints or attractions. We propose an extension of the ant nest building algorithm with multi-center and adaptive process. Typically, this model is suitable to analyse and simulate urban dynamics like gentrification or the dynamics of the cultural equipment in urban area.

Validating Prehistoric and Current Social Phenomena Upon the Landscape of the Peten, Guatemala

NASA Technical Reports Server (NTRS)

Sever, Thomas L.

1997-01-01

The Peten, once inhabited by a population of several million before the collapse of the ancient Maya in the 10th and 11th centuries, is being repopulated toward its former demographic peak. Environmental dynamics, however, impose severe constraints to further development. Current practices in subsistence, commercial agriculture, and cattle raising are causing rapid deforestation on a scale that can only result in soil loss and regional degradation. In view of the current deforestation trends, the question emerges as to how millions of ancient Maya lived successfully in the area for centuries when relatively fewer occupants today threaten the sustainability of the landscape with current agricultural practices. The use of remote sensing technology is a cost-effective methodology for addressing issues in Maya archeology as well as monitoring the environmental impacts being experienced by the current population.

Transcription and Recombination: When RNA Meets DNA

PubMed Central

Aguilera, Andrés; Gaillard, Hélène

2014-01-01

A particularly relevant phenomenon in cell physiology and proliferation is the fact that spontaneous mitotic recombination is strongly enhanced by transcription. The most accepted view is that transcription increases the occurrence of double-strand breaks and/or single-stranded DNA gaps that are repaired by recombination. Most breaks would arise as a consequence of the impact that transcription has on replication fork progression, provoking its stalling and/or breakage. Here, we discuss the mechanisms responsible for the cross talk between transcription and recombination, with emphasis on (1) the transcription–replication conflicts as the main source of recombinogenic DNA breaks, and (2) the formation of cotranscriptional R-loops as a major cause of such breaks. The new emerging questions and perspectives are discussed on the basis of the interference between transcription and replication, as well as the way RNA influences genome dynamics. PMID:25085910

The impact of supercomputers on experimentation: A view from a national laboratory

NASA Technical Reports Server (NTRS)

Peterson, V. L.; Arnold, J. O.

1985-01-01

The relative roles of large scale scientific computers and physical experiments in several science and engineering disciplines are discussed. Increasing dependence on computers is shown to be motivated both by the rapid growth in computer speed and memory, which permits accurate numerical simulation of complex physical phenomena, and by the rapid reduction in the cost of performing a calculation, which makes computation an increasingly attractive complement to experimentation. Computer speed and memory requirements are presented for selected areas of such disciplines as fluid dynamics, aerodynamics, aerothermodynamics, chemistry, atmospheric sciences, astronomy, and astrophysics, together with some examples of the complementary nature of computation and experiment. Finally, the impact of the emerging role of computers in the technical disciplines is discussed in terms of both the requirements for experimentation and the attainment of previously inaccessible information on physical processes.

Microscopic description of orbital-selective spin ordering in BaMn2As2

NASA Astrophysics Data System (ADS)

Craco, L.; Carara, S. S.

2018-05-01

Using generalized gradient approximation+dynamical mean-field theory, we provide a microscopic description of orbital-selective spin ordering in the tetragonal manganese pnictide BaMn2As2 . We demonstrate the coexistence of local moments and small band-gap electronic states in the parent compound. We also explore the role played by electron/hole doping, showing that the Mott insulating state is rather robust to small removal of electron charge carriers similar to cuprate oxide superconductors. Good qualitative accord between theory and angle-resolved photoemission as well as electrical transport provides support to our view of orbital-selective spin ordering in BaMn2As2 . Our proposal is expected to be an important step to understanding the emergent correlated electronic structure of materials with persisting ordered localized moments coexisting with Coulomb reconstructed nonmagnetic electronic states.

Working in the borderland: early relational trauma and Fordham's analysis of 'K'.

PubMed

West, Marcus

2016-02-01

This paper outlines a view of early relational trauma as underlying borderline states of mind, and argues that Knox's paper on internal working models and the complex provides a basis for understanding such states of mind. The author argues that in addition to internal working models, the complex also embodies and contains primitive defences of the core self. He outlines how these apply on the objective, subjective, transference and archetypal levels, and in direct and reversed forms and applies this to the account of Fordham's analysis of his patient 'K', which ended in impasse. The paper explores the dynamic that emerged in that analysis and suggests that it could be helpfully accounted for in terms of the co-construction and re-construction of early relational trauma in the analytic relationship. © 2016, The Society of Analytical Psychology.

Designing Isoform-selective Inhibitors Against Classical HDACs for Effective Anticancer Therapy: Insight and Perspectives from In Silico.

PubMed

Ganai, Shabir Ahmad

2018-01-01

Histone deacetylase inhibitors, the small molecules modulating the biological activity of histone deacetylases are emerging as potent chemotherapeutic agents. Despite their considerable therapeutic benefits in disease models, the lack of isoform specificity culminates in debilitating off target effects, raising serious concerns regarding their applicability. This emphasizes the pressing and unmet medical need of designing isoform selective inhibitors for safe and effective anticancer therapy. Keeping these grim facts in view, the current article sheds light on structural basis of off-targeting. Furthermore, the article discusses extensively the role of in silico strategies such as Molecular Docking, Molecular Dynamics Simulation and Energetically-optimized structure based pharmacophore approach in designing on-target inhibitors against classical HDACs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Emergence of fractal scaling in complex networks

NASA Astrophysics Data System (ADS)

Wei, Zong-Wen; Wang, Bing-Hong

2016-09-01

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

VIEW OF EAST TEST SITE FROM TOP OF STATIC TEST ...

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

VIEW OF EAST TEST SITE FROM TOP OF STATIC TEST TOWER VIEW INCLUDES STRUCTURAL DYNAMICS TEST STAND COLD CALIBRATION TEST STAND AND COMPONENTS TEST LAB. - Marshall Space Flight Center, East Test Area, Dodd Road, Huntsville, Madison County, AL

Repercussion of geometric and dynamic constraints on the 3D rendering quality in structurally adaptive multi-view shooting systems

NASA Astrophysics Data System (ADS)

Ali-Bey, Mohamed; Moughamir, Saïd; Manamanni, Noureddine

2011-12-01

in this paper a simulator of a multi-view shooting system with parallel optical axes and structurally variable configuration is proposed. The considered system is dedicated to the production of 3D contents for auto-stereoscopic visualization. The global shooting/viewing geometrical process, which is the kernel of this shooting system, is detailed and the different viewing, transformation and capture parameters are then defined. An appropriate perspective projection model is afterward derived to work out a simulator. At first, this latter is used to validate the global geometrical process in the case of a static configuration. Next, the simulator is used to show the limitations of a static configuration of this shooting system type by considering the case of dynamic scenes and then a dynamic scheme is achieved to allow a correct capture of this kind of scenes. After that, the effect of the different geometrical capture parameters on the 3D rendering quality and the necessity or not of their adaptation is studied. Finally, some dynamic effects and their repercussions on the 3D rendering quality of dynamic scenes are analyzed using error images and some image quantization tools. Simulation and experimental results are presented throughout this paper to illustrate the different studied points. Some conclusions and perspectives end the paper. [Figure not available: see fulltext.

Dynamic Organization of Hierarchical Memories

PubMed Central

Kurikawa, Tomoki; Kaneko, Kunihiko

2016-01-01

In the brain, external objects are categorized in a hierarchical way. Although it is widely accepted that objects are represented as static attractors in neural state space, this view does not take account interaction between intrinsic neural dynamics and external input, which is essential to understand how neural system responds to inputs. Indeed, structured spontaneous neural activity without external inputs is known to exist, and its relationship with evoked activities is discussed. Then, how categorical representation is embedded into the spontaneous and evoked activities has to be uncovered. To address this question, we studied bifurcation process with increasing input after hierarchically clustered associative memories are learned. We found a “dynamic categorization”; neural activity without input wanders globally over the state space including all memories. Then with the increase of input strength, diffuse representation of higher category exhibits transitions to focused ones specific to each object. The hierarchy of memories is embedded in the transition probability from one memory to another during the spontaneous dynamics. With increased input strength, neural activity wanders over a narrower state space including a smaller set of memories, showing more specific category or memory corresponding to the applied input. Moreover, such coarse-to-fine transitions are also observed temporally during transient process under constant input, which agrees with experimental findings in the temporal cortex. These results suggest the hierarchy emerging through interaction with an external input underlies hierarchy during transient process, as well as in the spontaneous activity. PMID:27618549

Clustering determines the dynamics of complex contagions in multiplex networks

NASA Astrophysics Data System (ADS)

Zhuang, Yong; Arenas, Alex; Yaǧan, Osman

2017-01-01

We present the mathematical analysis of generalized complex contagions in a class of clustered multiplex networks. The model is intended to understand spread of influence, or any other spreading process implying a threshold dynamics, in setups of interconnected networks with significant clustering. The contagion is assumed to be general enough to account for a content-dependent linear threshold model, where each link type has a different weight (for spreading influence) that may depend on the content (e.g., product, rumor, political view) that is being spread. Using the generating functions formalism, we determine the conditions, probability, and expected size of the emergent global cascades. This analysis provides a generalization of previous approaches and is especially useful in problems related to spreading and percolation. The results present nontrivial dependencies between the clustering coefficient of the networks and its average degree. In particular, several phase transitions are shown to occur depending on these descriptors. Generally speaking, our findings reveal that increasing clustering decreases the probability of having global cascades and their size, however, this tendency changes with the average degree. There exists a certain average degree from which on clustering favors the probability and size of the contagion. By comparing the dynamics of complex contagions over multiplex networks and their monoplex projections, we demonstrate that ignoring link types and aggregating network layers may lead to inaccurate conclusions about contagion dynamics, particularly when the correlation of degrees between layers is high.

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

Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter, E-mail: khan@ari.uni-heidelberg.de, E-mail: k.holley@vanderbilt.edu

Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC 1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the largemore » SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC 1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production.« less

The economic role of the Emergency Department in the health care continuum: applying Michael Porter's five forces model to Emergency Medicine.

PubMed

Pines, Jesse M

2006-05-01

Emergency Medicine plays a vital role in the health care continuum in the United States. Michael Porters' five forces model of industry analysis provides an insight into the economics of emergency care by showing how the forces of supplier power, buyer power, threat of substitution, barriers to entry, and internal rivalry affect Emergency Medicine. Illustrating these relationships provides a view into the complexities of the emergency care industry and offers opportunities for Emergency Departments, groups of physicians, and the individual emergency physician to maximize the relationship with other market players.

Respondents, Operants, and Emergents: Toward an Integrated Perspective on Behavior

NASA Technical Reports Server (NTRS)

Rumbaugh, Daune M.; Washburn, David A.; Hillix, William A.

1996-01-01

A triarchic organization of behavior, building on Skinner's description of respondents and operants, is proposed by introducing a third class of behavior called 'emergents.' Emergents are new responses, never specifically reinforced, that require operations more complex than association. Some of these operations occur naturally only in animals above a minimum level of brain complexity, and are developed in an interaction between treatment and organismic variables. (Here complexity is defined in terms of relative levels of hierarchical integration made possible both by the amount of brain, afforded both by brain-body allometric relationships and by encephalization, and, also, the elaboration of dendritic and synaptic connections within the cortex and connections between various parts/regions of the brain.) Examples of emergents are discussed to advance this triarchic view, of behavior. The prime example is language. This triarchic view reflects both the common goals and the cumulative nature of psychological science.

Zone of Proximal Development (ZPD) as an Emergent System: A Dynamic Systems Theory Perspective.

PubMed

Karimi-Aghdam, Saeed

2017-03-01

This paper sets out to present a novel construal of one of the notions of Vygotskian cultural-historical theory viz., zone of proximal development (ZPD) drawing upon dynamic systems theory. The principal thesis maintains that ZDP is an emergent and dynamic system which is engendered by a dialectical concatenation of psychogenesic and sociogenesic facets of human development over time. It is reasoned that Vygotskian cultural-historical theory of human development, by invoking dialectical logic, has transcended Cartesian substance dualism and in turn has proffered a monistic and process-anchored ontology for emerging becoming of human consciousness. Likewise, it is contended that dynamic systems theory, having assumed fluent flux of reality with a capital R as its ontological axiom, entails a consilience of cognitive and contextual conceptual schemes to describe, explain, and optimize human development. The paper concludes by drawing some interpretive conclusions in regard to ZPD from dynamic systems theory perspective.

The dynamics of insight: mathematical discovery as a phase transition.

PubMed

Stephen, Damian G; Boncoddo, Rebecca A; Magnuson, James S; Dixon, James A

2009-12-01

In recent work in cognitive science, it has been proposed that cognition is a self-organizing, dynamical system. However, capturing the real-time dynamics of cognition has been a formidable challenge. Furthermore, it has been unclear whether dynamics could effectively address the emergence of abstract concepts (e.g., language, mathematics). Here, we provide evidence that a quintessentially cognitive phenomenon-the spontaneous discovery of a mathematical relation-emerges through self-organization. Participants solved a series of gear-system problems while we tracked their eye movements. They initially solved the problems by manually simulating the forces of the gears but then spontaneously discovered a mathematical solution. We show that the discovery of the mathematical relation was predicted by changes in entropy and changes in power-law behavior, two hallmarks of phase transitions. Thus, the present study demonstrates the emergence of higher order cognitive phenomena through the nonlinear dynamics of self-organization.

Cognitive control: componential and yet emergent.

PubMed

Juvina, Ion

2011-04-01

In this commentary, I will argue that the componential and emergent views of cognitive control as defined by Cooper (2010) do not necessarily oppose each other, and I will try to make a case for their interdependence. First, I will use the construct of cognitive inhibition-one of the main componential control functions mentioned in the target articles-to illustrate my line of reasoning. Then, I will comment on how some of the target articles, each from a different perspective, bring arguments in favor of this integrative view. Copyright © 2011 Cognitive Science Society, Inc.

Mirror Symmetry Breaking by Chirality Synchronisation in Liquids and Liquid Crystals of Achiral Molecules.

PubMed

Tschierske, Carsten; Ungar, Goran

2016-01-04

Spontaneous mirror symmetry breaking is an efficient way to obtain homogeneously chiral agents, pharmaceutical ingredients and materials. It is also in the focus of the discussion around the emergence of uniform chirality in biological systems. Tremendous progress has been made by symmetry breaking during crystallisation from supercooled melts or supersaturates solutions and by self-assembly on solid surfaces and in other highly ordered structures. However, recent observations of spontaneous mirror symmetry breaking in liquids and liquid crystals indicate that it is not limited to the well-ordered solid state. Herein, progress in the understanding of a new dynamic mode of symmetry breaking, based on chirality synchronisation of transiently chiral molecules in isotropic liquids and in bicontinuous cubic, columnar, smectic and nematic liquid crystalline phases is discussed. This process leads to spontaneous deracemisation in the liquid state under thermodynamic control, giving rise to long-term stable symmetry-broken fluids, even at high temperatures. These fluids form conglomerates that are capable of extraordinary strong chirality amplification, eventually leading to homochirality and providing a new view on the discussion of emergence of uniform chirality in prebiotic systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

14. DETAIL VIEW OF SERVICE BRIDGE, SHOWING TRAVELLING CRANE AND ...

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

14. DETAIL VIEW OF SERVICE BRIDGE, SHOWING TRAVELLING CRANE AND TAINTER GATE PIER WITH RECESSES FOR EMERGENCY BULKHEADS AND BULKHEAD DOGGING DEVICES, LOOKING NORTHEAST - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

The dynamics of categorization: Unraveling rapid categorization.

PubMed

Mack, Michael L; Palmeri, Thomas J

2015-06-01

We explore a puzzle of visual object categorization: Under normal viewing conditions, you spot something as a dog fastest, but at a glance, you spot it faster as an animal. During speeded category verification, a classic basic-level advantage is commonly observed (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976), with categorization as a dog faster than as an animal (superordinate) or Golden Retriever (subordinate). A different story emerges during ultra-rapid categorization with limited exposure duration (<30 ms), with superordinate categorization faster than basic or subordinate categorization (Thorpe, Fize, & Marlot, 1996). These two widely cited findings paint contrary theoretical pictures about the time course of categorization, yet no previous study has investigated them together. We systematically examined two experimental factors that could explain the qualitative difference in categorization across the two paradigms: exposure duration and category trial context. Mapping out the time course of object categorization by manipulating exposure duration and the timing of a post-stimulus mask revealed that brief exposure durations favor superordinate-level categorization, but with more time a basic-level advantage emerges. However, these advantages were modulated by category trial context. With randomized target categories, the superordinate advantage was eliminated; and with only four repetitions of superordinate categorization within an otherwise randomized context, the basic-level advantage was eliminated. Contrary to theoretical accounts that dictate a fixed priority for certain levels of abstraction in visual processing and access to semantic knowledge, the dynamics of object categorization are flexible, depending jointly on the level of abstraction, time for perceptual encoding, and category context. (c) 2015 APA, all rights reserved).

THE DYNAMICS OF CATEGORIZATION: UNRAVELING RAPID CATEGORIZATION

PubMed Central

Mack, Michael L.; Palmeri, Thomas J.

2015-01-01

We explore a puzzle of visual object categorization: Under normal viewing conditions, you spot something as a dog fastest, but at a glance, you spot it faster as an animal. During speeded category verification, a classic basic-level advantage is commonly observed (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976), with categorization as a dog faster than as an animal (superordinate) or Golden Retriever (subordinate). A different story emerges during ultra-rapid categorization with limited exposure duration (<30ms), with superordinate categorization faster than basic or subordinate categorization (Thorpe, Fize, & Marlot, 1996). These two widely cited findings paint contrary theoretical pictures about the time course of object categorization, yet no study has previously investigated them together. Over five experiments, we systematically examined two experimental factors that could explain the qualitative difference in categorization across the two paradigms: exposure duration and category trial context. Mapping out the time course of object categorization by manipulating exposure duration and the timing of a post-stimulus mask revealed that brief exposure durations favor superordinate-level categorization, but with more time a basic-level advantage emerges. But this superordinate advantage was modulated significantly by target category trial context. With randomized target categories, the superordinate advantage was eliminated; and with “blocks” of only four repetitions of superordinate categorization within an otherwise randomized context, the advantage for the basic-level was eliminated. Contrary to some theoretical accounts that dictate a fixed priority for certain levels of abstraction in visual processing and access to semantic knowledge, the dynamics of object categorization are flexible, depending jointly on the level of abstraction, time for perceptual encoding, and category context. PMID:25938178

Multi-Satellite Scheduling Approach for Dynamic Areal Tasks Triggered by Emergent Disasters

NASA Astrophysics Data System (ADS)

Niu, X. N.; Zhai, X. J.; Tang, H.; Wu, L. X.

2016-06-01

The process of satellite mission scheduling, which plays a significant role in rapid response to emergent disasters, e.g. earthquake, is used to allocate the observation resources and execution time to a series of imaging tasks by maximizing one or more objectives while satisfying certain given constraints. In practice, the information obtained of disaster situation changes dynamically, which accordingly leads to the dynamic imaging requirement of users. We propose a satellite scheduling model to address dynamic imaging tasks triggered by emergent disasters. The goal of proposed model is to meet the emergency response requirements so as to make an imaging plan to acquire rapid and effective information of affected area. In the model, the reward of the schedule is maximized. To solve the model, we firstly present a dynamic segmenting algorithm to partition area targets. Then the dynamic heuristic algorithm embedding in a greedy criterion is designed to obtain the optimal solution. To evaluate the model, we conduct experimental simulations in the scene of Wenchuan Earthquake. The results show that the simulated imaging plan can schedule satellites to observe a wider scope of target area. We conclude that our satellite scheduling model can optimize the usage of satellite resources so as to obtain images in disaster response in a more timely and efficient manner.

Comets as Messengers from the Early Solar System - Emerging Insights on Delivery of Water, Nitriles, and Organics to Earth

NASA Technical Reports Server (NTRS)

Mumma, Michael J.; Charnley, Steven B.

2012-01-01

The question of exogenous delivery of water and organics to Earth and other young planets is of critical importance for understanding the origin of Earth's volatiles, and for assessing the possible existence of exo-planets similar to Earth. Viewed from a cosmic perspective, Earth is a dry planet, yet its oceans are enriched in deuterium by a large factor relative to nebular hydrogen and analogous isotopic enrichments in atmospheric nitrogen and noble gases are also seen. Why is this so? What are the implications for Mars? For icy Worlds in our Planetary System? For the existence of Earth-like exoplanets? An exogenous (vs. outgassed) origin for Earth's atmosphere is implied, and intense debate on the relative contributions of comets and asteroids continues - renewed by fresh models for dynamical transport in the protoplanetary disk, by revelations on the nature and diversity of volatile and rocky material within comets, and by the discovery of ocean-like water in a comet from the Kuiper Belt (cf., Mumma & Charnley 2011). Assessing the creation of conditions favorable to the emergence and sustenance of life depends critically on knowledge of the nature of the impacting bodies. Active comets have long been grouped according to their orbital properties, and this has proven useful for identifying the reservoir from which a given comet emerged (OC, KB) (Levison 1996). However, it is now clear that icy bodies were scattered into each reservoir from a range of nebular distances, and the comet populations in today's reservoirs thus share origins that are (in part) common. Comets from the Oort Cloud and Kuiper Disk reservoirs should have diverse composition, resulting from strong gradients in temperature and chemistry in the proto-planetary disk, coupled with dynamical models of early radial transport and mixing with later dispersion of the final cometary nuclei into the long-term storage reservoirs. The inclusion of material from the natal interstellar cloud is probable, for comets formed in the outer solar system.

Evaluating HDR photos using Web 2.0 technology

NASA Astrophysics Data System (ADS)

Qiu, Guoping; Mei, Yujie; Duan, Jiang

2011-01-01

High dynamic range (HDR) photography is an emerging technology that has the potential to dramatically enhance the visual quality and realism of digital photos. One of the key technical challenges of HDR photography is displaying HDR photos on conventional devices through tone mapping or dynamic range compression. Although many different tone mapping techniques have been developed in recent years, evaluating tone mapping operators prove to be extremely difficult. Web2.0, social media and crowd-sourcing are emerging Internet technologies which can be harnessed to harvest the brain power of the mass to solve difficult problems in science, engineering and businesses. Paired comparison is used in the scientific study of preferences and attitudes and has been shown to be capable of obtaining an interval-scale ordering of items along a psychometric dimension such as preference or importance. In this paper, we exploit these technologies for evaluating HDR tone mapping algorithms. We have developed a Web2.0 style system that enables Internet users from anywhere to evaluate tone mapped HDR photos at any time. We adopt a simple paired comparison protocol, Internet users are presented a pair of tone mapped images and are simply asked to select the one that they think is better or click a "no difference" button. These user inputs are collected in the web server and analyzed by a rank aggregation algorithm which ranks the tone mapped photos according to the votes they received. We present experimental results which demonstrate that the emerging Internet technologies can be exploited as a new paradigm for evaluating HDR tone mapping algorithms. The advantages of this approach include the potential of collecting large user inputs under a variety of viewing environments rather than limited user participation under controlled laboratory environments thus enabling more robust and reliable quality assessment. We also present data analysis to correlate user generated qualitative indices with quantitative image statistics which may provide useful guidance for developing better tone mapping operators.

