High-Level Ab Initio Calculations of Intermolecular Interactions: Heavy Main-Group Element π-Interactions.

PubMed

Krasowska, Małgorzata; Schneider, Wolfgang B; Mehring, Michael; Auer, Alexander A

2018-05-02

This work reports high-level ab initio calculations and a detailed analysis on the nature of intermolecular interactions of heavy main-group element compounds and π systems. For this purpose we have chosen a set of benchmark molecules of the form MR 3 , in which M=As, Sb, or Bi, and R=CH 3 , OCH 3 , or Cl. Several methods for the description of weak intermolecular interactions are benchmarked including DFT-D, DFT-SAPT, MP2, and high-level coupled cluster methods in the DLPNO-CCSD(T) approximation. Using local energy decomposition (LED) and an analysis of the electron density, details of the nature of this interaction are unraveled. The results yield insight into the nature of dispersion and donor-acceptor interactions in this type of system, including systematic trends in the periodic table, and also provide a benchmark for dispersion interactions in heavy main-group element compounds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Efficient Method to Evaluate Intermolecular Interaction Energies in Large Systems Using Overlapping Multicenter ONIOM and the Fragment Molecular Orbital Method

PubMed Central

Asada, Naoya; Fedorov, Dmitri G.; Kitaura, Kazuo; Nakanishi, Isao; Merz, Kenneth M.

2012-01-01

We propose an approach based on the overlapping multicenter ONIOM to evaluate intermolecular interaction energies in large systems and demonstrate its accuracy on several representative systems in the complete basis set limit at the MP2 and CCSD(T) level of theory. In the application to the intermolecular interaction energy between insulin dimer and 4′-hydroxyacetanilide at the MP2/CBS level, we use the fragment molecular orbital method for the calculation of the entire complex assigned to the lowest layer in three-layer ONIOM. The developed method is shown to be efficient and accurate in the evaluation of the protein-ligand interaction energies. PMID:23050059

Placing Students at the Heart of the Iron Triangle and the Interaction Equivalence Theorem Models

ERIC Educational Resources Information Center

Lane, Andy

2014-01-01

A number of visual models have been proposed to help explain the interplay and interactions between specified components of higher education systems at different levels and to take account of emerging trends towards open education systems. At sector and institutional levels the notion of an iron triangle has been posited, linking firstly access,…

The Bilingual Language Interaction Network for Comprehension of Speech

ERIC Educational Resources Information Center

Shook, Anthony; Marian, Viorica

2013-01-01

During speech comprehension, bilinguals co-activate both of their languages, resulting in cross-linguistic interaction at various levels of processing. This interaction has important consequences for both the structure of the language system and the mechanisms by which the system processes spoken language. Using computational modeling, we can…

Psyche and soma: New insights into the connection.

PubMed

Kumar, Rahul; Yeragani, Vikram K

2010-01-01

The interaction of Psyche and Soma are well known and this interaction happens through a complex network of feedback, medication, and modulation among the central and autonomic nervous systems, the endocrine system, the immune system, and the stress system. These systems, which were previously considered pristinely independent, in fact, interact at myriad levels. Psychoneuroimmunology (PNI) is an emerging discipline that focuses on various interactions among these body systems and provides the underpinnings of a scientific explanation for what is commonly referred to as the mind-body connection. This article reviews the relevant literature with an emphasis on Indian research.

Psyche and soma: New insights into the connection

PubMed Central

Kumar, Rahul; Yeragani, Vikram K.

2010-01-01

The interaction of Psyche and Soma are well known and this interaction happens through a complex network of feedback, medication, and modulation among the central and autonomic nervous systems, the endocrine system, the immune system, and the stress system. These systems, which were previously considered pristinely independent, in fact, interact at myriad levels. Psychoneuroimmunology (PNI) is an emerging discipline that focuses on various interactions among these body systems and provides the underpinnings of a scientific explanation for what is commonly referred to as the mind-body connection. This article reviews the relevant literature with an emphasis on Indian research. PMID:21836684

Web-Based Interactive System for Analyzing Achievement Gaps in Public Schools System

ERIC Educational Resources Information Center

Wang, Kening; Mulvenon, Sean W.; Stegman, Charles; Xia, Yanling

2010-01-01

The National Office for Research on Measurement and Evaluation Systems (NORMES) at the University of Arkansas developed a web-based interactive system to provide information on state, district, and school level achievement gaps between white students and black students, socioeconomically disadvantaged students and non-disadvantaged students, male…

Human factors evaluation of level 2 and level 3 automated driving concepts : concepts of operation.

DOT National Transportation Integrated Search

2014-07-01

The Concepts of Operation document evaluates the functional framework of operations for Level 2 and Level 3 automated vehicle systems. This is done by defining the varying levels of automation, the operator vehicle interactions, and system components...

Multiscale modeling of the dynamics of multicellular systems

NASA Astrophysics Data System (ADS)

Kosztin, Ioan

2011-03-01

Describing the biomechanical properties of cellular systems, regarded as complex highly viscoelastic materials, is a difficult problem of great conceptual and practical value. Here we present a novel approach, referred to as the Cellular Particle Dynamics (CPD) method, for: (i) quantitatively relating biomechanical properties at the cell level to those at the multicellular and tissue level, and (ii) describing and predicting the time evolution of multicellular systems that undergo biomechanical relaxations. In CPD cells are modeled as an ensemble of cellular particles (CPs) that interact via short range contact interactions, characterized by an attractive (adhesive interaction) and a repulsive (excluded volume interaction) component. The time evolution of the spatial conformation of the multicellular system is determined by following the trajectories of all CPs through integration of their equations of motion. Cell and multicellular level biomechanical properties (e.g., viscosity, surface tension and shear modulus) are determined through the combined use of experiments and theory of continuum viscoelastic media. The same biomechanical properties are also ``measured'' computationally by employing the CPD method, the results being expressed in terms of CPD parameters. Once these parameters have been calibrated experimentally, the formalism provides a systematic framework to predict the time evolution of complex multicellular systems during shape-changing biomechanical transformations. By design, the CPD method is rather flexible and most suitable for multiscale modeling of multicellular system. The spatial level of detail of the system can be easily tuned by changing the number of CPs in a cell. Thus, CPD can be used equally well to describe both cell level processes (e.g., the adhesion of two cells) and tissue level processes (e.g., the formation of 3D constructs of millions of cells through bioprinting). Work supported by NSF [FIBR-0526854 and PHY-0957914]. Computer time provided by the University of Missouri Bioinformatics Consortium.

Observation of nonlinear optical interactions of ultralow levels of light in a tapered optical nanofiber embedded in a hot rubidium vapor.

PubMed

Spillane, S M; Pati, G S; Salit, K; Hall, M; Kumar, P; Beausoleil, R G; Shahriar, M S

2008-06-13

We report the observation of low-light level optical interactions in a tapered optical nanofiber (TNF) embedded in a hot rubidium vapor. The small optical mode area plays a significant role in the optical properties of the hot vapor Rb-TNF system, allowing nonlinear optical interactions with nW level powers even in the presence of transit-time dephasing rates much larger than the intrinsic linewidth. We demonstrate nonlinear absorption and V-type electromagnetically induced transparency with cw powers below 10 nW, comparable to the best results in any Rb-optical waveguide system. The good performance and flexibility of the Rb-TNF system makes it a very promising candidate for ultralow power resonant nonlinear optical applications.

Formulation of advanced consumables management models: Environmental control and electrical power system performance models requirements

NASA Technical Reports Server (NTRS)

Daly, J. K.; Torian, J. G.

1979-01-01

Software design specifications for developing environmental control and life support system (ECLSS) and electrical power system (EPS) programs into interactive computer programs are presented. Specifications for the ECLSS program are at the detail design level with respect to modification of an existing batch mode program. The FORTRAN environmental analysis routines (FEAR) are the subject batch mode program. The characteristics of the FEAR program are included for use in modifying batch mode programs to form interactive programs. The EPS program specifications are at the preliminary design level. Emphasis is on top-down structuring in the development of an interactive program.

Tunability of the fractional quantum Hall states in buckled Dirac materials

NASA Astrophysics Data System (ADS)

Apalkov, Vadym M.; Chakraborty, Tapash

2014-12-01

We report on the fractional quantum Hall states of germanene and silicene where one expects a strong spin-orbit interaction. This interaction causes an enhancement of the electron-electron interaction strength in one of the Landau levels corresponding to the valence band of the system. This enhancement manifests itself as an increase of the fractional quantum Hall effect gaps compared to that in graphene and is due to the spin-orbit induced coupling of the Landau levels of the conduction and valence bands, which modifies the corresponding wave functions and the interaction within a single level. Due to the buckled structure, a perpendicular electric field lifts the valley degeneracy and strongly modifies the interaction effects within a single Landau level: in one valley the perpendicular electric field enhances the interaction strength in the conduction band Landau level, while in another valley, the electric field strongly suppresses the interaction effects.

Social interaction in synthetic and natural microbial communities.

PubMed

Xavier, Joao B

2011-04-12

Social interaction among cells is essential for multicellular complexity. But how do molecular networks within individual cells confer the ability to interact? And how do those same networks evolve from the evolutionary conflict between individual- and population-level interests? Recent studies have dissected social interaction at the molecular level by analyzing both synthetic and natural microbial populations. These studies shed new light on the role of population structure for the evolution of cooperative interactions and revealed novel molecular mechanisms that stabilize cooperation among cells. New understanding of populations is changing our view of microbial processes, such as pathogenesis and antibiotic resistance, and suggests new ways to fight infection by exploiting social interaction. The study of social interaction is also challenging established paradigms in cancer evolution and immune system dynamics. Finding similar patterns in such diverse systems suggests that the same 'social interaction motifs' may be general to many cell populations.

Hydrographs showing groundwater levels for selected wells in the Puyallup River watershed and vicinity, Pierce and King Counties, Washington

USGS Publications Warehouse

Lane, R.C.; Julich, R.J.; Justin, G.B.

2013-01-01

Hydrographs of groundwater levels for selected wells in and adjacent to the Puyallup River watershed in Pierce and King Counties, Washington, are presented using an interactive Web-based map of the study area to illustrate changes in groundwater levels on a monthly and seasonal basis. The interactive map displays well locations that link to the hydrographs, which in turn link to the U.S. Geological Survey National Water Information System, Groundwater Site Inventory System.

Trophic interaction modifications: an empirical and theoretical framework.

PubMed

Terry, J Christopher D; Morris, Rebecca J; Bonsall, Michael B

2017-10-01

Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Gray-level transformations for interactive image enhancement. M.S. Thesis. Final Technical Report

NASA Technical Reports Server (NTRS)

Fittes, B. A.

1975-01-01

A gray-level transformation method suitable for interactive image enhancement was presented. It is shown that the well-known histogram equalization approach is a special case of this method. A technique for improving the uniformity of a histogram is also developed. Experimental results which illustrate the capabilities of both algorithms are described. Two proposals for implementing gray-level transformations in a real-time interactive image enhancement system are also presented.

The Social Interactive Coding System (SICS): An On-Line, Clinically Relevant Descriptive Tool.

ERIC Educational Resources Information Center

Rice, Mabel L.; And Others

1990-01-01

The Social Interactive Coding System (SICS) assesses the continuous verbal interactions of preschool children as a function of play areas, addressees, script codes, and play levels. This paper describes the 26 subjects and the setting involved in SICS development, coding definitions and procedures, training procedures, reliability, sample…

Overview of the interactive task in BioCreative V

PubMed Central

Wang, Qinghua; S. Abdul, Shabbir; Almeida, Lara; Ananiadou, Sophia; Balderas-Martínez, Yalbi I.; Batista-Navarro, Riza; Campos, David; Chilton, Lucy; Chou, Hui-Jou; Contreras, Gabriela; Cooper, Laurel; Dai, Hong-Jie; Ferrell, Barbra; Fluck, Juliane; Gama-Castro, Socorro; George, Nancy; Gkoutos, Georgios; Irin, Afroza K.; Jensen, Lars J.; Jimenez, Silvia; Jue, Toni R.; Keseler, Ingrid; Madan, Sumit; Matos, Sérgio; McQuilton, Peter; Milacic, Marija; Mort, Matthew; Natarajan, Jeyakumar; Pafilis, Evangelos; Pereira, Emiliano; Rao, Shruti; Rinaldi, Fabio; Rothfels, Karen; Salgado, David; Silva, Raquel M.; Singh, Onkar; Stefancsik, Raymund; Su, Chu-Hsien; Subramani, Suresh; Tadepally, Hamsa D.; Tsaprouni, Loukia; Vasilevsky, Nicole; Wang, Xiaodong; Chatr-Aryamontri, Andrew; Laulederkind, Stanley J. F.; Matis-Mitchell, Sherri; McEntyre, Johanna; Orchard, Sandra; Pundir, Sangya; Rodriguez-Esteban, Raul; Van Auken, Kimberly; Lu, Zhiyong; Schaeffer, Mary; Wu, Cathy H.; Hirschman, Lynette; Arighi, Cecilia N.

2016-01-01

Fully automated text mining (TM) systems promote efficient literature searching, retrieval, and review but are not sufficient to produce ready-to-consume curated documents. These systems are not meant to replace biocurators, but instead to assist them in one or more literature curation steps. To do so, the user interface is an important aspect that needs to be considered for tool adoption. The BioCreative Interactive task (IAT) is a track designed for exploring user-system interactions, promoting development of useful TM tools, and providing a communication channel between the biocuration and the TM communities. In BioCreative V, the IAT track followed a format similar to previous interactive tracks, where the utility and usability of TM tools, as well as the generation of use cases, have been the focal points. The proposed curation tasks are user-centric and formally evaluated by biocurators. In BioCreative V IAT, seven TM systems and 43 biocurators participated. Two levels of user participation were offered to broaden curator involvement and obtain more feedback on usability aspects. The full level participation involved training on the system, curation of a set of documents with and without TM assistance, tracking of time-on-task, and completion of a user survey. The partial level participation was designed to focus on usability aspects of the interface and not the performance per se. In this case, biocurators navigated the system by performing pre-designed tasks and then were asked whether they were able to achieve the task and the level of difficulty in completing the task. In this manuscript, we describe the development of the interactive task, from planning to execution and discuss major findings for the systems tested. Database URL: http://www.biocreative.org PMID:27589961

Overview of the interactive task in BioCreative V

DOE PAGES

Wang, Qinghua; Abdul, Shabbir S.; Almeida, Lara; ...

2016-09-01

Fully automated text mining (TM) systems promote efficient literature searching, retrieval, and review but are not sufficient to produce ready-to-consume curated documents. These systems are not meant to replace biocurators, but instead to assist them in one or more literature curation steps. To do so, the user interface is an important aspect that needs to be considered for tool adoption. The BioCreative Interactive task (IAT) is a track designed for exploring user-system interactions, promoting development of useful TM tools, and providing a communication channel between the biocuration and the TM communities. In BioCreative V, the IAT track followed a formatmore » similar to previous interactive tracks, where the utility and usability of TM tools, as well as the generation of use cases, have been the focal points. The proposed curation tasks are user-centric and formally evaluated by biocurators. In BioCreative V IAT, seven TM systems and 43 biocurators participated. Two levels of user participation were offered to broaden curator involvement and obtain more feedback on usability aspects. The full level participation involved training on the system, curation of a set of documents with and without TM assistance, tracking of time-on-task, and completion of a user survey. Here, the partial level participation was designed to focus on usability aspects of the interface and not the performance per se. In this case, biocurators navigated the system by performing pre-designed tasks and then were asked whether they were able to achieve the task and the level of difficulty in completing the task. In this manuscript, we describe the development of the interactive task, from planning to execution and discuss major findings for the systems tested.« less

Human-Vehicle Interface for Semi-Autonomous Operation of Uninhabited Aero Vehicles

NASA Technical Reports Server (NTRS)

Jones, Henry L.; Frew, Eric W.; Woodley, Bruce R.; Rock, Stephen M.

2001-01-01

The robustness of autonomous robotic systems to unanticipated circumstances is typically insufficient for use in the field. The many skills of human user often fill this gap in robotic capability. To incorporate the human into the system, a useful interaction between man and machine must exist. This interaction should enable useful communication to be exchanged in a natural way between human and robot on a variety of levels. This report describes the current human-robot interaction for the Stanford HUMMINGBIRD autonomous helicopter. In particular, the report discusses the elements of the system that enable multiple levels of communication. An intelligent system agent manages the different inputs given to the helicopter. An advanced user interface gives the user and helicopter a method for exchanging useful information. Using this human-robot interaction, the HUMMINGBIRD has carried out various autonomous search, tracking, and retrieval missions.

A conceptual network model of the air transportation system. the basic level 1 model.

DOT National Transportation Integrated Search

1971-04-01

A basic conceptual model of the entire Air Transportation System is being developed to serve as an analytical tool for studying the interactions among the system elements. The model is being designed to function in an interactive computer graphics en...

The Population Inversion and the Entropy of a Moving Two-Level Atom in Interaction with a Quantized Field

NASA Astrophysics Data System (ADS)

Abo-Kahla, D. A. M.; Abdel-Aty, M.; Farouk, A.

2018-05-01

An atom with only two energy eigenvalues is described by a two-dimensional state space spanned by the two energy eigenstates is called a two-level atom. We consider the interaction between a two-level atom system with a constant velocity. An analytic solution of the systems which interacts with a quantized field is provided. Furthermore, the significant effect of the temperature on the atomic inversion, the purity and the information entropy are discussed in case of the initial state either an exited state or a maximally mixed state. Additionally, the effect of the half wavelengths number of the field-mode is investigated.

Effects of interactive instructional techniques in a web-based peripheral nervous system component for human anatomy.

PubMed

Allen, Edwin B; Walls, Richard T; Reilly, Frank D

2008-02-01

This study investigated the effects of interactive instructional techniques in a web-based peripheral nervous system (PNS) component of a first year medical school human anatomy course. Existing data from 9 years of instruction involving 856 students were used to determine (1) the effect of web-based interactive instructional techniques on written exam item performance and (2) differences between student opinions of the benefit level of five different types of interactive learning objects used. The interactive learning objects included Patient Case studies, review Games, Simulated Interactive Patients (SIP), Flashcards, and unit Quizzes. Exam item analysis scores were found to be significantly higher (p < 0.05) for students receiving the instructional treatment incorporating the web-based interactive learning objects than for students not receiving this treatment. Questionnaires using a five-point Likert scale were analysed to determine student opinion ratings of the interactive learning objects. Students reported favorably on the benefit level of all learning objects. Students rated the benefit level of the Simulated Interactive Patients (SIP) highest, and this rating was significantly higher (p < 0.05) than all other learning objects. This study suggests that web-based interactive instructional techniques improve student exam performance. Students indicated a strong acceptance of Simulated Interactive Patient learning objects.

Network representations of immune system complexity

PubMed Central

Subramanian, Naeha; Torabi-Parizi, Parizad; Gottschalk, Rachel A.; Germain, Ronald N.; Dutta, Bhaskar

2015-01-01

The mammalian immune system is a dynamic multi-scale system composed of a hierarchically organized set of molecular, cellular and organismal networks that act in concert to promote effective host defense. These networks range from those involving gene regulatory and protein-protein interactions underlying intracellular signaling pathways and single cell responses to increasingly complex networks of in vivo cellular interaction, positioning and migration that determine the overall immune response of an organism. Immunity is thus not the product of simple signaling events but rather non-linear behaviors arising from dynamic, feedback-regulated interactions among many components. One of the major goals of systems immunology is to quantitatively measure these complex multi-scale spatial and temporal interactions, permitting development of computational models that can be used to predict responses to perturbation. Recent technological advances permit collection of comprehensive datasets at multiple molecular and cellular levels while advances in network biology support representation of the relationships of components at each level as physical or functional interaction networks. The latter facilitate effective visualization of patterns and recognition of emergent properties arising from the many interactions of genes, molecules, and cells of the immune system. We illustrate the power of integrating ‘omics’ and network modeling approaches for unbiased reconstruction of signaling and transcriptional networks with a focus on applications involving the innate immune system. We further discuss future possibilities for reconstruction of increasingly complex cellular and organism-level networks and development of sophisticated computational tools for prediction of emergent immune behavior arising from the concerted action of these networks. PMID:25625853

Hydrographs Showing Groundwater Level Changes for Selected Wells in the Chambers-Clover Creek Watershed and Vicinity, Pierce County, Washington

USGS Publications Warehouse

Justin, G.B.; Julich, R.; Payne, K.L.

2009-01-01

Selected groundwater level hydrographs for the Chambers-Clover Creek watershed (CCCW) and vicinity, Washington, are presented in an interactive web-based map to illustrate changes in groundwater levels in and near the CCCW on a monthly and seasonal basis. Hydrographs are linked to points corresponding to the well location on an interactive map of the study area. Groundwater level data and well information from Federal, State, and local agencies were obtained from the U.S. Geological Survey National Water Information System (NWIS), Groundwater Site Inventory (GWSI) System.

Thyroid-adrenergic interactions: physiological and clinical implications.

PubMed

Silva, J Enrique; Bianco, Suzy D C

2008-02-01

The sympathoadrenal system, including the sympathetic nervous system and the adrenal medulla, interacts with thyroid hormone (TH) at various levels. Both systems are evolutionary old and regulate independent functions, playing probably independent roles in poikilothermic species. With the advent of homeothermy, TH acquired a new role, which is to stimulate thermogenic mechanisms and synergize with the sympathoadrenal system to produce heat and maintain body temperature. An important part of this new function is mediated through coordinated and, most of the time, synergistic interactions with the sympathoadrenal system. Catecholamines can in turn activate TH in a tissue-specific manner, most notably in brown adipose tissue. Such interactions are of great adaptive value in cold adaptation and in states needing high-energy output. Conversely, in states of emergency where energy demand should be reduced, such as disease and starvation, both systems are turned down. In pathological states, where one of the systems is fixed at a high or a low level, coordination is lost with disruption of the physiology and development of symptoms. Exaggerated responses to catecholamines dominate the manifestations of thyrotoxicosis, while hypothyroidism is characterized by a narrowing of adaptive responses (e.g., thermogenic, cardiovascular, and lipolytic). Finally, emerging results suggest the possibility that disrupted interactions between the two systems contribute to explain metabolic variability, for example, fuel efficiency, energy expenditure, and lipolytic responses.

Query2Question: Translating Visualization Interaction into Natural Language.

PubMed

Nafari, Maryam; Weaver, Chris

2015-06-01

Richly interactive visualization tools are increasingly popular for data exploration and analysis in a wide variety of domains. Existing systems and techniques for recording provenance of interaction focus either on comprehensive automated recording of low-level interaction events or on idiosyncratic manual transcription of high-level analysis activities. In this paper, we present the architecture and translation design of a query-to-question (Q2Q) system that automatically records user interactions and presents them semantically using natural language (written English). Q2Q takes advantage of domain knowledge and uses natural language generation (NLG) techniques to translate and transcribe a progression of interactive visualization states into a visual log of styled text that complements and effectively extends the functionality of visualization tools. We present Q2Q as a means to support a cross-examination process in which questions rather than interactions are the focus of analytic reasoning and action. We describe the architecture and implementation of the Q2Q system, discuss key design factors and variations that effect question generation, and present several visualizations that incorporate Q2Q for analysis in a variety of knowledge domains.

On the equilibrium state of a small system with random matrix coupling to its environment

NASA Astrophysics Data System (ADS)

Lebowitz, J. L.; Pastur, L.

2015-07-01

We consider a random matrix model of interaction between a small n-level system, S, and its environment, a N-level heat reservoir, R. The interaction between S and R is modeled by a tensor product of a fixed n× n matrix and a N× N Hermitian random matrix. We show that under certain ‘macroscopicity’ conditions on R, the reduced density matrix of the system {{ρ }S}=T{{r}R}ρ S\\cup R(eq), is given by ρ S(c)˜ exp \\{-β {{H}S}\\}, where HS is the Hamiltonian of the isolated system. This holds for all strengths of the interaction and thus gives some justification for using ρ S(c) to describe some nano-systems, like biopolymers, in equilibrium with their environment (Seifert 2012 Rep. Prog. Phys. 75 126001). Our results extend those obtained previously in (Lebowitz and Pastur 2004 J. Phys. A: Math. Gen. 37 1517-34) (Lebowitz et al 2007 Contemporary Mathematics (Providence RI: American Mathematical Society) pp 199-218) for a special two-level system.

Interactive classification and content-based retrieval of tissue images

NASA Astrophysics Data System (ADS)

Aksoy, Selim; Marchisio, Giovanni B.; Tusk, Carsten; Koperski, Krzysztof

2002-11-01

We describe a system for interactive classification and retrieval of microscopic tissue images. Our system models tissues in pixel, region and image levels. Pixel level features are generated using unsupervised clustering of color and texture values. Region level features include shape information and statistics of pixel level feature values. Image level features include statistics and spatial relationships of regions. To reduce the gap between low-level features and high-level expert knowledge, we define the concept of prototype regions. The system learns the prototype regions in an image collection using model-based clustering and density estimation. Different tissue types are modeled using spatial relationships of these regions. Spatial relationships are represented by fuzzy membership functions. The system automatically selects significant relationships from training data and builds models which can also be updated using user relevance feedback. A Bayesian framework is used to classify tissues based on these models. Preliminary experiments show that the spatial relationship models we developed provide a flexible and powerful framework for classification and retrieval of tissue images.

Time-Ordered Networks Reveal Limitations to Information Flow in Ant Colonies

PubMed Central

Blonder, Benjamin; Dornhaus, Anna

2011-01-01

Background An important function of many complex networks is to inhibit or promote the transmission of disease, resources, or information between individuals. However, little is known about how the temporal dynamics of individual-level interactions affect these networks and constrain their function. Ant colonies are a model comparative system for understanding general principles linking individual-level interactions to network-level functions because interactions among individuals enable integration of multiple sources of information to collectively make decisions, and allocate tasks and resources. Methodology/Findings Here we show how the temporal and spatial dynamics of such individual interactions provide upper bounds to rates of colony-level information flow in the ant Temnothorax rugatulus. We develop a general framework for analyzing dynamic networks and a mathematical model that predicts how information flow scales with individual mobility and group size. Conclusions/Significance Using thousands of time-stamped interactions between uniquely marked ants in four colonies of a range of sizes, we demonstrate that observed maximum rates of information flow are always slower than predicted, and are constrained by regulation of individual mobility and contact rate. By accounting for the ordering and timing of interactions, we can resolve important difficulties with network sampling frequency and duration, enabling a broader understanding of interaction network functioning across systems and scales. PMID:21625450

The emerging genomics and systems biology research lead to systems genomics studies.

PubMed

Yang, Mary Qu; Yoshigoe, Kenji; Yang, William; Tong, Weida; Qin, Xiang; Dunker, A; Chen, Zhongxue; Arbania, Hamid R; Liu, Jun S; Niemierko, Andrzej; Yang, Jack Y

2014-01-01

Synergistically integrating multi-layer genomic data at systems level not only can lead to deeper insights into the molecular mechanisms related to disease initiation and progression, but also can guide pathway-based biomarker and drug target identification. With the advent of high-throughput next-generation sequencing technologies, sequencing both DNA and RNA has generated multi-layer genomic data that can provide DNA polymorphism, non-coding RNA, messenger RNA, gene expression, isoform and alternative splicing information. Systems biology on the other hand studies complex biological systems, particularly systematic study of complex molecular interactions within specific cells or organisms. Genomics and molecular systems biology can be merged into the study of genomic profiles and implicated biological functions at cellular or organism level. The prospectively emerging field can be referred to as systems genomics or genomic systems biology. The Mid-South Bioinformatics Centre (MBC) and Joint Bioinformatics Ph.D. Program of University of Arkansas at Little Rock and University of Arkansas for Medical Sciences are particularly interested in promoting education and research advancement in this prospectively emerging field. Based on past investigations and research outcomes, MBC is further utilizing differential gene and isoform/exon expression from RNA-seq and co-regulation from the ChiP-seq specific for different phenotypes in combination with protein-protein interactions, and protein-DNA interactions to construct high-level gene networks for an integrative genome-phoneme investigation at systems biology level.

Low eigenvalues of the entanglement Hamiltonian, localization length, and rare regions in one-dimensional disordered interacting systems

NASA Astrophysics Data System (ADS)

Berkovits, Richard

2018-03-01

The properties of the low-lying eigenvalues of the entanglement Hamiltonian and their relation to the localization length of a disordered interacting one-dimensional many-particle system are studied. The average of the first entanglement Hamiltonian level spacing is proportional to the ground-state localization length and shows the same dependence on the disorder and interaction strength as the localization length. This is the result of the fact that entanglement is limited to distances of order of the localization length. The distribution of the first entanglement level spacing shows a Gaussian-type behavior as expected for level spacings much larger than the disorder broadening. For weakly disordered systems (localization length larger than sample length), the distribution shows an additional peak at low-level spacings. This stems from rare regions in some samples which exhibit metalliclike behavior of large entanglement and large particle-number fluctuations. These intermediate microemulsion metallic regions embedded in the insulating phase are discussed.

Introducing WISDEM:An Integrated System Modeling for Wind Turbines and Plant (Presentation)

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

Dykes, K.; Graf, P.; Scott, G.

2015-01-01

The National Wind Technology Center wind energy systems engineering initiative has developed an analysis platform to leverage its research capabilities toward integrating wind energy engineering and cost models across wind plants. This Wind-Plant Integrated System Design & Engineering Model (WISDEM) platform captures the important interactions between various subsystems to achieve a better National Wind Technology Center wind energy systems engineering initiative has developed an analysis platform to leverage its research capabilities toward integrating wind energy engineering and cost models across wind plants. This Wind-Plant Integrated System Design & Engineering Model (WISDEM) platform captures the important interactions between various subsystems tomore » achieve a better understanding of how to improve system-level performance and achieve system-level cost reductions. This work illustrates a few case studies with WISDEM that focus on the design and analysis of wind turbines and plants at different system levels.« less

Superradiant phase transition in a model of three-level-Λ systems interacting with two bosonic modes

NASA Astrophysics Data System (ADS)

Hayn, Mathias; Emary, Clive; Brandes, Tobias

2012-12-01

We consider an ensemble of three-level particles in Lambda configuration interacting with two bosonic modes. The Hamiltonian has the form of a generalized Dicke model. We show that in the thermodynamic limit this model supports a superradiant quantum phase transition. Remarkably, this can be both a first- and a second-order phase transition. A connection of the phase diagram to the symmetries of the Hamiltonian is also given. In addition, we show that this model can describe atoms interacting with an electromagnetic field in which the microscopic Hamiltonian includes a diamagnetic contribution. Even though the parameters of the atomic system respect the Thomas-Reiche-Kuhn sum rule, the system still shows a superradiant phase transition.

Quantum chaos and breaking of all anti-unitary symmetries in Rydberg excitons.

PubMed

Aßmann, Marc; Thewes, Johannes; Fröhlich, Dietmar; Bayer, Manfred

2016-07-01

Symmetries are the underlying principles of fundamental interactions in nature. Chaos in a quantum system may emerge from breaking these symmetries. Compared to vacuum, crystals are attractive for studying quantum chaos, as they not only break spatial isotropy, but also lead to novel quasiparticles with modified interactions. Here we study yellow Rydberg excitons in cuprous oxide which couple strongly to the vacuum light field and interact significantly with crystal phonons, leading to inversion symmetry breaking. In a magnetic field, time-reversal symmetry is also broken and the exciton states show a complex splitting pattern, resulting in quadratic level repulsion for small splittings. In contrast to atomic chaotic systems in a magnetic field, which show only a linear level repulsion, this is a signature of a system where all anti-unitary symmetries are broken simultaneously. This behaviour can otherwise be found only for the electro-weak interaction or engineered billiards.

The research of distributed interactive simulation based on HLA in coal mine industry inherent safety

NASA Astrophysics Data System (ADS)

Dou, Zhi-Wu

2010-08-01

To solve the inherent safety problem puzzling the coal mining industry, analyzing the characteristic and the application of distributed interactive simulation based on high level architecture (DIS/HLA), a new method is proposed for developing coal mining industry inherent safety distributed interactive simulation adopting HLA technology. Researching the function and structure of the system, a simple coal mining industry inherent safety is modeled with HLA, the FOM and SOM are developed, and the math models are suggested. The results of the instance research show that HLA plays an important role in developing distributed interactive simulation of complicated distributed system and the method is valid to solve the problem puzzling coal mining industry. To the coal mining industry, the conclusions show that the simulation system with HLA plays an important role to identify the source of hazard, to make the measure for accident, and to improve the level of management.

Extended GTST-MLD for aerospace system safety analysis.

PubMed

Guo, Chiming; Gong, Shiyu; Tan, Lin; Guo, Bo

2012-06-01

The hazards caused by complex interactions in the aerospace system have become a problem that urgently needs to be settled. This article introduces a method for aerospace system hazard interaction identification based on extended GTST-MLD (goal tree-success tree-master logic diagram) during the design stage. GTST-MLD is a functional modeling framework with a simple architecture. Ontology is used to extend the ability of system interaction description in GTST-MLD by adding the system design knowledge and the past accident experience. From the level of functionality and equipment, respectively, this approach can help the technician detect potential hazard interactions. Finally, a case is used to show the method. © 2011 Society for Risk Analysis.

Structure-Function Relations in Physiology Education: Where's the Mechanism?

ERIC Educational Resources Information Center

Lira, Matthew E.; Gardner, Stephanie M.

2017-01-01

Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such…

The Development and Initial Evaluation of the Human Readiness Level Framework

DTIC Science & Technology

2010-06-01

View ICD Initial Capabilities Document ICW Interactive Course Ware ILE Interactive Learning Environment ILT Instructor Led Training IOC...Programmatic Environmental Safety and Health Evaluation PHA Preliminary Hazard Analysis PHL Preliminary Hazard List xiv PM Program Manager PQS...Occupational Health SOW Statement of Work SRD System Requirements Document SPS System Performance Specification SRR System Requirements Review SVR

Interactions between neural networks: a mechanism for tuning chaos and oscillations.

PubMed

Wang, Lipo

2007-06-01

We show that chaos and oscillations in a higher-order binary neural network can be tuned effectively using interactions between neural networks. Our results suggest that network interactions may be useful as a means of adjusting the level of dynamic activities in systems that employ chaos and oscillations for information processing, or as a means of suppressing oscillatory behaviors in systems that require stability.

Overview of the interactive task in BioCreative V.

PubMed

Wang, Qinghua; S Abdul, Shabbir; Almeida, Lara; Ananiadou, Sophia; Balderas-Martínez, Yalbi I; Batista-Navarro, Riza; Campos, David; Chilton, Lucy; Chou, Hui-Jou; Contreras, Gabriela; Cooper, Laurel; Dai, Hong-Jie; Ferrell, Barbra; Fluck, Juliane; Gama-Castro, Socorro; George, Nancy; Gkoutos, Georgios; Irin, Afroza K; Jensen, Lars J; Jimenez, Silvia; Jue, Toni R; Keseler, Ingrid; Madan, Sumit; Matos, Sérgio; McQuilton, Peter; Milacic, Marija; Mort, Matthew; Natarajan, Jeyakumar; Pafilis, Evangelos; Pereira, Emiliano; Rao, Shruti; Rinaldi, Fabio; Rothfels, Karen; Salgado, David; Silva, Raquel M; Singh, Onkar; Stefancsik, Raymund; Su, Chu-Hsien; Subramani, Suresh; Tadepally, Hamsa D; Tsaprouni, Loukia; Vasilevsky, Nicole; Wang, Xiaodong; Chatr-Aryamontri, Andrew; Laulederkind, Stanley J F; Matis-Mitchell, Sherri; McEntyre, Johanna; Orchard, Sandra; Pundir, Sangya; Rodriguez-Esteban, Raul; Van Auken, Kimberly; Lu, Zhiyong; Schaeffer, Mary; Wu, Cathy H; Hirschman, Lynette; Arighi, Cecilia N

2016-01-01

Fully automated text mining (TM) systems promote efficient literature searching, retrieval, and review but are not sufficient to produce ready-to-consume curated documents. These systems are not meant to replace biocurators, but instead to assist them in one or more literature curation steps. To do so, the user interface is an important aspect that needs to be considered for tool adoption. The BioCreative Interactive task (IAT) is a track designed for exploring user-system interactions, promoting development of useful TM tools, and providing a communication channel between the biocuration and the TM communities. In BioCreative V, the IAT track followed a format similar to previous interactive tracks, where the utility and usability of TM tools, as well as the generation of use cases, have been the focal points. The proposed curation tasks are user-centric and formally evaluated by biocurators. In BioCreative V IAT, seven TM systems and 43 biocurators participated. Two levels of user participation were offered to broaden curator involvement and obtain more feedback on usability aspects. The full level participation involved training on the system, curation of a set of documents with and without TM assistance, tracking of time-on-task, and completion of a user survey. The partial level participation was designed to focus on usability aspects of the interface and not the performance per se In this case, biocurators navigated the system by performing pre-designed tasks and then were asked whether they were able to achieve the task and the level of difficulty in completing the task. In this manuscript, we describe the development of the interactive task, from planning to execution and discuss major findings for the systems tested.Database URL: http://www.biocreative.org. Published by Oxford University Press 2016. This work is written by US Government employees and is in the public domain in the US.

Effect of the magnetic dipole interaction on a spin-1 system

NASA Astrophysics Data System (ADS)

Hu, Fangqi; Jia, Wei; Zhao, Qing

2018-05-01

We consider a hybrid system composed of a spin-1 triplet coupled to a nuclear spin. We study the effect of the axisymmetric and the quadrupole term of the magnetic dipole interaction between the two electrons forming the triplet on the energy spectrum in a static magnetic field. The energy spectrum obtained by directly diagonalizing the Hamiltonian of the system shows that these two terms not only remove the special crossings that appear in the absence of the magnetic dipole interaction, but also produce new (avoided) crossings by lifting the relevant levels. Specially, the gaps between the avoided crossing levels increase with the strength of the quadrupole term. In order to accurately illustrate these effects, we present the results for the discriminant and von Neumann entropy of one electron interacting with the rest of the whole system. Finally, by numerically solving the time-dependent Schrödinger equations of the system, we discover that the polarization oscillation of electron and nuclear spin is in-phase and the total average longitudinal spin is not conserved at location of avoided crossing, but the two results are opposite beyond that.

Quantum Treatment of Two Coupled Oscillators in Interaction with a Two-Level Atom:

NASA Astrophysics Data System (ADS)

Khalil, E. M.; Abdalla, M. Sebawe; Obada, A. S.-F.

In this communication we handle a modified model representing the interaction between a two-level atom and two modes of the electromagnetic field in a cavity. The interaction between the modes is assumed to be of a parametric amplifier type. The model consists of two different systems, one represents the Jaynes-Cummings model (atom-field interaction) and the other represents the two mode parametric amplifier model (field-field interaction). After some canonical transformations the constants of the motion have been obtained and used to derive the time evolution operator. The wave function in the Schrödinger picture is constructed and employed to discuss some statistical properties related to the system. Further discussion related to the statistical properties of some physical quantities is given where we have taken into account an initial correlated pair-coherent state for the modes. We concentrate in our examination on the system behavior that occurred as a result of the variation of the parametric amplifier coupling parameter as well as the detuning parameter. It has been shown that the interaction of the parametric amplifier term increases the revival period and consequently longer period of strong interaction between the atom and the fields.

Social regulation of emotion: messy layers

PubMed Central

Kappas, Arvid

2013-01-01

Emotions are evolved systems of intra- and interpersonal processes that are regulatory in nature, dealing mostly with issues of personal or social concern. They regulate social interaction and in extension, the social sphere. In turn, processes in the social sphere regulate emotions of individuals and groups. In other words, intrapersonal processes project in the interpersonal space, and inversely, interpersonal experiences deeply influence intrapersonal processes. Thus, I argue that the concepts of emotion generation and regulation should not be artificially separated. Similarly, interpersonal emotions should not be reduced to interacting systems of intraindividual processes. Instead, we can consider emotions at different social levels, ranging from dyads to large scale e-communities. The interaction between these levels is complex and does not only involve influences from one level to the next. In this sense the levels of emotion/regulation are messy and a challenge for empirical study. In this article, I discuss the concepts of emotions and regulation at different intra- and interpersonal levels. I extend the concept of auto-regulation of emotions (Kappas, 2008, 2011a,b) to social processes. Furthermore, I argue for the necessity of including mediated communication, particularly in cyberspace in contemporary models of emotion/regulation. Lastly, I suggest the use of concepts from systems dynamics and complex systems to tackle the challenge of the “messy layers.” PMID:23424049

Learner Control in Hypermedia Environments

ERIC Educational Resources Information Center

Scheiter, Katharina; Gerjets, Peter

2007-01-01

Contrary to system-controlled multimedia learning environments, hypermedia systems are characterized by a high level of interactivity. This interactivity is referred to as learner control in the respective literature. For several reasons this learner control is seen as a major advantage of hypermedia for learning and instruction. For instance,…

Quantum phases of a three-level matter-radiation interaction model using SU(3) coherent states with different cooperation numbers

NASA Astrophysics Data System (ADS)

Quezada, L. F.; Nahmad-Achar, E.

2018-06-01

We use coherent states as trial states for a variational approach to study a system of a finite number of three-level atoms interacting in a dipolar approximation with a one-mode electromagnetic field. The atoms are treated as semidistinguishable using different cooperation numbers and representations of SU(3). We focus our analysis on the quantum phases of the system as well as the behavior of the most relevant observables near the phase transitions. The results are computed for all three possible configurations (Ξ , Λ , and V ) of the three-level atoms.

Wind Turbine Optimization with WISDEM

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

Dykes, Katherine L; Damiani, Rick R; Graf, Peter A

This presentation for the Fourth Wind Energy Systems Engineering Workshop explains the NREL wind energy systems engineering initiative-developed analysis platform and research capability to capture important system interactions to achieve a better understanding of how to improve system-level performance and achieve system-level cost reductions. Topics include Wind-Plant Integrated System Design and Engineering Model (WISDEM) and multidisciplinary design analysis and optimization.

A Methodology for Multiple Rule System Integration and Resolution Within a Singular Knowledge Base

NASA Technical Reports Server (NTRS)

Kautzmann, Frank N., III

1988-01-01

Expert Systems which support knowledge representation by qualitative modeling techniques experience problems, when called upon to support integrated views embodying description and explanation, especially when other factors such as multiple causality, competing rule model resolution, and multiple uses of knowledge representation are included. A series of prototypes are being developed to demonstrate the feasibility of automating the process of systems engineering, design and configuration, and diagnosis and fault management. A study involves not only a generic knowledge representation; it must also support multiple views at varying levels of description and interaction between physical elements, systems, and subsystems. Moreover, it will involve models of description and explanation for each level. This multiple model feature requires the development of control methods between rule systems and heuristics on a meta-level for each expert system involved in an integrated and larger class of expert system. The broadest possible category of interacting expert systems is described along with a general methodology for the knowledge representation and control of mutually exclusive rule systems.

Multidimensional approaches for studying plant defence against insects: from ecology to omics and synthetic biology.

PubMed

Barah, Pankaj; Bones, Atle M

2015-02-01

The biggest challenge for modern biology is to integrate multidisciplinary approaches towards understanding the organizational and functional complexity of biological systems at different hierarchies, starting from the subcellular molecular mechanisms (microscopic) to the functional interactions of ecological communities (macroscopic). The plant-insect interaction is a good model for this purpose with the availability of an enormous amount of information at the molecular and the ecosystem levels. Changing global climatic conditions are abruptly resetting plant-insect interactions. Integration of discretely located heterogeneous information from the ecosystem to genes and pathways will be an advantage to understand the complexity of plant-insect interactions. This review will present the recent developments in omics-based high-throughput experimental approaches, with particular emphasis on studying plant defence responses against insect attack. The review highlights the importance of using integrative systems approaches to study plant-insect interactions from the macroscopic to the microscopic level. We analyse the current efforts in generating, integrating and modelling multiomics data to understand plant-insect interaction at a systems level. As a future prospect, we highlight the growing interest in utilizing the synthetic biology platform for engineering insect-resistant plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

When high pressure, system constraints, and a social justice mission collide: A socio-structural analysis of emergency department social work services.

PubMed

Moore, Megan; Cristofalo, Margaret; Dotolo, Danae; Torres, Nicole; Lahdya, Alexandra; Ho, Leyna; Vogel, Mia; Forrester, Mollie; Conley, Bonnie; Fouts, Susan

2017-04-01

The emergency department (ED) can be a critical intervention point for many patients with multifaceted needs. Social workers have long been part of interdisciplinary ED teams. This study aimed to contribute to the limited understanding of social worker-patient interactions and factors influencing social work services in this setting. This paper reports a qualitative content analysis of social work medical record notes (N = 1509) of services provided to trauma patients in an urban, public, level 1 trauma center and an in-depth analysis of semi-structured interviews with ED social workers (N = 10). Eight major social work roles were identified: investigator, gatekeeper, resource broker, care coordinator, problem solver, crisis manager, advocate, discharge planner. Analyses revealed a complex interplay between ED social work services and multi-layered contexts. Using a social-ecological framework, we identified the interactions between micro or individual level factors, mezzo or local system level factors and macro environmental and systemic factors that play a role in ED interactions and patient services. Macro-level contextual influences were socio-structural forces including socioeconomic barriers to health, social hierarchies that reflected power differentials between providers and patients, and distrust or bias. Mezzo-level forces were limited resources, lack of healthcare system coordination, a challenging hierarchy within the medical model and the pressure to discharge patients quickly. Micro-level factors included characteristics of patients and social workers, complexity of patient stressors, empathic strain, lack of closure and compassion. All of these forces were at play in patient-social worker interactions and impacted service provision. Social workers were at times able to successfully navigate these forces, yet at other times these challenges were insurmountable. A conceptual model of ED social work and the influences on the patient-social worker interactions was developed to assist in guiding innovative research and practice models to improve services and outcomes in the complex, fast-paced ED. Copyright © 2017 Elsevier Ltd. All rights reserved.

When high pressure, system constraints, and a social justice mission collide: a socio-structural analysis of emergency department social work services

PubMed Central

Cristofalo, Margaret; Dotolo, Danae; Torres, Nicole; Lahdya, Alexandra; Ho, Leyna; Vogel, Mia; Forrester, Mollie; Conley, Bonnie; Fouts, Susan

2017-01-01

The emergency department (ED) can be a critical intervention point for many patients with multifaceted needs. Social workers have long been part of interdisciplinary ED teams. This study aimed to contribute to the limited understanding of social worker-patient interactions and factors influencing social work services in this setting. This paper reports a qualitative content analysis of social work medical record notes (N=1,509) of services provided to trauma patients in an urban, public, level 1 trauma center and an in-depth analysis of semi-structured interviews with ED social workers (N=10). Eight major social work roles were identified: investigator, gatekeeper, resource broker, care coordinator, problem solver, crisis manager, advocate, discharge planner. Analyses revealed a complex interplay between ED social work services and multi-layered contexts. Using a social-ecological framework, we identified the interactions between micro or individual level factors, mezzo or local system level factors and macro environmental and systemic factors that play a role in ED interactions and patient services. Macro-level contextual influences were socio-structural forces including socioeconomic barriers to health, social hierarchies that reflected power differentials between providers and patients, and distrust or bias. Mezzo-level forces were limited resources, lack of healthcare system coordination, a challenging hierarchy within the medical model and the pressure to discharge patients quickly. Micro-level factors included characteristics of patients and social workers, complexity of patient stressors, empathic strain, lack of closure and compassion. All of these forces were at play in patient-social worker interactions and impacted service provision. Social workers were at times able to successfully navigate these forces, yet at other times these challenges were insurmountable. A conceptual model of ED social work and the influences on the patient-social worker interactions was developed to assist in guiding innovative research and practice models to improve services and outcomes in the complex, fast-paced ED. PMID:28214722

Designing, Testing and Using Command, Control, Communications, Computer, and Intelligence (C4I) Systems: What Causes the Disconnects and What Can Be Done About Them?

DTIC Science & Technology

1994-06-01

numbers on a Cathode Ray Tube (CRT) visual display or monochrome monitor. Gradually, pictures and color were added to enhance this interaction...apparent that there are very strong interactions among the political, economic, and military aspects of national power. Although the NCA will...classified according to the levels of war. Which level of war best describes your experience with C4I systems? Strategic - NCA (Nuclear) Operational

The Automation-by-Expertise-by-Training Interaction.

PubMed

Strauch, Barry

2017-03-01

I introduce the automation-by-expertise-by-training interaction in automated systems and discuss its influence on operator performance. Transportation accidents that, across a 30-year interval demonstrated identical automation-related operator errors, suggest a need to reexamine traditional views of automation. I review accident investigation reports, regulator studies, and literature on human computer interaction, expertise, and training and discuss how failing to attend to the interaction of automation, expertise level, and training has enabled operators to commit identical automation-related errors. Automated systems continue to provide capabilities exceeding operators' need for effective system operation and provide interfaces that can hinder, rather than enhance, operator automation-related situation awareness. Because of limitations in time and resources, training programs do not provide operators the expertise needed to effectively operate these automated systems, requiring them to obtain the expertise ad hoc during system operations. As a result, many do not acquire necessary automation-related system expertise. Integrating automation with expected operator expertise levels, and within training programs that provide operators the necessary automation expertise, can reduce opportunities for automation-related operator errors. Research to address the automation-by-expertise-by-training interaction is needed. However, such research must meet challenges inherent to examining realistic sociotechnical system automation features with representative samples of operators, perhaps by using observational and ethnographic research. Research in this domain should improve the integration of design and training and, it is hoped, enhance operator performance.

Effective Levels of Adaptation to Different Types of Users in Interactive Museum Systems.

ERIC Educational Resources Information Center

Paterno, F.; Mancini, C.

2000-01-01

Discusses user interaction with museum application interfaces and emphasizes the importance of adaptable and adaptive interfaces to meet differing user needs. Considers levels of support that can be given to different users during navigation of museum hypermedia information, using examples from the Web site for the Marble Museum (Italy).…

A Multimedia, Augmented Reality Interactive System for the Application of a Guided School Tour

NASA Astrophysics Data System (ADS)

Lin, Ko-Chun; Huang, Sheng-Wen; Chu, Sheng-Kai; Su, Ming-Wei; Chen, Chia-Yen; Chen, Chi-Fa

The paper describes an implementation of a multimedia, augmented reality system used for a guided school tour. The aim of this work is to improve the level of interactions between a viewer and the system by means of augmented reality. In the implemented system, hand motions are captured via computer vision based approaches and analyzed to extract representative actions which are used to interact with the system. In this manner, tactile peripheral hardware such as keyboard and mouse can be eliminated. In addition, the proposed system also aims to reduce hardware related costs and avoid health risks associated with contaminations by contact in public areas.

Control, responses and modularity of cellular regulatory networks: a control analysis perspective.

PubMed

Bruggeman, F J; Snoep, J L; Westerhoff, H V

2008-11-01

Cells adapt to changes in environmental conditions through the concerted action of signalling, gene expression and metabolic subsystems. The authors will discuss a theoretical framework addressing such integrated systems. This 'hierarchical analysis' was first developed as an extension to a metabolic control analysis. It builds on the phenomenon that often the communication between signalling, gene expression and metabolic subsystems is almost exclusively via regulatory interactions and not via mass flow interactions. This allows for the treatment of the said subsystems as 'levels' in a hierarchical view of the organisation of the molecular reaction network of cells. Such a hierarchical approach has as a major advantage that levels can be analysed conceptually in isolation of each other (from a local intra-level perspective) and at a later stage integrated via their interactions (from a global inter-level perspective). Hereby, it allows for a modular approach with variable scope. A number of different approaches have been developed for the analysis of hierarchical systems, for example hierarchical control analysis and modular response analysis. The authors, here, review these methods and illustrate the strength of these types of analyses using a core model of a system with gene expression, metabolic and signal transduction levels.

LUMIS Interactive graphics operating instructions and system specifications

NASA Technical Reports Server (NTRS)

Bryant, N. A.; Yu, T. C.; Landini, A. J.

1976-01-01

The LUMIS program has designed an integrated geographic information system to assist program managers and planning groups in metropolitan regions. Described is the system designed to interactively interrogate a data base, display graphically a portion of the region enclosed in the data base, and perform cross tabulations of variables within each city block, block group, or census tract. The system is designed to interface with U. S. Census DIME file technology, but can accept alternative districting conventions. The system is described on three levels: (1) introduction to the systems's concept and potential applications; (2) the method of operating the system on an interactive terminal; and (3) a detailed system specification for computer facility personnel.

Modeling joint restoration strategies for interdependent infrastructure systems.

PubMed

Zhang, Chao; Kong, Jingjing; Simonovic, Slobodan P

2018-01-01

Life in the modern world depends on multiple critical services provided by infrastructure systems which are interdependent at multiple levels. To effectively respond to infrastructure failures, this paper proposes a model for developing optimal joint restoration strategy for interdependent infrastructure systems following a disruptive event. First, models for (i) describing structure of interdependent infrastructure system and (ii) their interaction process, are presented. Both models are considering the failure types, infrastructure operating rules and interdependencies among systems. Second, an optimization model for determining an optimal joint restoration strategy at infrastructure component level by minimizing the economic loss from the infrastructure failures, is proposed. The utility of the model is illustrated using a case study of electric-water systems. Results show that a small number of failed infrastructure components can trigger high level failures in interdependent systems; the optimal joint restoration strategy varies with failure occurrence time. The proposed models can help decision makers to understand the mechanisms of infrastructure interactions and search for optimal joint restoration strategy, which can significantly enhance safety of infrastructure systems.

Ecological hierarchies and self-organisation - Pattern analysis, modelling and process integration across scales

USGS Publications Warehouse

Reuter, H.; Jopp, F.; Blanco-Moreno, J. M.; Damgaard, C.; Matsinos, Y.; DeAngelis, D.L.

2010-01-01

A continuing discussion in applied and theoretical ecology focuses on the relationship of different organisational levels and on how ecological systems interact across scales. We address principal approaches to cope with complex across-level issues in ecology by applying elements of hierarchy theory and the theory of complex adaptive systems. A top-down approach, often characterised by the use of statistical techniques, can be applied to analyse large-scale dynamics and identify constraints exerted on lower levels. Current developments are illustrated with examples from the analysis of within-community spatial patterns and large-scale vegetation patterns. A bottom-up approach allows one to elucidate how interactions of individuals shape dynamics at higher levels in a self-organisation process; e.g., population development and community composition. This may be facilitated by various modelling tools, which provide the distinction between focal levels and resulting properties. For instance, resilience in grassland communities has been analysed with a cellular automaton approach, and the driving forces in rodent population oscillations have been identified with an agent-based model. Both modelling tools illustrate the principles of analysing higher level processes by representing the interactions of basic components.The focus of most ecological investigations on either top-down or bottom-up approaches may not be appropriate, if strong cross-scale relationships predominate. Here, we propose an 'across-scale-approach', closely interweaving the inherent potentials of both approaches. This combination of analytical and synthesising approaches will enable ecologists to establish a more coherent access to cross-level interactions in ecological systems. ?? 2010 Gesellschaft f??r ??kologie.

Interactions between neural networks: a mechanism for tuning chaos and oscillations

PubMed Central

2007-01-01

We show that chaos and oscillations in a higher-order binary neural network can be tuned effectively using interactions between neural networks. Our results suggest that network interactions may be useful as a means of adjusting the level of dynamic activities in systems that employ chaos and oscillations for information processing, or as a means of suppressing oscillatory behaviors in systems that require stability. PMID:19003511

Emergence of liquid crystalline order in the lowest Landau level of a quantum Hall system with internal anisotropy

NASA Astrophysics Data System (ADS)

Ciftja, Orion

2018-05-01

It has now become evident that interplay between internal anisotropy parameters (such as electron mass anisotropy and/or anisotropic coupling of electrons to the substrate) and electron-electron correlation effects can create a rich variety of possibilities especially in quantum Hall systems. The electron mass anisotropy or material substrate effects (for example, the piezoelectric effect in GaAs) can lead to an effective anisotropic interaction potential between electrons. For lack of knowledge of realistic ab-initio potentials that may describe such effects, we adopt a phenomenological approach and assume that an anisotropic Coulomb interaction potential mimics the internal anisotropy of the system. In this work we investigate the emergence of liquid crystalline order at filling factor ν = 1/6 of the lowest Landau level, a state very close to the point where a transition from the liquid to the Wigner solid happens. We consider small finite systems of electrons interacting with an anisotropic Coulomb interaction potential and study the energy stability of an anisotropic liquid crystalline state relative to its isotropic Fermi-liquid counterpart. Quantum Monte Carlo simulation results in disk geometry show stabilization of liquid crystalline order driven by an anisotropic Coulomb interaction potential at all values of the interaction anisotropy parameter studied.

Systems and methods for interactive virtual reality process control and simulation

DOEpatents

Daniel, Jr., William E.; Whitney, Michael A.

2001-01-01

A system for visualizing, controlling and managing information includes a data analysis unit for interpreting and classifying raw data using analytical techniques. A data flow coordination unit routes data from its source to other components within the system. A data preparation unit handles the graphical preparation of the data and a data rendering unit presents the data in a three-dimensional interactive environment where the user can observe, interact with, and interpret the data. A user can view the information on various levels, from a high overall process level view, to a view illustrating linkage between variables, to view the hard data itself, or to view results of an analysis of the data. The system allows a user to monitor a physical process in real-time and further allows the user to manage and control the information in a manner not previously possible.

Water resources planning based on complex system dynamics: A case study of Tianjin city

NASA Astrophysics Data System (ADS)

Zhang, X. H.; Zhang, H. W.; Chen, B.; Chen, G. Q.; Zhao, X. H.

2008-12-01

A complex system dynamic (SD) model focusing on water resources, termed as TianjinSD, is developed for the integrated and scientific management of the water resources of Tianjin, which contains information feedback that governs interactions in the system and is capable of synthesizing component-level knowledge into system behavior simulation at an integrated level, thus presenting reasonable predictive results for policy-making on water resources allocation and management. As for the Tianjin city, interactions among 96 components for 12 years are explored and four planning alternatives are chosen, one of which is based on the conventional mode assuming that the existing pattern of human activities will be prevailed, while the others are alternative planning designs based on the interaction of local authorities and planning researchers. Optimal mode is therefore obtained according to different scenarios when compared the simulation results for evaluation of different decisions and dynamic consequences.

Study of multi-level atomic systems with the application of magnetic field

NASA Astrophysics Data System (ADS)

Hu, Jianping; Roy, Subhankar; Ummal Momeen, M.

2018-04-01

The complexity of multiple energy levels associated with each atomic system determines the various processes related to light- matter interactions. It is necessary to understand the influence of different levels in a given atomic system. In this work we focus on multi- level atomic schemes with the application of magnetic field. We analyze the different EIT windows which appears in the presence of moderately high magnetic field (∼ 10 G) strength.

Loss of functionally unique species may gradually undermine ecosystems

PubMed Central

O'Gorman, Eoin J.; Yearsley, Jon M.; Crowe, Tasman P.; Emmerson, Mark C.; Jacob, Ute; Petchey, Owen L.

2011-01-01

Functionally unique species contribute to the functional diversity of natural systems, often enhancing ecosystem functioning. An abundance of weakly interacting species increases stability in natural systems, suggesting that loss of weakly linked species may reduce stability. Any link between the functional uniqueness of a species and the strength of its interactions in a food web could therefore have simultaneous effects on ecosystem functioning and stability. Here, we analyse patterns in 213 real food webs and show that highly unique species consistently tend to have the weakest mean interaction strength per unit biomass in the system. This relationship is not a simple consequence of the interdependence of both measures on body size and appears to be driven by the empirical pattern of size structuring in aquatic systems and the trophic position of each species in the web. Food web resolution also has an important effect, with aggregation of species into higher taxonomic groups producing a much weaker relationship. Food webs with fewer unique and less weakly interacting species also show significantly greater variability in their levels of primary production. Thus, the loss of highly unique, weakly interacting species may eventually lead to dramatic state changes and unpredictable levels of ecosystem functioning. PMID:21106593

SFINX-a drug-drug interaction database designed for clinical decision support systems.

PubMed

Böttiger, Ylva; Laine, Kari; Andersson, Marine L; Korhonen, Tuomas; Molin, Björn; Ovesjö, Marie-Louise; Tirkkonen, Tuire; Rane, Anders; Gustafsson, Lars L; Eiermann, Birgit

2009-06-01

The aim was to develop a drug-drug interaction database (SFINX) to be integrated into decision support systems or to be used in website solutions for clinical evaluation of interactions. Key elements such as substance properties and names, drug formulations, text structures and references were defined before development of the database. Standard operating procedures for literature searches, text writing rules and a classification system for clinical relevance and documentation level were determined. ATC codes, CAS numbers and country-specific codes for substances were identified and quality assured to ensure safe integration of SFINX into other data systems. Much effort was put into giving short and practical advice regarding clinically relevant drug-drug interactions. SFINX includes over 8,000 interaction pairs and is integrated into Swedish and Finnish computerised decision support systems. Over 31,000 physicians and pharmacists are receiving interaction alerts through SFINX. User feedback is collected for continuous improvement of the content. SFINX is a potentially valuable tool delivering instant information on drug interactions during prescribing and dispensing.

Knowledge elicitation for an operator assistant system in process control tasks

NASA Technical Reports Server (NTRS)

Boy, Guy A.

