Orbital State Manipulation of a Diamond Nitrogen-Vacancy Center Using a Mechanical Resonator

NASA Astrophysics Data System (ADS)

Chen, H. Y.; MacQuarrie, E. R.; Fuchs, G. D.

2018-04-01

We study the resonant optical transitions of a single nitrogen-vacancy (NV) center that is coherently dressed by a strong mechanical drive. Using a gigahertz-frequency diamond mechanical resonator that is strain coupled to a NV center's orbital states, we demonstrate coherent Raman sidebands out to the ninth order and orbital-phonon interactions that mix the two excited-state orbital branches. These interactions are spectroscopically revealed through a multiphonon Rabi splitting of the orbital branches which scales as a function of resonator driving amplitude and is successfully reproduced in a quantum model. Finally, we discuss the application of mechanical driving to engineering NV-center orbital states.

Regulatory interactions in the dimeric cytochrome bc(1) complex: the advantages of being a twin.

PubMed

Covian, Raul; Trumpower, Bernard L

2008-09-01

The dimeric cytochrome bc(1) complex catalyzes the oxidation-reduction of quinol and quinone at sites located in opposite sides of the membrane in which it resides. We review the kinetics of electron transfer and inhibitor binding that reveal functional interactions between the quinol oxidation site at center P and quinone reduction site at center N in opposite monomers in conjunction with electron equilibration between the cytochrome b subunits of the dimer. A model for the mechanism of the bc(1) complex has emerged from these studies in which binding of ligands that mimic semiquinone at center N regulates half-of-the-sites reactivity at center P and binding of ligands that mimic catalytically competent binding of ubiquinol at center P regulates half-of-the-sites reactivity at center N. An additional feature of this model is that inhibition of quinol oxidation at the quinone reduction site is avoided by allowing catalysis in only one monomer at a time, which maximizes the number of redox acceptor centers available in cytochrome b for electrons coming from quinol oxidation reactions at center P and minimizes the leakage of electrons that would result in the generation of damaging oxygen radicals.

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

EPA Science Inventory

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

Low Speed Rot or/Fuselage Interactional Aerodynamics

NASA Technical Reports Server (NTRS)

Barnwell, Richard W.; Prichard, Devon S.

2003-01-01

This report presents work performed under a Cooperative Research Agreement between Virginia Tech and the NASA Langley Research Center. The work involved development of computational techniques for modeling helicopter rotor/airframe aerodynamic interaction. A brief overview of the problem is presented, the modeling techniques are described, and selected example calculations are briefly discussed.

Physical Foundations for Socio-Economic Modeling for Transportation Planning : Part 1. Interaction Between Urban Centers as a Potential Process.

DOT National Transportation Integrated Search

1977-09-01

The objective of this research is to make use of a physically based social system model to study the determinants of city sizes and their interactions in a nation. In particular, it was required that attention be paid to how new transportation system...

Early prediction of student goals and affect in narrative-centered learning environments

NASA Astrophysics Data System (ADS)

Lee, Sunyoung

Recent years have seen a growing recognition of the role of goal and affect recognition in intelligent tutoring systems. Goal recognition is the task of inferring users' goals from a sequence of observations of their actions. Because of the uncertainty inherent in every facet of human computer interaction, goal recognition is challenging, particularly in contexts in which users can perform many actions in any order, as is the case with intelligent tutoring systems. Affect recognition is the task of identifying the emotional state of a user from a variety of physical cues, which are produced in response to affective changes in the individual. Accurately recognizing student goals and affect states could contribute to more effective and motivating interactions in intelligent tutoring systems. By exploiting knowledge of student goals and affect states, intelligent tutoring systems can dynamically modify their behavior to better support individual students. To create effective interactions in intelligent tutoring systems, goal and affect recognition models should satisfy two key requirements. First, because incorrectly predicted goals and affect states could significantly diminish the effectiveness of interactive systems, goal and affect recognition models should provide accurate predictions of user goals and affect states. When observations of users' activities become available, recognizers should make accurate early" predictions. Second, goal and affect recognition models should be highly efficient so they can operate in real time. To address key issues, we present an inductive approach to recognizing student goals and affect states in intelligent tutoring systems by learning goals and affect recognition models. Our work focuses on goal and affect recognition in an important new class of intelligent tutoring systems, narrative-centered learning environments. We report the results of empirical studies of induced recognition models from observations of students' interactions in narrative-centered learning environments. Experimental results suggest that induced models can make accurate early predictions of student goals and affect states, and they are sufficiently efficient to meet the real-time performance requirements of interactive learning environments.

Importance of Nuclear Physics to NASA's Space Missions

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

2001-01-01

We show that nuclear physics is extremely important for accurate risk assessments for space missions. Due to paucity of experimental input radiation interaction information it is imperative to develop reliable accurate models for the interaction of radiation with matter. State-of-the-art nuclear cross sections models have been developed at the NASA Langley Research center and are discussed.

Calculated wind noise for an infrasonic wind noise enclosure.

PubMed

Abbott, JohnPaul; Raspet, Richard

2015-07-01

A simple calculation of the wind noise measured at the center of a large porous wind fence enclosure is developed. The calculation provides a good model of the measured wind noise, with a good agreement within ±5 dB, and is derived by combining the wind noise contributions from (a) the turbulence-turbulence and turbulence-shear interactions inside the enclosure, (b) the turbulence interactions on the surface of the enclosure, and (c) the turbulence-shear interactions outside of the enclosure. Each wind noise contribution is calculated from the appropriate measured turbulence spectra, velocity profiles, correlation lengths, and the mean velocity at the center, surface, and outside of the enclosure. The model is verified by comparisons of the measured wind noise to the calculated estimates of the differing noise contributions and their sum.

Further Investigations of Gravity Modeling on Surface-Interacting Vehicle Simulations

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2009-01-01

A vehicle simulation is "surface-interacting" if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. The dynamics of surface-interacting simulations are influenced by the modeling of gravity. Gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. Both components are functions of position relative to the world s center and that position for a given set of geodetic coordinates (latitude, longitude, and altitude) depends on the world model (world shape and dynamics). Thus, gravity fidelity depends on the fidelities of the gravitation model and the world model and on the interaction of the gravitation and world model. A surface-interacting simulation cannot treat the gravitation separately from the world model. This paper examines the actual performance of different pairs of world and gravitation models (or direct gravity models) on the travel of a subsonic civil transport in level flight under various starting conditions.

Gravity Modeling Effects on Surface-Interacting Vehicles in Supersonic Flight

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2010-01-01

A vehicle simulation is "surface-interacting" if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations per-form ascent, entry, descent, landing, surface travel, or atmospheric flight. The dynamics of surface-interacting simulations are influenced by the modeling of gravity. Gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. Both components are functions of position relative to the world s center and that position for a given set of geodetic coordinates (latitude, longitude, and altitude) depends on the world model (world shape and dynamics). Thus, gravity fidelity depends on the fidelities of the gravitation model and the world model and on the interaction of these two models. A surface-interacting simulation cannot treat gravitation separately from the world model. This paper examines the actual performance of different pairs of world and gravitation models (or direct gravity models) on the travel of a supersonic aircraft in level flight under various start-ing conditions.

Thermodynamic models to elucidate the enantioseparation of drugs with two stereogenic centers by micellar electrokinetic chromatography.