Emergent gauge fields and their nonperturbative effects in correlated electrons

NASA Astrophysics Data System (ADS)

Kim, Ki-Seok; Tanaka, Akihiro

2015-06-01

The history of modern condensed matter physics may be regarded as the competition and reconciliation between Stoner’s and Anderson’s physical pictures, where the former is based on momentum-space descriptions focusing on long wave-length fluctuations while the latter is based on real-space physics emphasizing emergent localized excitations. In particular, these two view points compete with each other in various nonperturbative phenomena, which range from the problem of high Tc superconductivity, quantum spin liquids in organic materials and frustrated spin systems, heavy-fermion quantum criticality, metal-insulator transitions in correlated electron systems such as doped silicons and two-dimensional electron systems, the fractional quantum Hall effect, to the recently discussed Fe-based superconductors. An approach to reconcile these competing frameworks is to introduce topologically nontrivial excitations into the Stoner’s description, which appear to be localized in either space or time and sometimes both, where scattering between itinerant electrons and topological excitations such as skyrmions, vortices, various forms of instantons, emergent magnetic monopoles, and etc. may catch nonperturbative local physics beyond the Stoner’s paradigm. In this review paper, we discuss nonperturbative effects of topological excitations on dynamics of correlated electrons. First, we focus on the problem of scattering between itinerant fermions and topological excitations in antiferromagnetic doped Mott insulators, expected to be relevant for the pseudogap phase of high Tc cuprates. We propose that nonperturbative effects of topological excitations can be incorporated within the perturbative framework, where an enhanced global symmetry with a topological term plays an essential role. In the second part, we go on to discuss the subject of symmetry protected topological states in a largely similar light. While we do not introduce itinerant fermions here, the nonperturbative dynamics of topological excitations is again seen to be crucial in classifying topologically nontrivial gapped systems. We point to some hidden links between several effective field theories with topological terms, starting with one-dimensional physics, and subsequently finding natural generalizations to higher dimensions.

Emergent Gauge Fields and Their Nonperturbative Effects in Correlated Electrons

NASA Astrophysics Data System (ADS)

Kim, Ki-Seok; Tanaka, Akihiro

The history of modern condensed matter physics may be regarded as the competition and reconciliation between Stoner's and Anderson's physical pictures, where the former is based on momentum-space descriptions focusing on long wave-length fluctuations while the latter is based on real-space physics emphasizing emergent localized excitations. In particular, these two view points compete with each other in various nonperturbative phenomena, which range from the problem of high Tc superconductivity, quantum spin liquids in organic materials and frustrated spin systems, heavy-fermion quantum criticality, metal-insulator transitions in correlated electron systems such as doped silicons and two-dimensional electron systems, the fractional quantum Hall effect, to the recently discussed Fe-based superconductors. An approach to reconcile these competing frameworks is to introduce topologically nontrivial excitations into the Stoner's description, which appear to be localized in either space or time and sometimes both, where scattering between itinerant electrons and topological excitations such as skyrmions, vortices, various forms of instantons, emergent magnetic monopoles, and etc. may catch nonperturbative local physics beyond the Stoner's paradigm. In this review article we discuss nonperturbative effects of topological excitations on dynamics of correlated electrons. First, we focus on the problem of scattering between itinerant fermions and topological excitations in antiferromagnetic doped Mott insulators, expected to be relevant for the pseudogap phase of high Tc cuprates. We propose that nonperturbative effects of topological excitations can be incorporated within the perturbative framework, where an enhanced global symmetry with a topological term plays an essential role. In the second part, we go on to discuss the subject of symmetry protected topological states in a largely similar light. While we do not introduce itinerant fermions here, the nonperturbative dynamics of topological excitations is again seen to be crucial in classifying topologically nontrivial gapped systems. We point to some hidden links between several effective field theories with topological terms, starting with one dimensional physics, and subsequently finding natural generalizations to higher dimensions.

From Deficit to Diversity: How Teachers of Recently Arrived Emergent Bilinguals Negotiate Ideological and Pedagogical Change

ERIC Educational Resources Information Center

Ascenzi-Moreno, Laura

2017-01-01

Although the number and diversity of emergent bilingual students is rising, this population is viewed as homogeneous rather than vibrant and eclectic. This case study explores how two secondary teachers of English as a new language uncover the diversity of their recently arrived emergent bilingual population by implementing translanguaging…

Multiple Views of Space: Continuous Visual Flow Enhances Small-Scale Spatial Learning

ERIC Educational Resources Information Center

Holmes, Corinne A.; Marchette, Steven A.; Newcombe, Nora S.

2017-01-01

In the real word, we perceive our environment as a series of static and dynamic views, with viewpoint transitions providing a natural link from one static view to the next. The current research examined if experiencing such transitions is fundamental to learning the spatial layout of small-scale displays. In Experiment 1, participants viewed a…

Yellow-bellied marmots: insights from an emergent view of sociality.

PubMed

Blumstein, Daniel T

2013-05-19

Ecological factors explain variation in sociality both within and between species of marmots-large alpine ground squirrels. Fifty years of study, by me and my colleagues, of the yellow-bellied marmots (Marmota flaviventris) at the Rocky Mountain Biological Laboratory, near Crested Butte, CO, USA, has created opportunities to see how sociality changes with population and group size. Over the past decades, we have witnessed a natural experiment whereby the population tripled in size. If we view sociality as an emergent process, then demography acts as a constraint on interactions between individuals, and the threefold increase in population size should have consequences for group structure. We have used social network statistics to study the causes and consequences of social interactions by capitalizing on this demographic variation. Such an emergent view is ideally studied in an integrative Tinbergian way that focuses on both mechanism and function. We have determined that some social attributes are heritable, that social cohesion is established through age and kin structure, that well-embedded females (but not males) are less likely to disperse, and that there are fitness consequences of social attributes. Together, this integrative relationship-centred view expands on the traditional ecological model of sociality and offers a framework that can be applied to other systems.

Yellow-bellied marmots: insights from an emergent view of sociality

PubMed Central

Blumstein, Daniel T.

2013-01-01

Ecological factors explain variation in sociality both within and between species of marmots—large alpine ground squirrels. Fifty years of study, by me and my colleagues, of the yellow-bellied marmots (Marmota flaviventris) at the Rocky Mountain Biological Laboratory, near Crested Butte, CO, USA, has created opportunities to see how sociality changes with population and group size. Over the past decades, we have witnessed a natural experiment whereby the population tripled in size. If we view sociality as an emergent process, then demography acts as a constraint on interactions between individuals, and the threefold increase in population size should have consequences for group structure. We have used social network statistics to study the causes and consequences of social interactions by capitalizing on this demographic variation. Such an emergent view is ideally studied in an integrative Tinbergian way that focuses on both mechanism and function. We have determined that some social attributes are heritable, that social cohesion is established through age and kin structure, that well-embedded females (but not males) are less likely to disperse, and that there are fitness consequences of social attributes. Together, this integrative relationship-centred view expands on the traditional ecological model of sociality and offers a framework that can be applied to other systems. PMID:23569297

Dynamics with infinitely many time derivatives in Friedmann-Robertson-Walker background and rolling tachyons

NASA Astrophysics Data System (ADS)

Joukovskaya, Liudmila

2009-02-01

Dynamics with infinitely many time derivatives has place in string field theory and have been profoundly investigated there. Recently there has been considerable interest in theories with infinitely many derivatives in the cosmological context in view of new features which these theories might accommodate owing to nonlocal interaction. In present work we continue investigation of such models, as a concrete example we study the dynamics of unstable D-brane in the open string theory in the Friedmann-Robertson-Walker background. We construct numerical solutions describing dynamical interpolation between the perturbative and non-perturbative vacua. The obtained solutions have several interesting properties and might be of interest from the cosmological points of view.

The influence of pornography on sexual scripts and hooking up among emerging adults in college.

PubMed

Braithwaite, Scott R; Coulson, Gwen; Keddington, Krista; Fincham, Frank D

2015-01-01

The explosive growth in access to the Internet has led to a commensurate increase in the availability, anonymity, and affordability of pornography. An emerging body of research has shown associations between pornography and certain behaviors and attitudes; yet, how pornography actually influences these outcomes has not been documented. In two studies (Study 1 N = 969; Study 2 N = 992) we examined the hypothesis that pornography influences potentially risky sexual behavior (hooking up) among emerging adults via sexual scripts. Our results demonstrate that more frequent viewing of pornography is associated with a higher incidence of hooking up and a higher number of unique hook up partners. We replicated these effects both cross-sectionally and longitudinally while accounting for the stability of hook ups over the course of an academic semester. We also demonstrated that more frequent viewing of pornography is associated with having had more previous sexual partners of all types, more one occasion sexual partners ("one night stands"), and plans to have a higher number of sexual partners in the future. Finally, we provided evidence that more permissive sexual scripts mediated the association between more frequent pornography viewing and hooking up. We discuss these findings with an eye toward mitigating potential personal and public health risks among emerging adults.

Speak fast, use jargon, and don't repeat yourself: a randomized trial assessing the effectiveness of online videos to supplement emergency department discharge instructions.

PubMed

Atzema, Clare L; Austin, Peter C; Wu, Libo; Brzozowski, Michael; Feldman, Michael J; McDonnell, Michael; Mazurik, Laurie

2013-01-01

Emergency department discharge instructions are variably understood by patients, and in the setting of emergency department crowding, innovations are needed to counteract shortened interaction times with the physician. We evaluated the effect of viewing an online video of diagnosis-specific discharge instructions on patient comprehension and recall of instructions. In this prospective, single-center, randomized controlled trial conducted between November 2011 and January 2012, we randomized emergency department patients who were discharged with one of 38 diagnoses to either view (after they left the emergency department) a vetted online video of diagnosis-specific discharge instructions, or to usual care. Patients were subsequently contacted by telephone and asked three standardized questions about their discharge instructions; one point was awarded for each correct answer. Using an intention-to-treat analysis, differences between groups were assessed using univariate testing, and with logistic regression that accounted for clustering on managing physician. A secondary outcome measure was patient satisfaction with the videos, on a 10-point scale. Among 133 patients enrolled, mean age was 46.1 (s.d.D. 21.5) and 55% were female. Patients in the video group had 19% higher mean scores (2.5, s.d. 0.7) than patients in the control group (2.1, s.d. 0.8) (p=0.002). After adjustment for patient age, sex, first language, triage acuity score, and clustering, the odds of achieving a fully correct score (3 out of 3) were 3.5 (95% CI, 1.7 to 7.2) times higher in the video group, compared to the control group. Among those who viewed the videos, median rating of the videos was 10 (IQR 8 to 10). In this single-center trial, patients who viewed an online video of their discharge instructions scored higher on their understanding of key concepts around their diagnosis and subsequent care. Those who viewed the videos found them to be a helpful addition to standard care. ClinicalTrials.gov NCT01361932 http://clinicaltrials.gov/ct2/show/NCT01361932?term=nct01361932&rank=1.

Fractals, Coherence and Brain Dynamics

NASA Astrophysics Data System (ADS)

Vitiello, Giuseppe

2010-11-01

I show that the self-similarity property of deterministic fractals provides a direct connection with the space of the entire analytical functions. Fractals are thus described in terms of coherent states in the Fock-Bargmann representation. Conversely, my discussion also provides insights on the geometrical properties of coherent states: it allows to recognize, in some specific sense, fractal properties of coherent states. In particular, the relation is exhibited between fractals and q-deformed coherent states. The connection with the squeezed coherent states is also displayed. In this connection, the non-commutative geometry arising from the fractal relation with squeezed coherent states is discussed and the fractal spectral properties are identified. I also briefly discuss the description of neuro-phenomenological data in terms of squeezed coherent states provided by the dissipative model of brain and consider the fact that laboratory observations have shown evidence that self-similarity characterizes the brain background activity. This suggests that a connection can be established between brain dynamics and the fractal self-similarity properties on the basis of the relation discussed in this report between fractals and squeezed coherent states. Finally, I do not consider in this paper the so-called random fractals, namely those fractals obtained by randomization processes introduced in their iterative generation. Since self-similarity is still a characterizing property in many of such random fractals, my conjecture is that also in such cases there must exist a connection with the coherent state algebraic structure. In condensed matter physics, in many cases the generation by the microscopic dynamics of some kind of coherent states is involved in the process of the emergence of mesoscopic/macroscopic patterns. The discussion presented in this paper suggests that also fractal generation may provide an example of emergence of global features, namely long range correlation at mesoscopic/macroscopic level, from microscopic local deformation processes. In view of the wide spectrum of application of both, fractal studies and coherent state physics, spanning from solid state physics to laser physics, quantum optics, complex dynamical systems and biological systems, the results presented in the present report may lead to interesting practical developments in many research sectors.

3. Credit BG. Interior view looks northeast (46°) at fire ...

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

3. Credit BG. Interior view looks northeast (46°) at fire pumps, valves, and emergency generator (powered by an internal combustion engine). - Edwards Air Force Base, North Base, Deluge Water Pumping Station, Near Second & D Streets, Boron, Kern County, CA

ECOSYSTEM MANAGEMENT: DESPERATELY SEEKING A PARADIGM

EPA Science Inventory

Two competing views of ecosystem management have emerged. One is that ecosystem management is another stage in the continual evolution of the basic management paradigm - one that natural resource managers have followed in North America for a century. The other view is that ecosys...

MoniQA: a general approach to monitor quality assurance

NASA Astrophysics Data System (ADS)

Jacobs, J.; Deprez, T.; Marchal, G.; Bosmans, H.

2006-03-01

MoniQA ("Monitor Quality Assurance") is a new, non-commercial, independent quality assurance software application developed in our medical physics team. It is a complete Java TM - based modular environment for the evaluation of radiological viewing devices and it thus fits in the global quality assurance network of our (film less) radiology department. The purpose of the software tool is to guide the medical physicist through an acceptance protocol and the radiologist through a constancy check protocol by presentation of the necessary test patterns and by automated data collection. Data are then sent to a central management system for further analysis. At the moment more than 55 patterns have been implemented, which can be grouped in schemes to implement protocols (i.e. AAPMtg18, DIN and EUREF). Some test patterns are dynamically created and 'drawn' on the viewing device with random parameters as is the case in a recently proposed new pattern for constancy testing. The software is installed on 35 diagnostic stations (70 monitors) in a film less radiology department. Learning time was very limited. A constancy check -with the new pattern that assesses luminance decrease, resolution problems and geometric distortion- takes only 2 minutes and 28 seconds per monitor. The modular approach of the software allows the evaluation of new or emerging test patterns. We will report on the software and its usability: practicality of the constancy check tests in our hospital and on the results from acceptance tests of viewing stations for digital mammography.

Today´s medical self and the other: Challenges and evolving solutions for enhanced humanization and quality of care

PubMed Central

Quintana-Vargas, Silvia; Ruddick, William; Castro-Santana, Anaclara; Islas-Andrade, Sergio; Altamirano-Bustamante, Nelly F.

2017-01-01

Background Recent scientific developments, along with growing awareness of cultural and social diversity, have led to a continuously growing range of available treatment options; however, such developments occasionally lead to an undesirable imbalance between science, technology and humanism in clinical practice. This study explores the understanding and practice of values and value clusters in real-life clinical settings, as well as their role in the humanization of medicine and its institutions. The research focuses on the values of clinical practice as a means of finding ways to enhance the pairing of Evidence-Based Medicine (EBM) with Values-based Medicine (VBM) in daily practice. Methods and findings The views and representations of clinical practice in 15 pre-CME and 15 post-CME interviews were obtained from a random sampling of active healthcare professionals. These views were then identified and qualitatively analyzed using a three-step hermeneutical approach. A clinical values space was identified in which ethical and epistemic values emerge, grow and develop within the biomedical, ethical, and socio-economic dimensions of everyday health care. Three main values—as well as the dynamic clusters and networks that they tend to form—were recognized: healthcare personnel-patient relationships, empathy, and respect. An examination of the interviews suggested that an adequate conceptualization of values leads to the formation of a wider axiological system. The role of clinician-as-consociate emerged as an ideal for achieving medical excellence. Conclusions By showing the intricate clusters and networks into which values are interwoven, our analysis suggests methods for fine-tuning educational interventions so they can lead to demonstrable changes in attitudes and practices. PMID:28759585

Today´s medical self and the other: Challenges and evolving solutions for enhanced humanization and quality of care.

PubMed

Sueiras, Perla; Romano-Betech, Victoria; Vergil-Salgado, Alejandro; de Hoyos, Adalberto; Quintana-Vargas, Silvia; Ruddick, William; Castro-Santana, Anaclara; Islas-Andrade, Sergio; Altamirano-Bustamante, Nelly F; Altamirano-Bustamante, Myriam M

2017-01-01

Recent scientific developments, along with growing awareness of cultural and social diversity, have led to a continuously growing range of available treatment options; however, such developments occasionally lead to an undesirable imbalance between science, technology and humanism in clinical practice. This study explores the understanding and practice of values and value clusters in real-life clinical settings, as well as their role in the humanization of medicine and its institutions. The research focuses on the values of clinical practice as a means of finding ways to enhance the pairing of Evidence-Based Medicine (EBM) with Values-based Medicine (VBM) in daily practice. The views and representations of clinical practice in 15 pre-CME and 15 post-CME interviews were obtained from a random sampling of active healthcare professionals. These views were then identified and qualitatively analyzed using a three-step hermeneutical approach. A clinical values space was identified in which ethical and epistemic values emerge, grow and develop within the biomedical, ethical, and socio-economic dimensions of everyday health care. Three main values-as well as the dynamic clusters and networks that they tend to form-were recognized: healthcare personnel-patient relationships, empathy, and respect. An examination of the interviews suggested that an adequate conceptualization of values leads to the formation of a wider axiological system. The role of clinician-as-consociate emerged as an ideal for achieving medical excellence. By showing the intricate clusters and networks into which values are interwoven, our analysis suggests methods for fine-tuning educational interventions so they can lead to demonstrable changes in attitudes and practices.

Perceptions of social and environmental changes in a Mediterranean forest during the last 100 years: the Gavarres Massif.

PubMed

Rodríguez-Carreras, Roser; Ubeda, Xavier; Outeiro, Luís; Asperó, Francesc

2014-06-01

During the last century the landscape of the mid-Mediterranean mountains has undergone major transformations. The precipitous decline in the economic viability of forest products has engendered ever-thickening forests and agricultural lands have reverted to forest land cover. The related exodus of existing inhabitants since 1960 has led to new styles of occupancy: residential and touristic land uses have emerged while the primary and secondary sectors have largely disappeared. The object of the present study is to review how these transformations have developed in a specific area of north-eastern of Catalonia, known as the Gavarres Massif. The study applies a qualitative approach, based on interviews with stakeholders including active members of the local community and others who utilize or visit the area, all of whom are representatives of different social groups with a wide range of interests and points of view with regard to the massif. The information collected from the perspectives and opinions of the participants is coupled with objective data about the area. The result of this investigation is a rich variety of perceptions on landscape and social transformation and its current functional dynamics. Analyzing the information obtained allows us to understand the fact that the disappearance of the rural world is directly related to the collapse of an entire economic system that relied on the environment. In this study, two divergent points of view arise, one which supports recovering past landscapes and another which favours managing changes, conserving the existing landscape. Proposals for the current and future territorial management of Les Gavarres are presented. The diversity of opinions which emerges with regard to managing necessary changes in the massif emphasizes the importance of increased social dialogue. Copyright © 2013 Elsevier Ltd. All rights reserved.

Patients' views of teamwork in the emergency department offer insights about team performance.

PubMed

Henry, Beverly W; McCarthy, Danielle M; Nannicelli, Anna P; Seivert, Nicholas P; Vozenilek, John A

2016-06-01

Research into efforts to engage patients in the assessment of health-care teams is limited. To explore, through qualitative methods, patient awareness of teamwork-related behaviours observed during an emergency department (ED) visit. Researchers used semi-structured question guides for audio-recorded interviews and analysed their verbatim transcripts. Researchers conducted individual phone interviews with 6 teamwork subject matter experts (SMEs) and held 5 face-to-face group interviews with patients and caregivers (n = 25) about 2 weeks after discharge from the emergency department (ED). SMEs suggested that a range of factors influence patient perspectives of teams. Many patients perceived the health-care team within the context of their expectations of an ED visit and their treatment plan. Four themes emerged: (i) patient-centred views highlight gaps in coordination and communication; (ii) team processes do concern patients; (iii) patients are critical observers of ways that team members present their team roles; (iv) patients' observations of team members relate to patients' views of team effectiveness. Analysis also indicated that patients viewed health-care team members' interactions with each other as proxy for how team members actually felt about patients. Results from both sets of interviews (SME and patient) indicated that patient observations of teamwork could add to assessment of team processes/frameworks. Patients' understanding about teamwork organization seemed helpful and witnessed interteam communication appeared to influence patient confidence in the team. Patients perspectives are an important part of assessment in health care and suggest potential areas for improvement through team training. © 2013 John Wiley & Sons Ltd.

Minimalistic Dynamic Climbing

DTIC Science & Technology

2010-11-01

connected. On this same disk, a servo motor is connected to a light weight leg. An Arduino 77 Body Weight Markers Leg Disk Servo Motor Front View Top View...this control enables more dynamic and fast walking, the control is based on precise joint-angle control. The main consequence of such a control is that... based climbing strategies. Specifically, the four-limbed free-climbing LEMUR robot goes up climbing walls by choosing a sequence of handholds

Argumentation Text Construction by Japanese as a Foreign Language Writers: A Dynamic View of Transfer

ERIC Educational Resources Information Center

Rinnert, Carol; Kobauashi, Hiroe; Katayama, Akemi

2015-01-01

This study takes a dynamic view of transfer as reusing and reshaping previous knowledge in new writing contexts to investigate how novice Japanese as a foreign language (JFL) writers draw on knowledge across languages to construct L1 and L2 texts. We analyzed L1 English and L2 Japanese argumentation essays by the same JFL writers (N = 19) and L1…

Predicting the Dynamics of Protein Abundance

PubMed Central

Mehdi, Ahmed M.; Patrick, Ralph; Bailey, Timothy L.; Bodén, Mikael

2014-01-01

Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA–protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation efficiency. The software and data used in this research are available at http://bioinf.scmb.uq.edu.au/proteinabundance/. PMID:24532840

Predicting the dynamics of protein abundance.