1988-01-01

A knowledge based system (KBS) methodology designed to study human machine interactions and levels of autonomy in allocation of process control tasks is presented. Users are provided with operation manuals to assist them in normal and abnormal situations. Unfortunately, operation manuals usually represent only the functioning logic of the system to be controlled. The user logic is often totally different. A method is focused on which illicits user logic to refine a KBS shell called an Operator Assistant (OA). If the OA is to help the user, it is necessary to know what level of autonomy gives the optimal performance of the overall man-machine system. For example, for diagnoses that must be carried out carefully by both the user and the OA, interactions are frequent, and processing is mostly sequential. Other diagnoses can be automated, in which the case the OA must be able to explain its reasoning in an appropriate level of detail. OA structure was used to design a working KBS called HORSES (Human Orbital Refueling System Expert System). Protocol analysis of pilots interacting with this system reveals that the a-priori analytical knowledge becomes more structured with training and the situation patterns more complex and dynamic. This approach can improve the a-priori understanding of human and automatic reasoning.

Detuning-induced stimulated Raman adiabatic passage in dense two-level systems

NASA Astrophysics Data System (ADS)

Deng, Li; Lin, Gongwei; Niu, Yueping; Gong, Shangqing

2018-05-01

We investigate the coherence generation in dense two-level systems under detuning-induced stimulated Raman adiabatic passage (D-STIRAP). In the dense two-level system, the near dipole-dipole (NDD) interaction should be taken into consideration. With the increase in the strength of the NDD interaction, it is found that a switchlike transition of the generated coherence from maximum value to zero appears. Meanwhile, the adiabatic condition of the D-STIRAP is destroyed in the presence of the NDD interaction. In order to avoid the sudden decrease in the generated coherence and maintain the maximum value, we can use stronger detuning pulse or pump pulse, between which increasing the intensity of the detuning pulse is of more efficiency. Except for taking advantage of such maximum coherence in the high density case into areas like enhancing the four-wave mixing process, we also point out that the phenomenon of the coherence transition can be applied as an optical switch.

Modes of Interaction between Individuals Dominate the Topologies of Real World Networks

PubMed Central

Lee, Insuk; Kim, Eiru; Marcotte, Edward M.

2015-01-01

We find that the topologies of real world networks, such as those formed within human societies, by the Internet, or among cellular proteins, are dominated by the mode of the interactions considered among the individuals. Specifically, a major dichotomy in previously studied networks arises from modeling networks in terms of pairwise versus group tasks. The former often intrinsically give rise to scale-free, disassortative, hierarchical networks, whereas the latter often give rise to single- or broad-scale, assortative, nonhierarchical networks. These dependencies explain contrasting observations among previous topological analyses of real world complex systems. We also observe this trend in systems with natural hierarchies, in which alternate representations of the same networks, but which capture different levels of the hierarchy, manifest these signature topological differences. For example, in both the Internet and cellular proteomes, networks of lower-level system components (routers within domains or proteins within biological processes) are assortative and nonhierarchical, whereas networks of upper-level system components (internet domains or biological processes) are disassortative and hierarchical. Our results demonstrate that network topologies of complex systems must be interpreted in light of their hierarchical natures and interaction types. PMID:25793969

Arctic System Science: Meeting Earth System and Social Impact Challenges through Integrative Approaches and Synthesis

NASA Astrophysics Data System (ADS)

Vorosmarty, C. J.; Hinzman, L. D.; Rawlins, M. A.; Serreze, M. C.; Francis, J. A.; Liljedahl, A. K.; McDonald, K. C.; Piasecki, M.; Rich, R. H.; Holland, M. M.

2017-12-01

The Arctic is an integral part of the Earth system where multiple interactions unite its natural and human elements. Recent observations show the Arctic to be experiencing rapid and amplified signatures of global climate change. At the same time, the Arctic system's response to this broader forcing has itself become a central research topic, given its potential role as a critical throttle on future planetary dynamics. Changes are already impacting life systems and economic prosperity and continued change is expected to bear major implications far outside the region. We also have entered an era when environmental management, traditionally local in scope, must confront regional, whole biome, and pan-Arctic biogeophysical challenges. While challenges may appear to operate in isolation, they emerge within the context of an evolving, integrated Arctic system defined by interactions among natural and social sub-systems. Clearly, new efforts aimed at community planning, industrial development, and infrastructure construction must consider this multiplicity of interacting processes. We recently organized an "Arctic System Synthesis Workshop Series" supported by the Arctic Systems Science Program of NSF and devoted to exploring approaches capable of uncovering the systems-level behavior in both the natural and social sciences domains. The series featured two topical meetings. The first identified the sources responsible for extreme climate events in the Arctic. The second focused on multiple "currencies" within the system (i.e., water, energy, carbon, nutrients) and how they interact to produce systems-level behaviors. More than 40 experts participated, drawn from the ranks of Arctic natural and social sciences. We report here on the workshop series consensus report, which identifies a broad array of topics. Principal among these are a consideration of why study the Arctic as a system, as well as an articulation of the major systems-level approaches to support basic as well as policy-relevant research on the Arctic. Two examples of these approaches are given with respect to extremes (exposure, impacts and reverberations within and outside of the Arctic) and currencies (their role in "uniting" the Arctic as an interacting system). We will also review some proposed programmatic elements to support this new science.

An Overview of Starfish: A Table-Centric Tool for Interactive Synthesis

NASA Technical Reports Server (NTRS)

Tsow, Alex

2008-01-01

Engineering is an interactive process that requires intelligent interaction at many levels. My thesis [1] advances an engineering discipline for high-level synthesis and architectural decomposition that integrates perspicuous representation, designer interaction, and mathematical rigor. Starfish, the software prototype for the design method, implements a table-centric transformation system for reorganizing control-dominated system expressions into high-level architectures. Based on the digital design derivation (DDD) system a designer-guided synthesis technique that applies correctness preserving transformations to synchronous data flow specifications expressed as co- recursive stream equations Starfish enhances user interaction and extends the reachable design space by incorporating four innovations: behavior tables, serialization tables, data refinement, and operator retiming. Behavior tables express systems of co-recursive stream equations as a table of guarded signal updates. Developers and users of the DDD system used manually constructed behavior tables to help them decide which transformations to apply and how to specify them. These design exercises produced several formally constructed hardware implementations: the FM9001 microprocessor, an SECD machine for evaluating LISP, and the SchemEngine, garbage collected machine for interpreting a byte-code representation of compiled Scheme programs. Bose and Tuna, two of DDD s developers, have subsequently commercialized the design derivation methodology at Derivation Systems, Inc. (DSI). DSI has formally derived and validated PCI bus interfaces and a Java byte-code processor; they further executed a contract to prototype SPIDER-NASA's ultra-reliable communications bus. To date, most derivations from DDD and DRS have targeted hardware due to its synchronous design paradigm. However, Starfish expressions are independent of the synchronization mechanism; there is no commitment to hardware or globally broadcast clocks. Though software back-ends for design derivation are limited to the DDD stream-interpreter, targeting synchronous or real-time software is not substantively different from targeting hardware.

Supporting shared decision making beyond consumer-prescriber interactions: Initial development of the CommonGround fidelity scale

PubMed Central

Fukui, Sadaaki; Salyers, Michelle P.; Rapp, Charlie; Goscha, Rick; Young, Leslie; Mabry, Ally

2015-01-01

Shared decision-making has become a central tenet of recovery-oriented, person-centered mental health care, yet the practice is not always transferred to the routine psychiatric visit. Supporting the practice at the system level, beyond the interactions of consumers and medication prescribers, is needed for successful adoption of shared decision-making. CommonGround is a systemic approach, intended to be part of a larger integration of shared decision-making tools and practices at the system level. We discuss the organizational components that CommonGround uses to facilitate shared decision-making, and we present a fidelity scale to assess how well the system is being implemented. PMID:28090194

Concept-Based Grammatical Errors of Arab EFL Learners

ERIC Educational Resources Information Center

Al-Quran, Majed

2010-01-01

Building up messages as a cognitive activity within the linguistic multi-level system is the result of the interaction between the various components of this system. Yet, this interactive process occurring in the language user's mind while encoding can vary from person to person. Likewise, it also differs in different recipients while decoding.…

Level statistics of disordered spin-1/2 systems and materials with localized Cooper pairs.

PubMed

Cuevas, Emilio; Feigel'man, Mikhail; Ioffe, Lev; Mezard, Marc

2012-01-01

The origin of continuous energy spectra in large disordered interacting quantum systems is one of the key unsolved problems in quantum physics. Although small quantum systems with discrete energy levels are noiseless and stay coherent forever in the absence of any coupling to external world, most large-scale quantum systems are able to produce a thermal bath and excitation decay. This intrinsic decoherence is manifested by a broadening of energy levels, which aquire a finite width. The important question is: what is the driving force and the mechanism of transition(s) between these two types of many-body systems - with and without intrinsic decoherence? Here we address this question via the numerical study of energy-level statistics of a system of interacting spin-1/2 with random transverse fields. We present the first evidence for a well-defined quantum phase transition between domains of discrete and continous many-body spectra in such spin models, implying the appearance of novel insulating phases in the vicinity of the superconductor-insulator transition in InO(x) and similar materials.

Spontaneous emergence of cataclysmic networks in spatially extended systems

NASA Astrophysics Data System (ADS)

Manrubia, Susanna C.; Poyatos, Juan F.; Pérez-Mercader, Juan

2002-11-01

A system of interacting chemical species able to catalyse each others' production is studied. We consider a two-dimensional surface where single molecules attach, diffuse, catalytically interact, and decay. The population of species molecules and the network of interactions among them are dynamical entities. After a short transient time, robust catalytic cycles emerge and a "stationary" state of high diversity and large population numbers settles down. Population dynamics and physical space select among possible graphs of catalytic interactions. The organization of the system is robust: parasitic invaders are short-lived, their populations are kept at low levels, and are unable to sweep away the emerging catalytic cycles.

The Influence of the Application of Personal Response Systems on the Effects of Teaching and Learning Physics at the High School Level

ERIC Educational Resources Information Center

Binek, Slawomir; Kimla, Damian; Jarosz, Jerzy

2017-01-01

We report on the effectiveness of using interactive personal response systems in teaching physics in secondary schools. Our research were conducted over the period of 2013-2016 using the system called clickers. The idea is based on a reciprocal interaction allowing one to ask questions and receive immediate responses from all the students…

Modelling the Evolution of Social Structure

PubMed Central

Sutcliffe, A. G.; Dunbar, R. I. M.; Wang, D.

2016-01-01

Although simple social structures are more common in animal societies, some taxa (mainly mammals) have complex, multi-level social systems, in which the levels reflect differential association. We develop a simulation model to explore the conditions under which multi-level social systems of this kind evolve. Our model focuses on the evolutionary trade-offs between foraging and social interaction, and explores the impact of alternative strategies for distributing social interaction, with fitness criteria for wellbeing, alliance formation, risk, stress and access to food resources that reward social strategies differentially. The results suggest that multi-level social structures characterised by a few strong relationships, more medium ties and large numbers of weak ties emerge only in a small part of the overall fitness landscape, namely where there are significant fitness benefits from wellbeing and alliance formation and there are high levels of social interaction. In contrast, ‘favour-the-few’ strategies are more competitive under a wide range of fitness conditions, including those producing homogeneous, single-level societies of the kind found in many birds and mammals. The simulations suggest that the development of complex, multi-level social structures of the kind found in many primates (including humans) depends on a capacity for high investment in social time, preferential social interaction strategies, high mortality risk and/or differential reproduction. These conditions are characteristic of only a few mammalian taxa. PMID:27427758

The Importance of Interactions at the Molecular Level: A Spectroscopic Study of a New Composite Sorber Material.

PubMed

Crocellà, Valentina; Groppo, Elena; Dani, Alessandro; Castellero, Alberto; Bordiga, Silvia; Zilio, Stefano; De Simone, Agnello; Vacca, Paolo

2017-10-01

The functional properties of a new composite material having water vapor getter properties have been investigated by a large arsenal of characterization techniques. The composite system is originated by combining two constituents having very different chemical natures, a magnesium perchlorate (Mg(ClO 4 ) 2 ) salt and a polymeric acrylic matrix. In particular, Fourier transform infrared (FT-IR) and Raman spectroscopy have been fundamental to understand the type of interactions between the salt and the matrix in different hydration conditions. It was found that in the anhydrous composite system the dispersed Mg(ClO 4 ) 2 salt retains its molecular structure, because Mg 2+ cations are still surrounded by their [ClO 4 ] - counter-anions; at the same time, the salt and the polymeric matrix chemically interact each other at the molecular level. These interactions gradually vanish in the presence of water, and disappear in the fully hydrated composite system, where the Mg 2+ cations are completely solvated by the water molecules.

Sexual Interaction in Nonclinical Couples.

ERIC Educational Resources Information Center

Woody, Jane D.; D'Souza, Henry J.

1997-01-01

Reports on the sexual functioning and interaction of 58 nonclinical heterosexual couples as measured by the Sexual Interaction System Scale (SISS). On all five SISS factors, the nonclinical sample scored significantly better than persons in therapy for sexual dysfunction; they also reported satisfactory relationship adjustment and high levels of…

Mapping Control and Affiliation in Teacher-Student Interaction with State Space Grids

ERIC Educational Resources Information Center

Mainhard, M. Tim; Pennings, Helena J. M.; Wubbels, Theo; Brekelmans, Mieke

2012-01-01

This paper explores how State Space Grids (SSG), a dynamic systems research method, can be used to map teacher-student interactions from moment-to-moment and thereby to incorporate temporal aspects of interaction. Interactions in two secondary school classrooms are described in terms of level of interpersonal control and affiliation, and of…

Decay of interspecific avian flock networks along a disturbance gradient in Amazonia.

PubMed

Mokross, Karl; Ryder, Thomas B; Côrtes, Marina Corrêa; Wolfe, Jared D; Stouffer, Philip C

2014-02-07

Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks.

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

Beck, Ashley; Hunt, Kristopher; Bernstein, Hans C.

Interest in microbial communities for bioprocessing has surged in recent years based on the potential to optimize multiple tasks simultaneously and to enhance process productivity and stability. The presence and magnitude of these desirable system properties often result from interactions between functionally distinct community members. The importance of interactions, while appreciated by some disciplines for decades, has gained interest recently due to the development of ‘omics techniques, polymicrobial culturing approaches, and computational methods which has made the systems-level analysis of interacting components more tractable. This review defines and categorizes natural and engineered system components, interactions, and emergent properties, as wellmore » as presents three ecological theories relevant to microbial communities. Case studies are interpreted to illustrate components, interactions, emergent properties and agreement with theoretical concepts. A general foundation is laid to facilitate interpretation of current systems and to aid in future design of microbial systems for the next generation of bioprocesses.« less

Users matter : multi-agent systems model of high performance computing cluster users.

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

North, M. J.; Hood, C. S.; Decision and Information Sciences

2005-01-01

High performance computing clusters have been a critical resource for computational science for over a decade and have more recently become integral to large-scale industrial analysis. Despite their well-specified components, the aggregate behavior of clusters is poorly understood. The difficulties arise from complicated interactions between cluster components during operation. These interactions have been studied by many researchers, some of whom have identified the need for holistic multi-scale modeling that simultaneously includes network level, operating system level, process level, and user level behaviors. Each of these levels presents its own modeling challenges, but the user level is the most complex duemore » to the adaptability of human beings. In this vein, there are several major user modeling goals, namely descriptive modeling, predictive modeling and automated weakness discovery. This study shows how multi-agent techniques were used to simulate a large-scale computing cluster at each of these levels.« less

Human hypocretin and melanin-concentrating hormone levels are linked to emotion and social interaction.

PubMed

Blouin, Ashley M; Fried, Itzhak; Wilson, Charles L; Staba, Richard J; Behnke, Eric J; Lam, Hoa A; Maidment, Nigel T; Karlsson, Karl Æ; Lapierre, Jennifer L; Siegel, Jerome M

2013-01-01

The neurochemical changes underlying human emotions and social behaviour are largely unknown. Here we report on the changes in the levels of two hypothalamic neuropeptides, hypocretin-1 and melanin-concentrating hormone, measured in the human amygdala. We show that hypocretin-1 levels are maximal during positive emotion, social interaction and anger, behaviours that induce cataplexy in human narcoleptics. In contrast, melanin-concentrating hormone levels are minimal during social interaction, but are increased after eating. Both peptides are at minimal levels during periods of postoperative pain despite high levels of arousal. Melanin-concentrating hormone levels increase at sleep onset, consistent with a role in sleep induction, whereas hypocretin-1 levels increase at wake onset, consistent with a role in wake induction. Levels of these two peptides in humans are not simply linked to arousal, but rather to specific emotions and state transitions. Other arousal systems may be similarly emotionally specialized.

Discovering disease-disease associations by fusing systems-level molecular data

PubMed Central

Žitnik, Marinka; Janjić, Vuk; Larminie, Chris; Zupan, Blaž; Pržulj, Nataša

2013-01-01

The advent of genome-scale genetic and genomic studies allows new insight into disease classification. Recently, a shift was made from linking diseases simply based on their shared genes towards systems-level integration of molecular data. Here, we aim to find relationships between diseases based on evidence from fusing all available molecular interaction and ontology data. We propose a multi-level hierarchy of disease classes that significantly overlaps with existing disease classification. In it, we find 14 disease-disease associations currently not present in Disease Ontology and provide evidence for their relationships through comorbidity data and literature curation. Interestingly, even though the number of known human genetic interactions is currently very small, we find they are the most important predictor of a link between diseases. Finally, we show that omission of any one of the included data sources reduces prediction quality, further highlighting the importance in the paradigm shift towards systems-level data fusion. PMID:24232732

Discovering disease-disease associations by fusing systems-level molecular data.

PubMed

Žitnik, Marinka; Janjić, Vuk; Larminie, Chris; Zupan, Blaž; Pržulj, Nataša

2013-11-15

The advent of genome-scale genetic and genomic studies allows new insight into disease classification. Recently, a shift was made from linking diseases simply based on their shared genes towards systems-level integration of molecular data. Here, we aim to find relationships between diseases based on evidence from fusing all available molecular interaction and ontology data. We propose a multi-level hierarchy of disease classes that significantly overlaps with existing disease classification. In it, we find 14 disease-disease associations currently not present in Disease Ontology and provide evidence for their relationships through comorbidity data and literature curation. Interestingly, even though the number of known human genetic interactions is currently very small, we find they are the most important predictor of a link between diseases. Finally, we show that omission of any one of the included data sources reduces prediction quality, further highlighting the importance in the paradigm shift towards systems-level data fusion.

What are the Outstanding Questions in Biosphere-Atmosphere Exchange?

NASA Astrophysics Data System (ADS)

Katul, G.; Finnigan, J.

2002-12-01

Our answer to this question has three parts. At the highest level human population is now so large (and will grow to 10-12 million by 2050 before stabilizing and reversing) and our capacity to influence the biosphere is so profound that we must now treat human, biophysical and geophysical processes as a single interacting system: the Anthroposphere. The Anthroposphere is a complex adaptive system (CAS) in the sense that action of humans individually or in groups (as large as nations) are a response to an environment that includes not just the geosphere and biosphere but the sum of human interactions as well. These actions, in turn, will change this system that provides critical ecosystem services that we are just now realizing are finite and threatened. At present we lack the tools and understanding even to frame key questions about the Anthroposphere although the emerging discipline of Complex System Science is hinting at ways this might be done. At the next level we address the problems posed by cross-scale interactions central to the state and function of the geosphere and biosphere, where processes at the cellular level, (e.g. photosynthesis and respiration), have consequences on the global level and vice-versa through a sequence of non-linear upscale and downscale interactions. Currently there are large gaps in our understanding of this scale cascade that inhibit our ability to parameterize, model and predict phenomena such as the rapid shifts in climate that recent studies of the paleo record have revealed. In short, we need to quantify the risk that our current actions may cause abrupt climate changes that may then feed upon the Anthrosphere. Unless we can reduce the uncertainty with which we describe quantitatively the non-human parts of the Anthroposphere, the injection of models of human interaction, initially tentative, may reduce our predictive ability to unusable levels. Finally we can detail a set of key processes that are themselves critical to geosphere-biosphere functioning but which are poorly understood as yet.

Cell communities and robustness in development.

PubMed

Monk, N A

1997-11-01

The robustness of patterning events in development is a key feature that must be accounted for in proposed models of these events. When considering explicitly cellular systems, robustness can be exhibited at different levels of organization. Consideration of two widespread patterning mechanisms suggests that robustness at the level of cell communities can result from variable development at the level of individual cells; models of these mechanisms show how interactions between participating cells guarantee community-level robustness. Cooperative interactions enhance homogeneity within communities of like cells and the sharpness of boundaries between communities of distinct cells, while competitive interactions amplify small inhomogeneities within communities of initially equivalent cells, resulting in fine-grained patterns of cell specialization.

The interactions of peripheral membrane proteins with biological membranes

DOE PAGES

Johs, Alexander; Whited, A. M.

2015-07-29

The interactions of peripheral proteins with membrane surfaces are critical to many biological processes, including signaling, recognition, membrane trafficking, cell division and cell structure. On a molecular level, peripheral membrane proteins can modulate lipid composition, membrane dynamics and protein-protein interactions. Biochemical and biophysical studies have shown that these interactions are in fact highly complex, dominated by several different types of interactions, and have an interdependent effect on both the protein and membrane. Here we examine three major mechanisms underlying the interactions between peripheral membrane proteins and membranes: electrostatic interactions, hydrophobic interactions, and fatty acid modification of proteins. While experimental approachesmore » continue to provide critical insights into specific interaction mechanisms, emerging bioinformatics resources and tools contribute to a systems-level picture of protein-lipid interactions. Through these recent advances, we begin to understand the pivotal role of protein-lipid interactions underlying complex biological functions at membrane interfaces.« less

In Situ Proximity Ligation Assays Indicate That Hemochromatosis Proteins Hfe and Transferrin Receptor 2 (Tfr2) Do Not Interact

PubMed Central

Rishi, Gautam; Crampton, Emily M.; Wallace, Daniel F.; Subramaniam, V. Nathan

2013-01-01

The hemochromatosis associated proteins HFE and Transferrin Receptor 2 (TFR2) have been shown to be important for the proper regulation of hepcidin. A number of in vitro studies using transient overexpression systems have suggested that an interaction between HFE and TFR2 is required for the regulation of hepcidin. This model of iron sensing which centers upon the requirement for an interaction between HFE and TFR2 has recently been questioned with in vivo studies in mice from our laboratory and others which suggest that Hfe and Tfr2 can regulate hepcidin independently of each other. To re-examine the postulated interaction between Hfe and Tfr2 we developed a novel expression system in which both proteins are stably co-expressed and used the proximity ligation assay to examine the interactions between Hfe, Tfr1 and Tfr2 at a cellular level. We were able to detect the previously described interaction between Hfe and Tfr1, and heterodimers between Tfr1 and Tfr2; however no interaction between Hfe and Tfr2 was observed in our system. The results from this study indicate that Hfe and Tfr2 do not interact with each other when they are stably expressed at similar levels. Furthermore, these results support in vivo studies which suggest that Hfe and Tfr2 can independently regulate hepcidin. PMID:24155934

A Three-Level Analysis of Collaborative Learning in Dual-Interaction Spaces

ERIC Educational Resources Information Center

Lonchamp, Jacques

2009-01-01

CSCL systems which follow the dual-interaction spaces paradigm support the synchronous construction and discussion of shared artifacts by distributed or colocated small groups of learners. The most recent generic dual-interaction space environments, either model based or component based, can be deeply customized by teachers for supporting…

AUTOMATED WATER LEVEL MEASUREMENTS IN SMALL-DIAMETER AQUIFER TUBES

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

PETERSEN SW; EDRINGTON RS; MAHOOD RO

2011-01-14

Groundwater contaminated with hexavalent chromium, strontium-90, and uranium discharges into the Columbia River along approximately 16 km (10 mi) of the shoreline. Various treatment systems have and will continue to be implemented to eliminate the impact of Hanford Site contamination to the river. To optimize the various remediation strategies, it is important to understand interactions between groundwater and the surface water of the Columbia River. An automated system to record water levels in aquifer sampling tubes installed in the hyporheic zone was designed and tested to (1) gain a more complete understanding of groundwater/river water interactions based on gaining andmore » losing conditions ofthe Columbia River, (2) record and interpret data for consistent and defensible groundwater/surface water conceptual models that may be used to better predict subsurface contaminant fate and transport, and (3) evaluate the hydrodynamic influence of extraction wells in an expanded pump-and-treat system to optimize the treatment system. A system to measure water levels in small-diameter aquifer tubes was designed and tested in the laboratory and field. The system was configured to allow manual measurements to periodically calibrate the instrument and to permit aquifer tube sampling without removing the transducer tube. Manual measurements were collected with an e-tape designed and fabricated especially for this test. Results indicate that the transducer system accurately records groundwater levels in aquifer tubes. These data are being used to refine the conceptual and numeric models to better understand interactions in the hyporheic zone of the Columbia River and the adjacent river water and groundwater, and changes in hydrochemistry relative to groundwater flux as river water recharges the aquifer and then drains back out in response to changes in the river level.« less

Solar electric propulsion/instrument/subsystems interaction study

NASA Technical Reports Server (NTRS)

Sellen, J. M., Jr.; Cole, R. K.; Kemp, R. F.; Hall, D. F.; Shelton, H.

1973-01-01

The interactive effects between a solar electric propulsion system and an electrically propelled scientific spacecraft were examined. The operation of the ion thrusters may impact upon the acquisition and interpretation of data by the science payload of the spacecraft. The effluents from the operation of the electric propulsion unit may also impact upon the operation of the various subsystems of the vehicle. Specific interactive effects were isolated where meaningful levels of interaction may occur. The level of impact upon elements of the science payload and other affected subsystems is examined, and avenues for the reduction or elimination of impact are defined.

Sensitivity of measurement-based purification processes to inner interactions

NASA Astrophysics Data System (ADS)

Militello, Benedetto; Napoli, Anna

2018-02-01

The sensitivity of a repeated measurement-based purification scheme to additional undesired couplings is analyzed, focusing on the very simple and archetypical system consisting of two two-level systems interacting with a repeatedly measured one. Several regimes are considered and in the strong coupling limit (i.e., when the coupling constant of the undesired interaction is very large) the occurrence of a quantum Zeno effect is proven to dramatically jeopardize the efficiency of the purification process.

Local thermodynamics and the generalized Gibbs-Duhem equation in systems with long-range interactions.

PubMed

Latella, Ivan; Pérez-Madrid, Agustín

2013-10-01

The local thermodynamics of a system with long-range interactions in d dimensions is studied using the mean-field approximation. Long-range interactions are introduced through pair interaction potentials that decay as a power law in the interparticle distance. We compute the local entropy, Helmholtz free energy, and grand potential per particle in the microcanonical, canonical, and grand canonical ensembles, respectively. From the local entropy per particle we obtain the local equation of state of the system by using the condition of local thermodynamic equilibrium. This local equation of state has the form of the ideal gas equation of state, but with the density depending on the potential characterizing long-range interactions. By volume integration of the relation between the different thermodynamic potentials at the local level, we find the corresponding equation satisfied by the potentials at the global level. It is shown that the potential energy enters as a thermodynamic variable that modifies the global thermodynamic potentials. As a result, we find a generalized Gibbs-Duhem equation that relates the potential energy to the temperature, pressure, and chemical potential. For the marginal case where the power of the decaying interaction potential is equal to the dimension of the space, the usual Gibbs-Duhem equation is recovered. As examples of the application of this equation, we consider spatially uniform interaction potentials and the self-gravitating gas. We also point out a close relationship with the thermodynamics of small systems.

Systems Level Dissection of Anaerobic Methane Cycling: Quantitative Measurements of Single Cell Ecophysiology, Genetic Mechanisms, and Microbial Interactions

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

Orphan, Victoria; Tyson, Gene; Meile, Christof

The global biological CH4 cycle is largely controlled through coordinated and often intimate microbial interactions between archaea and bacteria, the majority of which are still unknown or have been only cursorily identified. Members of the methanotrophic archaea, aka ‘ANME’, are believed to play a major role in the cycling of methane in anoxic environments coupled to sulfate, nitrate, and possibly iron and manganese oxides, frequently forming diverse physical and metabolic partnerships with a range of bacteria. The thermodynamic challenges overcome by the ANME and their bacterial partners and corresponding slow rates of growth are common characteristics in anaerobic ecosystems, and,more » in stark contrast to most cultured microorganisms, this type of energy and resource limited microbial lifestyle is likely the norm in the environment. While we have gained an in-depth systems level understanding of fast-growing, energy-replete microorganisms, comparatively little is known about the dynamics of cell respiration, growth, protein turnover, gene expression, and energy storage in the slow-growing microbial majority. These fundamental properties, combined with the observed metabolic and symbiotic versatility of methanotrophic ANME, make these cooperative microbial systems a relevant (albeit challenging) system to study and for which to develop and optimize culture-independent methodologies, which enable a systems-level understanding of microbial interactions and metabolic networks. We used an integrative systems biology approach to study anaerobic sediment microcosms and methane-oxidizing bioreactors and expanded our understanding of the methanotrophic ANME archaea, their interactions with physically-associated bacteria, ecophysiological characteristics, and underlying genetic basis for cooperative microbial methane-oxidation linked with different terminal electron acceptors. Our approach is inherently multi-disciplinary and multi-scaled, combining transcriptional and proteomic analyses with high resolution microscopy techniques, and stable isotopic and chemical analyses that span community level ‘omics investigations (cm scale) to interspecies consortia (µm scale), to the individual cell and its subcellular components (nm scale). We have organized our methodological approach into three broad categories, RNA-based, Protein-targeted and Geochemical, each encompassing a range of scales, with many techniques and resulting datasets that are highly complementary with one another, and together, offer a unique systems-level perspective of methane-based microbial interactions.« less

Segmentation and additive approach: A reliable technique to study noncovalent interactions of large molecules at the surface of single-wall carbon nanotubes.

PubMed

Torres, Ana M; Scheiner, Steve; Roy, Ajit K; Garay-Tapia, Andrés M; Bustamante, John; Kar, Tapas

2016-08-05

This investigation explores a new protocol, named Segmentation and Additive approach (SAA), to study exohedral noncovalent functionalization of single-walled carbon nanotubes with large molecules, such as polymers and biomolecules, by segmenting the entire system into smaller units to reduce computational cost. A key criterion of the segmentation process is the preservation of the molecular structure responsible for stabilization of the entire system in smaller segments. Noncovalent interaction of linoleic acid (LA, C18 H32 O2 ), a fatty acid, at the surface of a (10,0) zigzag nanotube is considered for test purposes. Three smaller segmented models have been created from the full (10,0)-LA system and interaction energies were calculated for these models and compared with the full system at different levels of theory, namely ωB97XD, LDA. The success of this SAA is confirmed as the sum of the interaction energies is in very good agreement with the total interaction energy. Besides reducing computational cost, another merit of SAA is an estimation of the contributions from different sections of the large system to the total interaction energy which can be studied in-depth using a higher level of theory to estimate several properties of each segment. On the negative side, bulk properties, such as HOMO-LUMO (highest occupied molecular orbital - lowest occupied molecular orbital) gap, of the entire system cannot be estimated by adding results from segment models. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Superradiant phase transitions with three-level systems

NASA Astrophysics Data System (ADS)

Baksic, Alexandre; Nataf, Pierre; Ciuti, Cristiano

2013-02-01

We determine the phase diagram of N identical three-level systems interacting with a single photonic mode in the thermodynamical limit (N→∞) by accounting for the so-called diamagnetic term and the inequalities imposed by the Thomas-Reich-Kuhn (TRK) oscillator strength sum rule. The key role of transitions between excited levels and the occurrence of first-order phase transitions is discussed. We show that, in contrast to two-level systems, in the three-level case the TRK inequalities do not always prevent a superradiant phase transition in the presence of a diamagnetic term.

The Pathway Active Learning Environment: An interactive web-based tool for physics education

NASA Astrophysics Data System (ADS)

Nakamura, Christopher Matthew

The work described here represents an effort to design, construct, and test an interactive online multimedia learning environment that can provide physics instruction to students in their homes. The system was designed with one-on-one human tutoring in mind as the mode of instruction. The system uses an original combination of a video-based tutor that incorporates natural language processing video-centered lessons and additional illustrative multimedia. Our Synthetic Interview (SI) tutor provides pre-recorded video answers from expert physics instructors in response to students' typed natural language questions. Our lessons cover Newton's laws and provide a context for the tutoring interaction to occur, connect physics ideas to real-world behavior of mechanical systems, and allow for quantitative testing of physics. Additional multimedia can be used to supplement the SI tutors' explanations and illustrate the physics of interest. The system is targeted at students of algebra-based and concept-based physics at the college and high school level. The system logs queries to the SI tutor, responses to lesson questions and several other interactions with the system, tagging those interactions with a username and timestamp. We have provided several groups of students with access to our system under several different conditions ranging from the controlled conditions of our interview facility to the naturalistic conditions of use at home. In total nearly two-hundred students have accessed the system. To gain insight into the ways students might use the system and understand the utility of its various components we analyzed qualitative interview data collected with 22 algebra-based physics students who worked with our system in our interview facility. We also performed a descriptive analysis of data from the system's log of user interactions. Finally we explored the use of machine learning to explore the possibility of using automated assessment to augment the interactive capabilities of the system as well as to identify productive and unproductive use patterns. This work establishes a proof-of-concept level demonstration of the feasibility of deploying this type of system. The impact of this work and the possibility of future research efforts are discussed in the context of Internet technologies that are changing rapidly.

Toxin-Antitoxin Systems as Multilevel Interaction Systems

PubMed Central

Goeders, Nathalie; Van Melderen, Laurence

2014-01-01

Toxin-antitoxin (TA) systems are small genetic modules usually composed of a toxin and an antitoxin counteracting the activity of the toxic protein. These systems are widely spread in bacterial and archaeal genomes. TA systems have been assigned many functions, ranging from persistence to DNA stabilization or protection against mobile genetic elements. They are classified in five types, depending on the nature and mode of action of the antitoxin. In type I and III, antitoxins are RNAs that either inhibit the synthesis of the toxin or sequester it. In type II, IV and V, antitoxins are proteins that either sequester, counterbalance toxin activity or inhibit toxin synthesis. In addition to these interactions between the antitoxin and toxin components (RNA-RNA, protein-protein, RNA-protein), TA systems interact with a variety of cellular factors, e.g., toxins target essential cellular components, antitoxins are degraded by RNAses or ATP-dependent proteases. Hence, TA systems have the capacity to interact with each other at different levels. In this review, we will discuss the different interactions in which TA systems are involved and their implications in TA system functions and evolution. PMID:24434905

Initial Drug Dissolution from Amorphous Solid Dispersions Controlled by Polymer Dissolution and Drug-Polymer Interaction.

PubMed

Chen, Yuejie; Wang, Shujing; Wang, Shan; Liu, Chengyu; Su, Ching; Hageman, Michael; Hussain, Munir; Haskell, Roy; Stefanski, Kevin; Qian, Feng

2016-10-01

To identify the key formulation factors controlling the initial drug and polymer dissolution rates from an amorphous solid dispersion (ASD). Ketoconazole (KTZ) ASDs using PVP, PVP-VA, HMPC, or HPMC-AS as polymeric matrix were prepared. For each drug-polymer system, two types of formulations with the same composition were prepared: 1. Spray dried dispersion (SDD) that is homogenous at molecular level, 2. Physical blend of SDD (80% drug loading) and pure polymer (SDD-PB) that is homogenous only at powder level. Flory-Huggins interaction parameters (χ) between KTZ and the four polymers were obtained by Flory-Huggins model fitting. Solution (13)C NMR and FT-IR were conducted to investigate the specific drug-polymer interaction in the solution and solid state, respectively. Intrinsic dissolution of both the drug and the polymer from ASDs were studied using a Higuchi style intrinsic dissolution apparatus. PXRD and confocal Raman microscopy were used to confirm the absence of drug crystallinity on the tablet surface before and after dissolution study. In solid state, KTZ is completely miscible with PVP, PVP-VA, or HPMC-AS, demonstrated by the negative χ values of -0.36, -0.46, -1.68, respectively; while is poorly miscible with HPMC shown by a positive χ value of 0.23. According to solution (13)C NMR and FT-IR studies, KTZ interacts with HPMC-AS strongly through H-bonding and dipole induced interaction; with PVPs and PVP-VA moderately through dipole-induced interactions; and with HPMC weakly without detectable attractive interaction. Furthermore, the "apparent" strength of drug-polymer interaction, measured by the extent of peak shift on NMR or FT-IR spectra, increases with the increasing number of interacting drug-polymer pairs. For ASDs with the presence of considerable drug-polymer interactions, such as KTZ/PVPs, KTZ/PVP-VA, or KTZ /HPMC-AS systems, drug released at the same rate as the polymer when intimate drug-polymer mixing was ensured (i.e., the SDD systems); while drug released much slower than the polymer when molecular level mixing or drug-polymer interaction was absent (SDD-PB systems). For ASDs without drug-polymer interaction (i.e., KTZ/HPMC systems), the mixing homogeneity had little impact on the release rate of either the drug or the polymer thus SDD and SDD-PB demonstrated the same drug or polymer release rate, while the drug released slowly and independently of polymer release. The initial drug release from an ASD was controlled by 1) the polymer release rate; 2) the strength of drug-polymer interaction, including the intrinsic interaction caused by the chemistry of the drug and the polymer (measured by the χ value), as well as that the apparent interaction caused by the drug-polymer ratio (measure by the extent of peak shift on spectroscopic analysis); and 3) the level of mixing homogeneity between the drug and polymer. In summary, the selection of polymer, drug-polymer ratio, and ASD processing conditions have profound impacts on the dissolution behavior of ASDs. Graphical Abstract Relationship between initial drug and polymer dissolution rates from amorphous solid dispersions with different mixing uniformity and drug-polymer interactions.

Control of Stochastic Master Equation Models of Genetic Regulatory Networks by Approximating Their Average Behavior

NASA Astrophysics Data System (ADS)

Umut Caglar, Mehmet; Pal, Ranadip

2010-10-01

The central dogma of molecular biology states that ``information cannot be transferred back from protein to either protein or nucleic acid.'' However, this assumption is not exactly correct in most of the cases. There are a lot of feedback loops and interactions between different levels of systems. These types of interactions are hard to analyze due to the lack of data in the cellular level and probabilistic nature of interactions. Probabilistic models like Stochastic Master Equation (SME) or deterministic models like differential equations (DE) can be used to analyze these types of interactions. SME models based on chemical master equation (CME) can provide detailed representation of genetic regulatory system, but their use is restricted by the large data requirements and computational costs of calculations. The differential equations models on the other hand, have low calculation costs and much more adequate to generate control procedures on the system; but they are not adequate to investigate the probabilistic nature of interactions. In this work the success of the mapping between SME and DE is analyzed, and the success of a control policy generated by DE model with respect to SME model is examined. Index Terms--- Stochastic Master Equation models, Differential Equation Models, Control Policy Design, Systems biology

Modeling joint restoration strategies for interdependent infrastructure systems

PubMed Central

Simonovic, Slobodan P.

2018-01-01

Life in the modern world depends on multiple critical services provided by infrastructure systems which are interdependent at multiple levels. To effectively respond to infrastructure failures, this paper proposes a model for developing optimal joint restoration strategy for interdependent infrastructure systems following a disruptive event. First, models for (i) describing structure of interdependent infrastructure system and (ii) their interaction process, are presented. Both models are considering the failure types, infrastructure operating rules and interdependencies among systems. Second, an optimization model for determining an optimal joint restoration strategy at infrastructure component level by minimizing the economic loss from the infrastructure failures, is proposed. The utility of the model is illustrated using a case study of electric-water systems. Results show that a small number of failed infrastructure components can trigger high level failures in interdependent systems; the optimal joint restoration strategy varies with failure occurrence time. The proposed models can help decision makers to understand the mechanisms of infrastructure interactions and search for optimal joint restoration strategy, which can significantly enhance safety of infrastructure systems. PMID:29649300

Information for Successful Interaction with Autonomous Systems

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Johnson, Kathy A.

2003-01-01

Interaction in heterogeneous mission operations teams is not well matched to classical models of coordination with autonomous systems. We describe methods of loose coordination and information management in mission operations. We describe an information agent and information management tool suite for managing information from many sources, including autonomous agents. We present an integrated model of levels of complexity of agent and human behavior, which shows types of information processing and points of potential error in agent activities. We discuss the types of information needed for diagnosing problems and planning interactions with an autonomous system. We discuss types of coordination for which designs are needed for autonomous system functions.

High-Level Data-Abstraction System

NASA Technical Reports Server (NTRS)

Fishwick, P. A.

1986-01-01

Communication with data-base processor flexible and efficient. High Level Data Abstraction (HILDA) system is three-layer system supporting data-abstraction features of Intel data-base processor (DBP). Purpose of HILDA establishment of flexible method of efficiently communicating with DBP. Power of HILDA lies in its extensibility with regard to syntax and semantic changes. HILDA's high-level query language readily modified. Offers powerful potential to computer sites where DBP attached to DEC VAX-series computer. HILDA system written in Pascal and FORTRAN 77 for interactive execution.

A minimally invasive optical trapping system to understand cellular interactions at onset of an immune response

PubMed Central

Glass, David G.; McAlinden, Niall; Millington, Owain R.

2017-01-01

T-cells and antigen presenting cells are an essential part of the adaptive immune response system and how they interact is crucial in how the body effectively fights infection or responds to vaccines. Much of the experimental work studying interaction forces between cells has looked at the average properties of bulk samples of cells or applied microscopy to image the dynamic contact between these cells. In this paper we present a novel optical trapping technique for interrogating the force of this interaction and measuring relative interaction forces at the single-cell level. A triple-spot optical trap is used to directly manipulate the cells of interest without introducing foreign bodies such as beads to the system. The optical trap is used to directly control the initiation of cell-cell contact and, subsequently to terminate the interaction at a defined time point. The laser beam power required to separate immune cell pairs is determined and correlates with the force applied by the optical trap. As proof of concept, the antigen-specific increase in interaction force between a dendritic cell and a specific T-cell is demonstrated. Furthermore, it is demonstrated that this interaction force is completely abrogated when T-cell signalling is blocked. As a result the potential of using optical trapping to interrogate cellular interactions at the single cell level without the need to introduce foreign bodies such as beads is clearly demonstrated. PMID:29220398

Constraints imposed by pollinator behaviour on the ecology and evolution of plant mating systems.

PubMed

Devaux, C; Lepers, C; Porcher, E

2014-07-01

Most flowering plants rely on pollinators for their reproduction. Plant-pollinator interactions, although mutualistic, involve an inherent conflict of interest between both partners and may constrain plant mating systems at multiple levels: the immediate ecological plant selfing rates, their distribution in and contribution to pollination networks, and their evolution. Here, we review experimental evidence that pollinator behaviour influences plant selfing rates in pairs of interacting species, and that plants can modify pollinator behaviour through plastic and evolutionary changes in floral traits. We also examine how theoretical studies include pollinators, implicitly or explicitly, to investigate the role of their foraging behaviour in plant mating system evolution. In doing so, we call for more evolutionary models combining ecological and genetic factors, and additional experimental data, particularly to describe pollinator foraging behaviour. Finally, we show that recent developments in ecological network theory help clarify the impact of community-level interactions on plant selfing rates and their evolution and suggest new research avenues to expand the study of mating systems of animal-pollinated plant species to the level of the plant-pollinator networks. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Scale-dependent behavior of scale equations.

PubMed

Kim, Pilwon

2009-09-01

We propose a new mathematical framework to formulate scale structures of general systems. Stack equations characterize a system in terms of accumulative scales. Their behavior at each scale level is determined independently without referring to other levels. Most standard geometries in mathematics can be reformulated in such stack equations. By involving interaction between scales, we generalize stack equations into scale equations. Scale equations are capable to accommodate various behaviors at different scale levels into one integrated solution. On contrary to standard geometries, such solutions often reveal eccentric scale-dependent figures, providing a clue to understand multiscale nature of the real world. Especially, it is suggested that the Gaussian noise stems from nonlinear scale interactions.

General and craniofacial development are complex adaptive processes influenced by diversity.

PubMed

Brook, A H; O'Donnell, M Brook; Hone, A; Hart, E; Hughes, T E; Smith, R N; Townsend, G C

2014-06-01

Complex systems are present in such diverse areas as social systems, economies, ecosystems and biology and, therefore, are highly relevant to dental research, education and practice. A Complex Adaptive System in biological development is a dynamic process in which, from interacting components at a lower level, higher level phenomena and structures emerge. Diversity makes substantial contributions to the performance of complex adaptive systems. It enhances the robustness of the process, allowing multiple responses to external stimuli as well as internal changes. From diversity comes variation in outcome and the possibility of major change; outliers in the distribution enhance the tipping points. The development of the dentition is a valuable, accessible model with extensive and reliable databases for investigating the role of complex adaptive systems in craniofacial and general development. The general characteristics of such systems are seen during tooth development: self-organization; bottom-up emergence; multitasking; self-adaptation; variation; tipping points; critical phases; and robustness. Dental findings are compatible with the Random Network Model, the Threshold Model and also with the Scale Free Network Model which has a Power Law distribution. In addition, dental development shows the characteristics of Modularity and Clustering to form Hierarchical Networks. The interactions between the genes (nodes) demonstrate Small World phenomena, Subgraph Motifs and Gene Regulatory Networks. Genetic mechanisms are involved in the creation and evolution of variation during development. The genetic factors interact with epigenetic and environmental factors at the molecular level and form complex networks within the cells. From these interactions emerge the higher level tissues, tooth germs and mineralized teeth. Approaching development in this way allows investigation of why there can be variations in phenotypes from identical genotypes; the phenotype is the outcome of perturbations in the cellular systems and networks, as well as of the genotype. Understanding and applying complexity theory will bring about substantial advances not only in dental research and education but also in the organization and delivery of oral health care. © 2014 Australian Dental Association.

Bivariate- distribution for transition matrix elements in Breit-Wigner to Gaussian domains of interacting particle systems.

PubMed

Kota, V K B; Chavda, N D; Sahu, R

2006-04-01

Interacting many-particle systems with a mean-field one-body part plus a chaos generating random two-body interaction having strength lambda exhibit Poisson to Gaussian orthogonal ensemble and Breit-Wigner (BW) to Gaussian transitions in level fluctuations and strength functions with transition points marked by lambda = lambda c and lambda = lambda F, respectively; lambda F > lambda c. For these systems a theory for the matrix elements of one-body transition operators is available, as valid in the Gaussian domain, with lambda > lambda F, in terms of orbital occupation numbers, level densities, and an integral involving a bivariate Gaussian in the initial and final energies. Here we show that, using a bivariate-t distribution, the theory extends below from the Gaussian regime to the BW regime up to lambda = lambda c. This is well tested in numerical calculations for 6 spinless fermions in 12 single-particle states.

Rydberg interaction induced enhanced excitation in thermal atomic vapor.

PubMed

Kara, Dushmanta; Bhowmick, Arup; Mohapatra, Ashok K

2018-03-27

We present the experimental demonstration of interaction induced enhancement in Rydberg excitation or Rydberg anti-blockade in thermal atomic vapor. We have used optical heterodyne detection technique to measure Rydberg population due to two-photon excitation to the Rydberg state. The anti-blockade peak which doesn't satisfy the two-photon resonant condition is observed along with the usual two-photon resonant peak which can't be explained using the model with non-interacting three-level atomic system. A model involving two interacting atoms is formulated for thermal atomic vapor using the dressed states of three-level atomic system to explain the experimental observations. A non-linear dependence of vapor density is observed for the anti-blockade peak which also increases with increase in principal quantum number of the Rydberg state. A good agreement is found between the experimental observations and the proposed interacting model. Our result implies possible applications towards quantum logic gates using Rydberg anti-blockade in thermal atomic vapor.

Multi-Objective Mission Route Planning Using Particle Swarm Optimization

DTIC Science & Technology

2002-03-01

solutions to complex problems using particles that interact with each other. Both Particle Swarm Optimization (PSO) and the Ant System (AS) have been...EXPERIMENTAL DESING PROCESS..............................................................55 5.1. Introduction...46 18. Phenotype level particle interaction

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

Abanin, D. A.; Department of Physics, Princeton University, Princeton, New Jersey 08544; Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106

Quantum Hall states that result from interaction induced lifting of the eightfold degeneracy of the zeroth Landau level in bilayer graphene are considered. We show that at even filling factors electric charge is injected into the system in the form of charge 2e Skyrmions. This is a rare example of binding of charges in a system with purely repulsive interactions. We calculate the Skyrmion energy and size as a function of the effective Zeeman interaction and discuss the signatures of the charge 2e Skyrmions in the scanning probe experiments.

Assessing the Key to Effective Coaching in Parent-Child Interaction Therapy: The Therapist-Parent Interaction Coding System

PubMed Central

Barnett, Miya L.; Niec, Larissa N.; Acevedo-Polakovich, I. David

2013-01-01

This paper describes the initial evaluation of the Therapist-Parent Interaction Coding System (TPICS), a measure of in vivo therapist coaching for the evidence-based behavioral parent training intervention, parent-child interaction therapy (PCIT). Sixty-one video-recorded treatment sessions were coded with the TPICS to investigate (1) the variety of coaching techniques PCIT therapists use in the early stage of treatment, (2) whether parent skill-level guides a therapist’s coaching style and frequency, and (3) whether coaching mediates changes in parents’ skill levels from one session to the next. Results found that the TPICS captured a range of coaching techniques, and that parent skill-level prior to coaching did relate to therapists’ use of in vivo feedback. Therapists’ responsive coaching (e.g., praise to parents) was a partial mediator of change in parenting behavior from one session to the next for specific child-centered parenting skills; whereas directive coaching (e.g., modeling) did not relate to change. The TPICS demonstrates promise as a measure of coaching during PCIT with good reliability scores and initial evidence of construct validity. PMID:24839350

The interactive systems framework applied to the strategic prevention framework: the Rhode Island experience.

PubMed

Florin, Paul; Friend, Karen B; Buka, Stephen; Egan, Crystelle; Barovier, Linda; Amodei, Brenda

2012-12-01

The Interactive Systems Framework for Dissemination and Implementation (ISF) was introduced as a heuristic systems level model to help bridge the gap between research and practice (Wandersman et al., in Am J Commun Psychol 41:171-181, 2008). This model describes three interacting systems with distinct functions that (1) distill knowledge to develop innovations; (2) provide supportive training and technical assistance for dissemination to; (3) a prevention delivery system responsible for implementation in the field. The Strategic Prevention Framework (SPF) is a major prevention innovation launched by the Center for Substance Abuse Prevention (CSAP) of the Substance Abuse and Mental Health Services Administration (SAMHSA). The SPF offers a structured, sequential, data-driven approach that explicitly targets environmental conditions in the community and aims for change in substance use and problems at the population level. This paper describes how the ISF was applied to the challenges of implementing the SPF in 14 Rhode Island communities, with a focus on the development of a new Training and Technical Assistance Resources Center to support SPF efforts. More specifically, we (1) describe each of the three ISF interacting systems as they evolved in Rhode Island; (2) articulate the lines of communication between the three systems; and (3) examine selected evaluation data to understand relationships between training and technical assistance and SPF implementation and outcomes.

Interaction of biological systems with static and ELF electric and magnetic fields

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

Anderson, L.E.; Kelman, B.J.; Weigel, R.J.

1987-01-01

Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic fieldmore » strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.« less

Abasy Atlas: a comprehensive inventory of systems, global network properties and systems-level elements across bacteria

PubMed Central

Ibarra-Arellano, Miguel A.; Campos-González, Adrián I.; Treviño-Quintanilla, Luis G.; Tauch, Andreas; Freyre-González, Julio A.

2016-01-01

The availability of databases electronically encoding curated regulatory networks and of high-throughput technologies and methods to discover regulatory interactions provides an invaluable source of data to understand the principles underpinning the organization and evolution of these networks responsible for cellular regulation. Nevertheless, data on these sources never goes beyond the regulon level despite the fact that regulatory networks are complex hierarchical-modular structures still challenging our understanding. This brings the necessity for an inventory of systems across a large range of organisms, a key step to rendering feasible comparative systems biology approaches. In this work, we take the first step towards a global understanding of the regulatory networks organization by making a cartography of the functional architectures of diverse bacteria. Abasy (Across-bacteria systems) Atlas provides a comprehensive inventory of annotated functional systems, global network properties and systems-level elements (global regulators, modular genes shaping functional systems, basal machinery genes and intermodular genes) predicted by the natural decomposition approach for reconstructed and meta-curated regulatory networks across a large range of bacteria, including pathogenically and biotechnologically relevant organisms. The meta-curation of regulatory datasets provides the most complete and reliable set of regulatory interactions currently available, which can even be projected into subsets by considering the force or weight of evidence supporting them or the systems that they belong to. Besides, Abasy Atlas provides data enabling large-scale comparative systems biology studies aimed at understanding the common principles and particular lifestyle adaptions of systems across bacteria. Abasy Atlas contains systems and system-level elements for 50 regulatory networks comprising 78 649 regulatory interactions covering 42 bacteria in nine taxa, containing 3708 regulons and 1776 systems. All this brings together a large corpus of data that will surely inspire studies to generate hypothesis regarding the principles governing the evolution and organization of systems and the functional architectures controlling them. Database URL: http://abasy.ccg.unam.mx PMID:27242034

Reducing drug–herb interaction risk with a computerized reminder system

PubMed Central

Lin, Sheng-Shing; Tsai, Chiu-Lin; Tu, Ching-Yeh; Hsieh, Ching-Liang

2015-01-01

Background Traditional Chinese medicine (TCM) and Western medicine are both popular in Taiwan. Approximately 14.1% of Taiwanese residents use Western drugs and Chinese herbs concurrently; therefore, drug–herb interaction is critical to patient safety. This paper presents a new procedure for reducing the risk of drug interactions. Methods Hospital computer systems are modified to ensure that drug–herb interactions are automatically detected when a TCM practitioner is writing a prescription. A pop-up reminder appears, warning of interactions, and the practitioner may adjust doses, delete herbs, or leave the prescription unchanged. A pharmacist will receive interaction information through the system and provide health education to the patient. Results During the 2011–2013 study period, 256 patients received 891 herbal prescriptions with potential drug–herb interactions. Three of the 50 patients who concurrently used ginseng and antidiabetic drugs manifested hypoglycemia (fasting blood sugar level ≤70 mg/dL). Conclusion Drug–herb interactions can cause adverse reactions. A computerized reminder system can enable TCM practitioners to reduce the risk of drug–herb interactions. In addition, health education for patients is crucial in avoiding adverse reaction by the interactions. PMID:25733840

To be at the right place at the right time

PubMed Central

2011-01-01

Aim To analyze the hypothesis of events or neighborhood interactions that is based upon recognizable structures of systems which possess a surface in a four dimensional space - time constellation {x, y, z, t}. To include the theory of hierarchic order of structures and aspects of thermodynamically open systems, especially entropy, structural entropy and entropy flow. Hypothesis Any structure is a space - time constellation that occupies a unique space in its environment. The environment can be a system too, and is assumed to be (nearly) constant. Structures can interact in their environment and create a new structure at a higher order level. Interacting structures that create a surface are called a system. Starting from the bottom, such a system is characterized by its inner structures, its surface function, and its neighborhood. Interaction with a neighboring system is called an event. An event can alter a system, create new systems or induce the decay of a system, dependent upon the surrounding lower level system (background). Results The hypothesis results in a uniform theory about matter, life, diseases, or behavior. Concrete applications permit the estimation of duration of life in man, for example the effect of solid cancer in man, or appearance of protozoans in sexual or asexual reduplication. In addition, it can successfully describe the development of the universe (small exceed of matter above antimatter at the big bang), or the increase of structures (and systems) with increasing time (development of intelligent systems). The three dimensional space possesses the lowest number of mandatory dimensions to implement such a system. PMID:21781323

To be at the right place at the right time.

PubMed

Kayser, Klaus; Borkenfeld, Stephan; Goldmann, Torsten; Kayser, Gian

2011-07-22

To analyze the hypothesis of events or neighborhood interactions that is based upon recognizable structures of systems which possess a surface in a four dimensional space-time constellation {x, y, z, t}. To include the theory of hierarchic order of structures and aspects of thermodynamically open systems, especially entropy, structural entropy and entropy flow. Any structure is a space-time constellation that occupies a unique space in its environment. The environment can be a system too, and is assumed to be (nearly) constant. Structures can interact in their environment and create a new structure at a higher order level. Interacting structures that create a surface are called a system. Starting from the bottom, such a system is characterized by its inner structures, its surface function, and its neighborhood. Interaction with a neighboring system is called an event. An event can alter a system, create new systems or induce the decay of a system, dependent upon the surrounding lower level system (background). The hypothesis results in a uniform theory about matter, life, diseases, or behavior. Concrete applications permit the estimation of duration of life in man, for example the effect of solid cancer in man, or appearance of protozoans in sexual or asexual reduplication. In addition, it can successfully describe the development of the universe (small exceed of matter above antimatter at the big bang), or the increase of structures (and systems) with increasing time (development of intelligent systems). The three dimensional space possesses the lowest number of mandatory dimensions to implement such a system.

Systems biology approach to bioremediation

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

Chakraborty, Romy; Wu, Cindy H.; Hazen, Terry C.

2012-06-01

Bioremediation has historically been approached as a ‘black box’ in terms of our fundamental understanding. Thus it succeeds and fails, seldom without a complete understanding of why. Systems biology is an integrated research approach to study complex biological systems, by investigating interactions and networks at the molecular, cellular, community, and ecosystem level. The knowledge of these interactions within individual components is fundamental to understanding the dynamics of the ecosystem under investigation. Finally, understanding and modeling functional microbial community structure and stress responses in environments at all levels have tremendous implications for our fundamental understanding of hydrobiogeochemical processes and the potentialmore » for making bioremediation breakthroughs and illuminating the ‘black box’.« less

Combined effects of circulating levels of 25-hydroxyvitamin d and Th1 and th2 cytokines on breast cancer estrogen receptor status.

PubMed

Yao, Song; Hong, Chi-Chen; McCann, Susan E; Zirpoli, Gary; Quan, Lei; Gong, Zhihong; Johnson, Candace S; Trump, Donald L; Ambrosone, Christine B

2014-01-27

Vitamin D has been recognized for its immune-modulating properties. We have previously found that levels of 25OHD, and cytokines including IL5, IFNα2, and TNFα, are also associated with estrogen receptor (ER) negative breast cancer in younger women. Thus, we hypothesized that there may be interactions between vitamin D and the immune system in influencing breast cancer ER status, which was tested in 490 women with incident breast cancer. There was no correlation of the levels of 25OHD with any cytokine, and their associations with tumor ER negative status were independent of each other. However, premenopausal women with low 25OHD and high TNFα levels had the highest likelihood of having ER negative cancer (odds ratio [OR] = 7.32, 95% confidence interval [CI] = 2.44-21.98), with evidence of synergy between the two (relative excess risk due to interaction [RERI] = 5.46, p for additive interaction = 0.14, and p for multiplicative interaction = 0.09). There were similar synergistic associations between 25OHD and IL5, and several IFNα2 to Th2 cytokine ratios. This is the first study to provide evidence of interactions between vitamin D and the immune system in relation to breast cancer ER status, which may inform combinational use of vitamin D and anti-inflammatory drugs for cancer prevention and therapy.

Combined Effects of Circulating Levels of 25-Hydroxyvitamin D and Th1 and Th2 Cytokines on Breast Cancer Estrogen Receptor Status

PubMed Central

Yao, Song; Hong, Chi-Chen; McCann, Susan E.; Zirpoli, Gary; Quan, Lei; Gong, Zhihong; Johnson, Candace S.; Trump, Donald L.; Ambrosone, Christine B.

2014-01-01

Vitamin D has been recognized for its immune-modulating properties. We have previously found that levels of 25OHD, and cytokines including IL5, IFNα2, and TNFα, are also associated with estrogen receptor (ER) negative breast cancer in younger women. Thus, we hypothesized that there may be interactions between vitamin D and the immune system in influencing breast cancer ER status, which was tested in 490 women with incident breast cancer. There was no correlation of the levels of 25OHD with any cytokine, and their associations with tumor ER negative status were independent of each other. However, premenopausal women with low 25OHD and high TNFα levels had the highest likelihood of having ER negative cancer (odds ratio [OR] = 7.32, 95% confidence interval [CI] = 2.44−21.98), with evidence of synergy between the two (relative excess risk due to interaction [RERI] = 5.46, p for additive interaction = 0.14, and p for multiplicative interaction = 0.09). There were similar synergistic associations between 25OHD and IL5, and several IFNα2 to Th2 cytokine ratios. This is the first study to provide evidence of interactions between vitamin D and the immune system in relation to breast cancer ER status, which may inform combinational use of vitamin D and anti-inflammatory drugs for cancer prevention and therapy. PMID:24473087

Epistatic Effects of Polymorphisms in Genes from the Renin-Angiotensin, Bradykinin, and Fibrinolytic Systems on Plasma t-PA and PAI-1 Levels

PubMed Central

Asselbergs, Folkert W.; Williams, Scott M.; Hebert, Patricia R.; Coffey, Christopher S.; Hillege, Hans L.; Navis, Gerjan; Vaughan, Douglas E.; van Gilst, Wiek H.; Moore, Jason H.