PubMed

Guo, Xuming; Liu, Qiuxia; Hu, Shaoqiang; Guo, Wenbo; Yang, Zhuo; Zhang, Yonghua

2017-08-25

An equilibrium model depicting the simultaneous protonation of chiral drugs and partitioning of protonated ions and neutral molecules into chiral micelles in micellar electrokinetic chromatography (MEKC) has been introduced. It was used for the prediction and elucidation of complex changes in migration order patterns with experimental conditions in the enantioseparation of drugs with two stereogenic centers. Palonosetron hydrochloride (PALO), a weakly basic drug with two stereogenic centers, was selected as a model drug. Its four stereoisomers were separated by MEKC using sodium cholate (SC) as chiral selector and surfactant. Based on the equilibrium model, equations were derived for a calculation of the effective mobility and migration time of each stereoisomer at a certain pH. The migration times of four stereoisomers at different pHs were calculated and then the migration order patterns were constructed with derived equations. The results were in accord with the experiment. And the contribution of each mechanism to the separation and its influence on the migration order pattern was analyzed separately by introducing virtual isomers, i.e., hypothetical stereoisomers with only one parameter changed relative to a real PALO stereoisomer. A thermodynamic model for a judgment of the correlation of interactions between two stereogenic centers of stereoisomers and chiral selector was also proposed. According to this model, the interactions of two stereogenic centers of PALO stereoisomers in both neutral molecules and protonated ions with chiral selector are not independent, so the chiral recognition in each pair of enantiomers as well as the recognition for diastereomers is not simply the algebraic sum of the contributions of two stereogenic centers due to their correlation. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of Interactive Computer Programs To Help Students Transfer Basic Skills to College Level Science and Behavioral Science Courses.

ERIC Educational Resources Information Center

Mikulecky, Larry

Interactive computer programs, developed at Indiana University's Learning Skills Center, were designed to model effective strategies for reading biology and psychology textbooks. For each subject area, computer programs and textbook passages were used to instruct and model for students how to identify key concepts, compare and contrast concepts,…

Combining Multiple Forms Of Visual Information To Specify Contact Relations In Spatial Layout

NASA Astrophysics Data System (ADS)

Sedgwick, Hal A.

1990-03-01

An expert system, called Layout2, has been described, which models a subset of available visual information for spatial layout. The system is used to examine detailed interactions between multiple, partially redundant forms of information in an environment-centered geometrical model of an environment obeying certain rather general constraints. This paper discusses the extension of Layout2 to include generalized contact relations between surfaces. In an environment-centered model, the representation of viewer-centered distance is replaced by the representation of environmental location. This location information is propagated through the representation of the environment by a network of contact relations between contiguous surfaces. Perspective information interacts with other forms of information to specify these contact relations. The experimental study of human perception of contact relations in extended spatial layouts is also discussed. Differences between human results and Layout2 results reveal limitations in the human ability to register available information; they also point to the existence of certain forms of information not yet formalized in Layout2.

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

The evolving concept of "patient-centeredness" in patient-physician communication research.

PubMed

Ishikawa, Hirono; Hashimoto, Hideki; Kiuchi, Takahiro

2013-11-01

Over the past few decades, the concept of "patient-centeredness" has been intensively studied in health communication research on patient-physician interaction. Despite its popularity, this concept has often been criticized for lacking a unified definition and operationalized measurement. This article reviews how health communication research on patient-physician interaction has conceptualized and operationalized patient-centered communication based on four major theoretical perspectives in sociology (i.e., functionalism, conflict theory, utilitarianism, and social constructionism), and discusses the agenda for future research in this field. Each theory addresses different aspects of the patient-physician relationship and communication from different theoretical viewpoints. Patient-centeredness is a multifaceted construct with no single theory that can sufficiently define the whole concept. Different theoretical perspectives of patient-centered communication can be selectively adopted according to the context and nature of problems in the patient-physician relationship that a particular study aims to explore. The present study may provide a useful framework: it offers an overview of the differing models of patient-centered communication and the expected roles and goals in each model; it does so toward identifying a communication model that fits the patient and the context and toward theoretically reconstructing existing measures of patient-centered communication. Furthermore, although patient-centered communication has been defined mainly from the viewpoint of physician's behaviors aimed at achieving patient-centered care, patient competence is also required for patient-centered communication. This needs to be examined in current medical practice. Copyright © 2013 Elsevier Ltd. All rights reserved.

New Dimensions in Patient–Physician Interaction: Values, Autonomy, and Medical Information in the Patient-Centered Clinical Encounter

PubMed Central

Agarwal, Aakash Kumar; Murinson, Beth Brianna

2012-01-01

Patient–physician interactions are increasingly influenced by the extraordinary diversification of populations and rapid expansion of medical knowledge that characterize our modern era. By contrast, the patient–physician interaction models currently used to teach medical trainees have little capacity to address these twin challenges. We developed a new model of patient–physician interaction to explicitly address these problems. Historically, models of patient–physician interaction viewed patient autonomy and the manifestation of clearly defined health care-related values as tightly linked, and it was assumed that patients’ medical knowledge was low. Unfortunately, this does not adequately represent patients such as 1) the highly educated non-medical specialist who possesses little familiarity with health-related values but is highly autonomous, and 2) the patient from a non-Western background who may have well-established health care-related values but a low sense of personal independence. In addition, it is evident to us that the assumption that all patients possess little medical knowledge can create alienation between patient and physician, e.g. the well-informed patient with a rare disease. We propose a paradigm that models autonomy, health care-related values formation, and medical knowledge as varying from patient to patient. Four examples of patient types are described within the context of the model based on clinical experience. We believe that adopting this model will have implications for optimizing patient–physician interactions and teaching about patient-centered care. Further research is needed to identify relevant patient types within this framework and to assess the impact on health care outcomes. PMID:23908841

Insights into linearized rotor dynamics, Part 2

NASA Astrophysics Data System (ADS)

Adams, M. L.

1987-01-01

This paper builds upon its 1981 namesake to extend and propose ideas which focus on some unique problems at the current center of interest in rotor vibration technology. These problems pertain to the ongoing extension of the linearized rotor-bearing model to include other rotor-stator interactive forces such as seals and turbomachinery stages. A unified linear model is proposed and contains an axiom which requires the coefficient matrix of the highest order term, in an interactive force model, to be symmetric. The paper ends on a fundamental question, namely, the potential weakness inherent in the whole idea of mechanical impedance modeling of rotor-stator interactive fluid flow fields.

Cancer Care Initiative: Creation of a Comprehensive Cancer Center at Naval Medical Center Dan Diego

DTIC Science & Technology

2008-06-24

to know about and practice evidence - based medicine and are more experienced with many of the complexities related to difficult chronic illnesses...frequent requesters of evidence - based medicine . Clinical information systems are important to the model to help ensure productive interactions. An

UVM Transportation Research Center signature project 1B : integrated land-use, transportation and environmental modeling.

DOT National Transportation Integrated Search

2014-05-01

Land use and transportation are inextricably linked. Models that capture the dynamics and interactions : of both systems are indispensable for evaluating alternative courses of action in policy and investment. : These models must be spatially disaggr...

Aerodynamic Interaction Effects of a Helicopter Rotor and Fuselage

NASA Technical Reports Server (NTRS)

Boyd, David D., Jr.

1999-01-01

A three year Cooperative Research Agreements made in each of the three years between the Subsonic Aerodynamics Branch of the NASA Langley Research Center and the Virginia Polytechnic Institute and State University (Va. Tech) has been completed. This document presents results from this three year endeavor. The goal of creating an efficient method to compute unsteady interactional effects between a helicopter rotor and fuselage has been accomplished. This paper also includes appendices to support these findings. The topics are: 1) Rotor-Fuselage Interactions Aerodynamics: An Unsteady Rotor Model; and 2) Rotor/Fuselage Unsteady Interactional Aerodynamics: A New Computational Model.

Spatial patterns of arrests, police assault and addiction treatment center locations in Tijuana, Mexico.

PubMed

Werb, Dan; Strathdee, Steffanie A; Vera, Alicia; Arredondo, Jaime; Beletsky, Leo; Gonzalez-Zuniga, Patricia; Gaines, Tommi

2016-07-01

In the context of a public health-oriented drug policy reform in Mexico, we assessed the spatial distribution of police encounters among people who inject drugs (PWID) in Tijuana, determined the association between these encounters and the location of addiction treatment centers and explored the association between police encounters and treatment access. Geographically weighted regression (GWR) and logistic regression analysis using prospective spatial data from a community-recruited cohort of PWID in Tijuana and official geographical arrest data from the Tijuana Municipal Police Department. Tijuana, Mexico. A total of 608 participants (median age 37; 28.4% female) in the prospective Proyecto El Cuete cohort study recruited between January and December 2011. We compared the mean distance of police encounters and a randomly distributed set of events to treatment centers. GWR was undertaken to model the spatial relationship between police interactions and treatment centers. Logistic regression analysis was used to investigate factors associated with reporting police interactions. During the study period, 27.5% of police encounters occurred within 500 m of treatment centers. The GWR model suggested spatial correlation between encounters and treatment centers (global R(2)  = 0.53). Reporting a need for addiction treatment was associated with reporting arrest and police assault [adjusted odds ratio = 2.74, 95% confidence interval (CI) = 1.25-6.02, P = 0.012]. A geospatial analysis suggests that, in Mexico, people who inject drugs are at greater risk of being a victim of police violence if they consider themselves in need of addiction treatment, and their interactions with police appear to be more frequent around treatment centers. © 2016 Society for the Study of Addiction.