PubMed

Mehdi, Ahmed M; Patrick, Ralph; Bailey, Timothy L; Bodén, Mikael

2014-05-01

Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA-protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation efficiency. The software and data used in this research are available at http://bioinf.scmb.uq.edu.au/proteinabundance/.

77 FR 50546 - Agency Information Collection: Emergency Submission for OMB Review (CEPACT (Center for Evaluation...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-21

... emergency clearance is being requested for information needed to focus on patient experiences with and views... leadership in health care quality. This will be done to evaluate the effectiveness of various types of care...

Massive, Open, Online, and National? A Study of How National Governments and Institutions Shape the Development of MOOCs

ERIC Educational Resources Information Center

Tømte, Cathrine E.; Fevolden, Arne Martin; Aanstad, Siri

2017-01-01

We explore interpretations of MOOCs around the globe and, in particular, interpretations of MOOCs in Norway. Based on a review of previous studies relevant to these topics, we present two contrasting views on the emergence and development of MOOCs, namely the global interruption view and the national mediation view. We suggest, based on previous…

Gathering the Dreamers: The Transformation Process to a Learner-Centered School. The Reinventing School Series. Part Two and Viewing Guide. Videotape.

ERIC Educational Resources Information Center

Burrello, Leonard C.; DiLaura, Nancy

This videotape and viewing guide present an emerging learner-centered paradigm of teaching and learning and answer questions of why and how a staff changes its practices. The viewing guide describes the elementary school in the videotape, noting the full inclusion of 50 students identified as disabled, the team approach in which teachers are…

Remote Visualization and Remote Collaboration On Computational Fluid Dynamics

NASA Technical Reports Server (NTRS)

Watson, Val; Lasinski, T. A. (Technical Monitor)

1995-01-01

A new technology has been developed for remote visualization that provides remote, 3D, high resolution, dynamic, interactive viewing of scientific data (such as fluid dynamics simulations or measurements). Based on this technology, some World Wide Web sites on the Internet are providing fluid dynamics data for educational or testing purposes. This technology is also being used for remote collaboration in joint university, industry, and NASA projects in computational fluid dynamics and wind tunnel testing. Previously, remote visualization of dynamic data was done using video format (transmitting pixel information) such as video conferencing or MPEG movies on the Internet. The concept for this new technology is to send the raw data (e.g., grids, vectors, and scalars) along with viewing scripts over the Internet and have the pixels generated by a visualization tool running on the viewer's local workstation. The visualization tool that is currently used is FAST (Flow Analysis Software Toolkit).

View of first level from east looking at the central ...

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

View of first level from east looking at the central bay. Interstitial structure is in the foreground center, main structure is in background left and right of view. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

Unraveling hidden order in the dynamics of developed and emerging markets.

PubMed

Berman, Yonatan; Shapira, Yoash; Ben-Jacob, Eshel

2014-01-01

The characterization of asset price returns is an important subject in modern finance. Traditionally, the dynamics of stock returns are assumed to lack any temporal order. Here we present an analysis of the autocovariance of stock market indices and unravel temporal order in several major stock markets. We also demonstrate a fundamental difference between developed and emerging markets in the past decade - emerging markets are marked by positive order in contrast to developed markets whose dynamics are marked by weakly negative order. In addition, the reaction to financial crises was found to be reversed among developed and emerging markets, presenting large positive/negative autocovariance spikes following the onset of these crises. Notably, the Chinese market shows neutral or no order while being regarded as an emerging market. These findings show that despite the coupling between international markets and global trading, major differences exist between different markets, and demonstrate that the autocovariance of markets is correlated with their stability, as well as with their state of development.

Unraveling Hidden Order in the Dynamics of Developed and Emerging Markets

PubMed Central

Berman, Yonatan; Shapira, Yoash; Ben-Jacob, Eshel

2014-01-01

The characterization of asset price returns is an important subject in modern finance. Traditionally, the dynamics of stock returns are assumed to lack any temporal order. Here we present an analysis of the autocovariance of stock market indices and unravel temporal order in several major stock markets. We also demonstrate a fundamental difference between developed and emerging markets in the past decade - emerging markets are marked by positive order in contrast to developed markets whose dynamics are marked by weakly negative order. In addition, the reaction to financial crises was found to be reversed among developed and emerging markets, presenting large positive/negative autocovariance spikes following the onset of these crises. Notably, the Chinese market shows neutral or no order while being regarded as an emerging market. These findings show that despite the coupling between international markets and global trading, major differences exist between different markets, and demonstrate that the autocovariance of markets is correlated with their stability, as well as with their state of development. PMID:25383630

Dynamic Defensive Posture for Computer Network Defence

DTIC Science & Technology

2006-12-01

12 4.1.1 Skybox View . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.1.2 CycSecure...Commercial projects 4.1.1 Skybox View Skybox View is a commercial product that aims to evaluate network risk by iden- tifying network resources that are...changes before implementing them on the live network. In these respects, it is a tool for identifying exposed resources. Skybox View also permits some

Guidelines for applying the Composite Specification Model (CSM)

NASA Technical Reports Server (NTRS)

Agresti, William

1987-01-01

The Composite Specification Model (CSM) is an approach to representing software requirements. Guidelines are provided for applying CSM and developing each of the three descriptive views of the software: the contextual view, using entities and relationships; the dynamic view, using states and transitions; and the function view, using data flows and processes. Using CSM results in a software specification document, which is outlined.

The role of pre-oedipal and oedipal factors in psychic life.

PubMed

Kancyper, Luis

2006-02-01

The Oedipus complex, a basic concept in Freudian theory, is an essential factor in the constitution of the human subject. It plays a key role in the structuring of the personality and in the orientation of desire. It is the oedipal triangular structure that precedes the pre-oedipal situation (in a logical, not chronological, order), and not vice versa. The oedipal structure exists before the infant's biological birth. It is present in the parents' desires and identifications, which inexorably fall upon each subject. That is why the author believes that it is necessary to leave behind a solipsistic reading of the nuclear complex of neuroses--a reading that is based solely on Oedipus's drive nucleus--and take a joint and comprehensive view of Laius's and Jocasta's histories and traumatic experiences, which were invested in their son. Among these three vertices, a dynamic set of forces emerges whereby a basic, original unconscious field phantasy is created that bears a unique narrative and an invisible and hermetic web made of passions and beliefs, scandals and secrets. This phantasy gives shape to an unrepeatable oedipal structure in each subject, a structure that articulates with the effects of the narcissistic and fraternal dynamic and may determine the subject's fate. This paper develops the following issues: 1) Oedipus, victimizer or victim?; 2) the generational confrontation as dynamic field; and 3) neuroses with a preponderance of dualistic relationships.

Moving through a multiplex holographic scene

NASA Astrophysics Data System (ADS)

Mrongovius, Martina

2013-02-01

This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

A Constructive Mean-Field Analysis of Multi-Population Neural Networks with Random Synaptic Weights and Stochastic Inputs

PubMed Central

Faugeras, Olivier; Touboul, Jonathan; Cessac, Bruno

2008-01-01

We deal with the problem of bridging the gap between two scales in neuronal modeling. At the first (microscopic) scale, neurons are considered individually and their behavior described by stochastic differential equations that govern the time variations of their membrane potentials. They are coupled by synaptic connections acting on their resulting activity, a nonlinear function of their membrane potential. At the second (mesoscopic) scale, interacting populations of neurons are described individually by similar equations. The equations describing the dynamical and the stationary mean-field behaviors are considered as functional equations on a set of stochastic processes. Using this new point of view allows us to prove that these equations are well-posed on any finite time interval and to provide a constructive method for effectively computing their unique solution. This method is proved to converge to the unique solution and we characterize its complexity and convergence rate. We also provide partial results for the stationary problem on infinite time intervals. These results shed some new light on such neural mass models as the one of Jansen and Rit (1995): their dynamics appears as a coarse approximation of the much richer dynamics that emerges from our analysis. Our numerical experiments confirm that the framework we propose and the numerical methods we derive from it provide a new and powerful tool for the exploration of neural behaviors at different scales. PMID:19255631

Dynamic domains of the Derviche Tourneur sodium experiment: Simulations of a spherical magnetized Couette flow

NASA Astrophysics Data System (ADS)

Kaplan, E. J.; Nataf, H.-C.; Schaeffer, N.

2018-03-01

The Derviche Tourneur sodium experiment, a spherical Couette magnetohydrodynamics experiment with liquid sodium as the medium and a dipole magnetic field imposed from the inner sphere, recently underwent upgrades to its diagnostics to better characterize the flow and induced magnetic fields with global rotation. In tandem with the upgrades, a set of direct numerical simulations were run to give a more complete view of the fluid and magnetic dynamics at various rotation rates of the inner and outer spheres. These simulations reveal several dynamic regimes, determined by the Rossby number. At positive differential rotation there is a regime of quasigeostrophic flow, with low levels of fluctuations near the outer sphere. Negative differential rotation shows a regime of what appear to be saturated hydrodynamic instabilities at low negative differential rotation, followed by a regime where filamentary structures develop at low latitudes and persist over five to ten differential rotation periods as they drift poleward. We emphasize that all these coherent structures emerge from turbulent flows. At least some of them seem to be related to linear instabilities of the mean flow. The simulated flows can produce the same measurements as those that the physical experiment can take, with signatures akin to those found in the experiment. This paper discusses the relation between the internal velocity structures of the flow and their magnetic signatures at the surface.

Construction of an evaluation and selection system of emergency treatment technology based on dynamic fuzzy GRA method for phenol spill

NASA Astrophysics Data System (ADS)

Zhao, Jingjing; Yu, Lean; Li, Lian

2017-05-01

There is often a great deal of complexity, fuzziness and uncertainties of the chemical contingency spills. In order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs, the technique evaluation system was developed based on dynamic fuzzy GRA method, and the feasibility of the proposed methods has been tested by using a emergency phenol spill accidence occurred in highway.

The effect of monocular and binocular viewing on the accommodation response to real targets in emmetropia and myopia.

PubMed

Seidel, Dirk; Gray, Lyle S; Heron, Gordon

2005-04-01

Decreased blur-sensitivity found in myopia has been linked with reduced accommodation responses and myopigenesis. Although the mechanism for myopia progression remains unclear, it is commonly known that myopic patients rarely report near visual symptoms and are generally very sensitive to small changes in their distance prescription. This experiment investigated the effect of monocular and binocular viewing on static and dynamic accommodation in emmetropes and myopes for real targets to monitor whether inaccuracies in the myopic accommodation response are maintained when a full set of visual cues, including size and disparity, is available. Monocular and binocular steady-state accommodation responses were measured with a Canon R1 autorefractor for target vergences ranging from 0-5 D in emmetropes (EMM), late-onset myopes (LOM), and early-onset myopes (EOM). Dynamic closed-loop accommodation responses for a stationary target at 0.25 m and step stimuli of two different magnitudes were recorded for both monocular and binocular viewing. All refractive groups showed similar accommodation stimulus response curves consistent with previously published data. Viewing a stationary near target monocularly, LOMs demonstrated slightly larger accommodation microfluctuations compared with EMMs and EOMs; however, this difference was absent under binocular viewing conditions. Dynamic accommodation step responses revealed significantly (p < 0.05) longer response times for the myopic subject groups for a number of step stimuli. No significant difference in either reaction time or the number of correct responses for a given number of step-vergence changes was found between the myopic groups and EMMs. When viewing real targets with size and disparity cues available, no significant differences in the accuracy of static and dynamic accommodation responses were found among EMM, EOM, and LOM. The results suggest that corrected myopes do not experience dioptric blur levels that are substantially different from emmetropes when they view free space targets.

Atomic-level description of ubiquitin folding

PubMed Central

Piana, Stefano; Lindorff-Larsen, Kresten; Shaw, David E.

2013-01-01

Equilibrium molecular dynamics simulations, in which proteins spontaneously and repeatedly fold and unfold, have recently been used to help elucidate the mechanistic principles that underlie the folding of fast-folding proteins. The extent to which the conclusions drawn from the analysis of such proteins, which fold on the microsecond timescale, apply to the millisecond or slower folding of naturally occurring proteins is, however, unclear. As a first attempt to address this outstanding issue, we examine here the folding of ubiquitin, a 76-residue-long protein found in all eukaryotes that is known experimentally to fold on a millisecond timescale. Ubiquitin folding has been the subject of many experimental studies, but its slow folding rate has made it difficult to observe and characterize the folding process through all-atom molecular dynamics simulations. Here we determine the mechanism, thermodynamics, and kinetics of ubiquitin folding through equilibrium atomistic simulations. The picture emerging from the simulations is in agreement with a view of ubiquitin folding suggested from previous experiments. Our findings related to the folding of ubiquitin are also consistent, for the most part, with the folding principles derived from the simulation of fast-folding proteins, suggesting that these principles may be applicable to a wider range of proteins. PMID:23503848

Lamins in the nuclear interior - life outside the lamina.

PubMed

Naetar, Nana; Ferraioli, Simona; Foisner, Roland

2017-07-01

Nuclear lamins are components of the peripheral lamina that define the mechanical properties of nuclei and tether heterochromatin to the periphery. A-type lamins localize also to the nuclear interior, but the regulation and specific functions of this nucleoplasmic lamin pool are poorly understood. In this Commentary, we summarize known pathways that are potentially involved in the localization and dynamic behavior of intranuclear lamins, including their post-translational modifications and interactions with nucleoplasmic proteins, such as lamina-associated polypeptide 2α (LAP2α; encoded by TMPO ). In addition, new data suggest that lamins in the nuclear interior have an important role in chromatin regulation and gene expression through dynamic binding to both hetero- and euchromatic genomic regions and promoter subdomains, thereby affecting epigenetic pathways and chromatin accessibility. Nucleoplasmic lamins also have a role in spatial chromatin organization and may be involved in mechanosignaling. In view of this newly emerging concept, we propose that the previously reported cellular phenotypes in lamin-linked diseases are, at least in part, rooted in an impaired regulation and/or function of the nucleoplasmic lamin A/C pool. © 2017. Published by The Company of Biologists Ltd.

Reinforcing the membrane-mediated mechanism of action of the anti-tuberculosis candidate drug thioridazine with molecular simulations

NASA Astrophysics Data System (ADS)

Kopec, Wojciech; Khandelia, Himanshu

2014-02-01

Thioridazine is a well-known dopamine-antagonist drug with a wide range of pharmacological properties ranging from neuroleptic to antimicrobial and even anticancer activity. Thioridazine is a critical component of a promising multi-drug therapy against M. tuberculosis. Amongst the various proposed mechanisms of action, the cell membrane-mediated one is peculiarly tempting due to the distinctive feature of phenothiazine drug family to accumulate in selected body tissues. In this study, we employ long-scale molecular dynamics simulations to investigate the interactions of three different concentrations of thioridazine with zwitterionic and negatively charged model lipid membranes. Thioridazine partitions into the interfacial region of membranes and modifies their structural and dynamic properties, however dissimilarly so at the highest membrane-occurring concentration, that appears to be obtainable only for the negatively charged bilayer. We show that the origin of such changes is the drug induced decrease of the interfacial tension, which ultimately leads to the significant membrane expansion. Our findings support the hypothesis that the phenothiazines therapeutic activity may arise from the drug-membrane interactions, and reinforce the wider, emerging view of action of many small, bioactive compounds.

Virtual microscopy beyond the pyramids, applications of WSI in Cairo University for E-education & telepathology.

PubMed

Ayad, Essam; Yagi, Yukako

2012-01-01

Telepathology, the practice of pathology at a long distance, has advanced continuously since 1986. The progress of telepathology passed through four stages: Static, Dynamic, Hybrid & Whole Slide Imaging. A pilot project between the Italian Hospital in Cairo & the Civico Hospital in Palermo was completed successfully, applying the static & dynamic techniques of telepathology. This project began in 2003 and continued till now. In 2004, centers in Venice, London and Pittsburgh participated actively in our project. Over eight years we consulted on many problematic pathological cases with specialized pathological centers in Italy, U.K. & U.S.A. In addition to the highly specialized scientific value, we saved a lot of time and money. We concluded from our experience that telepathology is a very useful and applicable tool for additional consulting on difficult pathological cases especially for emerging countries. In view of this success we have already established our Digital Telepathology Unit in Cairo University, using the WSI technique in teaching which was greatly successful and encouraged us to build a huge digital pathology library which will expand our telepathology & E-learning programs to cover staff and students in Egypt and Eastern Mediterranean.

Virtual Microscopy Beyond the Pyramids, Applications of WSI in Cairo University for E-Education & Telepathology

PubMed Central

Ayad, Essam; Yagi, Yukako

2012-01-01

Background: Telepathology, the practice of pathology at a long distance, has advanced continuously since 1986. The progress of telepathology passed through four stages: Static, Dynamic, Hybrid & Whole Slide Imaging. Materials and Methods: A pilot project between the Italian Hospital in Cairo & the Civico Hospital in Palermo was completed successfully, applying the static & dynamic techniques of telepathology. This project began in 2003 and continued till now. In 2004, centers in Venice, London and Pittsburgh participated actively in our project. Results: Over eight years we consulted on many problematic pathological cases with specialized pathological centers in Italy, UK & USA. In addition to the highly specialized scientific value, we saved a lot of time and money. Conclusion: We concluded from our experience that telepathology is a very useful and applicable tool for additional consulting on difficult pathological cases especially for emerging countries. In view of this success we have already established our Digital Telepathology Unit in Cairo University, using the WSI technique in teaching which was greatly successful and encouraged us to build a huge digital pathology library which will expand our telepathology & E-learning programs to cover staff and students in Egypt and Eastern Mediterranean. PMID:22297472

Negative mobility of a Brownian particle: Strong damping regime

NASA Astrophysics Data System (ADS)

Słapik, A.; Łuczka, J.; Spiechowicz, J.

2018-02-01

We study impact of inertia on directed transport of a Brownian particle under non-equilibrium conditions: the particle moves in a one-dimensional periodic and symmetric potential, is driven by both an unbiased time-periodic force and a constant force, and is coupled to a thermostat of temperature T. Within selected parameter regimes this system exhibits negative mobility, which means that the particle moves in the direction opposite to the direction of the constant force. It is known that in such a setup the inertial term is essential for the emergence of negative mobility and it cannot be detected in the limiting case of overdamped dynamics. We analyse inertial effects and show that negative mobility can be observed even in the strong damping regime. We determine the optimal dimensionless mass for the presence of negative mobility and reveal three mechanisms standing behind this anomaly: deterministic chaotic, thermal noise induced and deterministic non-chaotic. The last origin has never been reported. It may provide guidance to the possibility of observation of negative mobility for strongly damped dynamics which is of fundamental importance from the point of view of biological systems, all of which in situ operate in fluctuating environments.

4. VIEW NORTHEAST, radar tower (unknown function), prime search radar ...

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

4. VIEW NORTHEAST, radar tower (unknown function), prime search radar tower, emergency power building, and height finder radar tower - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

What do we perceive from motion pictures? A computational account.

PubMed

Cheong, Loong-Fah; Xiang, Xu

2007-06-01

Cinema viewed from a location other than a canonical viewing point (CVP) presents distortions to the viewer in both its static and its dynamic aspects. Past works have investigated mainly the static aspect of this problem and attempted to explain why viewers still seem to perceive the scene very well. The dynamic aspect of depth perception, which is known as structure from motion, and its possible distortion, have not been well investigated. We derive the dynamic depth cues perceived by the viewer and use the so-called isodistortion framework to understand its distortion. The result is that viewers seated at a reasonably central position experience a shift in the intrinsic parameters of their visual systems. Despite this shift, the key properties of the perceived depths remain largely the same, being determined in the main by the accuracy to which extrinsic motion parameters can be recovered. For a viewer seated at a noncentral position and watching the movie screen at a slant angle, the view is related to the view at the CVP by a homography, resulting in various aberrations such as noncentral projection.

Angular Declination and the Dynamic Perception of Egocentric Distance

PubMed Central

Gajewski, Daniel A.; Philbeck, John W.; Wirtz, Philip W.; Chichka, David

2014-01-01

The extraction of the distance between an object and an observer is fast when angular declination is informative, as it is with targets placed on the ground. To what extent does angular declination drive performance when viewing time is limited? Participants judged target distances in a real-world environment with viewing durations ranging from 36–220 ms. An important role for angular declination was supported by experiments showing that the cue provides information about egocentric distance even on the very first glimpse, and that it supports a sensitive response to distance in the absence of other useful cues. Performance was better at 220 ms viewing durations than for briefer glimpses, suggesting that the perception of distance is dynamic even within the time frame of a typical eye fixation. Critically, performance in limited viewing trials was better when preceded by a 15 second preview of the room without a designated target. The results indicate that the perception of distance is powerfully shaped by memory from prior visual experience with the scene. A theoretical framework for the dynamic perception of distance is presented. PMID:24099588

44 CFR Appendix A to Part 353 - Memorandum of Understanding Between Federal Emergency Management Agency and Nuclear Regulatory...

Code of Federal Regulations, 2010 CFR

2010-10-01

... NRC that an emergency, unforeseen contingency, or other reason would prevent FEMA from providing a... they are revised to correct deficiencies noted in the Federal review. If, in FEMA's view, the plans...

Spontaneous Facial Mimicry in Response to Dynamic Facial Expressions

ERIC Educational Resources Information Center

Sato, Wataru; Yoshikawa, Sakiko

2007-01-01

Based on previous neuroscientific evidence indicating activation of the mirror neuron system in response to dynamic facial actions, we hypothesized that facial mimicry would occur while subjects viewed dynamic facial expressions. To test this hypothesis, dynamic/static facial expressions of anger/happiness were presented using computer-morphing…

Signalling crosstalk in plants: emerging issues.

PubMed

Taylor, Jane E; McAinsh, Martin R

2004-01-01

The Oxford English Dictionary defines crosstalk as 'unwanted transfer of signals between communication channels'. How does this definition relate to the way in which we view the organization and function of signalling pathways? Recent advances in the field of plant signalling have challenged the traditional view of a signalling transduction cascade as isolated linear pathways. Instead the picture emerging of the mechanisms by which plants transduce environmental signals is of the interaction between transduction chains. The manner in which these interactions occur (and indeed whether the transfer of these signals is 'unwanted' or beneficial) is currently the topic of intense research.

Six-Position, Frontal View Photography in Blepharoplasty: A Simple Method.