2007-01-01

Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) directly influence thrombus formation and degradation and thereby risk for arterial thrombosis. Activation of the renin-angiotensin system has been linked to the production of PAI-1 expression via the angiotensin II type 1 receptor (AT1R). In addition, bradykinin can induce the release of t-PA through a B2 receptor mechanism. In the present study, we aimed to investigate the epistatic effects of polymorphisms in genes from the renin-angiotensin, bradykinin and fibrinolytic systems on plasma t-PA and PAI-1 levels in a large population-based sample (n=2,527). We demonstrated a strong significant interaction within genetic variations of the bradykinin B2 gene (p=0.002) and between ACE and bradykinin B2 (p=0.003) polymorphisms on t-PA levels in females. In males, polymorphisms in the bradykinin B2 and AT1R gene showed the most strong effect on t-PA levels (p=0.006). In both females as well as males, the bradykinin B2 gene interacted with AT1R gene on plasma PAI-1 levels (p=0.026 and p=0.039, respectively). In addition, the current study found a borderline significant interaction between PAI 4G5G and ACE I/D on plasma t-PA and PAI-1 levels. These results support the idea that the interplay between the renin-angiotensin, bradykinin, and fibrinolytic systems might play an important role in t-PA and PAI-1 biology. PMID:17207964

Core commands across airway facilities systems.

DOT National Transportation Integrated Search

2003-05-01

This study takes a high-level approach to evaluate computer systems without regard to the specific method of : interaction. This document analyzes the commands that Airway Facilities (AF) use across different systems and : the meanings attributed to ...

Local and System Level Considerations for Plasma-Based Techniques in Hypersonic Flight

NASA Astrophysics Data System (ADS)

Suchomel, Charles; Gaitonde, Datta

2007-01-01

The harsh environment encountered due to hypersonic flight, particularly when air-breathing propulsion devices are utilized, poses daunting challenges to successful maturation of suitable technologies. This has spurred the quest for revolutionary solutions, particularly those exploiting the fact that air under these conditions can become electrically conducting either naturally or through artificial enhancement. Optimized development of such concepts must emphasize not only the detailed physics by which the fluid interacts with the imposed electromagnetic fields, but must also simultaneously identify system level issues integration and efficiencies that provide the greatest leverage. This paper presents some recent advances at both levels. At the system level, an analysis is summarized that incorporates the interdependencies occurring between weight, power and flow field performance improvements. Cruise performance comparisons highlight how one drag reduction device interacts with the vehicle to improve range. Quantified parameter interactions allow specification of system requirements and energy consuming technologies that affect overall flight vehicle performance. Results based on on the fundamental physics are presented by distilling numerous computational studies into a few guiding principles. These highlight the complex non-intuitive relationships between the various fluid and electromagnetic fields, together with thermodynamic considerations. Generally, energy extraction is an efficient process, while the reverse is accompanied by significant dissipative heating and inefficiency. Velocity distortions can be detrimental to plasma operation, but can be exploited to tailor flows through innovative electromagnetic configurations.

Groundwater Levels for Selected Wells in the Chehalis River Basin, Washington

USGS Publications Warehouse

Fasser, E.T.; Julich, R.J.

2010-01-01

Groundwater levels for selected wells in the Chehalis River basin, Washington, are presented on an interactive web-based map to document the spatial distribution of groundwater levels in the study area during late summer 2009. Groundwater level data and well information were collected by the U.S. Geological Survey using standard techniques. The data are stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Unintended consequences of information technologies in health care--an interactive sociotechnical analysis.

PubMed

Harrison, Michael I; Koppel, Ross; Bar-Lev, Shirly

2007-01-01

Many unintended and undesired consequences of Healthcare Information Technologies (HIT) flow from interactions between the HIT and the healthcare organization's sociotechnical system-its workflows, culture, social interactions, and technologies. This paper develops and illustrates a conceptual model of these processes that we call Interactive Sociotechnical Analysis (ISTA). ISTA captures common types of interaction with special emphasis on recursive processes, i.e., feedback loops that alter the newly introduced HIT and promote second-level changes in the social system. ISTA draws on prior studies of unintended consequences, along with research in sociotechnical systems, ergonomics, social informatics, technology-in-practice, and social construction of technology. We present five types of sociotechnical interaction and illustrate each with cases from published research. The ISTA model should further research on emergent and recursive processes in HIT implementation and their unintended consequences. Familiarity with the model can also foster practitioners' awareness of unanticipated consequences that only become evident during HIT implementation.

Association of Informal Clinical Integration of Physicians With Cardiac Surgery Payments.

PubMed

Funk, Russell J; Owen-Smith, Jason; Kaufman, Samuel A; Nallamothu, Brahmajee K; Hollingsworth, John M

2018-05-01

To reduce inefficiency and waste associated with care fragmentation, many current programs target greater clinical integration among physicians. However, these programs have led to only modest Medicare spending reductions. Most programs focus on formal integration, which often bears little resemblance to actual physician interaction patterns. To examine how physician interaction patterns vary between health systems and to assess whether variation in informal integration is associated with care delivery payments. National Medicare data from January 1, 2008, through December 31, 2011, identified 253 545 Medicare beneficiaries (aged ≥66 years) from 1186 health systems where Medicare beneficiaries underwent coronary artery bypass grafting (CABG) procedures. Interactions were mapped between all physicians who treated these patients-including primary care physicians and surgical and medical specialists-within a health system during their surgical episode. The level of informal integration was measured in these networks of interacting physicians. Multivariate regression models were fitted to evaluate associations between payments for each surgical episode made on a beneficiary's behalf and the level of informal integration in the health system where the patient was treated. The informal integration level of a health system. Price-standardized total surgical episode and component payments. The total 253 545 study participants included 175 520 men (69.2%; mean [SD] age, 74.51 [5.75] years) and 78 024 women (34.3%; 75.67 [5.91] years). One beneficiary of the 253 545 participants did not have sex information. The low level of informal clinical integration included 84 598 patients (33.4%; mean [SD] age, 75.00 [5.93] years); medium level, 84 442 (33.30%; 74.94 [5.87] years); and high level, 84 505 (33.34%; 74.66 [5.72] years) (P < .001). Informal integration levels varied across health systems. After adjusting for patient, health-system, and community factors, higher levels of informal integration were associated with significantly lower total episode and component payments (β coefficients for informal integration were -365.87 [95% CI, -451.08 to -280.67] for total episode payments, -182.63 [-239.80 to -125.46] for index hospitalization, -43.13 [-55.53 to -30.72] for physician services, -74.48 [-103.45 to -45.51] for hospital readmissions, and -62.04 [-88.00 to -36.07] for postacute care; P < .001 for each association). When beneficiaries were treated in health systems with higher informal integration, the greatest savings of lower estimated payments were from hospital readmissions (13.0%) and postacute care services (5.8%). Informal integration is associated with lower spending. Although most programs that seek to promote clinical integration are focused on health systems' formal structures, policy makers may also want to address informal integration.

Multilevel adaptive control of nonlinear interconnected systems.

PubMed

Motallebzadeh, Farzaneh; Ozgoli, Sadjaad; Momeni, Hamid Reza

2015-01-01

This paper presents an adaptive backstepping-based multilevel approach for the first time to control nonlinear interconnected systems with unknown parameters. The system consists of a nonlinear controller at the first level to neutralize the interaction terms, and some adaptive controllers at the second level, in which the gains are optimally tuned using genetic algorithm. The presented scheme can be used in systems with strong couplings where completely ignoring the interactions leads to problems in performance or stability. In order to test the suitability of the method, two case studies are provided: the uncertain double and triple coupled inverted pendulums connected by springs with unknown parameters. The simulation results show that the method is capable of controlling the system effectively, in both regulation and tracking tasks. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Interactions of sugar-based bolaamphiphiles with biomimetic systems of plasma membranes.

PubMed

Nasir, Mehmet Nail; Crowet, Jean-Marc; Lins, Laurence; Obounou Akong, Firmin; Haudrechy, Arnaud; Bouquillon, Sandrine; Deleu, Magali

2016-11-01

Glycolipids constitute a class of molecules with various biological activities. Among them, sugar-based bolaamphiphiles characterized by their biocompatibility, biodegradability and lower toxicity, became interesting for the development of efficient and low cost lipid-based drug delivery systems. Their activity seems to be closely related to their interactions with the lipid components of the plasma membrane of target cells. Despite many works devoted to the chemical synthesis and characterization of sugar-based bolaamphiphiles, their interactions with plasma membrane have not been completely elucidated. In this work, two sugar-based bolaamphiphiles differing only at the level of their sugar residues were chemically synthetized. Their interactions with membranes have been investigated using model membranes containing or not sterol and with in silico approaches. Our findings indicate that the nature of sugar residues has no significant influence for their membrane interacting properties, while the presence of sterol attenuates the interactions of both bolaamphiphiles with the membrane systems. The understanding of this distinct behavior of bolaamphiphiles towards sterol-containing membrane systems could be useful for their applications as drug delivery systems. Copyright © 2016. Published by Elsevier B.V.

Systems Epidemiology: What’s in a Name?

PubMed Central

Dammann, O.; Gray, P.; Gressens, P.; Wolkenhauer, O.; Leviton, A.

2014-01-01

Systems biology is an interdisciplinary effort to integrate molecular, cellular, tissue, organ, and organism levels of function into computational models that facilitate the identification of general principles. Systems medicine adds a disease focus. Systems epidemiology adds yet another level consisting of antecedents that might contribute to the disease process in populations. In etiologic and prevention research, systems-type thinking about multiple levels of causation will allow epidemiologists to identify contributors to disease at multiple levels as well as their interactions. In public health, systems epidemiology will contribute to the improvement of syndromic surveillance methods. We encourage the creation of computational simulation models that integrate information about disease etiology, pathogenetic data, and the expertise of investigators from different disciplines. PMID:25598870

Hierarchical cortical transcriptome disorganization in autism.

PubMed

Lombardo, Michael V; Courchesne, Eric; Lewis, Nathan E; Pramparo, Tiziano

2017-01-01

Autism spectrum disorders (ASD) are etiologically heterogeneous and complex. Functional genomics work has begun to identify a diverse array of dysregulated transcriptomic programs (e.g., synaptic, immune, cell cycle, DNA damage, WNT signaling, cortical patterning and differentiation) potentially involved in ASD brain abnormalities during childhood and adulthood. However, it remains unclear whether such diverse dysregulated pathways are independent of each other or instead reflect coordinated hierarchical systems-level pathology. Two ASD cortical transcriptome datasets were re-analyzed using consensus weighted gene co-expression network analysis (WGCNA) to identify common co-expression modules across datasets. Linear mixed-effect models and Bayesian replication statistics were used to identify replicable differentially expressed modules. Eigengene network analysis was then utilized to identify between-group differences in how co-expression modules interact and cluster into hierarchical meta-modular organization. Protein-protein interaction analyses were also used to determine whether dysregulated co-expression modules show enhanced interactions. We find replicable evidence for 10 gene co-expression modules that are differentially expressed in ASD cortex. Rather than being independent non-interacting sources of pathology, these dysregulated co-expression modules work in synergy and physically interact at the protein level. These systems-level transcriptional signals are characterized by downregulation of synaptic processes coordinated with upregulation of immune/inflammation, response to other organism, catabolism, viral processes, translation, protein targeting and localization, cell proliferation, and vasculature development. Hierarchical organization of meta-modules (clusters of highly correlated modules) is also highly affected in ASD. These findings highlight that dysregulation of the ASD cortical transcriptome is characterized by the dysregulation of multiple coordinated transcriptional programs producing synergistic systems-level effects that cannot be fully appreciated by studying the individual component biological processes in isolation.

Is there a link between the hospital-acquired injurious fall rates in US acute care hospitals and these institutions' implementation levels of computerized systems?

PubMed

Tzeng, Huey-Ming; Hu, Hsou Mei; Yin, Chang-Yi

2011-12-01

Medicare no longer reimburses acute care hospitals for the costs of additional care required due to hospital-acquired injuries. Consequently, this study explored the effective computerized systems to inform practice for better interventions to reduce fall risk. It provided a correlation between type of computerized system and hospital-acquired injurious fall rates at acute care hospitals in California, Florida, and New York. It used multiple publicly available data sets, with the hospital as the unit of analysis. Descriptive and Pearson correlation analyses were used. The analysis included 462 hospitals. Significant correlations could be categorized into two groups: (1) meaningful computerized systems that were associated with lower injurious fall rates: the decision support systems for drug allergy alerts, drug-drug interaction alerts, and drug-laboratory interaction alerts; and (2) computerized systems that were associated with higher injurious fall rates: the decision support system for drug-drug interaction alerts and the computerized provider order entry system for radiology tests. Future research may include additional states, multiple years of data, and patient-level data to validate this study's findings. This effort may further inform policy makers and the public about effective clinical computerized systems provided to clinicians to improve their practice decisions and care outcomes.

From Additivity to Cooperativity in Chemistry: Can Cooperativity Be Measured?

PubMed

Tebben, Ludger; Mück-Lichtenfeld, Christian; Fernández, Gustavo; Grimme, Stefan; Studer, Armido

2017-05-02

Cooperative effects can be observed in various research areas in chemistry; cooperative catalysis is well-established, the assembly of compounds on surfaces can be steered by cooperative effects, and supramolecular polymerization can proceed in a cooperative manner. In biological systems, cooperativity is observed in protein-protein, protein-lipid and protein-molecule interactions. Synergistic effects are relevant in frustrated Lewis pairs, organic multispin systems, multimetallic clusters and also in nanoparticles. However, a general approach to determine cooperativity in the different chemical systems is currently not known. In the present concept paper it is suggested that, at least for simpler systems that can be described at the molecular level, cooperativity can be defined based on energy considerations. For systems in which no chemical transformation occurs, determination of interaction energies of the whole system with respect to the interaction energies between all individual component pairs (subsystems) will allow determination of cooperativity. For systems comprising of chemical transformations, cooperativity can be evaluated by determining the activation energy of the synergistic system and by comparing this with activation energies of the corresponding subsystems that lack an activating moiety. For more complex systems, cooperativity is generally determined at a qualitative level. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterizing the interaction of groundwater and surface water in the karst aquifer of Fangshan, Beijing (China)

NASA Astrophysics Data System (ADS)

Chu, Haibo; Wei, Jiahua; Wang, Rong; Xin, Baodong

2017-03-01

Correct understanding of groundwater/surface-water (GW-SW) interaction in karst systems is of greatest importance for managing the water resources. A typical karst region, Fangshan in northern China, was selected as a case study. Groundwater levels and hydrochemistry analyses, together with isotope data based on hydrogeological field investigations, were used to assess the GW-SW interaction. Chemistry data reveal that water type and the concentration of cations in the groundwater are consistent with those of the surface water. Stable isotope ratios of all samples are close to the local meteoric water line, and the 3H concentrations of surface water and groundwater samples are close to that of rainfall, so isotopes also confirm that karst groundwater is recharged by rainfall. Cross-correlation analysis reveals that rainfall leads to a rise in groundwater level with a lag time of 2 months and groundwater exploitation leads to a fall within 1 month. Spectral analysis also reveals that groundwater level, groundwater exploitation and rainfall have significantly similar response periods, indicating their possible inter-relationship. Furthermore, a multiple nonlinear regression model indicates that groundwater level can be negatively correlated with groundwater exploitation, and positively correlated with rainfall. The overall results revealed that groundwater level has a close correlation with groundwater exploitation and rainfall, and they are indicative of a close hydraulic connection and interaction between surface water and groundwater in this karst system.

YASS: A System Simulator for Operating System and Computer Architecture Teaching and Learning

ERIC Educational Resources Information Center

Mustafa, Besim

2013-01-01

A highly interactive, integrated and multi-level simulator has been developed specifically to support both the teachers and the learners of modern computer technologies at undergraduate level. The simulator provides a highly visual and user configurable environment with many pedagogical features aimed at facilitating deep understanding of concepts…

Experiments in cooperative manipulation: A system perspective

NASA Technical Reports Server (NTRS)

Schneider, Stanley A.; Cannon, Robert H., Jr.

1989-01-01

In addition to cooperative dynamic control, the system incorporates real time vision feedback, a novel programming technique, and a graphical high level user interface. By focusing on the vertical integration problem, not only these subsystems are examined, but also their interfaces and interactions. The control system implements a multi-level hierarchical structure; the techniques developed for operator input, strategic command, and cooperative dynamic control are presented. At the highest level, a mouse-based graphical user interface allows an operator to direct the activities of the system. Strategic command is provided by a table-driven finite state machine; this methodology provides a powerful yet flexible technique for managing the concurrent system interactions. The dynamic controller implements object impedance control; an extension of Nevill Hogan's impedance control concept to cooperative arm manipulation of a single object. Experimental results are presented, showing the system locating and identifying a moving object catching it, and performing a simple cooperative assembly. Results from dynamic control experiments are also presented, showing the controller's excellent dynamic trajectory tracking performance, while also permitting control of environmental contact force.

Neuroimmune Interactions: From the Brain to the Immune System and Vice Versa.

PubMed

Dantzer, Robert

2018-01-01

Because of the compartmentalization of disciplines that shaped the academic landscape of biology and biomedical sciences in the past, physiological systems have long been studied in isolation from each other. This has particularly been the case for the immune system. As a consequence of its ties with pathology and microbiology, immunology as a discipline has largely grown independently of physiology. Accordingly, it has taken a long time for immunologists to accept the concept that the immune system is not self-regulated but functions in close association with the nervous system. These associations are present at different levels of organization. At the local level, there is clear evidence for the production and use of immune factors by the central nervous system and for the production and use of neuroendocrine mediators by the immune system. Short-range interactions between immune cells and peripheral nerve endings innervating immune organs allow the immune system to recruit local neuronal elements for fine tuning of the immune response. Reciprocally, immune cells and mediators play a regulatory role in the nervous system and participate in the elimination and plasticity of synapses during development as well as in synaptic plasticity at adulthood. At the whole organism level, long-range interactions between immune cells and the central nervous system allow the immune system to engage the rest of the body in the fight against infection from pathogenic microorganisms and permit the nervous system to regulate immune functioning. Alterations in communication pathways between the immune system and the nervous system can account for many pathological conditions that were initially attributed to strict organ dysfunction. This applies in particular to psychiatric disorders and several immune-mediated diseases. This review will show how our understanding of this balance between long-range and short-range interactions between the immune system and the central nervous system has evolved over time, since the first demonstrations of immune influences on brain functions. The necessary complementarity of these two modes of communication will then be discussed. Finally, a few examples will illustrate how dysfunction in these communication pathways results in what was formerly considered in psychiatry and immunology to be strict organ pathologies.

Structure Prediction of Protein Complexes

NASA Astrophysics Data System (ADS)

Pierce, Brian; Weng, Zhiping

Protein-protein interactions are critical for biological function. They directly and indirectly influence the biological systems of which they are a part. Antibodies bind with antigens to detect and stop viruses and other infectious agents. Cell signaling is performed in many cases through the interactions between proteins. Many diseases involve protein-protein interactions on some level, including cancer and prion diseases.

Levels of behavioral organization and the evolution of division of labor

NASA Astrophysics Data System (ADS)

Page, Robert E.; Erber, Joachim

2002-03-01

The major features of insect societies that fascinate biologists are the self-sacrificing altruism expressed by colony members, the complex division of labor, and the tremendous plasticity demonstrated in the face of changing environments. The social behavior of insects is a result of complex interactions at different levels of biological organization. Genes give rise to proteins and peptides that build the nervous and muscular systems, regulate their own synthesis, interact with each other, and affect the behavior of individuals. Social behavior emerges from the complex interactions of individuals that are themselves far removed from the direct effects of the genes. In order to understand how social organization evolves, we must understand the mechanisms that link the different levels of organization. In this review, we discuss how behavior is influenced by genes and the neural system and how social behavior emerges from the behavioral activities of individuals. We show how different levels of organization share common features and are linked through common mechanisms. We focus on the behavior of the honey bee, the best studied of all social insects.

Intelligent Control Systems Research

NASA Technical Reports Server (NTRS)

Loparo, Kenneth A.

1994-01-01

Results of a three phase research program into intelligent control systems are presented. The first phase looked at implementing the lowest or direct level of a hierarchical control scheme using a reinforcement learning approach assuming no a priori information about the system under control. The second phase involved the design of an adaptive/optimizing level of the hierarchy and its interaction with the direct control level. The third and final phase of the research was aimed at combining the results of the previous phases with some a priori information about the controlled system.

The 2ν6/ν2 + ν3/ν3 + ν5 band system of CH3Br revisited: Modeling anharmonic and Coriolis interactions in a three-level system near 2000 cm-1

NASA Astrophysics Data System (ADS)

Ceausu-Velcescu, Adina; Kwabia Tchana, Fridolin; Landsheere, Xavier

2018-06-01

The 2ν6 (A1 + E)/ν2 + ν3 (A1)/ν3 + ν5 (E) band system of CH3Br, near 2000 cm-1, has been studied, for both 79Br and 81Br isotopologues, using Fourier transform infrared spectroscopy, with a resolution of 0.003 cm-1. This band system, revealing anharmonic (Δk = Δl = 0) and Coriolis (Δk = Δl = ± 1) interactions, has been analyzed through a least-squares fit of more than 3000 transitions, for each isotopologue. More than 600 transitions belonging to the very weak ν3 + ν5 combination band were assigned for the first time, for both CH379Br and CH381Br isotopologues. Assignments of the weak 2 ν60 parallel band, which is Fermi-interacting with ν2 + ν3, were also considerably extended with respect to a previous high-resolution study (Najib et al., 1985), thanks to a more accurate knowledge of the Fermi coupling parameters and of the relative positions of the interacting levels. The least-squares fits provided quantitative reproduction of all data belonging to the four above mentioned bands. Moreover, the Coriolis coupling parameters obtained for the ν2 + ν3/ν3 + ν5 interacting bands show a remarkable consistency with those obtained for the ν2/ν5 'fundamental' system (Kwabia Tchana et al., 2004).

Contaminant-State Broadening Mechanism in a Driven Dissipative Rydberg System

NASA Astrophysics Data System (ADS)

Porto, J. V.

2017-04-01

The strong interactions in Rydberg atoms make them an ideal system for the study of correlated many-body physics, both in the presence and absence of dissipation. Using such highly excited atomic states requires addressing challenges posed by the dense spectrum of Rydberg levels, the detrimental effects of spontaneous emission, and strong interactions. A full understanding of the scope and limitations of many Rydberg-based proposals requires simultaneously including these effects, which typically cannot be described by a mean-field treatment due to correlations in the quantum coherent and dissipative processes. We study a driven, dissipative system of Rydberg atoms in a 3D optical lattice, and observe substantial deviation from single-particle excitation rates, both on and off resonance. The observed broadened spectra cannot be explained by van der Waals interactions or a mean-field treatment of the system. Based on the magnitude of the broadening and the scaling with density and two-photon Rabi frequency, we attribute these effects to unavoidable blackbody-induced transitions to nearby Rydberg states of opposite parity, which have large, resonant dipole-dipole interactions with the state of interest. Even at low densities of Rydberg atoms, uncontrolled production of atoms in other states significantly modifies the energy levels of the remaining atoms. These off-diagonal exchange interactions result in complex many-body states of the system and have implications for off-resonant Rydberg dressing proposals. This work was partially supported by the ARL-CDQI program.

Revealing physical interaction networks from statistics of collective dynamics

PubMed Central

Nitzan, Mor; Casadiego, Jose; Timme, Marc

2017-01-01

Revealing physical interactions in complex systems from observed collective dynamics constitutes a fundamental inverse problem in science. Current reconstruction methods require access to a system’s model or dynamical data at a level of detail often not available. We exploit changes in invariant measures, in particular distributions of sampled states of the system in response to driving signals, and use compressed sensing to reveal physical interaction networks. Dynamical observations following driving suffice to infer physical connectivity even if they are temporally disordered, are acquired at large sampling intervals, and stem from different experiments. Testing various nonlinear dynamic processes emerging on artificial and real network topologies indicates high reconstruction quality for existence as well as type of interactions. These results advance our ability to reveal physical interaction networks in complex synthetic and natural systems. PMID:28246630

TRICCS: A proposed teleoperator/robot integrated command and control system for space applications

NASA Technical Reports Server (NTRS)

Will, R. W.

1985-01-01

Robotic systems will play an increasingly important role in space operations. An integrated command and control system based on the requirements of space-related applications and incorporating features necessary for the evolution of advanced goal-directed robotic systems is described. These features include: interaction with a world model or domain knowledge base, sensor feedback, multiple-arm capability and concurrent operations. The system makes maximum use of manual interaction at all levels for debug, monitoring, and operational reliability. It is shown that the robotic command and control system may most advantageously be implemented as packages and tasks in Ada.

Do early sensory cortices integrate cross-modal information?

PubMed

Kayser, Christoph; Logothetis, Nikos K

2007-09-01

Our different senses provide complementary evidence about the environment and their interaction often aids behavioral performance or alters the quality of the sensory percept. A traditional view defers the merging of sensory information to higher association cortices, and posits that a large part of the brain can be reduced into a collection of unisensory systems that can be studied in isolation. Recent studies, however, challenge this view and suggest that cross-modal interactions can already occur in areas hitherto regarded as unisensory. We review results from functional imaging and electrophysiology exemplifying cross-modal interactions that occur early during the evoked response, and at the earliest stages of sensory cortical processing. Although anatomical studies revealed several potential origins of these cross-modal influences, there is yet no clear relation between particular functional observations and specific anatomical connections. In addition, our view on sensory integration at the neuronal level is coined by many studies on subcortical model systems of sensory integration; yet, the patterns of cross-modal interaction in cortex deviate from these model systems in several ways. Consequently, future studies on cortical sensory integration need to leave the descriptive level and need to incorporate cross-modal influences into models of the organization of sensory processing. Only then will we be able to determine whether early cross-modal interactions truly merit the label sensory integration, and how they increase a sensory system's ability to scrutinize its environment and finally aid behavior.

Monoacylglycerol lipase (MGLL) polymorphism rs604300 interacts with childhood adversity to predict cannabis dependence symptoms and amygdala habituation: Evidence from an endocannabinoid system-level analysis

PubMed Central

Carey, Caitlin E.; Agrawal, Arpana; Zhang, Bo; Conley, Emily D.; Degenhardt, Louisa; Heath, Andrew C.; Li, Daofeng; Lynskey, Michael T.; Martin, Nicholas G.; Montgomery, Grant W.; Wang, Ting; Bierut, Laura J.; Hariri, Ahmad R.; Nelson, Elliot C.; Bogdan, Ryan

2015-01-01

Despite evidence for heritable variation in cannabis involvement and the discovery of cannabinoid receptors and their endogenous ligands, no consistent patterns have emerged from candidate endocannabinoid (eCB) genetic association studies of cannabis involvement. Given interactions between eCB and stress systems and associations between childhood stress and cannabis involvement, it may be important to consider childhood adversity in the context of eCB-related genetic variation. We employed a system-level gene-based analysis of data from the Comorbidity and Trauma Study (N = 1,558) to examine whether genetic variation in 6 eCB genes (anabolism: DAGLA, DAGLB, NAPEPLD, catabolism: MGLL, FAAH, binding: CNR1; SNPs N = 65) and childhood sexual abuse (CSA) predicts cannabis dependence symptoms. Significant interactions with CSA emerged for MGLL at the gene-level (p = .009), and for rs604300 within MGLL (ΔR2 = .007, p < .001), the latter of which survived SNP-level Bonferroni correction and was significant in an additional sample with similar directional effects (N = 859; ΔR2 = .005, p = .026). Furthermore, in a third sample (N = 312), there was evidence that rs604300 genotype interacts with early life adversity to predict threat-related basolateral amygdala habituation, a neural phenotype linked to the eCB system and addiction (ΔR2 = .013, p = .047). Rs604300 may be related to epigenetic modulation of MGLL expression. These results are consistent with rodent models implicating 2-arachidonoylglycerol (2-AG), an endogenous cannabinoid metabolized by the enzyme encoded by MGLL, in the etiology of stress adaptation related to cannabis dependence, but require further replication. PMID:26595473

Vehicle-Level Reasoning Systems: Integrating System-Wide Data to Estimate the Instantaneous Health State

NASA Technical Reports Server (NTRS)

Srivastava, Ashok N.; Mylaraswmay, Dinkar; Mah, Robert W.; Cooper, Eric G.

2011-01-01

At the aircraft level, a Vehicle-Level Reasoning System (VLRS) can be developed to provide aircraft with at least two significant capabilities: improvement of aircraft safety due to enhanced monitoring and reasoning about the aircrafts health state, and also potential cost savings by enabling Condition Based Maintenance (CBM). Along with the benefits of CBM, an important challenge facing aviation safety today is safeguarding against system and component failures and malfunctions. Faults can arise in one or more aircraft subsystem their effects in one system may propagate to other subsystems, and faults may interact.

ORNL Direct Purchase Information System (DPIS) user's manual. [For PDP-10

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

Grubb, J.W.; Lovin, J.K.; Smith, M.B.

1980-08-01

The ORNL Management Information System (MIS) Direct Purchase Information System (DPIS) is an on-line interactive system of computer programs. The system can provide a manager with commitment and delivery schedule information on current direct purchase requisitions. The commitment data accounts for the orders that have been placed and those requisitions yet to be placed with a vendor. Information can be summarized at many different levels, and individuals can quickly determine the status of their requisitions. DPIS contains data only on active outside direct purchases, but has the capability to access historical data. It provides sufficient flexibility to be used tomore » answer many questions pertinent to the status of these direct purchases and their obligating costs. Even an inexperienced computer user should have little difficulty in learning to use DPIS. The User Module prompts the user on what type of response it is expecting. If the user has doubts as to the response, or if the meaning of the response is not clear, the module will give a detailed list of the options available at that level. The user has control of what data are to be considered, how they are to be grouped, and what format the output will take. As the user selects the options available at a given level, the module proceeds to the next lower level until sufficient input has been supplied to provide the requested information. A major benefit of this interactive, user-oriented system is that the manager can specify the information requirements and does not have to spend time going through a great deal of other data to locate what is needed. Because it is interactive, a search can begin at a summary level and then resort to a more detailed level if needed. DPIS allows the user direct control for selecting the type of commitment data, output, funds, and direct purchase.« less

Andreev spectrum with high spin-orbit interactions: Revealing spin splitting and topologically protected crossings

NASA Astrophysics Data System (ADS)

Murani, A.; Chepelianskii, A.; Guéron, S.; Bouchiat, H.

2017-10-01

In order to point out experimentally accessible signatures of spin-orbit interaction, we investigate numerically the Andreev spectrum of a multichannel mesoscopic quantum wire (N) with high spin-orbit interaction coupled to superconducting electrodes (S), contrasting topological and nontopological behaviors. In the nontopological case (square lattice with Rashba interactions), we find that the Kramers degeneracy of Andreev levels is lifted by a phase difference between the S reservoirs except at multiples of π , when the normal quantum wires can host several conduction channels. The level crossings at these points invariant by time-reversal symmetry are not lifted by disorder. Whereas the dc Josephson current is insensitive to these level crossings, the high-frequency admittance (susceptibility) at finite temperature reveals these level crossings and the lifting of their degeneracy at π by a small Zeeman field. We have also investigated the hexagonal lattice with intrinsic spin-orbit interaction in the range of parameters where it is a two-dimensional topological insulator with one-dimensional helical edges protected against disorder. Nontopological superconducting contacts can induce topological superconductivity in this system characterized by zero-energy level crossing of Andreev levels. Both Josephson current and finite-frequency admittance carry then very specific signatures at low temperature of this disorder-protected Andreev level crossing at π and zero energy.

Load converter interactions with the secondary system in the Space Station Freedom power management and distribution DC test bed

NASA Technical Reports Server (NTRS)

Lebron, Ramon C.

1992-01-01

The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF Program design and development phases, a system Power Management and Distribution (PMAD) DC test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

Load converter interactions with the secondary system in the Space Station Freedom power management and distribution dc test bed

NASA Technical Reports Server (NTRS)

Lebron, Ramon C.

1992-01-01

The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF program design and development phases, a system Power Management and Distribution (PMAD) dc test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

System-level insights into the cellular interactome of a non-model organism: inferring, modelling and analysing functional gene network of soybean (Glycine max).

PubMed

Xu, Yungang; Guo, Maozu; Zou, Quan; Liu, Xiaoyan; Wang, Chunyu; Liu, Yang

2014-01-01

Cellular interactome, in which genes and/or their products interact on several levels, forming transcriptional regulatory-, protein interaction-, metabolic-, signal transduction networks, etc., has attracted decades of research focuses. However, such a specific type of network alone can hardly explain the various interactive activities among genes. These networks characterize different interaction relationships, implying their unique intrinsic properties and defects, and covering different slices of biological information. Functional gene network (FGN), a consolidated interaction network that models fuzzy and more generalized notion of gene-gene relations, have been proposed to combine heterogeneous networks with the goal of identifying functional modules supported by multiple interaction types. There are yet no successful precedents of FGNs on sparsely studied non-model organisms, such as soybean (Glycine max), due to the absence of sufficient heterogeneous interaction data. We present an alternative solution for inferring the FGNs of soybean (SoyFGNs), in a pioneering study on the soybean interactome, which is also applicable to other organisms. SoyFGNs exhibit the typical characteristics of biological networks: scale-free, small-world architecture and modularization. Verified by co-expression and KEGG pathways, SoyFGNs are more extensive and accurate than an orthology network derived from Arabidopsis. As a case study, network-guided disease-resistance gene discovery indicates that SoyFGNs can provide system-level studies on gene functions and interactions. This work suggests that inferring and modelling the interactome of a non-model plant are feasible. It will speed up the discovery and definition of the functions and interactions of other genes that control important functions, such as nitrogen fixation and protein or lipid synthesis. The efforts of the study are the basis of our further comprehensive studies on the soybean functional interactome at the genome and microRNome levels. Additionally, a web tool for information retrieval and analysis of SoyFGNs can be accessed at SoyFN: http://nclab.hit.edu.cn/SoyFN.

System-Level Insights into the Cellular Interactome of a Non-Model Organism: Inferring, Modelling and Analysing Functional Gene Network of Soybean (Glycine max)

PubMed Central

Xu, Yungang; Guo, Maozu; Zou, Quan; Liu, Xiaoyan; Wang, Chunyu; Liu, Yang

2014-01-01

Cellular interactome, in which genes and/or their products interact on several levels, forming transcriptional regulatory-, protein interaction-, metabolic-, signal transduction networks, etc., has attracted decades of research focuses. However, such a specific type of network alone can hardly explain the various interactive activities among genes. These networks characterize different interaction relationships, implying their unique intrinsic properties and defects, and covering different slices of biological information. Functional gene network (FGN), a consolidated interaction network that models fuzzy and more generalized notion of gene-gene relations, have been proposed to combine heterogeneous networks with the goal of identifying functional modules supported by multiple interaction types. There are yet no successful precedents of FGNs on sparsely studied non-model organisms, such as soybean (Glycine max), due to the absence of sufficient heterogeneous interaction data. We present an alternative solution for inferring the FGNs of soybean (SoyFGNs), in a pioneering study on the soybean interactome, which is also applicable to other organisms. SoyFGNs exhibit the typical characteristics of biological networks: scale-free, small-world architecture and modularization. Verified by co-expression and KEGG pathways, SoyFGNs are more extensive and accurate than an orthology network derived from Arabidopsis. As a case study, network-guided disease-resistance gene discovery indicates that SoyFGNs can provide system-level studies on gene functions and interactions. This work suggests that inferring and modelling the interactome of a non-model plant are feasible. It will speed up the discovery and definition of the functions and interactions of other genes that control important functions, such as nitrogen fixation and protein or lipid synthesis. The efforts of the study are the basis of our further comprehensive studies on the soybean functional interactome at the genome and microRNome levels. Additionally, a web tool for information retrieval and analysis of SoyFGNs can be accessed at SoyFN: http://nclab.hit.edu.cn/SoyFN. PMID:25423109

Magnetic interactions and magnetic anisotropy in exchange coupled 4f-3d systems: a case study of a heterodinuclear Ce3+-Fe3+ cyanide-bridged complex.

PubMed

Sorace, Lorenzo; Sangregorio, Claudio; Figuerola, Albert; Benelli, Cristiano; Gatteschi, Dante

2009-01-01

We report here a detailed single-crystal EPR and magnetic study of a homologous series of complexes of the type Ln-M (Ln = La(III), Ce(III); M = Fe(III), Co(III)). We were able to obtain a detailed picture of the low-lying levels of Ce(III) and Fe(III) centres through the combined use of single-crystal EPR and magnetic susceptibility data. We show that classical ligand field theory can be of great help in rationalising the energies of the low-lying levels of both the transition-metal and rare-earth ions. The combined analysis of single-crystal EPR and magnetic data of the coupled system Ce-Fe confirmed the great complexity of the interactions involving rare-earth elements. With little uncertainty, it turned out clearly that the description of the interaction involving the lowest lying spin levels requires the introduction of the isotropic, anisotropic and antisymmetric terms.

Systems Modeling at Multiple Levels of Regulation: Linking Systems and Genetic Networks to Spatially Explicit Plant Populations

PubMed Central

Kitchen, James L.; Allaby, Robin G.

2013-01-01

Selection and adaptation of individuals to their underlying environments are highly dynamical processes, encompassing interactions between the individual and its seasonally changing environment, synergistic or antagonistic interactions between individuals and interactions amongst the regulatory genes within the individual. Plants are useful organisms to study within systems modeling because their sedentary nature simplifies interactions between individuals and the environment, and many important plant processes such as germination or flowering are dependent on annual cycles which can be disrupted by climate behavior. Sedentism makes plants relevant candidates for spatially explicit modeling that is tied in with dynamical environments. We propose that in order to fully understand the complexities behind plant adaptation, a system that couples aspects from systems biology with population and landscape genetics is required. A suitable system could be represented by spatially explicit individual-based models where the virtual individuals are located within time-variable heterogeneous environments and contain mutable regulatory gene networks. These networks could directly interact with the environment, and should provide a useful approach to studying plant adaptation. PMID:27137364

Protecting quantum coherence of two-level atoms from vacuum fluctuations of electromagnetic field

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

Liu, Xiaobao; Tian, Zehua; Wang, Jieci

In the framework of open quantum systems, we study the dynamics of a static polarizable two-level atom interacting with a bath of fluctuating vacuum electromagnetic field and explore under which conditions the coherence of the open quantum system is unaffected by the environment. For both a single-qubit and two-qubit systems, we find that the quantum coherence cannot be protected from noise when the atom interacts with a non-boundary electromagnetic field. However, with the presence of a boundary, the dynamical conditions for the insusceptible of quantum coherence are fulfilled only when the atom is close to the boundary and is transverselymore » polarizable. Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction. -- Highlights: •We study the dynamics of a two-level atom interacting with a bath of fluctuating vacuum electromagnetic field. •For both a single and two-qubit systems, the quantum coherence cannot be protected from noise without a boundary. •The insusceptible of the quantum coherence can be fulfilled only when the atom is close to the boundary and is transversely polarizable. •Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction.« less

Children’s cortisol and salivary alpha-amylase interact to predict attention bias to threatening stimuli

PubMed Central

Ursache, Alexandra; Blair, Clancy

2017-01-01

Physiological responses to threat occur through both the autonomic nervous system (ANS) and the hypothalamic pituitary adrenal (HPA) axis. Activity in these systems can be measured through salivary alpha-amylase (sAA) and salivary cortisol, respectively. Theoretical work and empirical studies have suggested the importance of examining the coordination of these systems in relation to cognitive functioning and behavior problems. Less is known, however, about whether these systems interactively predict more automatic aspects of attention processing such as attention toward emotionally salient threatening stimuli. We used a dot probe task to assess attention bias toward threatening stimuli in 347 kindergarten children. Cortisol and sAA were assayed from saliva samples collected prior to children’s participation in assessments on a subsequent day. Using regression analyses, we examined relations of sAA and cortisol to attention bias. Results indicate that cortisol and sAA interact in predicting attention bias. Higher levels of cortisol predicted greater bias toward threat for children who had high levels of sAA, but predicted greater bias away from threat for children who had low levels of sAA. These results suggest that greater symmetry in HPA and ANS functioning is associated with greater reliance on automatic attention processes in the face of threat. PMID:25455863

The evolution of ethylene signaling in plant chemical ecology.

PubMed

Groen, Simon C; Whiteman, Noah K

2014-07-01

Ethylene is a key hormone in plant development, mediating plant responses to abiotic environmental stress, and interactions with attackers and mutualists. Here, we provide a synthesis of the role of ethylene in the context of plant ecology and evolution, and a prospectus for future research in this area. We focus on the regulatory function of ethylene in multi-organismal interactions. In general, plant interactions with different types of organisms lead to reduced or enhanced levels of ethylene. This in turn affects not only the plant's response to the interacting organism at hand, but also to other organisms in the community. These community-level effects become observable as enhanced or diminished relationships with future commensals, and systemic resistance or susceptibility to secondary attackers. Ongoing comparative genomic and phenotypic analyses continue to shed light on these interactions. These studies have revealed that plants and interacting organisms from separate kingdoms of life have independently evolved the ability to produce, perceive, and respond to ethylene. This signature of convergent evolution of ethylene signaling at the phenotypic level highlights the central role ethylene metabolism and signaling plays in plant interactions with microbes and animals.

Multi-agent-based bio-network for systems biology: protein-protein interaction network as an example.

PubMed

Ren, Li-Hong; Ding, Yong-Sheng; Shen, Yi-Zhen; Zhang, Xiang-Feng

2008-10-01

Recently, a collective effort from multiple research areas has been made to understand biological systems at the system level. This research requires the ability to simulate particular biological systems as cells, organs, organisms, and communities. In this paper, a novel bio-network simulation platform is proposed for system biology studies by combining agent approaches. We consider a biological system as a set of active computational components interacting with each other and with an external environment. Then, we propose a bio-network platform for simulating the behaviors of biological systems and modelling them in terms of bio-entities and society-entities. As a demonstration, we discuss how a protein-protein interaction (PPI) network can be seen as a society of autonomous interactive components. From interactions among small PPI networks, a large PPI network can emerge that has a remarkable ability to accomplish a complex function or task. We also simulate the evolution of the PPI networks by using the bio-operators of the bio-entities. Based on the proposed approach, various simulators with different functions can be embedded in the simulation platform, and further research can be done from design to development, including complexity validation of the biological system.

Daily social interactions, close relationships, and systemic inflammation in two samples: Healthy middle-aged and older adults.

PubMed

Bajaj, Amoha; John-Henderson, Neha A; Cundiff, Jenny M; Marsland, Anna L; Manuck, Stephen B; Kamarck, Thomas W

2016-11-01

Systemic inflammation is thought to be a biological mediator between social relationship quality and premature mortality. Empirical work has yielded mixed support for an association of social relationship variables with systemic inflammation, perhaps due to methodological limitations. To date, research in this literature has focused on global perceptions of social relationships, with limited attention to the covariance of characteristics of daily social interactions with inflammation. Here, we examine whether daily interactions, as assessed by ecological momentary assessment (EMA), associate with peripheral markers of inflammation among midlife and older adults. Global social support and integration were measured using the Interpersonal Support Evaluation List (ISEL) and the Social Network Index (SNI), respectively, in older adults from the Pittsburgh Healthy Heart Project (PHHP), and in middle-aged adults from the Adult Health and Behavior Project-II (AHAB-II). Using time-sampled EMA, we assessed the proportion of the day spent in positive and negative social interactions. Systemic markers of inflammation were interleukin (IL)-6 and C-reactive protein (CRP). Global measures of support and integration did not associate with inflammation in either sample. In older adults, relative frequency of total positive interactions, those with close others (i.e. spouse, friends, family), and those with coworkers predicted lower concentrations of IL-6 in fully adjusted models, accounting for age, sex, race, education, BMI, smoking and alcohol. In middle-aged adults, relative frequency of positive interactions with close others was also inversely associated with IL-6 level and relative frequency of negative marital interactions was unexpectedly inversely associated with CRP level. Characteristics of daily social interactions among midlife and older adults associate with markers of systemic inflammation that are known to predict risk for cardiovascular disease. Ambulatory measures may better capture health-relevant social processes in daily life than retrospective, global self-report measures. Published by Elsevier Inc.

Agent autonomy approach to probabilistic physics-of-failure modeling of complex dynamic systems with interacting failure mechanisms

NASA Astrophysics Data System (ADS)

Gromek, Katherine Emily

A novel computational and inference framework of the physics-of-failure (PoF) reliability modeling for complex dynamic systems has been established in this research. The PoF-based reliability models are used to perform a real time simulation of system failure processes, so that the system level reliability modeling would constitute inferences from checking the status of component level reliability at any given time. The "agent autonomy" concept is applied as a solution method for the system-level probabilistic PoF-based (i.e. PPoF-based) modeling. This concept originated from artificial intelligence (AI) as a leading intelligent computational inference in modeling of multi agents systems (MAS). The concept of agent autonomy in the context of reliability modeling was first proposed by M. Azarkhail [1], where a fundamentally new idea of system representation by autonomous intelligent agents for the purpose of reliability modeling was introduced. Contribution of the current work lies in the further development of the agent anatomy concept, particularly the refined agent classification within the scope of the PoF-based system reliability modeling, new approaches to the learning and the autonomy properties of the intelligent agents, and modeling interacting failure mechanisms within the dynamic engineering system. The autonomous property of intelligent agents is defined as agent's ability to self-activate, deactivate or completely redefine their role in the analysis. This property of agents and the ability to model interacting failure mechanisms of the system elements makes the agent autonomy fundamentally different from all existing methods of probabilistic PoF-based reliability modeling. 1. Azarkhail, M., "Agent Autonomy Approach to Physics-Based Reliability Modeling of Structures and Mechanical Systems", PhD thesis, University of Maryland, College Park, 2007.

Use case driven approach to develop simulation model for PCS of APR1400 simulator

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

Dong Wook, Kim; Hong Soo, Kim; Hyeon Tae, Kang

2006-07-01

The full-scope simulator is being developed to evaluate specific design feature and to support the iterative design and validation in the Man-Machine Interface System (MMIS) design of Advanced Power Reactor (APR) 1400. The simulator consists of process model, control logic model, and MMI for the APR1400 as well as the Power Control System (PCS). In this paper, a use case driven approach is proposed to develop a simulation model for PCS. In this approach, a system is considered from the point of view of its users. User's view of the system is based on interactions with the system and themore » resultant responses. In use case driven approach, we initially consider the system as a black box and look at its interactions with the users. From these interactions, use cases of the system are identified. Then the system is modeled using these use cases as functions. Lower levels expand the functionalities of each of these use cases. Hence, starting from the topmost level view of the system, we proceeded down to the lowest level (the internal view of the system). The model of the system thus developed is use case driven. This paper will introduce the functionality of the PCS simulation model, including a requirement analysis based on use case and the validation result of development of PCS model. The PCS simulation model using use case will be first used during the full-scope simulator development for nuclear power plant and will be supplied to Shin-Kori 3 and 4 plant. The use case based simulation model development can be useful for the design and implementation of simulation models. (authors)« less

Program (systems) engineering

NASA Technical Reports Server (NTRS)

Baroff, Lynn E.; Easter, Robert W.; Pomphrey, Richard B.

2004-01-01

Program Systems Engineering applies the principles of Systems Engineering at the program level. Space programs are composed of interrelated elements which can include collections of projects, advanced technologies, information systems, etc. Some program elements are outside traditional engineering's physical systems, such as education and public outreach, public relations, resource flow, and interactions within the political environments.

Aldosterone and parathyroid hormone: a precarious couple for cardiovascular disease.

PubMed

Tomaschitz, Andreas; Ritz, Eberhard; Pieske, Burkert; Fahrleitner-Pammer, Astrid; Kienreich, Katharina; Horina, Jörg H; Drechsler, Christiane; März, Winfried; Ofner, Michael; Pieber, Thomas R; Pilz, Stefan

2012-04-01

Animal and human studies support a clinically relevant interaction between aldosterone and parathyroid hormone (PTH) levels and suggest an impact of the interaction on cardiovascular (CV) health. This review focuses on mechanisms behind the bidirectional interactions between aldosterone and PTH and their potential impact on the CV system. There is evidence that PTH increases the secretion of aldosterone from the adrenals directly as well as indirectly by activating the renin-angiotensin system. Upregulation of aldosterone synthesis might contribute to the higher risk of arterial hypertension and of CV damage in patients with primary hyperparathyroidism. Furthermore, parathyroidectomy is followed by decreased blood pressure levels and reduced CV morbidity as well as lower renin and aldosterone levels. In chronic heart failure, the aldosterone activity is inappropriately elevated, causing salt retention; it has been argued that the resulting calcium wasting causes secondary hyperparathyroidism. The ensuing intracellular calcium overload and oxidative stress, caused by PTH and amplified by the relative aldosterone excess, may increase the risk of CV events. In the setting of primary aldosteronism, renal and faecal calcium loss triggers increased PTH secretion which in turn aggravates aldosterone secretion and CV damage. This sequence explains why adrenalectomy and blockade of the mineralocorticoid receptor tend to decrease PTH levels in patients with primary aldosteronism. In view of the reciprocal interaction between aldosterone and PTH and the potentially ensuing CV damage, studies are urgently needed to evaluate diagnostic and therapeutic strategies addressing the interaction between the two hormones.

[Theory of functional systems: postulates and principles of human body construction in health and pathology].

PubMed

Sudakov, K V

2007-01-01

It is shown that many functional systems with different level of organization harmoniously interact in healthy humans and animals. Early stress discoordinates information links of functional systems which can be easily corrected by nonpharmacological methods. Long-term and intensive stress disturbs mechanisms of self-regulation of the weakest functional systems. This converts a pathological process to a molecular tissue level. Principles of systemic functional human organization in pathology and compensation of impaired functions are considered.

The Interaction Between Punishment Sensitivity and Effortful Control for Emerging Adults' Substance Use Behaviors.

PubMed

Kahn, Rachel E; Chiu, Pearl H; Deater-Deckard, Kirby; Hochgraf, Anna K; King-Casas, Brooks; Kim-Spoon, Jungmeen

2018-01-08

Within the dual systems perspective, high reward sensitivity and low punishment sensitivity in conjunction with deficits in cognitive control may contribute to high levels of risk taking, such as substance use. The current study examined whether the individual components of effortful control (inhibitory control, attentional control, and activation control) serve as regulators and moderate the association between reward or punishment sensitivity and substance use behaviors. A total of 1,808 emerging adults from a university setting (Mean age = 19.48; 72% female) completed self-report measures of reward and punishment sensitivity, effortful control, and substance use. Findings indicated significant two-way interactions for punishment sensitivity and inhibitory control for alcohol and marijuana use. The form of these interactions revealed a significant negative association between punishment sensitivity and alcohol and marijuana use at low levels of inhibitory control. No significant interactions emerged for reward sensitivity or other components of effortful control. The current findings provide preliminary evidence suggesting the dual systems theorized to influence risk taking behavior interact to make joint contributions to health risk behaviors such as substance use in emerging adults.

PVC: health implications and production trends.

PubMed Central

Karstadt, M

1976-01-01

Poly(vinyl chloride) (PVC) is a complex plastic system. Individual components of the PVC system, including residual vinyl chloride monomer (RVCM) and certain additives, may pose risks of harm to human health. There have been significant reductions in the RVCM content of PVC resin since 1974, reducing the cancer risk of workers in PVC fabrication plants and consumers of PVC products. A "no-effect" level for vinyl chloride monomer (VCM)-induced carcinogenesis has not been found to date; therefore, the significance of human exposure to low levels of RVCM remains to be determined. Exposure to PVC dust may cause pulmonary dysfunctions. Pulmonary and other possible health effects of PVC dust require further study. The PVC plastics system should be characterized as to interactions among its various components and as to interactions of the components and the PVC system as a whole with biological systems. Images FIGURE 1. FIGURE 2. PMID:799961

Impact of Interactive Aerosol on the African Easterly Jet in the NASA GEOS-5 Global Forecasting System

NASA Technical Reports Server (NTRS)

Reale, O.; Lau, K. M.; da Silva, A.

2010-01-01

The real-time treatment of interactive realistically varying aerosol in a global operational forecasting system, as opposed to prescribed (fixed or climatologically varying) aerosols, is a very difficult challenge that only recently begins to be addressed. Experiment results from a recent version of the NASA GEOS-5 forecasting system, inclusive of interactive aerosol treatment, are presented in this work. Four sets of 30 5-day forecasts are initialized from a high quality set of analyses previously produced and documented to cover the period from 15 August to 16 September 2006, which corresponds to the NASA African Monsoon Multidisciplinary Analysis (NAMMA) observing campaign. The four forecast sets are at two different horizontal resolutions and with and without interactive aerosol treatment. The net impact of aerosol, at times in which there is a strong dust outbreak, is a temperature increase at the dust level and decrease in the near-surface levels, in complete agreement with previous observational and modeling studies. Moreover, forecasts in which interactive aerosols are included depict an African Easterly (AEJ) at slightly higher elevation, and slightly displace northward, with respect to the forecasts in which aerosols are not include. The shift in the AEJ position goes in the direction of observations and agrees with previous results.

Squeezing via two-photon transitions

NASA Astrophysics Data System (ADS)

Savage, C. M.; Walls, D. F.

1986-05-01

The squeezing spectrum for a cavity field mode interacting with an ensemble of three-level 'Lambda-configuration' atoms by an effective two-photon transition is calculated. The advantage of the three-level Lambda system as a squeezing medium, that is, optical nonlinearity without atomic saturation, has recently been pointed out by Reid, Walls, and Dalton. Perfect squeezing is predicted at the turning points for dispersive optical bistability and good squeezing for a range of other cases. Three-level ladder atoms interacting by an effective two-photon transition are also shown to give perfect squeezing in the dispersive limit.

Spectroscopic signatures of localization with interacting photons in superconducting qubits

NASA Astrophysics Data System (ADS)

Roushan, P.; Neill, C.; Tangpanitanon, J.; Bastidas, V. M.; Megrant, A.; Barends, R.; Chen, Y.; Chen, Z.; Chiaro, B.; Dunsworth, A.; Fowler, A.; Foxen, B.; Giustina, M.; Jeffrey, E.; Kelly, J.; Lucero, E.; Mutus, J.; Neeley, M.; Quintana, C.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T.; Neven, H.; Angelakis, D. G.; Martinis, J.

2017-12-01

Quantized eigenenergies and their associated wave functions provide extensive information for predicting the physics of quantum many-body systems. Using a chain of nine superconducting qubits, we implement a technique for resolving the energy levels of interacting photons. We benchmark this method by capturing the main features of the intricate energy spectrum predicted for two-dimensional electrons in a magnetic field—the Hofstadter butterfly. We introduce disorder to study the statistics of the energy levels of the system as it undergoes the transition from a thermalized to a localized phase. Our work introduces a many-body spectroscopy technique to study quantum phases of matter.

[On Two Opposing (Bio)surfaces as Comprehended in Terms of an Extension of the Coulomb-Amontons Law of Friction, with Its Virtual Usefulness for Biotribology in Nanoscale].

PubMed

Gadomski, A; Hladyszowski, J

2015-01-01

An extension of the Coulomb-Amontons law is proposed in terms of an interaction-detail involving renormalization (simplified) n-th level scheme. The coefficient of friction is obtained in a general exponential (nonlinear) form, characteristic of virtually infinite (or, many body) level of the interaction map. Yet, its application for a hydration repulsion bilayered system, prone to facilitated lubrication, is taken as linearly confined, albeit with an inclusion of a decisive repelling force/pressure factor. Some perspectives toward related systems, fairly outside biotribological issues, have been also addressed.

Immune-Neuroendocrine Interactions and Autoimmune Diseases

PubMed Central

Jara, Luis J.; Navarro, Carmen; Medina, Gabriela; Vera-Lastra, Olga; Blanco, Francisco

2006-01-01

The relationship between immune-neuroendocrine system is firmly established. The messengers of this connection are hormones, neuropeptides, neurotransmitters and cytokines. The immune-neuroendocrine system have the capacity to synthesize and release these molecules, which, in turn, can stimulate or suppress the activity of immune or neuroendocrine cells by binding to receptors. In fact, hormones, neuropeptides and neurotransmitters participate in innate and adaptive immune response.Autoimmune rheumatic diseases (ARD) are characterized by aberrant production of pro-inflammatory cytokines, which are a potent activator of the HPA axis. In consequence, high levels of pro-inflammatory hormones such as estrogens and prolactin, and low levels of glucocorticoids, an anti-inflammatory hormone, have been described in the active phase of ARD. In addition, high levels of pro-inflammatory hormones and cytokines have also been frequently detected in organ involvement of patients with ARD, suggesting an abnormal local neuroendocrine immune interaction. There is evidence that hormonal changes may appear before the symptomatic phase of the disease. Therefore, it is possible that a pro-inflammatory hormone favors the rupture of tolerance, which is a key feature of autoimmune diseases. The interactions between the immune-neuroendocrine system have a major impact on our understanding of the pathogenic mechanisms, diagnosis and therapy of ARD. PMID:17162354

Diffusion of multiple species with excluded-volume effects.

PubMed

Bruna, Maria; Chapman, S Jonathan

2012-11-28

Stochastic models of diffusion with excluded-volume effects are used to model many biological and physical systems at a discrete level. The average properties of the population may be described by a continuum model based on partial differential equations. In this paper we consider multiple interacting subpopulations/species and study how the inter-species competition emerges at the population level. Each individual is described as a finite-size hard core interacting particle undergoing brownian motion. The link between the discrete stochastic equations of motion and the continuum model is considered systematically using the method of matched asymptotic expansions. The system for two species leads to a nonlinear cross-diffusion system for each subpopulation, which captures the enhancement of the effective diffusion rate due to excluded-volume interactions between particles of the same species, and the diminishment due to particles of the other species. This model can explain two alternative notions of the diffusion coefficient that are often confounded, namely collective diffusion and self-diffusion. Simulations of the discrete system show good agreement with the analytic results.

Systems Biology Graphical Notation: Entity Relationship language Level 1 Version 2.

PubMed

Sorokin, Anatoly; Le Novère, Nicolas; Luna, Augustin; Czauderna, Tobias; Demir, Emek; Haw, Robin; Mi, Huaiyu; Moodie, Stuart; Schreiber, Falk; Villéger, Alice

2015-09-04

The Systems Biological Graphical Notation (SBGN) is an international community effort for standardized graphical representations of biological pathways and networks. The goal of SBGN is to provide unambiguous pathway and network maps for readers with different scientific backgrounds as well as to support efficient and accurate exchange of biological knowledge between different research communities, industry, and other players in systems biology. Three SBGN languages, Process Description (PD), Entity Relationship (ER) and Activity Flow (AF), allow for the representation of different aspects of biological and biochemical systems at different levels of detail. The SBGN Entity Relationship language (ER) represents biological entities and their interactions and relationships within a network. SBGN ER focuses on all potential relationships between entities without considering temporal aspects. The nodes (elements) describe biological entities, such as proteins and complexes. The edges (connections) provide descriptions of interactions and relationships (or influences), e.g., complex formation, stimulation and inhibition. Among all three languages of SBGN, ER is the closest to protein interaction networks in biological literature and textbooks, but its well-defined semantics offer a superior precision in expressing biological knowledge.

An Approach to the Study of the Interactions between Ellagitannins and Oxygen during Oak Wood Aging.

PubMed

García-Estévez, Ignacio; Alcalde-Eon, Cristina; Martínez-Gil, Ana María; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa; Nevares, Ignacio; Del Alamo-Sanza, María

2017-08-09

During the aging of red wine in oak wood barrels, or in alternative aging systems, interactions between the compounds released from wood, the compounds of the wine, and oxygen can take place. The main objective of the present work was to study oxygen-ellagitannin interactions by monitoring their levels in three model systems, all containing the same amounts of French oak chips and differing only in the oxygen content: total absence, only the oxygen released from the chips, and air-saturated (model systems F, OW, and OS, respectively). This study has highlighted the influence of oxygen in the ellagitannins' evolution and the relevance of the oxygen trapped into the oak chips, reporting for the first time the kinetics of oxygen release to the model wine. Furthermore, the indirect contribution of oxygen to the ellagitannins' disappearance by boosting autoxidative reactions has also been pointed out. Vescalagin seems to be the ellagitannin most affected by the initial oxygen levels.

Multiple time-scales and the developmental dynamics of social systems

PubMed Central

Flack, Jessica C.

2012-01-01

To build a theory of social complexity, we need to understand how aggregate social properties arise from individual interaction rules. Here, I review a body of work on the developmental dynamics of pigtailed macaque social organization and conflict management that provides insight into the mechanistic causes of multi-scale social systems. In this model system coarse-grained, statistical representations of collective dynamics are more predictive of the future state of the system than the constantly in-flux behavioural patterns at the individual level. The data suggest that individuals can perceive and use these representations for strategical decision-making. As an interaction history accumulates the coarse-grained representations consolidate. This constrains individual behaviour and provides the foundations for new levels of organization. The time-scales on which these representations change impact whether the consolidating higher-levels can be modified by individuals and collectively. The time-scales appear to be a function of the ‘coarseness’ of the representations and the character of the collective dynamics over which they are averages. The data suggest that an advantage of multiple timescales is that they allow social systems to balance tradeoffs between predictability and adaptability. I briefly discuss the implications of these findings for cognition, social niche construction and the evolution of new levels of organization in biological systems. PMID:22641819

Multiple time-scales and the developmental dynamics of social systems.

PubMed

Flack, Jessica C

2012-07-05

To build a theory of social complexity, we need to understand how aggregate social properties arise from individual interaction rules. Here, I review a body of work on the developmental dynamics of pigtailed macaque social organization and conflict management that provides insight into the mechanistic causes of multi-scale social systems. In this model system coarse-grained, statistical representations of collective dynamics are more predictive of the future state of the system than the constantly in-flux behavioural patterns at the individual level. The data suggest that individuals can perceive and use these representations for strategical decision-making. As an interaction history accumulates the coarse-grained representations consolidate. This constrains individual behaviour and provides the foundations for new levels of organization. The time-scales on which these representations change impact whether the consolidating higher-levels can be modified by individuals and collectively. The time-scales appear to be a function of the 'coarseness' of the representations and the character of the collective dynamics over which they are averages. The data suggest that an advantage of multiple timescales is that they allow social systems to balance tradeoffs between predictability and adaptability. I briefly discuss the implications of these findings for cognition, social niche construction and the evolution of new levels of organization in biological systems.