Phase 1 report : UVM transportation research center signature project 1B : integrated land use, transportation and environmental modeling.

DOT National Transportation Integrated Search

2010-07-01

Land use and transportation are inextricably linked. Models that capture the dynamics and interactions of both systems are indispensable for evaluating alternative courses of action in policy and investment. These models must be spatially disaggregat...

Moving from reclusion to partial freedom: the experience of family caregivers for disabled elderly persons assisted in a day care center.

PubMed

Bocchi, Silvia Cristina Mangini; Cano, Karen Cristina Urtado; Baltieri, Lilian; Godoy, Daniele Cristina; Spiri, Wilza Carla; Juliani, Carmen Maria Casquel Monti

2010-09-01

This study aimed at understanding the interactional experience between family caregivers and disabled elderly persons supported in a Day Care Center according to the caregiver's perspective. It also aimed at developing a representative theoretical model for the events experienced by such caregiver. The Grounded Theory was used as methodological framework whereas Interactional Symbolism served as the theoretical framework. Observation and interviews were used for data collection. The following phenomenon arose from the results: feeling of support by the Day Care Center, by the strength of the bond with the elderly and by spirituality in order to continue playing the challenging role of a family caregiver for a disabled elderly person. The study made possible to understand that, among these three supporting cornerstones for coping with the burden generated by the family caregiver role, the care model promoted by the Day Care Center was the intervenient variable in the process of improving the quality of life of the family caregiver-disabled elderly person binomial. This allowed the identification of the main category--moving from reclusion to partial freedom: the experience of family caregivers for disabled elderly persons assisted in a Day Care Center.

High resolution renderings and interactive visualization of the 2006 Huntington Beach experiment

NASA Astrophysics Data System (ADS)

Im, T.; Nayak, A.; Keen, C.; Samilo, D.; Matthews, J.

2006-12-01

The Visualization Center at the Scripps Institution of Oceanography investigates innovative ways to represent graphically interactive 3D virtual landscapes and to produce high resolution, high quality renderings of Earth sciences data and the sensors and instruments used to collect the data . Among the Visualization Center's most recent work is the visualization of the Huntington Beach experiment, a study launched in July 2006 by the Southern California Ocean Observing System (http://www.sccoos.org/) to record and synthesize data of the Huntington Beach coastal region. Researchers and students at the Visualization Center created visual presentations that combine bathymetric data provided by SCCOOS with USGS aerial photography and with 3D polygonal models of sensors created in Maya into an interactive 3D scene using the Fledermaus suite of visualization tools (http://www.ivs3d.com). In addition, the Visualization Center has produced high definition (HD) animations of SCCOOS sensor instruments (e.g. REMUS, drifters, spray glider, nearshore mooring, OCSD/USGS mooring and CDIP mooring) using the Maya modeling and animation software and rendered over multiple nodes of the OptIPuter Visualization Cluster at Scripps. These visualizations are aimed at providing researchers with a broader context of sensor locations relative to geologic characteristics, to promote their use as an educational resource for informal education settings and increasing public awareness, and also as an aid for researchers' proposals and presentations. These visualizations are available for download on the Visualization Center website at http://siovizcenter.ucsd.edu/sccoos/hb2006.php.

Interactive initialization of heat flux parameters for numerical models using satellite temperature measurements

NASA Technical Reports Server (NTRS)

Carlson, T. N. (Principal Investigator)

1981-01-01

Efforts were made (1) to bring the image processing and boundary layer model operation into a completely interactive mode and (2) to test a method for determining the surface energy budget and surface moisture availability and thermal inertia on a scale appreciably larger than that of the city. A region a few hundred kilometers on a side centered over southern Indiana was examined.

Coupled Facility-Payload Vibration Modeling Improvements

NASA Technical Reports Server (NTRS)

Carnahan, Timothy M.; Kaiser, Michael A.

2015-01-01

A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at National Aeronautics and Space Administration/Goddard Space Flight Center an analysis is performed to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combined dynamics of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA/Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

The Multiple Correspondence Analysis Method and Brain Functional Connectivity: Its Application to the Study of the Non-linear Relationships of Motor Cortex and Basal Ganglia.

PubMed

Rodriguez-Sabate, Clara; Morales, Ingrid; Sanchez, Alberto; Rodriguez, Manuel

2017-01-01

The complexity of basal ganglia (BG) interactions is often condensed into simple models mainly based on animal data and that present BG in closed-loop cortico-subcortical circuits of excitatory/inhibitory pathways which analyze the incoming cortical data and return the processed information to the cortex. This study was aimed at identifying functional relationships in the BG motor-loop of 24 healthy-subjects who provided written, informed consent and whose BOLD-activity was recorded by MRI methods. The analysis of the functional interaction between these centers by correlation techniques and multiple linear regression showed non-linear relationships which cannot be suitably addressed with these methods. The multiple correspondence analysis (MCA), an unsupervised multivariable procedure which can identify non-linear interactions, was used to study the functional connectivity of BG when subjects were at rest. Linear methods showed different functional interactions expected according to current BG models. MCA showed additional functional interactions which were not evident when using lineal methods. Seven functional configurations of BG were identified with MCA, two involving the primary motor and somatosensory cortex, one involving the deepest BG (external-internal globus pallidum, subthalamic nucleus and substantia nigral), one with the input-output BG centers (putamen and motor thalamus), two linking the input-output centers with other BG (external pallidum and subthalamic nucleus), and one linking the external pallidum and the substantia nigral. The results provide evidence that the non-linear MCA and linear methods are complementary and should be best used in conjunction to more fully understand the nature of functional connectivity of brain centers.

Σ 3 (111 ) grain boundary of body-centered cubic Ti-Mo and Ti-V alloys: First-principles and model calculations

NASA Astrophysics Data System (ADS)

Yan, Jia-Yi; Ehteshami, Hossein; Korzhavyi, Pavel A.; Borgenstam, Annika

2017-07-01

The energetics and atomic structures of Σ 3 [1 1 ¯0 ] (111 ) grain boundary (GB) of body-centered cubic (bcc) Ti-Mo and Ti-V alloys are investigated using density-functional-theory calculations and virtual crystal approximation. The electron density in bcc structure and the atomic displacements and excess energy of the GB are correlated to bcc-ω phase stability. Model calculations based on pairwise interplanar interactions successfully reproduce the chemical part of GB energy. The chemical GB energy can be expressed as a sum of excess pairwise interactions between bcc (111) layers, which are obtained from Gaussian elimination of the total energies of a number of periodic structures. The energy associated with the relaxation near the GB is solved by numerical minimization using the derivatives of the excess interactions. Anharmonic interlayer interactions are necessary for obtaining accurate relaxation energy and excess GB volume from model calculations. The effect of GB on vibrational spectrum is also investigated. Segregation energies of B and Y to a substitutional site on the GB plane are calculated. Preliminary results suggest that Y tends to segregate, while B tends to antisegregate.

Center for Modeling of Turbulence and Transition (CMOTT). Research briefs: 1990

NASA Technical Reports Server (NTRS)

Povinelli, Louis A. (Compiler); Liou, Meng-Sing (Compiler); Shih, Tsan-Hsing (Compiler)

1991-01-01

Brief progress reports of the Center for Modeling of Turbulence and Transition (CMOTT) research staff from May 1990 to May 1991 are given. The objectives of the CMOTT are to develop, validate, and implement the models for turbulence and boundary layer transition in the practical engineering flows. The flows of interest are three dimensional, incompressible, and compressible flows with chemistry. The schemes being studied include the two-equation and algebraic Reynolds stress models, the full Reynolds stress (or second moment closure) models, the probability density function models, the Renormalization Group Theory (RNG) and Interaction Approximation (DIA), the Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS).