PubMed

Zhang, Cheng; Guo, Xiaoshuang; Han, Xuefeng; Tian, Yi; Jin, Xiaolei

2018-02-26

Photography plays a pivotal role in patient education, photo-documentation, preoperative planning and postsurgical evaluation in plastic surgeries. It has long been serving as a bridge that facilitated communication not only between patients and doctors, but also among plastic surgeons from different countries. Although several basic principles and photographic methods have been proposed, there is no internationally accepted photography that could provide both static and dynamic information in blepharoplasty. In this article, we introduced a novel six-position, frontal view photography for thorough assessment in blepharoplasty. From October 2013 to January 2017, 1068 patients who underwent blepharoplasty were enrolled in our clinical research. All patients received six-position, frontal view photography. Pictures were taken of the patients looking up, looking down, squeezing, smiling, looking ahead and with closed eyes. Conventionally, frontal view photography only contained the last two positions. Then, both novel six-position photographs and conventional two-position photographs were used to appraise postsurgical outcomes. Compared to conventional two-position, frontal view photography, six-position, frontal view photography can provide more detailed, thorough information about the eyes. It is of clinical significance in indicating underlying adhesion of skin/muscle/fat according to individual's features and assessing preoperative and postoperative dynamic changes and aesthetic outcomes. Six-position, frontal view photography is technically uncomplicated while exhibiting static, dynamic and detailed information of the eyes. This innovative method is favorable in eye assessment, especially for revision blepharoplasty. We suggest using six-position, frontal view photography to obtain comprehensive photographs. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Understanding the dynamic effects of returning patients toward emergency department density

NASA Astrophysics Data System (ADS)

Ahmad, Norazura; Zulkepli, Jafri; Ramli, Razamin; Ghani, Noraida Abdul; Teo, Aik Howe

2017-11-01

This paper presents the development of a dynamic hypothesis for the effect of returning patients to the emergency department (ED). A logical tree from the Theory of Constraint known as Current Reality Tree was used to identify the key variables. Then, a hypothetical framework portraying the interrelated variables and its influencing relationships was developed using causal loop diagrams (CLD). The conceptual framework was designed as the basis for the development of a system dynamics model.

Dynamical origin of complex motor patterns

NASA Astrophysics Data System (ADS)

Alonso, L. M.; Alliende, J. A.; Mindlin, G. B.

2010-11-01

Behavior emerges as the nervous system generates motor patterns in charge of driving a peripheral biomechanical device. For several cases in the animal kingdom, it has been identified that the motor patterns used in order to accomplish a diversity of tasks are the different solutions of a simple, low dimensional nonlinear dynamical system. Yet, motor patterns emerge from the interaction of an enormous number of individual dynamical units. In this work, we study the dynamics of the average activity of a large set of coupled excitable units which are periodically forced. We show that low dimensional, yet non trivial dynamics emerges. As a case study, we analyze the air sac pressure patterns used by domestic canaries during song, which consists of a succession of repetitions of different syllable types. We show that the pressure patterns used to generate different syllables can be approximated by the solutions of the investigated model. In this way, we are capable of integrating different description scales of our problem.

The Resilience of Coral Reefs Across a Hierarchy of Spatial and Temporal scales

NASA Astrophysics Data System (ADS)

Mumby, P. J.

2016-02-01

Resilience is a dynamical property of ecosystems that integrates processes of recovery, disturbance and internal dynamics, including reinforcing feedbacks. As such, resilience is a useful framework to consider how ecosystems respond to multiple drivers occurring over multiple scales. Many insights have emerged recently including the way in which stressors can combine synergistically to deplete resilience. However, while recent advances have mapped resilience across seascapes, most studies have not captured emergent spatial dependencies and dynamics across the seascape (e.g., independent box models are run across the seascape in isolation). Here, we explore the dynamics that emerge when the seascape is `wired up' using data on larval dispersal, thereby giving a fully spatially-realistic model. We then consider how dynamics change across even larger, biogeographic scales, posing the question, `are there robust and global "rules of thumb" for the resilience of a single ecosystem?'. Answers to this question will help managers tailor their interventions and research needs for their own jurisdiction.

A Satellite-Based Lagrangian View on Phytoplankton Dynamics

NASA Astrophysics Data System (ADS)

Lehahn, Yoav; d'Ovidio, Francesco; Koren, Ilan

2018-01-01

The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter—the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this Lagrangian perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the Lagrangian view of phytoplankton dynamics.

A Satellite-Based Lagrangian View on Phytoplankton Dynamics.

PubMed

Lehahn, Yoav; d'Ovidio, Francesco; Koren, Ilan

2018-01-03

The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter-the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this Lagrangian perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the Lagrangian view of phytoplankton dynamics.

Dynamics of large-diameter water pipes in hydroelectric power plants

NASA Astrophysics Data System (ADS)

Pavić, G.; Chevillotte, F.; Heraud, J.

2017-04-01

An outline is made of physical behaviour of water - filled large pipes. The fluid-wall coupling, the key factor governing the pipe dynamics, is discussed in some detail. Different circumferential pipe modes and the associated cut-on frequencies are addressed from a theoretical as well as practical point of view. Major attention is paid to the breathing mode in view of its importance regarding main dynamic phenomena, such as water hammer. Selected measurement results done at EDF are presented to demonstrate how an external, non-intrusive sensor can detect pressure pulsations of the breathing mode in a pressure pipe. Differences in the pressure measurement using intrusive and non-intrusive sensors reveal the full complexity of large-diameter pipe dynamics.

A framework to observe and evaluate the sustainability of human-natural systems in a complex dynamic context.

PubMed

Satanarachchi, Niranji; Mino, Takashi

2014-01-01

This paper aims to explore the prominent implications of the process of observing complex dynamics linked to sustainability in human-natural systems and to propose a framework for sustainability evaluation by introducing the concept of sustainability boundaries. Arguing that both observing and evaluating sustainability should engage awareness of complex dynamics from the outset, we try to embody this idea in the framework by two complementary methods, namely, the layer view- and dimensional view-based methods, which support the understanding of a reflexive and iterative sustainability process. The framework enables the observation of complex dynamic sustainability contexts, which we call observation metastructures, and enable us to map the contexts to sustainability boundaries.

Functional organization of primate translational vestibulo-ocular reflexes and effects of unilateral labyrinthectomy

NASA Technical Reports Server (NTRS)

Angelaki, D. E.; McHenry, M. Q.; Newlands, S. D.; Dickman, J. D.

1999-01-01

Translational vestibulo-ocular reflexes (trVORs) are characterized by distinct spatio-temporal properties and sensitivities that are proportional to the inverse of viewing distance. Anodal (inhibitory) labyrinthine stimulation (100 microA, < 2 s) during motion decreased the high-pass filtered dynamics, as well as horizontal trVOR sensitivity and its dependence on viewing distance. Cathodal (excitatory) currents had opposite effects. Translational VORs were also affected after unilateral labyrinthectomy. Animals lost their ability to modulate trVOR sensitivity as a function of viewing distance acutely after the lesion. These deficits partially recovered over time, albeit a significant reduction in trVOR sensitivity as a function of viewing distance remained in compensated animals. During fore-aft motion, the effects of unilateral labyrinthectomy were more dramatic. Both acute and compensated animals permanently lost their ability to modulate fore-aft trVOR responses as a function of target eccentricity. These results suggest that (1) the dynamics and viewing distance-dependent properties of the trVORs are very sensitive to changes in the resting firing rate of vestibular afferents and, consequently, vestibular nuclei neurons; (2) the most irregularly firing primary otolith afferents that are most sensitive to labyrinthine electrical stimulation might contribute to reflex dynamics and sensitivity; (3) inputs from both labyrinths are necessary for the generation of the translational VORs.

Repertoires of Cultural Practices for Enacting Play and Learning in a Playgroup

ERIC Educational Resources Information Center

Fleer, Marilyn; Hammer, Marie

2014-01-01

Variations in cultural practices between families and schools have emerged as central to many studies (Rogoff, 2003) and these dynamic variations have been named as "repertoires" of cultural practice (Gutierrez & Rogoff, 2003). Emerging from this literature has been a recognition of the dynamic tension between the cultural practices…

UAB UTC domain 2 : development of a dynamic traffic assignment and simulation model for incident and emergency management applications in the Birmingham Region (Aim 1).

DOT National Transportation Integrated Search

2010-12-01

A number of initiatives were undertaken to support education, training, and technology transfer objectives related to UAB UTC Domain 2 Project: Development of a Dynamic Traffic Assignment and Simulation Model for Incident and Emergency Management App...

Emerging Trends in Science Education in a Dynamic Academic Environment

ERIC Educational Resources Information Center

Avwiri, H. E.

2016-01-01

Emerging Trends in Science Education in a Dynamic Academic Environment highlights the changes that have occurred in science education particularly in institutions of higher learning in southern Nigeria. Impelled by the fact that most Nigerian Universities and Colleges of Education still adhere to the practices and teaching methodologies of the…

Dynamic equilibrium strategy for drought emergency temporary water transfer and allocation management

NASA Astrophysics Data System (ADS)

Xu, Jiuping; Ma, Ning; Lv, Chengwei

2016-08-01

Efficient water transfer and allocation are critical for disaster mitigation in drought emergencies. This is especially important when the different interests of the multiple decision makers and the fluctuating water resource supply and demand simultaneously cause space and time conflicts. To achieve more effective and efficient water transfers and allocations, this paper proposes a novel optimization method with an integrated bi-level structure and a dynamic strategy, in which the bi-level structure works to deal with space dimension conflicts in drought emergencies, and the dynamic strategy is used to deal with time dimension conflicts. Combining these two optimization methods, however, makes calculation complex, so an integrated interactive fuzzy program and a PSO-POA are combined to develop a hybrid-heuristic algorithm. The successful application of the proposed model in a real world case region demonstrates its practicality and efficiency. Dynamic cooperation between multiple reservoirs under the coordination of a global regulator reflects the model's efficiency and effectiveness in drought emergency water transfer and allocation, especially in a fluctuating environment. On this basis, some corresponding management recommendations are proposed to improve practical operations.

Diffusion Geometry Unravels the Emergence of Functional Clusters in Collective Phenomena.

PubMed

De Domenico, Manlio

2017-04-21

Collective phenomena emerge from the interaction of natural or artificial units with a complex organization. The interplay between structural patterns and dynamics might induce functional clusters that, in general, are different from topological ones. In biological systems, like the human brain, the overall functionality is often favored by the interplay between connectivity and synchronization dynamics, with functional clusters that do not coincide with anatomical modules in most cases. In social, sociotechnical, and engineering systems, the quest for consensus favors the emergence of clusters. Despite the unquestionable evidence for mesoscale organization of many complex systems and the heterogeneity of their interconnectivity, a way to predict and identify the emergence of functional modules in collective phenomena continues to elude us. Here, we propose an approach based on random walk dynamics to define the diffusion distance between any pair of units in a networked system. Such a metric allows us to exploit the underlying diffusion geometry to provide a unifying framework for the intimate relationship between metastable synchronization, consensus, and random search dynamics in complex networks, pinpointing the functional mesoscale organization of synthetic and biological systems.

Diffusion Geometry Unravels the Emergence of Functional Clusters in Collective Phenomena

NASA Astrophysics Data System (ADS)

De Domenico, Manlio

2017-04-01

Collective phenomena emerge from the interaction of natural or artificial units with a complex organization. The interplay between structural patterns and dynamics might induce functional clusters that, in general, are different from topological ones. In biological systems, like the human brain, the overall functionality is often favored by the interplay between connectivity and synchronization dynamics, with functional clusters that do not coincide with anatomical modules in most cases. In social, sociotechnical, and engineering systems, the quest for consensus favors the emergence of clusters. Despite the unquestionable evidence for mesoscale organization of many complex systems and the heterogeneity of their interconnectivity, a way to predict and identify the emergence of functional modules in collective phenomena continues to elude us. Here, we propose an approach based on random walk dynamics to define the diffusion distance between any pair of units in a networked system. Such a metric allows us to exploit the underlying diffusion geometry to provide a unifying framework for the intimate relationship between metastable synchronization, consensus, and random search dynamics in complex networks, pinpointing the functional mesoscale organization of synthetic and biological systems.

Dynamics of representational change: entropy, action, and cognition.

PubMed

Stephen, Damian G; Dixon, James A; Isenhower, Robert W

2009-12-01

Explaining how the cognitive system can create new structures has been a major challenge for cognitive science. Self-organization from the theory of nonlinear dynamics offers an account of this remarkable phenomenon. Two studies provide an initial test of the hypothesis that the emergence of new cognitive structure follows the same universal principles as emergence in other domains (e.g., fluids, lasers). In both studies, participants initially solved gear-system problems by manually tracing the force across a system of gears. Subsequently, they discovered that the gears form an alternating sequence, thereby demonstrating a new cognitive structure. In both studies, dynamical analyses of action during problem solving predicted the spontaneous emergence of the new cognitive structure. Study 1 showed that a peak in entropy, followed by negentropy, key indicators of self-organization, predicted discovery of alternation. Study 2 replicated these effects, and showed that increasing environmental entropy accelerated discovery, a classic prediction from dynamics. Additional analyses based on the relationship between phase transitions and power-law behavior provide converging evidence. The studies provide an initial demonstration of the emergence of cognitive structure through self-organization.

The ups and downs of trophic control in continental shelf ecosystems.

PubMed

Frank, Kenneth T; Petrie, Brian; Shackell, Nancy L

2007-05-01

Traditionally, marine ecosystem structure was thought to be determined by phytoplankton dynamics. However, an integrated view on the relative roles of top-down (consumer-driven) and bottom-up (resource-driven) forcing in large-scale, exploited marine ecosystems is emerging. Long time series of scientific survey data, underpinning the management of commercially exploited species such as cod, are being used to diagnose mechanisms that could affect the composition and relative abundance of species in marine food webs. By assembling published data from studies in exploited North Atlantic ecosystems, we found pronounced geographical variation in top-down and bottom-up trophic forcing. The data suggest that ecosystem susceptibility to top-down control and their resiliency to exploitation are related to species richness and oceanic temperature conditions. Such knowledge could be used to produce ecosystem guidelines to regulate and manage fisheries in a sustainable fashion.

Understanding soft glassy materials using an energy landscape approach

NASA Astrophysics Data System (ADS)

Hwang, Hyun Joo; Riggleman, Robert A.; Crocker, John C.

2016-09-01

Many seemingly different soft materials--such as soap foams, mayonnaise, toothpaste and living cells--display strikingly similar viscoelastic behaviour. A fundamental physical understanding of such soft glassy rheology and how it can manifest in such diverse materials, however, remains unknown. Here, by using a model soap foam consisting of compressible spherical bubbles, whose sizes slowly evolve and whose collective motion is simply dictated by energy minimization, we study the foam's dynamics as it corresponds to downhill motion on an energy landscape function spanning a high-dimensional configuration space. We find that these downhill paths, when viewed in this configuration space, are, surprisingly, fractal. The complex behaviour of our model, including power-law rheology and non-diffusive bubble motion and avalanches, stems directly from the fractal dimension and energy function of these paths. Our results suggest that ubiquitous soft glassy rheology may be a consequence of emergent fractal geometry in the energy landscapes of many complex fluids.

A moving view: subcellular trafficking processes in pattern recognition receptor-triggered plant immunity.

PubMed

Ben Khaled, Sara; Postma, Jelle; Robatzek, Silke

2015-01-01

A significant challenge for plants is to induce localized defense responses at sites of pathogen attack. Therefore, host subcellular trafficking processes enable accumulation and exchange of defense compounds, which contributes to the plant on-site defenses in response to pathogen perception. This review summarizes our current understanding of the transport processes that facilitate immunity, the significance of which is highlighted by pathogens reprogramming membrane trafficking through host cell translocated effectors. Prominent immune-related cargos of plant trafficking pathways are the pattern recognition receptors (PRRs), which must be present at the plasma membrane to sense microbes in the apoplast. We focus on the dynamic localization of the FLS2 receptor and discuss the pathways that regulate receptor transport within the cell and their link to FLS2-mediated immunity. One emerging theme is that ligand-induced late endocytic trafficking is conserved across different PRR protein families as well as across different plant species.

Transcription and recombination: when RNA meets DNA.

PubMed

Aguilera, Andrés; Gaillard, Hélène

2014-08-01

A particularly relevant phenomenon in cell physiology and proliferation is the fact that spontaneous mitotic recombination is strongly enhanced by transcription. The most accepted view is that transcription increases the occurrence of double-strand breaks and/or single-stranded DNA gaps that are repaired by recombination. Most breaks would arise as a consequence of the impact that transcription has on replication fork progression, provoking its stalling and/or breakage. Here, we discuss the mechanisms responsible for the cross talk between transcription and recombination, with emphasis on (1) the transcription-replication conflicts as the main source of recombinogenic DNA breaks, and (2) the formation of cotranscriptional R-loops as a major cause of such breaks. The new emerging questions and perspectives are discussed on the basis of the interference between transcription and replication, as well as the way RNA influences genome dynamics. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Quantum-Inspired Multidirectional Associative Memory With a Self-Convergent Iterative Learning.

PubMed

Masuyama, Naoki; Loo, Chu Kiong; Seera, Manjeevan; Kubota, Naoyuki

2018-04-01

Quantum-inspired computing is an emerging research area, which has significantly improved the capabilities of conventional algorithms. In general, quantum-inspired hopfield associative memory (QHAM) has demonstrated quantum information processing in neural structures. This has resulted in an exponential increase in storage capacity while explaining the extensive memory, and it has the potential to illustrate the dynamics of neurons in the human brain when viewed from quantum mechanics perspective although the application of QHAM is limited as an autoassociation. We introduce a quantum-inspired multidirectional associative memory (QMAM) with a one-shot learning model, and QMAM with a self-convergent iterative learning model (IQMAM) based on QHAM in this paper. The self-convergent iterative learning enables the network to progressively develop a resonance state, from inputs to outputs. The simulation experiments demonstrate the advantages of QMAM and IQMAM, especially the stability to recall reliability.

Beyond mechanistic interaction: value-based constraints on meaning in language.

PubMed

Rączaszek-Leonardi, Joanna; Nomikou, Iris

2015-01-01

According to situated, embodied, and distributed approaches to cognition, language is a crucial means for structuring social interactions. Recent approaches that emphasize this coordinative function treat language as a system of replicable constraints on individual and interactive dynamics. In this paper, we argue that the integration of the replicable-constraints approach to language with the ecological view on values allows for a deeper insight into processes of meaning creation in interaction. Such a synthesis of these frameworks draws attention to important sources of structuring interactions beyond the sheer efficiency of a collective system in its current task situation. Most importantly, the workings of linguistic constraints will be shown as embedded in more general fields of values, which are realized on multiple timescales. Because the ontogenetic timescale offers a convenient window into the emergence of linguistic constraints, we present illustrations of concrete mechanisms through which values may become embodied in language use in development.

Chromatin Insulators and Topological Domains: Adding New Dimensions to 3D Genome Architecture

PubMed Central

Matharu, Navneet K.; Ahanger, Sajad H.

2015-01-01

The spatial organization of metazoan genomes has a direct influence on fundamental nuclear processes that include transcription, replication, and DNA repair. It is imperative to understand the mechanisms that shape the 3D organization of the eukaryotic genomes. Chromatin insulators have emerged as one of the central components of the genome organization tool-kit across species. Recent advancements in chromatin conformation capture technologies have provided important insights into the architectural role of insulators in genomic structuring. Insulators are involved in 3D genome organization at multiple spatial scales and are important for dynamic reorganization of chromatin structure during reprogramming and differentiation. In this review, we will discuss the classical view and our renewed understanding of insulators as global genome organizers. We will also discuss the plasticity of chromatin structure and its re-organization during pluripotency and differentiation and in situations of cellular stress. PMID:26340639

Systems thinking.

PubMed

Cabrera, Derek; Colosi, Laura; Lobdell, Claire

2008-08-01

Evaluation is one of many fields where "systems thinking" is popular and is said to hold great promise. However, there is disagreement about what constitutes systems thinking. Its meaning is ambiguous, and systems scholars have made diverse and divergent attempts to describe it. Alternative origins include: von Bertalanffy, Aristotle, Lao Tsu or multiple aperiodic "waves." Some scholars describe it as synonymous with systems sciences (i.e., nonlinear dynamics, complexity, chaos). Others view it as taxonomy-a laundry list of systems approaches. Within so much noise, it is often difficult for evaluators to find the systems thinking signal. Recent work in systems thinking describes it as an emergent property of four simple conceptual patterns (rules). For an evaluator to become a "systems thinker", he or she need not spend years learning many methods or nonlinear sciences. Instead, with some practice, one can learn to apply these four simple rules to existing evaluation knowledge with transformative results.

Expressions of machismo in colorectal cancer screening among New Mexico Hispanic subpopulations.

PubMed

Getrich, Christina M; Sussman, Andrew L; Helitzer, Deborah L; Hoffman, Richard M; Warner, Teddy D; Sánchez, Victoria; Solares, Angélica; Rhyne, Robert L

2012-04-01

Although national colorectal cancer (CRC) incidence rates have steadily decreased, the rate for New Mexico Hispanics has been increasing, and screening rates are low. We conducted an exploratory qualitative study to determine barriers to CRC screening for New Mexico Hispanics. We found that machismo served as a dynamic influence on men's health-seeking behaviors; however, it was conceptualized differently by two distinct Hispanic subpopulations, and therefore appeared to play a different role in shaping their screening attitudes and behaviors. Machismo emerged as more of an influence for Mexican men, who expressed concern over colonoscopies being potentially transformative and/or stigmatizing, but was not as salient for Hispanos, who viewed the colonoscopy as "strictly medical," and were more concerned with discomfort and pain. Findings from the study highlight the importance of identifying varying characteristics among subpopulations to better understand screening barriers and provide optimal CRC screening counseling in primary care settings.

Expressions of Machismo in Colorectal Cancer Screening Among New Mexico Hispanic Subpopulations

PubMed Central

Getrich, Christina M.; Sussman, Andrew L.; Helitzer, Deborah L.; Hoffman, Richard M.; Warner, Teddy D.; Sánchez, Victoria; Solares, Angélica; Rhyne, Robert L.

2013-01-01

Although national colorectal cancer (CRC) incidence rates have steadily decreased, the rate for New Mexico Hispanics has been increasing and screening rates are low. We conducted an exploratory qualitative study to determine barriers to CRC screening for New Mexico Hispanics. We found that machismo served as a dynamic influence on men’s health seeking behaviors; however, it was conceptualized differently by two distinct Hispanic subpopulations and therefore appeared to play a different role in shaping their screening attitudes and behaviors. Machismo emerged as more of an influence for Mexican men, who expressed concern over colonoscopies being potentially transformative and/or stigmatizing, but was not as salient for Hispanos, who viewed the colonoscopy as “strictly medical” and were more concerned with discomfort and pain. This study highlights the importance of identifying varying characteristics among subpopulations to better understand screening barriers and provide optimal CRC screening counseling in primary care settings. PMID:22138258

Critical Theory and Teaching Literacy.