Social interactions in virtual reality exposure therapy: A proof-of-concept pilot study.

PubMed

Morina, Nexhmedin; Brinkman, Willem-Paul; Hartanto, Dwi; Kampmann, Isabel L; Emmelkamp, Paul M G

2015-01-01

Research on virtual reality exposure therapy (VRET) has demonstrated good treatment efficacy with regards to several anxiety disorders. Yet, there is lack of knowledge about the value of integrating interaction between clients and virtual humans in VRET. Such interaction might prove effective in treating psychological complaints that involve social interactions, such as social anxiety. A VRET system specifically designed to expose clients with social anxiety disorder to anxiety provoking social situations was applied to 16 and 18 individuals with high and low levels of social anxiety, respectively. Participants engaged in two exposure sessions in several free speech dialogues with virtual humans while being monitored by a therapist. Participants with high levels of social anxiety reported significantly lower levels of social anxiety three months after exposure to two virtual reality interaction sessions than before treatment (p < 0.01). In the group with low levels of social anxiety, no significant change of social anxiety was reported between pre-treatment and follow-up. Additionally, participants in both groups reported higher self-efficacy three months after treatment than before treatment (ps ≤ 0.001). These findings indicate that virtual reality technology that incorporates social interactions may be successfully applied for therapeutic purposes.

General properties of quantum optical systems in a strong field limit

NASA Technical Reports Server (NTRS)

Chumakov, S. M.; Klimov, Andrei B.

1994-01-01

We investigate the dynamics of an arbitrary atomic system (n-level atoms or many n-level atoms) interacting with a resonant quantized mode of an em field. If the initial field state is a coherent state with a large photon number then the system dynamics possesses some general features, independently of the particular structure of the atomic system. Namely, trapping states, factorization of the wave function, collapses and revivals of the atomic energy oscillations are discussed.

Mother-Infant Responsiveness: Timing, Mutual Regulation, and Interactional Context.

ERIC Educational Resources Information Center

Van Egeren, Laurie A,; Barratt, Marguerite S.; Roach, Mary A.

2001-01-01

Investigated from a dynamic systems perspective mutual regulation during naturalistic interaction of mothers with their 4-month-olds. Found that mothers and infants communicated primarily through vocal signals and responses. Levels of contingent responsiveness between partners were significantly associated and occurred within distinct behavioral…

Laboratory simulation of the interaction between a tethered satellite system and the ionosphere

NASA Astrophysics Data System (ADS)

Vannaroni, G.; Giovi, R.; de Venuto, F.

1992-10-01

The authors report on the measurements performed in the IFSI/CNR plasma chamber at Frascati related to the laboratory investigation of the interaction between a plasma source and an ambient plasma of ionospheric type. Such an interaction is of relevant interest for the possibility of using electrodynamic tethered satellite systems, orbiting at ionospheric altitude, for generating electric power or propulsion in space. The interaction region was analyzed at various conditions of ambient magnetic field (/0-0.5/ G) and at different polarization levels of the plasma source (/0-40/ V). The plasma measurements were carried out with a diagnostic system using an array of Langmuir probes movable in the chamber so that a map of the plasma parameters could be obtained at the different experimental conditions.

Exploration of protein-protein interaction effects on α-2-macroglobulin in an inhibition of serine protease through gene expression and molecular simulations studies.

PubMed

Sivakamavalli, Jeyachandran; Selvaraj, Chandrabose; Singh, Sanjeev Kumar; Vaseeharan, Baskaralingam

2014-01-01

In Prophenoloxidase (ProPO) cascade, two targets namely serine protease and α-2-macroglobulin are key regulators involved in the defense system of crustaceans. In biological systems, routine role of cell systems requires the understanding in protein-protein interactions through experimental and theoretical concepts, which might yield useful insights into the cellular responses. Response of cells to regulating the immune system is governed by the interactions-involved biomolecular simulations. Unfortunately, studies on the inhibitors (SP and α-2M) that negatively regulate the proPO system or melanization in penaeid shrimp are not yet available. In order to understand how these interactions change the proPO mechanism in Indian white shrimp Fenneropenaeus indicus was determined. In F. indicus, innate immune system is in a sensitive balance of intricate interactions; elucidating these interactions by the integration of in silico and in vitro has great potential. We have determined the expression of both the SP and α-2M enzymes in regulatory mechanism, which are analyzed through qRT-PCR, protein-protein docking, and simulation studies. From this work, we propose a novel approach for studying an organism at the systems level by integrating genome-wide computational analysis and the gene expression data.

Method for physiologic phenotype characterization at the single-cell level in non-interacting and interacting cells.

PubMed

Kelbauskas, Laimonas; Ashili, Shashanka P; Houkal, Jeff; Smith, Dean; Mohammadreza, Aida; Lee, Kristen B; Forrester, Jessica; Kumar, Ashok; Anis, Yasser H; Paulson, Thomas G; Youngbull, Cody A; Tian, Yanqing; Holl, Mark R; Johnson, Roger H; Meldrum, Deirdre R

2012-03-01

Intercellular heterogeneity is a key factor in a variety of core cellular processes including proliferation, stimulus response, carcinogenesis, and drug resistance. However, cell-to-cell variability studies at the single-cell level have been hampered by the lack of enabling experimental techniques. We present a measurement platform that features the capability to quantify oxygen consumption rates of individual, non-interacting and interacting cells under normoxic and hypoxic conditions. It is based on real-time concentration measurements of metabolites of interest by means of extracellular optical sensors in cell-isolating microwells of subnanoliter volume. We present the results of a series of measurements of oxygen consumption rates (OCRs) of individual non-interacting and interacting human epithelial cells. We measured the effects of cell-to-cell interactions by using the system's capability to isolate two and three cells in a single well. The major advantages of the approach are: 1. ratiometric, intensity-based characterization of the metabolic phenotype at the single-cell level, 2. minimal invasiveness due to the distant positioning of sensors, and 3. ability to study the effects of cell-cell interactions on cellular respiration rates. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE).

The Systemic Interaction of Attachment on Psychophysiological Arousal in Couple Conflict.

PubMed

Taylor, Nathan C; Seedall, Ryan B; Robinson, W David; Bradford, Kay

2018-01-01

Attachment in adult romantic relationships has long been linked to conflict styles. Psychophysiological measures have provided additional insight into this association by accessing less conscious and controlled responses to conflict. The aim of this study was to explore the relationship between attachment anxiety, attachment avoidance, and the interaction between attachment styles on skin conductance responses during conflict and recovery from conflict. Using dyadic analysis of 50 heterosexual couples, we found evidence of a systemic effect of attachment, where psychophysiological arousal increased when one partner had higher levels of attachment anxiety and the other partner had higher levels of attachment avoidance. Attachment avoidance was also negatively associated with increased levels of arousal. Relationship and clinical implications of these findings are discussed. © 2017 American Association for Marriage and Family Therapy.

Exploration Medical System Technical Architecture Overview

NASA Technical Reports Server (NTRS)

Cerro, J.; Rubin, D.; Mindock, J.; Middour, C.; McGuire, K.; Hanson, A.; Reilly, J.; Burba, T.; Urbina, M.

2018-01-01

The Exploration Medical Capability (ExMC) Element Systems Engineering (SE) goals include defining the technical system needed to support medical capabilities for a Mars exploration mission. A draft medical system architecture was developed based on stakeholder needs, system goals, and system behaviors, as captured in an ExMC concept of operations document and a system model. This talk will discuss a high-level view of the medical system, as part of a larger crew health and performance system, both of which will support crew during Deep Space Transport missions. Other mission components, such as the flight system, ground system, caregiver, and patient, will be discussed as aspects of the context because the medical system will have important interactions with each. Additionally, important interactions with other aspects of the crew health and performance system are anticipated, such as health & wellness, mission task performance support, and environmental protection. This talk will highlight areas in which we are working with other disciplines to understand these interactions.

Linking market interaction intensity of 3D Ising type financial model with market volatility

NASA Astrophysics Data System (ADS)

Fang, Wen; Ke, Jinchuan; Wang, Jun; Feng, Ling

2016-11-01

Microscopic interaction models in physics have been used to investigate the complex phenomena of economic systems. The simple interactions involved can lead to complex behaviors and help the understanding of mechanisms in the financial market at a systemic level. This article aims to develop a financial time series model through 3D (three-dimensional) Ising dynamic system which is widely used as an interacting spins model to explain the ferromagnetism in physics. Through Monte Carlo simulations of the financial model and numerical analysis for both the simulation return time series and historical return data of Hushen 300 (HS300) index in Chinese stock market, we show that despite its simplicity, this model displays stylized facts similar to that seen in real financial market. We demonstrate a possible underlying link between volatility fluctuations of real stock market and the change in interaction strengths of market participants in the financial model. In particular, our stochastic interaction strength in our model demonstrates that the real market may be consistently operating near the critical point of the system.

Robustness Elasticity in Complex Networks

PubMed Central

Matisziw, Timothy C.; Grubesic, Tony H.; Guo, Junyu

2012-01-01

Network robustness refers to a network’s resilience to stress or damage. Given that most networks are inherently dynamic, with changing topology, loads, and operational states, their robustness is also likely subject to change. However, in most analyses of network structure, it is assumed that interaction among nodes has no effect on robustness. To investigate the hypothesis that network robustness is not sensitive or elastic to the level of interaction (or flow) among network nodes, this paper explores the impacts of network disruption, namely arc deletion, over a temporal sequence of observed nodal interactions for a large Internet backbone system. In particular, a mathematical programming approach is used to identify exact bounds on robustness to arc deletion for each epoch of nodal interaction. Elasticity of the identified bounds relative to the magnitude of arc deletion is assessed. Results indicate that system robustness can be highly elastic to spatial and temporal variations in nodal interactions within complex systems. Further, the presence of this elasticity provides evidence that a failure to account for nodal interaction can confound characterizations of complex networked systems. PMID:22808060

Untargeted metabolomics studies employing NMR and LC-MS reveal metabolic coupling between Nanoarcheum equitans and its archaeal host Ignicoccus hospitalis.

PubMed

Hamerly, Timothy; Tripet, Brian P; Tigges, Michelle; Giannone, Richard J; Wurch, Louie; Hettich, Robert L; Podar, Mircea; Copié, Valerie; Bothner, Brian

2015-08-01

Interspecies interactions are the basis of microbial community formation and infectious diseases. Systems biology enables the construction of complex models describing such interactions, leading to a better understanding of disease states and communities. However, before interactions between complex organisms can be understood, metabolic and energetic implications of simpler real-world host-microbe systems must be worked out. To this effect, untargeted metabolomics experiments were conducted and integrated with proteomics data to characterize key molecular-level interactions between two hyperthermophilic microbial species, both of which have reduced genomes. Metabolic changes and transfer of metabolites between the archaea Ignicoccus hospitalis and Nanoarcheum equitans were investigated using integrated LC-MS and NMR metabolomics. The study of such a system is challenging, as no genetic tools are available, growth in the laboratory is challenging, and mechanisms by which they interact are unknown. Together with information about relative enzyme levels obtained from shotgun proteomics, the metabolomics data provided useful insights into metabolic pathways and cellular networks of I. hospitalis that are impacted by the presence of N. equitans , including arginine, isoleucine, and CTP biosynthesis. On the organismal level, the data indicate that N. equitans exploits metabolites generated by I. hospitalis to satisfy its own metabolic needs. This finding is based on N. equitans 's consumption of a significant fraction of the metabolite pool in I. hospitalis that cannot solely be attributed to increased biomass production for N. equitans . Combining LC-MS and NMR metabolomics datasets improved coverage of the metabolome and enhanced the identification and quantitation of cellular metabolites.

Untargeted metabolomics studies employing NMR and LC-MS reveal metabolic coupling between Nanoarcheum equitans and its archaeal host Ignicoccus hospitalis

PubMed Central

Hamerly, Timothy; Tripet, Brian P.; Tigges, Michelle; Giannone, Richard J.; Wurch, Louie; Hettich, Robert L.; Podar, Mircea; Copié, Valerie; Bothner, Brian

2014-01-01

Interspecies interactions are the basis of microbial community formation and infectious diseases. Systems biology enables the construction of complex models describing such interactions, leading to a better understanding of disease states and communities. However, before interactions between complex organisms can be understood, metabolic and energetic implications of simpler real-world host-microbe systems must be worked out. To this effect, untargeted metabolomics experiments were conducted and integrated with proteomics data to characterize key molecular-level interactions between two hyperthermophilic microbial species, both of which have reduced genomes. Metabolic changes and transfer of metabolites between the archaea Ignicoccus hospitalis and Nanoarcheum equitans were investigated using integrated LC-MS and NMR metabolomics. The study of such a system is challenging, as no genetic tools are available, growth in the laboratory is challenging, and mechanisms by which they interact are unknown. Together with information about relative enzyme levels obtained from shotgun proteomics, the metabolomics data provided useful insights into metabolic pathways and cellular networks of I. hospitalis that are impacted by the presence of N. equitans, including arginine, isoleucine, and CTP biosynthesis. On the organismal level, the data indicate that N. equitans exploits metabolites generated by I. hospitalis to satisfy its own metabolic needs. This finding is based on N. equitans’s consumption of a significant fraction of the metabolite pool in I. hospitalis that cannot solely be attributed to increased biomass production for N. equitans. Combining LC-MS and NMR metabolomics datasets improved coverage of the metabolome and enhanced the identification and quantitation of cellular metabolites. PMID:26273237

Display formats and commercial vehicle operator (CVO) workload

DOT National Transportation Integrated Search

1997-09-01

The objective of this study was to determine the effects of display modality, level of driver interaction, and amount of information on the driving performance and system operation performance of commercial drivers. Introducing any level of interacti...

Use of computer programs STLK1 and STWT1 for analysis of stream-aquifer hydraulic interaction

USGS Publications Warehouse

Desimone, Leslie A.; Barlow, Paul M.

1999-01-01

Quantifying the hydraulic interaction of aquifers and streams is important in the analysis of stream base fow, flood-wave effects, and contaminant transport between surface- and ground-water systems. This report describes the use of two computer programs, STLK1 and STWT1, to analyze the hydraulic interaction of streams with confined, leaky, and water-table aquifers during periods of stream-stage fuctuations and uniform, areal recharge. The computer programs are based on analytical solutions to the ground-water-flow equation in stream-aquifer settings and calculate ground-water levels, seepage rates across the stream-aquifer boundary, and bank storage that result from arbitrarily varying stream stage or recharge. Analysis of idealized, hypothetical stream-aquifer systems is used to show how aquifer type, aquifer boundaries, and aquifer and streambank hydraulic properties affect aquifer response to stresses. Published data from alluvial and stratifed-drift aquifers in Kentucky, Massachusetts, and Iowa are used to demonstrate application of the programs to field settings. Analytical models of these three stream-aquifer systems are developed on the basis of available hydrogeologic information. Stream-stage fluctuations and recharge are applied to the systems as hydraulic stresses. The models are calibrated by matching ground-water levels calculated with computer program STLK1 or STWT1 to measured ground-water levels. The analytical models are used to estimate hydraulic properties of the aquifer, aquitard, and streambank; to evaluate hydrologic conditions in the aquifer; and to estimate seepage rates and bank-storage volumes resulting from flood waves and recharge. Analysis of field examples demonstrates the accuracy and limitations of the analytical solutions and programs when applied to actual ground-water systems and the potential uses of the analytical methods as alternatives to numerical modeling for quantifying stream-aquifer interactions.

Time-dependent perturbation of a two-state quantum mechanical system

NASA Technical Reports Server (NTRS)

Dion, D. R.

1974-01-01

A two- (nondegenerate) level quantum system interacting with a classical monochromatic radiation field is described. The existing work on this problem is reviewed and some novel aspects of the problems are presented.

Intellectual Development and Interaction Effectiveness with DISCOVER.

ERIC Educational Resources Information Center

Roselle, Bruce E.; Hummel, Thomas J.

1988-01-01

Used Knefelkamp's and Slepitza's (1976) model of career-related intellectual development to investigate how students at different levels of development think as they interact with a computer-assisted career guidance system, DISCOVER II, which comprises modules on understanding interests, values, and abilities; searching for occupations based on…

Fouling of nanofiltration, reverse osmosis, and ultrafiltration membranes by protein mixtures: the role of inter-foulant-species interaction.

PubMed

Wang, Yi-Ning; Tang, Chuyang Y

2011-08-01

Protein fouling of nanofiltration (NF), reverse osmosis (RO), and ultrafiltration (UF) membranes by bovine serum albumin (BSA), lysozyme (LYS), and their mixture was investigated under cross-flow conditions. The effect of solution chemistry, membrane properties, and permeate flux level was systematically studied. When the solution pH was within the isoelectric points (IEPs) of the two proteins (i.e., pH 4.7-10.4), the mixed protein system experienced more severe flux decline compared to the respective single protein systems, which may be attributed to the electrostatic attraction between the negatively charged BSA and positively charged LYS molecules. Unlike a typical single protein system, membrane fouling by BSA-LYS mixture was only weakly dependent on solution pH within this pH range, and increased ionic strength was found to enhance the membrane flux as a result of the suppressed BSA-LYS electrostatic attraction. Membrane fouling was likely controlled by foulant-fouled-membrane interaction under severe fouling conditions (elevated flux level and unfavorable solution chemistry that promotes fouling), whereas it was likely dominated by foulant-clean-membrane interaction under mild fouling conditions. Compared to nonporous NF and RO membranes, the porous UF membrane was more susceptible to dramatic flux decline due to the increased risk of membrane pore plugging. This study reveals that membrane fouling by mixed macromolecules may behave very differently from that by typical single foulant system, especially when the inter-foulant-species interaction dominates over the intra-species interaction in the mixed foulant system.

Interactive Learning Environment: Web-based Virtual Hydrological Simulation System using Augmented and Immersive Reality

NASA Astrophysics Data System (ADS)

Demir, I.

2014-12-01

Recent developments in internet technologies make it possible to manage and visualize large data on the web. Novel visualization techniques and interactive user interfaces allow users to create realistic environments, and interact with data to gain insight from simulations and environmental observations. The hydrological simulation system is a web-based 3D interactive learning environment for teaching hydrological processes and concepts. The simulation systems provides a visually striking platform with realistic terrain information, and water simulation. Students can create or load predefined scenarios, control environmental parameters, and evaluate environmental mitigation alternatives. The web-based simulation system provides an environment for students to learn about the hydrological processes (e.g. flooding and flood damage), and effects of development and human activity in the floodplain. The system utilizes latest web technologies and graphics processing unit (GPU) for water simulation and object collisions on the terrain. Users can access the system in three visualization modes including virtual reality, augmented reality, and immersive reality using heads-up display. The system provides various scenarios customized to fit the age and education level of various users. This presentation provides an overview of the web-based flood simulation system, and demonstrates the capabilities of the system for various visualization and interaction modes.

Abasy Atlas: a comprehensive inventory of systems, global network properties and systems-level elements across bacteria.

PubMed

Ibarra-Arellano, Miguel A; Campos-González, Adrián I; Treviño-Quintanilla, Luis G; Tauch, Andreas; Freyre-González, Julio A

2016-01-01

The availability of databases electronically encoding curated regulatory networks and of high-throughput technologies and methods to discover regulatory interactions provides an invaluable source of data to understand the principles underpinning the organization and evolution of these networks responsible for cellular regulation. Nevertheless, data on these sources never goes beyond the regulon level despite the fact that regulatory networks are complex hierarchical-modular structures still challenging our understanding. This brings the necessity for an inventory of systems across a large range of organisms, a key step to rendering feasible comparative systems biology approaches. In this work, we take the first step towards a global understanding of the regulatory networks organization by making a cartography of the functional architectures of diverse bacteria. Abasy ( A: cross- BA: cteria SY: stems) Atlas provides a comprehensive inventory of annotated functional systems, global network properties and systems-level elements (global regulators, modular genes shaping functional systems, basal machinery genes and intermodular genes) predicted by the natural decomposition approach for reconstructed and meta-curated regulatory networks across a large range of bacteria, including pathogenically and biotechnologically relevant organisms. The meta-curation of regulatory datasets provides the most complete and reliable set of regulatory interactions currently available, which can even be projected into subsets by considering the force or weight of evidence supporting them or the systems that they belong to. Besides, Abasy Atlas provides data enabling large-scale comparative systems biology studies aimed at understanding the common principles and particular lifestyle adaptions of systems across bacteria. Abasy Atlas contains systems and system-level elements for 50 regulatory networks comprising 78 649 regulatory interactions covering 42 bacteria in nine taxa, containing 3708 regulons and 1776 systems. All this brings together a large corpus of data that will surely inspire studies to generate hypothesis regarding the principles governing the evolution and organization of systems and the functional architectures controlling them.Database URL: http://abasy.ccg.unam.mx. © The Author(s) 2016. Published by Oxford University Press.

Outcomes from building system courseware for teaching and testing in a discipline-based human structure curriculum.

PubMed

Reilly, Frank D

2011-01-01

This study investigated the educational benefits of system-based lecture notes and interactive learning objects in a peripheral nervous system component of a traditional first-year medical school human anatomy course. The impetus for the investigation was anecdotal evidence suggesting enhanced learner satisfaction with the learning resources. Retrospective review of existing data from 2006 to 2009 was undertaken to quantify (1) the effects of Web-based system courseware on examination item performance, and (2) differences among learner opinions regarding the benefit level of the five different types of interactive learning objects as evaluated by instructional design questionnaires. Interactive patient-based case studies (IPCS) and review games (Games), simulated interactive patients (SIP), flashcards, and unit quizzes (Quizzes) developed in-house have been peer-reviewed and published in MedEdPORTAL. Statistics included one-way analysis of variance, Tukey's post hoc test, and power meta-analysis (d). Examination item analysis scores remained significantly higher (P ≤ 0.05; d = 0.3938) for learners receiving the instructional treatment incorporating system-based lecture notes and interactive learning objects than for those not receiving this treatment. Using questionnaires with a five-point Likert scale, students reported favorably on the benefit level of all learning objects. They rated the SIP and IPCS significantly higher (P ≤0.05) and games significantly lower (P ≤ 0.05) than in previous years, indicating a change in learner preferences. This study reaffirms that online system-based instructional techniques improve student examination performance and overall student satisfaction. Learners indicated stronger preferences for SIP and IPCS over exercises encouraging passive memorization of anatomical content. Copyright © 2011 American Association of Anatomists.

Model-based video segmentation for vision-augmented interactive games

NASA Astrophysics Data System (ADS)

Liu, Lurng-Kuo

2000-04-01

This paper presents an architecture and algorithms for model based video object segmentation and its applications to vision augmented interactive game. We are especially interested in real time low cost vision based applications that can be implemented in software in a PC. We use different models for background and a player object. The object segmentation algorithm is performed in two different levels: pixel level and object level. At pixel level, the segmentation algorithm is formulated as a maximizing a posteriori probability (MAP) problem. The statistical likelihood of each pixel is calculated and used in the MAP problem. Object level segmentation is used to improve segmentation quality by utilizing the information about the spatial and temporal extent of the object. The concept of an active region, which is defined based on motion histogram and trajectory prediction, is introduced to indicate the possibility of a video object region for both background and foreground modeling. It also reduces the overall computation complexity. In contrast with other applications, the proposed video object segmentation system is able to create background and foreground models on the fly even without introductory background frames. Furthermore, we apply different rate of self-tuning on the scene model so that the system can adapt to the environment when there is a scene change. We applied the proposed video object segmentation algorithms to several prototype virtual interactive games. In our prototype vision augmented interactive games, a player can immerse himself/herself inside a game and can virtually interact with other animated characters in a real time manner without being constrained by helmets, gloves, special sensing devices, or background environment. The potential applications of the proposed algorithms including human computer gesture interface and object based video coding such as MPEG-4 video coding.

Network Control Center User Planning System (NCC UPS)

NASA Astrophysics Data System (ADS)

Dealy, Brian

1991-09-01

NCC UPS is presented in the form of the viewgraphs. The following subject areas are covered: UPS overview; NCC UPS role; major NCC UPS functional requirements; interactive user access levels; UPS interfaces; interactive user subsystem; interface navigation; scheduling screen hierarchy; interactive scheduling input panels; autogenerated schedule request panel; schedule data tabular display panel; schedule data graphic display panel; graphic scheduling aid design; and schedule data graphic display.

Network Control Center User Planning System (NCC UPS)

NASA Technical Reports Server (NTRS)

Dealy, Brian

1991-01-01

NCC UPS is presented in the form of the viewgraphs. The following subject areas are covered: UPS overview; NCC UPS role; major NCC UPS functional requirements; interactive user access levels; UPS interfaces; interactive user subsystem; interface navigation; scheduling screen hierarchy; interactive scheduling input panels; autogenerated schedule request panel; schedule data tabular display panel; schedule data graphic display panel; graphic scheduling aid design; and schedule data graphic display.

Biodiversity and the Lotka-Volterra theory of species interactions: open systems and the distribution of logarithmic densities.

PubMed Central

Wilson, William G.; Lundberg, Per

2004-01-01

Theoretical interest in the distributions of species abundances observed in ecological communities has focused recently on the results of models that assume all species are identical in their interactions with one another, and rely upon immigration and speciation to promote coexistence. Here we examine a one-trophic level system with generalized species interactions, including species-specific intraspecific and interspecific interaction strengths, and density-independent immigration from a regional species pool. Comparisons between results from numerical integrations and an approximate analytic calculation for random communities demonstrate good agreement, and both approaches yield abundance distributions of nearly arbitrary shape, including bimodality for intermediate immigration rates. PMID:15347523

Biodiversity and the Lotka-Volterra theory of species interactions: open systems and the distribution of logarithmic densities.

PubMed

Wilson, William G; Lundberg, Per

2004-09-22

Theoretical interest in the distributions of species abundances observed in ecological communities has focused recently on the results of models that assume all species are identical in their interactions with one another, and rely upon immigration and speciation to promote coexistence. Here we examine a one-trophic level system with generalized species interactions, including species-specific intraspecific and interspecific interaction strengths, and density-independent immigration from a regional species pool. Comparisons between results from numerical integrations and an approximate analytic calculation for random communities demonstrate good agreement, and both approaches yield abundance distributions of nearly arbitrary shape, including bimodality for intermediate immigration rates.

Investigating the interactions of decentralized and centralized wastewater heat recovery systems.

PubMed

Sitzenfrei, Robert; Hillebrand, Sebastian; Rauch, Wolfgang

2017-03-01

In the urban water cycle there are different sources for extracting energy. In addition to potential and chemical energy in the wastewater, thermal energy can also be recovered. Heat can be recovered from the wastewater with heat exchangers that are located decentralized and/or centralized at several locations throughout the system. It can be recovered directly at the source (e.g. in the showers and bathrooms), at building block level (e.g. warm water tanks collecting all grey water), in sewers or at the wastewater treatment plant. However, an uncoordinated installation of systems on such different levels can lead to competing technologies. To investigate these interactions, a modelling environment is set up, tested and calibrated based on continuous sewer temperature and flow measurements. With that approach different heat recovery scenarios on a household level (decentralized) and of in-sewer heat recovery (centralized) are investigated. A maximum performance drop of 40% for a centralized energy recovery system was estimated when all bathrooms are equipped with decentralized recovery systems. Therefore, the proposed modelling approach is suitable for testing different future conditions and to identify robust strategies for heat recovery systems from wastewater.

A systems-level approach for investigating organophosphorus pesticide toxicity.

PubMed

Zhu, Jingbo; Wang, Jing; Ding, Yan; Liu, Baoyue; Xiao, Wei

2018-03-01

The full understanding of the single and joint toxicity of a variety of organophosphorus (OP) pesticides is still unavailable, because of the extreme complex mechanism of action. This study established a systems-level approach based on systems toxicology to investigate OP pesticide toxicity by incorporating ADME/T properties, protein prediction, and network and pathway analysis. The results showed that most OP pesticides are highly toxic according to the ADME/T parameters, and can interact with significant receptor proteins to cooperatively lead to various diseases by the established OP pesticide -protein and protein-disease networks. Furthermore, the studies that multiple OP pesticides potentially act on the same receptor proteins and/or the functionally diverse proteins explained that multiple OP pesticides could mutually enhance toxicological synergy or additive on a molecular/systematic level. To the end, the integrated pathways revealed the mechanism of toxicity of the interaction of OP pesticides and elucidated the pathogenesis induced by OP pesticides. This study demonstrates a systems-level approach for investigating OP pesticide toxicity that can be further applied to risk assessments of various toxins, which is of significant interest to food security and environmental protection. Copyright © 2017 Elsevier Inc. All rights reserved.

Engineering computer graphics in gas turbine engine design, analysis and manufacture

NASA Technical Reports Server (NTRS)

Lopatka, R. S.

1975-01-01

A time-sharing and computer graphics facility designed to provide effective interactive tools to a large number of engineering users with varied requirements was described. The application of computer graphics displays at several levels of hardware complexity and capability is discussed, with examples of graphics systems tracing gas turbine product development, beginning with preliminary design through manufacture. Highlights of an operating system stylized for interactive engineering graphics is described.

Random catalytic reaction networks

NASA Astrophysics Data System (ADS)

Stadler, Peter F.; Fontana, Walter; Miller, John H.

1993-03-01

We study networks that are a generalization of replicator (or Lotka-Volterra) equations. They model the dynamics of a population of object types whose binary interactions determine the specific type of interaction product. Such a system always reduces its dimension to a subset that contains production pathways for all of its members. The network equation can be rewritten at a level of collectives in terms of two basic interaction patterns: replicator sets and cyclic transformation pathways among sets. Although the system contains well-known cases that exhibit very complicated dynamics, the generic behavior of randomly generated systems is found (numerically) to be extremely robust: convergence to a globally stable rest point. It is easy to tailor networks that display replicator interactions where the replicators are entire self-sustaining subsystems, rather than structureless units. A numerical scan of random systems highlights the special properties of elementary replicators: they reduce the effective interconnectedness of the system, resulting in enhanced competition, and strong correlations between the concentrations.

Engineering Design Thinking

ERIC Educational Resources Information Center

Lammi, Matthew; Becker, Kurt

2013-01-01

Engineering design thinking is "a complex cognitive process" including divergence-convergence, a systems perspective, ambiguity, and collaboration (Dym, Agogino, Eris, Frey, & Leifer, 2005, p. 104). Design is often complex, involving multiple levels of interacting components within a system that may be nested within or connected to other systems.…

Network Analysis of Drug-target Interactions: A Study on FDA-approved New Molecular Entities Between 2000 to 2015.

PubMed

Lin, Hui-Heng; Zhang, Le-Le; Yan, Ru; Lu, Jin-Jian; Hu, Yuanjia

2017-09-25

The U.S. Food and Drug Administration (FDA) approves new drugs every year. Drug targets are some of the most important interactive molecules for drugs, as they have a significant impact on the therapeutic effects of drugs. In this work, we thoroughly analyzed the data of small molecule drugs approved by the U.S. FDA between 2000 and 2015. Specifically, we focused on seven classes of new molecular entity (NME) classified by the anatomic therapeutic chemical (ATC) classification system. They were NMEs and their corresponding targets for the cardiovascular system, respiratory system, nerve system, general anti-infective systemic, genito-urinary system and sex hormones, alimentary tract and metabolisms, and antineoplastic and immunomodulating agents. To study the drug-target interaction on the systems level, we employed network topological analysis and multipartite network projections. As a result, the drug-target relations of different kinds of drugs were comprehensively characterized and global pictures of drug-target, drug-drug, and target-target interactions were visualized and analyzed from the perspective of network models.

Systems medicine: a new approach to clinical practice.

PubMed

Cardinal-Fernández, Pablo; Nin, Nicolás; Ruíz-Cabello, Jesús; Lorente, José A

2014-10-01

Most respiratory diseases are considered complex diseases as their susceptibility and outcomes are determined by the interaction between host-dependent factors (genetic factors, comorbidities, etc.) and environmental factors (exposure to microorganisms or allergens, treatments received, etc.) The reductionist approach in the study of diseases has been of fundamental importance for the understanding of the different components of a system. Systems biology or systems medicine is a complementary approach aimed at analyzing the interactions between the different components within one organizational level (genome, transcriptome, proteome), and then between the different levels. Systems medicine is currently used for the interpretation and understanding of the pathogenesis and pathophysiology of different diseases, biomarker discovery, design of innovative therapeutic targets, and the drawing up of computational models for different biological processes. In this review we discuss the most relevant concepts of the theory underlying systems medicine, as well as its applications in the various biological processes in humans. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

Dietary protein restriction causes modification in aluminum-induced alteration in glutamate and GABA system of rat brain

PubMed Central

Nayak, Prasunpriya; Chatterjee, Ajay K

2003-01-01

Background Alteration of glutamate and γ-aminobutyrate system have been reported to be associated with neurodegenerative disorders and have been postulated to be involved in aluminum-induced neurotoxicity as well. Aluminum, an well known and commonly exposed neurotoxin, was found to alter glutamate and γ-aminobutyrate levels as well as activities of associated enzymes with regional specificity. Protein malnutrition also reported to alter glutamate level and some of its metabolic enzymes. Thus the region-wise study of levels of brain glutamate and γ-aminobutyrate system in protein adequacy and inadequacy may be worthwhile to understand the mechanism of aluminum-induced neurotoxicity. Results Protein restriction does not have any significant impact on regional aluminum and γ-aminobutyrate contents of rat brain. Significant interaction of dietary protein restriction and aluminum intoxication to alter regional brain glutamate level was observed in the tested brain regions except cerebellum. Alteration in glutamate α-decarboxylase and γ-aminobutyrate transaminase activities were found to be significantly influenced by interaction of aluminum intoxication and dietary protein restriction in all the tested brain regions. In case of regional brain succinic semialdehyde content, this interaction was significant only in cerebrum and thalamic area. Conclusion The alterations of regional brain glutamate and γ-aminobutyrate levels by aluminum are region specific as well as dependent on dietary protein intake. The impact of aluminum exposure on the metabolism of these amino acid neurotransmitters are also influenced by dietary protein level. Thus, modification of dietary protein level or manipulation of the brain amino acid homeostasis by any other means may be an useful tool to find out a path to restrict amino acid neurotransmitter alterations in aluminum-associated neurodisorders. PMID:12657166

Approximation method for a spherical bound system in the quantum plasma

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

Mehramiz, A.; Sobhanian, S.; Mahmoodi, J.

2010-08-15

A system of quantum hydrodynamic equations has been used for investigating the dielectric tensor and dispersion equation of a semiconductor as a quantum magnetized plasma. Dispersion relations and their modifications due to quantum effects are derived for both longitudinal and transverse waves. The number of states and energy levels are analytically estimated for a spherical bound system embedded in a semiconductor quantum plasma. The results show that longitudinal waves decay rapidly and do not interact with the spherical bound system. The energy shifts caused by the spin-orbit interaction and the Zeeman effect are calculated.

Contextualised Skill Acquisition Research: A New Framework to Study the Development of Sport Expertise

ERIC Educational Resources Information Center

Uehara, Luiz; Button, Chris; Falcous, Mark; Davids, Keith

2016-01-01

Background: Under the view of dynamical system theory, expertise in sports emerges from the interaction of multiple constraints. At an individual level, important interactions amongst constraints could include the relationships that evolve between one's family, playmates/coaches, and specific training activities. Or more broadly, other…

A Vision for Co-optimized T&D System Interaction with Renewables and Demand Response

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

Anderson, Lindsay; Zéphyr, Luckny; Cardell, Judith B.

The evolution of the power system to the reliable, efficient and sustainable system of the future will involve development of both demand- and supply-side technology and operations. The use of demand response to counterbalance the intermittency of renewable generation brings the consumer into the spotlight. Though individual consumers are interconnected at the low-voltage distribution system, these resources are typically modeled as variables at the transmission network level. In this paper, a vision for cooptimized interaction of distribution systems, or microgrids, with the high-voltage transmission system is described. In this framework, microgrids encompass consumers, distributed renewables and storage. The energy managementmore » system of the microgrid can also sell (buy) excess (necessary) energy from the transmission system. Preliminary work explores price mechanisms to manage the microgrid and its interactions with the transmission system. Wholesale market operations are addressed through the development of scalable stochastic optimization methods that provide the ability to co-optimize interactions between the transmission and distribution systems. Modeling challenges of the co-optimization are addressed via solution methods for large-scale stochastic optimization, including decomposition and stochastic dual dynamic programming.« less

A Vision for Co-optimized T&D System Interaction with Renewables and Demand Response

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

Anderson, C. Lindsay; Zéphyr, Luckny; Liu, Jialin

The evolution of the power system to the reliable, effi- cient and sustainable system of the future will involve development of both demand- and supply-side technology and operations. The use of demand response to counterbalance the intermittency of re- newable generation brings the consumer into the spotlight. Though individual consumers are interconnected at the low-voltage distri- bution system, these resources are typically modeled as variables at the transmission network level. In this paper, a vision for co- optimized interaction of distribution systems, or microgrids, with the high-voltage transmission system is described. In this frame- work, microgrids encompass consumers, distributed renewablesmore » and storage. The energy management system of the microgrid can also sell (buy) excess (necessary) energy from the transmission system. Preliminary work explores price mechanisms to manage the microgrid and its interactions with the transmission system. Wholesale market operations are addressed through the devel- opment of scalable stochastic optimization methods that provide the ability to co-optimize interactions between the transmission and distribution systems. Modeling challenges of the co-optimization are addressed via solution methods for large-scale stochastic op- timization, including decomposition and stochastic dual dynamic programming.« less

Synthetic Landau Levels and Spinor Vortex Matter on a Haldane Spherical Surface with a Magnetic Monopole.

PubMed

Zhou, Xiang-Fa; Wu, Congjun; Guo, Guang-Can; Wang, Ruquan; Pu, Han; Zhou, Zheng-Wei

2018-03-30

We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by applying the Floquet engineering of a magnetic quadrupole field to create a synthetic monopole field in real space. The system can be exactly mapped to the electron-monopole system on a sphere, thus realizing Haldane's spherical geometry for fractional quantum Hall physics. This method works for either bosons or fermions. We investigate the ground-state vortex pattern for an s-wave interacting atomic condensate by mapping this system to the classical Thompson's problem. The distortion and stability of the vortex pattern are further studied in the presence of dipolar interaction. Our scheme is compatible with the current experimental setup, and may serve as a promising route of investigating quantum Hall physics and exotic spinor vortex matter on curved space.

Toward a Systems Approach to Enteric Pathogen Transmission: From Individual Independence to Community Interdependence

PubMed Central

Eisenberg, Joseph N.S.; Trostle, James; Sorensen, Reed J.D.; Shields, Katherine F.

2012-01-01

Diarrheal disease is still a major cause of mortality and morbidity worldwide; thus a large body of research has been produced describing its risks. We review more than four decades of literature on diarrheal disease epidemiology. These studies detail a progression in the conceptual understanding of transmission of enteric pathogens and demonstrate that diarrheal disease is caused by many interdependent pathways. However, arguments by diarrheal disease researchers in favor of attending to interaction and interdependencies have only recently yielded more formal systems-level approaches. Therefore, interdependence has not yet been highlighted in significant new research initiatives or policy decisions. We argue for a systems-level framework that will contextualize transmission and inform prevention and control efforts so that they can integrate transmission pathways. These systems approaches should be employed to account for community effects (i.e., interactions among individuals and/or households). PMID:22224881

Synthetic Landau Levels and Spinor Vortex Matter on a Haldane Spherical Surface with a Magnetic Monopole

NASA Astrophysics Data System (ADS)

Zhou, Xiang-Fa; Wu, Congjun; Guo, Guang-Can; Wang, Ruquan; Pu, Han; Zhou, Zheng-Wei

2018-03-01

We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by applying the Floquet engineering of a magnetic quadrupole field to create a synthetic monopole field in real space. The system can be exactly mapped to the electron-monopole system on a sphere, thus realizing Haldane's spherical geometry for fractional quantum Hall physics. This method works for either bosons or fermions. We investigate the ground-state vortex pattern for an s -wave interacting atomic condensate by mapping this system to the classical Thompson's problem. The distortion and stability of the vortex pattern are further studied in the presence of dipolar interaction. Our scheme is compatible with the current experimental setup, and may serve as a promising route of investigating quantum Hall physics and exotic spinor vortex matter on curved space.

Cellular automata with object-oriented features for parallel molecular network modeling.

PubMed

Zhu, Hao; Wu, Yinghui; Huang, Sui; Sun, Yan; Dhar, Pawan

2005-06-01

Cellular automata are an important modeling paradigm for studying the dynamics of large, parallel systems composed of multiple, interacting components. However, to model biological systems, cellular automata need to be extended beyond the large-scale parallelism and intensive communication in order to capture two fundamental properties characteristic of complex biological systems: hierarchy and heterogeneity. This paper proposes extensions to a cellular automata language, Cellang, to meet this purpose. The extended language, with object-oriented features, can be used to describe the structure and activity of parallel molecular networks within cells. Capabilities of this new programming language include object structure to define molecular programs within a cell, floating-point data type and mathematical functions to perform quantitative computation, message passing capability to describe molecular interactions, as well as new operators, statements, and built-in functions. We discuss relevant programming issues of these features, including the object-oriented description of molecular interactions with molecule encapsulation, message passing, and the description of heterogeneity and anisotropy at the cell and molecule levels. By enabling the integration of modeling at the molecular level with system behavior at cell, tissue, organ, or even organism levels, the program will help improve our understanding of how complex and dynamic biological activities are generated and controlled by parallel functioning of molecular networks. Index Terms-Cellular automata, modeling, molecular network, object-oriented.

On the physical origin of blue-shifted hydrogen bonds.

PubMed

Li, Xiaosong; Liu, Lei; Schlegel, H Bernhard

2002-08-14

For blue-shifted hydrogen-bonded systems, the hydrogen stretching frequency increases rather than decreases on complexation. In computations at various levels of theory, the blue-shift in the archetypical system, F(3)C-H.FH, is reproduced at the Hartree-Fock level, indicating that electron correlation is not the primary cause. Calculations also demonstrate that a blue-shift does not require either a carbon center or the absence of a lone pair on the proton donor, because F(3)Si-H.OH(2), F(2)NH.FH, F(2)PH.NH(3), and F(2)PH.OH(2) have substantial blue-shifts. Orbital interactions are shown to lengthen the X-H bond and lower its vibrational frequency, and thus cannot be the source of the blue-shift. In the F(3)CH.FH system, the charge redistribution in F(3)CH can be reproduced very well by replacing the FH with a simple dipole, which suggests that the interactions are predominantly electrostatic. When modeled with a point charge for the proton acceptor, attractive electrostatic interactions elongate the F(3)C-H, while repulsive interactions shorten it. At the equilibrium geometry of a hydrogen-bonded complex, the electrostatic attraction between the dipole moments of the proton donor and proton acceptor must be balanced by the Pauli repulsion between the two fragments. In the absence of orbital interactions that cause bond elongation, this repulsive interaction leads to compression of the X-H bond and a blue-shift in its vibrational frequency.

Topological, functional, and dynamic properties of the protein interaction networks rewired by benzo(a)pyrene

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

Ba, Qian; Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing; Li, Junyang

2015-03-01

Benzo(a)pyrene is a common environmental and foodborne pollutant that has been identified as a human carcinogen. Although the carcinogenicity of benzo(a)pyrene has been extensively reported, its precise molecular mechanisms and the influence on system-level protein networks are not well understood. To investigate the system-level influence of benzo(a)pyrene on protein interactions and regulatory networks, a benzo(a)pyrene-rewired protein interaction network was constructed based on 769 key proteins derived from more than 500 literature reports. The protein interaction network rewired by benzo(a)pyrene was a scale-free, highly-connected biological system. Ten modules were identified, and 25 signaling pathways were enriched, most of which belong tomore » the human diseases category, especially cancer and infectious disease. In addition, two lung-specific and two liver-specific pathways were identified. Three pathways were specific in short and medium-term networks (< 48 h), and five pathways were enriched only in the medium-term network (6 h–48 h). Finally, the expression of linker genes in the network was validated by Western blotting. These findings establish the overall, tissue- and time-specific benzo(a)pyrene-rewired protein interaction networks and provide insights into the biological effects and molecular mechanisms of action of benzo(a)pyrene. - Highlights: • Benzo(a)pyrene induced scale-free, highly-connected protein interaction networks. • 25 signaling pathways were enriched through modular analysis. • Tissue- and time-specific pathways were identified.« less

Hydrographs Showing Ground-Water Level Changes for Selected Wells in the Lower Skagit River Basin, Washington

USGS Publications Warehouse

Fasser, E.T.; Julich, R.J.

2009-01-01

Hydrographs for selected wells in the Lower Skagit River basin, Washington, are presented in an interactive web-based map to illustrate monthly and seasonal changes in ground-water levels in the study area. Ground-water level data and well information were collected by the U.S. Geological Survey using standard techniques and were stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Systems-Level Analysis of Innate Immunity

PubMed Central

Zak, Daniel E.; Tam, Vincent C.; Aderem, Alan

2014-01-01

Systems-level analysis of biological processes strives to comprehensively and quantitatively evaluate the interactions between the relevant molecular components over time, thereby enabling development of models that can be employed to ultimately predict behavior. Rapid development in measurement technologies (omics), when combined with the accessible nature of the cellular constituents themselves, is allowing the field of innate immunity to take significant strides toward this lofty goal. In this review, we survey exciting results derived from systems biology analyses of the immune system, ranging from gene regulatory networks to influenza pathogenesis and systems vaccinology. PMID:24655298

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

Rebolini, Elisa, E-mail: rebolini@lct.jussieu.fr; Toulouse, Julien, E-mail: julien.toulouse@upmc.fr; Savin, Andreas, E-mail: savin@lct.jussieu.fr

We present a study of the variation of total energies and excitation energies along a range-separated adiabatic connection. This connection links the non-interacting Kohn–Sham electronic system to the physical interacting system by progressively switching on the electron–electron interactions whilst simultaneously adjusting a one-electron effective potential so as to keep the ground-state density constant. The interactions are introduced in a range-dependent manner, first introducing predominantly long-range, and then all-range, interactions as the physical system is approached, as opposed to the conventional adiabatic connection where the interactions are introduced by globally scaling the standard Coulomb interaction. Reference data are reported for themore » He and Be atoms and the H{sub 2} molecule, obtained by calculating the short-range effective potential at the full configuration-interaction level using Lieb's Legendre-transform approach. As the strength of the electron–electron interactions increases, the excitation energies, calculated for the partially interacting systems along the adiabatic connection, offer increasingly accurate approximations to the exact excitation energies. Importantly, the excitation energies calculated at an intermediate point of the adiabatic connection are much better approximations to the exact excitation energies than are the corresponding Kohn–Sham excitation energies. This is particularly evident in situations involving strong static correlation effects and states with multiple excitation character, such as the dissociating H{sub 2} molecule. These results highlight the utility of long-range interacting reference systems as a starting point for the calculation of excitation energies and are of interest for developing and analyzing practical approximate range-separated density-functional methodologies.« less

Nonresonant interaction of ultrashort electromagnetic pulses with multilevel quantum systems

NASA Technical Reports Server (NTRS)

Belenov, E.; Isakov, V.; Nazarkin, A.

1994-01-01

Some features of the excitation of multilevel quantum systems under the action of electromagnetic pulses which are shorter than the inverse frequency of interlevel transitions are considered. It is shown that the interaction is characterized by a specific type of selectivity which is not connected with the resonant absorption of radiation. The simplest three-level model displays the inverse population of upper levels. The effect of an ultrashort laser pulse on a multilevel molecule was regarded as an instant reception of the oscillation velocity by the oscillator and this approach showed an effective excitation and dissociation of the molecule. The estimations testify to the fact that these effects can be observed using modern femtosecond lasers.

FUSE: a profit maximization approach for functional summarization of biological networks.

PubMed

Seah, Boon-Siew; Bhowmick, Sourav S; Dewey, C Forbes; Yu, Hanry

2012-03-21

The availability of large-scale curated protein interaction datasets has given rise to the opportunity to investigate higher level organization and modularity within the protein interaction network (PPI) using graph theoretic analysis. Despite the recent progress, systems level analysis of PPIS remains a daunting task as it is challenging to make sense out of the deluge of high-dimensional interaction data. Specifically, techniques that automatically abstract and summarize PPIS at multiple resolutions to provide high level views of its functional landscape are still lacking. We present a novel data-driven and generic algorithm called FUSE (Functional Summary Generator) that generates functional maps of a PPI at different levels of organization, from broad process-process level interactions to in-depth complex-complex level interactions, through a pro t maximization approach that exploits Minimum Description Length (MDL) principle to maximize information gain of the summary graph while satisfying the level of detail constraint. We evaluate the performance of FUSE on several real-world PPIS. We also compare FUSE to state-of-the-art graph clustering methods with GO term enrichment by constructing the biological process landscape of the PPIS. Using AD network as our case study, we further demonstrate the ability of FUSE to quickly summarize the network and identify many different processes and complexes that regulate it. Finally, we study the higher-order connectivity of the human PPI. By simultaneously evaluating interaction and annotation data, FUSE abstracts higher-order interaction maps by reducing the details of the underlying PPI to form a functional summary graph of interconnected functional clusters. Our results demonstrate its effectiveness and superiority over state-of-the-art graph clustering methods with GO term enrichment.

Comprehensive curation and analysis of global interaction networks in Saccharomyces cerevisiae

PubMed Central

Reguly, Teresa; Breitkreutz, Ashton; Boucher, Lorrie; Breitkreutz, Bobby-Joe; Hon, Gary C; Myers, Chad L; Parsons, Ainslie; Friesen, Helena; Oughtred, Rose; Tong, Amy; Stark, Chris; Ho, Yuen; Botstein, David; Andrews, Brenda; Boone, Charles; Troyanskya, Olga G; Ideker, Trey; Dolinski, Kara; Batada, Nizar N; Tyers, Mike

2006-01-01

Background The study of complex biological networks and prediction of gene function has been enabled by high-throughput (HTP) methods for detection of genetic and protein interactions. Sparse coverage in HTP datasets may, however, distort network properties and confound predictions. Although a vast number of well substantiated interactions are recorded in the scientific literature, these data have not yet been distilled into networks that enable system-level inference. Results We describe here a comprehensive database of genetic and protein interactions, and associated experimental evidence, for the budding yeast Saccharomyces cerevisiae, as manually curated from over 31,793 abstracts and online publications. This literature-curated (LC) dataset contains 33,311 interactions, on the order of all extant HTP datasets combined. Surprisingly, HTP protein-interaction datasets currently achieve only around 14% coverage of the interactions in the literature. The LC network nevertheless shares attributes with HTP networks, including scale-free connectivity and correlations between interactions, abundance, localization, and expression. We find that essential genes or proteins are enriched for interactions with other essential genes or proteins, suggesting that the global network may be functionally unified. This interconnectivity is supported by a substantial overlap of protein and genetic interactions in the LC dataset. We show that the LC dataset considerably improves the predictive power of network-analysis approaches. The full LC dataset is available at the BioGRID () and SGD () databases. Conclusion Comprehensive datasets of biological interactions derived from the primary literature provide critical benchmarks for HTP methods, augment functional prediction, and reveal system-level attributes of biological networks. PMID:16762047

Agent-based model with multi-level herding for complex financial systems

NASA Astrophysics Data System (ADS)

Chen, Jun-Jie; Tan, Lei; Zheng, Bo

2015-02-01

In complex financial systems, the sector structure and volatility clustering are respectively important features of the spatial and temporal correlations. However, the microscopic generation mechanism of the sector structure is not yet understood. Especially, how to produce these two features in one model remains challenging. We introduce a novel interaction mechanism, i.e., the multi-level herding, in constructing an agent-based model to investigate the sector structure combined with volatility clustering. According to the previous market performance, agents trade in groups, and their herding behavior comprises the herding at stock, sector and market levels. Further, we propose methods to determine the key model parameters from historical market data, rather than from statistical fitting of the results. From the simulation, we obtain the sector structure and volatility clustering, as well as the eigenvalue distribution of the cross-correlation matrix, for the New York and Hong Kong stock exchanges. These properties are in agreement with the empirical ones. Our results quantitatively reveal that the multi-level herding is the microscopic generation mechanism of the sector structure, and provide new insight into the spatio-temporal interactions in financial systems at the microscopic level.

Agent-based model with multi-level herding for complex financial systems

PubMed Central

Chen, Jun-Jie; Tan, Lei; Zheng, Bo

2015-01-01

In complex financial systems, the sector structure and volatility clustering are respectively important features of the spatial and temporal correlations. However, the microscopic generation mechanism of the sector structure is not yet understood. Especially, how to produce these two features in one model remains challenging. We introduce a novel interaction mechanism, i.e., the multi-level herding, in constructing an agent-based model to investigate the sector structure combined with volatility clustering. According to the previous market performance, agents trade in groups, and their herding behavior comprises the herding at stock, sector and market levels. Further, we propose methods to determine the key model parameters from historical market data, rather than from statistical fitting of the results. From the simulation, we obtain the sector structure and volatility clustering, as well as the eigenvalue distribution of the cross-correlation matrix, for the New York and Hong Kong stock exchanges. These properties are in agreement with the empirical ones. Our results quantitatively reveal that the multi-level herding is the microscopic generation mechanism of the sector structure, and provide new insight into the spatio-temporal interactions in financial systems at the microscopic level. PMID:25669427

Pollinator specialization: from the individual to the community.

PubMed

Brosi, Berry J

2016-06-01

1190 I. 1190 II. 1191 III. 1191 IV. 1193 V. 1193 1194 References 1194 SUMMARY: Most spermatophytes need conspecific pollen in order to produce seed. This need for specialization seems to conflict with the generalized nature of most plant-pollinator interactions. Specialization and generalization are dynamic - not fixed - and exist simultaneously in multiple states at different levels of biological hierarchy. Over the short term, specialization ensures conspecific pollen transfer, whereas over the long term, generalization improves system-level robustness. The balance between specialization and generalization at different scales is critical for different kinds of ecological functioning and is an important factor in plant speciation and the evolution of plant mating systems. Community context, including diversity and interaction network structure at different levels of aggregation, is a key driver of specialization dynamics. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Weakly Interacting Symmetric and Anti-Symmetric States in the Bilayer Systems

NASA Astrophysics Data System (ADS)

Marchewka, M.; Sheregii, E. M.; Tralle, I.; Tomaka, G.; Ploch, D.

We have studied the parallel magneto-transport in DQW-structures of two different potential shapes: quasi-rectangular and quasi-triangular. The quantum beats effect was observed in Shubnikov-de Haas (SdH) oscillations for both types of the DQW structures in perpendicular magnetic filed arrangement. We developed a special scheme for the Landau levels energies calculation by means of which we carried out the necessary simulations of beating effect. In order to obtain the agreement between our experimental data and the results of simulations, we introduced two different quasi-Fermi levels which characterize symmetric and anti-symmetric states in DQWs. The existence of two different quasi Fermi-Levels simply means, that one can treat two sub-systems (charge carriers characterized by symmetric and anti-symmetric wave functions) as weakly interacting and having their own rate of establishing the equilibrium state.

Pollen–pistil interactions and self-incompatibility in the Asteraceae: new insights from studies of Senecio squalidus (Oxford ragwort)

PubMed Central

Allen, Alexandra M.; Thorogood, Christopher J.; Hegarty, Matthew J.; Lexer, Christian; Hiscock, Simon J.

2011-01-01

Background Pollen–pistil interactions are an essential prelude to fertilization in angiosperms and determine compatibility/incompatibility. Pollen–pistil interactions have been studied at a molecular and cellular level in relatively few families. Self-incompatibility (SI) is the best understood pollen–pistil interaction at a molecular level where three different molecular mechanisms have been identified in just five families. Here we review studies of pollen–pistil interactions and SI in the Asteraceae, an important family that has been relatively understudied in these areas of reproductive biology. Scope We begin by describing the historical literature which first identified sporophytic SI (SSI) in species of Asteraceae, the SI system later identified and characterized at a molecular level in the Brassicaceae. Early structural and cytological studies in these two families suggested that pollen–pistil interactions and SSI were similar, if not the same. Recent cellular and molecular studies in Senecio squalidus (Oxford ragwort) have challenged this belief by revealing that despite sharing the same genetic system of SSI, the Brassicaceae and Asteraceae molecular mechanisms are different. Key cellular differences have also been highlighted in pollen–stigma interactions, which may arise as a consequence of the Asteraceae possessing a ‘semi-dry’ stigma, rather than the ‘dry’ stigma typical of the Brassicaceae. The review concludes with a summary of recent transcriptomic analyses aimed at identifying proteins regulating pollen–pistil interactions and SI in S. squalidus, and by implication the Asteraceae. The Senecio pistil transcriptome contains many novel pistil-specific genes, but also pistil-specific genes previously shown to play a role in pollen–pistil interactions in other species. Conclusions Studies in S. squalidus have shown that stigma structure and the molecular mechanism of SSI in the Asteraceae and Brassicaceae are different. The availability of a pool of pistil-specific genes for S. squalidus offers an opportunity to elucidate the molecular mechanisms of pollen–pistil interactions and SI in the Asteraceae. PMID:21752792

Multilevel Complex Networks and Systems

NASA Astrophysics Data System (ADS)

Caldarelli, Guido

2014-03-01

Network theory has been a powerful tool to model isolated complex systems. However, the classical approach does not take into account the interactions often present among different systems. Hence, the scientific community is nowadays concentrating the efforts on the foundations of new mathematical tools for understanding what happens when multiple networks interact. The case of economic and financial networks represents a paramount example of multilevel networks. In the case of trade, trade among countries the different levels can be described by the different granularity of the trading relations. Indeed, we have now data from the scale of consumers to that of the country level. In the case of financial institutions, we have a variety of levels at the same scale. For example one bank can appear in the interbank networks, ownership network and cds networks in which the same institution can take place. In both cases the systemically important vertices need to be determined by different procedures of centrality definition and community detection. In this talk I will present some specific cases of study related to these topics and present the regularities found. Acknowledged support from EU FET Project ``Multiplex'' 317532.

Request-Based Mediated Execution

ERIC Educational Resources Information Center

Sundresh, Sameer

2009-01-01

How do you dynamically customize the programming language available in a context within an existing system, without changing the underlying system? This dissertation introduces a language design approach that addresses this problem. The basic idea is to structure programs as systems of multiple interacting levels of abstraction, where all of the…

Emergence of long-range correlations and bursty activity patterns in online communication

NASA Astrophysics Data System (ADS)

Panzarasa, Pietro; Bonaventura, Moreno

2015-12-01

Research has suggested that the activity occurring in a variety of social, economic, and technological systems exhibits long-range fluctuations in time. Pronounced levels of rapidly occurring events are typically observed over short periods of time, followed by long periods of inactivity. Relatively few studies, however, have shed light on the degree to which inhomogeneous temporal processes can be detected at, and emerge from, different levels of analysis. Here we investigate patterns of human activity within an online forum in which communication can be assessed at three intertwined levels: the micro level of the individual users; the meso level of discussion groups and continuous sessions; and the macro level of the whole system. To uncover the relation between different levels, we conduct a number of numerical simulations of a zero-crossing model in which users' behavior is constrained by progressively richer and more realistic rules of social interaction. Results indicate that, when users are solipsistic, their bursty behavior is not sufficient for generating heavy-tailed interevent time distributions at a higher level. However, when users are socially interdependent, the power spectra and interevent time distributions of the simulated and real forums are remarkably similar at all levels of analysis. Social interaction is responsible for the aggregation of multiple bursty activities at the micro level into an emergent bursty activity pattern at a higher level. We discuss the implications of the findings for an emergentist account of burstiness in complex systems.

Combination of capecitabine and phenytoin may cause phenytoin intoxication: a case report.

PubMed

Ciftci, Rumeysa; Tas, Faruk; Karabulut, Senem; Ciftci, Serkan

2015-01-01

Capecitabine is an oral antineoplastic agent, and phenytoin is an anticonvulsant drug with a narrow therapeutic index. Although the interaction between capecitabine and phenytoin is rare, it may be potentially fatal. This interaction is thought to be at the level of CYP2C9 isoenzyme system in the liver. Here, we present a patient with metastatic breast cancer who developed phenytoin intoxication when using capecitabine and phenytoin together. Closely monitoring plasma phenytoin levels is essential if capecitabine is used with phenytoin concurrently.

Practical problems in controlling H5N1 high pathogenicity avian influenza at village level in Vietnam and introduction of biosecurity measures.

PubMed

Cristalli, Alessandro; Capua, Ilaria

2007-03-01

After a consultancy mission funded by a nongovernmental organization (NGO), information was collected on the dynamics of avian influenza (AI) infection at the rural level in a Vietnamese province with several ongoing outbreaks. AI outbreaks are frequent at village level due to environmental, ecological, agroecological, physical, social, and cultural factors, the underlying factor being poor hygienic conditions. Viral circulation is facilitated by the interactions of the integrated aquaculture, animal raising, horticulture agroecosystem, which relies in the peculiar integration of aquaculture (ponding), animal activities, and horticulture and by the connections with the live-bird market system. The interactions of these factors determine the complex system in which wild birds interact with domestic birds and in which people are constantly exposed to sources of infection, leading to the association between poverty and AI infection in humans. This experience underlines that despite all efforts by the Vietnamese Government, international institutions, and the NGO sector, awareness of AI at the village level needs to be improved. In turn, the leading institutions and international donors funding projects of technical cooperation aimed at tackling AI in Vietnam should invest in a system based on a deep knowledge of the practical problems of village condition to address AI with an effective approach. On the basis of the data collected during the mission, particularly on rural and semi-intensive poultry rearing systems, proposals that encompass the application of an effective vaccination strategy including backyard flocks coupled with dissemination of relevant information on biosecurity measures have been developed for decision makers.