Finding a Middle Ground: Exploring the Impact of Patient- and Family-Centered Design on Nurse-Family Interactions in the Neuro ICU.

PubMed

Rippin, Allyn S; Zimring, Craig; Samuels, Owen; Denham, Megan E

2015-01-01

This comparative study of two adult neuro critical care units examined the impact of patient- and family-centered design on nurse-family interactions in a unit designed to increase family involvement. A growing evidence base suggests that the built environment can facilitate the delivery of patient- and family-centered care (PFCC). However, few studies examine how the PFCC model impacts the delivery of care, specifically the role of design in nurse-family interactions in the adult intensive care unit (ICU) from the perspective of the bedside nurse. Two neuro ICUs with the same patient population and staff, but with different layouts, were compared. Structured observations were conducted to assess changes in the frequency, location, and content of interactions between the two units. Discussions with staff provided additional insights into nurse attitudes, perceptions, and experiences caring for families. Nurses reported challenges balancing the needs of many stakeholders in a complex clinical environment, regardless of unit layout. However, differences in communication patterns between the clinician- and family-centered units were observed. More interactions were observed in nurse workstations in the PFCC unit, with most initiated by family. While the new unit was seen as more conducive to the delivery of PFCC, some nurses reported a loss of workspace control. Patient- and family-centered design created new spatial and temporal opportunities for nurse-family interactions in the adult ICU, thus supporting PFCC goals. However, greater exposure to unplanned family encounters may increase nurse stress without adequate spatial and organizational support. © The Author(s) 2015.

Theoretical research of the spin-Hamiltonian parameters for two rhombic W5+ centers in KTiOPO4 (KTP) crystal through a two-mechanism model

NASA Astrophysics Data System (ADS)

Mei, Yang; Chen, Bo-Wei; Wei, Chen-Fu; Zheng, Wen-Chen

2016-09-01

The high-order perturbation formulas based on the two-mechanism model are employed to calculate the spin-Hamiltonian parameters (g factors gi and hyperfine structure constants Ai, where i=x, y, z) for two approximately rhombic W5+ centers in KTiOPO4 (KTP) crystal. In the model, both the widely-applied crystal-field (CF) mechanism concerning the interactions of CF excited states with the ground state and the generally-neglected charge-transfer (CT) mechanism concerning the interactions of CT excited states with the ground state are included. The calculated results agree with the experimental values, and the signs of constants Ai are suggested. The calculations indicate that (i) for the high valence state dn ions in crystals, the contributions to spin-Hamiltonian parameters should take into account both the CF and CT mechanisms and (ii) the large g-shifts |Δgi | (=|gi-ge |, where ge≈ 2.0023) for W5+ centers in crystals are due to the large spin-orbit parameter of free W5+ ion.

A theory of germinal center B cell selection, division, and exit.

PubMed

Meyer-Hermann, Michael; Mohr, Elodie; Pelletier, Nadége; Zhang, Yang; Victora, Gabriel D; Toellner, Kai-Michael

2012-07-26

High-affinity antibodies are generated in germinal centers in a process involving mutation and selection of B cells. Information processing in germinal center reactions has been investigated in a number of recent experiments. These have revealed cell migration patterns, asymmetric cell divisions, and cell-cell interaction characteristics, used here to develop a theory of germinal center B cell selection, division, and exit (the LEDA model). According to this model, B cells selected by T follicular helper cells on the basis of successful antigen processing always return to the dark zone for asymmetric division, and acquired antigen is inherited by one daughter cell only. Antigen-retaining B cells differentiate to plasma cells and leave the germinal center through the dark zone. This theory has implications for the functioning of germinal centers because compared to previous models, high-affinity antibodies appear one day earlier and the amount of derived plasma cells is considerably larger. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

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

Filippov, A. V., E-mail: fav@triniti.ru

The interaction of two charged point macroparticles located in Wigner–Seitz cells of simple cubic (SC), body-centered cubic (BCC), or face-centered cubic (FCC) lattices in an equilibrium plasma has been studied within the Debye approximation or, more specifically, based on the linearized Poisson–Boltzmann model. The shape of the outer boundary is shown to exert a strong influence on the pattern of electrostatic interaction between the two macroparticles, which transforms from repulsion at small interparticle distances to attraction as the interparticle distance approaches half the length of the computational cell. The macroparticle pair interaction potential in an equilibrium plasma is shown tomore » be nevertheless the Debye one and purely repulsive for likely charged macroparticles.« less

Redox interactions in cytochrome c oxidase: from the "neoclassical" toward "modern" models.

PubMed Central

Hendler, R W; Westerhoff, H V

1992-01-01

Because of recent experimental data on the redox characteristics of cytochrome c oxidase and renewed interest in the role of cooperativity in energy coupling, the question of redox cooperativity in cytochrome c oxidase is reexamined. Extensive redox cooperativity between more than two redox centers, some of which are spectrally invisible, may be expected for this electron transfer coupled proton pump. Such cooperativity, however, cannot be revealed by the traditional potentiometric experiments based on a difference in absorbance between two wavelengths. Multiwavelength analyses utilizing singular value decomposition and second derivatives of absorbance vs. wavelength have revealed a stronger cooperativity than consistent with the "neoclassical" model, which allowed only for weak negative cooperativity between two equipotential one-electron centers. A thermodynamic analysis of redox cooperativity is developed, which includes the possibilities of strong cooperative redox interactions, the involvement of invisible redox centers, conformational changes, and monomer/dimer equilibrations. The experimental observation of an oxidation of one of the cytochromes (a3) with a decrease in applied redox potential is shown to require both strong negative cooperativity and the participation of more than two one-electron centers. A number of "modern" models are developed using the analytical approaches described in this paper. By testing with experimental data, some of these models are falsified, whereas some are retained with suggestions for further testing. PMID:1336989

Mean centering, multicollinearity, and moderators in multiple regression: The reconciliation redux.

PubMed

Iacobucci, Dawn; Schneider, Matthew J; Popovich, Deidre L; Bakamitsos, Georgios A

2017-02-01

In this article, we attempt to clarify our statements regarding the effects of mean centering. In a multiple regression with predictors A, B, and A × B (where A × B serves as an interaction term), mean centering A and B prior to computing the product term can clarify the regression coefficients (which is good) and the overall model fit R 2 will remain undisturbed (which is also good).

Integration of Dynamic Models in Range Operations

NASA Technical Reports Server (NTRS)

Bardina, Jorge; Thirumalainambi, Rajkumar

2004-01-01

This work addresses the various model interactions in real-time to make an efficient internet based decision making tool for Shuttle launch. The decision making tool depends on the launch commit criteria coupled with physical models. Dynamic interaction between a wide variety of simulation applications and techniques, embedded algorithms, and data visualizations are needed to exploit the full potential of modeling and simulation. This paper also discusses in depth details of web based 3-D graphics and applications to range safety. The advantages of this dynamic model integration are secure accessibility and distribution of real time information to other NASA centers.

Jet-Surface Interaction - High Aspect Ratio Nozzle Test: Test Summary

NASA Technical Reports Server (NTRS)

Brown, Clifford A.

2016-01-01

The Jet-Surface Interaction High Aspect Ratio Nozzle Test was conducted in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center in the fall of 2015. There were four primary goals specified for this test: (1) extend the current noise database for rectangular nozzles to higher aspect ratios, (2) verify data previously acquired at small-scale with data from a larger model, (3) acquired jet-surface interaction noise data suitable for creating verifying empirical noise models and (4) investigate the effect of nozzle septa on the jet-mixing and jet-surface interaction noise. These slides give a summary of the test with representative results for each goal.

Changes in social interaction over 20 years and the effects of community resources use among community-dwelling elderly persons.