ERIC Educational Resources Information Center

King, James R.

A broad base for understanding what critical literacy is can be created by understanding three views of critical theory: critical social theory, feminist theory, and child advocacy. When each is brought to bear on the schooling rituals associated with literacy instruction, interesting commonalities among the three views emerge. Critical approaches…

13. DETAIL VIEW, OF TAINTER GATE PIER, SHOWING RECESSES FOR ...

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

13. DETAIL VIEW, OF TAINTER GATE PIER, SHOWING RECESSES FOR EMERGENCY BULKHEADS AND DOGGING DEVICES, LOOKING SOUTHEAST (DOWN FACE). UPSTREAM FACE OF TAINTER GATE IS VISIBLE IN UPPER RIGHT CORNER - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

An Emergent Framework: Views of Mathematical Processes

ERIC Educational Resources Information Center

Sanchez, Wendy B.; Lischka, Alyson E.; Edenfield, Kelly W.; Gammill, Rebecca

2015-01-01

The findings reported in this paper were generated from a case study of teacher leaders at a state-level mathematics conference. Investigation focused on how participants viewed the mathematical processes of communication, connections, representations, problem solving, and reasoning and proof. Purposeful sampling was employed to select nine…

The dynamics of team cognition: A process-oriented theory of knowledge emergence in teams.

PubMed

Grand, James A; Braun, Michael T; Kuljanin, Goran; Kozlowski, Steve W J; Chao, Georgia T

2016-10-01

Team cognition has been identified as a critical component of team performance and decision-making. However, theory and research in this domain continues to remain largely static; articulation and examination of the dynamic processes through which collectively held knowledge emerges from the individual- to the team-level is lacking. To address this gap, we advance and systematically evaluate a process-oriented theory of team knowledge emergence. First, we summarize the core concepts and dynamic mechanisms that underlie team knowledge-building and represent our theory of team knowledge emergence (Step 1). We then translate this narrative theory into a formal computational model that provides an explicit specification of how these core concepts and mechanisms interact to produce emergent team knowledge (Step 2). The computational model is next instantiated into an agent-based simulation to explore how the key generative process mechanisms described in our theory contribute to improved knowledge emergence in teams (Step 3). Results from the simulations demonstrate that agent teams generate collectively shared knowledge more effectively when members are capable of processing information more efficiently and when teams follow communication strategies that promote equal rates of information sharing across members. Lastly, we conduct an empirical experiment with real teams participating in a collective knowledge-building task to verify that promoting these processes in human teams also leads to improved team knowledge emergence (Step 4). Discussion focuses on implications of the theory for examining team cognition processes and dynamics as well as directions for future research. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

What Does It Take to Produce Interpretation? Informational, Peircean, and Code-Semiotic Views on Biosemiotics

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

Brier, Soren; Joslyn, Cliff A.

2013-04-01

This paper presents a critical analysis of code-semiotics, which we see as the latest attempt to create paradigmatic foundation for solving the question of the emergence of life and consciousness. We view code semiotics as a an attempt to revise the empirical scientific Darwinian paradigm, and to go beyond the complex systems, emergence, self-organization, and informational paradigms, and also the selfish gene theory of Dawkins and the Peircean pragmaticist semiotic theory built on the simultaneous types of evolution. As such it is a new and bold attempt to use semiotics to solve the problems created by the evolutionary paradigm’s commitmentmore » to produce a theory of how to connect the two sides of the Cartesian dualistic view of physical reality and consciousness in a consistent way.« less

20. TUNNEL JUNCTION. STACKED EMERGENCY FOOD RATIONS AT LEFT. LAUNCH ...

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

20. TUNNEL JUNCTION. STACKED EMERGENCY FOOD RATIONS AT LEFT. LAUNCH CONTROL CAPSULE BLAST DOOR AT CENTER. VIEW TO NORTHEAST. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

Neuromechanics: an integrative approach for understanding motor control.

PubMed

Nishikawa, Kiisa; Biewener, Andrew A; Aerts, Peter; Ahn, Anna N; Chiel, Hillel J; Daley, Monica A; Daniel, Thomas L; Full, Robert J; Hale, Melina E; Hedrick, Tyson L; Lappin, A Kristopher; Nichols, T Richard; Quinn, Roger D; Satterlie, Richard A; Szymik, Brett

2007-07-01

Neuromechanics seeks to understand how muscles, sense organs, motor pattern generators, and brain interact to produce coordinated movement, not only in complex terrain but also when confronted with unexpected perturbations. Applications of neuromechanics include ameliorating human health problems (including prosthesis design and restoration of movement following brain or spinal cord injury), as well as the design, actuation and control of mobile robots. In animals, coordinated movement emerges from the interplay among descending output from the central nervous system, sensory input from body and environment, muscle dynamics, and the emergent dynamics of the whole animal. The inevitable coupling between neural information processing and the emergent mechanical behavior of animals is a central theme of neuromechanics. Fundamentally, motor control involves a series of transformations of information, from brain and spinal cord to muscles to body, and back to brain. The control problem revolves around the specific transfer functions that describe each transformation. The transfer functions depend on the rules of organization and operation that determine the dynamic behavior of each subsystem (i.e., central processing, force generation, emergent dynamics, and sensory processing). In this review, we (1) consider the contributions of muscles, (2) sensory processing, and (3) central networks to motor control, (4) provide examples to illustrate the interplay among brain, muscles, sense organs and the environment in the control of movement, and (5) describe advances in both robotics and neuromechanics that have emerged from application of biological principles in robotic design. Taken together, these studies demonstrate that (1) intrinsic properties of muscle contribute to dynamic stability and control of movement, particularly immediately after perturbations; (2) proprioceptive feedback reinforces these intrinsic self-stabilizing properties of muscle; (3) control systems must contend with inevitable time delays that can simplify or complicate control; and (4) like most animals under a variety of circumstances, some robots use a trial and error process to tune central feedforward control to emergent body dynamics.

Identifying Potential Implications of Technologies on Military and Security Options

DTIC Science & Technology

2006-06-01

Technology Readiness Level (TRL) ratings. THE DISCUSSION Technology surprise occurs through the use of rapidly-emerging and disruptive technologies by...NATO RTB Systems Analysis and Studies Panel, Exploratory Team on the Impact of Disruptive Technologies The objectives of this task group (TG...Workshop on Emerging Disruptive Technologies and the Implications for Defence advanced the view that TTCP should examine the potential of emerging

Emergency radiology today between philosophy of science and the reality of "emergency care".

PubMed

Romano, L; Scaglione, M; Rotondo, A

2006-03-01

In the past 20 years, emergency care concept has substantially changed on a cultural point of view, going well beyond the boundaries of medical science. It is now a general understanding that the real enemy of the critical patient is time; thus, functional organisation and collocation of human and technological resources in the emergency department (ED) can help avoid the loss of human lives. This "cultural revolution" led to the creation and development of structural and organisational models (layouts) of EDs. Now, emergency radiology has a central role in ED organisation, and the radiologist, providing 24-h coverage in the emergency room, is crucial for the correct diagnostic approach and rapid management of trauma. If this is the cultural background to the "emergency care" concept, an overview of such care in our country shows great differences from a structural, technological and organisational point of view. The presence of the radiologist providing 24-h coverage in the emergency room is still uncommon in many EDs The qualification of emergency care must be sought by studying the needs of the population and by seeking qualified personnel with high professional skill levels. All this must be understood and pursued by politicians and health care managers whose aim should be to coordinate and check the measures and human resources applied to the system. This process necessarily involves rewarding those health care professionals who prove to be up to the job.

An embodied view of octopus neurobiology.

PubMed

Hochner, Binyamin

2012-10-23

Octopuses have a unique flexible body and unusual morphology, but nevertheless they are undoubtedly a great evolutionary success. They compete successfully with vertebrates in their ecological niche using a rich behavioral repertoire more typical of an intelligent predator which includes extremely effective defensive behavior--fast escape swimming and an astonishing ability to adapt their shape and color to their environment. The most obvious characteristic feature of an octopus is its eight long and flexible arms, but these pose a great challenge for achieving the level of motor and sensory information processing necessary for their behaviors. First, coordinating motion is a formidable task because of the infinite degrees of freedom that have to be controlled; and second, it is hard to use body coordinates in this flexible animal to represent sensory information in a central control system. Here I will review experimental results suggesting that these difficulties, arising from the animal's morphology, have imposed the evolution of unique brain/body/behavior relationships best explained as intelligent behavior which emerges from the octopus's embodied organization. The term 'intelligent embodiment' comes from robotics and refers to an approach to designing autonomous robots in which the behavior emerges from the dynamic physical and sensory interactions of the agent's materials, morphology and environment. Consideration of the unusual neurobiology of the octopus in the light of its unique morphology suggests that similar embodied principles are instrumental for understanding the emergence of intelligent behavior in all biological systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multi-omics Frontiers in Algal Research: Techniques and Progress to Explore Biofuels in the Postgenomics World.

PubMed

Rai, Vineeta; Karthikaichamy, Anbarasu; Das, Debasish; Noronha, Santosh; Wangikar, Pramod P; Srivastava, Sanjeeva

2016-07-01

Current momentum of microalgal research rests extensively in tapping the potential of multi-omics methodologies in regard to sustainable biofuels. Microalgal biomass is fermented to bioethanol; while lipids, particularly triacylglycerides (TAGs), are transesterified to biodiesels. Biodiesel has emerged as an ideal biofuel candidate; hence, its commercialization and use are increasingly being emphasized. Abiotic stresses exaggerate TAG accumulation, but the precise mechanisms are yet to be known. More recently, comprehensive multi-omics studies in microalgae have emerged from the biofuel perspective. Genomics and transcriptomics of microalgae have provided crucial leads and basic understanding toward lipid biosynthesis. Proteomics and metabolomics are now complementing "algal omics" and offer precise functional insights into the attendant static and dynamic physiological contexts. Indeed, the field has progressed from shotgun to targeted approaches. Notably, targeted proteomics studies in microalga are not yet reported. Several multi-omics tools and technologies that may be used to dig deeper into the microalgal physiology are examined and highlighted in this review. The article therefore aims to both introduce various available high-throughput biotechnologies and applications of "omics" in microalgae, and enlists a compendium of the emerging cutting edge literature. We suggest that a strategic and thoughtful combination of data streams from different omics platforms can provide a system-wide overview. The algal omics warrants closer attention in the future, with a view to technical, economic, and societal impacts that are anticipated in the current postgenomics era.

Students' Views About Potentially Offering Physics Courses Online

NASA Astrophysics Data System (ADS)

Ramlo, Susan E.

2016-06-01

Nationally, many public universities have started to move into the online course and program market that is most often associated with for-profit institutions of higher education. Administrators in public universities make statements regarding benefits to students' desire for flexibility and profit margins related to online courses. But do students attending a large public university want to take courses online especially science courses perceived to be difficult such as freshmen-level physics courses? This study took place at a large, public, Midwestern university and involved students enrolled in the first semester of a face-to-face, flipped physics course for engineering technology majors. Statements were collected from comments about online courses made by the university's administration and students in the course. Twenty students sorted 45 statements. Two student views emerged with one rejecting online courses in general and the other primarily rejecting online math, science, and technology courses, including physics. Students' descriptions of their previous online course experiences were used to inform the analyses and to assist in describing the two views that emerged in conjunction with the distinguishing statements. Consensus among the two views is also discussed. Overall, the results indicate a potential divergence between student views and what university administrators believe students want.

Seeing is (Not) Believing: How Viewing Pornography Shapes the Religious Lives of Young Americans

PubMed Central

Perry, Samuel L.; Hayward, George M.

2017-01-01

Pornography has become increasingly accessible in the United States, and particularly for younger Americans. While some research considers how pornography use affects the sexual and psychological health of adolescents and emerging adults, sociologists have given little attention to how viewing pornography may shape young Americans’ connection to key social and cultural institutions, like religion. This article examines whether viewing pornography may actually have a secularizing effect, reducing young Americans’ personal religiosity over time. To test for this, we use data from three waves of the National Study of Youth and Religion. Fixed-effects regression models show that more frequent pornography viewing diminishes religious service attendance, importance of religious faith, prayer frequency, and perceived closeness to God, while increasing religious doubts. These effects hold regardless of gender. The effects of viewing pornography on importance of faith, closeness to God, and religious doubts are stronger for teenagers compared to emerging adults. In light of the rapidly growing availability and acceptance of pornography for young Americans, our findings suggest that scholars must consider how increasingly pervasive pornography consumption may shape both the religious lives of young adults and also the future landscape of American religion more broadly. PMID:28546649

46. View of end bay of NW corner of mill ...

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

46. View of end bay of NW corner of mill ruins showing where flue emerged from area of Jamaican Train. - Hacienda Azurarera Santa Elena, Sugar Mill Ruins, 1.44 miles North of PR Route 2 Bridge Over Rio De La Plata, Toa Baja, Toa Baja Municipio, PR

The Hidden Curriculum in Distance Education: An Updated View.

ERIC Educational Resources Information Center

Anderson, Terry

2001-01-01

Addressing recent criticism of distance education, explores the distinctive hidden curriculum (supposed "real" agenda) of distance education, focusing on both its positive and negative expressions. Also offers an updated view of the hidden curriculum of traditional, campus-based education, grounded in an emerging worldwide context of broadening…

Modern and Postmodern Career Theories: The Unnecessary Divorce

ERIC Educational Resources Information Center

Sampson, James P., Jr.

2009-01-01

Postmodern approaches to career counseling are becoming increasingly popular. Part of the impetus for the postmodern view has involved perceived problems in the assumptions and application of the modern approach. Two points of view have emerged: (a) the modern and postmodern approaches are incompatible, and the postmodern approach is superior to…

20. DETaIL VIEW OF UPPER EAST WALL CONTROL STATION, SHOWING ...

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

20. DETaIL VIEW OF UPPER EAST WALL CONTROL STATION, SHOWING EMERGENCY BULKHEAD STIFFLEG DERRICK, MAIN LOCK PEDESTRIAN BRIDGE, RECESSES FOR MAIN LOCK LIFT GATE, AND TILE GAUGES, LOOKING SOUTHEAST - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

20. VIEW, LOOKING SOUTH, SHOWING ONE OF TWO MAIN ELECTRIC ...

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

20. VIEW, LOOKING SOUTH, SHOWING ONE OF TWO MAIN ELECTRIC MOTORS IN FOREGROUND WITH REDUCTION GEAR HOUSING AT RIGHT, GASOLINE- POWERED WAUKESHA AUXILIARY DRIVE MOTOR AT MIDDLE, AND GASOLINE- POWERED EMERGENCY GENERATOR IN BACKGROUND - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

Students' Views on the Effectiveness of Motivational Interviewing for Challenging Disaffection

ERIC Educational Resources Information Center

Snape, Laura; Atkinson, Cathy

2017-01-01

Emerging evidence suggests motivational interviewing (MI) is an effective intervention for supporting disaffected students. However, previous literature has failed to establish students' views on MI. In the present study, three students took part in an individual MI intervention, delivered by three educational psychologists (EPs). Self-report…

From Epistemology to Ecopolitics: Renewing a Paradigm for Curriculum.

ERIC Educational Resources Information Center

Gough, Noel

1989-01-01

Contrasts the epistemological world view of education found in Western industrialized societies with an emerging ecopolitical view which is based in an Aristotelian moral universe. Points out that reforms may affect procedures and practices without altering purposes and values. Suggests that these traditions should be transcended in order to gain…

29 CFR 4.123 - Administrative limitations, variances, tolerances, and exemptions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... which the contract services are to be provided, the views of such office on the matter should be... channels to the agency headquarters for submission with the latter's views to the Administrator of the Wage... for unexpected contingencies or emergency situations such as illness, or accident; and (3) Contracts...

34. VIEW OF THREE MONITORS LOCATED IMMEDIATELY WEST OF THOSE ...

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

34. VIEW OF THREE MONITORS LOCATED IMMEDIATELY WEST OF THOSE IN PHOTO A-33. TELEPHONE BELOW THE CENTER MONITOR IS LABLED 'ACCIDENT REPORTING EMERGENCY NOTIFICATION SYSTEM ONLY.' - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Establishing Conventional Communication Systems: Is Common Knowledge Necessary?

ERIC Educational Resources Information Center

Barr, Dale J.

2004-01-01

How do communities establish shared communication systems? The Common Knowledge view assumes that symbolic conventions develop through the accumulation of common knowledge regarding communication practices among the members of a community. In contrast with this view, it is proposed that coordinated communication emerges a by-product of local…

View of 175 ton hoisthouse from northeast. Hoist operator's cab ...

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

View of 175 ton hoist-house from northeast. Hoist operator's cab is in foreground center. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

View of first level from north showing interstitial structural columns ...

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

View of first level from north showing interstitial structural columns for the Shuttle assemble configuration. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

A Low-Cost PC-Based Image Workstation for Dynamic Interactive Display of Three-Dimensional Anatomy

NASA Astrophysics Data System (ADS)

Barrett, William A.; Raya, Sai P.; Udupa, Jayaram K.

1989-05-01

A system for interactive definition, automated extraction, and dynamic interactive display of three-dimensional anatomy has been developed and implemented on a low-cost PC-based image workstation. An iconic display is used for staging predefined image sequences through specified increments of tilt and rotation over a solid viewing angle. Use of a fast processor facilitates rapid extraction and rendering of the anatomy into predefined image views. These views are formatted into a display matrix in a large image memory for rapid interactive selection and display of arbitrary spatially adjacent images within the viewing angle, thereby providing motion parallax depth cueing for efficient and accurate perception of true three-dimensional shape, size, structure, and spatial interrelationships of the imaged anatomy. The visual effect is that of holding and rotating the anatomy in the hand.

New Evidence for Strategic Differences between Static and Dynamic Search Tasks: An Individual Observer Analysis of Eye Movements

PubMed Central

Dickinson, Christopher A.; Zelinsky, Gregory J.

2013-01-01

Two experiments are reported that further explore the processes underlying dynamic search. In Experiment 1, observers’ oculomotor behavior was monitored while they searched for a randomly oriented T among oriented L distractors under static and dynamic viewing conditions. Despite similar search slopes, eye movements were less frequent and more spatially constrained under dynamic viewing relative to static, with misses also increasing more with target eccentricity in the dynamic condition. These patterns suggest that dynamic search involves a form of sit-and-wait strategy in which search is restricted to a small group of items surrounding fixation. To evaluate this interpretation, we developed a computational model of a sit-and-wait process hypothesized to underlie dynamic search. In Experiment 2 we tested this model by varying fixation position in the display and found that display positions optimized for a sit-and-wait strategy resulted in higher d′ values relative to a less optimal location. We conclude that different strategies, and therefore underlying processes, are used to search static and dynamic displays. PMID:23372555

Boundaries as Mechanisms for Learning in Emergency Exercises with Students from Emergency Service Organisations

ERIC Educational Resources Information Center

Andersson, Annika

2016-01-01

To prepare emergency response organisations for collaborative work in unpredictable and dynamic situations, various types of exercises are widely used. Still, our knowledge of collaboration exercises with emergency response students is limited. This study aimed to contribute to this field by exploring boundaries that emerged between collaborating…

Children's views on research without prior consent in emergency situations: a UK qualitative study.

PubMed

Roper, Louise; Sherratt, Frances C; Young, Bridget; McNamara, Paul; Dawson, Angus; Appleton, Richard; Crawley, Esther; Frith, Lucy; Gamble, Carrol; Woolfall, Kerry

2018-06-09

We explored children's views on research without prior consent (RWPC) and sought to identify ways of involving children in research discussions. Qualitative interview study. Participants were recruited through a UK children's hospital and online advertising. 16 children aged 7-15 years with a diagnosis of asthma (n=14) or anaphylaxis (n=2) with recent (<12 months) experience of emergency care. Children were keen to be included in medical research and viewed RWPC as acceptable in emergency situations if trial interventions were judged safe. Children trusted that doctors would know about their trial participation and act in their best interests. All felt that children should be informed about the research following their recovery and involved in discussions with a clinician or their parent(s) about the use of data already collected as well as continued participation in the trial (if applicable). Participants suggested methods to inform children about their trial participation including an animation. Children supported, and were keen to be involved in, clinical trials in emergency situations. We present guidance and an animation that practitioners and parents might use to involve children in trial discussions following their recovery. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Dynamic Optical Filtration

NASA Technical Reports Server (NTRS)

Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

2005-01-01

A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

Dynamic optical filtration

NASA Technical Reports Server (NTRS)

Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

2005-01-01

A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

The mechanics of malaria parasite invasion of the human erythrocyte – towards a reassessment of the host cell contribution

PubMed Central

Koch, Marion

2016-01-01

Summary Despite decades of research, we still know little about the mechanics of Plasmodium host cell invasion. Fundamentally, while the essential or non‐essential nature of different parasite proteins is becoming clearer, their actual function and how each comes together to govern invasion are poorly understood. Furthermore, in recent years an emerging world view is shifting focus away from the parasite actin–myosin motor being the sole force responsible for entry to an appreciation of host cell dynamics and forces and their contribution to the process. In this review, we discuss merozoite invasion of the erythrocyte, focusing on the complex set of pre‐invasion events and how these might prime the red cell to facilitate invasion. While traditionally parasite interactions at this stage have been viewed simplistically as mediating adhesion only, recent work makes it apparent that by interacting with a number of host receptors and signalling pathways, combined with secretion of parasite‐derived lipid material, that the merozoite may initiate cytoskeletal re‐arrangements and biophysical changes in the erythrocyte that greatly reduce energy barriers for entry. Seen in this light Plasmodium invasion may well turn out to be a balance between host and parasite forces, much like that of other pathogen infection mechanisms. PMID:26663815

Language Multiplicity and Dynamism: Emergent Bilinguals Taking Ownership of Language Use in a Hybrid Curricular Space

ERIC Educational Resources Information Center

Martínez-Álvarez, Patricia

2017-01-01

This study explores the impact of hybrid instructional spaces on the purposeful and expansive use of translanguaging practices. Utilizing technology, the study explores the role of multimodality in bilinguals' language multiplicity and dynamism. The research addresses: (a) how do emergent bilinguals in dual language programs deploy their full…

2011 Quantum Control of Light & Matter Gordon Research Conference (July 31-August 5, 2011, Mount Holyoke College, South Hadley, MA)

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

Thomas Weinacht

2011-08-05

Quantum control of light and matter is the quest to steer a physical process to a desirable outcome, employing constructive and destructive interference. Three basic questions address feasibility of quantum control: (1) The problem of controllability, does a control field exist for a preset initial and target state; (2) Synthesis, constructively finding the field that leads to the target; and (3) Optimal Control Theory - optimizing the field that carries out this task. These continue to be the fundamental theoretical questions to be addressed in the conference. How to realize control fields in the laboratory is an ongoing challenge. Thismore » task is very diverse viewing the emergence of control scenarios ranging from attoseconds to microseconds. How do the experimental observations reflect on the theoretical framework? The typical arena of quantum control is an open environment where much of the control is indirect. How are control scenarios realized in dissipative open systems? Can new control opportunities emerge? Can one null decoherence effects? An ideal setting for control is ultracold matter. The initial and final state can be defined more precisely. Coherent control unifies many fields of physical science. A lesson learned in one field can reflect on another. Currently quantum information processing has emerged as a primary target of control where the key issue is controlling quantum gate operation. Modern nonlinear spectroscopy has emerged as another primary field. The challenge is to unravel the dynamics of molecular systems undergoing strong interactions with the environment. Quantum optics where non-classical fields are to be generated and employed. Finally, coherent control is the basis for quantum engineering. These issues will be under the limelight of the Gordon conference on Quantum Control of Light and Matter.« less

Emergency management in health: key issues and challenges in the UK.