Human-Computer Interaction and Virtual Environments

NASA Technical Reports Server (NTRS)

Noor, Ahmed K. (Compiler)

1995-01-01

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

The Social Neuroscience of Interpersonal Emotions.

PubMed

Müller-Pinzler, Laura; Krach, Sören; Krämer, Ulrike M; Paulus, Frieder M

In our daily lives, we constantly engage in reciprocal interactions with other individuals and represent ourselves in the context of our surrounding social world. Within social interactions, humans often experience interpersonal emotions such as embarrassment, shame, guilt, or pride. How interpersonal emotions are processed on the neural systems level is of major interest for social neuroscience research. While the configuration of laboratory settings in general is constraining for emotion research, recent neuroimaging investigations came up with new approaches to implement socially interactive and immersive scenarios for the real-life investigation of interpersonal emotions. These studies could show that among other brain regions the so-called mentalizing network, which is typically involved when we represent and make sense of others' states of mind, is associated with interpersonal emotions. The anterior insula/anterior cingulate cortex network at the same time processes one's own bodily arousal during such interpersonal emotional experiences. Current research aimed to explore how we make sense of others' emotional states during social interactions and investigates the modulating factors of our emotional experiences during social interactions. Understanding how interpersonal emotions are processed on the neural systems level may yield significant implications for neuropsychiatric disorders that affect social behavior such as social anxiety disorders or autism.

Increased signaling entropy in cancer requires the scale-free property of protein interaction networks.

PubMed

Teschendorff, Andrew E; Banerji, Christopher R S; Severini, Simone; Kuehn, Reimer; Sollich, Peter

2015-04-28

One of the key characteristics of cancer cells is an increased phenotypic plasticity, driven by underlying genetic and epigenetic perturbations. However, at a systems-level it is unclear how these perturbations give rise to the observed increased plasticity. Elucidating such systems-level principles is key for an improved understanding of cancer. Recently, it has been shown that signaling entropy, an overall measure of signaling pathway promiscuity, and computable from integrating a sample's gene expression profile with a protein interaction network, correlates with phenotypic plasticity and is increased in cancer compared to normal tissue. Here we develop a computational framework for studying the effects of network perturbations on signaling entropy. We demonstrate that the increased signaling entropy of cancer is driven by two factors: (i) the scale-free (or near scale-free) topology of the interaction network, and (ii) a subtle positive correlation between differential gene expression and node connectivity. Indeed, we show that if protein interaction networks were random graphs, described by Poisson degree distributions, that cancer would generally not exhibit an increased signaling entropy. In summary, this work exposes a deep connection between cancer, signaling entropy and interaction network topology.

High level theoretical study of benzene-halide adducts: the importance of C-H-anion hydrogen bonding.

PubMed

Coletti, Cecilia; Re, Nazzareno

2009-02-26

High level ab initio calculations were performed on the interaction of halide anions (F(-), Cl(-), Br(-), and I(-)) to benzene. For these systems recent experimental and theoretical data are rather scarce, in spite of their growingly acknowledged importance for binding in complex biological systems. We have thus explored the complete basis set limit and the effect of counterpoise basis set superposition error corrections on the minimum geometries and energies of benzene-halide adducts in their possible interaction modes. The binding energy and enthalpy values (ranging from -15.3 kcal/mol for fluoride to -6.1 kcal/mol for iodide) show that the hydrogen bonding occurring in these complexes cannot be described as a weak interaction. We have furthermore investigated the topology of the minima and of other selected sections of the potential energy surface, so to gain further insight on the nature of the halide-benzene interaction. In particular, the geometry corresponding to the C(6v) symmetry, although being overall repulsive, has displayed the unprecedented presence of a small flex (a minimum in C(6v) symmetry) with interaction energy close to zero or slightly attractive.

Increased signaling entropy in cancer requires the scale-free property of protein interaction networks

PubMed Central

Teschendorff, Andrew E.; Banerji, Christopher R. S.; Severini, Simone; Kuehn, Reimer; Sollich, Peter

2015-01-01

One of the key characteristics of cancer cells is an increased phenotypic plasticity, driven by underlying genetic and epigenetic perturbations. However, at a systems-level it is unclear how these perturbations give rise to the observed increased plasticity. Elucidating such systems-level principles is key for an improved understanding of cancer. Recently, it has been shown that signaling entropy, an overall measure of signaling pathway promiscuity, and computable from integrating a sample's gene expression profile with a protein interaction network, correlates with phenotypic plasticity and is increased in cancer compared to normal tissue. Here we develop a computational framework for studying the effects of network perturbations on signaling entropy. We demonstrate that the increased signaling entropy of cancer is driven by two factors: (i) the scale-free (or near scale-free) topology of the interaction network, and (ii) a subtle positive correlation between differential gene expression and node connectivity. Indeed, we show that if protein interaction networks were random graphs, described by Poisson degree distributions, that cancer would generally not exhibit an increased signaling entropy. In summary, this work exposes a deep connection between cancer, signaling entropy and interaction network topology. PMID:25919796

Hyperfine interaction in the Autler-Townes effect: The formation of bright, dark, and chameleon states

NASA Astrophysics Data System (ADS)

Kirova, T.; Cinins, A.; Efimov, D. K.; Bruvelis, M.; Miculis, K.; Bezuglov, N. N.; Auzinsh, M.; Ryabtsev, I. I.; Ekers, A.

2017-10-01

This paper is devoted to clarifying the implications of hyperfine (HF) interaction in the formation of adiabatic (i.e., "laser-dressed") states and their expression in the Autler-Townes (AT) spectra. We first use the Morris-Shore model [J. R. Morris and B. W. Shore, Phys. Rev. A 27, 906 (1983), 10.1103/PhysRevA.27.906] to illustrate how bright and dark states are formed in a simple reference system where closely spaced energy levels are coupled to a single state with a strong laser field with the respective Rabi frequency ΩS. We then expand the simulations to realistic hyperfine level systems in Na atoms for a more general case when non-negligible HF interaction can be treated as a perturbation in the total system Hamiltonian. A numerical analysis of the adiabatic states that are formed by coupling of the 3 p3 /2 and 4 d5 /2 states by the strong laser field and probed by a weak laser field on the 3 s1 /2-3 p3 /2 transition yielded two important conclusions. Firstly, the perturbation introduced by the HF interaction leads to the observation of what we term "chameleon" states—states that change their appearance in the AT spectrum, behaving as bright states at small to moderate ΩS, and fading from the spectrum similarly to dark states when ΩS is much larger than the HF splitting of the 3 p3 /2 state. Secondly, excitation by the probe field from two different HF levels of the ground state allows one to address orthogonal sets of adiabatic states; this enables, with appropriate choice of ΩS and the involved quantum states, a selective excitation of otherwise unresolved hyperfine levels in excited electronic states.

Preliminary Human Factors Design Guidelines For Driver Information Systems

DOT National Transportation Integrated Search

2001-01-01

During the summer and fall of 2000, a group of high level public safety and transportation officials was brought together by the US Department of Transportations (USDOT) Intelligent Transportation Systems (ITS) Program to consider the interaction bet...

Sig2BioPAX: Java tool for converting flat files to BioPAX Level 3 format.

PubMed

Webb, Ryan L; Ma'ayan, Avi

2011-03-21

The World Wide Web plays a critical role in enabling molecular, cell, systems and computational biologists to exchange, search, visualize, integrate, and analyze experimental data. Such efforts can be further enhanced through the development of semantic web concepts. The semantic web idea is to enable machines to understand data through the development of protocol free data exchange formats such as Resource Description Framework (RDF) and the Web Ontology Language (OWL). These standards provide formal descriptors of objects, object properties and their relationships within a specific knowledge domain. However, the overhead of converting datasets typically stored in data tables such as Excel, text or PDF into RDF or OWL formats is not trivial for non-specialists and as such produces a barrier to seamless data exchange between researchers, databases and analysis tools. This problem is particularly of importance in the field of network systems biology where biochemical interactions between genes and their protein products are abstracted to networks. For the purpose of converting biochemical interactions into the BioPAX format, which is the leading standard developed by the computational systems biology community, we developed an open-source command line tool that takes as input tabular data describing different types of molecular biochemical interactions. The tool converts such interactions into the BioPAX level 3 OWL format. We used the tool to convert several existing and new mammalian networks of protein interactions, signalling pathways, and transcriptional regulatory networks into BioPAX. Some of these networks were deposited into PathwayCommons, a repository for consolidating and organizing biochemical networks. The software tool Sig2BioPAX is a resource that enables experimental and computational systems biologists to contribute their identified networks and pathways of molecular interactions for integration and reuse with the rest of the research community.

Ideology and gender: observers' system justification and targets' gender as interactive predictors of citizenship expectations.

PubMed

Chiaburu, Dan S; Harris, T Brad; Smith, Troy A

2014-01-01

We integrate system justification and social role theory to explain how observers' system justification and target employees' gender interact to predict observers' expectations of targets' sportsmanship citizenship behaviors. In contrast with social role theory predictions, observers did not expect greater levels of sportsmanship from women compared to men. Yet observers expected more sportsmanship from women (a) when observers were ideologically motivated by gender-specific beliefs (gender-specific system justification; Study 1) and (b) when system justification was cued experimentally (Study 2). A heretofore-unexamined aspect, observers' ideology, modifies their expectations of sportsmanship citizenship across target genders. This has implications for system justification, social role, and organizational citizenship theoretical perspectives.

Ocean acidification alters the response of intertidal snails to a key sea star predator

PubMed Central

Jellison, Brittany M.; Ninokawa, Aaron T.; Hill, Tessa M.; Sanford, Eric; Gaylord, Brian

2016-01-01

Organism-level effects of ocean acidification (OA) are well recognized. Less understood are OA's consequences for ecological species interactions. Here, we examine a behaviourally mediated predator–prey interaction within the rocky intertidal zone of the temperate eastern Pacific Ocean, using it as a model system to explore OA's capacity to impair invertebrate anti-predator behaviours more broadly. Our system involves the iconic sea star predator, Pisaster ochraceus, that elicits flee responses in numerous gastropod prey. We examine, in particular, the capacity for OA-associated reductions in pH to alter flight behaviours of the black turban snail, Tegula funebralis, an often-abundant and well-studied grazer in the system. We assess interactions between these species at 16 discrete levels of pH, quantifying the full functional response of Tegula under present and near-future OA conditions. Results demonstrate the disruption of snail anti-predator behaviours at low pH, with decreases in the time individuals spend in refuge locations. We also show that fluctuations in pH, including those typical of rock pools inhabited by snails, do not materially change outcomes, implying little capacity for episodically benign pH conditions to aid behavioural recovery. Together, these findings suggest a strong potential for OA to induce cascading community-level shifts within this long-studied ecosystem. PMID:27358371

Mixing coarse-grained and fine-grained water in molecular dynamics simulations of a single system.

PubMed

Riniker, Sereina; van Gunsteren, Wilfred F

2012-07-28

The use of a supra-molecular coarse-grained (CG) model for liquid water as solvent in molecular dynamics simulations of biomolecules represented at the fine-grained (FG) atomic level of modelling may reduce the computational effort by one or two orders of magnitude. However, even if the pure FG model and the pure CG model represent the properties of the particular substance of interest rather well, their application in a hybrid FG/CG system containing varying ratios of FG versus CG particles is highly non-trivial, because it requires an appropriate balance between FG-FG, FG-CG, and CG-CG energies, and FG and CG entropies. Here, the properties of liquid water are used to calibrate the FG-CG interactions for the simple-point-charge water model at the FG level and a recently proposed supra-molecular water model at the CG level that represents five water molecules by one CG bead containing two interaction sites. Only two parameters are needed to reproduce different thermodynamic and dielectric properties of liquid water at physiological temperature and pressure for various mole fractions of CG water in FG water. The parametrisation strategy for the FG-CG interactions is simple and can be easily transferred to interactions between atomistic biomolecules and CG water.

Using interactive visual reasoning to support sense-making: implications for design.

PubMed

Kodagoda, Neesha; Attfield, Simon; Wong, B L William; Rooney, Chris; Choudhury, Sharmin Tinni

2013-12-01

This research aims to develop design guidelines for systems that support investigators and analysts in the exploration and assembly of evidence and inferences. We focus here on the problem of identifying candidate 'influencers' within a community of practice. To better understand this problem and its related cognitive and interaction needs, we conducted a user study using a system called INVISQUE (INteractive Visual Search and QUery Environment) loaded with content from the ACM Digital Library. INVISQUE supports search and manipulation of results over a freeform infinite 'canvas'. The study focuses on the representations user create and their reasoning process. It also draws on some pre-established theories and frameworks related to sense-making and cognitive work in general, which we apply as a 'theoretical lenses' to consider findings and articulate solutions. Analysing the user-study data in the light of these provides some understanding of how the high-level problem of identifying key players within a domain can translate into lower-level questions and interactions. This, in turn, has informed our understanding of representation and functionality needs at a level of description which abstracts away from the specifics of the problem at hand to the class of problems of interest. We consider the study outcomes from the perspective of implications for design.

The interaction between self-regulation and motivation prospectively predicting problem behavior in adolescence.

PubMed

Rhodes, Jessica D; Colder, Craig R; Trucco, Elisa M; Speidel, Carolyn; Hawk, Larry W; Lengua, Liliana J; Das Eiden, Rina; Wieczorek, William

2013-01-01

A large literature suggests associations between self-regulation and motivation and adolescent problem behavior; however, this research has mostly pitted these constructs against one another or tested them in isolation. Following recent neural-systems based theories (e.g., Ernst & Fudge, 2009 ), the present study investigated the interactions between self-regulation and approach and avoidance motivation prospectively predicting delinquency and depressive symptoms in early adolescence. The community sample included 387 adolescents aged 11 to 13 years old (55% female; 17% minority). Laboratory tasks were used to assess self-regulation and approach and avoidance motivation, and adolescent self-reports were used to measure depressive symptoms and delinquency. Analyses suggested that low levels of approach motivation were associated with high levels of depressive symptoms, but only at high levels of self-regulation (p = .01). High levels of approach were associated with high levels of rule breaking, but only at low levels of self-regulation (p < .05). These findings support contemporary neural-based systems theories that posit integration of motivational and self-regulatory individual differences via moderational models to understand adolescent problem behavior.

The Interaction Between Self-Regulation and Motivation Prospectively Predicting Problem Behavior in Adolescence

PubMed Central

Rhodes, Jessica D.; Colder, Craig R.; Trucco, Elisa M.; Speidel, Carolyn; Hawk, Larry W.; Lengua, Liliana J.; Eiden, Rina Das; Wiezcorek, William

2013-01-01

Objective A large literature suggests associations between self-regulation and motivation and adolescent problem behavior, however this research has mostly pitted these constructs against one another or tested them in isolation. Following recent neural-systems based theories (e.g., Ernst & Fudge, 2009), the present study investigated the interactions between self-regulation and approach and avoidance motivation prospectively predicting delinquency and depressive symptoms in early adolescence. Method The community sample included 387 adolescents aged 11–13 years old (55% female; 17% minority). Laboratory tasks were used to assess self-regulation and approach and avoidance motivation, and adolescent self-reports were used to measure depressive symptoms and delinquency. Results Analyses suggested that low levels of approach motivation were associated with high levels of depressive symptoms, but only at high levels of self-regulation (p = .01). High levels of approach were associated with high levels of rule breaking, but only at low levels of self-regulation (p < .05). Conclusions These findings support contemporary neural-based systems theories that posit integration of motivational and self-regulatory individual differences via moderational models to understand adolescent problem behavior. PMID:23477426

Untargeted metabolomics studies employing NMR and LC–MS reveal metabolic coupling between Nanoarcheum equitans and its archaeal host Ignicoccus hospitalis

DOE PAGES

Hamerly, Timothy; Tripet, Brian P.; Tigges, Michelle; ...

2014-11-05

Interactions between species are the basis of microbial community formation and infectious diseases. Systems biology enables the construction of complex models describing such interactions, leading to a better understanding of disease states and communities. However, before interactions between complex organisms can be understood, metabolic and energetic implications of simpler real-world host-microbe systems must be worked out. To this effect, untargeted metabolomics experiments were conducted and integrated with proteomics data to characterize key molecular-level interactions between two hyperthermophilic microbial species, both of which have reduced genomes. Metabolic changes and transfer of metabolites between the archaea Ignicoccus hospitalis and Nanoarcheum equitans weremore » investigated using integrated LC–MS and NMR metabolomics. The study of such a system is challenging, as no genetic tools are available, growth in the laboratory is challenging, and mechanisms by which they interact are unknown. Together with information about relative enzyme levels obtained from shotgun proteomics, the metabolomics data provided useful insights into metabolic pathways and cellular networks of I. hospitalis that are impacted by the presence of N. equitans, including arginine, isoleucine, and CTP biosynthesis. On the organismal level, the data indicate that N. equitans exploits metabolites generated by I. hospitalis to satisfy its own metabolic needs. Lastly, this finding is based on N. equitans’s consumption of a significant fraction of the metabolite pool in I. hospitalis that cannot solely be attributed to increased biomass production for N. equitans. Combining LC–MS and NMR metabolomics datasets improved coverage of the metabolome and enhanced the identification and quantitation of cellular metabolites.« less

Steady bipartite coherence induced by non-equilibrium environment

NASA Astrophysics Data System (ADS)

Huangfu, Yong; Jing, Jun

2018-01-01

We study the steady state of two coupled two-level atoms interacting with a non-equilibrium environment that consists of two heat baths at different temperatures. Specifically, we analyze four cases with respect to the configuration about the interactions between atoms and heat baths. Using secular approximation, the conventional master equation usually neglects steady-state coherence, even when the system is coupled with a non-equilibrium environment. When employing the master equation with no secular approximation, we find that the system coherence in our model, denoted by the off-diagonal terms in the reduced density matrix spanned by the eigenvectors of the system Hamiltonian, would survive after a long-time decoherence evolution. The absolute value of residual coherence in the system relies on different configurations of interaction channels between the system and the heat baths. We find that a large steady quantum coherence term can be achieved when the two atoms are resonant. The absolute value of quantum coherence decreases in the presence of additional atom-bath interaction channels. Our work sheds new light on the mechanism of steady-state coherence in microscopic quantum systems in non-equilibrium environments.

Active vision in satellite scene analysis

NASA Technical Reports Server (NTRS)

Naillon, Martine

1994-01-01

In earth observation or planetary exploration it is necessary to have more and, more autonomous systems, able to adapt to unpredictable situations. This imposes the use, in artificial systems, of new concepts in cognition, based on the fact that perception should not be separated from recognition and decision making levels. This means that low level signal processing (perception level) should interact with symbolic and high level processing (decision level). This paper is going to describe the new concept of active vision, implemented in Distributed Artificial Intelligence by Dassault Aviation following a 'structuralist' principle. An application to spatial image interpretation is given, oriented toward flexible robotics.

To delegate or not to delegate: A review of control frameworks for autonomous cars.

PubMed

Richards, Dale; Stedmon, Alex

2016-03-01

There have been significant advances in technology and automated systems that will eventually see the use of autonomous cars as commonplace on our roads. Various systems are already available that provide the driver with different levels of decision support. This paper highlights the key human factors issues associated with the interaction between the user and an autonomous system, including assistive decision support and the delegation of authority to the automobile. The level of support offered to the driver can range from traditional automated assistance, to system generated guidance that offers advice for the driver to act upon, and even more direct action that is initiated by the system itself without driver intervention. In many of these instances the role of the driver is slowly moving towards a supervisory role within a complex system rather than one of direct control of the vehicle. Different paradigms of interaction are considered and focus is placed on the partnership that takes place between the driver and the vehicle. Drawing on the wealth of knowledge that exists within the aviation domain and research literature that examines technology partnerships within the cockpit, this paper considers important factors that will assist the automotive community to understand the underlying issues of the human and their interaction within complex systems. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A Study on the Surface and Subsurface Water Interaction Based on the Groundwater Recession Curve

NASA Astrophysics Data System (ADS)

Wang, S. T.; Chen, Y. W.; Chang, L. C.; Chiang, C. J.; Wang, Y. S.

2017-12-01

The interaction of surface to subsurface water is an important issue for groundwater resources assessment and management. The influences of surface water to groundwater are mainly through the rainfall recharge, river recharge and discharge and other boundary sources. During a drought period, the interaction of river and groundwater may be one of the main sources of groundwater level recession. Therefore, this study explores the interaction of surface water to groundwater via the groundwater recession. During drought periods, the pumping and river interaction together are the main mechanisms causing the recession of groundwater level. In principle, larger gradient of the recession curve indicates more groundwater discharge and it is an important characteristic of the groundwater system. In this study, to avoid time-consuming manual analysis, the Python programming language is used to develop a statistical analysis model for exploring the groundwater recession information. First, the slopes of the groundwater level hydrograph at every time step were computed for each well. Then, for each well, the represented slope to each groundwater level was defined as the slope with 90% exceedance probability. The relationship between the recession slope and the groundwater level can then be obtained. The developed model is applied to Choushui River Alluvial Fan. In most wells, the results show strong positive correlations between the groundwater levels and the absolute values of the recession slopes.

Analysis of protein interactions within the cytokinin-signaling pathway of Arabidopsis thaliana.

PubMed

Dortay, Hakan; Mehnert, Nijuscha; Bürkle, Lukas; Schmülling, Thomas; Heyl, Alexander

2006-10-01

The signal of the plant hormone cytokinin is perceived by membrane-located sensor histidine kinases and transduced by other members of the plant two-component system. In Arabidopsis thaliana, 28 two-component system proteins (phosphotransmitters and response regulators) act downstream of three receptors, transmitting the signal from the membrane to the nucleus and modulating the cellular response. Although the principal signaling mechanism has been elucidated, redundancy in the system has made it difficult to understand which of the many components interact to control the downstream biological processes. Here, we present a large-scale interaction study comprising most members of the Arabidopsis cytokinin signaling pathway. Using the yeast two-hybrid system, we detected 42 new interactions, of which more than 90% were confirmed by in vitro coaffinity purification. There are distinct patterns of interaction between protein families, but only a few interactions between proteins of the same family. An interaction map of this signaling pathway shows the Arabidopsis histidine phosphotransfer proteins as hubs, which interact with members from all other protein families, mostly in a redundant fashion. Domain-mapping experiments revealed the interaction domains of the proteins of this pathway. Analyses of Arabidopsis histidine phosphotransfer protein 5 mutant proteins showed that the presence of the canonical phospho-accepting histidine residue is not required for the interactions. Interaction of A-type response regulators with Arabidopsis histidine phosphotransfer proteins but not with B-type response regulators suggests that their known activity in feedback regulation may be realized by interfering at the level of Arabidopsis histidine phosphotransfer protein-mediated signaling. This study contributes to our understanding of the protein interactions of the cytokinin-signaling system and provides a framework for further functional studies in planta.

Bispectral pairwise interacting source analysis for identifying systems of cross-frequency interacting brain sources from electroencephalographic or magnetoencephalographic signals

NASA Astrophysics Data System (ADS)

Chella, Federico; Pizzella, Vittorio; Zappasodi, Filippo; Nolte, Guido; Marzetti, Laura

2016-05-01

Brain cognitive functions arise through the coordinated activity of several brain regions, which actually form complex dynamical systems operating at multiple frequencies. These systems often consist of interacting subsystems, whose characterization is of importance for a complete understanding of the brain interaction processes. To address this issue, we present a technique, namely the bispectral pairwise interacting source analysis (biPISA), for analyzing systems of cross-frequency interacting brain sources when multichannel electroencephalographic (EEG) or magnetoencephalographic (MEG) data are available. Specifically, the biPISA makes it possible to identify one or many subsystems of cross-frequency interacting sources by decomposing the antisymmetric components of the cross-bispectra between EEG or MEG signals, based on the assumption that interactions are pairwise. Thanks to the properties of the antisymmetric components of the cross-bispectra, biPISA is also robust to spurious interactions arising from mixing artifacts, i.e., volume conduction or field spread, which always affect EEG or MEG functional connectivity estimates. This method is an extension of the pairwise interacting source analysis (PISA), which was originally introduced for investigating interactions at the same frequency, to the study of cross-frequency interactions. The effectiveness of this approach is demonstrated in simulations for up to three interacting source pairs and for real MEG recordings of spontaneous brain activity. Simulations show that the performances of biPISA in estimating the phase difference between the interacting sources are affected by the increasing level of noise rather than by the number of the interacting subsystems. The analysis of real MEG data reveals an interaction between two pairs of sources of central mu and beta rhythms, localizing in the proximity of the left and right central sulci.

Design for interaction between humans and intelligent systems during real-time fault management

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Schreckenghost, Debra L.; Thronesbery, Carroll G.

1992-01-01

Initial results are reported to provide guidance and assistance for designers of intelligent systems and their human interfaces. The objective is to achieve more effective human-computer interaction (HCI) for real time fault management support systems. Studies of the development of intelligent fault management systems within NASA have resulted in a new perspective of the user. If the user is viewed as one of the subsystems in a heterogeneous, distributed system, system design becomes the design of a flexible architecture for accomplishing system tasks with both human and computer agents. HCI requirements and design should be distinguished from user interface (displays and controls) requirements and design. Effective HCI design for multi-agent systems requires explicit identification of activities and information that support coordination and communication between agents. The effects are characterized of HCI design on overall system design and approaches are identified to addressing HCI requirements in system design. The results include definition of (1) guidance based on information level requirements analysis of HCI, (2) high level requirements for a design methodology that integrates the HCI perspective into system design, and (3) requirements for embedding HCI design tools into intelligent system development environments.

A systems biology perspective on plant-microbe interactions: biochemical and structural targets of pathogen effectors.

PubMed

Pritchard, Leighton; Birch, Paul

2011-04-01

Plants have biochemical defences against stresses from predators, parasites and pathogens. In this review we discuss the interaction of plant defences with microbial pathogens such as bacteria, fungi and oomycetes, and viruses. We examine principles of complex dynamic networks that allow identification of network components that are differentially and predictably sensitive to perturbation, thus making them likely effector targets. We relate these principles to recent developments in our understanding of known effector targets in plant-pathogen systems, and propose a systems-level framework for the interpretation and modelling of host-microbe interactions mediated by effectors. We describe this framework briefly, and conclude by discussing useful experimental approaches for populating this framework. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

A post-Bertalanffy Systemics Healthcare Competitive Framework Proposal.

PubMed

Fiorini, Rodolfo A; Santacroce, Giulia F

2014-01-01

Health Information community can take advantage of a new evolutive categorization cybernetic framework. A systemic concept of principles organizing nature is proposed. It can be used as a multiscaling reference framework to develop successful and competitive antifragile system and new HRO information management strategies in advanced healthcare organization (HO) and high reliability organization (HRO) conveniently. Expected impacts are multifarious and quite articulated at different system scale level: major one is that, for the first time, Biomedical Engineering ideal system categorization levels can be matched exactly to practical system modeling interaction styles, with no paradigmatic operational ambiguity and information loss.

Systems Biology for Organotypic Cell Cultures

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

Grego, Sonia; Dougherty, Edward R.; Alexander, Francis J.

Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, “organotypic” cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomicmore » data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data. This consensus report summarizes the discussions held.« less

Workshop Report: Systems Biology for Organotypic Cell Cultures

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

Grego, Sonia; Dougherty, Edward R.; Alexander, Francis Joseph

Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, “organotypic” cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomicmore » data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data.« less

Workshop Report: Systems Biology for Organotypic Cell Cultures

DOE PAGES

Grego, Sonia; Dougherty, Edward R.; Alexander, Francis Joseph; ...

2016-11-14

Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, “organotypic” cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomicmore » data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data.« less

Systems biology for organotypic cell cultures.

PubMed

Grego, Sonia; Dougherty, Edward R; Alexander, Francis J; Auerbach, Scott S; Berridge, Brian R; Bittner, Michael L; Casey, Warren; Cooley, Philip C; Dash, Ajit; Ferguson, Stephen S; Fennell, Timothy R; Hawkins, Brian T; Hickey, Anthony J; Kleensang, Andre; Liebman, Michael N J; Martin, Florian; Maull, Elizabeth A; Paragas, Jason; Qiao, Guilin Gary; Ramaiahgari, Sreenivasa; Sumner, Susan J; Yoon, Miyoung

2017-01-01

Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, "organotypic" cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomic data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data.

Study of ultrasonic attenuation in f-electron systems in the paramagnetic limit of Coulomb interaction

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

Shadangi, Asit Ku., E-mail: asitshad@iopb.res.in; Rout, G. C., E-mail: gcr@iopb.res.in

2015-05-15

We report here a microscopic model study of ultrasonic attenuation in f-electron systems based on Periodic Anderson Model in which Coulomb interaction is considered within a mean-field approximation for a weak interaction. The Phonon is coupled to the conduction band and f-electrons. The phonon Green's function is calculated by Zubarev's technique of the Green's function method. The temperature dependent ultrasonic attenuation co-efficient is calculated from the imaginary part of the phonon self-energy in the dynamic and long wave length limit. The f-electron occupation number is calculated self-consistently in paramagnetic limit of Coulomb interaction. The effect of the Coulomb interaction onmore » ultrasonic attenuation is studied by varying the phonon coupling parameters to the conduction and f-electrons, hybridization strength, the position of f-level and the Coulomb interaction Strength. Results are discussed on the basis of experimental results.« less

An interactive approach based on a discrete differential evolution algorithm for a class of integer bilevel programming problems

NASA Astrophysics Data System (ADS)

Li, Hong; Zhang, Li; Jiao, Yong-Chang

2016-07-01

This paper presents an interactive approach based on a discrete differential evolution algorithm to solve a class of integer bilevel programming problems, in which integer decision variables are controlled by an upper-level decision maker and real-value or continuous decision variables are controlled by a lower-level decision maker. Using the Karush--Kuhn-Tucker optimality conditions in the lower-level programming, the original discrete bilevel formulation can be converted into a discrete single-level nonlinear programming problem with the complementarity constraints, and then the smoothing technique is applied to deal with the complementarity constraints. Finally, a discrete single-level nonlinear programming problem is obtained, and solved by an interactive approach. In each iteration, for each given upper-level discrete variable, a system of nonlinear equations including the lower-level variables and Lagrange multipliers is solved first, and then a discrete nonlinear programming problem only with inequality constraints is handled by using a discrete differential evolution algorithm. Simulation results show the effectiveness of the proposed approach.

Therapy for Family Systems.

ERIC Educational Resources Information Center

Rosmann, Michael R.

A family therapy model, based on a conceptualization of the family as a behavioral system whose members interact adaptively so that an optimal level of functioning is maintained within the system, is described. The divergent roots of this conceptualization are discussed briefly, as are the treatment approaches based on it. The author's model,…

Automated Interactive Storeroom Inventory System.

ERIC Educational Resources Information Center

Sapp, Albert L.; Hess, Larry G.

1989-01-01

The inventory system designed for six storerooms in three buildings at the University of Illinois at Urbana-Champaign's School of Chemical Sciences replaced an issue-slip and transactions record system with barcode technology. Data collection error reductions have been significant, making it easier to determine stock levels and plan purchases.…

Marital Conflict and Growth in Children's Internalizing Symptoms: The Role of Autonomic Nervous System Activity

ERIC Educational Resources Information Center

El-Sheikh, Mona; Keiley, Margaret; Erath, Stephen; Dyer, W. Justin

2013-01-01

We assessed trajectories of children's internalizing symptoms, indexed through anxiety and depression, with a focus on the role of interactions between interparental marital conflict, children's sympathetic nervous system activity indexed by skin conductance level (SCL), and parasympathetic nervous system activity indexed by respiratory sinus…

An Assessment of Students' Understanding of Ecosystem Concepts: Conflating Ecological Systems and Cycles

ERIC Educational Resources Information Center

Jordan, Rebecca; Gray, Steven; Demeter, Marylee; Lui, Lei; Hmelo-Silver, Cindy E.

2009-01-01

Teaching ecological concepts in schools is important in promoting natural science and environmental education for young learners. Developing educational programs is difficult, however, because of complicated ecological processes operating on multiple levels, the unlimited nature of potential system interactions (given the openness of systems), and…

The Social System in Outdoor Adventure Education Programs

ERIC Educational Resources Information Center

Sibthorp, Jim; Jostad, Jeremy

2014-01-01

Many components of the social system interact with one another to produce group-level behavior that determines the functionality of the small group in outdoor adventure education (OAE). This article synthesizes the contemporary literature and theory regarding eight aspects of the OAE social system: (a) Macro Contextual Factors, (b) Student…

Ecological Issues Related to Children's Health and Safety

ERIC Educational Resources Information Center

Aldridge, Jerry; Kohler, Maxie

2009-01-01

Issues concerning the health and safety of children and youth occur at multiple levels. Bronfenbrenner (1995) proposed an ecological systems approach in which multiple systems interact to enhance or diminish children's development. The same systems are at work in health promotion. The authors present and review articles that reflect the multiple…

Predator and prey activity levels jointly influence the outcome of long-term foraging bouts

PubMed Central

2013-01-01

Consistent interindividual differences in behavior (i.e., “behavioral types”) may be a key factor in determining the outcome of species interactions. Studies that simultaneously account for the behavioral types of individuals in multiple interacting species, such as predator–prey systems, may be particularly strong predictors of ecological outcomes. Here, we test the predator–prey locomotor crossover hypothesis, which predicts that active predators are more likely to encounter and consume prey with the opposing locomotor tendency. We test this hypothesis using intraspecific behavioral variation in both a predator and prey species as predictors of foraging outcomes. We use the old field jumping spider, Phidippus clarus (Araneae, Salticidae), and the house cricket, Acheta domesticus (Orthoptera, Gryllidae), as a model predator–prey system in laboratory mesocosm trials. Stable individual differences in locomotor tendencies were identified in both P. clarus and A. domesticus, and the outcome of foraging bouts depended neither on the average activity level of the predator nor on the average activity level of prey. Instead, an interaction between the activity level of spiders and crickets predicted spider foraging success and prey survivorship. Consistent with the locomotor crossover hypothesis, predators exhibiting higher activity levels consumed more prey when in an environment containing low-activity prey items and vice versa. This study highlights 1) the importance of intraspecific variation in determining the outcome of predator–prey interactions and 2) that acknowledging behavioral variation in only a single species may be insufficient to characterize the performance consequences of intraspecific trait variants. PMID:23935257

Observation of Mollow Triplets with Tunable Interactions in Double Lambda Systems of Individual Hole Spins

NASA Astrophysics Data System (ADS)

Lagoudakis, K. G.; Fischer, K. A.; Sarmiento, T.; McMahon, P. L.; Radulaski, M.; Zhang, J. L.; Kelaita, Y.; Dory, C.; Müller, K.; Vučković, J.

2017-01-01

Although individual spins in quantum dots have been studied extensively as qubits, their investigation under strong resonant driving in the scope of accessing Mollow physics is still an open question. Here, we have grown high quality positively charged quantum dots embedded in a planar microcavity that enable enhanced light-matter interactions. Under a strong magnetic field in the Voigt configuration, individual positively charged quantum dots provide a double lambda level structure. Using a combination of above-band and resonant excitation, we observe the formation of Mollow triplets on all optical transitions. We find that when the strong resonant drive power is used to tune the Mollow-triplet lines through each other, we observe anticrossings. We also demonstrate that the interaction that gives rise to the anticrossings can be controlled in strength by tuning the polarization of the resonant laser drive. Quantum-optical modeling of our system fully captures the experimentally observed spectra and provides insight on the complicated level structure that results from the strong driving of the double lambda system.

Computer simulation of surface and film processes

NASA Technical Reports Server (NTRS)

Tiller, W. A.; Halicioglu, M. T.

1983-01-01

Adequate computer methods, based on interactions between discrete particles, provide information leading to an atomic level understanding of various physical processes. The success of these simulation methods, however, is related to the accuracy of the potential energy function representing the interactions among the particles. The development of a potential energy function for crystalline SiO2 forms that can be employed in lengthy computer modelling procedures was investigated. In many of the simulation methods which deal with discrete particles, semiempirical two body potentials were employed to analyze energy and structure related properties of the system. Many body interactions are required for a proper representation of the total energy for many systems. Many body interactions for simulations based on discrete particles are discussed.

Coastal system mapping: a new approach to formalising and conceptualising the connectivity of large-scale coastal systems

NASA Astrophysics Data System (ADS)

French, J.; Burningham, H.; Whitehouse, R.

2010-12-01

The concept of the coastal sediment cell has proved invaluable as a basis for estimating sediment budgets and as a framework for coastal management. However, whilst coastal sediment cells are readily identified on compartmentalised coastlines dominated by beach-grade material, the cell concept is less suited to handling broader linkages between estuarine, coastal and offshore systems, and for incorporating longer-range suspended sediment transport. We present a new approach to the conceptualisation of large-scale coastal geomorphic systems based on a hierarchical classification of component landforms and management interventions and mapping of the interactions between them. Coastal system mapping is founded on a classification that identifies high-level landform features, low-level landform elements and engineering interventions. Geomorphic features define the large-scale organisation of a system and include landforms that define gross coastal configuration (e.g. headland, bay) as well as fluvial, estuarine and offshore sub-systems that exchange sediment with and influence the open coast. Detailed system structure is mapped out with reference to a larger set of geomorphic elements (e.g. cliff, dune, beach ridge). Element-element interactions define cross-shore linkages (conceptualised as hinterland, backshore and foreshore zones) and alongshore system structure. Both structural and non-structural engineering interventions are also represented at this level. Element-level mapping is rationalised to represent alongshore variation using as few elements as possible. System linkages include both sediment transfer pathways and influences not associated with direct mass transfer (e.g. effect of a jetty at an inlet). A formal procedure for capturing and graphically representing coastal system structure has been developed around free concept mapping software, CmapTools (http://cmap.ihmc.us). Appended meta-data allow geographic coordinates, data, images and literature pertaining to specific locations to be embedded in system maps. Exported maps can be analysed separately to quantify abundance of system components and their scales of interaction. Our approach is demonstrated for different scales and geomorphic contexts in the UK, including Alnmouth Bay (NE England; 15km), Lowestoft to Felixstowe (E England; 73km) and Cardigan Bay (Wales; 267km). Aerial imagery provides the primary basis for identifying features and elements and likely modes of interaction. This interpretation is then checked against relevant research literature and site data. Coastal system mapping is a kind of knowledge formalisation that generalises disparate sources of information (‘plain data’) into usable knowledge. Consensus-derived system maps are highly effective as a catalyst for structured discussion of geomorphic system behaviour and its implications for coastal management. They also function as a repository for results from quantitative analyses and modelling.

Coming to Understand Diversity and Education: Life Experiences and Educational Opportunities

ERIC Educational Resources Information Center

Chamberlain, Steven Paul

2015-01-01

Coming to understand how cultural differences influence interactions between educators and students and their parents is a complex and perhaps life-long discovery. Culture helps to define groups' belief systems and expectations for appropriate behavior, often at a hidden level. Pre-service teachers need multiple opportunities to interact with…

Exactly soluble model of the time-resolved fluorescence return to thermal equilibrium in many-particle systems after excitation

NASA Astrophysics Data System (ADS)

Czachor, Andrzej

2016-02-01

In this paper we consider the assembly of weakly interacting identical particles, where the occupation of single-particle energy-levels at thermal equilibrium is governed by statistics. The analytic form of the inter-energy-level jump matrix is derived and analytic solution of the related eigen-problem is given. It allows one to demonstrate the nature of decline in time of the energy emission (fluorescence, recombination) of such many-level system after excitation in a relatively simple and unifying way - as a multi-exponential de-excitation. For the system of L energy levels the number of the de-excitation lifetimes is L-1. The lifetimes depend on the energy level spectrum as a whole. Two- and three-level systems are considered in detail. The impact of the energy level degeneracy on the lifetimes is discussed.

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

Liu, Jianguo; Hull, Vanessa; Batistella, Mateus

Interactions between distant places are increasingly widespread and influential, often leading to unexpected outcomes with profound implications for sustainability. Numerous sustainability studies have been conducted within a particular place with little attention to the impacts of distant interactions on sustainability in multiple places. Although distant forces have been studied, they are usually treated as exogenous variables and feedbacks have been rarely considered. To understand and integrate various distant interactions better, we propose an integrated framework based on telecoupling – an umbrella concept that refers to socioeconomic and environmental interactions over distances. The concept of telecoupling is a logical extension ofmore » research on coupled human and natural systems, in which human and natural systems interact within particular places. The telecoupling framework contains five major interrelated components (coupled human and natural systems, agents, flows, causes, and effects). We illustrate the framework using two examples of distant interactions, highlight the implications of the framework, and discuss research needs and approaches to move research on telecouplings forward. The framework can help better analyze system components and their interrelationships, identify research gaps, detect hidden costs and untapped benefits, provide a useful means to incorporate feedbacks as well as trade-offs and synergies across multiple places (sending, receiving, and spillover systems), and improve the understanding of distant interactions and the effectiveness of policies for socioeconomic and environmental sustainability from local to global levels.« less

Reproduction and the renin-angiotensin system

NASA Technical Reports Server (NTRS)

Ganong, W. F.

1995-01-01

A unique aspect of the circulating renin-angiotensin system and the many independent tissue renin-angiotensin systems is their interactions at multiple levels with reproduction. These interactions, which have received relatively little attention, include effects of estrogens and possibly androgens on hepatic and renal angiotensinogen mRNA; effects of androgens on the Ren-2 gene and salivary renin in mice; the prorenin surge that occurs with but outlasts the LH surge during the menstrual cycle; the inhibitory effects of estrogens on thirst and water intake; the tissue renin-angiotensin systems in the brain, the anterior pituitary, and the ovaries and testes, that is, in all the components of the hypothalamo-pituitary-gonadal axis; the presence of some components of the renin-angiotensin system in the uterus and the fetoplacental unit; and the possible relation of renin and angiotensin to ovulation and fetal well-being. These interactions are described and their significance considered in this short review.

The role of idiotypic interactions in the adaptive immune system: a belief-propagation approach

NASA Astrophysics Data System (ADS)

Bartolucci, Silvia; Mozeika, Alexander; Annibale, Alessia

2016-08-01

In this work we use belief-propagation techniques to study the equilibrium behaviour of a minimal model for the immune system comprising interacting T and B clones. We investigate the effect of the so-called idiotypic interactions among complementary B clones on the system’s activation. Our results show that B-B interactions increase the system’s resilience to noise, making clonal activation more stable, while increasing the cross-talk between different clones. We derive analytically the noise level at which a B clone gets activated, in the absence of cross-talk, and find that this increases with the strength of idiotypic interactions and with the number of T cells sending signals to the B clones. We also derive, analytically and numerically, via population dynamics, the critical line where clonal cross-talk arises. Our approach allows us to derive the B clone size distribution, which can be experimentally measured and gives important information about the adaptive immune system response to antigens and vaccination.

Bodily systems and the spatial-functional structure of the human body.

PubMed

Smith, Barry; Munn, Katherine; Papakin, Igor

2004-01-01

The human body is a system made of systems. The body is divided into bodily systems proper, such as the endocrine and circulatory systems, which are subdivided into many sub-systems at a variety of levels, whereby all systems and subsystems engage in massive causal interaction with each other and with their surrounding environments. Here we offer an explicit definition of bodily system and provide a framework for understanding their causal interactions. Medical sciences provide at best informal accounts of basic notions such as system, process, and function, and while such informality is acceptable in documentation created for human beings, it falls short of what is needed for computer representations. In our analysis we will accordingly provide the framework for a formal definition of bodily system and of associated notions.

Light-Nuclei Spectra from Chiral Dynamics

NASA Astrophysics Data System (ADS)

Piarulli, M.; Baroni, A.; Girlanda, L.; Kievsky, A.; Lovato, A.; Lusk, Ewing; Marcucci, L. E.; Pieper, Steven C.; Schiavilla, R.; Viviani, M.; Wiringa, R. B.

2018-02-01

In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels and level ordering of nuclei in the mass range A =4 - 12 , accurate to ≤2 % of the binding energy, in very satisfactory agreement with experimental data.

Effect of reaction control system jet-flow field interactions on a 0.015 scale model space shuttle orbiter aerodynamic characteristics

NASA Technical Reports Server (NTRS)

Monta, W. J.; Rausch, J. R.

1973-01-01

The effects of the reaction control system (RCS) jet-flow field interactions on the space shuttle orbiter system during entry are discussed. The primary objective of the test program was to obtain data for the shuttle orbiter configuration to determine control amplification factors resulting from jet interaction between the RCS plumes and the external flow over the vehicle. A secondary objective was to provide data for comparison and improvement of analytic jet interaction prediction techniques. The test program was divided into two phases; (1) force and moment measurements were made with and without RCS blowing, investigating environment parameters (R sub e, Alpha, Beta), RCS plume parameters (Jet pressure ratio, momentum ratio and thrust level), and geometry parameters (RCS pod locations) on the orbiter model, (2) oil flow visualization tests were conducted on a dummy balance at the end of the test.

Identification of water quality management policy of watershed system with multiple uncertain interactions using a multi-level-factorial risk-inference-based possibilistic-probabilistic programming approach.

PubMed

Liu, Jing; Li, Yongping; Huang, Guohe; Fu, Haiyan; Zhang, Junlong; Cheng, Guanhui

2017-06-01

In this study, a multi-level-factorial risk-inference-based possibilistic-probabilistic programming (MRPP) method is proposed for supporting water quality management under multiple uncertainties. The MRPP method can handle uncertainties expressed as fuzzy-random-boundary intervals, probability distributions, and interval numbers, and analyze the effects of uncertainties as well as their interactions on modeling outputs. It is applied to plan water quality management in the Xiangxihe watershed. Results reveal that a lower probability of satisfying the objective function (θ) as well as a higher probability of violating environmental constraints (q i ) would correspond to a higher system benefit with an increased risk of violating system feasibility. Chemical plants are the major contributors to biological oxygen demand (BOD) and total phosphorus (TP) discharges; total nitrogen (TN) would be mainly discharged by crop farming. It is also discovered that optimistic decision makers should pay more attention to the interactions between chemical plant and water supply, while decision makers who possess a risk-averse attitude would focus on the interactive effect of q i and benefit of water supply. The findings can help enhance the model's applicability and identify a suitable water quality management policy for environmental sustainability according to the practical situations.

Toward a framework for levels of robot autonomy in human-robot interaction.

PubMed

Beer, Jenay M; Fisk, Arthur D; Rogers, Wendy A

2014-07-01

A critical construct related to human-robot interaction (HRI) is autonomy, which varies widely across robot platforms. Levels of robot autonomy (LORA), ranging from teleoperation to fully autonomous systems, influence the way in which humans and robots may interact with one another. Thus, there is a need to understand HRI by identifying variables that influence - and are influenced by - robot autonomy. Our overarching goal is to develop a framework for levels of robot autonomy in HRI. To reach this goal, the framework draws links between HRI and human-automation interaction, a field with a long history of studying and understanding human-related variables. The construct of autonomy is reviewed and redefined within the context of HRI. Additionally, the framework proposes a process for determining a robot's autonomy level, by categorizing autonomy along a 10-point taxonomy. The framework is intended to be treated as guidelines to determine autonomy, categorize the LORA along a qualitative taxonomy, and consider which HRI variables (e.g., acceptance, situation awareness, reliability) may be influenced by the LORA.

Toward a framework for levels of robot autonomy in human-robot interaction

PubMed Central

Beer, Jenay M.; Fisk, Arthur D.; Rogers, Wendy A.

2017-01-01

A critical construct related to human-robot interaction (HRI) is autonomy, which varies widely across robot platforms. Levels of robot autonomy (LORA), ranging from teleoperation to fully autonomous systems, influence the way in which humans and robots may interact with one another. Thus, there is a need to understand HRI by identifying variables that influence – and are influenced by – robot autonomy. Our overarching goal is to develop a framework for levels of robot autonomy in HRI. To reach this goal, the framework draws links between HRI and human-automation interaction, a field with a long history of studying and understanding human-related variables. The construct of autonomy is reviewed and redefined within the context of HRI. Additionally, the framework proposes a process for determining a robot’s autonomy level, by categorizing autonomy along a 10-point taxonomy. The framework is intended to be treated as guidelines to determine autonomy, categorize the LORA along a qualitative taxonomy, and consider which HRI variables (e.g., acceptance, situation awareness, reliability) may be influenced by the LORA. PMID:29082107

A theoretical study of complexes formed between cations and curved aromatic systems: electrostatics does not always control cation-π interaction.

PubMed

Carrazana-García, Jorge A; Cabaleiro-Lago, Enrique M; Rodríguez-Otero, Jesús

2017-04-19

The present work studies the interaction of two extended curved π-systems (corannulene and sumanene) with various cations (sodium, potassium, ammonium, tetramethylammonium, guanidinium and imidazolium). Polyatomic cations are models of groups found in important biomolecules in which cation-π interaction plays a fundamental role. The results indicate an important size effect: with extended π systems and cations of the size of potassium and larger, dispersion is much more important than has been generally recognized for cation-π interactions. In most of the systems studied here, the stability of the cation-π complexes is the result of a balanced combination of electrostatic, induction and dispersion contributions. None of the systems studied here owes its stability to the electrostatic interaction more than 42%. Induction dominates stabilization in complexes with sodium, and in some of the potassium and ammonium complexes. In complexes with large cations and with flat cations dispersion is the major stabilizing contribution and can provide more than 50% of the stabilization energy. This implies that theoretical studies of the cation-π interaction involving large or even medium-size fragments require a level of calculation capable of properly modelling dispersion. The separation between the cation and the π system is another important factor to take into account, especially when the fragments of the cation-π complex are bound (for example, to a protein backbone) and cannot interact at the most favourable distance.

Land Sea Level Difference Impacts on Socio-Hydrological System.

NASA Astrophysics Data System (ADS)

Sung, K.; Yu, D. J.; Oh, W. S.; Sangwan, N.

2016-12-01

Allowing moderate shocks can be a new solution that helps to build adaptive capacity in society is a rising issue. In Social-Ecological field, Carpenter et al. (2015) suggested that exposure to short-term variability leads to long term resilience by enlarging safe operating space (SOS). The SOS refers to the boundary of favorable state that ecosystem can maintain resilience without imposing certain conditions (Carpenter et al. 2015). Our work is motivated by defining SOS in socio-hydrological system(SHS) because it can be an alternative way for flood management beyond optimized or robust flood control. In this context, large flood events that make system to cross the SOS should be fully managed, but frequent small floods need to be allowed if the system is located in SOS. Especially, land sea level change is critical factor to change flood resilience since it is one of the most substantial disturbance that changes the entire boundary of SOS. In order to have broader perspective of vulnerability and resilience of the coastal region, it is crucial to understand the land sea level dynamics changed with human activities and natural variances.The risk of land sea level change has been researched , but most of these researches have focused on explain cause and effect of land sea level change, paying little attention to its dynamics interacts with human activities. Thus, an objective of this research is to study dynamics of human work, land sea level change and resilience to flood with SOS approach. Especially, we focus on the case in Ganges-Brahmaputra, Bangladesh where has high vulnerability to flood, and is faced with relatively rapid land sea level change problem. To acheive the goal, this study will develop a stylized model by extending the human - flood interaction model combined with relative sea level difference equation. The model describes the dynamics of flood protection system which is changed by SHS and land sea level chage. we will focus on the aggradation and human compaction which are highly chaged by human-flood interactions. Carpenter, S. R., W. A. Brock, C. Folke, E. H. van Nes, and M. Scheffer. 2015. Allowing variance may enlarge the safe operating space for exploited ecosystems. Proceedings of the National Academy of Sciences 112(46):14384-14389.

Research on the properties and interactions of simple atomic and ionic systems

NASA Technical Reports Server (NTRS)

Novick, R.

1972-01-01

Simple ionic systems were studied, such as metastable autoionizing states of the negative He ion, two-photon decay spectrum of metastable He ion, optical excitation with low energy ions, and lifetime measurements of singly ionized Li and metastable He ion. Simple atomic systems were also investigated. Metastable autoionizing atomic energy levels in alkali elements were included, along with lifetime measurements of Cr-53, group 2A isotopes, and alkali metal atoms using level crossing and optical double resonance spectroscopy.

Interactive Web-based Floodplain Simulation System for Realistic Experiments of Flooding and Flood Damage

NASA Astrophysics Data System (ADS)

Demir, I.

2013-12-01

Recent developments in web technologies make it easy to manage and visualize large data sets with general public. Novel visualization techniques and dynamic user interfaces allow users to create realistic environments, and interact with data to gain insight from simulations and environmental observations. The floodplain simulation system is a web-based 3D interactive flood simulation environment to create real world flooding scenarios. The simulation systems provides a visually striking platform with realistic terrain information, and water simulation. Students can create and modify predefined scenarios, control environmental parameters, and evaluate flood mitigation techniques. The web-based simulation system provides an environment to children and adults learn about the flooding, flood damage, and effects of development and human activity in the floodplain. The system provides various scenarios customized to fit the age and education level of the users. This presentation provides an overview of the web-based flood simulation system, and demonstrates the capabilities of the system for various flooding and land use scenarios.

Extraction of CYP chemical interactions from biomedical literature using natural language processing methods.

PubMed

Jiao, Dazhi; Wild, David J

2009-02-01

This paper proposes a system that automatically extracts CYP protein and chemical interactions from journal article abstracts, using natural language processing (NLP) and text mining methods. In our system, we employ a maximum entropy based learning method, using results from syntactic, semantic, and lexical analysis of texts. We first present our system architecture and then discuss the data set for training our machine learning based models and the methods in building components in our system, such as part of speech (POS) tagging, Named Entity Recognition (NER), dependency parsing, and relation extraction. An evaluation of the system is conducted at the end, yielding very promising results: The POS, dependency parsing, and NER components in our system have achieved a very high level of accuracy as measured by precision, ranging from 85.9% to 98.5%, and the precision and the recall of the interaction extraction component are 76.0% and 82.6%, and for the overall system are 68.4% and 72.2%, respectively.

Toward an understanding of immune cell sociology: real-time monitoring of cytokine secretion at the single-cell level.

PubMed

Shirasaki, Yoshitaka; Yamagishi, Mai; Shimura, Nanako; Hijikata, Atsushi; Ohara, Osamu

2013-01-01

The immune system is a very complex and dynamic cellular system, and its intricacies are considered akin to those of human society. Disturbance of homeostasis of the immune system results in various types of diseases; therefore, the homeostatic mechanism of the immune system has long been a subject of great interest in biology, and a lot of information has been accumulated at the cellular and the molecular levels. However, the sociological aspects of the immune system remain too abstract to address because of its high complexity, which mainly originates from a large number and variety of cell-cell interactions. As long-range interactions mediated by cytokines play a key role in the homeostasis of the immune system, cytokine secretion analyses, ranging from analyses of the micro level of individual cells to the macro level of a bulk of cell ensembles, provide us with a solid basis of a sociological viewpoint of the immune system. In this review, as the first step toward a comprehensive understanding of immune cell sociology, cytokine secretion of immune cells is surveyed with a special emphasis on the single-cell level, which has been overlooked but should serve as a basis of immune cell sociology. Now that it has become evident that large cell-to-cell variations in cytokine secretion exist at the single-cell level, we face a tricky yet interesting question: How is homeostasis maintained when the system is composed of intrinsically noisy agents? In this context, we discuss how the heterogeneity of cytokine secretion at the single-cell level affects our view of immune cell sociology. While the apparent inconsistency between homeostasis and cell-to-cell heterogeneity is difficult to address by a conventional reductive approach, comparison and integration of single-cell data with macroscopic data will offer us a new direction for the comprehensive understanding of immune cell sociology. Copyright © 2012 International Union of Biochemistry and Molecular Biology, Inc.

Dynamical stabilization of grazing systems: An interplay among plant-water interaction, overgrazing and a threshold management policy.

PubMed

Costa, Michel Iskin da Silveira; Meza, Magno Enrique Mendoza

2006-12-01

In a plant-herbivore system, a management strategy called threshold policy is proposed to control grazing intensity where the vegetation dynamics is described by a plant-water interaction model. It is shown that this policy can lead the vegetation density to a previously chosen level under an overgrazing regime. This result is obtained despite both the potential occurrence of vegetation collapse due to overgrazing and the possibility of complex dynamics sensitive to vegetation initial densities and parameter uncertainties.

Automation effects in a stereotypical multiloop manual control system. [for aircraft

NASA Technical Reports Server (NTRS)

Hess, R. A.; Mcnally, B. D.

1984-01-01

The increasing reliance of state-of-the art, high performance aircraft on high authority stability and command augmentation systems, in order to obtain satisfactory performance and handling qualities, has made critical the achievement of a better understanding of human capabilities, limitations, and preferences during interactions with complex dynamic systems that involve task allocation between man and machine. An analytical and experimental study has been undertaken to investigate human interaction with a simple, multiloop dynamic system in which human activity was systematically varied by changing the levels of automation. Task definition has led to a control loop structure which parallels that for any multiloop manual control system, and may therefore be considered a stereotype.

An affinity-structure database of helix-turn-helix: DNA complexes with a universal coordinate system.

PubMed

AlQuraishi, Mohammed; Tang, Shengdong; Xia, Xide

2015-11-19

Molecular interactions between proteins and DNA molecules underlie many cellular processes, including transcriptional regulation, chromosome replication, and nucleosome positioning. Computational analyses of protein-DNA interactions rely on experimental data characterizing known protein-DNA interactions structurally and biochemically. While many databases exist that contain either structural or biochemical data, few integrate these two data sources in a unified fashion. Such integration is becoming increasingly critical with the rapid growth of structural and biochemical data, and the emergence of algorithms that rely on the synthesis of multiple data types to derive computational models of molecular interactions. We have developed an integrated affinity-structure database in which the experimental and quantitative DNA binding affinities of helix-turn-helix proteins are mapped onto the crystal structures of the corresponding protein-DNA complexes. This database provides access to: (i) protein-DNA structures, (ii) quantitative summaries of protein-DNA binding affinities using position weight matrices, and (iii) raw experimental data of protein-DNA binding instances. Critically, this database establishes a correspondence between experimental structural data and quantitative binding affinity data at the single basepair level. Furthermore, we present a novel alignment algorithm that structurally aligns the protein-DNA complexes in the database and creates a unified residue-level coordinate system for comparing the physico-chemical environments at the interface between complexes. Using this unified coordinate system, we compute the statistics of atomic interactions at the protein-DNA interface of helix-turn-helix proteins. We provide an interactive website for visualization, querying, and analyzing this database, and a downloadable version to facilitate programmatic analysis. This database will facilitate the analysis of protein-DNA interactions and the development of programmatic computational methods that capitalize on integration of structural and biochemical datasets. The database can be accessed at http://ProteinDNA.hms.harvard.edu.

Coastal wetlands, sea level, and the dimensions of geomorphic resilience

NASA Astrophysics Data System (ADS)

Phillips, Jonathan D.

2018-03-01

Geomorphic system resilience is often perceived as an intrinsic property of system structure and interactions but is also related to idiosyncratic place and history factors. The importance of geographical and historical circumstances makes it difficult to generate categorical statements about geomorphic resilience. However, network-based analyses of system structure can be used to determine the dynamical stability (= resilience) based on generally applicable relationships and to determine scenarios of stability or instability. These provide guidelines for assessing place and history factors to assess resilience. A model of coastal wetlands is analyzed, based on interactions among relative sea level, wetland surface elevation, hydroperiod, vegetation, and sedimentation. The system is generally (but not always) dynamically unstable and non-resilient. Because of gradients of environmental factors and patchy distributions of microtopography and vegetation, a coastal wetland landscape may have extensive local variations in stability/resilience and in the key relationships that trigger instabilities. This is illustrated by a case study where dynamically unstable fragmentation is found in two nearby coastal wetlands in North Carolina's Neuse River estuary-Otter Creek Mouth and Anderson Creek. Neither is keeping pace with relative sea level rise, and both show unstable state transitions within the wetland system; but locally stable relationships exist within the wetland systems.

PHYSICAL EFFECTS OCCURRING DURING GENERATION AND AMPLIFICATION OF LASER RADIATION: Self-induced resonance under conditions of radiative equilibrium of quasienergy states in a three-level system

NASA Astrophysics Data System (ADS)

Sarkisyan, M. A.

1989-02-01

An analysis is made of the interaction of a three-level "cascade" atomic system with a resonant laser field. An investigation is made of the dynamics of the populations of the quasienergy states and of the atomic levels over times greater than the spontaneous transition times. In the steady-state regime the distribution of atoms over various quasienergy states is obtained under two-photon resonance conditions and for the case when all the resonances are strong. It is found that a suitable selection of the interaction parameters can establish an inversion between the quasienergy states and also due to atomic transitions. The total probability of spontaneous scattering is calculated. It is shown that, under two-photon resonance conditions, the scattering intensity increases sharply due to a self-induced resonance.