PubMed

Watanabe, Kumi; Tanaka, Emiko; Wu, Bailiang; Kobayashi, Zyunko; Mochizuki, Yukiko; Kim, Yeon; Watanabe, Taeko; Okumura, Rika; Ito, Sumio; Anme, Tokie

2017-01-01

Objectives　Recently, social isolation has been reported to be a critical problem among Japanese elderly persons. However, few studies have compared social interaction in the past and the present or investigated its predictive factors. This study aimed to clarify the transitional changes in social interaction over 20 years and explore the factors related to social interaction focusing on the use of community resources.Methods　The participants were community-dwelling elderly persons aged 65 years and over. A survey was conducted 8 times from 1994 to 2014 in the suburban area of Tobishima, Japan. The Index of Social Interaction Scale was used and each subscale and the total score were calculated. Subsequently, the 2014 scores were compared with the 1994 scores using the Wilcoxon rank sum test. Logistic regression analysis was conducted to clarify the factors related to social interaction, focusing on the association between the use of community resources (local elderly management center, health care center, health promotion facility, library) in 2011 and social interaction 3 years later. Age, gender, disease, and mobility were also entered into the model as control variables.Results　Comparing social interaction in 1994 and 2014, total scores were found to have significantly increased in all age groups. Independence scores significantly increased in the overall group and in females aged 75-84. Curiosity scores also increased in both males and females. These results show that social interaction has increased over 2 decades. In addition, the use of local elderly management and health care centers, and health promotion facilities was associated with total social interaction scores 3 years later.Conclusion　The current study clarified changes in social interaction, both comprehensively and for each of its aspects, among community-dwelling elderly adults. Increasing social isolation has been reported in recent years; however, the current study showed that social interaction, including social curiosity and independence, has increased over 20 years. The effect of preventive intervention in local elderly management centers, health care centers, and health promotion facilities may be one of the causes for this increase.

Business Performer-Centered Design of User Interfaces

NASA Astrophysics Data System (ADS)

Sousa, Kênia; Vanderdonckt, Jean

Business Performer-Centered Design of User Interfaces is a new design methodology that adopts business process (BP) definition and a business performer perspective for managing the life cycle of user interfaces of enterprise systems. In this methodology, when the organization has a business process culture, the business processes of an organization are firstly defined according to a traditional methodology for this kind of artifact. These business processes are then transformed into a series of task models that represent the interactive parts of the business processes that will ultimately lead to interactive systems. When the organization has its enterprise systems, but not yet its business processes modeled, the user interfaces of the systems help derive tasks models, which are then used to derive the business processes. The double linking between a business process and a task model, and between a task model and a user interface model makes it possible to ensure traceability of the artifacts in multiple paths and enables a more active participation of business performers in analyzing the resulting user interfaces. In this paper, we outline how a human-perspective is used tied to a model-driven perspective.

A nucleobase-centered coarse-grained representation for structure prediction of RNA motifs.

PubMed

Poblete, Simón; Bottaro, Sandro; Bussi, Giovanni

2018-02-28

We introduce the SPlit-and-conQueR (SPQR) model, a coarse-grained (CG) representation of RNA designed for structure prediction and refinement. In our approach, the representation of a nucleotide consists of a point particle for the phosphate group and an anisotropic particle for the nucleoside. The interactions are, in principle, knowledge-based potentials inspired by the $\\mathcal {E}$SCORE function, a base-centered scoring function. However, a special treatment is given to base-pairing interactions and certain geometrical conformations which are lost in a raw knowledge-based model. This results in a representation able to describe planar canonical and non-canonical base pairs and base-phosphate interactions and to distinguish sugar puckers and glycosidic torsion conformations. The model is applied to the folding of several structures, including duplexes with internal loops of non-canonical base pairs, tetraloops, junctions and a pseudoknot. For the majority of these systems, experimental structures are correctly predicted at the level of individual contacts. We also propose a method for efficiently reintroducing atomistic detail from the CG representation.

SPATIAL PATTERNS OF ARRESTS, POLICE ASSAULT, AND ADDICTION TREATMENT CENTER LOCATIONS IN TIJUANA, MEXICO

PubMed Central

Werb, D; Strathdee, SA; Vera, A; Arredondo, J; Beletsky, L; Gonzalez-Zuniga, P; Gaines, T

2016-01-01

Aims In the context of a public health-oriented drug policy reform in Mexico, we assessed the spatial distribution of police encounters among people who inject drugs (PWID) in Tijuana; determined the association between these encounters and the location of addiction treatment centers; and explored the association between police encounters and treatment access. Design Geographically weighted regression (GWR) and logistic regression analysis using prospective spatial data from a community-recruited cohort of PWID in Tijuana and official geographic arrest data from the Tijuana Municipal Police Department. Setting Tijuana, Mexico. Participants 608 participants (median age 37; 28.4% female) in the prospective Proyecto El Cuete cohort study recruited between January and December 2011. Measurements We compared the mean distance of police encounters and a randomly distributed set of events to treatment centers. GWR was undertaken to model the spatial relationship between police interactions and treatment centers. Logistic regression analysis was used to investigate factors associated with reporting police interactions. Findings During the study period, 27.5% of police encounters occurred within 500 meters of treatment centers. The GWR model suggested spatial correlation between encounters and treatment centers (Global R2 = 0.53). Reporting a need for addiction treatment was associated with reporting arrest and police assault (Adjusted Odds Ratio = 2.74, 95% Confidence Interval [CI]: 1.25–6.02, p = 0.012). Conclusions A geospatial analysis suggests that in Mexico, people who inject drugs are at greater risk of being a victim of police violence if they consider themselves in need of addiction treatment, and their interactions with police appear to be more frequent around treatment centres. PMID:26879179

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande.

PubMed

Kachulis, C; Abe, K; Bronner, C; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kato, Y; Kishimoto, Y; Marti, Ll; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Okajima, Y; Orii, A; Pronost, G; Sekiya, H; Shiozawa, M; Sonoda, Y; Takeda, A; Takenaka, A; Tanaka, H; Tasaka, S; Tomura, T; Akutsu, R; Kajita, T; Kaneyuki, K; Nishimura, Y; Okumura, K; Tsui, K M; Labarga, L; Fernandez, P; Blaszczyk, F D M; Gustafson, J; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Tobayama, S; Goldhaber, M; Elnimr, M; Kropp, W R; Mine, S; Locke, S; Weatherly, P; Smy, M B; Sobel, H W; Takhistov, V; Ganezer, K S; Hill, J; Kim, J Y; Lim, I T; Park, R G; Himmel, A; Li, Z; O'Sullivan, E; Scholberg, K; Walter, C W; Ishizuka, T; Nakamura, T; Jang, J S; Choi, K; Learned, J G; Matsuno, S; Smith, S N; Amey, J; Litchfield, R P; Ma, W Y; Uchida, Y; Wascko, M O; Cao, S; Friend, M; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Abe, K E; Hasegawa, M; Suzuki, A T; Takeuchi, Y; Yano, T; Hayashino, T; Hiraki, T; Hirota, S; Huang, K; Jiang, M; Nakamura, K E; Nakaya, T; Quilain, B; Patel, N D; Wendell, R A; Anthony, L H V; McCauley, N; Pritchard, A; Fukuda, Y; Itow, Y; Murase, M; Muto, F; Mijakowski, P; Frankiewicz, K; Jung, C K; Li, X; Palomino, J L; Santucci, G; Vilela, C; Wilking, M J; Yanagisawa, C; Ito, S; Fukuda, D; Ishino, H; Kibayashi, A; Koshio, Y; Nagata, H; Sakuda, M; Xu, C; Kuno, Y; Wark, D; Di Lodovico, F; Richards, B; Tacik, R; Kim, S B; Cole, A; Thompson, L; Okazawa, H; Choi, Y; Ito, K; Nishijima, K; Koshiba, M; Totsuka, Y; Suda, Y; Yokoyama, M; Calland, R G; Hartz, M; Martens, K; Simpson, C; Suzuki, Y; Vagins, M R; Hamabe, D; Kuze, M; Yoshida, T; Ishitsuka, M; Martin, J F; Nantais, C M; Tanaka, H A; Konaka, A; Chen, S; Wan, L; Zhang, Y; Wilkes, R J; Minamino, A

2018-06-01

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

NASA Astrophysics Data System (ADS)