PubMed

Lee, Andrew C K; Phillips, Wendy; Challen, Kirsty; Goodacre, Steve

2012-10-19

Emergency planning in the UK has grown considerably in recent years, galvanised by the threat of terrorism. However, deficiencies in NHS emergency planning were identified and the evidence-base that underpins it is questionable. Inconsistencies in terminologies and concepts also exist. Different models of emergency management exist internationally but the optimal system is unknown. This study examines the evidence-base and evidence requirements for emergency planning in the UK health context. The study involved semi-structured interviews with key stakeholders and opinion leaders. Purposive sampling was used to obtain a breadth of views from various agencies involved in emergency planning and response. Interviews were then analysed using a grounded approach using standard framework analysis techniques. We conducted 17 key informant interviews. Interviewees identified greater gaps in operational than technical aspects of emergency planning. Social and behavioural knowledge gaps were highlighted with regards to how individuals and organisations deal with risk and behave in emergencies. Evidence-based approaches to public engagement and for developing community resilience to disasters are lacking. Other gaps included how knowledge was developed and used. Conflicting views with regards to the optimal configuration and operation of the emergency management system were voiced. Four thematic categories for future research emerged:(i) Knowledge-base for emergency management: Further exploration is needed of how knowledge is acquired, valued, disseminated, adopted and retained.(ii) Social and behavioural issues: Greater understanding of how individuals approach risk and behave in emergencies is required.(iii) Organisational issues in emergencies: Several conflicting organisational issues were identified; value of planning versus plans, flexible versus standardized procedures, top-down versus bottom-up engagement, generic versus specific planning, and reactive versus proactive approaches to emergencies.(iv) Emergency management system: More study is required of system-wide issues relating to system configuration and operation, public engagement, and how emergency planning is assessed.

Self-organization via active exploration in robotic applications

NASA Technical Reports Server (NTRS)

Ogmen, H.; Prakash, R. V.

1992-01-01

We describe a neural network based robotic system. Unlike traditional robotic systems, our approach focussed on non-stationary problems. We indicate that self-organization capability is necessary for any system to operate successfully in a non-stationary environment. We suggest that self-organization should be based on an active exploration process. We investigated neural architectures having novelty sensitivity, selective attention, reinforcement learning, habit formation, flexible criteria categorization properties and analyzed the resulting behavior (consisting of an intelligent initiation of exploration) by computer simulations. While various computer vision researchers acknowledged recently the importance of active processes (Swain and Stricker, 1991), the proposed approaches within the new framework still suffer from a lack of self-organization (Aloimonos and Bandyopadhyay, 1987; Bajcsy, 1988). A self-organizing, neural network based robot (MAVIN) has been recently proposed (Baloch and Waxman, 1991). This robot has the capability of position, size rotation invariant pattern categorization, recognition and pavlovian conditioning. Our robot does not have initially invariant processing properties. The reason for this is the emphasis we put on active exploration. We maintain the point of view that such invariant properties emerge from an internalization of exploratory sensory-motor activity. Rather than coding the equilibria of such mental capabilities, we are seeking to capture its dynamics to understand on the one hand how the emergence of such invariances is possible and on the other hand the dynamics that lead to these invariances. The second point is crucial for an adaptive robot to acquire new invariances in non-stationary environments, as demonstrated by the inverting glass experiments of Helmholtz. We will introduce Pavlovian conditioning circuits in our future work for the precise objective of achieving the generation, coordination, and internalization of sequence of actions.

View of hydrodynamic support cylinders, removed from structure and relocated ...

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

View of hydrodynamic support cylinders, removed from structure and relocated for reconditioning to return them to service. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

Interior view of 175 ton hoist house looking at the ...

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

Interior view of 175 ton hoist house looking at the exterior casing for the wire rope spools. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

The Prescription Opioid Epidemic: Social Media Responses to the Residents' Perspective Article.

PubMed

Choo, Esther K; Mazer-Amirshahi, Maryann; Juurlink, David; Kobner, Scott; Scott, Kevin; Lin, Michelle

2016-01-01

In June 2014, Annals of Emergency Medicine collaborated with the Academic Life in Emergency Medicine (ALiEM) blog-based Web site to host an online discussion session featuring the Annals Residents' Perspective article "The Opioid Prescription Epidemic and the Role of Emergency Medicine" by Poon and Greenwood-Ericksen. This dialogue included a live videocast with the authors and other experts, a detailed discussion on the ALiEM Web site's comment section, and real-time conversations on Twitter. Engagement was tracked through various Web analytic tools, and themes were identified by content curation. The dialogue resulted in 1,262 unique page views from 433 cities in 41 countries on the ALiEM Web site, 408,498 Twitter impressions, and 168 views of the video interview with the authors. Four major themes about prescription opioids identified included the following: physician knowledge, inconsistent medical education, balance between overprescribing and effective pain management, and approaches to solutions. Free social media technologies provide a unique opportunity to engage with a diverse community of emergency medicine and non-emergency medicine clinicians, nurses, learners, and even patients. Such technologies may allow more rapid hypothesis generation for future research and more accelerated knowledge translation. Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Unified force-level theory of multiscale transient localization and emergent elasticity in polymer solutions and melts

NASA Astrophysics Data System (ADS)

Dell, Zachary E.; Schweizer, Kenneth S.

A unified, microscopic, theoretical understanding of polymer dynamics in concentrated liquids from segmental to macromolecular scales remains an open problem. We have formulated a statistical mechanical theory for this problem that explicitly accounts for intra- and inter-molecular forces at the Kuhn segment level. The theory is self-consistently closed at the level of a matrix of dynamical second moments of a tagged chain. Two distinct regimes of isotropic transient localization are predicted. In semidilute solutions, weak localization is predicted on a mesoscopic length scale between segment and chain scales which is a power law function of the invariant packing length. This is consistent with the breakdown of Rouse dynamics and the emergence of entanglements. The chain structural correlations in the dynamically arrested state are also computed. In dense melts, strong localization is predicted on a scale much smaller than the segment size which is weakly dependent on chain connectivity and signals the onset of glassy dynamics. Predictions of the dynamic plateau shear modulus are consistent with the known features of emergent rubbery and glassy elasticity. Generalizations to treat the effects of chemical crosslinking and physical bond formation in polymer gels are possible.

Staff Development and Total Quality Management.

ERIC Educational Resources Information Center

Norris, Gerald L.; Norris, Joye H.

Professional development is an emerging view of faculty development that places teachers in charge of their own professional growth. The emergence of Total Quality Management (TQM) provides a vehicle for designing professional development to meet the needs of individuals and the organizations that employ them. The eight tenets of Deming's theory…

Second Language Users and Emerging English Designs

ERIC Educational Resources Information Center

Jordan, Jay

2009-01-01

As English spreads as an international language, it evolves through diverse users' writing and speaking. However, traditional views of ESL users focus on their distance from fairly static notions of English-language competence. This research uses a grounded theory approach to describe a range of competencies that emerge in ESL users' interactions…

Emergent Readers' Social Interaction Styles and Their Comprehension Processes during Buddy Reading

ERIC Educational Resources Information Center

Christ, Tanya; Wang, X. Christine; Chiu, Ming Ming

2015-01-01

To examine the relations between emergent readers' social interaction styles and their comprehension processes, we adapted sociocultural and transactional views of learning and reading, and conducted statistical discourse analysis of 1,359 conversation turns transcribed from 14 preschoolers' 40 buddy reading events. Results show that interaction…

How and when do expert emergency physicians generate and evaluate diagnostic hypotheses? A qualitative study using head-mounted video cued-recall interviews.

PubMed

Pelaccia, Thierry; Tardif, Jacques; Triby, Emmanuel; Ammirati, Christine; Bertrand, Catherine; Dory, Valérie; Charlin, Bernard

2014-12-01

The ability to make a diagnosis is a crucial skill in emergency medicine. Little is known about the way emergency physicians reach a diagnosis. This study aims to identify how and when, during the initial patient examination, emergency physicians generate and evaluate diagnostic hypotheses. We carried out a qualitative research project based on semistructured interviews with emergency physicians. The interviews concerned management of an emergency situation during routine medical practice. They were associated with viewing the video recording of emergency situations filmed in an "own-point-of-view" perspective. The emergency physicians generated an average of 5 diagnostic hypotheses. Most of these hypotheses were generated before meeting the patient or within the first 5 minutes of the meeting. The hypotheses were then rank ordered within the context of a verification procedure based on identifying key information. These tasks were usually accomplished without conscious effort. No hypothesis was completely confirmed or refuted until the results of investigations were available. The generation and rank ordering of diagnostic hypotheses is based on the activation of cognitive processes, enabling expert emergency physicians to process environmental information and link it to past experiences. The physicians seemed to strive to avoid the risk of error by remaining aware of the possibility of alternative hypotheses as long as they did not have the results of investigations. Understanding the diagnostic process used by emergency physicians provides interesting ideas for training residents in a specialty in which the prevalence of reasoning errors leading to incorrect diagnoses is high. Copyright © 2014 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Angular declination and the dynamic perception of egocentric distance.

PubMed

Gajewski, Daniel A; Philbeck, John W; Wirtz, Philip W; Chichka, David

2014-02-01

The extraction of the distance between an object and an observer is fast when angular declination is informative, as it is with targets placed on the ground. To what extent does angular declination drive performance when viewing time is limited? Participants judged target distances in a real-world environment with viewing durations ranging from 36-220 ms. An important role for angular declination was supported by experiments showing that the cue provides information about egocentric distance even on the very first glimpse, and that it supports a sensitive response to distance in the absence of other useful cues. Performance was better at 220-ms viewing durations than for briefer glimpses, suggesting that the perception of distance is dynamic even within the time frame of a typical eye fixation. Critically, performance in limited viewing trials was better when preceded by a 15-s preview of the room without a designated target. The results indicate that the perception of distance is powerfully shaped by memory from prior visual experience with the scene. A theoretical framework for the dynamic perception of distance is presented. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Control algorithms for dynamic attenuators.

PubMed

Hsieh, Scott S; Pelc, Norbert J

2014-06-01

The authors describe algorithms to control dynamic attenuators in CT and compare their performance using simulated scans. Dynamic attenuators are prepatient beam shaping filters that modulate the distribution of x-ray fluence incident on the patient on a view-by-view basis. These attenuators can reduce dose while improving key image quality metrics such as peak or mean variance. In each view, the attenuator presents several degrees of freedom which may be individually adjusted. The total number of degrees of freedom across all views is very large, making many optimization techniques impractical. The authors develop a theory for optimally controlling these attenuators. Special attention is paid to a theoretically perfect attenuator which controls the fluence for each ray individually, but the authors also investigate and compare three other, practical attenuator designs which have been previously proposed: the piecewise-linear attenuator, the translating attenuator, and the double wedge attenuator. The authors pose and solve the optimization problems of minimizing the mean and peak variance subject to a fixed dose limit. For a perfect attenuator and mean variance minimization, this problem can be solved in simple, closed form. For other attenuator designs, the problem can be decomposed into separate problems for each view to greatly reduce the computational complexity. Peak variance minimization can be approximately solved using iterated, weighted mean variance (WMV) minimization. Also, the authors develop heuristics for the perfect and piecewise-linear attenuators which do not require a priori knowledge of the patient anatomy. The authors compare these control algorithms on different types of dynamic attenuators using simulated raw data from forward projected DICOM files of a thorax and an abdomen. The translating and double wedge attenuators reduce dose by an average of 30% relative to current techniques (bowtie filter with tube current modulation) without increasing peak variance. The 15-element piecewise-linear dynamic attenuator reduces dose by an average of 42%, and the perfect attenuator reduces dose by an average of 50%. Improvements in peak variance are several times larger than improvements in mean variance. Heuristic control eliminates the need for a prescan. For the piecewise-linear attenuator, the cost of heuristic control is an increase in dose of 9%. The proposed iterated WMV minimization produces results that are within a few percent of the true solution. Dynamic attenuators show potential for significant dose reduction. A wide class of dynamic attenuators can be accurately controlled using the described methods.

Static and dynamic views of visual cortical organization.

PubMed

Casagrande, Vivien A; Xu, Xiangmin; Sáry, Gyula

2002-01-01

Without the aid of modern techniques Cajal speculated that cells in the visual cortex were connected in circuits. From Cajal's time until fairly recently, the flow of information within the cells and circuits of visual cortex has been described as progressing from input to output, from sensation to action. In this chapter we argue that a paradigm shift in our concept of the visual cortical neuron is under way. The most important change in our view concerns the neuron's functional role. Visual cortical neurons do not have static functional signatures but instead function dynamically depending on the ongoing activity of the networks to which they belong. These networks are not merely top-down or bottom-up unidirectional transmission lines, but rather represent machinery that uses recurrent information and is dynamic and highly adaptable. With the advancement of technology for analyzing the conversations of multiple neurons at many levels in the visual system and higher resolution imaging, we predict that the paradigm shift will progress to the point where neurons are no longer viewed as independent processing units but as members of subsets of networks where their role is mapped in space-time coordinates in relationship to the other neuronal members. This view moves us far from Cajal's original views of the neuron. Nevertheless, we believe that understanding the basic morphology and wiring of networks will continue to contribute to our overall understanding of the visual cortex.

Information Security: A Scientometric Study of the Profile, Structure, and Dynamics of an Emerging Scholarly Specialty

ERIC Educational Resources Information Center

Olijnyk, Nicholas Victor

2014-01-01

The central aim of the current research is to explore and describe the profile, dynamics, and structure of the information security specialty. This study's objectives are guided by four research questions: 1. What are the salient features of information security as a specialty? 2. How has the information security specialty emerged and evolved from…

Solving the dynamic ambulance relocation and dispatching problem using approximate dynamic programming

PubMed Central

Schmid, Verena

2012-01-01

Emergency service providers are supposed to locate ambulances such that in case of emergency patients can be reached in a time-efficient manner. Two fundamental decisions and choices need to be made real-time. First of all immediately after a request emerges an appropriate vehicle needs to be dispatched and send to the requests’ site. After having served a request the vehicle needs to be relocated to its next waiting location. We are going to propose a model and solve the underlying optimization problem using approximate dynamic programming (ADP), an emerging and powerful tool for solving stochastic and dynamic problems typically arising in the field of operations research. Empirical tests based on real data from the city of Vienna indicate that by deviating from the classical dispatching rules the average response time can be decreased from 4.60 to 4.01 minutes, which corresponds to an improvement of 12.89%. Furthermore we are going to show that it is essential to consider time-dependent information such as travel times and changes with respect to the request volume explicitly. Ignoring the current time and its consequences thereafter during the stage of modeling and optimization leads to suboptimal decisions. PMID:25540476

Biological conservation law as an emerging functionality in dynamical neuronal networks.

PubMed

Podobnik, Boris; Jusup, Marko; Tiganj, Zoran; Wang, Wen-Xu; Buldú, Javier M; Stanley, H Eugene

2017-11-07

Scientists strive to understand how functionalities, such as conservation laws, emerge in complex systems. Living complex systems in particular create high-ordered functionalities by pairing up low-ordered complementary processes, e.g., one process to build and the other to correct. We propose a network mechanism that demonstrates how collective statistical laws can emerge at a macro (i.e., whole-network) level even when they do not exist at a unit (i.e., network-node) level. Drawing inspiration from neuroscience, we model a highly stylized dynamical neuronal network in which neurons fire either randomly or in response to the firing of neighboring neurons. A synapse connecting two neighboring neurons strengthens when both of these neurons are excited and weakens otherwise. We demonstrate that during this interplay between the synaptic and neuronal dynamics, when the network is near a critical point, both recurrent spontaneous and stimulated phase transitions enable the phase-dependent processes to replace each other and spontaneously generate a statistical conservation law-the conservation of synaptic strength. This conservation law is an emerging functionality selected by evolution and is thus a form of biological self-organized criticality in which the key dynamical modes are collective.

Biological conservation law as an emerging functionality in dynamical neuronal networks

PubMed Central

Podobnik, Boris; Tiganj, Zoran; Wang, Wen-Xu; Buldú, Javier M.

2017-01-01

Scientists strive to understand how functionalities, such as conservation laws, emerge in complex systems. Living complex systems in particular create high-ordered functionalities by pairing up low-ordered complementary processes, e.g., one process to build and the other to correct. We propose a network mechanism that demonstrates how collective statistical laws can emerge at a macro (i.e., whole-network) level even when they do not exist at a unit (i.e., network-node) level. Drawing inspiration from neuroscience, we model a highly stylized dynamical neuronal network in which neurons fire either randomly or in response to the firing of neighboring neurons. A synapse connecting two neighboring neurons strengthens when both of these neurons are excited and weakens otherwise. We demonstrate that during this interplay between the synaptic and neuronal dynamics, when the network is near a critical point, both recurrent spontaneous and stimulated phase transitions enable the phase-dependent processes to replace each other and spontaneously generate a statistical conservation law—the conservation of synaptic strength. This conservation law is an emerging functionality selected by evolution and is thus a form of biological self-organized criticality in which the key dynamical modes are collective. PMID:29078286

Beyond Re/Presentation: A Case for Updating the Epistemology of Schooling

ERIC Educational Resources Information Center

Biesta, Gert J. J.; Osberg, Deborah

2007-01-01

In this paper we wish to argue that despite strong challenges to representational epistemology in the last two centuries, modern schooling is still organised around a representational view of knowledge. This is the case despite teaching practices being modified to accommodate different views of knowledge that have emerged in the last two…

A common origin for immunity and digestion.

PubMed

Broderick, Nichole A

2015-01-01

Historically, the digestive and immune systems were viewed and studied as separate entities. However, there are remarkable similarities and shared functions in both nutrient acquisition and host defense. Here, I propose a common origin for both systems. This association provides a new prism for viewing the emergence and evolution of host defense mechanisms.

Credit PSR. This view shows the south and east facades ...

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

Credit PSR. This view shows the south and east facades of this concrete block facility as seen when looking northwest (320°). Note the outdoor emergency shower; the roof has lightning rods installed at corners - Jet Propulsion Laboratory Edwards Facility, Oxidizer Weigh & Storage Building, Edwards Air Force Base, Boron, Kern County, CA

Inferring the background traffic arrival process in the Internet.

PubMed

Hága, Péter; Csabai, István; Vattay, Gábor

2009-12-01

Phase transition has been found in many complex interactivity systems. Complex networks are not exception either but there are quite few real systems where we can directly understand the emergence of this nontrivial behavior from the microscopic view. In this paper, we present the emergence of the phase transition between the congested and uncongested phases of a network link. We demonstrate a method to infer the background traffic arrival process, which is one of the key state parameters of the Internet traffic. The traffic arrival process in the Internet has been investigated in several studies, since the recognition of its self-similar nature. The statistical properties of the traffic arrival process are very important since they are fundamental in modeling the dynamical behavior. Here, we demonstrate how the widely used packet train technique can be used to determine the main properties of the traffic arrival process. We show that the packet train dispersion is sensitive to the congestion on the network path. We introduce the packet train stretch as an order parameter to describe the phase transition between the congested and uncongested phases of the bottleneck link in the path. We find that the distribution of the background traffic arrival process can be determined from the average packet train dispersion at the critical point of the system.

2011 Space Weather Workshop to Be Held in April

NASA Astrophysics Data System (ADS)

Peltzer, Thomas

2011-04-01

The annual Space Weather Workshop will be held in Boulder, Colo., 26-29 April 2011. The workshop will bring customers, forecasters, commercial service providers, researchers, and government agencies together in a lively dialogue about space weather. The workshop will include 4 days of plenary sessions on a variety of topics, with poster sessions focusing on the Sun, interplanetary space, the magnetosphere, and the ionosphere. The conference will address the remarkably diverse impacts of space weather on today's technology. Highlights on this year's agenda will include presentations on space weather impacts on the Global Positioning System (GPS), the Solar Terrestrial Relations Observatory's (STEREO) mission milestone of a 360° view of the Sun, the latest from NASA's Solar Dynamics Observatory (SDO), and space weather impacts on emergency response by the Federal Emergency Management Agency (FEMA). Additionally, the vulnerabilities of satellites and the power grid to space weather will be addressed. Additional highlights will include the Commercial Space Weather Interest Group's (CSWIG) roundtable session and a presentation from the Office of the Federal Coordinator for Meteorology (OFCM). The CSWIG roundtable session on the growth of the space weather enterprise will feature distinguished panelists. As always, lively interaction between the audience and the panel is anticipated. The OFCM will present the National Space Weather Program's new strategic plan.

Predictable 'meta-mechanisms' emerge from feedbacks between transpiration and plant growth and cannot be simply deduced from short-term mechanisms.

PubMed

Tardieu, François; Parent, Boris

2017-06-01

Growth under water deficit is controlled by short-term mechanisms but, because of numerous feedbacks, the combination of these mechanisms over time often results in outputs that cannot be deduced from the simple inspection of individual mechanisms. It can be analysed with dynamic models in which causal relationships between variables are considered at each time-step, allowing calculation of outputs that are routed back to inputs for the next time-step and that can change the system itself. We first review physiological mechanisms involved in seven feedbacks of transpiration on plant growth, involving changes in tissue hydraulic conductance, stomatal conductance, plant architecture and underlying factors such as hormones or aquaporins. The combination of these mechanisms over time can result in non-straightforward conclusions as shown by examples of simulation outputs: 'over production of abscisic acid (ABA) can cause a lower concentration of ABA in the xylem sap ', 'decreasing root hydraulic conductance when evaporative demand is maximum can improve plant performance' and 'rapid root growth can decrease yield'. Systems of equations simulating feedbacks over numerous time-steps result in logical and reproducible emergent properties that can be viewed as 'meta-mechanisms' at plant level, which have similar roles as mechanisms at cell level. © 2016 John Wiley & Sons Ltd.

Beyond a series of security nets: Applying STAMP & STPA to port security

DOE PAGES

Williams, Adam D.