Evaluation of an Audiovisual-FM System: Investigating the Interaction between Illumination Level and a Talker's Skin Color on Speech-Reading Performance

ERIC Educational Resources Information Center

Gagne, Jean-Pierre; Laplante-Levesque, Ariane; Labelle, Maude; Doucet, Katrine; Potvin, Marie-Christine

2006-01-01

A program designed to evaluate the benefits of an audiovisual-frequency modulated (FM) system led to some questions concerning the effects of illumination level and a talker's skin color on speech-reading performance. To address those issues, the speech of a Caucasian female was videotaped under 2 conditions: a light skin color condition and a…

Trends in Process-related Research on Curriculum and Teaching at Different Problem Levels in Educational Sciences

ERIC Educational Resources Information Center

Dahllof, Urban

1974-01-01

A re-analysis is given of the research about the influences of certain environmental factors on student achievement. The study indicates that educational process data seem to be helpful in building up an explanatory model not only on the macro systems level, but also on the classroom interaction level. (Editor)

Analysis of engagement behavior in children during dyadic interactions using prosodic cues⋆

PubMed Central

Gupta, Rahul; Bone, Daniel; Lee, Sungbok; Narayanan, Shrikanth

2017-01-01

Child engagement is defined as the interaction of a child with his/her environment in a contextually appropriate manner. Engagement behavior in children is linked to socio-emotional and cognitive state assessment with enhanced engagement identified with improved skills. A vast majority of studies however rely solely, and often implicitly, on subjective perceptual measures of engagement. Access to automatic quantification could assist researchers/clinicians to objectively interpret engagement with respect to a target behavior or condition, and furthermore inform mechanisms for improving engagement in various settings. In this paper, we present an engagement prediction system based exclusively on vocal cues observed during structured interaction between a child and a psychologist involving several tasks. Specifically, we derive prosodic cues that capture engagement levels across the various tasks. Our experiments suggest that a child’s engagement is reflected not only in the vocalizations, but also in the speech of the interacting psychologist. Moreover, we show that prosodic cues are informative of the engagement phenomena not only as characterized over the entire task (i.e., global cues), but also in short term patterns (i.e., local cues). We perform a classification experiment assigning the engagement of a child into three discrete levels achieving an unweighted average recall of 55.8% (chance is 33.3%). While the systems using global cues and local level cues are each statistically significant in predicting engagement, we obtain the best results after fusing these two components. We perform further analysis of the cues at local and global levels to achieve insights linking specific prosodic patterns to the engagement phenomenon. We observe that while the performance of our model varies with task setting and interacting psychologist, there exist universal prosodic patterns reflective of engagement. PMID:28713198

Analysis of engagement behavior in children during dyadic interactions using prosodic cues.

PubMed

Gupta, Rahul; Bone, Daniel; Lee, Sungbok; Narayanan, Shrikanth

2016-05-01

Child engagement is defined as the interaction of a child with his/her environment in a contextually appropriate manner. Engagement behavior in children is linked to socio-emotional and cognitive state assessment with enhanced engagement identified with improved skills. A vast majority of studies however rely solely, and often implicitly, on subjective perceptual measures of engagement. Access to automatic quantification could assist researchers/clinicians to objectively interpret engagement with respect to a target behavior or condition, and furthermore inform mechanisms for improving engagement in various settings. In this paper, we present an engagement prediction system based exclusively on vocal cues observed during structured interaction between a child and a psychologist involving several tasks. Specifically, we derive prosodic cues that capture engagement levels across the various tasks. Our experiments suggest that a child's engagement is reflected not only in the vocalizations, but also in the speech of the interacting psychologist. Moreover, we show that prosodic cues are informative of the engagement phenomena not only as characterized over the entire task (i.e., global cues), but also in short term patterns (i.e., local cues). We perform a classification experiment assigning the engagement of a child into three discrete levels achieving an unweighted average recall of 55.8% (chance is 33.3%). While the systems using global cues and local level cues are each statistically significant in predicting engagement, we obtain the best results after fusing these two components. We perform further analysis of the cues at local and global levels to achieve insights linking specific prosodic patterns to the engagement phenomenon. We observe that while the performance of our model varies with task setting and interacting psychologist, there exist universal prosodic patterns reflective of engagement.

Transportable, university-level educational programs in interactive information storage and retrieval systems

NASA Technical Reports Server (NTRS)

Dominick, Wayne D.; Roquemore, Leroy

1984-01-01

Pursuant to the specifications of a research contract entered into in December, 1983 with NASA, the Computer Science Departments of the University of Southwestern Louisiana and Southern University will be working jointly to address a variety of research and educational issues relating to the use, by non-computer professionals, of some of the largest and most sophiticated interactive information storage and retrieval systems available. Over the projected 6 to 8 year life of the project, in addition to NASA/RECON, the following systems will be examined: Lockheed DIALOG, DOE/RECON, DOD/DTIC, EPA/CSIN, and LLNL/TIS.

Development of a Laser Induced Fluorescence (LIF) system on the Plasma Material Interaction System (PLAMIS-II) device

NASA Astrophysics Data System (ADS)

Kang, I. J.; Lee, K. Y.; Lee, K. I.; Choi, Y.-S.; Cho, S. G.; Bae, M. K.; Lee, D.-H.; Hong, S. H.; Lho, T.; Chung, K.-S.

2015-12-01

A laser induced fluorescence (LIF) system has been developed for the plasma material interaction system (PLAMIS-II) device, which is equipped with a unique plasma gun composed of a LaB6 cathode and two anodes with electromagnets to generate a focused dense plasma. PLAMIS-II simulates the interactions of plasma with different materials and is to be used for the test of plasma facing components of fusion devices. The LIF system is composed of a seed laser with Littmann/Metcalf cavity and a master oscillator power amplifier to pump 3d4F7/2 metastable argon ion to 4p4D5/2 level at the wavelength of 668.61 nm, which has the following input parameters: laser power = 20 mW, line width < 100 kHz, and a mode-hop free tuning range > 70 GHz. For in-situ measurement of laser wavelength, the wavelength spectrum of an iodine cell was measured by a photo-transistor during LIF measurement. To measure argon ion temperature (Ti) and drift velocity (vd) in PLAMIS-II, the fluorescence light with the wavelength of 442.72 nm, emitted from 4p4D5/2 level to 4s4P3/2 level and passing through 1 nm band-width filter, was collected by the photomultiplier tube combined with a lock-in amplifier and a chopper with frequency of 3 kHz. Initial data of Ti and vd were analysed in terms of gas flow rate and applied power.

A hierarchy of timescales explains distinct effects of local inhibition of primary visual cortex and frontal eye fields

PubMed Central

Cocchi, Luca; Sale, Martin V; L Gollo, Leonardo; Bell, Peter T; Nguyen, Vinh T; Zalesky, Andrew; Breakspear, Michael; Mattingley, Jason B

2016-01-01

Within the primate visual system, areas at lower levels of the cortical hierarchy process basic visual features, whereas those at higher levels, such as the frontal eye fields (FEF), are thought to modulate sensory processes via feedback connections. Despite these functional exchanges during perception, there is little shared activity between early and late visual regions at rest. How interactions emerge between regions encompassing distinct levels of the visual hierarchy remains unknown. Here we combined neuroimaging, non-invasive cortical stimulation and computational modelling to characterize changes in functional interactions across widespread neural networks before and after local inhibition of primary visual cortex or FEF. We found that stimulation of early visual cortex selectively increased feedforward interactions with FEF and extrastriate visual areas, whereas identical stimulation of the FEF decreased feedback interactions with early visual areas. Computational modelling suggests that these opposing effects reflect a fast-slow timescale hierarchy from sensory to association areas. DOI: http://dx.doi.org/10.7554/eLife.15252.001 PMID:27596931

Transient protein-protein interactions perturb E. coli metabolome and cause gene dosage toxicity

PubMed Central

Bhattacharyya, Sanchari; Bershtein, Shimon; Yan, Jin; Argun, Tijda; Gilson, Amy I; Trauger, Sunia A; Shakhnovich, Eugene I

2016-01-01

Gene dosage toxicity (GDT) is an important factor that determines optimal levels of protein abundances, yet its molecular underpinnings remain unknown. Here, we demonstrate that overexpression of DHFR in E. coli causes a toxic metabolic imbalance triggered by interactions with several functionally related enzymes. Though deleterious in the overexpression regime, surprisingly, these interactions are beneficial at physiological concentrations, implying their functional significance in vivo. Moreover, we found that overexpression of orthologous DHFR proteins had minimal effect on all levels of cellular organization – molecular, systems, and phenotypic, in sharp contrast to E. coli DHFR. Dramatic difference of GDT between ‘E. coli’s self’ and ‘foreign’ proteins suggests the crucial role of evolutionary selection in shaping protein-protein interaction (PPI) networks at the whole proteome level. This study shows how protein overexpression perturbs a dynamic metabolon of weak yet potentially functional PPI, with consequences for the metabolic state of cells and their fitness. DOI: http://dx.doi.org/10.7554/eLife.20309.001 PMID:27938662

A hierarchy of timescales explains distinct effects of local inhibition of primary visual cortex and frontal eye fields.

PubMed

Cocchi, Luca; Sale, Martin V; L Gollo, Leonardo; Bell, Peter T; Nguyen, Vinh T; Zalesky, Andrew; Breakspear, Michael; Mattingley, Jason B

2016-09-06

Within the primate visual system, areas at lower levels of the cortical hierarchy process basic visual features, whereas those at higher levels, such as the frontal eye fields (FEF), are thought to modulate sensory processes via feedback connections. Despite these functional exchanges during perception, there is little shared activity between early and late visual regions at rest. How interactions emerge between regions encompassing distinct levels of the visual hierarchy remains unknown. Here we combined neuroimaging, non-invasive cortical stimulation and computational modelling to characterize changes in functional interactions across widespread neural networks before and after local inhibition of primary visual cortex or FEF. We found that stimulation of early visual cortex selectively increased feedforward interactions with FEF and extrastriate visual areas, whereas identical stimulation of the FEF decreased feedback interactions with early visual areas. Computational modelling suggests that these opposing effects reflect a fast-slow timescale hierarchy from sensory to association areas.

Novel design of interactive multimodal biofeedback system for neurorehabilitation.

PubMed

Huang, He; Chen, Y; Xu, W; Sundaram, H; Olson, L; Ingalls, T; Rikakis, T; He, Jiping

2006-01-01

A previous design of a biofeedback system for Neurorehabilitation in an interactive multimodal environment has demonstrated the potential of engaging stroke patients in task-oriented neuromotor rehabilitation. This report explores the new concept and alternative designs of multimedia based biofeedback systems. In this system, the new interactive multimodal environment was constructed with abstract presentation of movement parameters. Scenery images or pictures and their clarity and orientation are used to reflect the arm movement and relative position to the target instead of the animated arm. The multiple biofeedback parameters were classified into different hierarchical levels w.r.t. importance of each movement parameter to performance. A new quantified measurement for these parameters were developed to assess the patient's performance both real-time and offline. These parameters were represented by combined visual and auditory presentations with various distinct music instruments. Overall, the objective of newly designed system is to explore what information and how to feedback information in interactive virtual environment could enhance the sensorimotor integration that may facilitate the efficient design and application of virtual environment based therapeutic intervention.

Rehabilitation Aids.

ERIC Educational Resources Information Center

National Center on Educational Media and Materials for the Handicapped, Columbus, OH.

Selected from the National Instructional Materials Information System (NIMIS)--a computer based on-line interactive retrieval system on special education materials--the bibliography covers 40 equipment items for rehabilitation and physical therapy programs for all levels of handicapped children. Described are such items as a handygym, a suspension…

Deconstructing Memory in Drosophila

PubMed Central

Margulies, Carla; Tully, Tim; Dubnau, Josh

2011-01-01

Unlike most organ systems, which have evolved to maintain homeostasis, the brain has been selected to sense and adapt to environmental stimuli by constantly altering interactions in a gene network that functions within a larger neural network. This unique feature of the central nervous system provides a remarkable plasticity of behavior, but also makes experimental investigations challenging. Each experimental intervention ramifies through both gene and neural networks, resulting in unpredicted and sometimes confusing phenotypic adaptations. Experimental dissection of mechanisms underlying behavioral plasticity ultimately must accomplish an integration across many levels of biological organization, including genetic pathways acting within individual neurons, neural network interactions which feed back to gene function, and phenotypic observations at the behavioral level. This dissection will be more easily accomplished for model systems such as Drosophila, which, compared with mammals, have relatively simple and manipulable nervous systems and genomes. The evolutionary conservation of behavioral phenotype and the underlying gene function ensures that much of what we learn in such model systems will be relevant to human cognition. In this essay, we have not attempted to review the entire Drosophila memory field. Instead, we have tried to discuss particular findings that provide some level of intellectual synthesis across three levels of biological organization: behavior, neural circuitry and biochemical pathways. We have attempted to use this integrative approach to evaluate distinct mechanistic hypotheses, and to propose critical experiments that will advance this field. PMID:16139203

Multidisciplinary model-based-engineering for laser weapon systems: recent progress

NASA Astrophysics Data System (ADS)

Coy, Steve; Panthaki, Malcolm

2013-09-01

We are working to develop a comprehensive, integrated software framework and toolset to support model-based engineering (MBE) of laser weapons systems. MBE has been identified by the Office of the Director, Defense Science and Engineering as one of four potentially "game-changing" technologies that could bring about revolutionary advances across the entire DoD research and development and procurement cycle. To be effective, however, MBE requires robust underlying modeling and simulation technologies capable of modeling all the pertinent systems, subsystems, components, effects, and interactions at any level of fidelity that may be required in order to support crucial design decisions at any point in the system development lifecycle. Very often the greatest technical challenges are posed by systems involving interactions that cut across two or more distinct scientific or engineering domains; even in cases where there are excellent tools available for modeling each individual domain, generally none of these domain-specific tools can be used to model the cross-domain interactions. In the case of laser weapons systems R&D these tools need to be able to support modeling of systems involving combined interactions among structures, thermal, and optical effects, including both ray optics and wave optics, controls, atmospheric effects, target interaction, computational fluid dynamics, and spatiotemporal interactions between lasing light and the laser gain medium. To address this problem we are working to extend Comet™, to add the addition modeling and simulation capabilities required for this particular application area. In this paper we will describe our progress to date.

Exploring Adaptability through Learning Layers and Learning Loops

ERIC Educational Resources Information Center

Lof, Annette

2010-01-01

Adaptability in social-ecological systems results from individual and collective action, and multi-level interactions. It can be understood in a dual sense as a system's ability to adapt to disturbance and change, and to navigate system transformation. Inherent in this conception, as found in resilience thinking, are the concepts of learning and…

Micro-Macro Compatibility: When Does a Complex Systems Approach Strongly Benefit Science Learning?

ERIC Educational Resources Information Center

Samon, Sigal; Levy, Sharona T.

2017-01-01

The study explores how a complexity approach empowers science learning. A complexity approach represents systems as many interacting entities. The construct of micro-macro compatibility is introduced, the degree of similarity between behaviors at the micro- and macro-levels of the system. Seventh-grade students' learning about gases was studied…

The Clinical Practice Library of Medicine (CPLM): An on-line biomedical computer library. System documentation

NASA Technical Reports Server (NTRS)

Grams, R. R.

1982-01-01

A system designed to access a large range of available medical textbook information in an online interactive fashion is described. A high level query type database manager, INQUIRE, is used. Operating instructions, system flow diagrams, database descriptions, text generation, and error messages are discussed. User information is provided.

“Respect the way I need to communicate with you”: Healthcare experiences of adults on the autism spectrum

PubMed Central

Nicolaidis, Christina; Raymaker, Dora M.; McDonald, Katherine E.; Baggs, W. Amelia E.V.; Dern, Sebastian; Kapp, Steven K.; Weiner, Michael; Boisclair, Cody; Ashkenazy, Elesia

2016-01-01

Our objective was to obtain an in-depth understanding of autistic adults’ experiences with healthcare and their recommendations for improving care. Our academic-community partnership used a community based participatory research (CBPR) approach to conduct semi-structured, open-ended interviews with 39 autistic adults and 16 people who had experience supporting autistic adults in healthcare settings. Participants identified patient-level, autism-related factors that impact healthcare interactions, including verbal communication skills, sensory sensitivities, challenges with body awareness, slow processing speed, atypical non-verbal communication, and challenges with organization. However, the success of healthcare interactions largely depended on the interplay between patient- and provider-level factors, as well as on the larger context in which patients were receiving care. Provider-level factors included providers’ knowledge about autism in adults, incorrect assumptions about individual patients, willingness to allow written communication, use of accessible language, openness to providing other accommodations, and skill in appropriately incorporating supporters. System-level factors included the availability of supporters, complexity of the healthcare system, accessibility of healthcare facilities, and stigma about autism. Further efforts are needed to empower patients, adequately train providers, increase the accessibility of the healthcare system, and decrease discrimination. PMID:25882392

Cross-scale drivers of natural disturbances prone to anthropogenic amplification: Dynamics of biome-wide bark beetle eruptions

Treesearch

Kenneth F. Raffa; Brian H. Aukema; Barbara J. Bentz; Allan L. Carroll; Jeffrey A. Hicke; Monica G. Turner; William H. Romme

2008-01-01

Biome-scale disturbances by eruptive herbivores provide valuable insights into species interactions, ecosystem-function, and impacts of global change. We present a conceptual framework using one system as a model, emphasizing interactions across levels of biological hierarchy and spatiotemporal scales. Bark beetles are major natural disturbance agents in western North...

What Gene-Environment Interactions Can Tell Us about Social Competence in Typical and Atypical Populations

ERIC Educational Resources Information Center

Iarocci, Grace; Yager, Jodi; Elfers, Theo

2007-01-01

Social competence is a complex human behaviour that is likely to involve a system of genes that interacts with a myriad of environmental risk and protective factors. The search for its genetic and environmental origins and influences is equally complex and will require a multidimensional conceptualization and multiple methods and levels of…

User Centered System Design. Part II: Collected Papers from the UCSD HMI Project.

ERIC Educational Resources Information Center

California Univ., San Diego, La Jolla. Inst. for Cognitive Science.

This report is a collection of 11 recent papers by the Human-Machine Interaction Group at the University of California, San Diego. The following papers are included: (1) "Stages and Levels in Human-Machine Interaction," Donald A. Norman; (2) "The Nature of Expertise in UNIX," Stephen W. Draper; (3) "Users in the Real…

A Macroscopic Analogue of the Nuclear Pairing Potential

ERIC Educational Resources Information Center

Dunlap, Richard A.

2013-01-01

A macroscopic system involving permanent magnets is used as an analogue to nucleons in a nucleus to illustrate the significance of the pairing interaction. This illustrates that the view of the total nuclear energy based only on the nucleon occupancy of the energy levels can yield erroneous results and it is only when the pairing interaction is…

CLIMLAB: a Python-based software toolkit for interactive, process-oriented climate modeling

NASA Astrophysics Data System (ADS)

Rose, B. E. J.

2015-12-01

Global climate is a complex emergent property of the rich interactions between simpler components of the climate system. We build scientific understanding of this system by breaking it down into component process models (e.g. radiation, large-scale dynamics, boundary layer turbulence), understanding each components, and putting them back together. Hands-on experience and freedom to tinker with climate models (whether simple or complex) is invaluable for building physical understanding. CLIMLAB is an open-ended software engine for interactive, process-oriented climate modeling. With CLIMLAB you can interactively mix and match model components, or combine simpler process models together into a more comprehensive model. It was created primarily to support classroom activities, using hands-on modeling to teach fundamentals of climate science at both undergraduate and graduate levels. CLIMLAB is written in Python and ties in with the rich ecosystem of open-source scientific Python tools for numerics and graphics. The IPython notebook format provides an elegant medium for distributing interactive example code. I will give an overview of the current capabilities of CLIMLAB, the curriculum we have developed thus far, and plans for the future. Using CLIMLAB requires some basic Python coding skills. We consider this an educational asset, as we are targeting upper-level undergraduates and Python is an increasingly important language in STEM fields. However CLIMLAB is well suited to be deployed as a computational back-end for a graphical gaming environment based on earth-system modeling.

Microscopic theory of longitudinal sound velocity in charge ordered manganites.

PubMed

Rout, G C; Panda, S

2009-10-14

A microscopic theory of longitudinal sound velocity in a manganite system is reported here. The manganite system is described by a model Hamiltonian consisting of charge density wave (CDW) interaction in the e(g) band, an exchange interaction between spins of the itinerant e(g) band electrons and the core t(2g) electrons, and the Heisenberg interaction of the core level spins. The magnetization and the CDW order parameters are considered within mean-field approximations. The phonon Green's function was calculated by Zubarev's technique and hence the longitudinal velocity of sound was finally calculated for the manganite system. The results show that the elastic spring involved in the velocity of sound exhibits strong stiffening in the CDW phase with a decrease in temperature as observed in experiments.

The NRF2-related interactome and regulome contain multifunctional proteins and fine-tuned autoregulatory loops.

PubMed

Papp, Diána; Lenti, Katalin; Módos, Dezső; Fazekas, Dávid; Dúl, Zoltán; Türei, Dénes; Földvári-Nagy, László; Nussinov, Ruth; Csermely, Péter; Korcsmáros, Tamás

2012-06-21

NRF2 is a well-known, master transcription factor (TF) of oxidative and xenobiotic stress responses. Recent studies uncovered an even wider regulatory role of NRF2 influencing carcinogenesis, inflammation and neurodegeneration. Prompted by these advances here we present a systems-level resource for NRF2 interactome and regulome that includes 289 protein-protein, 7469 TF-DNA and 85 miRNA interactions. As systems-level examples of NRF2-related signaling we identified regulatory loops of NRF2 interacting proteins (e.g., JNK1 and CBP) and a fine-tuned regulatory system, where 35 TFs regulated by NRF2 influence 63 miRNAs that down-regulate NRF2. The presented network and the uncovered regulatory loops may facilitate the development of efficient, NRF2-based therapeutic agents. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Full-dimensional quantum mechanics calculations for the spectroscopic characterization of the isomerization transition states of HOCO/DOCO systems.

PubMed

Ma, Dandan; Ren, Haisheng; Ma, Jianyi

2018-02-14

Full-dimensional quantum mechanics calculations were performed to determine the vibrational energy levels of HOCO and DOCO based on an accurate potential energy surface. Almost all of the vibrational energy levels up to 3500 cm -1 from the vibrational ground state were assigned, and the calculated energy levels in this work are well in agreement with the reported results by Bowman. The corresponding full dimensional wavefunctions present some special features. When the energy level approaches the barrier height, the trans-HOCO and cis-HOCO states strongly couple through tunneling interactions, and the tunneling interaction and Fermi resonance were observed in the DOCO system. The energy level patterns of trans-HOCO, cis-HOCO and trans-DOCO provide a reasonable fitted barrier height using the fitting formula of Field et al., however, a discrepancy exists for the cis-DOCO species which is considered as a random event. Our full-dimensional calculations give positive evidence for the accuracy of the spectroscopic characterization model of the isomerization transition state reported by Field et al., which was developed from one-dimensional model systems. Furthermore, the special case of cis-DOCO in this work means that the isotopic substitution can solve the problem of the accidental failure of Field's spectroscopic characterization model.

Generic dynamical features of quenched interacting quantum systems: Survival probability, density imbalance, and out-of-time-ordered correlator

NASA Astrophysics Data System (ADS)

Torres-Herrera, E. J.; García-García, Antonio M.; Santos, Lea F.

2018-02-01

We study numerically and analytically the quench dynamics of isolated many-body quantum systems. Using full random matrices from the Gaussian orthogonal ensemble, we obtain analytical expressions for the evolution of the survival probability, density imbalance, and out-of-time-ordered correlator. They are compared with numerical results for a one-dimensional-disordered model with two-body interactions and shown to bound the decay rate of this realistic system. Power-law decays are seen at intermediate times, and dips below the infinite time averages (correlation holes) occur at long times for all three quantities when the system exhibits level repulsion. The fact that these features are shared by both the random matrix and the realistic disordered model indicates that they are generic to nonintegrable interacting quantum systems out of equilibrium. Assisted by the random matrix analytical results, we propose expressions that describe extremely well the dynamics of the realistic chaotic system at different time scales.

Sensemaking in a Value Based Context for Large Scale Complex Engineered Systems

NASA Astrophysics Data System (ADS)

Sikkandar Basha, Nazareen

The design and the development of Large-Scale Complex Engineered Systems (LSCES) requires the involvement of multiple teams and numerous levels of the organization and interactions with large numbers of people and interdisciplinary departments. Traditionally, requirements-driven Systems Engineering (SE) is used in the design and development of these LSCES. The requirements are used to capture the preferences of the stakeholder for the LSCES. Due to the complexity of the system, multiple levels of interactions are required to elicit the requirements of the system within the organization. Since LSCES involves people and interactions between the teams and interdisciplinary departments, it should be socio-technical in nature. The elicitation of the requirements of most large-scale system projects are subjected to creep in time and cost due to the uncertainty and ambiguity of requirements during the design and development. In an organization structure, the cost and time overrun can occur at any level and iterate back and forth thus increasing the cost and time. To avoid such creep past researches have shown that rigorous approaches such as value based designing can be used to control it. But before the rigorous approaches can be used, the decision maker should have a proper understanding of requirements creep and the state of the system when the creep occurs. Sensemaking is used to understand the state of system when the creep occurs and provide a guidance to decision maker. This research proposes the use of the Cynefin framework, sensemaking framework which can be used in the design and development of LSCES. It can aide in understanding the system and decision making to minimize the value gap due to requirements creep by eliminating ambiguity which occurs during design and development. A sample hierarchical organization is used to demonstrate the state of the system at the occurrence of requirements creep in terms of cost and time using the Cynefin framework. These trials are continued for different requirements and at different sub-system level. The results obtained show that the Cynefin framework can be used to improve the value of the system and can be used for predictive analysis. The decision makers can use these findings and use rigorous approaches and improve the design of Large Scale Complex Engineered Systems.

The self-consistent calculation of pseudo-molecule energy levels, construction of energy level correlation diagrams and an automated computation system for SCF-X(Alpha)-SW calculations

NASA Technical Reports Server (NTRS)

Schlosser, H.

1981-01-01

The self consistent calculation of the electronic energy levels of noble gas pseudomolecules formed when a metal surface is bombarded by noble gas ions is discussed along with the construction of energy level correlation diagrams as a function of interatomic spacing. The self consistent field x alpha scattered wave (SCF-Xalpha-SW) method is utilized. Preliminary results on the Ne-Mg system are given. An interactive x alpha programming system, implemented on the LeRC IBM 370 computer, is described in detail. This automated system makes use of special PROCDEFS (procedure definitions) to minimize the data to be entered manually at a remote terminal. Listings of the special PROCDEFS and of typical input data are given.

[The interactions of functional systems at the homeostatic level in normal children and adolescents and in a radioecologically unfavorable environment].

PubMed

Glazachev, O S; Sudakov, K V

1999-01-01

In the article theoretical and application development of one of postulates of the Anokhin's theory of functional systems--the principle of multiparametric interaction is attempted in study of singularities of intersystem relationships of a number of leading functional homeostatic systems in a developing adolescent's organism living in radioecological unfavorable conditions and during rehabilitational procedures with application of interval dosed normobaric hypoxia. On the basis of a dynamic research of parameters cardiorespiratory and vegetative-humoral homeostasis is established, that the acclimatization of a children's organism to the factors of ecological and social risk in regions under small doses of radionuclides contamination is exhibited in reorganization of multiparametric relations of functional systems: a) increase of "rigidity" of intrasystem links separate cardiovascular effectors, b) of maximum activation sympathetic, pituitary-adrenal and pituitary-thyroid axes of a system stress-response, c) lack of intersystem consolidation of cardiorespiratory functional systems at a level of useful adaptive results. Thus character of interaction of homeostatic functional systems, their stability depend on personal combination of typological singularities in "the integral constitution" of the child-types of a vegetative regulation, somatic constitution, versions of emotional uneasiness. Principally important that it is revealed the capability of a correction in intersystem relations of homeostatic parameters, in particular, with the use of interval normobaric hypoxia of training (IHT). Hypoxic indorsements rendering the influence first of all through an exterior link of a functional system of breathing is carry on to recovery of integration of functional systems defining a homeostasis for children as at a level useful adaptive results. Thus the role initially high neurohumoral activity in achievement of best values cerebral, peripheral blood flow, lung ventilation is reduced, the contribution of separate effectors to security of physical functionality and aerobic capabilities of a children's organism "is equilibrated".

Predicting interactions among fishing, ocean warming, and ocean acidification in a marine system with whole-ecosystem models.

PubMed

Griffith, Gary P; Fulton, Elizabeth A; Gorton, Rebecca; Richardson, Anthony J

2012-12-01

An important challenge for conservation is a quantitative understanding of how multiple human stressors will interact to mitigate or exacerbate global environmental change at a community or ecosystem level. We explored the interaction effects of fishing, ocean warming, and ocean acidification over time on 60 functional groups of species in the southeastern Australian marine ecosystem. We tracked changes in relative biomass within a coupled dynamic whole-ecosystem modeling framework that included the biophysical system, human effects, socioeconomics, and management evaluation. We estimated the individual, additive, and interactive effects on the ecosystem and for five community groups (top predators, fishes, benthic invertebrates, plankton, and primary producers). We calculated the size and direction of interaction effects with an additive null model and interpreted results as synergistic (amplified stress), additive (no additional stress), or antagonistic (reduced stress). Individually, only ocean acidification had a negative effect on total biomass. Fishing and ocean warming and ocean warming with ocean acidification had an additive effect on biomass. Adding fishing to ocean warming and ocean acidification significantly changed the direction and magnitude of the interaction effect to a synergistic response on biomass. The interaction effect depended on the response level examined (ecosystem vs. community). For communities, the size, direction, and type of interaction effect varied depending on the combination of stressors. Top predator and fish biomass had a synergistic response to the interaction of all three stressors, whereas biomass of benthic invertebrates responded antagonistically. With our approach, we were able to identify the regional effects of fishing on the size and direction of the interacting effects of ocean warming and ocean acidification. ©2012 Society for Conservation Biology.

CMP‑N‑acetylneuraminic acid synthetase interacts with fragile X related protein 1.

PubMed

Ma, Yun; Tian, Shuai; Wang, Zongbao; Wang, Changbo; Chen, Xiaowei; Li, Wei; Yang, Yang; He, Shuya

2016-08-01

Fragile X mental retardation protein (FMRP), fragile X related 1 protein (FXR1P) and FXR2P are the members of the FMR protein family. These proteins contain two KH domains and a RGG box, which are characteristic of RNA binding proteins. The absence of FMRP, causes fragile X syndrome (FXS), the leading cause of hereditary mental retardation. FXR1P is expressed throughout the body and important for normal muscle development, and its absence causes cardiac abnormality. To investigate the functions of FXR1P, a screen was performed to identify FXR1P‑interacting proteins and determine the biological effect of the interaction. The current study identified CMP‑N‑acetylneuraminic acid synthetase (CMAS) as an interacting protein using the yeast two‑hybrid system, and the interaction between FXR1P and CMAS was validated in yeast using a β‑galactosidase assay and growth studies with selective media. Furthermore, co‑immunoprecipitation was used to analyze the FXR1P/CMAS association and immunofluorescence microscopy was performed to detect expression and intracellular localization of the proteins. The results of the current study indicated that FXR1P and CMAS interact, and colocalize in the cytoplasm and the nucleus of HEK293T and HeLa cells. Accordingly, a fragile X related 1 (FXR1) gene overexpression vector was constructed to investigate the effect of FXR1 overexpression on the level of monosialotetrahexosylganglioside 1 (GM1). The results of the current study suggested that FXR1P is a tissue‑specific regulator of GM1 levels in SH‑SY5Y cells, but not in HEK293T cells. Taken together, the results initially indicate that FXR1P interacts with CMAS, and that FXR1P may enhance the activation of sialic acid via interaction with CMAS, and increase GM1 levels to affect the development of the nervous system, thus providing evidence for further research into the pathogenesis of FXS.

Lateral Interactions in Monolayer Thick Mercury Films

NASA Astrophysics Data System (ADS)

Kime, Yolanda Jan

An understanding of lateral adatom-adatom interactions is often an important part of understanding electronic structure and adsorption energetics in monolayer thick films. In this dissertation I use angle-resolved photoemission and thermal desorption spectroscopies to explore the relationship between the adatom-adatom interaction and other characteristics of the adlayer, such as electronic structure, defects, or coexistent structural phases in the adlayer. Since Hg binds weakly to many substrates, the lateral interactions are often a major contribution to the dynamics of the overlayer. Hg adlayer systems are thus ideal for probing lateral interactions. The electronic structures of Hg adlayers on Ag(100), Cu(100), and Cu_3Au(100) are studied with angle-resolved ultraviolet photoemission. The Hg atomic 5d_{5/2} electronic band is observed to split into two levels following adsorption onto some surfaces. The energetic splitting of the Hg 5d_{5/2} level is found to be directly correlated to the adlayer homogeneous strain energy. The existence of the split off level also depends on the order or disorder of the Hg adlayer. The energetics of Hg adsorption on Cu(100) are probed using thermal desorption spectroscopy. Two different ordered adlayer structures are observed for Hg adsorption on Cu(100) at 200 K. Under some adsorption conditions and over a range of exposures, the two phases are seen to coexist on the surface prior to the thermal desorption process. A phase transition from the more dense to the less dense phase is observed to occur during the thermal desorption process. Inherent differences in defect densities are responsible for the observed differences between lateral interactions measured previously with equilibrium (atom beam scattering) and as measured by the non-equilibrium (thermal desorption) technique reported here. Theoretical and experimental evidence for an indirect through-metal interaction between adatoms is also discussed. Although through-metal interactions may play a role in some adsorption systems, there is little compelling evidence that this effect is significant in many experimental reports where the through metal bond is invoked.

Modelling of human-machine interaction in equipment design of manufacturing cells

NASA Astrophysics Data System (ADS)

Cochran, David S.; Arinez, Jorge F.; Collins, Micah T.; Bi, Zhuming

2017-08-01

This paper proposes a systematic approach to model human-machine interactions (HMIs) in supervisory control of machining operations; it characterises the coexistence of machines and humans for an enterprise to balance the goals of automation/productivity and flexibility/agility. In the proposed HMI model, an operator is associated with a set of behavioural roles as a supervisor for multiple, semi-automated manufacturing processes. The model is innovative in the sense that (1) it represents an HMI based on its functions for process control but provides the flexibility for ongoing improvements in the execution of manufacturing processes; (2) it provides a computational tool to define functional requirements for an operator in HMIs. The proposed model can be used to design production systems at different levels of an enterprise architecture, particularly at the machine level in a production system where operators interact with semi-automation to accomplish the goal of 'autonomation' - automation that augments the capabilities of human beings.

Integrated information storage and transfer with a coherent magnetic device

PubMed Central

Jia, Ning; Banchi, Leonardo; Bayat, Abolfazl; Dong, Guangjiong; Bose, Sougato

2015-01-01

Quantum systems are inherently dissipation-less, making them excellent candidates even for classical information processing. We propose to use an array of large-spin quantum magnets for realizing a device which has two modes of operation: memory and data-bus. While the weakly interacting low-energy levels are used as memory to store classical information (bits), the high-energy levels strongly interact with neighboring magnets and mediate the spatial movement of information through quantum dynamics. Despite the fact that memory and data-bus require different features, which are usually prerogative of different physical systems – well isolation for the memory cells, and strong interactions for the transmission – our proposal avoids the notorious complexity of hybrid structures. The proposed mechanism can be realized with different setups. We specifically show that molecular magnets, as the most promising technology, can implement hundreds of operations within their coherence time, while adatoms on surfaces probed by a scanning tunneling microscope is a future possibility. PMID:26347152

Accurate prediction of polarised high order electrostatic interactions for hydrogen bonded complexes using the machine learning method kriging.

PubMed

Hughes, Timothy J; Kandathil, Shaun M; Popelier, Paul L A

2015-02-05

As intermolecular interactions such as the hydrogen bond are electrostatic in origin, rigorous treatment of this term within force field methodologies should be mandatory. We present a method able of accurately reproducing such interactions for seven van der Waals complexes. It uses atomic multipole moments up to hexadecupole moment mapped to the positions of the nuclear coordinates by the machine learning method kriging. Models were built at three levels of theory: HF/6-31G(**), B3LYP/aug-cc-pVDZ and M06-2X/aug-cc-pVDZ. The quality of the kriging models was measured by their ability to predict the electrostatic interaction energy between atoms in external test examples for which the true energies are known. At all levels of theory, >90% of test cases for small van der Waals complexes were predicted within 1 kJ mol(-1), decreasing to 60-70% of test cases for larger base pair complexes. Models built on moments obtained at B3LYP and M06-2X level generally outperformed those at HF level. For all systems the individual interactions were predicted with a mean unsigned error of less than 1 kJ mol(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

Neural mirroring and social interaction: Motor system involvement during action observation relates to early peer cooperation.

PubMed

Endedijk, H M; Meyer, M; Bekkering, H; Cillessen, A H N; Hunnius, S

2017-04-01

Whether we hand over objects to someone, play a team sport, or make music together, social interaction often involves interpersonal action coordination, both during instances of cooperation and entrainment. Neural mirroring is thought to play a crucial role in processing other's actions and is therefore considered important for social interaction. Still, to date, it is unknown whether interindividual differences in neural mirroring play a role in interpersonal coordination during different instances of social interaction. A relation between neural mirroring and interpersonal coordination has particularly relevant implications for early childhood, since successful early interaction with peers is predictive of a more favorable social development. We examined the relation between neural mirroring and children's interpersonal coordination during peer interaction using EEG and longitudinal behavioral data. Results showed that 4-year-old children with higher levels of motor system involvement during action observation (as indicated by lower beta-power) were more successful in early peer cooperation. This is the first evidence for a relation between motor system involvement during action observation and interpersonal coordination during other instances of social interaction. The findings suggest that interindividual differences in neural mirroring are related to interpersonal coordination and thus successful social interaction. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Empirical evaluation of neutral interactions in host-parasite networks.

PubMed

Canard, E F; Mouquet, N; Mouillot, D; Stanko, M; Miklisova, D; Gravel, D

2014-04-01

While niche-based processes have been invoked extensively to explain the structure of interaction networks, recent studies propose that neutrality could also be of great importance. Under the neutral hypothesis, network structure would simply emerge from random encounters between individuals and thus would be directly linked to species abundance. We investigated the impact of species abundance distributions on qualitative and quantitative metrics of 113 host-parasite networks. We analyzed the concordance between neutral expectations and empirical observations at interaction, species, and network levels. We found that species abundance accurately predicts network metrics at all levels. Despite host-parasite systems being constrained by physiology and immunology, our results suggest that neutrality could also explain, at least partially, their structure. We hypothesize that trait matching would determine potential interactions between species, while abundance would determine their realization.

Interactive, process-oriented climate modeling with CLIMLAB

NASA Astrophysics Data System (ADS)

Rose, B. E. J.

2016-12-01

Global climate is a complex emergent property of the rich interactions between simpler components of the climate system. We build scientific understanding of this system by breaking it down into component process models (e.g. radiation, large-scale dynamics, boundary layer turbulence), understanding each components, and putting them back together. Hands-on experience and freedom to tinker with climate models (whether simple or complex) is invaluable for building physical understanding. CLIMLAB is an open-ended software engine for interactive, process-oriented climate modeling. With CLIMLAB you can interactively mix and match model components, or combine simpler process models together into a more comprehensive model. It was created primarily to support classroom activities, using hands-on modeling to teach fundamentals of climate science at both undergraduate and graduate levels. CLIMLAB is written in Python and ties in with the rich ecosystem of open-source scientific Python tools for numerics and graphics. The Jupyter Notebook format provides an elegant medium for distributing interactive example code. I will give an overview of the current capabilities of CLIMLAB, the curriculum we have developed thus far, and plans for the future. Using CLIMLAB requires some basic Python coding skills. We consider this an educational asset, as we are targeting upper-level undergraduates and Python is an increasingly important language in STEM fields.

Monitoring protein-protein interactions using split synthetic renilla luciferase protein-fragment-assisted complementation.

PubMed

Paulmurugan, R; Gambhir, S S

2003-04-01

In this study we developed an inducible synthetic renilla luciferase protein-fragment-assisted complementation-based bioluminescence assay to quantitatively measure real time protein-protein interactions in mammalian cells. We identified suitable sites to generate fragments of N and C portions of the protein that yield significant recovered activity through complementation. We validate complementation-based activation of split synthetic renilla luciferase protein driven by the interaction of two strongly interacting proteins, MyoD and Id, in five different cell lines utilizing transient transfection studies. The expression level of the system was also modulated by tumor necrosis factor alpha through NFkappaB-promoter/enhancer elements used to drive expression of the N portion of synthetic renilla luciferase reporter gene. This new system should help in studying protein-protein interactions and when used with other split reporters (e.g., split firefly luciferase) should help to monitor different components of an intracellular network.

Monitoring Protein–Protein Interactions Using Split Synthetic Renilla Luciferase Protein-Fragment-Assisted Complementation

PubMed Central

Paulmurugan, R.; Gambhir, S. S.

2014-01-01

In this study we developed an inducible synthetic renilla luciferase protein-fragment-assisted complementation-based bioluminescence assay to quantitatively measure real time protein–protein interactions in mammalian cells. We identified suitable sites to generate fragments of N and C portions of the protein that yield significant recovered activity through complementation. We validate complementation-based activation of split synthetic renilla luciferase protein driven by the interaction of two strongly interacting proteins, MyoD and Id, in five different cell lines utilizing transient transfection studies. The expression level of the system was also modulated by tumor necrosis factor α through NFκB-promoter/enhancer elements used to drive expression of the N portion of synthetic renilla luciferase reporter gene. This new system should help in studying protein–protein interactions and when used with other split reporters (e.g., split firefly luciferase) should help to monitor different components of an intracellular network. PMID:12705589

Molecular imaging of drug-modulated protein-protein interactions in living subjects.

PubMed

Paulmurugan, Ramasamy; Massoud, Tarik F; Huang, Jing; Gambhir, Sanjiv S

2004-03-15

Networks of protein interactions mediate cellular responses to environmental stimuli and direct the execution of many different cellular functional pathways. Small molecules synthesized within cells or recruited from the external environment mediate many protein interactions. The study of small molecule-mediated interactions of proteins is important to understand abnormal signal transduction pathways in cancer and in drug development and validation. In this study, we used split synthetic renilla luciferase (hRLUC) protein fragment-assisted complementation to evaluate heterodimerization of the human proteins FRB and FKBP12 mediated by the small molecule rapamycin. The concentration of rapamycin required for efficient dimerization and that of its competitive binder ascomycin required for dimerization inhibition were studied in cell lines. The system was dually modulated in cell culture at the transcription level, by controlling nuclear factor kappaB promoter/enhancer elements using tumor necrosis factor alpha, and at the interaction level, by controlling the concentration of the dimerizer rapamycin. The rapamycin-mediated dimerization of FRB and FKBP12 also was studied in living mice by locating, quantifying, and timing the hRLUC complementation-based bioluminescence imaging signal using a cooled charged coupled device camera. This split reporter system can be used to efficiently screen small molecule drugs that modulate protein-protein interactions and also to assess drugs in living animals. Both are essential steps in the preclinical evaluation of candidate pharmaceutical agents targeting protein-protein interactions, including signaling pathways in cancer cells.

Probing the strongly driven spin-boson model in a superconducting quantum circuit.

PubMed

Magazzù, L; Forn-Díaz, P; Belyansky, R; Orgiazzi, J-L; Yurtalan, M A; Otto, M R; Lupascu, A; Wilson, C M; Grifoni, M

2018-04-11

Quantum two-level systems interacting with the surroundings are ubiquitous in nature. The interaction suppresses quantum coherence and forces the system towards a steady state. Such dissipative processes are captured by the paradigmatic spin-boson model, describing a two-state particle, the "spin", interacting with an environment formed by harmonic oscillators. A fundamental question to date is to what extent intense coherent driving impacts a strongly dissipative system. Here we investigate experimentally and theoretically a superconducting qubit strongly coupled to an electromagnetic environment and subjected to a coherent drive. This setup realizes the driven Ohmic spin-boson model. We show that the drive reinforces environmental suppression of quantum coherence, and that a coherent-to-incoherent transition can be achieved by tuning the drive amplitude. An out-of-equilibrium detailed balance relation is demonstrated. These results advance fundamental understanding of open quantum systems and bear potential for the design of entangled light-matter states.

The Anthropocene Generalized: Evolution of Exo-Civilizations and Their Planetary Feedback.

PubMed

Frank, A; Carroll-Nellenback, Jonathan; Alberti, M; Kleidon, A

2018-05-01

We present a framework for studying generic behaviors possible in the interaction between a resource-harvesting technological civilization (an exo-civilization) and the planetary environment in which it evolves. Using methods from dynamical systems theory, we introduce and analyze a suite of simple equations modeling a population which consumes resources for the purpose of running a technological civilization and the feedback those resources drive on the state of the host planet. The feedbacks can drive the planet away from the initial state the civilization originated in and into domains that are detrimental to its sustainability. Our models conceptualize the problem primarily in terms of feedbacks from the resource use onto the coupled planetary systems. In addition, we also model the population growth advantages gained via the harvesting of these resources. We present three models of increasing complexity: (1) Civilization-planetary interaction with a single resource; (2) Civilization-planetary interaction with two resources each of which has a different level of planetary system feedback; (3) Civilization-planetary interaction with two resources and nonlinear planetary feedback (i.e., runaways). All three models show distinct classes of exo-civilization trajectories. We find smooth entries into long-term, "sustainable" steady states. We also find population booms followed by various levels of "die-off." Finally, we also observe rapid "collapse" trajectories for which the population approaches n = 0. Our results are part of a program for developing an "Astrobiology of the Anthropocene" in which questions of sustainability, centered on the coupled Earth-system, can be seen in their proper astronomical/planetary context. We conclude by discussing the implications of our results for both the coupled Earth system and for the consideration of exo-civilizations across cosmic history. Key Words: Anthropocene-Astrobiology-Civilization-Dynamical system theory-Exoplanets-Population dynamics. Astrobiology 18, 503-518.

Ocean acidification alters the response of intertidal snails to a key sea star predator.

PubMed

Jellison, Brittany M; Ninokawa, Aaron T; Hill, Tessa M; Sanford, Eric; Gaylord, Brian

2016-06-29

Organism-level effects of ocean acidification (OA) are well recognized. Less understood are OA's consequences for ecological species interactions. Here, we examine a behaviourally mediated predator-prey interaction within the rocky intertidal zone of the temperate eastern Pacific Ocean, using it as a model system to explore OA's capacity to impair invertebrate anti-predator behaviours more broadly. Our system involves the iconic sea star predator, Pisaster ochraceus, that elicits flee responses in numerous gastropod prey. We examine, in particular, the capacity for OA-associated reductions in pH to alter flight behaviours of the black turban snail, Tegula funebralis, an often-abundant and well-studied grazer in the system. We assess interactions between these species at 16 discrete levels of pH, quantifying the full functional response of Tegula under present and near-future OA conditions. Results demonstrate the disruption of snail anti-predator behaviours at low pH, with decreases in the time individuals spend in refuge locations. We also show that fluctuations in pH, including those typical of rock pools inhabited by snails, do not materially change outcomes, implying little capacity for episodically benign pH conditions to aid behavioural recovery. Together, these findings suggest a strong potential for OA to induce cascading community-level shifts within this long-studied ecosystem. © 2016 The Author(s).

Intelligent microchip networks: an agent-on-chip synthesis framework for the design of smart and robust sensor networks

NASA Astrophysics Data System (ADS)

Bosse, Stefan

2013-05-01

Sensorial materials consisting of high-density, miniaturized, and embedded sensor networks require new robust and reliable data processing and communication approaches. Structural health monitoring is one major field of application for sensorial materials. Each sensor node provides some kind of sensor, electronics, data processing, and communication with a strong focus on microchip-level implementation to meet the goals of miniaturization and low-power energy environments, a prerequisite for autonomous behaviour and operation. Reliability requires robustness of the entire system in the presence of node, link, data processing, and communication failures. Interaction between nodes is required to manage and distribute information. One common interaction model is the mobile agent. An agent approach provides stronger autonomy than a traditional object or remote-procedure-call based approach. Agents can decide for themselves, which actions are performed, and they are capable of flexible behaviour, reacting on the environment and other agents, providing some degree of robustness. Traditionally multi-agent systems are abstract programming models which are implemented in software and executed on program controlled computer architectures. This approach does not well scale to micro-chip level and requires full equipped computers and communication structures, and the hardware architecture does not consider and reflect the requirements for agent processing and interaction. We propose and demonstrate a novel design paradigm for reliable distributed data processing systems and a synthesis methodology and framework for multi-agent systems implementable entirely on microchip-level with resource and power constrained digital logic supporting Agent-On-Chip architectures (AoC). The agent behaviour and mobility is fully integrated on the micro-chip using pipelined communicating processes implemented with finite-state machines and register-transfer logic. The agent behaviour, interaction (communication), and mobility features are modelled and specified on a machine-independent abstract programming level using a state-based agent behaviour language (APL). With this APL a high-level agent compiler is able to synthesize a hardware model (RTL, VHDL), a software model (C, ML), or a simulation model (XML) suitable to simulate a multi-agent system using the SeSAm simulator framework. Agent communication is provided by a simple tuple-space database implemented on node level providing fault tolerant access of global data. A novel synthesis development kit (SynDK) based on a graph-structured database approach is introduced to support the rapid development of compilers and synthesis tools, used for example for the design and implementation of the APL compiler.

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

PubMed

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

2013-06-01

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

Quantum iSWAP gate in optical cavities with a cyclic three-level system

NASA Astrophysics Data System (ADS)

Yan, Guo-an; Qiao, Hao-xue; Lu, Hua

2018-04-01

In this paper we present a scheme to directly implement the iSWAP gate by passing a cyclic three-level system across a two-mode cavity quantum electrodynamics. In the scheme, a three-level Δ -type atom ensemble prepared in its ground state mediates the interaction between the two-cavity modes. For this theoretical model, we also analyze its performance under practical noise, including spontaneous emission and the decay of the cavity modes. It is shown that our scheme may have a high fidelity under the practical noise.

Self-organization processes in field-invasion team sports : implications for leadership.

PubMed

Passos, Pedro; Araújo, Duarte; Davids, Keith

2013-01-01

In nature, the interactions between agents in a complex system (fish schools; colonies of ants) are governed by information that is locally created. Each agent self-organizes (adjusts) its behaviour, not through a central command centre, but based on variables that emerge from the interactions with other system agents in the neighbourhood. Self-organization has been proposed as a mechanism to explain the tendencies for individual performers to interact with each other in field-invasion sports teams, displaying functional co-adaptive behaviours, without the need for central control. The relevance of self-organization as a mechanism that explains pattern-forming dynamics within attacker-defender interactions in field-invasion sports has been sustained in the literature. Nonetheless, other levels of interpersonal coordination, such as intra-team interactions, still raise important questions, particularly with reference to the role of leadership or match strategies that have been prescribed in advance by a coach. The existence of key properties of complex systems, such as system degeneracy, nonlinearity or contextual dependency, suggests that self-organization is a functional mechanism to explain the emergence of interpersonal coordination tendencies within intra-team interactions. In this opinion article we propose how leadership may act as a key constraint on the emergent, self-organizational tendencies of performers in field-invasion sports.

Determining robot actions for tasks requiring sensor interaction

NASA Technical Reports Server (NTRS)

Budenske, John; Gini, Maria

1989-01-01

The performance of non-trivial tasks by a mobile robot has been a long term objective of robotic research. One of the major stumbling blocks to this goal is the conversion of the high-level planning goals and commands into the actuator and sensor processing controls. In order for a mobile robot to accomplish a non-trivial task, the task must be described in terms of primitive actions of the robot's actuators. Most non-trivial tasks require the robot to interact with its environment; thus necessitating coordination of sensor processing and actuator control to accomplish the task. The main contention is that the transformation from the high level description of the task to the primitive actions should be performed primarily at execution time, when knowledge about the environment can be obtained through sensors. It is proposed to produce the detailed plan of primitive actions by using a collection of low-level planning components that contain domain specific knowledge and knowledge about the available sensors, actuators, and sensor/actuator processing. This collection will perform signal and control processing as well as serve as a control interface between an actual mobile robot and a high-level planning system. Previous research has shown the usefulness of high-level planning systems to plan the coordination of activities such to achieve a goal, but none have been fully applied to actual mobile robots due to the complexity of interacting with sensors and actuators. This control interface is currently being implemented on a LABMATE mobile robot connected to a SUN workstation and will be developed such to enable the LABMATE to perform non-trivial, sensor-intensive tasks as specified by a planning system.

Observing real-time social interaction via telecommunication methods in budgerigars (Melopsittacus undulatus).

PubMed

Ikkatai, Yuko; Okanoya, Kazuo; Seki, Yoshimasa

2016-07-01

Humans communicate with one another not only face-to-face but also via modern telecommunication methods such as television and video conferencing. We readily detect the difference between people actively communicating with us and people merely acting via a broadcasting system. We developed an animal model of this novel communication method seen in humans to determine whether animals also make this distinction. We built a system for two animals to interact via audio-visual equipment in real-time, to compare behavioral differences between two conditions, an "interactive two-way condition" and a "non-interactive (one-way) condition." We measured birds' responses to stimuli which appeared in these two conditions. We used budgerigars, which are small, gregarious birds, and found that the frequency of vocal interaction with other individuals did not differ between the two conditions. However, body synchrony between the two birds was observed more often in the interactive condition, suggesting budgerigars recognized the difference between these interactive and non-interactive conditions on some level. Copyright © 2016 Elsevier B.V. All rights reserved.

Device Access Abstractions for Resilient Information Architecture Platform for Smart Grid

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

Dubey, Abhishek; Karsai, Gabor; Volgyesi, Peter

An open application platform distributes the intelligence and control capability to local endpoints (or nodes) reducing total network traffic, improving speed of local actions by avoiding latency, and improving reliability by reducing dependencies on numerous devices and communication interfaces. The platform must be multi-tasking and able to host multiple applications running simultaneously. Given such a system, the core functions of power grid control systems include grid state determination, low level control, fault intelligence and reconfiguration, outage intelligence, power quality measurement, remote asset monitoring, configuration management, power and energy management (including local distributed energy resources, such as wind, solar and energymore » storage) can be eventually distributed. However, making this move requires extensive regression testing of systems to prove out new technologies, such as phasor measurement units (PMU). Additionally, as the complexity of the systems increase with the inclusion of new functionality (especially at the distribution and consumer levels), hidden coupling issues becomes a challenge with possible N-way interactions known and not known by device and application developers. Therefore, it is very important to provide core abstractions that ensure uniform operational semantics across such interactions. Here in this paper, we describe the pattern for abstracting device interactions we have developed for the RIAPS platform in the context of a microgrid control application we have developed.« less

Device Access Abstractions for Resilient Information Architecture Platform for Smart Grid

DOE PAGES

Dubey, Abhishek; Karsai, Gabor; Volgyesi, Peter; ...

2018-06-12

An open application platform distributes the intelligence and control capability to local endpoints (or nodes) reducing total network traffic, improving speed of local actions by avoiding latency, and improving reliability by reducing dependencies on numerous devices and communication interfaces. The platform must be multi-tasking and able to host multiple applications running simultaneously. Given such a system, the core functions of power grid control systems include grid state determination, low level control, fault intelligence and reconfiguration, outage intelligence, power quality measurement, remote asset monitoring, configuration management, power and energy management (including local distributed energy resources, such as wind, solar and energymore » storage) can be eventually distributed. However, making this move requires extensive regression testing of systems to prove out new technologies, such as phasor measurement units (PMU). Additionally, as the complexity of the systems increase with the inclusion of new functionality (especially at the distribution and consumer levels), hidden coupling issues becomes a challenge with possible N-way interactions known and not known by device and application developers. Therefore, it is very important to provide core abstractions that ensure uniform operational semantics across such interactions. Here in this paper, we describe the pattern for abstracting device interactions we have developed for the RIAPS platform in the context of a microgrid control application we have developed.« less

Groundwater levels for selected wells in Upper Kittitas County, Washington

USGS Publications Warehouse

Fasser, E.T.; Julich, R.J.

2011-01-01

Groundwater levels for selected wells in Upper Kittitas County, Washington, are presented on an interactive, web-based map to document the spatial distribution of groundwater levels in the study area measured during spring 2011. Groundwater-level data and well information were collected by the U.S. Geological Survey using standard techniques and are stored in the U.S. Geological Survey National Water Information System, Groundwater Site-Inventory database.

A System Biology Perspective on Environment-Host-Microbe Interactions.

PubMed

Chen, Lianmin; Garmaeva, Sanzhima; Zherankova, Alexandra; Fu, Jingyuan; Wijmenga, Cisca

2018-04-16

A vast, complex and dynamic consortium of microorganisms known as the gut microbiome colonizes the human gut. Over the past few decades we have developed an increased awareness of its important role in human health. In this review we discuss the role of the gut microbiome in complex diseases and the possible causal scenarios behind its interactions with the host genome and environmental factors. We then propose a new analysis framework that combines a systems biology approach, cross-kingdom integration of multiple levels of omics data, and innovative in vitro models to yield an integrated picture of human host-microbe interactions. This new framework will lay the foundation for the development of the next phase in personalized medicine.

Optimal Correlations in Many-Body Quantum Systems

NASA Astrophysics Data System (ADS)

Amico, L.; Rossini, D.; Hamma, A.; Korepin, V. E.

2012-06-01

Information and correlations in a quantum system are closely related through the process of measurement. We explore such relation in a many-body quantum setting, effectively bridging between quantum metrology and condensed matter physics. To this aim we adopt the information-theory view of correlations and study the amount of correlations after certain classes of positive-operator-valued measurements are locally performed. As many-body systems, we consider a one-dimensional array of interacting two-level systems (a spin chain) at zero temperature, where quantum effects are most pronounced. We demonstrate how the optimal strategy to extract the correlations depends on the quantum phase through a subtle interplay between local interactions and coherence.

On the control of spin-boson systems

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

Boscain, Ugo, E-mail: ugo.boscain@polytechnique.edu; Mason, Paolo, E-mail: Paolo.Mason@l2s.centralesupelec.fr; Panati, Gianluca, E-mail: panati@mat.uniroma1.it

2015-09-15

In this paper, we study the so-called spin-boson system, namely, a two-level system in interaction with a distinguished mode of a quantized bosonic field. We give a brief description of the controlled Rabi and Jaynes–Cummings models and we discuss their appearance in the mathematics and physics literature. We then study the controllability of the Rabi model when the control is an external field acting on the bosonic part. Applying geometric control techniques to the Galerkin approximation and using perturbation theory to guarantee non-resonance of the spectrum of the drift operator, we prove approximate controllability of the system, for almost everymore » value of the interaction parameter.« less

The neurobiology of climate change

NASA Astrophysics Data System (ADS)

O'Donnell, Sean

2018-02-01

Directional climate change (global warming) is causing rapid alterations in animals' environments. Because the nervous system is at the forefront of animals' interactions with the environment, the neurobiological implications of climate change are central to understanding how individuals, and ultimately populations, will respond to global warming. Evidence is accumulating for individual level, mechanistic effects of climate change on nervous system development and performance. Climate change can also alter sensory stimuli, changing the effectiveness of sensory and cognitive systems for achieving biological fitness. At the population level, natural selection forces stemming from directional climate change may drive rapid evolutionary change in nervous system structure and function.

The neurobiology of climate change.

PubMed

O'Donnell, Sean

2018-01-06

Directional climate change (global warming) is causing rapid alterations in animals' environments. Because the nervous system is at the forefront of animals' interactions with the environment, the neurobiological implications of climate change are central to understanding how individuals, and ultimately populations, will respond to global warming. Evidence is accumulating for individual level, mechanistic effects of climate change on nervous system development and performance. Climate change can also alter sensory stimuli, changing the effectiveness of sensory and cognitive systems for achieving biological fitness. At the population level, natural selection forces stemming from directional climate change may drive rapid evolutionary change in nervous system structure and function.

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

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

Modeling Complex Cross-Systems Software Interfaces Using SysML

NASA Technical Reports Server (NTRS)

Mandutianu, Sanda; Morillo, Ron; Simpson, Kim; Liepack, Otfrid; Bonanne, Kevin

2013-01-01

The complex flight and ground systems for NASA human space exploration are designed, built, operated and managed as separate programs and projects. However, each system relies on one or more of the other systems in order to accomplish specific mission objectives, creating a complex, tightly coupled architecture. Thus, there is a fundamental need to understand how each system interacts with the other. To determine if a model-based system engineering approach could be utilized to assist with understanding the complex system interactions, the NASA Engineering and Safety Center (NESC) sponsored a task to develop an approach for performing cross-system behavior modeling. This paper presents the results of applying Model Based Systems Engineering (MBSE) principles using the System Modeling Language (SysML) to define cross-system behaviors and how they map to crosssystem software interfaces documented in system-level Interface Control Documents (ICDs).

A Pipeline for Constructing a Catalog of Multi-method Models of Interacting Galaxies

NASA Astrophysics Data System (ADS)

Holincheck, Anthony

Galaxies represent a fundamental unit of matter for describing the large-scale structure of the universe. One of the major processes affecting the formation and evolution of galaxies are mutual interactions. These interactions can including gravitational tidal distortion, mass transfer, and even mergers. In any hierarchical model, mergers are the key mechanism in galaxy formation and evolution. Computer simulations of interacting galaxies have evolved in the last four decades from simple restricted three-body algorithms to full n-body gravity models. These codes often included sophisticated physical mechanisms such as gas dynamics, supernova feedback, and central blackholes. As the level of complexity, and perhaps realism, increases so does the amount of computational resources needed. These advanced simulations are often used in parameter studies of interactions. They are usually only employed in an ad hoc fashion to recreate the dynamical history of specific sets of interacting galaxies. These specific models are often created with only a few dozen or at most few hundred sets of simulation parameters being attempted. This dissertation presents a prototype pipeline for modeling specific pairs of interacting galaxies in bulk. The process begins with a simple image of the current disturbed morphology and an estimate of distance to the system and mass of the galaxies. With the use of an updated restricted three-body simulation code and the help of Citizen Scientists, the pipeline is able to sample hundreds of thousands of points in parameter space for each system. Through the use of a convenient interface and innovative scoring algorithm, the pipeline aids researchers in identifying the best set of simulation parameters. This dissertation demonstrates a successful recreation of the disturbed morphologies of 62 pairs of interacting galaxies. The pipeline also provides for examining the level of convergence and uniqueness of the dynamical properties of each system. By creating a population of models for actual systems, the current research is able to compare simulation-based and observational values on a larger scale than previous efforts. Several potential relationships between star formation rate and dynamical time since closest approach are presented.