Kachulis, C.; Abe, K.; Bronner, C.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kato, Y.; Kishimoto, Y.; Marti, Ll.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakano, Y.; Nakayama, S.; Okajima, Y.; Orii, A.; Pronost, G.; Sekiya, H.; Shiozawa, M.; Sonoda, Y.; Takeda, A.; Takenaka, A.; Tanaka, H.; Tasaka, S.; Tomura, T.; Akutsu, R.; Kajita, T.; Kaneyuki, K.; Nishimura, Y.; Okumura, K.; Tsui, K. M.; Labarga, L.; Fernandez, P.; Blaszczyk, F. d. M.; Gustafson, J.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tobayama, S.; Goldhaber, M.; Elnimr, M.; Kropp, W. R.; Mine, S.; Locke, S.; Weatherly, P.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Ganezer, K. S.; Hill, J.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Ishizuka, T.; Nakamura, T.; Jang, J. S.; Choi, K.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Amey, J.; Litchfield, R. P.; Ma, W. Y.; Uchida, Y.; Wascko, M. O.; Cao, S.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Abe, KE.; Hasegawa, M.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Hayashino, T.; Hiraki, T.; Hirota, S.; Huang, K.; Jiang, M.; Nakamura, KE.; Nakaya, T.; Quilain, B.; Patel, N. D.; Wendell, R. A.; Anthony, L. H. V.; McCauley, N.; Pritchard, A.; Fukuda, Y.; Itow, Y.; Murase, M.; Muto, F.; Mijakowski, P.; Frankiewicz, K.; Jung, C. K.; Li, X.; Palomino, J. L.; Santucci, G.; Vilela, C.; Wilking, M. J.; Yanagisawa, C.; Ito, S.; Fukuda, D.; Ishino, H.; Kibayashi, A.; Koshio, Y.; Nagata, H.; Sakuda, M.; Xu, C.; Kuno, Y.; Wark, D.; Di Lodovico, F.; Richards, B.; Tacik, R.; Kim, S. B.; Cole, A.; Thompson, L.; Okazawa, H.; Choi, Y.; Ito, K.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Calland, R. G.; Hartz, M.; Martens, K.; Simpson, C.; Suzuki, Y.; Vagins, M. R.; Hamabe, D.; Kuze, M.; Yoshida, T.; Ishitsuka, M.; Martin, J. F.; Nantais, C. M.; Tanaka, H. A.; Konaka, A.; Chen, S.; Wan, L.; Zhang, Y.; Wilkes, R. J.; Minamino, A.; Super-Kamiokande Collaboration

2018-06-01

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.

The North Atlantic Oscillation and the ITCZ in a climate simulation

NASA Astrophysics Data System (ADS)

Cavalcanti, I. F. A.; Souza, P.

2009-04-01

The North Atlantic Oscillation (NAO) and the Atlantic Intertropical Convergence Zone (ITCZ) features are analyzed in a climate simulation with the CPTEC/COLA AGCM. The CPTEC/COLA AGCM reproduces the ITCZ seasonal north-south displacement as well as the seasonal east-west intensity, but the model overestimates the convection. The two phases of NAO are well simulated in the four seasons and also the largest intensity in DJF. The main mode of atmospheric variability considering the North and South Atlantic region, which displays a shifting of the NAO centers and a center of action over South Atlantic to the south of Africa is also reproduced. This mode, in DJF, is associated with the north-south ITCZ displacement in April, in the observed data. The displacement of the NAO centers southwestward allows the increase of pressure over the tropical North Atlantic Ocean and the increase of trade winds and displacement of the confluence and convergence zone southwards. The opposite occurs when the centers are displaced northeastward. The model Atlantic ITCZ position in April is associated with the anomalous (observed) Atlantic SST and the southward displacement of the confluence zone, but the simulated atmospheric features in DJF does not display the main mode of variability, as in the observations. This occurs due to the lack of interaction between the atmosphere and ocean in the atmospheric model. While in the observations the physical mechanism that links the NAO centers of action to the ITCZ position is the ocean-atmosphere interaction, from DJF to April, the atmospheric model responds to the prescribed SST at the same month, in April.

Interactive display of molecular models using a microcomputer system

NASA Technical Reports Server (NTRS)

Egan, J. T.; Macelroy, R. D.

1980-01-01

A simple, microcomputer-based, interactive graphics display system has been developed for the presentation of perspective views of wire frame molecular models. The display system is based on a TERAK 8510a graphics computer system with a display unit consisting of microprocessor, television display and keyboard subsystems. The operating system includes a screen editor, file manager, PASCAL and BASIC compilers and command options for linking and executing programs. The graphics program, written in USCD PASCAL, involves the centering of the coordinate system, the transformation of centered model coordinates into homogeneous coordinates, the construction of a viewing transformation matrix to operate on the coordinates, clipping invisible points, perspective transformation and scaling to screen coordinates; commands available include ZOOM, ROTATE, RESET, and CHANGEVIEW. Data file structure was chosen to minimize the amount of disk storage space. Despite the inherent slowness of the system, its low cost and flexibility suggests general applicability.

Fostering the development of effective person-centered healthcare communication skills: an interprofessional shared learning model.

PubMed

Cavanaugh, James T; Konrad, Shelley Cohen

2012-01-01

To describe the implementation of an interprofessional shared learning model designed to promote the development of person-centered healthcare communication skills. Master of social work (MSW) and doctor of physical therapy (DPT) degree students. The model used evidence-based principles of effective healthcare communication and shared learning methods; it was aligned with student learning outcomes contained in MSW and DPT curricula. Students engaged in 3 learning sessions over 2 days. Sessions involved interactive reflective learning, simulated role-modeling with peer assessment, and context-specific practice of communication skills. The perspective of patients/clients was included in each learning activity. Activities were evaluated through narrative feedback. Students valued opportunities to learn directly from each other and from healthcare consumers. Important insights and directions for future interprofessional learning experiences were gleaned from model implementation. The interprofessional shared learning model shows promise as an effective method for developing person-centered communication skills.

New evidence on the validity of the Arnett Caregiver Interaction Scale: Results from the Early Childhood Longitudinal Study-Birth Cohort

PubMed Central

Colwell, Nicole; Gordon, Rachel A.; Fujimoto, Ken; Kaestner, Robert; Korenman, Sanders

2013-01-01

The Arnett Caregiver Interaction Scale (CIS) has been widely used in research studies to measure the quality of caregiver–child interactions. The scale was modeled on a well-established theory of parenting, but there are few psychometric studies of its validity. We applied factor analyses and item response theory methods to assess the psychometric properties of the Arnett CIS in a national sample of toddlers in home-based care and preschoolers in center-based care from the Early Childhood Longitudinal Study-Birth Cohort. We found that a bifactor structure (one common factor and a second set of specific factors) best fits the data. In the Arnett CIS, the bifactor model distinguishes a common substantive dimension from two methodological dimensions (for positively and negatively oriented items). Despite the good fit of this model, the items are skewed (most teachers/caregivers display positive interactions with children) and, as a result, the Arnett CIS is not well suited to distinguish between caregivers who are “highly” versus “moderately” positive in their interactions with children, according to the items on the scale. Regression-adjusted associations between the Arnett CIS and child outcomes are small, especially for preschoolers in centers. We encourage future scale development work on measures of child care quality by early childhood scholars. PMID:24058264

Interactions of atomic hydrogen with amorphous SiO2

NASA Astrophysics Data System (ADS)

Yue, Yunliang; Wang, Jianwei; Zhang, Yuqi; Song, Yu; Zuo, Xu

2018-03-01

Dozens of models are investigated by the first-principles calculations to simulate the interactions of an atomic hydrogen with a defect-free random network of amorphous SiO2 (a-SiO2) and oxygen vacancies. A wide variety of stable configurations are discovered due to the disorder of a-SiO2, and their structures, charges, magnetic moments, spin densities, and density of states are calculated. The atomic hydrogen interacts with the defect-free a-SiO2 in positively or negatively charged state, and produces the structures absent in crystalline SiO2. It passivates the neutral oxygen vacancies and generates two neutral hydrogenated E‧ centers with different Si dangling bond projections. Electron spin resonance parameters, including Fermi contacts, and g-tensors, are calculated for these centers. The atomic hydrogen interacts with the positive oxygen vacancies in dimer configuration, and generate four different positive hydrogenated defects, two of which are puckered like the Eγ‧ centers. This research helps to understand the interactions between an atomic hydrogen, and defect-free a-SiO2 and oxygen vacancies, which may generate the hydrogen-complexed defects that play a key role in the degeneration of silicon/silica-based microelectronic devices.