2015-11-17

Port security is an increasing concern considering the significant role of ports in global commerce and today’s increasingly complex threat environment. Current approaches to port security mirror traditional models of accident causality -- ‘a series of security nets’ based on component reliability and probabilistic assumptions. Traditional port security frameworks result in isolated and inconsistent improvement strategies. Recent work in engineered safety combines the ideas of hierarchy, emergence, control and communication into a new paradigm for understanding port security as an emergent complex system property. The ‘System-Theoretic Accident Model and Process (STAMP)’ is a new model of causality based on systemsmore » and control theory. The associated analysis process -- System Theoretic Process Analysis (STPA) -- identifies specific technical or procedural security requirements designed to work in coordination with (and be traceable to) overall port objectives. This process yields port security design specifications that can mitigate (if not eliminate) port security vulnerabilities related to an emphasis on component reliability, lack of coordination between port security stakeholders or economic pressures endemic in the maritime industry. As a result, this article aims to demonstrate how STAMP’s broader view of causality and complexity can better address the dynamic and interactive behaviors of social, organizational and technical components of port security.« less

Beyond a series of security nets: Applying STAMP & STPA to port security

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

Williams, Adam D.

Port security is an increasing concern considering the significant role of ports in global commerce and today’s increasingly complex threat environment. Current approaches to port security mirror traditional models of accident causality -- ‘a series of security nets’ based on component reliability and probabilistic assumptions. Traditional port security frameworks result in isolated and inconsistent improvement strategies. Recent work in engineered safety combines the ideas of hierarchy, emergence, control and communication into a new paradigm for understanding port security as an emergent complex system property. The ‘System-Theoretic Accident Model and Process (STAMP)’ is a new model of causality based on systemsmore » and control theory. The associated analysis process -- System Theoretic Process Analysis (STPA) -- identifies specific technical or procedural security requirements designed to work in coordination with (and be traceable to) overall port objectives. This process yields port security design specifications that can mitigate (if not eliminate) port security vulnerabilities related to an emphasis on component reliability, lack of coordination between port security stakeholders or economic pressures endemic in the maritime industry. As a result, this article aims to demonstrate how STAMP’s broader view of causality and complexity can better address the dynamic and interactive behaviors of social, organizational and technical components of port security.« less

View of 200ton derrick interior support beneath it's bull wheel ...

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

View of 200-ton derrick interior support beneath it's bull wheel and mast centerline from from southeast. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

View from second floor platform looking up at subsequent platforms. ...

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

View from second floor platform looking up at subsequent platforms. Note the Shuttle assembly outlined by the platform edges. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

Detail view of fourth level platform winch used to lift ...

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

Detail view of fourth level platform winch used to lift platform segments away from the Shuttle assembly during testing. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

Dynamic Factor Analysis of Nonstationary Multivariate Time Series.

ERIC Educational Resources Information Center

Molenaar, Peter C. M.; And Others

1992-01-01

The dynamic factor model proposed by P. C. Molenaar (1985) is exhibited, and a dynamic nonstationary factor model (DNFM) is constructed with latent factor series that have time-varying mean functions. The use of a DNFM is illustrated using data from a television viewing habits study. (SLD)

Flexible retrospective selection of temporal resolution in real-time speech MRI using a golden-ratio spiral view order.

PubMed

Kim, Yoon-Chul; Narayanan, Shrikanth S; Nayak, Krishna S

2011-05-01

In speech production research using real-time magnetic resonance imaging (MRI), the analysis of articulatory dynamics is performed retrospectively. A flexible selection of temporal resolution is highly desirable because of natural variations in speech rate and variations in the speed of different articulators. The purpose of the study is to demonstrate a first application of golden-ratio spiral temporal view order to real-time speech MRI and investigate its performance by comparison with conventional bit-reversed temporal view order. Golden-ratio view order proved to be more effective at capturing the dynamics of rapid tongue tip motion. A method for automated blockwise selection of temporal resolution is presented that enables the synthesis of a single video from multiple temporal resolution videos and potentially facilitates subsequent vocal tract shape analysis. Copyright © 2010 Wiley-Liss, Inc.

Flow visualization and characterization of evaporating liquid drops

NASA Technical Reports Server (NTRS)

Chao, David F. (Inventor); Zhang, Nengli (Inventor)

2004-01-01

An optical system, consisting of drop-reflection image, reflection-refracted shadowgraphy and top-view photography, is used to measure the spreading and instant dynamic contact angle of a volatile-liquid drop on a non-transparent substrate. The drop-reflection image and the shadowgraphy is shown by projecting the images of a collimated laser beam partially reflected by the drop and partially passing through the drop onto a screen while the top view photograph is separately viewed by use of a camera video recorder and monitor. For a transparent liquid on a reflective solid surface, thermocapillary convection in the drop, induced by evaporation, can be viewed nonintrusively, and the drop real-time profile data are synchronously recorded by video recording systems. Experimental results obtained from this technique clearly reveal that evaporation and thermocapillary convection greatly affect the spreading process and the characteristics of dynamic contact angle of the drop.

Combination of CT scanning and fluoroscopy imaging on a flat-panel CT scanner

NASA Astrophysics Data System (ADS)

Grasruck, M.; Gupta, R.; Reichardt, B.; Suess, Ch.; Schmidt, B.; Stierstorfer, K.; Popescu, S.; Brady, T.; Flohr, T.

2006-03-01

We developed and evaluated a prototype flat-panel detector based Volume CT (fpVCT) scanner. The fpVCT scanner consists of a Varian 4030CB a-Si flat-panel detector mounted in a multi slice CT-gantry (Siemens Medical Solutions). It provides a 25 cm field of view with 18 cm z-coverage at the isocenter. In addition to the standard tomographic scanning, fpVCT allows two new scan modes: (1) fluoroscopic imaging from any arbitrary rotation angle, and (2) continuous, time-resolved tomographic scanning of a dynamically changing viewing volume. Fluoroscopic imaging is feasible by modifying the standard CT gantry so that the imaging chain can be oriented along any user-selected rotation angle. Scanning with a stationary gantry, after it has been oriented, is equivalent to a conventional fluoroscopic examination. This scan mode enables combined use of high-resolution tomography and real-time fluoroscopy with a clinically usable field of view in the z direction. The second scan mode allows continuous observation of a timeevolving process such as perfusion. The gantry can be continuously rotated for up to 80 sec, with the rotation time ranging from 3 to 20 sec, to gather projection images of a dynamic process. The projection data, that provides a temporal log of the viewing volume, is then converted into multiple image stacks that capture the temporal evolution of a dynamic process. Studies using phantoms, ex vivo specimens, and live animals have confirmed that these new scanning modes are clinically usable and offer a unique view of the anatomy and physiology that heretofore has not been feasible using static CT scanning. At the current level of image quality and temporal resolution, several clinical applications such a dynamic angiography, tumor enhancement pattern and vascularity studies, organ perfusion, and interventional applications are in reach.

Chance of Necessity: Modeling Origins of Life

NASA Technical Reports Server (NTRS)

Pohorille, Andrew

2006-01-01

The fundamental nature of processes that led to the emergence of life has been a subject of long-standing debate. One view holds that the origin of life is an event governed by chance, and the result of so many random events is unpredictable. This view was eloquently expressed by Jacques Monod in his book Chance or Necessity. In an alternative view, the origin of life is considered a deterministic event. Its details need not be deterministic in every respect, but the overall behavior is predictable. A corollary to the deterministic view is that the emergence of life must have been determined primarily by universal chemistry and biochemistry rather than by subtle details of environmental conditions. In my lecture I will explore two different paradigms for the emergence of life and discuss their implications for predictability and universality of life-forming processes. The dominant approach is that the origin of life was guided by information stored in nucleic acids (the RNA World hypothesis). In this view, selection of improved combinations of nucleic acids obtained through random mutations drove evolution of biological systems from their conception. An alternative hypothesis states that the formation of protocellular metabolism was driven by non-genomic processes. Even though these processes were highly stochastic the outcome was largely deterministic, strongly constrained by laws of chemistry. I will argue that self-replication of macromolecules was not required at the early stages of evolution; the reproduction of cellular functions alone was sufficient for self-maintenance of protocells. In fact, the precise transfer of information between successive generations of the earliest protocells was unnecessary and could have impeded the discovery of cellular metabolism. I will also show that such concepts as speciation and fitness to the environment, developed in the context of genomic evolution also hold in the absence of a genome.

On the dynamic activity in sheared corridors of large delta spots

NASA Technical Reports Server (NTRS)

Tang, F.; Wang, H.

1993-01-01

A study of registered, highly time-compressed, white-light movies, made from digital data obtained at Big Bear, revealed dynamic and complex photospheric activity for the first time inside the large delta spot of the March 1989 region. Similar activity in two other regions of large delta spots with sheared penumbral structure was found. They are NOAA Nos. 5629 and 5747 in August and October of 1989, respectively. Both are extraordinarily flare-prolific regions as well. The unusual dynamic activity consists of two parts: the motion of the penumbra and the emergence of new spots in the midst of the penumbral motion. The manner and place of emergence are different from those in ordinary emerging flux regions, and often the spots are without observable opposite polarity flux.

77 FR 26562 - Mobile Offshore Drilling Unit Dynamic Positioning Guidance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

... regarding a draft policy letter on Dynamic Positioning (DP) Systems, Emergency Disconnect Systems, Blowout... Coast Guard, NOSAC issued the report ``Recommendations for Dynamic Positioning System Design and... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2011-1106] Mobile Offshore Drilling Unit Dynamic...

Emergence of dynamic cooperativity in the stochastic kinetics of fluctuating enzymes

NASA Astrophysics Data System (ADS)

Kumar, Ashutosh; Chatterjee, Sambarta; Nandi, Mintu; Dua, Arti

2016-08-01

Dynamic co-operativity in monomeric enzymes is characterized in terms of a non-Michaelis-Menten kinetic behaviour. The latter is believed to be associated with mechanisms that include multiple reaction pathways due to enzymatic conformational fluctuations. Recent advances in single-molecule fluorescence spectroscopy have provided new fundamental insights on the possible mechanisms underlying reactions catalyzed by fluctuating enzymes. Here, we present a bottom-up approach to understand enzyme turnover kinetics at physiologically relevant mesoscopic concentrations informed by mechanisms extracted from single-molecule stochastic trajectories. The stochastic approach, presented here, shows the emergence of dynamic co-operativity in terms of a slowing down of the Michaelis-Menten (MM) kinetics resulting in negative co-operativity. For fewer enzymes, dynamic co-operativity emerges due to the combined effects of enzymatic conformational fluctuations and molecular discreteness. The increase in the number of enzymes, however, suppresses the effect of enzymatic conformational fluctuations such that dynamic co-operativity emerges solely due to the discrete changes in the number of reacting species. These results confirm that the turnover kinetics of fluctuating enzyme based on the parallel-pathway MM mechanism switches over to the single-pathway MM mechanism with the increase in the number of enzymes. For large enzyme numbers, convergence to the exact MM equation occurs in the limit of very high substrate concentration as the stochastic kinetics approaches the deterministic behaviour.

Emergence of dynamic cooperativity in the stochastic kinetics of fluctuating enzymes.

PubMed

Kumar, Ashutosh; Chatterjee, Sambarta; Nandi, Mintu; Dua, Arti

2016-08-28

Dynamic co-operativity in monomeric enzymes is characterized in terms of a non-Michaelis-Menten kinetic behaviour. The latter is believed to be associated with mechanisms that include multiple reaction pathways due to enzymatic conformational fluctuations. Recent advances in single-molecule fluorescence spectroscopy have provided new fundamental insights on the possible mechanisms underlying reactions catalyzed by fluctuating enzymes. Here, we present a bottom-up approach to understand enzyme turnover kinetics at physiologically relevant mesoscopic concentrations informed by mechanisms extracted from single-molecule stochastic trajectories. The stochastic approach, presented here, shows the emergence of dynamic co-operativity in terms of a slowing down of the Michaelis-Menten (MM) kinetics resulting in negative co-operativity. For fewer enzymes, dynamic co-operativity emerges due to the combined effects of enzymatic conformational fluctuations and molecular discreteness. The increase in the number of enzymes, however, suppresses the effect of enzymatic conformational fluctuations such that dynamic co-operativity emerges solely due to the discrete changes in the number of reacting species. These results confirm that the turnover kinetics of fluctuating enzyme based on the parallel-pathway MM mechanism switches over to the single-pathway MM mechanism with the increase in the number of enzymes. For large enzyme numbers, convergence to the exact MM equation occurs in the limit of very high substrate concentration as the stochastic kinetics approaches the deterministic behaviour.

Emergence of dynamic cooperativity in the stochastic kinetics of fluctuating enzymes

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

Kumar, Ashutosh; Chatterjee, Sambarta; Nandi, Mintu

Dynamic co-operativity in monomeric enzymes is characterized in terms of a non-Michaelis-Menten kinetic behaviour. The latter is believed to be associated with mechanisms that include multiple reaction pathways due to enzymatic conformational fluctuations. Recent advances in single-molecule fluorescence spectroscopy have provided new fundamental insights on the possible mechanisms underlying reactions catalyzed by fluctuating enzymes. Here, we present a bottom-up approach to understand enzyme turnover kinetics at physiologically relevant mesoscopic concentrations informed by mechanisms extracted from single-molecule stochastic trajectories. The stochastic approach, presented here, shows the emergence of dynamic co-operativity in terms of a slowing down of the Michaelis-Menten (MM) kineticsmore » resulting in negative co-operativity. For fewer enzymes, dynamic co-operativity emerges due to the combined effects of enzymatic conformational fluctuations and molecular discreteness. The increase in the number of enzymes, however, suppresses the effect of enzymatic conformational fluctuations such that dynamic co-operativity emerges solely due to the discrete changes in the number of reacting species. These results confirm that the turnover kinetics of fluctuating enzyme based on the parallel-pathway MM mechanism switches over to the single-pathway MM mechanism with the increase in the number of enzymes. For large enzyme numbers, convergence to the exact MM equation occurs in the limit of very high substrate concentration as the stochastic kinetics approaches the deterministic behaviour.« less

Challenges and constraints of dynamically emerged source and sink in atomtronic circuits: From closed-system to open-system approaches

PubMed Central

Lai, Chen-Yen; Chien, Chih-Chun

2016-01-01

While batteries offer electronic source and sink for electronic devices, atomic analogues of source and sink and their theoretical descriptions have been a challenge in cold-atom systems. Here we consider dynamically emerged local potentials as controllable source and sink for bosonic atoms. Although a sink potential can collect bosons in equilibrium and indicate its usefulness in the adiabatic limit, sudden switching of the potential exhibits low effectiveness in pushing bosons into it. This is due to conservation of energy and particle in isolated systems such as cold atoms. By varying the potential depth and interaction strength, the systems can further exhibit averse response, where a deeper emerged potential attracts less bosonic atoms into it. To explore possibilities for improving the effectiveness, we investigate what types of system-environment coupling can help bring bosons into a dynamically emerged sink, and a Lindblad operator corresponding to local cooling is found to serve the purpose. PMID:27849034

Hope, despair and hopelessness in living with HIV/AIDS: a grounded theory study.

PubMed

Kylmä, J; Vehviläinen-Julkunen, K; Lähdevirta, J

2001-03-01

Hope, despair or hopelessness have been detected in several research reports as important elements of the lives of persons living with human immunodeficiency virus (HIV) (PLWH) or acquired immunodeficiency syndrome (AIDS) (PLWA). However, there is an obvious gap in the literature suggesting a need to study the overall dynamics of hope (including both hope and despair or hopelessness) along the HIV spectrum from PLWHs' and PLWAs' perspective. The purpose of this study was to describe the dynamics of hope in living with HIV/AIDS. The data were collected through interviewing 10 PLWHs/PLWAs and analysed using a grounded theory method. The dynamics of hope is a multifaceted and complex combination of 'hope', 'despair' and 'hopelessness'. It comprises balancing between 'believing life to be worth living at the present and in the future', 'losing one's grip and sinking into narrowing existence vs. fighting against sinking' and 'giving up in the face of belief in nonexisting future'. A dynamic alternation between hope, despair and hopelessness takes place in the presence of factors that contribute to the 'folding' and 'unfolding' possibilities in everyday life. Factors contributing to the folding possibilities include 'losing', 'fear', 'uncertainty', 'problems in care', 'HIV/AIDS in close ones', 'difficulties in relationships' and 'negative public images and attitudes concerning HIV'. Factors contributing to the unfolding possibilities are 'constructive life experiences', 'wishing not to have HIV while uncertain', 'constructive relationships', 'ability to control one's life', 'finding the meaning of life and zest for life', 'caring', 'noticing one's improved health and the continuance of life', 'increasingly positive attitudes concerning HIV-positive people' and 'protection by law'. The dynamics of hope discovered in this study present new conceptualization, where hope, despair and hopelessness are viewed in relation to each other. The emerged definitions may be used in clinical practice to identify these phenomena in individuals with HIV/AIDS. The discovered factors contributing to the folding and unfolding possibilities can be used in clinical practice to help the individuals along the dynamics of hope.

Dynamic Architecture. New Style Forming Aspects

NASA Astrophysics Data System (ADS)

Belyaeva, T. V.

2017-11-01

The article deals with the methods of buildings and structures transformation in the light of modern solutions in dynamic architecture. The mechanism for the formation of a modern object is proposed. Such design methods are becoming rather relevant in view of today’s trends while the priority of dynamic architecture directions keeps increasing.

How Temporal and Spatial Aspects of Presenting Visualizations Affect Learning about Locomotion Patterns

ERIC Educational Resources Information Center

Imhof, Birgit; Scheiter, Katharina; Edelmann, Jorg; Gerjets, Peter

2012-01-01

Two studies investigated the effectiveness of dynamic and static visualizations for a perceptual learning task (locomotion pattern classification). In Study 1, seventy-five students viewed either dynamic, static-sequential, or static-simultaneous visualizations. For tasks of intermediate difficulty, dynamic visualizations led to better…

Broader perspective on ecosystem sustainability: consequences for decision making.

PubMed

Sidle, Roy C; Benson, William H; Carriger, John F; Kamai, Toshitaka

2013-06-04

Although the concept of ecosystem sustainability has a long-term focus, it is often viewed from a static system perspective. Because most ecosystems are dynamic, we explore sustainability assessments from three additional perspectives: resilient systems; systems where tipping points occur; and systems subject to episodic resetting. Whereas foundations of ecosystem resilience originated in ecology, recent discussions have focused on geophysical attributes, and it is recognized that dynamic system components may not return to their former state following perturbations. Tipping points emerge when chronic changes (typically anthropogenic, but sometimes natural) push ecosystems to thresholds that cause collapse of process and function and may become permanent. Ecosystem resetting occurs when episodic natural disasters breach thresholds with little or no warning, resulting in long-term changes to environmental attributes or ecosystem function. An example of sustainability assessment of ecosystem goods and services along the Gulf Coast (USA) demonstrates the need to include both the resilient and dynamic nature of biogeomorphic components. Mountain road development in northwest Yunnan, China, makes rivers and related habitat vulnerable to tipping points. Ecosystems reset by natural disasters are also presented, emphasizing the need to understand the magnitude frequency and interrelationships among major disturbances, as shown by (i) the 2011 Great East Japan Earthquake and resulting tsunami, including how unsustainable urban development exacerbates geodisaster propagation, and (ii) repeated major earthquakes and associated geomorphic and vegetation disturbances in Papua New Guinea. Although all of these ecosystem perturbations and shifts are individually recognized, they are not embraced in contemporary sustainable decision making.

Phylogenomics and the Dynamic Genome Evolution of the Genus Streptococcus

PubMed Central

Richards, Vincent P.; Palmer, Sara R.; Pavinski Bitar, Paulina D.; Qin, Xiang; Weinstock, George M.; Highlander, Sarah K.; Town, Christopher D.; Burne, Robert A.; Stanhope, Michael J.

2014-01-01

The genus Streptococcus comprises important pathogens that have a severe impact on human health and are responsible for substantial economic losses to agriculture. Here, we utilize 46 Streptococcus genome sequences (44 species), including eight species sequenced here, to provide the first genomic level insight into the evolutionary history and genetic basis underlying the functional diversity of all major groups of this genus. Gene gain/loss analysis revealed a dynamic pattern of genome evolution characterized by an initial period of gene gain followed by a period of loss, as the major groups within the genus diversified. This was followed by a period of genome expansion associated with the origins of the present extant species. The pattern is concordant with an emerging view that genomes evolve through a dynamic process of expansion and streamlining. A large proportion of the pan-genome has experienced lateral gene transfer (LGT) with causative factors, such as relatedness and shared environment, operating over different evolutionary scales. Multiple gene ontology terms were significantly enriched for each group, and mapping terms onto the phylogeny showed that those corresponding to genes born on branches leading to the major groups represented approximately one-fifth of those enriched. Furthermore, despite the extensive LGT, several biochemical characteristics have been retained since group formation, suggesting genomic cohesiveness through time, and that these characteristics may be fundamental to each group. For example, proteolysis: mitis group; urea metabolism: salivarius group; carbohydrate metabolism: pyogenic group; and transcription regulation: bovis group. PMID:24625962

Genuine quark state versus dynamically generated structure for the Roper resonance

NASA Astrophysics Data System (ADS)

Golli, B.; Osmanović, H.; Širca, S.; Švarc, A.

2018-03-01

In view of the recent results of lattice QCD simulation in the P 11 partial wave that has found no clear signal for the three-quark Roper state we investigate a different mechanism for the formation of the Roper resonance in a coupled channel approach including the π N , π Δ , and σ N channels. We fix the pion-baryon vertices in the underlying quark model while the s -wave sigma-baryon interaction is introduced phenomenologically with the coupling strength, the mass, and the width of the σ meson as free parameters. The Laurent-Pietarinen expansion is used to extract the information about the S -matrix pole. The Lippmann-Schwinger equation for the K matrix with a separable kernel is solved to all orders. For sufficiently strong σ N N coupling the kernel becomes singular and a quasibound state emerges at around 1.4 GeV, dominated by the σ N component and reflecting itself in a pole of the S matrix. The alternative mechanism involving a (1s ) 22 s quark resonant state is added to the model and the interplay of the dynamically generated state and the three-quark resonant state is studied. It turns out that for the mass of the three-quark resonant state above 1.6 GeV the mass of the resonance is determined solely by the dynamically generated state, nonetheless, the inclusion of the three-quark resonant state is imperative to reproduce the experimental width and the modulus of the resonance pole.

Combining experimental and simulation data of molecular processes via augmented Markov models.