Robots with a sense of touch

NASA Astrophysics Data System (ADS)

Bartolozzi, Chiara; Natale, Lorenzo; Nori, Francesco; Metta, Giorgio

2016-09-01

Tactile sensors provide robots with the ability to interact with humans and the environment with great accuracy, yet technical challenges remain for electronic-skin systems to reach human-level performance.

Time-dependent interaction between a two-level atom and a su(1,1) Lie algebra quantum system

NASA Astrophysics Data System (ADS)

Abdalla, M. Sebaweh; Khalil, E. M.; Obada, A.-S. F.

2017-06-01

The problem of the interaction between a two-level atom and a two-mode field in the parametric amplifier-type is considered. A similar problem appears in an ion trapped in a two-dimensional trap. The problem is transformed into an interaction governed by su(1,1) Lie algebraic operators with phase and coupling parameter depending on time. Under an integrability condition, that relates phase and coupling, a solution to the wavefunction is obtained using the Schrödinger equation. The effects of the functional dependence of the coupling and the initial state of the two-level atom on atomic inversion, the degree of entanglement, the fidelity and the Glauber second-order correlation function are investigated. It is shown that the acceleration term plays an important role in controlling the function behavior of the considered quantities.

A multilevel control system for the large space telescope. [numerical analysis/optimal control

NASA Technical Reports Server (NTRS)

Siljak, D. D.; Sundareshan, S. K.; Vukcevic, M. B.

1975-01-01

A multilevel scheme was proposed for control of Large Space Telescope (LST) modeled by a three-axis-six-order nonlinear equation. Local controllers were used on the subsystem level to stabilize motions corresponding to the three axes. Global controllers were applied to reduce (and sometimes nullify) the interactions among the subsystems. A multilevel optimization method was developed whereby local quadratic optimizations were performed on the subsystem level, and global control was again used to reduce (nullify) the effect of interactions. The multilevel stabilization and optimization methods are presented as general tools for design and then used in the design of the LST Control System. The methods are entirely computerized, so that they can accommodate higher order LST models with both conceptual and numerical advantages over standard straightforward design techniques.

Commercial Motion Sensor Based Low-Cost and Convenient Interactive Treadmill.

PubMed

Kim, Jonghyun; Gravunder, Andrew; Park, Hyung-Soon

2015-09-17

Interactive treadmills were developed to improve the simulation of overground walking when compared to conventional treadmills. However, currently available interactive treadmills are expensive and inconvenient, which limits their use. We propose a low-cost and convenient version of the interactive treadmill that does not require expensive equipment and a complicated setup. As a substitute for high-cost sensors, such as motion capture systems, a low-cost motion sensor was used to recognize the subject's intention for speed changing. Moreover, the sensor enables the subject to make a convenient and safe stop using gesture recognition. For further cost reduction, the novel interactive treadmill was based on an inexpensive treadmill platform and a novel high-level speed control scheme was applied to maximize performance for simulating overground walking. Pilot tests with ten healthy subjects were conducted and results demonstrated that the proposed treadmill achieves similar performance to a typical, costly, interactive treadmill that contains a motion capture system and an instrumented treadmill, while providing a convenient and safe method for stopping.

Fish Swim, Rocks Sit, and Lungs Breathe: Expert-Novice Understanding of Complex Systems

ERIC Educational Resources Information Center

Hmelo-Silver, Cindy E.; Marathe, Surabhi; Liu, Lei

2007-01-01

Understanding complex systems is fundamental to understanding science. The complexity of such systems makes them very difficult to understand because they are composed of multiple interrelated levels that interact in dynamic ways. The goal of this study was to understand how experts and novices differed in their understanding of two complex…

Guidelines for the Development and Implementation of a Logistic Resource Annex to the Five Year Defense Program. Volume 2. A Logistic Resource Annex for the Navy DNFYP

DTIC Science & Technology

1978-10-01

Force , Navy and Marine Corps. Coverage is less comprehensive on the Army because of work on this topic by the General Research Corporation. Volume I...presents recommendations on an OSD-level LRA data system. Volumes II, III, and IV cQver the Navy, Air Force , and Marine Corps respectively. Each of these...Resource Model/ Force Level Analysis Interactive Language System NAVAIR Naval Air Systems Command NAVCOMPT Navy Comptroller NAVFAC Naval Facilities

RNA-Binding Proteins in Trichomonas vaginalis: Atypical Multifunctional Proteins.

PubMed

Figueroa-Angulo, Elisa E; Calla-Choque, Jaeson S; Mancilla-Olea, Maria Inocente; Arroyo, Rossana

2015-11-26

Iron homeostasis is highly regulated in vertebrates through a regulatory system mediated by RNA-protein interactions between the iron regulatory proteins (IRPs) that interact with an iron responsive element (IRE) located in certain mRNAs, dubbed the IRE-IRP regulatory system. Trichomonas vaginalis, the causal agent of trichomoniasis, presents high iron dependency to regulate its growth, metabolism, and virulence properties. Although T. vaginalis lacks IRPs or proteins with aconitase activity, possesses gene expression mechanisms of iron regulation at the transcriptional and posttranscriptional levels. However, only one gene with iron regulation at the transcriptional level has been described. Recently, our research group described an iron posttranscriptional regulatory mechanism in the T. vaginalis tvcp4 and tvcp12 cysteine proteinase mRNAs. The tvcp4 and tvcp12 mRNAs have a stem-loop structure in the 5'-coding region or in the 3'-UTR, respectively that interacts with T. vaginalis multifunctional proteins HSP70, α-Actinin, and Actin under iron starvation condition, causing translation inhibition or mRNA stabilization similar to the previously characterized IRE-IRP system in eukaryotes. Herein, we summarize recent progress and shed some light on atypical RNA-binding proteins that may participate in the iron posttranscriptional regulation in T. vaginalis.

Many-body localization in a long range XXZ model with random-field

NASA Astrophysics Data System (ADS)

Li, Bo

2016-12-01

Many-body localization (MBL) in a long range interaction XXZ model with random field are investigated. Using the exact diagonal method, the MBL phase diagram with different tuning parameters and interaction range is obtained. It is found that the phase diagram of finite size results supplies strong evidence to confirm that the threshold interaction exponent α = 2. The tuning parameter Δ can efficiently change the MBL edge in high energy density stats, thus the system can be controlled to transfer from thermal phase to MBL phase by changing Δ. The energy level statistics data are consistent with result of the MBL phase diagram. However energy level statistics data cannot detect the thermal phase correctly in extreme long range case.

Forward rotor vortex effects on counter rotating propeller noise

NASA Technical Reports Server (NTRS)

Laur, Michele; Squires, Becky; Nagel, Robert T.

1992-01-01

Three configurations of a model counter rotating propeller manipulate the blade tip flow by: placing the CRP at angle of attack, installing shrouds, and turning the upstream blades to provide forward sweep. Flow visualization and flow measurements with thermal anemometry show no evidence of a tip vortex; however, a leading edge vortex was detected on aft swept blades. The modifications served to alter the strength and/or path of the leading edge vortex. The vortical flow is eliminated by forward sweep on the upstream propeller blades. Far field acoustic data from each test indicate only small influences on the level and directivity of the BPFs. The interaction tone at the sum of the two BPF's was significantly altered in a consistent manner. As the vortex system varied, the interaction tone was affected: far field noise levels in the forward quandrant increased and the characteristic noise minimum near the plane of rotation became less pronounced and in some cases were eliminated. If the forward propeller leading edge vortex system does not impact the rear propeller in the standard manner, a net increase in the primary interaction tone occurs for the model tested. If the leading edge vortex is removed, the interaction tone increases.

Communications and tracking expert systems study

NASA Technical Reports Server (NTRS)

Leibfried, T. F.; Feagin, Terry; Overland, David

1987-01-01

The original objectives of the study consisted of five broad areas of investigation: criteria and issues for explanation of communication and tracking system anomaly detection, isolation, and recovery; data storage simplification issues for fault detection expert systems; data selection procedures for decision tree pruning and optimization to enhance the abstraction of pertinent information for clear explanation; criteria for establishing levels of explanation suited to needs; and analysis of expert system interaction and modularization. Progress was made in all areas, but to a lesser extent in the criteria for establishing levels of explanation suited to needs. Among the types of expert systems studied were those related to anomaly or fault detection, isolation, and recovery.

The effect of solvent polarity on the accumulation of leachables from pharmaceutical product containers.

PubMed

Jenke, Dennis; Odufu, Alex; Poss, Mitchell

2006-02-01

Material/water equilibrium interaction constants (E(b)) were determined for 12 organic model solutes and a plastic material used in pharmaceutical product containers (non-PVC polyolefin). An excellent correlation was obtained between the measured interaction constants and the organic solute's octanol/water partition coefficient. The effect of solvent polarity on E(b) was assessed by examining the interaction between the plastic and selected model solutes in binary ethanol/water mixtures. In general, logE(b) could be linearily related to the polarity of the ethanol/water mixture. This information, coupled with the interaction model, was used to estimate the levels to which container leachables could accumulate in contacted solutions. Such estimates were made for six known leachables of the polyolefin material and compared to the leachable's measured accumulation levels in binary ethanol/water systems. In general, the accumulation level of the leachables increased with increasing solution polarity. For most of the leachables, the measured accumulation level was less than the calculated levels, suggesting that equilibrium was not achieved in the leaching portion of this study. This lack of equilibrium is attributable to the layered structure of the material studied, as such layering retards the migration of the leachables that are derived from the material's non-solution contact layers.

Design Of An Intelligent Robotic System Organizer Via Expert System Tecniques

NASA Astrophysics Data System (ADS)

Yuan, Peter H.; Valavanis, Kimon P.

1989-02-01

Intelligent Robotic Systems are a special type of Intelligent Machines. When modeled based on Vle theory of Intelligent Controls, they are composed of three interactive levels, namely: organization, coordination, and execution, ordered according, to the ,Principle of Increasing, Intelligence with Decreasing Precl.sion. Expert System techniques, are used to design an Intelligent Robotic System Organizer with a dynamic Knowledge Base and an interactive Inference Engine. Task plans are formulated using, either or both of a Probabilistic Approach and Forward Chapling Methodology, depending on pertinent information associated with a spec;fic requested job. The Intelligent Robotic System, Organizer is implemented and tested on a prototype system operating in an uncertain environment. An evaluation of-the performance, of the prototype system is conducted based upon the probability of generating a successful task sequence versus the number of trials taken by the organizer.

Evolutionary games combining two or three pair coordinations on a square lattice

NASA Astrophysics Data System (ADS)

Király, Balázs; Szabó, György

2017-10-01

We study multiagent logit-rule-driven evolutionary games on a square lattice whose pair interactions are composed of a maximal number of nonoverlapping elementary coordination games describing Ising-type interactions between just two of the available strategies. Using Monte Carlo simulations we investigate the macroscopic noise-level-dependent behavior of the two- and three-pair games and the critical properties of the continuous phase transtitions these systems exhibit. The four-strategy game is shown to be equivalent to a system that consists of two independent and identical Ising models.

Evolutionary games combining two or three pair coordinations on a square lattice.

PubMed

Király, Balázs; Szabó, György

2017-10-01

We study multiagent logit-rule-driven evolutionary games on a square lattice whose pair interactions are composed of a maximal number of nonoverlapping elementary coordination games describing Ising-type interactions between just two of the available strategies. Using Monte Carlo simulations we investigate the macroscopic noise-level-dependent behavior of the two- and three-pair games and the critical properties of the continuous phase transtitions these systems exhibit. The four-strategy game is shown to be equivalent to a system that consists of two independent and identical Ising models.

Correlation effects in superconducting quantum dot systems

NASA Astrophysics Data System (ADS)

Pokorný, Vladislav; Žonda, Martin

2018-05-01

We study the effect of electron correlations on a system consisting of a single-level quantum dot with local Coulomb interaction attached to two superconducting leads. We use the single-impurity Anderson model with BCS superconducting baths to study the interplay between the proximity induced electron pairing and the local Coulomb interaction. We show how to solve the model using the continuous-time hybridization-expansion quantum Monte Carlo method. The results obtained for experimentally relevant parameters are compared with results of self-consistent second order perturbation theory as well as with the numerical renormalization group method.

IVTS-CEV (Interactive Video Tape System-Combat Engineer Vehicle) Gunnery Trainer.

DTIC Science & Technology

1981-07-01

video game technology developed for and marketed in consumer video games. The IVTS/CEV is a conceptual/breadboard-level classroom interactive training system designed to train Combat Engineer Vehicle (CEV) gunners in target acquisition and engagement with the main gun. The concept demonstration consists of two units: a gunner station and a display module. The gunner station has optics and gun controls replicating those of the CEV gunner station. The display module contains a standard large-screen color video monitor and a video tape player. The gunner’s sight

Structural interaction with transportation and handling systems

NASA Technical Reports Server (NTRS)

1973-01-01

Problems involved in the handling and transportation of finished space vehicles from the factory to the launch site are presented, in addition to recommendations for properly accounting for in space vehicle structural design, adverse interactions during transportation. Emphasis is given to the protection of vehicle structures against those environments and loads encountered during transportation (including temporary storage) which would exceed the levels that the vehicle can safely withstand. Current practices for verifying vehicle safety are appraised, and some of the capabilities and limitations of transportation and handling systems are summarized.

Machine-related backgrounds in the SiD detector at ILC

NASA Astrophysics Data System (ADS)

Denisov, D. S.; Mokhov, N. V.; Striganov, S. I.; Kostin, M. A.; Tropin, I. S.

2006-12-01

With a multi-stage collimation system and magnetic iron spoilers in the tunnel, the background particle fluxes on the ILC detector can be substantially reduced. At the same time, beam-halo interactions with collimators and protective masks in the beam delivery system create fluxes of muons and other secondary particles which can still exceed the tolerable levels for some of the ILC sub-detectors. Results of modeling of such backgrounds in comparison to those from the e+e- interactions are presented in this paper for the SiD detector.

A database system to support image algorithm evaluation

NASA Technical Reports Server (NTRS)

Lien, Y. E.

1977-01-01

The design is given of an interactive image database system IMDB, which allows the user to create, retrieve, store, display, and manipulate images through the facility of a high-level, interactive image query (IQ) language. The query language IQ permits the user to define false color functions, pixel value transformations, overlay functions, zoom functions, and windows. The user manipulates the images through generic functions. The user can direct images to display devices for visual and qualitative analysis. Image histograms and pixel value distributions can also be computed to obtain a quantitative analysis of images.

Automated synthesis and composition of taskblocks for control of manufacturing systems.

PubMed

Holloway, L E; Guan, X; Sundaravadivelu, R; Ashley, J R

2000-01-01

Automated control synthesis methods for discrete-event systems promise to reduce the time required to develop, debug, and modify control software. Such methods must be able to translate high-level control goals into detailed sequences of actuation and sensing signals. In this paper, we present such a technique. It relies on analysis of a system model, defined as a set of interacting components, each represented as a form of condition system Petri net. Control logic modules, called taskblocks, are synthesized from these individual models. These then interact hierarchically and sequentially to drive the system through specified control goals. The resulting controller is automatically converted to executable control code. The paper concludes with a discussion of a set of software tools developed to demonstrate the techniques on a small manufacturing system.

Structural Bioinformatics of the Interactome

PubMed Central

Petrey, Donald; Honig, Barry

2014-01-01

The last decade has seen a dramatic expansion in the number and range of techniques available to obtain genome-wide information, and to analyze this information so as to infer both the function of individual molecules and how they interact to modulate the behavior of biological systems. Here we review these techniques, focusing on the construction of physical protein-protein interaction networks, and highlighting approaches that incorporate protein structure which is becoming an increasingly important component of systems-level computational techniques. We also discuss how network analyses are being applied to enhance the basic understanding of biological systems and their disregulation, and how they are being applied in drug development. PMID:24895853

First principles molecular dynamics of metal/water interfaces under bias potential

NASA Astrophysics Data System (ADS)

Pedroza, Luana; Brandimarte, Pedro; Rocha, Alexandre; Fernandez-Serra, Marivi

2014-03-01

Understanding the interaction of the water-metal system at an atomic level is extremely important in electrocatalysts for fuel cells, photocatalysis among other systems. The question of the interface energetics involves a detailed study of the nature of the interactions between water-water and water-substrate. A first principles description of all components of the system is the most appropriate methodology in order to advance understanding of electrochemically processes. In this work we describe, using first principles molecular dynamics simulations, the dynamics of a combined surface(Au and Pd)/water system both in the presence and absence of an external bias potential applied to the electrodes, as one would come across in electrochemistry. This is accomplished using a combination of density functional theory (DFT) and non-equilibrium Green's functions methods (NEGF), thus accounting for the fact that one is dealing with an out-of-equilibrium open system, with and without van der Waals interactions. DOE Early Career Award No. DE-SC0003871.

Social-ecological outcomes in recreational fisheries: The interaction of lakeshore development and stocking

USGS Publications Warehouse

Ziegler, Jacob P.; Golebie, Elizabeth J.; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

2017-01-01

Many ecosystems continue to experience rapid transformations due to processes like land use change and resource extraction. A systems approach to maintaining natural resources focuses on how interactions and feedbacks among components of complex social‐ecological systems generate social and ecological outcomes. In recreational fisheries, residential shoreline development and fish stocking are two widespread human behaviors that influence fisheries, yet emergent social‐ecological outcomes from these potentially interacting behaviors remain under explored. We applied a social‐ecological systems framework using a simulation model and empirical data to determine whether lakeshore development is likely to promote stocking through its adverse effects on coarse woody habitat and thereby also on survival of juvenile and adult fish. We demonstrate that high lakeshore development is likely to generate dependency of the ecosystem on the social system, in the form of stocking. Further, lakeshore development can interact with social‐ecological processes to create deficits for state‐level governments, which threatens the ability to fund further ecosystem subsidies. Our results highlight the value of a social‐ecological framework for maintaining ecosystem services like recreational fisheries.

Development of a 13 kW Hall Thruster Propulsion System Performance Model for AEPS

NASA Technical Reports Server (NTRS)

Stanley, Steven; Allen, May; Goodfellow, Keith; Chew, Gilbert; Rapetti, Ryan; Tofil, Todd; Herman, Dan; Jackson, Jerry; Myers, Roger

2017-01-01

The Advanced Electric Propulsion System (AEPS) program will develop a flight 13kW Hall thruster propulsion system based on NASA's HERMeS thruster. The AEPS system includes the Hall Thruster, the Power Processing Unit (PPU) and the Xenon Flow Controller (XFC). These three primary components must operate together to ensure that the system generates the required combinations of thrust and specific impulse at the required system efficiencies for the desired system lifetime. At the highest level, the AEPS system will be integrated into the spacecraft and will receive power, propellant, and commands from the spacecraft. Power and propellant flow rates will be determined by the throttle set points commanded by the spacecraft. Within the system, the major control loop is between the mass flow rate and thruster current, with time-dependencies required to handle all expected transients, and additional, much slower interactions between the thruster and cathode temperatures, flow controller and PPU. The internal system interactions generally occur on shorter timescales than the spacecraft interactions, though certain failure modes may require rapid responses from the spacecraft. The AEPS system performance model is designed to account for all these interactions in a way that allows evaluation of the sensitivity of the system to expected changes over the planned mission as well as to assess the impacts of normal component and assembly variability during the production phase of the program. This effort describes the plan for the system performance model development, correlation to NASA test data, and how the model will be used to evaluate the critical internal and external interactions. The results will ensure the component requirements do not unnecessarily drive the system cost or overly constrain the development program. Finally, the model will be available to quickly troubleshoot any future unforeseen development challenges.

Ecosystems and the Biosphere as Complex Adaptive Systems

NASA Technical Reports Server (NTRS)

Levin, Simon A.

1998-01-01

Ecosystems are prototypical examples of complex adaptive systems, in which patterns at higher levels emerge from localized interactions and selection processes acting at lower levels. An essential aspect of such systems is nonlinearity, leading to historical dependency and multiple possible outcomes of dynamics. Given this, it is essential to determine the degree to which system features are determined by environmental conditions, and the degree to which they are the result of self-organization. Furthermore, given the multiple levels at which dynamics become apparent and at which selection can act, central issues relate to how evolution shapes ecosystems properties, and whether ecosystems become buffered to changes (more resilient) over their ecological and evolutionary development or proceed to critical states and the edge of chaos.

Controlling nonlinear optical response in an open four-level molecular system using quantum control of spin-orbit interaction

NASA Astrophysics Data System (ADS)

Jamshidi-Ghaleh, Kazem; Ebrahimi-hamed, Zahra; Sahrai, Mostafa

2017-10-01

This paper investigates the behavior of linear and nonlinear optical susceptibility of an open four-level molecular system, under two-step excitation based on electromagnetically induced transparency (EIT). The system was irradiated with a weak probe field and strong coupling field. It is shown that the use of a strong coupling field in the triplet states of an alkali-metal dimer can change the spin-orbit interaction (SOI). The optical response of the system can then be modified in a controllable way. The electromagnetically induced transparency transforms into electromagnetically induced absorption (EIA) in the presence of a coupling field. Changing the sign of the dispersion, this region is associated with switching subluminal and superluminal propagation. Furthermore, for the proper value of the coupling field, the controllable parameters, enhanced Kerr nonlinearity with reduced linear absorption, can be obtained under a weak probe field. With this approach, SOI can be controlled by changing only one of the controllable parameters, using triplet-triplet strong coupling with different spin state. Therefore, the desired region of the spectra can be obtained, in contrast to the other four-level system, in which at least two strong fields are used to change optical properties. This mechanism can be suitable in molecular systems or semiconductors to be used in optical bistability and fast all-optical switching devices.

Steel bridge in interaction with modern slab track fastening systems under various vertical load levels

NASA Astrophysics Data System (ADS)

Stančík, Vojtěch; Ryjáček, Pavel; Vokáč, Miroslav

2017-09-01

In modern slab tracks the continuously welded rail (CWR) is coupled through the fastening system with the substructure. The resulting restriction of expansion movement causes significant rail stress increments, which in the case of extreme loading may cause rail failures. These interaction phenomenon effects are naturally higher on a bridge due to different deformation capabilities of the bridge and the CWR. The presented contribution aims at investigating the state of the art European direct fastening system that is suitable for application on steel bridges. Analysis involves experimental determination of its nonlinear longitudinal interaction parameters under various vertical loads and numerical validation. During experimental procedures a two and a half meter long laboratory sample equipped with four nodes of the Vossloh DFF 300 was tested. There have been checked both DFF 300 modifications using the skl 15 tension clamps and the low resistance skl B15 tension clamps. The effects of clamping force lowering on the interaction parameters have also been investigated. Results are discussed in the paper.

Observation of Tunable Charged Exciton Polaritons in Hybrid Monolayer WS2-Plasmonic Nanoantenna System.

PubMed

Cuadra, Jorge; Baranov, Denis G; Wersäll, Martin; Verre, Ruggero; Antosiewicz, Tomasz J; Shegai, Timur

2018-03-14

Formation of dressed light-matter states in optical structures, manifested as Rabi splitting of the eigen energies of a coupled system, is one of the key effects in quantum optics. In pursuing this regime with semiconductors, light is usually made to interact with excitons, electrically neutral quasiparticles of semiconductors; meanwhile interactions with charged three-particle states, trions, have received little attention. Here, we report on strong interaction between localized surface plasmons in silver nanoprisms and excitons and trions in monolayer tungsten disulfide (WS 2 ). We show that the plasmon-exciton interactions in this system can be efficiently tuned by controlling the charged versus neutral exciton contribution to the coupling process. In particular, we show that a stable trion state emerges and couples efficiently to the plasmon resonance at low temperature by forming three bright intermixed plasmon-exciton-trion polariton states. Our findings open up a possibility to exploit electrically charged polaritons at the single nanoparticle level.

The Nested Systems of Local School Development: Understanding Improved Interaction and Capacities in the Different Sub-Systems of Schools

ERIC Educational Resources Information Center

Adolfsson, Carl-Henrik; Alvunger, Daniel

2017-01-01

In school systems around the world, there is an increasing focus on students' academic achievement. The challenge of how to improve schools is an important issue for all levels in the school system. However, a central question of both practical and theoretical relevance is how it is possible to understand why (or why not) school-development…

Realization of a Quantum Integer-Spin Chain with Controllable Interactions

DTIC Science & Technology

2015-06-17

site participate in the dynamics. We observe the time evolution of the system and verify its coherence by entangling a pair of effective three-level...states generated by the XY Hamiltonian, we can verify entangle - ment between a pair of three-level systems with fidelities of up to 86%. Adding a time...3(b) shows an example of the measured parity curve used to extract the amplitude A and verify entanglement between the qutrit pair . Such measurements

Mutual influences between the main olfactory and vomeronasal systems in development and evolution

PubMed Central

Suárez, Rodrigo; García-González, Diego; de Castro, Fernando

2012-01-01

The sense of smell plays a crucial role in the sensory world of animals. Two chemosensory systems have been traditionally thought to play-independent roles in mammalian olfaction. According to this, the main olfactory system (MOS) specializes in the detection of environmental odorants, while the vomeronasal system (VNS) senses pheromones and semiochemicals produced by individuals of the same or different species. Although both systems differ in their anatomy and function, recent evidence suggests they act synergistically in the perception of scents. These interactions include similar responses to some ligands, overlap of telencephalic connections and mutual influences in the regulation of olfactory-guided behavior. In the present work, we propose the idea that the relationships between systems observed at the organismic level result from a constant interaction during development and reflects a common history of ecological adaptations in evolution. We review the literature to illustrate examples of developmental and evolutionary processes that evidence these interactions and propose that future research integrating both systems may shed new light on the mechanisms of olfaction. PMID:23269914

The Intelligent Transportation Systems Public Safety Program : opportunities for technological advancement in detecting, responding, and recovering from community emergencies

DOT National Transportation Integrated Search

2001-01-01

During the summer and fall of 2000, a group of high level public safety and transportation officials was brought together by the US Department of Transportations (USDOT) Intelligent Transportation Systems (ITS) Program to consider the interaction bet...

Research Methodology on Language Development from a Complex Systems Perspective

ERIC Educational Resources Information Center

Larsen-Freeman, Diane; Cameron, Lynne

2008-01-01

Changes to research methodology motivated by the adoption of a complexity theory perspective on language development are considered. The dynamic, nonlinear, and open nature of complex systems, together with their tendency toward self-organization and interaction across levels and timescales, requires changes in traditional views of the functions…

The Many Forms of Research-Informed Practice: A Framework for Mapping Diversity

ERIC Educational Resources Information Center

Ostinelli, Giorgio

2016-01-01

This article investigates the interaction between educational research and practice in school systems, through a bi-dimensional framework. Forty-four papers were selected and analysed, and were grouped based on their pertinence to the categories: "system level" (macro-meso-micro) and "locus of need"…

uRespond: iPad as Interactive, Personal Response System

ERIC Educational Resources Information Center

Bryfczynski, Samuel P.; Brown, Rebecca; Hester, Josiah; Herrmann, Andrew; Koch, Danielle L.; Cooper, Melanie M.; Grove, Nathaniel P.

2014-01-01

Personal response systems are quickly becoming indispensable formative assessment tools in many college-level chemistry courses. With the use of such devices, students are provided with invaluable insights into the skills perceived by the instructor as important, while concurrently, the instructor can gather feedback as to how well students have…

Alpha-amylase reactivity in relation to psychopathic traits in adults.

PubMed

Glenn, Andrea L; Remmel, Rheanna J; Raine, Adrian; Schug, Robert A; Gao, Yu; Granger, Douglas A

2015-04-01

Recent investigations of the psychobiology of stress in antisocial youth have benefited from a multi-system measurement model. The inclusion of salivary alpha-amylase (sAA), a surrogate marker of autonomic/sympathetic nervous system (ANS) activity, in addition to salivary cortisol, a biomarker of the hypothalamic-pituitary-adrenal (HPA) axis functioning, has helped define a more complete picture of individual differences and potential dysfunction in the stress response system of these individuals. To the authors' knowledge, no studies have examined sAA in relation to antisocial behavior in adults or in relation to psychopathic traits specifically. In the present study, we examined sAA, in addition to salivary cortisol, in a relatively large sample (n=158) of adult males (M age=36.81, range=22-67 years; 44% African-American, 34% Caucasian, 16% Hispanic) recruited from temporary employment agencies with varying levels of psychopathic traits. Males scoring highest in psychopathy were found to have attenuated sAA reactivity to social stress compared to those scoring lower in psychopathy. No differential relationships with the different factors of psychopathy were observed. In contrast to studies of antisocial youth, there were no interactions between sAA and cortisol levels in relation to psychopathy, but there was a significant interaction between pre-stressor levels of sAA and cortisol. Findings reveal potential regulatory deficits in the fast-acting, 'fight or flight', component of the stress response in adult males with psychopathic traits, as well as abnormalities in how this system may interact with the HPA axis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Alpha-Amylase Reactivity in Relation to Psychopathic Traits in Adults

PubMed Central

Glenn, Andrea L.; Remmel, Rheanna J.; Raine, Adrian; Schug, Robert A.; Gao, Yu; Granger, Douglas A.

2015-01-01

Recent investigations of the psychobiology of stress in antisocial youth have benefited from a multi-system measurement model. The inclusion of salivary alpha-amylase (sAA), a surrogate marker of autonomic/sympathetic nervous system (ANS) activity, in addition to salivary cortisol, a biomarker of the hypothalamic-pituitary-adrenal (HPA) axis functioning, has helped define a more complete picture of individual differences and potential dysfunction in the stress response system of these individuals. To the authors' knowledge, no studies have examined sAA in relation to antisocial behavior in adults or in relation to psychopathic traits specifically. In the present study, we examined sAA, in addition to salivary cortisol, in a relatively large sample (n = 158) of adult males (M age = 36.81, range = 22-67 years; 44% African-American, 34% Caucasian, 16% Hispanic) recruited from temporary employment agencies with varying levels of psychopathic traits. Males scoring highest in psychopathy were found to have attenuated sAA reactivity to social stress compared to those scoring lower in psychopathy. No differential relationships with the different factors of psychopathy were observed. In contrast to studies of antisocial youth, there were no interactions between sAA and cortisol levels in relation to psychopathy, but there was a significant interaction between pre-stressor levels of sAA and cortisol. Findings reveal potential regulatory deficits in the fast-acting, ‘fight or flight’, component of the stress response in adult males with psychopathic traits, as well as abnormalities in how this system may interact with the HPA axis. PMID:25662339

[The system-oriented model of psychosocial rehabilitation].

PubMed

Iastrebov V S; Mitikhin, V G; Solokhina, T A; Mikhaĭlova, I I

2008-01-01

A model of psychosocial rehabilitation based on the system approach that allows taking into account both the patient-centered approach of the rehabilitation service, the development of its resource basis, the effectiveness of this care system in whole and its patterns as well has been worked out. In the framework of this model, the authors suggest to single out three basic stages of the psychosocial rehabilitation process: evaluation and planning, rehabilitation interventions per se, achievement of the result. In author's opinion, the most successful way for constructing a modern model of psychosocial rehabilitation is a method of hierarchic modeling which can reveal a complex chain of interactions between all participants of the rehabilitation process and factors involved in this process and at the same time specify the multi-level hierarchic character of these interactions and factors. An important advantage of this method is the possibility of obtaining as static as well dynamic evaluations of the rehabilitation service activity that may be used on the following levels: 1) patient; 2) his/her close environment; 3) macrosocial level. The obvious merits of the system-oriented model appear to be the possibility of application of its principles in the organization of specialized care for psychiatric patients on the local, regional and federal levels. The authors emphasize that hierarchic models have universal character and can be implemented in the elaboration of information-analytical systems aimed at solving the problems of monitoring and analysis of social-medical service activity in order to increase its effectiveness.

Resilience among children and adolescents at risk for depression: Mediation and moderation across social and neurobiological contexts.

PubMed

Silk, Jennifer S; Vanderbilt-Adriance, Ella; Shaw, Daniel S; Forbes, Erika E; Whalen, Diana J; Ryan, Neal D; Dahl, Ronald E

2007-01-01

This article offers a multilevel perspective on resilience to depression, with a focus on interactions among social and neurobehavioral systems involved in emotional reactivity and regulation. We discuss models of cross-contextual mediation and moderation by which the social context influences or modifies the effects of resilience processes at the biological level, or the biological context influences or modifies the effects of resilience processes at the social level. We highlight the socialization of emotion regulation as a candidate process contributing to resilience against depression at the social context level. We discuss several factors and their interactions across levels-including genetic factors, stress reactivity, positive affect, neural systems of reward, and sleep-as candidate processes contributing to resilience against depression at the neurobehavioral level. We then present some preliminary supportive findings from two studies of children and adolescents at high risk for depression. Study 1 shows that elevated neighborhood level adversity has the potential to constrain or limit the benefits of protective factors at other levels. Study 2 indicates that ease and quickness in falling asleep and a greater amount of time in deep Stage 4 sleep may be protective against the development of depressive disorders for children. The paper concludes with a discussion of clinical implications of this approach.

Automated identification of protein-ligand interaction features using Inductive Logic Programming: a hexose binding case study.

PubMed

A Santos, Jose C; Nassif, Houssam; Page, David; Muggleton, Stephen H; E Sternberg, Michael J

2012-07-11

There is a need for automated methods to learn general features of the interactions of a ligand class with its diverse set of protein receptors. An appropriate machine learning approach is Inductive Logic Programming (ILP), which automatically generates comprehensible rules in addition to prediction. The development of ILP systems which can learn rules of the complexity required for studies on protein structure remains a challenge. In this work we use a new ILP system, ProGolem, and demonstrate its performance on learning features of hexose-protein interactions. The rules induced by ProGolem detect interactions mediated by aromatics and by planar-polar residues, in addition to less common features such as the aromatic sandwich. The rules also reveal a previously unreported dependency for residues cys and leu. They also specify interactions involving aromatic and hydrogen bonding residues. This paper shows that Inductive Logic Programming implemented in ProGolem can derive rules giving structural features of protein/ligand interactions. Several of these rules are consistent with descriptions in the literature. In addition to confirming literature results, ProGolem's model has a 10-fold cross-validated predictive accuracy that is superior, at the 95% confidence level, to another ILP system previously used to study protein/hexose interactions and is comparable with state-of-the-art statistical learners.

Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform

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

Williams, Tess L.; Fuller, Jason C.; Schneider, Kevin P.

2014-10-11

High penetration levels of distributed solar PV power generation can lead to adverse power quality impacts such as excessive voltage rise, voltage flicker, and reactive power values that result in unacceptable voltage levels. Advanced inverter control schemes have been proposed that have the potential to mitigate many power quality concerns. However, closed-loop control may lead to unintended behavior in deployed systems as complex interactions can occur between numerous operating devices. In order to enable the study of the performance of advanced control schemes in a detailed distribution system environment, a Hardware-in-the-Loop (HIL) platform has been developed. In the HIL system,more » GridLAB-D, a distribution system simulation tool, runs in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling to hardware located at the National Renewable Energy Laboratory (NREL). Hardware inverters interact with grid and PV simulators emulating an operational distribution system and power output from the inverters is measured and sent to PNNL to update the real-time distribution system simulation. The platform is described and initial test cases are presented. The platform is used to study the system-wide impacts and the interactions of controls applied to inverters that are integrated into a simulation of the IEEE 8500-node test feeder, with inverters in either constant power factor control or active volt/VAR control. We demonstrate that this HIL platform is well-suited to the study of advanced inverter controls and their impacts on the power quality of a distribution feeder. Additionally, the results from HIL are used to validate GridLAB-D simulations of advanced inverter controls.« less

Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform

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

Williams, Tess L.; Fuller, Jason C.; Schneider, Kevin P.

2014-06-08

High penetration levels of distributed solar PV power generation can lead to adverse power quality impacts, such as excessive voltage rise, voltage flicker, and reactive power values that result in unacceptable voltage levels. Advanced inverter control schemes have been developed that have the potential to mitigate many power quality concerns. However, local closed-loop control may lead to unintended behavior in deployed systems as complex interactions can occur between numerous operating devices. To enable the study of the performance of advanced control schemes in a detailed distribution system environment, a test platform has been developed that integrates Power Hardware-in-the-Loop (PHIL) withmore » concurrent time-series electric distribution system simulation. In the test platform, GridLAB-D, a distribution system simulation tool, runs a detailed simulation of a distribution feeder in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling. At the National Renewable Energy Laboratory (NREL), a hardware inverter interacts with grid and PV simulators emulating an operational distribution system. Power output from the inverters is measured and sent to PNNL to update the real-time distribution system simulation. The platform is described and initial test cases are presented. The platform is used to study the system-wide impacts and the interactions of inverter control modes—constant power factor and active Volt/VAr control—when integrated into a simulated IEEE 8500-node test feeder. We demonstrate that this platform is well-suited to the study of advanced inverter controls and their impacts on the power quality of a distribution feeder. Additionally, results are used to validate GridLAB-D simulations of advanced inverter controls.« less

An interactive visualization tool for mobile objects

NASA Astrophysics Data System (ADS)

Kobayashi, Tetsuo

Recent advancements in mobile devices---such as Global Positioning System (GPS), cellular phones, car navigation system, and radio-frequency identification (RFID)---have greatly influenced the nature and volume of data about individual-based movement in space and time. Due to the prevalence of mobile devices, vast amounts of mobile objects data are being produced and stored in databases, overwhelming the capacity of traditional spatial analytical methods. There is a growing need for discovering unexpected patterns, trends, and relationships that are hidden in the massive mobile objects data. Geographic visualization (GVis) and knowledge discovery in databases (KDD) are two major research fields that are associated with knowledge discovery and construction. Their major research challenges are the integration of GVis and KDD, enhancing the ability to handle large volume mobile objects data, and high interactivity between the computer and users of GVis and KDD tools. This dissertation proposes a visualization toolkit to enable highly interactive visual data exploration for mobile objects datasets. Vector algebraic representation and online analytical processing (OLAP) are utilized for managing and querying the mobile object data to accomplish high interactivity of the visualization tool. In addition, reconstructing trajectories at user-defined levels of temporal granularity with time aggregation methods allows exploration of the individual objects at different levels of movement generality. At a given level of generality, individual paths can be combined into synthetic summary paths based on three similarity measures, namely, locational similarity, directional similarity, and geometric similarity functions. A visualization toolkit based on the space-time cube concept exploits these functionalities to create a user-interactive environment for exploring mobile objects data. Furthermore, the characteristics of visualized trajectories are exported to be utilized for data mining, which leads to the integration of GVis and KDD. Case studies using three movement datasets (personal travel data survey in Lexington, Kentucky, wild chicken movement data in Thailand, and self-tracking data in Utah) demonstrate the potential of the system to extract meaningful patterns from the otherwise difficult to comprehend collections of space-time trajectories.

Pharmacogenomics Implications of Using Herbal Medicinal Plants on African Populations in Health Transition

PubMed Central

Thomford, Nicholas E.; Dzobo, Kevin; Chopera, Denis; Wonkam, Ambroise; Skelton, Michelle; Blackhurst, Dee; Chirikure, Shadreck; Dandara, Collet

2015-01-01

The most accessible points of call for most African populations with respect to primary health care are traditional health systems that include spiritual, religious, and herbal medicine. This review focusses only on the use of herbal medicines. Most African people accept herbal medicines as generally safe with no serious adverse effects. However, the overlap between conventional medicine and herbal medicine is a reality among countries in health systems transition. Patients often simultaneously seek treatment from both conventional and traditional health systems for the same condition. Commonly encountered conditions/diseases include malaria, HIV/AIDS, hypertension, tuberculosis, and bleeding disorders. It is therefore imperative to understand the modes of interaction between different drugs from conventional and traditional health care systems when used in treatment combinations. Both conventional and traditional drug entities are metabolized by the same enzyme systems in the human body, resulting in both pharmacokinetics and pharmacodynamics interactions, whose properties remain unknown/unquantified. Thus, it is important that profiles of interaction between different herbal and conventional medicines be evaluated. This review evaluates herbal and conventional drugs in a few African countries and their potential interaction at the pharmacogenomics level. PMID:26402689

Phase transition of light in cavity QED lattices.

PubMed

Schiró, M; Bordyuh, M; Oztop, B; Türeci, H E

2012-08-03

Systems of strongly interacting atoms and photons, which can be realized wiring up individual cavity QED systems into lattices, are perceived as a new platform for quantum simulation. While sharing important properties with other systems of interacting quantum particles, here we argue that the nature of light-matter interaction gives rise to unique features with no analogs in condensed matter or atomic physics setups. By discussing the physics of a lattice model of delocalized photons coupled locally with two-level systems through the elementary light-matter interaction described by the Rabi model, we argue that the inclusion of counterrotating terms, so far neglected, is crucial to stabilize finite-density quantum phases of correlated photons out of the vacuum, with no need for an artificially engineered chemical potential. We show that the competition between photon delocalization and Rabi nonlinearity drives the system across a novel Z(2) parity symmetry-breaking quantum criticality between two gapped phases that share similarities with the Dicke transition of quantum optics and the Ising critical point of quantum magnetism. We discuss the phase diagram as well as the low-energy excitation spectrum and present analytic estimates for critical quantities.

Phase time delay and Hartman effect in a one-dimensional photonic crystal with four-level atomic defect layer

NASA Astrophysics Data System (ADS)

Jamil, Rabia; Ali, Abu Bakar; Abbas, Muqaddar; Badshah, Fazal; Qamar, Sajid

2017-08-01

The Hartman effect is revisited using a Gaussian beam incident on a one-dimensional photonic crystal (1DPC) having a defect layer doped with four-level atoms. It is considered that each atom of the defect layer interacts with three driving fields, whereas a Gaussian beam of width w is used as a probe light to study Hartman effect. The atom-field interaction inside the defect layer exhibits electromagnetically induced transparency (EIT). The 1DPC acts as positive index material (PIM) and negative index material (NIM) corresponding to the normal and anomalous dispersion of the defect layer, respectively, via control of the phase associated with the driving fields and probe detuning. The positive and negative Hartman effects are noticed for PIM and NIM, respectively, via control of the relative phase corresponding to the driving fields and probe detuning. The advantage of using four-level EIT system is that a much smaller absorption of the transmitted beam occurs as compared to three-level EIT system corresponding to the anomalous dispersion, leading to negative Hartman effect.

Dynamics of entropy and nonclassical properties of the state of a Λ-type three-level atom interacting with a single-mode cavity field with intensity-dependent coupling in a Kerr medium

NASA Astrophysics Data System (ADS)

Faghihi, M. J.; Tavassoly, M. K.

2012-02-01

In this paper, we study the interaction between a three-level atom and a quantized single-mode field with ‘intensity-dependent coupling’ in a ‘Kerr medium’. The three-level atom is considered to be in a Λ-type configuration. Under particular initial conditions, which may be prepared for the atom and the field, the dynamical state vector of the entire system will be explicitly obtained, for the arbitrary nonlinearity function f(n) associated with any physical system. Then, after evaluating the variation of the field entropy against time, we will investigate the quantum statistics as well as some of the nonclassical properties of the introduced state. During our calculations we investigate the effects of intensity-dependent coupling, Kerr medium and detuning parameters on the depth and domain of the nonclassicality features of the atom-field state vector. Finally, we compare our obtained results with those of V-type three-level atoms.

Alpha-synuclein mitochondrial interaction leads to irreversible translocation and complex I impairment.

PubMed

Martínez, Jimena H; Fuentes, Federico; Vanasco, Virginia; Alvarez, Silvia; Alaimo, Agustina; Cassina, Adriana; Coluccio Leskow, Federico; Velazquez, Francisco

2018-08-01

α-synuclein is involved in both familial and sporadic Parkinson's disease. Although its interaction with mitochondria has been well documented, several aspects remains unknown or under debate such as the specific sub-mitochondrial localization or the dynamics of the interaction. It has been suggested that α-synuclein could only interact with ER-associated mitochondria. The vast use of model systems and experimental conditions makes difficult to compare results and extract definitive conclusions. Here we tackle this by analyzing, in a simplified system, the interaction between purified α-synuclein and isolated rat brain mitochondria. This work shows that wild type α-synuclein interacts with isolated mitochondria and translocates into the mitochondrial matrix. This interaction and the irreversibility of α-synuclein translocation depend on incubation time and α-synuclein concentration. FRET experiments show that α-synuclein localizes close to components of the TOM complex suggesting a passive transport of α-synuclein through the outer membrane. In addition, α-synuclein binding alters mitochondrial function at the level of Complex I leading to a decrease in ATP synthesis and an increase of ROS production. Copyright © 2018. Published by Elsevier Inc.

Is health workforce planning recognising the dynamic interplay between health literacy at an individual, organisation and system level?

PubMed

Naccarella, Lucio; Wraight, Brenda; Gorman, Des

2016-02-01

The growing demands on the health system to adapt to constant change has led to investment in health workforce planning agencies and approaches. Health workforce planning approaches focusing on identifying, predicting and modelling workforce supply and demand are criticised as being simplistic and not contributing to system-level resiliency. Alternative evidence- and needs-based health workforce planning approaches are being suggested. However, to contribute to system-level resiliency, workforce planning approaches need to also adopt system-based approaches. The increased complexity and fragmentation of the healthcare system, especially for patients with complex and chronic conditions, has also led to a focus on health literacy not simply as an individual trait, but also as a dynamic product of the interaction between individual (patients, workforce)-, organisational- and system-level health literacy. Although it is absolutely essential that patients have a level of health literacy that enables them to navigate and make decisions, so too the health workforce, organisations and indeed the system also needs to be health literate. Herein we explore whether health workforce planning is recognising the dynamic interplay between health literacy at an individual, organisation and system level, and the potential for strengthening resiliency across all those levels.

Pulsed Rabi oscillations in quantum two-level systems: beyond the area theorem

NASA Astrophysics Data System (ADS)

Fischer, Kevin A.; Hanschke, Lukas; Kremser, Malte; Finley, Jonathan J.; Müller, Kai; Vučković, Jelena

2018-01-01

The area theorem states that when a short optical pulse drives a quantum two-level system, it undergoes Rabi oscillations in the probability of scattering a single photon. In this work, we investigate the breakdown of the area theorem as both the pulse length becomes non-negligible and for certain pulse areas. Using simple quantum trajectories, we provide an analytic approximation to the photon emission dynamics of a two-level system. Our model provides an intuitive way to understand re-excitation, which elucidates the mechanism behind the two-photon emission events that can spoil single-photon emission. We experimentally measure the emission statistics from a semiconductor quantum dot, acting as a two-level system, and show good agreement with our simple model for short pulses. Additionally, the model clearly explains our recent results (Fischer and Hanschke 2017 et al Nat. Phys.) showing dominant two-photon emission from a two-level system for pulses with interaction areas equal to an even multiple of π.

Dirac oscillator interacting with a topological defect

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

Carvalho, J.; Furtado, C.; Moraes, F.

In this work we study the interaction problem of a Dirac oscillator with gravitational fields produced by topological defects. The energy levels of the relativistic oscillator in the cosmic string and in the cosmic dislocation space-times are sensible to curvature and torsion associated to these defects and are important evidence of the influence of the topology on this system. In the presence of a localized magnetic field the energy levels acquire a term associated with the Aharonov-Bohm effect. We obtain the eigenfunctions and eigenvalues and see that in the nonrelativistic limit some results known in standard quantum mechanics are reached.

State-of-the-art Hydrology Education: Development of Windows-based and Web-based Interactive Teaching-Learning Software

NASA Astrophysics Data System (ADS)

Chu, X.

2011-12-01

This study, funded by the NSF CAREER program, focuses on developing new methods to quantify microtopography-controlled overland flow processes and integrating the cutting-edge hydrologic research with all-level education and outreach activities. To achieve the educational goal, an interactive teaching-learning software package has been developed. This software, with enhanced visualization capabilities, integrates the new modeling techniques, computer-guided learning processes, and education-oriented tools in a user-friendly interface. Both Windows-based and web-based versions have been developed. The software is specially designed for three major user levels: elementary level (Level 1: K-12 and outreach education), medium level (Level 2: undergraduate education), and advanced level (Level 3: graduate education). Depending on the levels, users are guided to different educational systems. Each system consists of a series of mini "libraries" featured with movies, pictures, and documentation that cover fundamental theories, varying scale experiments, and computer modeling of overland flow generation, surface runoff, and infiltration processes. Testing and practical use of this educational software in undergraduate and graduate teaching demonstrate its effectiveness to promote students' learning and interest in hydrologic sciences. This educational software also has been used as a hydrologic demonstration tool for K-12 students and Native American students through the Nurturing American Tribal Undergraduate Research Education (NATURE) program and Science, Technology, Engineering and Mathematics (STEM) outreach activities.

Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system.

PubMed

Hicks, Natalie; Bulling, Mark T; Solan, Martin; Raffaelli, Dave; White, Piran C L; Paterson, David M

2011-02-14

Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO(2) concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor) in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness. The effects of elevated CO(2) concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity. Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore, these effects would be sufficient to affect the net metabolic balance of the coastal ecosystem, with important implications for system ecology and sustainable exploitation.

An analytical solution of groundwater level fluctuation in a U-shaped leaky coastal aquifer

NASA Astrophysics Data System (ADS)

Huang, Fu-Kuo; Chuang, Mo-Hsiung; Wang, Shu-chuan

2017-04-01

Tide-induced groundwater level fluctuations in coastal aquifers have attracted much attention in past years, especially for the issues associated with the impact of the coastline shape, multi-layered leaky aquifer system, and anisotropy of aquifers. In this study, a homogeneous but anisotropic multi-layered leaky aquifer system with U-shaped coastline is considered, where the subsurface system consisting of an unconfined aquifer, a leaky confined aquifer, and a semi-permeable layer between them. The analytical solution of the model obtained herein may be considered as an extended work of two solutions; one was developed by Huang et al. (Huang et al. Tide-induced groundwater level fluctuation in a U-shaped coastal aquifer, J. Hydrol. 2015; 530: 291-305) for two-dimensional interacting tidal waves bounded by three water-land boundaries while the other was by Li and Jiao (Li and Jiao. Tidal groundwater level fluctuations in L-shaped leaky coastal aquifer system, J. Hydrol. 2002; 268: 234-243) for two-dimensional interacting tidal waves of leaky coastal aquifer system adjacent to a cross-shore estuary. In this research, the effects of leakage and storativity of the semi-permeable layer on the amplitude and phase shift of the tidal head fluctuation, and the influence of anisotropy of the aquifer are all examined for the U-shaped leaky coastal aquifer. Some existing solutions in literatures can be regarded as the special cases of the present solution if the aquifer system is isotropic and non-leaky. The results obtained will be beneficial to coastal development and management for water resources.

The sensory interactions of organic acids and various flavors in ramen soup systems.

PubMed

Kang, M-W; Chung, S-J; Lee, H-S; Kim, Y; Kim, K-O

2007-11-01

This study was conducted to investigate the sensory interactions between various organic acids and flavorants in 3 types of ramen soup ('beef,' seafood, and 'kimchi') when types and levels of organic acids (citric, malic, and lactic) varied. For 'beef' and seafood ramen soup, weak suprathreshold levels of acids (0.0039% to 0.0071%) were applied to the system and medium suprathreshold of acids (0.0128% to 0.0299%) were applied to the kimchi ramen soup. The amount of acid applied to each system was chosen based on the equiweight level. Descriptive analyses were performed separately for each ramen soup system using 8 trained panelists. A total of 11, 13, and 12 flavor descriptors were generated for 'beef,' seafood, and 'kimchi' soup, respectively. Analysis of variance was conducted to evaluate the effect of organic acid on the sensory characteristics of ramen soup. Principal component analysis was conducted to summarize the relationship between the soup samples and attributes. The effect of organic acids on the flavor attributes of ramen soup was dependent on the soup system as well as adding levels of acid. Addition of lactic acid power (at 0.0066%) in 'beef'ramen soup showed enhancement effect on the sour, salty, beefy, 'mushroom' flavor, and fermented soybean paste soup flavor, whereas lactic acid powder (at 0.0071%) showed enhancement effect only on the sour and fermented soybean paste soup flavor in seafood ramen soup due to the strong 'hot' flavor characteristics of the soup. In kimchi ramen soup, flavor attributes congruent to sourness were enhanced by the addition of organic acids to the system.

Exploring the bases for a mixed reality stroke rehabilitation system, Part II: design of interactive feedback for upper limb rehabilitation.

PubMed

Lehrer, Nicole; Chen, Yinpeng; Duff, Margaret; L Wolf, Steven; Rikakis, Thanassis

2011-09-08

Few existing interactive rehabilitation systems can effectively communicate multiple aspects of movement performance simultaneously, in a manner that appropriately adapts across various training scenarios. In order to address the need for such systems within stroke rehabilitation training, a unified approach for designing interactive systems for upper limb rehabilitation of stroke survivors has been developed and applied for the implementation of an Adaptive Mixed Reality Rehabilitation (AMRR) System. The AMRR system provides computational evaluation and multimedia feedback for the upper limb rehabilitation of stroke survivors. A participant's movements are tracked by motion capture technology and evaluated by computational means. The resulting data are used to generate interactive media-based feedback that communicates to the participant detailed, intuitive evaluations of his performance. This article describes how the AMRR system's interactive feedback is designed to address specific movement challenges faced by stroke survivors. Multimedia examples are provided to illustrate each feedback component. Supportive data are provided for three participants of varying impairment levels to demonstrate the system's ability to train both targeted and integrated aspects of movement. The AMRR system supports training of multiple movement aspects together or in isolation, within adaptable sequences, through cohesive feedback that is based on formalized compositional design principles. From preliminary analysis of the data, we infer that the system's ability to train multiple foci together or in isolation in adaptable sequences, utilizing appropriately designed feedback, can lead to functional improvement. The evaluation and feedback frameworks established within the AMRR system will be applied to the development of a novel home-based system to provide an engaging yet low-cost extension of training for longer periods of time.

Exploring the bases for a mixed reality stroke rehabilitation system, Part II: Design of Interactive Feedback for upper limb rehabilitation

PubMed Central

2011-01-01

Background Few existing interactive rehabilitation systems can effectively communicate multiple aspects of movement performance simultaneously, in a manner that appropriately adapts across various training scenarios. In order to address the need for such systems within stroke rehabilitation training, a unified approach for designing interactive systems for upper limb rehabilitation of stroke survivors has been developed and applied for the implementation of an Adaptive Mixed Reality Rehabilitation (AMRR) System. Results The AMRR system provides computational evaluation and multimedia feedback for the upper limb rehabilitation of stroke survivors. A participant's movements are tracked by motion capture technology and evaluated by computational means. The resulting data are used to generate interactive media-based feedback that communicates to the participant detailed, intuitive evaluations of his performance. This article describes how the AMRR system's interactive feedback is designed to address specific movement challenges faced by stroke survivors. Multimedia examples are provided to illustrate each feedback component. Supportive data are provided for three participants of varying impairment levels to demonstrate the system's ability to train both targeted and integrated aspects of movement. Conclusions The AMRR system supports training of multiple movement aspects together or in isolation, within adaptable sequences, through cohesive feedback that is based on formalized compositional design principles. From preliminary analysis of the data, we infer that the system's ability to train multiple foci together or in isolation in adaptable sequences, utilizing appropriately designed feedback, can lead to functional improvement. The evaluation and feedback frameworks established within the AMRR system will be applied to the development of a novel home-based system to provide an engaging yet low-cost extension of training for longer periods of time. PMID:21899779

Multiphoton Coherent Manipulation in Large-Spin Qubits

NASA Astrophysics Data System (ADS)

Bertaina, S.; Chen, L.; Groll, N.; van Tol, J.; Dalal, N. S.; Chiorescu, I.

2009-02-01

Large-spin Mn2+ ions (S=5/2) diluted in a nonmagnetic MgO matrix of high crystalline symmetry are used to realize a six-level system that can be operated by means of multiphoton coherent Rabi oscillations. This spin system has a very small anisotropy which can be tuned in situ to reversibly transform the system between harmonic and nonharmonic level configurations. Decoherence effects are strongly suppressed as a result of the quasi-isotropic electron interaction with the crystal field and with the Mn55 nuclear spins. These results suggest new ways of manipulating, reading, and resetting spin quantum states which can be applied to encode a qubit across several quantum levels.

Toward a multiscale modeling framework for understanding serotonergic function

PubMed Central

Wong-Lin, KongFatt; Wang, Da-Hui; Moustafa, Ahmed A; Cohen, Jeremiah Y; Nakamura, Kae

2017-01-01

Despite its importance in regulating emotion and mental wellbeing, the complex structure and function of the serotonergic system present formidable challenges toward understanding its mechanisms. In this paper, we review studies investigating the interactions between serotonergic and related brain systems and their behavior at multiple scales, with a focus on biologically-based computational modeling. We first discuss serotonergic intracellular signaling and neuronal excitability, followed by neuronal circuit and systems levels. At each level of organization, we will discuss the experimental work accompanied by related computational modeling work. We then suggest that a multiscale modeling approach that integrates the various levels of neurobiological organization could potentially transform the way we understand the complex functions associated with serotonin. PMID:28417684

Impact of jamming on collective cell migration

NASA Astrophysics Data System (ADS)

Nnetu, Kenechukwu David; Knorr, Melanie; Pawlizak, Steve; Fuhs, Thomas; Zink, Mareike; KäS, Josef A.

2012-02-01

Multi-cellular migration plays an important role in physiological processes such as embryogenesis, cancer metastasis and tissue repair. During migration, single cells undergo cycles of extension, adhesion and retraction resulting in morphological changes. In a confluent monolayer, there are inter-cellular interactions and crowding, however, the impact of these interactions on the dynamics and elasticity of the monolayer at the multi-cellular and single cell level is not well understood. Here we study the dynamics of a confluent epithelial monolayer by simultaneously measuring cell motion at the multi-cellular and single cell level for various cell densities and tensile elasticity. At the multi-cellular level, the system exhibited spatial kinetic transitions from isotropic to anisotropic migration on long times and the velocity of the monolayer decreased with increasing cell density. Moreover, the dynamics was spatially and temporally heterogeneous. Interestingly, the dynamics was also heterogeneous in wound-healing assays and the correlation length was fitted by compressed exponential. On the single cell scale, we observed transient caging effects with increasing cage rearrangement times as the system age due to an increase in density. Also, the density dependent elastic modulus of the monolayer scaled as a weak power law. Together, these findings suggest that caging effects at the single cell level initiates a slow and heterogeneous dynamics at the multi-cellular level which is similar to the glassy dynamics of deformable colloidal systems.

Talking to your car can drive you to distraction.

PubMed

Strayer, David L; Cooper, Joel M; Turrill, Jonna; Coleman, James R; Hopman, Rachel J

2016-01-01

This research examined the impact of in-vehicle information system (IVIS) interactions on the driver's cognitive workload; 257 subjects participated in a weeklong evaluation of the IVIS interaction in one of ten different model-year 2015 automobiles. After an initial assessment of the cognitive workload associated with using the IVIS, participants took the vehicle home for 5 days and practiced using the system. At the end of the 5 days of practice, participants returned and the workload of these IVIS interactions was reassessed. The cognitive workload was found to be moderate to high, averaging 3.34 on a 5-point scale and ranged from 2.37 to 4.57. The workload was associated with the intuitiveness and complexity of the system and the time it took participants to complete the interaction. The workload experienced by older drivers was significantly greater than that experienced by younger drivers performing the same operations. Practice did not eliminate the interference from IVIS interactions. In fact, IVIS interactions that were difficult on the first day were still relatively difficult to perform after a week of practice. Finally, there were long-lasting residual costs after the IVIS interactions had terminated. The higher levels of workload should serve as a caution that these voice-based interactions can be cognitively demanding and ought not to be used indiscriminately while operating a motor vehicle.

A dual-light reporter system to determine the efficiency of protein–protein interactions in mammalian cells

PubMed Central

Nasim, M. T.; Trembath, R. C.

2005-01-01

Methods for determining protein–protein interactions in mammalian cells typically rely on single reporter functions and are susceptible to variations between samples particularly in regard to levels of transcription, processing and translation. A method has been developed for determining protein–protein interactions in mammalian cells, which bypasses these variables confounding single reporter assays. The approach utilizes two units of gene expression linked to reporter functions that are interposed by a deactivation–activation unit in such a way that the downstream expression unit is switched off. Hence upstream expression occurs regardless of protein–protein interaction, leading to the production of the upstream reporter. In the event of protein–protein interactions, the downstream expression unit is switched on leading to dual reporter read outs. Thus, the ratio of the two reporter activities provides a measure to determine the efficiency of protein–protein interactions. To access the system we screened a mutant of BMPR2 where the interaction between BMPR-II and LIMK is abrogated. BMPR-II is a type II receptor of the TGFβ superfamily and plays a key role in the pathogenesis of familial pulmonary arterial hypertension. This system has potential for high-throughput screening of libraries (peptide, chemical, cDNA, etc.) to isolate agents that are capable of interfering with highly selective protein–protein interaction. PMID:15824058

Potential drug-drug interactions between anti-cancer agents and community pharmacy dispensed drugs.