POD Analysis of Jet-Plume/Afterbody-Wake Interaction

NASA Astrophysics Data System (ADS)

Murray, Nathan E.; Seiner, John M.; Jansen, Bernard J.; Gui, Lichuan; Sockwell, Shuan; Joachim, Matthew

2009-11-01

The understanding of the flow physics in the base region of a powered rocket is one of the keys to designing the next generation of reusable launchers. The base flow features affect the aerodynamics and the heat loading at the base of the vehicle. Recent efforts at the National Center for Physical Acoustics at the University of Mississippi have refurbished two models for studying jet-plume/afterbody-wake interactions in the NCPA's 1-foot Tri-Sonic Wind Tunnel Facility. Both models have a 2.5 inch outer diameter with a nominally 0.5 inch diameter centered exhaust nozzle. One of the models is capable of being powered with gaseous H2 and O2 to study the base flow in a fully combusting senario. The second model uses hi-pressure air to drive the exhaust providing an unheated representative flow field. This unheated model was used to acquire PIV data of the base flow. Subsequently, a POD analysis was performed to provide a first look at the large-scale structures present for the interaction between an axisymmetric jet and an axisymmetric afterbody wake. PIV and Schlieren data are presented for a single jet-exhaust to free-stream flow velocity along with the POD analysis of the base flow field.

Wave-Ice interaction in the Marginal Ice Zone: Toward a Wave-Ocean-Ice Coupled Modeling System

DTIC Science & Technology

2015-09-30

MIZ using WW3 (3 frequency bins, ice retreat in August and ice advance in October); Blue (solid): Based on observations near Antarctica by Meylan...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Wave- Ice interaction in the Marginal Ice Zone: Toward a...Wave-Ocean- Ice Coupled Modeling System W. E. Rogers Naval Research Laboratory, Code 7322 Stennis Space Center, MS 39529 phone: (228) 688-4727

Point sources from dissipative dark matter

NASA Astrophysics Data System (ADS)

Agrawal, Prateek; Randall, Lisa

2017-12-01

If a component of dark matter has dissipative interactions, it can cool to form compact astrophysical objects with higher density than that of conventional cold dark matter (sub)haloes. Dark matter annihilations might then appear as point sources, leading to novel morphology for indirect detection. We explore dissipative models where interaction with the Standard Model might provide visible signals, and show how such objects might give rise to the observed excess in gamma rays arising from the galactic center.

Patterns of Risk Using an Integrated Spatial Multi-Hazard Model (PRISM Model)

EPA Science Inventory

Multi-hazard risk assessment has long centered on small scale needs, whereby a single community or group of communities’ exposures are assessed to determine potential mitigation strategies. While this approach has advanced the understanding of hazard interactions, it is li...

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

Nesterov, V. A., E-mail: archerix@ukpost.ua

On the basis of the energy-density method, the effect of simultaneously taking into account the Pauli exclusion principle and the monopole and quadrupole polarizations of interacting nuclei on their interaction potential is considered for the example of the {sup 16}O + {sup 16}O system by using the wave function for the two-center shell model. The calculations performed in the adiabatic approximation reveal that the inclusion of the Pauli exclusion principle and the polarization of interacting nuclei, especially their quadrupole polarization, has a substantial effect on the potential of the nucleus-nucleus interaction.

Land Processes Distributed Active Archive Center (LP DAAC) 25th Anniversary Recognition "A Model for Government Partnerships". LP DAAC "History and a Look Forward"

NASA Technical Reports Server (NTRS)

Behnke, Jeanne; Doescher, Chris

2015-01-01

This presentation discusses 25 years of interactions between NASA and the USGS to manage a Land Processes Distributed Active Archive Center (LPDAAC) for the purpose of providing users access to NASA's rich collection of Earth Science data. The presentation addresses challenges, efforts and metrics on the performance.

Using the Multicultural Family Support Centers and Adjustment among Interethnic and Interracial Families in South Korea

ERIC Educational Resources Information Center

Chung, Grace H.; Yoo, Joan P.

2013-01-01

The present study proposes a model of using the Multicultural Family Support Centers and adjustment among foreign brides and their interethnic and interracial families in South Korea based on the narratives of 10 foreign brides married to Korean men and 11 service providers who directly interact with these women and their families. The results…

Modeling the refraction of microbaroms by the winds of a large maritime storm.

PubMed

Blom, Philip; Waxler, Roger

2017-12-01

Continuous infrasonic signals produced by the ocean surface interacting with the atmosphere, termed microbaroms, are known to be generated by a number of phenomena including large maritime storms. Storm generated microbaroms exhibit axial asymmetry when observed at locations far from the storm due to the source location being offset from the storm center. Because of this offset, a portion of the microbarom energy will radiate towards the storm center and interact with the winds in the region. Detailed here are predictions for the propagation of microbaroms through an axisymmetric, three-dimensional model storm. Geometric propagation methods have been utilized and the predicted horizontal refraction is found to produce signals that appear to emanate from a virtual source near the storm center when observed far from the storm. This virtual source near the storm center is expected to be observed only from a limited arc around the storm system with increased extent associated with more intense wind fields. This result implies that identifying the extent of the arc observing signal from the virtual source could provide a means to estimate the wind structure using infrasonic observations far from the storm system.

Leveraging Terminology Services for Extract-Transform-Load Processes: A User-Centered Approach

PubMed Central

Peterson, Kevin J.; Jiang, Guoqian; Brue, Scott M.; Liu, Hongfang

2016-01-01

Terminology services serve an important role supporting clinical and research applications, and underpin a diverse set of processes and use cases. Through standardization efforts, terminology service-to-system interactions can leverage well-defined interfaces and predictable integration patterns. Often, however, users interact more directly with terminologies, and no such blueprints are available for describing terminology service-to-user interactions. In this work, we explore the main architecture principles necessary to build a user-centered terminology system, using an Extract-Transform-Load process as our primary usage scenario. To analyze our architecture, we present a prototype implementation based on the Common Terminology Services 2 (CTS2) standard using the Patient-Centered Network of Learning Health Systems (LHSNet) project as a concrete use case. We perform a preliminary evaluation of our prototype architecture using three architectural quality attributes: interoperability, adaptability and usability. We find that a design-time focus on user needs, cognitive models, and existing patterns is essential to maximize system utility. PMID:28269898

Limiting assumptions in molecular modeling: electrostatics.

PubMed

Marshall, Garland R

2013-02-01

Molecular mechanics attempts to represent intermolecular interactions in terms of classical physics. Initial efforts assumed a point charge located at the atom center and coulombic interactions. It is been recognized over multiple decades that simply representing electrostatics with a charge on each atom failed to reproduce the electrostatic potential surrounding a molecule as estimated by quantum mechanics. Molecular orbitals are not spherically symmetrical, an implicit assumption of monopole electrostatics. This perspective reviews recent evidence that requires use of multipole electrostatics and polarizability in molecular modeling.

National Centers for Environmental Prediction

Science.gov Websites

Reference List Table of Contents NCEP OPERATIONAL MODEL FORECAST GRAPHICS PARALLEL/EXPERIMENTAL MODEL Developmental Air Quality Forecasts and Verification Back to Table of Contents 2. PARALLEL/EXPERIMENTAL GRAPHICS VERIFICATION (GRID VS.OBS) WEB PAGE (NCEP EXPERIMENTAL PAGE, INTERNAL USE ONLY) Interactive web page tool for

Influence of World and Gravity Model Selection on Surface Interacting Vehicle Simulations

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2007-01-01

A vehicle simulation is surface-interacting if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. Modeling of gravity is an influential environmental factor for surface-interacting simulations. Gravity is the free-fall acceleration observed from a world-fixed frame that rotates with the world. Thus, gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. In surface-interacting simulations, the fidelity of gravity at heights above the surface is more significant than gravity fidelity at locations in inertial space. A surface-interacting simulation cannot treat the gravity model separately from the world model, which simulates the motion and shape of the world. The world model's simulation of the world's rotation, or lack thereof, produces the centrifugal acceleration component of gravity. The world model s reproduction of the world's shape will produce different positions relative to the world center for a given height above the surface. These differences produce variations in the gravitation component of gravity. This paper examines the actual performance of world and gravity/gravitation pairs in a simulation using the Earth.