PubMed

Olsson, Simon; Wu, Hao; Paul, Fabian; Clementi, Cecilia; Noé, Frank

2017-08-01

Accurate mechanistic description of structural changes in biomolecules is an increasingly important topic in structural and chemical biology. Markov models have emerged as a powerful way to approximate the molecular kinetics of large biomolecules while keeping full structural resolution in a divide-and-conquer fashion. However, the accuracy of these models is limited by that of the force fields used to generate the underlying molecular dynamics (MD) simulation data. Whereas the quality of classical MD force fields has improved significantly in recent years, remaining errors in the Boltzmann weights are still on the order of a few [Formula: see text], which may lead to significant discrepancies when comparing to experimentally measured rates or state populations. Here we take the view that simulations using a sufficiently good force-field sample conformations that are valid but have inaccurate weights, yet these weights may be made accurate by incorporating experimental data a posteriori. To do so, we propose augmented Markov models (AMMs), an approach that combines concepts from probability theory and information theory to consistently treat systematic force-field error and statistical errors in simulation and experiment. Our results demonstrate that AMMs can reconcile conflicting results for protein mechanisms obtained by different force fields and correct for a wide range of stationary and dynamical observables even when only equilibrium measurements are incorporated into the estimation process. This approach constitutes a unique avenue to combine experiment and computation into integrative models of biomolecular structure and dynamics.

Broader perspective on ecosystem sustainability: Consequences for decision making

PubMed Central

Sidle, Roy C.; Benson, William H.; Carriger, John F.; Kamai, Toshitaka

2013-01-01

Although the concept of ecosystem sustainability has a long-term focus, it is often viewed from a static system perspective. Because most ecosystems are dynamic, we explore sustainability assessments from three additional perspectives: resilient systems; systems where tipping points occur; and systems subject to episodic resetting. Whereas foundations of ecosystem resilience originated in ecology, recent discussions have focused on geophysical attributes, and it is recognized that dynamic system components may not return to their former state following perturbations. Tipping points emerge when chronic changes (typically anthropogenic, but sometimes natural) push ecosystems to thresholds that cause collapse of process and function and may become permanent. Ecosystem resetting occurs when episodic natural disasters breach thresholds with little or no warning, resulting in long-term changes to environmental attributes or ecosystem function. An example of sustainability assessment of ecosystem goods and services along the Gulf Coast (USA) demonstrates the need to include both the resilient and dynamic nature of biogeomorphic components. Mountain road development in northwest Yunnan, China, makes rivers and related habitat vulnerable to tipping points. Ecosystems reset by natural disasters are also presented, emphasizing the need to understand the magnitude frequency and interrelationships among major disturbances, as shown by (i) the 2011 Great East Japan Earthquake and resulting tsunami, including how unsustainable urban development exacerbates geodisaster propagation, and (ii) repeated major earthquakes and associated geomorphic and vegetation disturbances in Papua New Guinea. Although all of these ecosystem perturbations and shifts are individually recognized, they are not embraced in contemporary sustainable decision making. PMID:23686583

Ultrahigh-definition dynamic 3D holographic display by active control of volume speckle fields

NASA Astrophysics Data System (ADS)

Yu, Hyeonseung; Lee, Kyeoreh; Park, Jongchan; Park, Yongkeun

2017-01-01

Holographic displays generate realistic 3D images that can be viewed without the need for any visual aids. They operate by generating carefully tailored light fields that replicate how humans see an actual environment. However, the realization of high-performance, dynamic 3D holographic displays has been hindered by the capabilities of present wavefront modulator technology. In particular, spatial light modulators have a small diffraction angle range and limited pixel number limiting the viewing angle and image size of a holographic 3D display. Here, we present an alternative method to generate dynamic 3D images by controlling volume speckle fields significantly enhancing image definition. We use this approach to demonstrate a dynamic display of micrometre-sized optical foci in a volume of 8 mm × 8 mm × 20 mm.

View of parking (resting) frame that supported the Shuttle assembly ...

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

View of parking (resting) frame that supported the Shuttle assembly when the hydrodynamic supports were not engaged (removed from structure). - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

Viewing region maximization of an integral floating display through location adjustment of viewing window.

PubMed

Kim, Joowhan; Min, Sung-Wook; Lee, Byoungho

2007-10-01

Integral floating display is a recently proposed three-dimensional (3D) display method which provides a dynamic 3D image in the vicinity to an observer. It has a viewing window only through which correct 3D images can be observed. However, the positional difference between the viewing window and the floating image causes limited viewing zone in integral floating system. In this paper, we provide the principle and experimental results of the location adjustment of the viewing window of the integral floating display system by modifying the elemental image region for integral imaging. We explain the characteristics of the viewing window and propose how to move the viewing window to maximize the viewing zone.

Biological Agency: Its Subjective Foundations and a Large-Scale Taxonomy

PubMed Central

Brizio, Adelina; Tirassa, Maurizio

2016-01-01

We will outline a theory of agency cast in theoretical psychology, viewed as a branch of a non-eliminativist biology. Our proposal will be based on an evolutionary view of the nature and functioning of the mind(s), reconsidered in a radically subjectivist, radically constructivist framework. We will argue that the activities of control systems should be studied in terms of interaction. Specifically, what an agent does belongs to the coupling of its internal dynamics with the dynamics of the external world. The internal dynamics, rooted in the species' phylogenetic history as well as in the individual's ontogenetic path, (a) determine which external dynamics are relevant to the organism, that is, they create the subjective ontology that the organism senses in the external world, and (b) determine what types of activities and actions the agent is able to conceive of and to adopt in the current situation. The external dynamics that the organism senses thus constitute its subjective environment. This notion of coupling is basically suitable for whichever organism one may want to consider. However, remarkable differences exist between the ways in which coupling may be realized, that is, between different natures and ways of functioning of control systems. We will describe agency at different phylogenetic levels: at the very least, it is necessary to discriminate between non-Intentional species, Intentional species, and a subtype of the latter called meta-Intentional. We will claim that agency can only be understood in a radically subjectivist perspective, which in turn is best grounded in a view of the mind as consciousness and experience. We will thus advance a radically constructivist view of agency and of several correlate notions (like meaning and ontology). PMID:26903891

Biological Agency: Its Subjective Foundations and a Large-Scale Taxonomy.

PubMed

Brizio, Adelina; Tirassa, Maurizio

2016-01-01

We will outline a theory of agency cast in theoretical psychology, viewed as a branch of a non-eliminativist biology. Our proposal will be based on an evolutionary view of the nature and functioning of the mind(s), reconsidered in a radically subjectivist, radically constructivist framework. We will argue that the activities of control systems should be studied in terms of interaction. Specifically, what an agent does belongs to the coupling of its internal dynamics with the dynamics of the external world. The internal dynamics, rooted in the species' phylogenetic history as well as in the individual's ontogenetic path, (a) determine which external dynamics are relevant to the organism, that is, they create the subjective ontology that the organism senses in the external world, and (b) determine what types of activities and actions the agent is able to conceive of and to adopt in the current situation. The external dynamics that the organism senses thus constitute its subjective environment. This notion of coupling is basically suitable for whichever organism one may want to consider. However, remarkable differences exist between the ways in which coupling may be realized, that is, between different natures and ways of functioning of control systems. We will describe agency at different phylogenetic levels: at the very least, it is necessary to discriminate between non-Intentional species, Intentional species, and a subtype of the latter called meta-Intentional. We will claim that agency can only be understood in a radically subjectivist perspective, which in turn is best grounded in a view of the mind as consciousness and experience. We will thus advance a radically constructivist view of agency and of several correlate notions (like meaning and ontology).

Resting-State Functional Connectivity Emerges from Structurally and Dynamically Shaped Slow Linear Fluctuations

PubMed Central

Deco, Gustavo; Mantini, Dante; Romani, Gian Luca; Hagmann, Patric; Corbetta, Maurizio

2013-01-01

Brain fluctuations at rest are not random but are structured in spatial patterns of correlated activity across different brain areas. The question of how resting-state functional connectivity (FC) emerges from the brain's anatomical connections has motivated several experimental and computational studies to understand structure–function relationships. However, the mechanistic origin of resting state is obscured by large-scale models' complexity, and a close structure–function relation is still an open problem. Thus, a realistic but simple enough description of relevant brain dynamics is needed. Here, we derived a dynamic mean field model that consistently summarizes the realistic dynamics of a detailed spiking and conductance-based synaptic large-scale network, in which connectivity is constrained by diffusion imaging data from human subjects. The dynamic mean field approximates the ensemble dynamics, whose temporal evolution is dominated by the longest time scale of the system. With this reduction, we demonstrated that FC emerges as structured linear fluctuations around a stable low firing activity state close to destabilization. Moreover, the model can be further and crucially simplified into a set of motion equations for statistical moments, providing a direct analytical link between anatomical structure, neural network dynamics, and FC. Our study suggests that FC arises from noise propagation and dynamical slowing down of fluctuations in an anatomically constrained dynamical system. Altogether, the reduction from spiking models to statistical moments presented here provides a new framework to explicitly understand the building up of FC through neuronal dynamics underpinned by anatomical connections and to drive hypotheses in task-evoked studies and for clinical applications. PMID:23825427

Resting-state functional connectivity emerges from structurally and dynamically shaped slow linear fluctuations.

PubMed

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

2013-07-03

Brain fluctuations at rest are not random but are structured in spatial patterns of correlated activity across different brain areas. The question of how resting-state functional connectivity (FC) emerges from the brain's anatomical connections has motivated several experimental and computational studies to understand structure-function relationships. However, the mechanistic origin of resting state is obscured by large-scale models' complexity, and a close structure-function relation is still an open problem. Thus, a realistic but simple enough description of relevant brain dynamics is needed. Here, we derived a dynamic mean field model that consistently summarizes the realistic dynamics of a detailed spiking and conductance-based synaptic large-scale network, in which connectivity is constrained by diffusion imaging data from human subjects. The dynamic mean field approximates the ensemble dynamics, whose temporal evolution is dominated by the longest time scale of the system. With this reduction, we demonstrated that FC emerges as structured linear fluctuations around a stable low firing activity state close to destabilization. Moreover, the model can be further and crucially simplified into a set of motion equations for statistical moments, providing a direct analytical link between anatomical structure, neural network dynamics, and FC. Our study suggests that FC arises from noise propagation and dynamical slowing down of fluctuations in an anatomically constrained dynamical system. Altogether, the reduction from spiking models to statistical moments presented here provides a new framework to explicitly understand the building up of FC through neuronal dynamics underpinned by anatomical connections and to drive hypotheses in task-evoked studies and for clinical applications.

System-level view of geospace dynamics: Challenges for high-latitude ground-based observations

NASA Astrophysics Data System (ADS)

Donovan, E.

2014-12-01

Increasingly, research programs including GEM, CEDAR, GEMSIS, GO Canada, and others are focusing on how geospace works as a system. Coupling sits at the heart of system level dynamics. In all cases, coupling is accomplished via fundamental processes such as reconnection and plasma waves, and can be between regions, energy ranges, species, scales, and energy reservoirs. Three views of geospace are required to attack system level questions. First, we must observe the fundamental processes that accomplish the coupling. This "observatory view" requires in situ measurements by satellite-borne instruments or remote sensing from powerful well-instrumented ground-based observatories organized around, for example, Incoherent Scatter Radars. Second, we need to see how this coupling is controlled and what it accomplishes. This demands quantitative observations of the system elements that are being coupled. This "multi-scale view" is accomplished by networks of ground-based instruments, and by global imaging from space. Third, if we take geospace as a whole, the system is too complicated, so at the top level we need time series of simple quantities such as indices that capture important aspects of the system level dynamics. This requires a "key parameter view" that is typically provided through indices such as AE and DsT. With the launch of MMS, and ongoing missions such as THEMIS, Cluster, Swarm, RBSP, and ePOP, we are entering a-once-in-a-lifetime epoch with a remarkable fleet of satellites probing processes at key regions throughout geospace, so the observatory view is secure. With a few exceptions, our key parameter view provides what we need. The multi-scale view, however, is compromised by space/time scales that are important but under-sampled, combined extent of coverage and resolution that falls short of what we need, and inadequate conjugate observations. In this talk, I present an overview of what we need for taking system level research to its next level, and how high latitude ground based observations can address these challenges.

Transformation of Cortex-wide Emergent Properties during Motor Learning.

PubMed

Makino, Hiroshi; Ren, Chi; Liu, Haixin; Kim, An Na; Kondapaneni, Neehar; Liu, Xin; Kuzum, Duygu; Komiyama, Takaki

2017-05-17

Learning involves a transformation of brain-wide operation dynamics. However, our understanding of learning-related changes in macroscopic dynamics is limited. Here, we monitored cortex-wide activity of the mouse brain using wide-field calcium imaging while the mouse learned a motor task over weeks. Over learning, the sequential activity across cortical modules became temporally more compressed, and its trial-by-trial variability decreased. Moreover, a new flow of activity emerged during learning, originating from premotor cortex (M2), and M2 became predictive of the activity of many other modules. Inactivation experiments showed that M2 is critical for the post-learning dynamics in the cortex-wide activity. Furthermore, two-photon calcium imaging revealed that M2 ensemble activity also showed earlier activity onset and reduced variability with learning, which was accompanied by changes in the activity-movement relationship. These results reveal newly emergent properties of macroscopic cortical dynamics during motor learning and highlight the importance of M2 in controlling learned movements. Copyright © 2017 Elsevier Inc. All rights reserved.

Sweeping Arches and Loops [video

NASA Image and Video Library

2014-07-10

Two active regions with their intense magnetic fields produced towering arches and spiraling coils of solar loops above them (June 29 - July 1, 2014) as they rotated into view. When viewed in extreme ultraviolet light, magnetic field lines are revealed by charged particles that travel along them. These active regions appear as dark sunspots when viewed in filtered light. Note the small blast in the upper of the two major active regions, followed by more coils of loops as the region reorganizes itself. The still was taken on June 30 at 10:33 UT. Credit: NASA/Solar Dynamics Observatory Two active regions with their intense magnetic fields produced towering arches and spiraling coils of solar loops above them (June 29 - July 1, 2014) as they rotated into view. When viewed in extreme ultraviolet light, magnetic field lines are revealed by charged particles that travel along them. These active regions appear as dark sunspots when viewed in filtered light. Note the small blast in the upper of the two major active regions, followed by more coils of loops as the region reorganizes itself. The still was taken on June 30 at 10:33 UT. Credit: Solar Dynamics Observatory/NASA.

Caustic Skeleton & Cosmic Web

NASA Astrophysics Data System (ADS)

Feldbrugge, Job; van de Weygaert, Rien; Hidding, Johan; Feldbrugge, Joost

2018-05-01

We present a general formalism for identifying the caustic structure of a dynamically evolving mass distribution, in an arbitrary dimensional space. The identification of caustics in fluids with Hamiltonian dynamics, viewed in Lagrangian space, corresponds to the classification of singularities in Lagrangian catastrophe theory. On the basis of this formalism we develop a theoretical framework for the dynamics of the formation of the cosmic web, and specifically those aspects that characterize its unique nature: its complex topological connectivity and multiscale spinal structure of sheetlike membranes, elongated filaments and compact cluster nodes. Given the collisionless nature of the gravitationally dominant dark matter component in the universe, the presented formalism entails an accurate description of the spatial organization of matter resulting from the gravitationally driven formation of cosmic structure. The present work represents a significant extension of the work by Arnol'd et al. [1], who classified the caustics that develop in one- and two-dimensional systems that evolve according to the Zel'dovich approximation. His seminal work established the defining role of emerging singularities in the formation of nonlinear structures in the universe. At the transition from the linear to nonlinear structure evolution, the first complex features emerge at locations where different fluid elements cross to establish multistream regions. Involving a complex folding of the 6-D sheetlike phase-space distribution, it manifests itself in the appearance of infinite density caustic features. The classification and characterization of these mass element foldings can be encapsulated in caustic conditions on the eigenvalue and eigenvector fields of the deformation tensor field. In this study we introduce an alternative and transparent proof for Lagrangian catastrophe theory. This facilitates the derivation of the caustic conditions for general Lagrangian fluids, with arbitrary dynamics. Most important in the present context is that it allows us to follow and describe the full three-dimensional geometric and topological complexity of the purely gravitationally evolving nonlinear cosmic matter field. While generic and statistical results can be based on the eigenvalue characteristics, one of our key findings is that of the significance of the eigenvector field of the deformation field for outlining the entire spatial structure of the caustic skeleton emerging from a primordial density field. In this paper we explicitly consider the caustic conditions for the three-dimensional Zel'dovich approximation, extending earlier work on those for one- and two-dimensional fluids towards the full spatial richness of the cosmic web. In an accompanying publication, we apply this towards a full three-dimensional study of caustics in the formation of the cosmic web and evaluate in how far it manages to outline and identify the intricate skeletal features in the corresponding N-body simulations.

78 FR 23557 - Fipronil; Receipt of Application for Emergency Exemptions, Solicitation of Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

... your concerns and suggest alternatives. vii. Explain your views as clearly as possible, avoiding the... population who, as a result of their location, cultural practices, or other factors, may have atypical or... that an emergency situation exists based upon three factors: A severe increase in cabbage maggot...

Teaching Business Strategy for an Emerging Economy: An Internet-Based Simulation.

ERIC Educational Resources Information Center

Miller, Van V.

2003-01-01

Describes an Internet-based simulation used in a course about business strategy in an emerging economy. The simulation, when coupled with today's dominant strategy paradigm, the Resource Based View, appears to yield a course design that attracts students while emphasizing the actual substance which is crucial in such a course. (EV)

The Potential of Threshold Concepts: An Emerging Framework for Educational Research and Practice

ERIC Educational Resources Information Center

Lucas, Ursula; Mladenovic, Rosina

2007-01-01

This paper explores the notion of a "threshold concept" and discusses its possible implications for higher education research and practice. Using the case of introductory accounting as an illustration, it is argued that the idea of a threshold concept provides an emerging theoretical framework for a "re-view" of educational…

Collaborative practices in unscheduled emergency care: role and impact of the emergency care practitioner—qualitative and summative findings

PubMed Central

Cooper, Simon; O'Carroll, Judith; Jenkin, Annie; Badger, Beryl

2007-01-01

Objective To identify collaborative instances and hindrances and to produce a model of collaborative practice. Methods A 12‐month (2005–2006) mixed methods clinical case study was carried out in a large UK ambulance trust. Collaboration was measured through direct observational ratings of communication skills, teamwork and leadership with 24 multi‐professional emergency care practitioners (ECPs), interviews with 45 ECPs and stakeholders, and an audit of 611 patients Results Using a generic qualitative approach, observational records and interviews showed that ECPs' numerous links with other professions were influenced by three major themes as follows. (i) The ECP role: for example, “restricted transport codes” of communication, focus on reducing admissions, frustrations about patient tasking and conflicting views about leadership and team work. (ii) Education and training: drivers for multi‐professional clinically focussed graduate level education, requirements for skill development in minor injury units (MIUs) and general practice, and the need for clinical supervision/mentorship. (iii) Cultural perspectives: a “crew room” blue collar view of inter‐professional working versus emerging professional white collar views, power and communication conflicts, and a lack of understanding of the ECPs' role. The quantitative findings are reported elsewhere. Conclusions The final model of collaborative practice suggests that ECPs are having an impact on patient care, but that improvements can be made. We recommend the appointment of ECP clinical leads, degree level clinically focussed multi‐professional education, communication skills training, clinical supervision and multi‐professional ECP appointments. PMID:17711937

What happened when Scottish women were given advance supplies of emergency contraception? A survey and qualitative study of women's views and experiences.

PubMed

Ziebland, Sue; Wyke, Sally; Seaman, Pete; Fairhurst, Karen; Walker, Jeremy; Glasier, Anna

2005-04-01

The Lothian Emergency Contraception Project in Scotland was a radical intervention in which women aged 16-29 were given 5 packs of emergency contraception (EC) to keep at home. We use survey and qualitative interview data to describe how women used the project packs and their views of advance supplies. The women's accounts suggest that concerns that eased access to emergency contraception will lead to repeated use and risky sex appear to be largely unfounded. Women were pleased to be offered the packs, which were reported as having practical advantages and also sparing them the difficulty of negotiating a sometimes awkward consultation. Respondents explained how they used their packs of EC and in their accounts used justifications, repetition and distancing to emphasise that they would not take risks with contraception or sexually transmitted infections. We interpret the data in the light of the observation that EC has an anomalous role in contraception and the work of applied linguists Candlin and Lucas who have demonstrated the difficulties inherent in the family planning consultation.

Disease elimination and re-emergence in differential-equation models.

PubMed

Greenhalgh, Scott; Galvani, Alison P; Medlock, Jan

2015-12-21

Traditional differential equation models of disease transmission are often used to predict disease trajectories and evaluate the effectiveness of alternative intervention strategies. However, such models cannot account explicitly for probabilistic events, such as those that dominate dynamics when disease prevalence is low during the elimination and re-emergence phases of an outbreak. To account for the dynamics at low prevalence, i.e. the elimination and risk of disease re-emergence, without the added analytical and computational complexity of a stochastic model, we develop a novel application of control theory. We apply our approach to analyze historical data of measles elimination and re-emergence in Iceland from 1923 to 1938, predicting the temporal trajectory of local measles elimination and re-emerge as a result of disease migration from Copenhagen, Denmark. Copyright © 2015 Elsevier Ltd. All rights reserved.

Credit WCT. Photographic copy of photograph, view east southeast across ...

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

Credit WCT. Photographic copy of photograph, view east southeast across Dd station ejectors showing detail of "Hyprox" steam generator. Note that steam generator is placed above Z-stage ejector; an insulated pipe running between the Dd train rails supplies steam to the Y-Stage ejector. Note emergency eyewash stand at extreme right of view. (JPL negative no. 384-3376, 3 December 1962) - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

Vapor-Generator Wand Helps To Reveal Airflow Patterns

NASA Technical Reports Server (NTRS)

Robelen, David B.

1993-01-01

In vapor-generator wand, liquid propylene glycol flows into electrically heated stainless-steel tube. Liquid boils in heated tube, and emerging vapor forms dense, smoke-like fog used to make airflow patterns visible. Built in variety of sizes, suitable for uses ranging from tabletop demonstrations to research in wind tunnels. For best viewing, plume illuminated by bright, focused incandescent spotlight at right angle to viewing direction. Viewing further enhanced by coating walls of test chamber with flat, dark color to minimize reflections and increase contrast.

The Role of Romantic Partners, Family, and Peer Networks in Dating Couples' Views about Cohabitation

ERIC Educational Resources Information Center

Manning, Wendy D.; Cohen, Jessica A.; Smock, Pamela J.

2011-01-01

Emerging adults are increasingly cohabiting, but few studies have considered the role of social context in the formation of their views of cohabitation. Drawing on 40 semistructured interviews with dating couples, we explored the role of romantic partners, family, and peers on evaluations of cohabitation. In couples where each member had a…