PubMed

Voll, Marsha L; Yap, Kim D; Terpstra, Wim E; Crul, Mirjam

2010-10-01

To identify the prevalence of potential drug-drug interactions between hospital pharmacy dispensed anti-cancer agents and community pharmacy dispensed drugs. A retrospective cohort study was conducted on the haematology/oncology department of the internal medicine ward in a large teaching hospital in Amsterdam, the Netherlands. Prescription data from the last 100 patients treated with anti-cancer agents were obtained from Paracelsus, the chemotherapy prescribing system in the hospital. The community pharmacy dispensed drugs of these patients were obtained by using OZIS, a system that allows regionally linked pharmacies to call up active medication on any patient. Both medication lists were manually screened for potential drug-drug interactions by using several information sources on interactions, e.g. Pubmed, the Flockhart P450 table, Micromedex and Dutch reference books. Prevalence of potential drug-drug interactions between anti-cancer agents provided by the hospital pharmacy and drugs dispensed by the community pharmacy. Ninety-one patients were included in the study. A total of 31 potential drug-drug interactions were found in 16 patients, of which 15 interactions were clinically relevant and would have required an intervention. Of these interactions 1 had a level of severity ≥ D, meaning the potential drug-drug interaction could lead to long lasting or permanent damage, or even death. The majority of the interactions requiring an intervention (67%) had a considerable level of evidence (≥ 2) and were based on well-documented case reports or controlled interaction studies. Most of the potential drug-drug interactions involved the antiretroviral drugs (40%), proton pump inhibitors (20%) and antibiotics (20%). The anti-cancer drug most involved in the drug-drug interactions is methotrexate (33%). This study reveals a high prevalence of potential drug-drug interactions between anti-cancer agents provided by the hospital pharmacy and drugs dispensed by the community pharmacy. It shows us there is need for an optimal medication surveillance mechanism to detect potential drug-drug interactions between these two groups of medication, especially because of the high toxicity of anticancer drugs and thus the severe consequences these interactions can have for the patient.

Multi-level systems modeling and optimization for novel aircraft

NASA Astrophysics Data System (ADS)

Subramanian, Shreyas Vathul

This research combines the disciplines of system-of-systems (SoS) modeling, platform-based design, optimization and evolving design spaces to achieve a novel capability for designing solutions to key aeronautical mission challenges. A central innovation in this approach is the confluence of multi-level modeling (from sub-systems to the aircraft system to aeronautical system-of-systems) in a way that coordinates the appropriate problem formulations at each level and enables parametric search in design libraries for solutions that satisfy level-specific objectives. The work here addresses the topic of SoS optimization and discusses problem formulation, solution strategy, the need for new algorithms that address special features of this problem type, and also demonstrates these concepts using two example application problems - a surveillance UAV swarm problem, and the design of noise optimal aircraft and approach procedures. This topic is critical since most new capabilities in aeronautics will be provided not just by a single air vehicle, but by aeronautical Systems of Systems (SoS). At the same time, many new aircraft concepts are pressing the boundaries of cyber-physical complexity through the myriad of dynamic and adaptive sub-systems that are rising up the TRL (Technology Readiness Level) scale. This compositional approach is envisioned to be active at three levels: validated sub-systems are integrated to form conceptual aircraft, which are further connected with others to perform a challenging mission capability at the SoS level. While these multiple levels represent layers of physical abstraction, each discipline is associated with tools of varying fidelity forming strata of 'analysis abstraction'. Further, the design (composition) will be guided by a suitable hierarchical complexity metric formulated for the management of complexity in both the problem (as part of the generative procedure and selection of fidelity level) and the product (i.e., is the mission best achieved via a large collection of interacting simple systems, or a relatively few highly capable, complex air vehicles). The vastly unexplored area of optimization in evolving design spaces will be studied and incorporated into the SoS optimization framework. We envision a framework that resembles a multi-level, mult-fidelity, multi-disciplinary assemblage of optimization problems. The challenge is not simply one of scaling up to a new level (the SoS), but recognizing that the aircraft sub-systems and the integrated vehicle are now intensely cyber-physical, with hardware and software components interacting in complex ways that give rise to new and improved capabilities. The work presented here is a step closer to modeling the information flow that exists in realistic SoS optimization problems between sub-contractors, contractors and the SoS architect.

High-throughput analysis of peptide binding modules

PubMed Central

Liu, Bernard A.; Engelmann, Brett; Nash, Piers D.

2014-01-01

Modular protein interaction domains that recognize linear peptide motifs are found in hundreds of proteins within the human genome. Some protein interaction domains such as SH2, 14-3-3, Chromo and Bromo domains serve to recognize post-translational modification of amino acids (such as phosphorylation, acetylation, methylation etc.) and translate these into discrete cellular responses. Other modules such as SH3 and PDZ domains recognize linear peptide epitopes and serve to organize protein complexes based on localization and regions of elevated concentration. In both cases, the ability to nucleate specific signaling complexes is in large part dependent on the selectivity of a given protein module for its cognate peptide ligand. High throughput analysis of peptide-binding domains by peptide or protein arrays, phage display, mass spectrometry or other HTP techniques provides new insight into the potential protein-protein interactions prescribed by individual or even whole families of modules. Systems level analyses have also promoted a deeper understanding of the underlying principles that govern selective protein-protein interactions and how selectivity evolves. Lastly, there is a growing appreciation for the limitations and potential pitfalls of high-throughput analysis of protein-peptide interactomes. This review will examine some of the common approaches utilized for large-scale studies of protein interaction domains and suggest a set of standards for the analysis and validation of datasets from large-scale studies of peptide-binding modules. We will also highlight how data from large-scale studies of modular interaction domain families can provide insight into systems level properties such as the linguistics of selective interactions. PMID:22610655

Integrating Social Science, Environmental Science, and Engineering to Understand Vulnerability and Resilience to Environmental Hazards in the Bengal Delta

NASA Astrophysics Data System (ADS)

Gilligan, J. M.; Ackerly, B.; Goodbred, S. L.

2013-12-01

In populated delta environments, it is impossible to separate human and natural systems. Human activities change the landscape by altering the dynamics of water and sediment and in return, humans themselves are affected by the natural and anthropogenic changes to the landscape. Such interactions can also have significant impacts on the ecology and natural resources of a delta system, affecting local and regional food supply, livelihoods, and economies, particularly in developing nations. Successful adaptation to environmental change in a strongly coupled human-natural system, such as the Bengal delta, requires understanding how the physical environment and the changing social, political, and economic conditions of people's lives interact. Research on human-delta interactions has largely focused on macro-scale effects from major dams, water diversions, and catchment-scale land use; but at the smaller scale of households and communities, decisions, actions, and outcomes may occur abruptly and have significant local impacts (positive or negative). Southwest Bangladesh experiences profound environmental problems at the local human-landscape interface, including groundwater salinity, soil fertility, conflicting land-use practices, management of engineering structures, and declining land-surface elevations. The impacts of climate-induced sea-level rise, especially with respect to population migration, receive great attention and concern, but neither sea level rise nor migration occurs against a background of static physical or human environments. For example, changing land use (e.g., building embankments, which affect drainage, sediment transport, and the evolution of tidal channels; and the transformation of rice fields to shrimp aquaculture, which affects soil chemistry, labor markets, river ecology, and possibly the integrity of embankments) can significantly change the impact that sea level rise will have on flood hazards and the resulting effect on people living on the delta. Assessing the impacts of climate change and other environmental stresses on delta populations and designing effective responses will require understanding interactions between the physical and human environments at multiple scales. As part of a multidisciplinary research project drawing on sedimentology, hydrology, remote-sensing, engineering, political science, sociology, psychology, and anthropology we are studying the interactions of human and natural systems in coastal Bangladesh to understand conditions that contribute to vulnerability and resilience at both the household and the community level. Building on Elinor Ostrom's socioecological systems approach, we have developed a theoretical framework for studying vulnerability and resilience when coupled human-natural systems are subject to significant changes and exogenous forcings. We will report on this framework using examples of successful and unsuccessful interventions to manage or mitigate exposure to environmental hazards, and we will also report on progress toward using our framework to identify and understand factors that contribute to the success or failure of such projects.

Evaluating Multiple Levels of an Interaction Fidelity Continuum on Performance and Learning in Near-Field Training Simulations.

PubMed

Bhargava, Ayush; Bertrand, Jeffrey W; Gramopadhye, Anand K; Madathil, Kapil C; Babu, Sabarish V

2018-04-01

With costs of head-mounted displays (HMDs) and tracking technology decreasing rapidly, various virtual reality applications are being widely adopted for education and training. Hardware advancements have enabled replication of real-world interactions in virtual environments to a large extent, paving the way for commercial grade applications that provide a safe and risk-free training environment at a fraction of the cost. But this also mandates the need to develop more intrinsic interaction techniques and to empirically evaluate them in a more comprehensive manner. Although there exists a body of previous research that examines the benefits of selected levels of interaction fidelity on performance, few studies have investigated the constituent components of fidelity in a Interaction Fidelity Continuum (IFC) with several system instances and their respective effects on performance and learning in the context of a real-world skills training application. Our work describes a large between-subjects investigation conducted over several years that utilizes bimanual interaction metaphors at six discrete levels of interaction fidelity to teach basic precision metrology concepts in a near-field spatial interaction task in VR. A combined analysis performed on the data compares and contrasts the six different conditions and their overall effects on performance and learning outcomes, eliciting patterns in the results between the discrete application points on the IFC. With respect to some performance variables, results indicate that simpler restrictive interaction metaphors and highest fidelity metaphors perform better than medium fidelity interaction metaphors. In light of these results, a set of general guidelines are created for developers of spatial interaction metaphors in immersive virtual environments for precise fine-motor skills training simulations.

Interaction of oxygen with ZrC(001) and VC(001): Photoemission and first-principles studies

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

Rodriguez, J.A.; Liu, P.; Gomes, J.

2005-08-15

High-resolution photoemission and first-principles density-functional calculations were used to study the interaction of oxygen with ZrC(001) and VC(001) surfaces. Atomic oxygen is present on the carbide substrates after small doses of O{sub 2} at room temperature. At 500 K, the oxidation of the surfaces is fast and clear features for ZrO{sub x} or VO{sub x} are seen in the O(1s), Zr(3d), and V(2p{sub 3/2}) core levels spectra, with an increase in the metal/carbon ratio of the samples. A big positive shift (1.3-1.6 eV) was detected for the C 1s core level in O/ZrC(001), indicating the existence of strong O{r_reversible}C ormore » C{r_reversible}C interactions. A phenomenon corroborated by the results of first-principles calculations, which show a CZrZr hollow as the most stable site for the adsorption of O. Furthermore, the calculations also show that a C{r_reversible}O exchange is exothermic on ZrC(001), and the displaced C atoms bond to CZrZr sites. In the O/ZrC(001) interface, the surface C atoms play a major role in determining the behavior of the system. In contrast, the adsorption of oxygen induces very minor changes in the C(1s) spectrum of VC(001). The O{r_reversible}V interactions are stronger than the O{r_reversible}Zr interactions, and O{r_reversible}C interactions do not play a dominant role in the O/VC(001) interface. In this system, C{r_reversible}O exchange is endothermic. VC(001) has a larger density of metal d states near the Fermi level than ZrC(001), but the rate of oxidation of VC(001) is slower. Therefore the O/ZrC(001) and O/VC(001) systems illustrate two different types of pathways for the oxidation of carbide surfaces.« less

NextGen Future Safety Assessment Game

NASA Technical Reports Server (NTRS)

Ancel, Ersin; Gheorghe, Adian; Jones, Sharon Monica

2010-01-01

The successful implementation of the next generation infrastructure systems requires solid understanding of their technical, social, political and economic aspects along with their interactions. The lack of historical data that relate to the long-term planning of complex systems introduces unique challenges for decision makers and involved stakeholders which in turn result in unsustainable systems. Also, the need to understand the infrastructure at the societal level and capture the interaction between multiple stakeholders becomes important. This paper proposes a methodology in order to develop a holistic approach aiming to provide an alternative subject-matter expert (SME) elicitation and data collection method for future sociotechnical systems. The methodology is adapted to Next Generation Air Transportation System (NextGen) decision making environment in order to demonstrate the benefits of this holistic approach.

NextGen Future Safety Assessment Game

NASA Technical Reports Server (NTRS)

Ancel, Ersin; Gheorghe, Adrian; Jones, Sharon Monica

2011-01-01

The successful implementation of the next generation infrastructure systems requires solid understanding of their technical, social, political and economic aspects along with their interactions. The lack of historical data that relate to the long-term planning of complex systems introduces unique challenges for decision makers and involved stakeholders which in turn result in unsustainable systems. Also, the need to understand the infrastructure at the societal level and capture the interaction between multiple stakeholders becomes important. This paper proposes a methodology in order to develop a holistic approach aiming to provide an alternative subject-matter expert (SME) elicitation and data collection method for future sociotechnical systems. The methodology is adapted to Next Generation Air Transportation System (NextGen) decision making environment in order to demonstrate the benefits of this holistic approach.

Age-Related Changes in Binaural Interaction at Brainstem Level.

PubMed

Van Yper, Lindsey N; Vermeire, Katrien; De Vel, Eddy F J; Beynon, Andy J; Dhooge, Ingeborg J M

2016-01-01

Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction. The present study investigates binaural interaction at the level of the auditory brainstem. It is hypothesized that brainstem binaural interaction deteriorates with advancing age. Forty-two subjects of various age participated in the study. Auditory brainstem responses (ABRs) were recorded using clicks and 500 Hz tone-bursts. ABRs were elicited by monaural right, monaural left, and binaural stimulation. Binaural interaction was investigated in two ways. First, grand averages of the binaural interaction component were computed for each age group. Second, wave V characteristics of the binaural ABR were compared with those of the summed left and right ABRs. Binaural interaction in the click ABR was demonstrated by shorter latencies and smaller amplitudes in the binaural compared with the summed monaural responses. For 500 Hz tone-burst ABR, no latency differences were found. However, amplitudes were significantly smaller in the binaural than summed monaural condition. An age-effect was found for 500 Hz tone-burst, but not for click ABR. Brainstem binaural interaction seems to decline with age. Interestingly, these changes seem to be stimulus-dependent.

MUNDUS project: MUltimodal Neuroprosthesis for daily Upper limb Support

PubMed Central

2013-01-01

Background MUNDUS is an assistive framework for recovering direct interaction capability of severely motor impaired people based on arm reaching and hand functions. It aims at achieving personalization, modularity and maximization of the user’s direct involvement in assistive systems. To this, MUNDUS exploits any residual control of the end-user and can be adapted to the level of severity or to the progression of the disease allowing the user to voluntarily interact with the environment. MUNDUS target pathologies are high-level spinal cord injury (SCI) and neurodegenerative and genetic neuromuscular diseases, such as amyotrophic lateral sclerosis, Friedreich ataxia, and multiple sclerosis (MS). The system can be alternatively driven by residual voluntary muscular activation, head/eye motion, and brain signals. MUNDUS modularly combines an antigravity lightweight and non-cumbersome exoskeleton, closed-loop controlled Neuromuscular Electrical Stimulation for arm and hand motion, and potentially a motorized hand orthosis, for grasping interactive objects. Methods The definition of the requirements and of the interaction tasks were designed by a focus group with experts and a questionnaire with 36 potential end-users. Five end-users (3 SCI and 2 MS) tested the system in the configuration suitable to their specific level of impairment. They performed two exemplary tasks: reaching different points in the working volume and drinking. Three experts evaluated over a 3-level score (from 0, unsuccessful, to 2, completely functional) the execution of each assisted sub-action. Results The functionality of all modules has been successfully demonstrated. User’s intention was detected with a 100% success. Averaging all subjects and tasks, the minimum evaluation score obtained was 1.13 ± 0.99 for the release of the handle during the drinking task, whilst all the other sub-actions achieved a mean value above 1.6. All users, but one, subjectively perceived the usefulness of the assistance and could easily control the system. Donning time ranged from 6 to 65 minutes, scaled on the configuration complexity. Conclusions The MUNDUS platform provides functional assistance to daily life activities; the modules integration depends on the user’s need, the functionality of the system have been demonstrated for all the possible configurations, and preliminary assessment of usability and acceptance is promising. PMID:23822118

Comparison of permutationally invariant polynomials, neural networks, and Gaussian approximation potentials in representing water interactions through many-body expansions

NASA Astrophysics Data System (ADS)

Nguyen, Thuong T.; Székely, Eszter; Imbalzano, Giulio; Behler, Jörg; Csányi, Gábor; Ceriotti, Michele; Götz, Andreas W.; Paesani, Francesco

2018-06-01

The accurate representation of multidimensional potential energy surfaces is a necessary requirement for realistic computer simulations of molecular systems. The continued increase in computer power accompanied by advances in correlated electronic structure methods nowadays enables routine calculations of accurate interaction energies for small systems, which can then be used as references for the development of analytical potential energy functions (PEFs) rigorously derived from many-body (MB) expansions. Building on the accuracy of the MB-pol many-body PEF, we investigate here the performance of permutationally invariant polynomials (PIPs), neural networks, and Gaussian approximation potentials (GAPs) in representing water two-body and three-body interaction energies, denoting the resulting potentials PIP-MB-pol, Behler-Parrinello neural network-MB-pol, and GAP-MB-pol, respectively. Our analysis shows that all three analytical representations exhibit similar levels of accuracy in reproducing both two-body and three-body reference data as well as interaction energies of small water clusters obtained from calculations carried out at the coupled cluster level of theory, the current gold standard for chemical accuracy. These results demonstrate the synergy between interatomic potentials formulated in terms of a many-body expansion, such as MB-pol, that are physically sound and transferable, and machine-learning techniques that provide a flexible framework to approximate the short-range interaction energy terms.

Ultrastructural localisation of protein interactions using conditionally stable nanobodies.

PubMed

Ariotti, Nicholas; Rae, James; Giles, Nichole; Martel, Nick; Sierecki, Emma; Gambin, Yann; Hall, Thomas E; Parton, Robert G

2018-04-01

We describe the development and application of a suite of modular tools for high-resolution detection of proteins and intracellular protein complexes by electron microscopy (EM). Conditionally stable GFP- and mCherry-binding nanobodies (termed csGBP and csChBP, respectively) are characterized using a cell-free expression and analysis system and subsequently fused to an ascorbate peroxidase (APEX) enzyme. Expression of these cassettes alongside fluorescently labelled proteins results in recruitment and stabilisation of APEX, whereas unbound APEX nanobodies are efficiently degraded by the proteasome. This greatly simplifies correlative analyses, enables detection of less-abundant proteins, and eliminates the need to balance expression levels between fluorescently labelled and APEX nanobody proteins. Furthermore, we demonstrate the application of this system to bimolecular complementation ('EM split-fluorescent protein'), for localisation of protein-protein interactions at the ultrastructural level.

Ultrastructural localisation of protein interactions using conditionally stable nanobodies

PubMed Central

Ariotti, Nicholas; Rae, James; Giles, Nichole; Martel, Nick; Sierecki, Emma; Gambin, Yann; Parton, Robert G.

2018-01-01

We describe the development and application of a suite of modular tools for high-resolution detection of proteins and intracellular protein complexes by electron microscopy (EM). Conditionally stable GFP- and mCherry-binding nanobodies (termed csGBP and csChBP, respectively) are characterized using a cell-free expression and analysis system and subsequently fused to an ascorbate peroxidase (APEX) enzyme. Expression of these cassettes alongside fluorescently labelled proteins results in recruitment and stabilisation of APEX, whereas unbound APEX nanobodies are efficiently degraded by the proteasome. This greatly simplifies correlative analyses, enables detection of less-abundant proteins, and eliminates the need to balance expression levels between fluorescently labelled and APEX nanobody proteins. Furthermore, we demonstrate the application of this system to bimolecular complementation (‘EM split-fluorescent protein’), for localisation of protein–protein interactions at the ultrastructural level. PMID:29621251

Entanglement dynamics and position-momentum entropic uncertainty relation of a Λ-type three-level atom interacting with a two-mode cavity field in the presence of nonlinearities

NASA Astrophysics Data System (ADS)

Faghihi, M. J.; Tavassoly, M. K.; Hooshmandasl, M. R.

2013-05-01

In this paper, the interaction between a $\\Lambda$-type three-level atom and two-mode cavity field is discussed. The detuning parameters and cross-Kerr nonlinearity are taken into account and it is assumed that atom-field coupling and Kerr medium to be $f$-deformed. Even though the system seems to be complicated, the analytical form of the state vector of the entire system for considered model is exactly obtained. The time evolution of nonclassical properties such as quantum entanglement and position-momentum entropic uncertainty relation (entropy squeezing) of the field are investigated. In each case, the influences of the detuning parameters, generalized Kerr medium and intensity-dependent coupling on the latter nonclassicality signs are analyzed, in detail.

Robustness of self-organised systems to changes in behaviour: an example from real and simulated self-organised snail aggregations.

PubMed

Stafford, Richard; Williams, Gray A; Davies, Mark S

2011-01-01

Group or population level self-organised systems comprise many individuals displaying group-level emergent properties. Current theory indicates that individual-level behaviours have an effect on the final group-level behaviour; that is, self-organised systems are sensitive to small changes in individual behaviour. Here we examine a self-organised behaviour in relation to environmentally-driven individual-level changes in behaviour, using both natural systems and computer simulations. We demonstrate that aggregations of intertidal snails slightly decrease in size when, owing to hotter and more desiccating conditions, individuals forage for shorter periods--a seemingly non-adaptive behaviour for the snails since aggregation reduces desiccation stress. This decrease, however, only occurs in simple experimental systems (and simulations of these systems). When studied in their natural and more complex environment, and simulations of such an environment, using the same reduced foraging time, no difference in aggregation behaviour was found between hot and cool days. These results give an indication of how robust self-organised systems are to changes in individual-level behaviour. The complexity of the natural environment and the interactions of individuals with this environment, therefore, can result in self-organised systems being more resilient to individual-level changes than previously assumed.

Induced dual EIT and EIA resonances with optical trapping phenomenon in near/far fields in the N-type four-level system

NASA Astrophysics Data System (ADS)

Osman, Kariman I.; Joshi, Amitabh

2017-01-01

The optical trapping phenomenon is investigated in the probe absorptive susceptibility spectra, during the interaction of four-level N-type atomic system with three transverse Gaussian fields, in a Doppler broadened medium. The system was studied under different temperature settings of 87Rb atomic vapor as well as different non-radiative decay rate. The system exhibits a combination of dual electromagnetically induced transparency with electromagnetically induced absorption (EIA) or transparency (EIT) resonances simultaneously in near/far field. Also, the optical trapping phenomenon is considerably affected by the non-radiative decay rate.

Visualizing the spinal neuronal dynamics of locomotion

NASA Astrophysics Data System (ADS)

Subramanian, Kalpathi R.; Bashor, D. P.; Miller, M. T.; Foster, J. A.

2004-06-01

Modern imaging and simulation techniques have enhanced system-level understanding of neural function. In this article, we present an application of interactive visualization to understanding neuronal dynamics causing locomotion of a single hip joint, based on pattern generator output of the spinal cord. Our earlier work visualized cell-level responses of multiple neuronal populations. However, the spatial relationships were abstract, making communication with colleagues difficult. We propose two approaches to overcome this: (1) building a 3D anatomical model of the spinal cord with neurons distributed inside, animated by the simulation and (2) adding limb movements predicted by neuronal activity. The new system was tested using a cat walking central pattern generator driving a pair of opposed spinal motoneuron pools. Output of opposing motoneuron pools was combined into a single metric, called "Net Neural Drive", which generated angular limb movement in proportion to its magnitude. Net neural drive constitutes a new description of limb movement control. The combination of spatial and temporal information in the visualizations elegantly conveys the neural activity of the output elements (motoneurons), as well as the resulting movement. The new system encompasses five biological levels of organization from ion channels to observed behavior. The system is easily scalable, and provides an efficient interactive platform for rapid hypothesis testing.

Algebraic aspects of the driven dynamics in the density operator and correlation functions calculation for multi-level open quantum systems

NASA Astrophysics Data System (ADS)

Bogolubov, Nikolai N.; Soldatov, Andrey V.

2017-12-01

Exact and approximate master equations were derived by the projection operator method for the reduced statistical operator of a multi-level quantum system with finite number N of quantum eigenstates interacting with arbitrary external classical fields and dissipative environment simultaneously. It was shown that the structure of these equations can be simplified significantly if the free Hamiltonian driven dynamics of an arbitrary quantum multi-level system under the influence of the external driving fields as well as its Markovian and non-Markovian evolution, stipulated by the interaction with the environment, are described in terms of the SU(N) algebra representation. As a consequence, efficient numerical methods can be developed and employed to analyze these master equations for real problems in various fields of theoretical and applied physics. It was also shown that literally the same master equations hold not only for the reduced density operator but also for arbitrary nonequilibrium multi-time correlation functions as well under the only assumption that the system and the environment are uncorrelated at some initial moment of time. A calculational scheme was proposed to account for these lost correlations in a regular perturbative way, thus providing additional computable terms to the correspondent master equations for the correlation functions.

An affinity-structure database of helix-turn-helix: DNA complexes with a universal coordinate system

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

AlQuraishi, Mohammed; Tang, Shengdong; Xia, Xide

Molecular interactions between proteins and DNA molecules underlie many cellular processes, including transcriptional regulation, chromosome replication, and nucleosome positioning. Computational analyses of protein-DNA interactions rely on experimental data characterizing known protein-DNA interactions structurally and biochemically. While many databases exist that contain either structural or biochemical data, few integrate these two data sources in a unified fashion. Such integration is becoming increasingly critical with the rapid growth of structural and biochemical data, and the emergence of algorithms that rely on the synthesis of multiple data types to derive computational models of molecular interactions. We have developed an integrated affinity-structure database inmore » which the experimental and quantitative DNA binding affinities of helix-turn-helix proteins are mapped onto the crystal structures of the corresponding protein-DNA complexes. This database provides access to: (i) protein-DNA structures, (ii) quantitative summaries of protein-DNA binding affinities using position weight matrices, and (iii) raw experimental data of protein-DNA binding instances. Critically, this database establishes a correspondence between experimental structural data and quantitative binding affinity data at the single basepair level. Furthermore, we present a novel alignment algorithm that structurally aligns the protein-DNA complexes in the database and creates a unified residue-level coordinate system for comparing the physico-chemical environments at the interface between complexes. Using this unified coordinate system, we compute the statistics of atomic interactions at the protein-DNA interface of helix-turn-helix proteins. We provide an interactive website for visualization, querying, and analyzing this database, and a downloadable version to facilitate programmatic analysis. Lastly, this database will facilitate the analysis of protein-DNA interactions and the development of programmatic computational methods that capitalize on integration of structural and biochemical datasets. The database can be accessed at http://ProteinDNA.hms.harvard.edu.« less

An affinity-structure database of helix-turn-helix: DNA complexes with a universal coordinate system

DOE PAGES

AlQuraishi, Mohammed; Tang, Shengdong; Xia, Xide

2015-11-19

Molecular interactions between proteins and DNA molecules underlie many cellular processes, including transcriptional regulation, chromosome replication, and nucleosome positioning. Computational analyses of protein-DNA interactions rely on experimental data characterizing known protein-DNA interactions structurally and biochemically. While many databases exist that contain either structural or biochemical data, few integrate these two data sources in a unified fashion. Such integration is becoming increasingly critical with the rapid growth of structural and biochemical data, and the emergence of algorithms that rely on the synthesis of multiple data types to derive computational models of molecular interactions. We have developed an integrated affinity-structure database inmore » which the experimental and quantitative DNA binding affinities of helix-turn-helix proteins are mapped onto the crystal structures of the corresponding protein-DNA complexes. This database provides access to: (i) protein-DNA structures, (ii) quantitative summaries of protein-DNA binding affinities using position weight matrices, and (iii) raw experimental data of protein-DNA binding instances. Critically, this database establishes a correspondence between experimental structural data and quantitative binding affinity data at the single basepair level. Furthermore, we present a novel alignment algorithm that structurally aligns the protein-DNA complexes in the database and creates a unified residue-level coordinate system for comparing the physico-chemical environments at the interface between complexes. Using this unified coordinate system, we compute the statistics of atomic interactions at the protein-DNA interface of helix-turn-helix proteins. We provide an interactive website for visualization, querying, and analyzing this database, and a downloadable version to facilitate programmatic analysis. Lastly, this database will facilitate the analysis of protein-DNA interactions and the development of programmatic computational methods that capitalize on integration of structural and biochemical datasets. The database can be accessed at http://ProteinDNA.hms.harvard.edu.« less

Progressive reactivation of the volcanic plumbing system beneath Tolbachik volcano (Kamchatka, Russia) revealed by long-period seismicity

NASA Astrophysics Data System (ADS)

Frank, William B.; Shapiro, Nikolaï M.; Gusev, Alexander A.

2018-07-01

After lying dormant for 36 yr, the Tolbachik volcano of the Klyuchevskoy group started to erupt on 27 November 2012. We investigate the preparatory phase of this eruption via a statistical analysis of the temporal behavior of long-period (LP) earthquakes that occurred beneath this volcanic system. The LP seismicity occurs close to the surface beneath the main volcanic edifices and at 30 km depth in the vicinity of a deep magmatic reservoir. The deep LP earthquakes and those beneath the Klyuchevskoy volcano occur quasi-periodically, while the LP earthquakes beneath Tolbachik are clustered in time. As the seismicity rate increased beneath Tolbachik days before the eruption, the level of the time clustering decreased. We interpret this as a manifestation of the evolution of the volcano plumbing system. We suggest that when a plumbing system awakes after quiescence, multiple cracks and channels are reactivated simultaneously and their interaction results in the strong time clustering of LP earthquakes. With time, this network of channels and cracks evolves into a more stable state with an overall increased permeability, where fluids flow uninhibited throughout the plumbing system except for a few remaining impediments that continue to generate seismic radiation. The inter-seismic source interaction and the level of earthquake time clustering in this latter state is weak. This scenario suggests that the observed evolution of the statistical behavior of the shallow LP seismicity beneath Tolbachik is an indicator of the reactivation and consolidation of the near-surface plumbing system prior to the Tolbachik eruption. The parts of the plumbing system above the deep magmatic reservoir and beneath the Klyuchevskoy volcano remain in nearly permanent activity, as demonstrated by the continuous occurrence of the deep LP earthquakes and very frequent Klyuchevskoy eruptions. This implies that these parts of the plumbing system remain in a stable permeable state and contain a few weakly interacting seismogenic sources. Our results provide new constraints on future mechanical models of the magmatic plumbing systems and demonstrate that the level of time clustering of LP earthquakes can be a useful parameter to infer information about the state of the plumbing system.

Urban land use decouples plant-herbivore-parasitoid interactions at multiple spatial scales.

PubMed

Nelson, Amanda E; Forbes, Andrew A

2014-01-01

Intense urban and agricultural development alters habitats, increases fragmentation, and may decouple trophic interactions if plants or animals cannot disperse to needed resources. Specialist insects represent a substantial proportion of global biodiversity and their fidelity to discrete microhabitats provides a powerful framework for investigating organismal responses to human land use. We sampled site occupancy and densities for two plant-herbivore-parasitoid systems from 250 sites across a 360 km2 urban/agricultural landscape to ask whether and how human development decouples interactions between trophic levels. We compared patterns of site occupancy, host plant density, herbivory and parasitism rates of insects at two trophic levels with respect to landcover at multiple spatial scales. Geospatial analyses were used to identify landcover characters predictive of insect distributions. We found that herbivorous insect densities were decoupled from host tree densities in urban landcover types at several spatial scales. This effect was amplified for the third trophic level in one of the two insect systems: despite being abundant regionally, a parasitoid species was absent from all urban/suburban landcover even where its herbivore host was common. Our results indicate that human land use patterns limit distributions of specialist insects. Dispersal constraints associated with urban built development are specifically implicated as a limiting factor.

Urban Land Use Decouples Plant-Herbivore-Parasitoid Interactions at Multiple Spatial Scales

PubMed Central

Nelson, Amanda E.; Forbes, Andrew A.

2014-01-01

Intense urban and agricultural development alters habitats, increases fragmentation, and may decouple trophic interactions if plants or animals cannot disperse to needed resources. Specialist insects represent a substantial proportion of global biodiversity and their fidelity to discrete microhabitats provides a powerful framework for investigating organismal responses to human land use. We sampled site occupancy and densities for two plant-herbivore-parasitoid systems from 250 sites across a 360 km2 urban/agricultural landscape to ask whether and how human development decouples interactions between trophic levels. We compared patterns of site occupancy, host plant density, herbivory and parasitism rates of insects at two trophic levels with respect to landcover at multiple spatial scales. Geospatial analyses were used to identify landcover characters predictive of insect distributions. We found that herbivorous insect densities were decoupled from host tree densities in urban landcover types at several spatial scales. This effect was amplified for the third trophic level in one of the two insect systems: despite being abundant regionally, a parasitoid species was absent from all urban/suburban landcover even where its herbivore host was common. Our results indicate that human land use patterns limit distributions of specialist insects. Dispersal constraints associated with urban built development are specifically implicated as a limiting factor. PMID:25019962

Economic value of ecological information in ecosystem-based natural resource management depends on exploitation history.

PubMed

Essington, Timothy E; Sanchirico, James N; Baskett, Marissa L

2018-02-13

Ecosystem approaches to natural resource management are seen as a way to provide better outcomes for ecosystems and for people, yet the nature and strength of interactions among ecosystem components is usually unknown. Here we characterize the economic benefits of ecological knowledge through a simple model of fisheries that target a predator (piscivore) and its prey. We solve for the management (harvest) trajectory that maximizes net present value (NPV) for different ecological interactions and initial conditions that represent different levels of exploitation history. Optimal management trajectories generally approached similar harvest levels, but the pathways toward those levels varied considerably by ecological scenario. Application of the wrong harvest trajectory, which would happen if one type of ecological interaction were assumed but in fact another were occurring, generally led to only modest reductions in NPV. However, the risks were not equal across fleets: risks of incurring large losses of NPV and missing management targets were much higher in the fishery targeting piscivores, especially when piscivores were heavily depleted. Our findings suggest that the ecosystem approach might provide the greatest benefits when used to identify system states where management performs poorly with imperfect knowledge of system linkages so that management strategies can be adopted to avoid those states. Copyright © 2018 the Author(s). Published by PNAS.

Towards rationally redesigning bacterial signaling systems using information encoded in abundant sequence data

NASA Astrophysics Data System (ADS)

Cheng, Ryan; Morcos, Faruck; Levine, Herbert; Onuchic, Jose

2014-03-01

An important challenge in biology is to distinguish the subset of residues that allow bacterial two-component signaling (TCS) proteins to preferentially interact with their correct TCS partner such that they can bind and transfer signal. Detailed knowledge of this information would allow one to search sequence-space for mutations that can systematically tune the signal transmission between TCS partners as well as re-encode a TCS protein to preferentially transfer signals to a non-partner. Motivated by the notion that this detailed information is found in sequence data, we explore the mutual sequence co-evolution between signaling partners to infer how mutations can positively or negatively alter their interaction. Using Direct Coupling Analysis (DCA) for determining evolutionarily conserved interprotein interactions, we apply a DCA-based metric to quantify mutational changes in the interaction between TCS proteins and demonstrate that it accurately correlates with experimental mutagenesis studies probing the mutational change in the in vitro phosphotransfer. Our methodology serves as a potential framework for the rational design of TCS systems as well as a framework for the system-level study of protein-protein interactions in sequence-rich systems. This research has been supported by the NSF INSPIRE award MCB-1241332 and by the CTBP sponsored by the NSF (Grant PHY-1308264).

Regime shifts and panarchies in regional scale social ...

EPA Pesticide Factsheets

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive governance in heavily regulated and developed social-ecological systems nested within a hierarchical governmental system. We summarize resilience assessments conducted in each system to provide a synthesis and reference by the other articles in this special feature. We also present a general framework used to evaluate the interactions between society and ecosystem regimes and the governance regimes chosen to mediate those interactions. The case studies show different ways that adaptive governance may be triggered, facilitated, or constrained by ecological and/or legal processes. The resilience assessments indicate that complex interactions among the governance and ecosystem components of these systems can produce different trajectories, which include patterns of (a) development and stabilization, (b) cycles of crisis and recovery, which includes lurches in adaptation and learning, and (3) periods of innovation, novelty, and transformation. Exploration of cross scale (Panarchy) interactions among levels and sectors of government and society illustrate that they may constrain development trajectories, but may also provide stability during crisis or innovation at smaller scales; create crises,

Synchronization in human musical rhythms and mutually interacting complex systems

PubMed Central

Hennig, Holger

2014-01-01

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

Peace studies and conflict resolution: the need for transdisciplinarity.

PubMed

Galtung, Johan

2010-02-01

Peace studies seeks to understand the negation of violence through conflict transformation, cooperation and harmony by drawing from many disciplines, including psychology, sociology and anthropology, political science, economics, international relations, international law and history. This raises the problem of the complementarity, coexistence and integration of different systems of knowledge. In fact, all of the human and social sciences are products of the post-Westphalian state system and so reify the state and its internal and international system and focus on this as the main source of political conflict. Conflicts, however, can arise from other distinctions involving gender, generation, race, class and so on. To contribute to peace building and conflict resolution, the social sciences must be globalized, developing theories that address conflicts at the levels of interpersonal interaction (micro), within countries (meso), between nations (macro ), and between whole regions or civilizations (mega). Psychiatry and the "psy" disciplines can contribute to peace building and conflict resolution through understanding the interactions between processes at each of these levels and the mental health or illness of individuals.

Elastic Multi-scale Mechanisms: Computation and Biological Evolution.

PubMed

Diaz Ochoa, Juan G

2018-01-01

Explanations based on low-level interacting elements are valuable and powerful since they contribute to identify the key mechanisms of biological functions. However, many dynamic systems based on low-level interacting elements with unambiguous, finite, and complete information of initial states generate future states that cannot be predicted, implying an increase of complexity and open-ended evolution. Such systems are like Turing machines, that overlap with dynamical systems that cannot halt. We argue that organisms find halting conditions by distorting these mechanisms, creating conditions for a constant creativity that drives evolution. We introduce a modulus of elasticity to measure the changes in these mechanisms in response to changes in the computed environment. We test this concept in a population of predators and predated cells with chemotactic mechanisms and demonstrate how the selection of a given mechanism depends on the entire population. We finally explore this concept in different frameworks and postulate that the identification of predictive mechanisms is only successful with small elasticity modulus.

An Inducible DamID System for Profiling Interactions of Nuclear Lamina Protein Component Lamin B1 with Chromosomes in Mouse Cells.

PubMed

Kozhevnikova, E N; Leshchenko, A E; Pindyurin, A V

2018-05-01

At the level of DNA organization into chromatin, there are mechanisms that define gene expression profiles in specialized cell types. Genes within chromatin regions that are located at the nuclear periphery are generally expressed at lower levels; however, the nature of this phenomenon remains unclear. These parts of chromatin interact with nuclear lamina proteins like Lamin B1 and, therefore, can be identified in a given cell type by chromatin profiling of these proteins. In this study, we created and tested a Dam Identification (DamID) system induced by Cre recombinase using Lamin B1 and mouse embryonic fibroblasts. This inducible system will help to generate genome-wide profiles of chromatin proteins in given cell types and tissues with no need to dissect tissues from organs or separate cells from tissues, which is achieved by using specific regulatory DNA elements and due to the high sensitivity of the method.

Resolution-Adapted All-Atomic and Coarse-Grained Model for Biomolecular Simulations.

PubMed

Shen, Lin; Hu, Hao

2014-06-10

We develop here an adaptive multiresolution method for the simulation of complex heterogeneous systems such as the protein molecules. The target molecular system is described with the atomistic structure while maintaining concurrently a mapping to the coarse-grained models. The theoretical model, or force field, used to describe the interactions between two sites is automatically adjusted in the simulation processes according to the interaction distance/strength. Therefore, all-atomic, coarse-grained, or mixed all-atomic and coarse-grained models would be used together to describe the interactions between a group of atoms and its surroundings. Because the choice of theory is made on the force field level while the sampling is always carried out in the atomic space, the new adaptive method preserves naturally the atomic structure and thermodynamic properties of the entire system throughout the simulation processes. The new method will be very useful in many biomolecular simulations where atomistic details are critically needed.

Intersegmental Eye-Head-Body Interactions during Complex Whole Body Movements

PubMed Central

von Laßberg, Christoph; Beykirch, Karl A.; Mohler, Betty J.; Bülthoff, Heinrich H.

2014-01-01

Using state-of-the-art technology, interactions of eye, head and intersegmental body movements were analyzed for the first time during multiple twisting somersaults of high-level gymnasts. With this aim, we used a unique combination of a 16-channel infrared kinemetric system; a three-dimensional video kinemetric system; wireless electromyography; and a specialized wireless sport-video-oculography system, which was able to capture and calculate precise oculomotor data under conditions of rapid multiaxial acceleration. All data were synchronized and integrated in a multimodal software tool for three-dimensional analysis. During specific phases of the recorded movements, a previously unknown eye-head-body interaction was observed. The phenomenon was marked by a prolonged and complete suppression of gaze-stabilizing eye movements, in favor of a tight coupling with the head, spine and joint movements of the gymnasts. Potential reasons for these observations are discussed with regard to earlier findings and integrated within a functional model. PMID:24763143

Pilot interaction with automated airborne decision making systems

NASA Technical Reports Server (NTRS)

Rouse, W. B.; Hammer, J. M.; Morris, N. M.; Brown, E. N.; Yoon, W. C.

1983-01-01

The use of advanced software engineering methods (e.g., from artificial intelligence) to aid aircraft crews in procedure selection and execution is investigated. Human problem solving in dynamic environments as effected by the human's level of knowledge of system operations is examined. Progress on the development of full scale simulation facilities is also discussed.

Interactions Between Family and Day Care Systems. Final Technical Report.

ERIC Educational Resources Information Center

Romero, Det; And Others

This research report studied the relationship between families and day care centers as systems. Three levels of subjects were investigated: 23 day care centers in Lansing, Michigan, day care staffs and families of children enrolled. Three questionnaires were developed to obtain data on demographic and attitudinal variables. A director's…

Cortisol and Children's Adjustment: The Moderating Role of Sympathetic Nervous System Activity

ERIC Educational Resources Information Center

El-Sheikh, Mona; Erath, Stephen A.; Buckhalt, Joseph A.; Granger, Douglas A.; Mize, Jacquelyn

2008-01-01

We examined relations among cortisol, markers of sympathetic nervous system (SNS) activity (including salivary alpha-amylase and skin conductance level), and children's adjustment. We also tested the Bauer et al. ("Journal of Developmental and Behavioral Pediatrics," 23(2), 102-113, 2002) hypothesis that interactions between the SNS and cortisol…

Cyber Operations Virtual Environment

DTIC Science & Technology

2010-09-01

automated system affects reliance on that system (e.g., Dzindolet, Peterson , Pomranky, Pierce, & Beck, 2003; Lee & Moray, 1994; Lee & See, 2004...described a need for instruction to enable interactive, realistic training ( Hershey , 2008): Network Warfare and Operations Distributed Training...knowledge or needs beyond this shallow level (Beck, Stern, & Haugsjaa, 1996 ). The immediate feedback model employed in behaviorist learning has

Sex Differences in Psychiatric Disease: A Focus on the Glutamate System

PubMed Central

Wickens, Megan M.; Bangasser, Debra A.; Briand, Lisa A.

2018-01-01

Alterations in glutamate, the primary excitatory neurotransmitter in the brain, are implicated in several psychiatric diseases. Many of these psychiatric diseases display epidemiological sex differences, with either males or females exhibiting different symptoms or disease prevalence. However, little work has considered the interaction of disrupted glutamatergic transmission and sex on disease states. This review describes the clinical and preclinical evidence for these sex differences with a focus on two conditions that are more prevalent in women: Alzheimer's disease and major depressive disorder, and three conditions that are more prevalent in men: schizophrenia, autism spectrum disorder, and attention deficit hyperactivity disorder. These studies reveal sex differences at multiple levels in the glutamate system including metabolic markers, receptor levels, genetic interactions, and therapeutic responses to glutamatergic drugs. Our survey of the current literature revealed a considerable need for more evaluations of sex differences in future studies examining the role of the glutamate system in psychiatric disease. Gaining a more thorough understanding of how sex differences in the glutamate system contribute to psychiatric disease could provide novel avenues for the development of sex-specific pharmacotherapies.

Living in the branches: population dynamics and ecological processes in dendritic networks

USGS Publications Warehouse

Grant, E.H.C.; Lowe, W.H.; Fagan, W.F.

2007-01-01

Spatial structure regulates and modifies processes at several levels of ecological organization (e.g. individual/genetic, population and community) and is thus a key component of complex systems, where knowledge at a small scale can be insufficient for understanding system behaviour at a larger scale. Recent syntheses outline potential applications of network theory to ecological systems, but do not address the implications of physical structure for network dynamics. There is a specific need to examine how dendritic habitat structure, such as that found in stream, hedgerow and cave networks, influences ecological processes. Although dendritic networks are one type of ecological network, they are distinguished by two fundamental characteristics: (1) both the branches and the nodes serve as habitat, and (2) the specific spatial arrangement and hierarchical organization of these elements interacts with a species' movement behaviour to alter patterns of population distribution and abundance, and community interactions. Here, we summarize existing theory relating to ecological dynamics in dendritic networks, review empirical studies examining the population- and community-level consequences of these networks, and suggest future research integrating spatial pattern and processes in dendritic systems.

Social interactions among grazing reef fish drive material flux in a coral reef ecosystem.

PubMed

Gil, Michael A; Hein, Andrew M

2017-05-02

In human financial and social systems, exchanges of information among individuals cause speculative bubbles, behavioral cascades, and other correlated actions that profoundly influence system-level function. Exchanges of information are also widespread in ecological systems, but their effects on ecosystem-level processes are largely unknown. Herbivory is a critical ecological process in coral reefs, where diverse assemblages of fish maintain reef health by controlling the abundance of algae. Here, we show that social interactions have a major effect on fish grazing rates in a reef ecosystem. We combined a system for observing and manipulating large foraging areas in a coral reef with a class of dynamical decision-making models to reveal that reef fish use information about the density and actions of nearby fish to decide when to feed on algae and when to flee foraging areas. This "behavioral coupling" causes bursts of feeding activity that account for up to 68% of the fish community's consumption of algae. Moreover, correlations in fish behavior induce a feedback, whereby each fish spends less time feeding when fewer fish are present, suggesting that reducing fish stocks may not only reduce total algal consumption but could decrease the amount of algae each remaining fish consumes. Our results demonstrate that social interactions among consumers can have a dominant effect on the flux of energy and materials through ecosystems, and our methodology paves the way for rigorous in situ measurements of the behavioral rules that underlie ecological rates in other natural systems.

Design Environment for Multifidelity and Multidisciplinary Components

NASA Technical Reports Server (NTRS)

Platt, Michael

2014-01-01

One of the greatest challenges when developing propulsion systems is predicting the interacting effects between the fluid loads, thermal loads, and structural deflection. The interactions between technical disciplines often are not fully analyzed, and the analysis in one discipline often uses a simplified representation of other disciplines as an input or boundary condition. For example, the fluid forces in an engine generate static and dynamic rotor deflection, but the forces themselves are dependent on the rotor position and its orbit. It is important to consider the interaction between the physical phenomena where the outcome of each analysis is heavily dependent on the inputs (e.g., changes in flow due to deflection, changes in deflection due to fluid forces). A rigid design process also lacks the flexibility to employ multiple levels of fidelity in the analysis of each of the components. This project developed and validated an innovative design environment that has the flexibility to simultaneously analyze multiple disciplines and multiple components with multiple levels of model fidelity. Using NASA's open-source multidisciplinary design analysis and optimization (OpenMDAO) framework, this multifaceted system will provide substantially superior capabilities to current design tools.

Space station WP-04 power system preliminary analysis and design document, volume 3

NASA Technical Reports Server (NTRS)

1986-01-01

Rocketdyne plans to generate a system level specification for the Space Station Electric Power System (EPS) in order to facilitate the usage, accountability, and tracking of overall system level requirements. The origins and status of the verification planning effort are traced and an overview of the Space Station program interactions are provided. The work package level interfaces between the EPS and the other Space Station work packages are outlined. A trade study was performed to determine the peaking split between PV and SD, and specifically to compare the inherent total peaking capability with proportionally shared peaking. In order to determine EPS cost drivers for the previous submittal of DRO2, the life cycle cost (LCC) model was run to identify the more significant costs and the factors contributing to them.

Transferring data objects: A focused Ada investigation

NASA Technical Reports Server (NTRS)

Legrand, Sue

1988-01-01

The use of the Ada language does not guarantee that data objects will be in the same form or have the same value after they have been stored or transferred to another system. There are too many possible variables in such things as the formats used and other protocol conditions. Differences may occur at many different levels of support. These include program level, object level, application level, and system level. A standard language is only one aspect of making a complex system completely homogeneous. Many components must be standardized and the various standards must be integrated. The principal issues in providing for interaction between systems are of exchanging files and data objects between systems which may not be compatible in terms of their host computer, operating system or other factors. A typical resolution of the problem of invalidating data involves at least a common external form, for data objects and for representing the relationships and attributes of data collections. Some of the issues dealing with the transfer of data are listed and consideration is given on how these issues may be handled in the Ada language.

GODIVA2: interactive visualization of environmental data on the Web.

PubMed

Blower, J D; Haines, K; Santokhee, A; Liu, C L

2009-03-13

GODIVA2 is a dynamic website that provides visual access to several terabytes of physically distributed, four-dimensional environmental data. It allows users to explore large datasets interactively without the need to install new software or download and understand complex data. Through the use of open international standards, GODIVA2 maintains a high level of interoperability with third-party systems, allowing diverse datasets to be mutually compared. Scientists can use the system to search for features in large datasets and to diagnose the output from numerical simulations and data processing algorithms. Data providers around Europe have adopted GODIVA2 as an INSPIRE-compliant dynamic quick-view system for providing visual access to their data.

The MiSPOT System: Personalized Publicity and Marketing over Interactive Digital TV

NASA Astrophysics Data System (ADS)

López-Nores, Martín; Pazos-Arias, José Juan; Blanco-Fernández, Yolanda; García-Duque, Jorge; Tubío-Pardavila, Ricardo; Rey-López, Marta

The development of Interactive Digital TV bears a great potential for electronic commerce, which remains heavily underexploited to date. The early initiatives to harness these technologies rely on the advertising techniques traditionally employed by the television industry, which have proven deficiencies related to viewers' comfort, locality and targeting. Furthermore, out of dedicated channels, there are very few attempts to provide interactive commercial functionalities through the TV, for example to sell products or to hire services. This chapter presents an overview of a system called MiSPOT that introduces solutions to these problems in two levels: (i) to advertise items that match the preferences and needs of the viewers, without interfering with their enjoyment of the TV programs; and (ii) to assemble specialized interactive applications that provide them with tailor-made commercial functionalities. These solutions are grounded on techniques from the Semantic Web, and are valid for both domestic TV receivers and mobile ones.

Initial-state-independent equilibration at the breakdown of the eigenstate thermalization hypothesis

NASA Astrophysics Data System (ADS)

Khodja, Abdellah; Schmidtke, Daniel; Gemmer, Jochen

2016-04-01

This work aims at understanding the interplay between the eigenstate thermalization hypothesis (ETH), initial state independent equilibration, and quantum chaos in systems that do not have a direct classical counterpart. It is based on numerical investigations of asymmetric Heisenberg spin ladders with varied interaction strengths between the legs, i.e., along the rungs. The relaxation of the energy difference between the legs is investigated. Two different parameters, both intended to quantify the degree of accordance with the ETH, are computed. Both indicate violation of the ETH at large interaction strengths but at different thresholds. Indeed, the energy difference is found not to relax independently of its initial value above some critical interaction strength, which coincides with one of the thresholds. At the same point the level statistics shift from Poisson-type to Wigner-type. Hence, the system may be considered to become integrable again in the strong interaction limit.

Designing learning environments to teach interactive Quantum Physics

NASA Astrophysics Data System (ADS)

Gómez Puente, Sonia M.; Swagten, Henk J. M.

2012-10-01

This study aims at describing and analysing systematically an interactive learning environment designed to teach Quantum Physics, a second-year physics course. The instructional design of Quantum Physics is a combination of interactive lectures (using audience response systems), tutorials and self-study in unit blocks, carried out with small groups. Individual formative feedback was introduced as a rapid assessment tool to provide an overview on progress and identify gaps by means of questioning students at three levels: conceptual; prior knowledge; homework exercises. The setup of Quantum Physics has been developed as a result of several loops of adjustments and improvements from a traditional-like type of teaching to an interactive classroom. Results of this particular instructional arrangement indicate significant gains in students' achievements in comparison with the traditional structure of this course, after recent optimisation steps such as the implementation of an individual feedback system.

Psychological Stability of a Personality and Capability of Tolerant Interaction as Diverse Manifestations of Tolerance

ERIC Educational Resources Information Center

Belasheva, Irina Valeryevna; Petrova, Nina Fedorovna

2016-01-01

Present article addresses studying tolerance as a factor of personality stability, which manifests on the level of interpersonal relationships and on the level of intra-personal system of stressors resistance. The article includes theoretical analysis of the tolerance construct as an integrative personality formation. It explores the question of…

Using Graph-Based Assessments within Socratic Tutorials to Reveal and Refine Students' Analytical Thinking about Molecular Networks

ERIC Educational Resources Information Center

Trujillo, Caleb; Cooper, Melanie M.; Klymkowsky, Michael W.

2012-01-01

Biological systems, from the molecular to the ecological, involve dynamic interaction networks. To examine student thinking about networks we used graphical responses, since they are easier to evaluate for implied, but unarticulated assumptions. Senior college level molecular biology students were presented with simple molecular level scenarios;…

A Systematic Review of Agent-Based Modelling and Simulation Applications in the Higher Education Domain

ERIC Educational Resources Information Center

Gu, X.; Blackmore, K. L.

2015-01-01

This paper presents the results of a systematic review of agent-based modelling and simulation (ABMS) applications in the higher education (HE) domain. Agent-based modelling is a "bottom-up" modelling paradigm in which system-level behaviour (macro) is modelled through the behaviour of individual local-level agent interactions (micro).…

Quality Assurance Processes in Finnish Universities: Direct and Indirect Outcomes and Organisational Conditions

ERIC Educational Resources Information Center

Haapakorpi, Arja

2011-01-01

In Finland, quality assurance related to the Bologna process has been adapted to existing systems of higher education at the national level and a form of implementation is also recognised at the level of the higher education institution. In universities, varied outcomes of quality assurance are based on interaction of organisational structures,…

From Here to Autonomy.

PubMed

Endsley, Mica R

2017-02-01

As autonomous and semiautonomous systems are developed for automotive, aviation, cyber, robotics and other applications, the ability of human operators to effectively oversee and interact with them when needed poses a significant challenge. An automation conundrum exists in which as more autonomy is added to a system, and its reliability and robustness increase, the lower the situation awareness of human operators and the less likely that they will be able to take over manual control when needed. The human-autonomy systems oversight model integrates several decades of relevant autonomy research on operator situation awareness, out-of-the-loop performance problems, monitoring, and trust, which are all major challenges underlying the automation conundrum. Key design interventions for improving human performance in interacting with autonomous systems are integrated in the model, including human-automation interface features and central automation interaction paradigms comprising levels of automation, adaptive automation, and granularity of control approaches. Recommendations for the design of human-autonomy interfaces are presented and directions for future research discussed.

Siblings of Children with Autism: the Siblings Embedded Systems Framework.

PubMed

Kovshoff, Hanna; Cebula, Katie; Tsai, Hsiao-Wei Joy; Hastings, Richard P

2017-01-01

A range of interacting factors/mechanisms at the individual, family, and wider systems levels influences siblings living in families where one sibling has autism. We introduce the Sibling Embedded Systems Framework which aims to contextualise siblings' experience and characterise the multiple and interacting factors influencing family and, in particular, sibling outcomes. Findings from studies that have reported outcomes for siblings of children with autism are equivocal, ranging from negative impact, no difference, to positive experience. This is likely due to the complex nature of understanding the sibling experience. We focus on particular elements of the framework and review recent novel literature to help guide future directions for research and practice including the influence of culture, methodological considerations, and wider participatory methods. The Siblings Embedded System Framework can be used to understand interactive factors that affect sibling adjustment and to develop clinically, educationally and empirically based work that aims to enhance and support sibling adjustment, relationships, and well-being in families of children with autism.

System identification of the Arabidopsis plant circadian system

NASA Astrophysics Data System (ADS)

Foo, Mathias; Somers, David E.; Kim, Pan-Jun

2015-02-01

The circadian system generates an endogenous oscillatory rhythm that governs the daily activities of organisms in nature. It offers adaptive advantages to organisms through a coordination of their biological functions with the optimal time of day. In this paper, a model of the circadian system in the plant Arabidopsis (species thaliana) is built by using system identification techniques. Prior knowledge about the physical interactions of the genes and the proteins in the plant circadian system is incorporated in the model building exercise. The model is built by using primarily experimentally-verified direct interactions between the genes and the proteins with the available data on mRNA and protein abundances from the circadian system. Our analysis reveals a great performance of the model in predicting the dynamics of the plant circadian system through the effect of diverse internal and external perturbations (gene knockouts and day-length changes). Furthermore, we found that the circadian oscillatory rhythm is robust and does not vary much with the biochemical parameters except those of a light-sensitive protein P and a transcription factor TOC1. In other words, the circadian rhythmic profile is largely a consequence of the network's architecture rather than its particular parameters. Our work suggests that the current experimental knowledge of the gene-to-protein interactions in the plant Arabidopsis, without considering any additional hypothetical interactions, seems to suffice for system-level modeling of the circadian system of this plant and to present an exemplary platform for the control of network dynamics in complex living organisms.

Magnitude and nature of carbohydrate-aromatic interactions in fucose-phenol and fucose-indole complexes: CCSD(T) level interaction energy calculations.

PubMed

Tsuzuki, Seiji; Uchimaru, Tadafumi; Mikami, Masuhiro

2011-10-20

The CH/π contact structures of the fucose-phenol and fucose-indole complexes and the stabilization energies by formation of the complexes (E(form)) were studied by ab initio molecular orbital calculations. The three types of interactions (CH/π and OH/π interactions and OH/O hydrogen bonds) were compared and evaluated in a single molecular system and at the same level of theory. The E(form) calculated for the most stable CH/π contact structure of the fucose-phenol complex at the CCSD(T) level (-4.9 kcal/mol) is close to that for the most stable CH/π contact structure of the fucose-benzene complex (-4.5 kcal/mol). On the other hand the most stable CH/π contact structure of the fucose-indole complex has substantially larger E(form) (-6.5 kcal/mol). The dispersion interaction is the major source of the attraction in the CH/π contact structures of the fucose-phenol and fucose-indole complexes as in the case of the fucose-benzene complex. The electrostatic interactions in the CH/π contact structures are small (less than 1.5 kcal/mol). The nature of the interactions between the nonpolar surface of the carbohydrate and aromatic rings is completely different from that of the conventional hydrogen bonds where the electrostatic interaction is the major source of the attraction. The distributed multipole analysis and DFT-SATP analysis show that the dispersion interactions in the CH/π contact structure of fucose-indole complex are substantially larger than those in the CH/π contact structures of fucose-benzene and fucose-phenol complexes. The large dispersion interactions are responsible for the large E(form) for the fucose-indole complex.

Intervalley scattering induced by Coulomb interaction and disorder in carbon-nanotube quantum dots

NASA Astrophysics Data System (ADS)

Secchi, Andrea; Rontani, Massimo

2013-09-01

We develop a theory of intervalley Coulomb scattering in semiconducting carbon-nanotube quantum dots, taking into account the effects of curvature and chirality. Starting from the effective mass description of single-particle states, we study the two-electron system by fully including Coulomb interaction, spin-orbit coupling, and short-range disorder. We find that the energy level splittings associated with intervalley scattering are nearly independent of the chiral angle and, while smaller than those due to spin-orbit interaction, large enough to be measurable.

JEDI - an executive dashboard and decision support system for lean global military medical resource and logistics management.

PubMed

Sloane, Elliot B; Rosow, Eric; Adam, Joe; Shine, Dave

2006-01-01

Each individual U.S. Air Force, Army, and Navy Surgeon General has integrated oversight of global medical supplies and resources using the Joint Medical Asset Repository (JMAR). A Business Intelligence system called the JMAR Executive Dashboard Initiative (JEDI) was developed over a three-year period to add real-time interactive data-mining tools and executive dashboards. Medical resources can now be efficiently reallocated to military, veteran, family, or civilian purposes and inventories can be maintained at lean levels with peaks managed by interactive dashboards that reduce workload and errors.

Suppressor cell hyperactivity relative to allogeneic lymphocyte proliferation as a manifestation of defective T-T-cell interactions in systemic lupus erythematosus

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

Stenina, M.A.; Potapova, A.A.; Biryukov, A.V.

1987-01-01

The authors study the state of immunoregulatory process in patients with systemic lupus erythematosus at the T-T-cell interaction level and seek to test the possibility of the pharmacological modulation of this process. The proliferative activity of mononuclear lymphocytes, extracted from the blood of ten lupus patients, was assessed by measuring the incorporation of tritiated thymidine into cultures stimulated by phytohemagglutinin, concanavalin, and theophylline. The comparative effects of each of these agents on the immunoregulatory and proliferative activity of the lymphocytes are reported.