Human Factors Model

NASA Technical Reports Server (NTRS)

1993-01-01

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

A nucleobase-centered coarse-grained representation for structure prediction of RNA motifs

PubMed Central

Poblete, Simón; Bottaro, Sandro; Bussi, Giovanni

2018-01-01

Abstract We introduce the SPlit-and-conQueR (SPQR) model, a coarse-grained (CG) representation of RNA designed for structure prediction and refinement. In our approach, the representation of a nucleotide consists of a point particle for the phosphate group and an anisotropic particle for the nucleoside. The interactions are, in principle, knowledge-based potentials inspired by the \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\mathcal {E}$\\end{document}SCORE function, a base-centered scoring function. However, a special treatment is given to base-pairing interactions and certain geometrical conformations which are lost in a raw knowledge-based model. This results in a representation able to describe planar canonical and non-canonical base pairs and base–phosphate interactions and to distinguish sugar puckers and glycosidic torsion conformations. The model is applied to the folding of several structures, including duplexes with internal loops of non-canonical base pairs, tetraloops, junctions and a pseudoknot. For the majority of these systems, experimental structures are correctly predicted at the level of individual contacts. We also propose a method for efficiently reintroducing atomistic detail from the CG representation. PMID:29272539

Students' Perceptions and Supervisors' Rating as Assessments of Interactive-Constructivist Science Teaching in Elementary School.

ERIC Educational Resources Information Center

Shymansky, James A.; Yore, Larry D.; Henriques, Laura; Dunkhase, John A.; Bancroft, Jean

This study took place within the context of a four-year local systemic reform effort collaboratively undertaken by the Science Education Center at the University of Iowa and the Iowa City Community School District. The goal of the project was to move teachers towards an interactive-constructivist model of teaching and learning that assumes a…

Glass transition temperature of polymer nano-composites with polymer and filler interactions

NASA Astrophysics Data System (ADS)

Hagita, Katsumi; Takano, Hiroshi; Doi, Masao; Morita, Hiroshi

2012-02-01

We systematically studied versatile coarse-grained model (bead spring model) to describe filled polymer nano-composites for coarse-grained (Kremer-Grest model) molecular dynamics simulations. This model consists of long polymers, crosslink, and fillers. We used the hollow structure as the filler to describe rigid spherical fillers with small computing costs. Our filler model consists of surface particles of icosahedra fullerene structure C320 and a repulsive force from the center of the filler is applied to the surface particles in order to make a sphere and rigid. The filler's diameter is 12 times of beads of the polymers. As the first test of our model, we study temperature dependence of volumes of periodic boundary conditions under constant pressures through NPT constant Andersen algorithm. It is found that Glass transition temperature (Tg) decrease with increasing filler's volume fraction for the case of repulsive interaction between polymer and fillers and Tg weakly increase for attractive interaction.

Interaction of a turbulent vortex with a lifting surface

NASA Technical Reports Server (NTRS)

Lee, D. J.; Roberts, L.

1985-01-01

The impulsive noise due to blade-vortex-interaction is analyzing in the time domain for the extreme case when the blade cuts through the center of the vortex core with the assumptions of no distortion of the vortex path or of the vortex core. An analytical turbulent vortex core model, described in terms of the tip aerodynamic parameters, is used and its effects on the unsteady loading and maximum acoustic pressure during the interaction are determined.

Interaction of a magnet and a point charge: Unrecognized internal electromagnetic momentum

NASA Astrophysics Data System (ADS)

Boyer, Timothy H.

2015-05-01

Whereas nonrelativistic mechanics always connects the total momentum of a system to the motion of the center of mass, relativistic systems, such as interacting electromagnetic charges, can have internal linear momentum in the absence of motion of the system's center of energy. This internal linear momentum of a system is related to the controversial concept of "hidden momentum." We suggest that the term "hidden momentum" be abandoned. Here, we use the relativistic conservation law for the center of energy to give an unambiguous definition of the "internal momentum of a system," and then we exhibit this internal momentum for the system of a magnet (modeled as a circular ring of moving charges) and a distant static point charge. The calculations provide clear illustrations of this system for three cases: (a) the moving charges of the magnet are assumed to continue in their unperturbed motion; (b) the moving charges of the magnet are free to accelerate but have no mutual interactions; and (c) the moving charges of the magnet are free to accelerate and also interact with each other. When the current-carrying charges of the magnet are allowed to interact, the magnet itself will contain internal electromagnetic linear momentum, something that has not been described clearly in the research and teaching literature.

To center or not to center? Investigating inertia with a multilevel autoregressive model.

PubMed

Hamaker, Ellen L; Grasman, Raoul P P P

2014-01-01

Whether level 1 predictors should be centered per cluster has received considerable attention in the multilevel literature. While most agree that there is no one preferred approach, it has also been argued that cluster mean centering is desirable when the within-cluster slope and the between-cluster slope are expected to deviate, and the main interest is in the within-cluster slope. However, we show in a series of simulations that if one has a multilevel autoregressive model in which the level 1 predictor is the lagged outcome variable (i.e., the outcome variable at the previous occasion), cluster mean centering will in general lead to a downward bias in the parameter estimate of the within-cluster slope (i.e., the autoregressive relationship). This is particularly relevant if the main question is whether there is on average an autoregressive effect. Nonetheless, we show that if the main interest is in estimating the effect of a level 2 predictor on the autoregressive parameter (i.e., a cross-level interaction), cluster mean centering should be preferred over other forms of centering. Hence, researchers should be clear on what is considered the main goal of their study, and base their choice of centering method on this when using a multilevel autoregressive model.

To center or not to center? Investigating inertia with a multilevel autoregressive model

PubMed Central

Hamaker, Ellen L.; Grasman, Raoul P. P. P.

2015-01-01

Whether level 1 predictors should be centered per cluster has received considerable attention in the multilevel literature. While most agree that there is no one preferred approach, it has also been argued that cluster mean centering is desirable when the within-cluster slope and the between-cluster slope are expected to deviate, and the main interest is in the within-cluster slope. However, we show in a series of simulations that if one has a multilevel autoregressive model in which the level 1 predictor is the lagged outcome variable (i.e., the outcome variable at the previous occasion), cluster mean centering will in general lead to a downward bias in the parameter estimate of the within-cluster slope (i.e., the autoregressive relationship). This is particularly relevant if the main question is whether there is on average an autoregressive effect. Nonetheless, we show that if the main interest is in estimating the effect of a level 2 predictor on the autoregressive parameter (i.e., a cross-level interaction), cluster mean centering should be preferred over other forms of centering. Hence, researchers should be clear on what is considered the main goal of their study, and base their choice of centering method on this when using a multilevel autoregressive model. PMID:25688215

Lower Bound on the Mean Square Displacement of Particles in the Hard Disk Model

NASA Astrophysics Data System (ADS)

Richthammer, Thomas

2016-08-01

The hard disk model is a 2D Gibbsian process of particles interacting via pure hard core repulsion. At high particle density the model is believed to show orientational order, however, it is known not to exhibit positional order. Here we investigate to what extent particle positions may fluctuate. We consider a finite volume version of the model in a box of dimensions 2 n × 2 n with arbitrary boundary configuration, and we show that the mean square displacement of particles near the center of the box is bounded from below by c log n. The result generalizes to a large class of models with fairly arbitrary interaction.

Independent Living & Disability Policy in the Netherlands: Three Models of Residential Care & Independent Living. Monograph Number Twenty-Seven.

ERIC Educational Resources Information Center

DeJong, Gerben

The monograph examines the way in which the Netherlands' three-part system of residential care and independent living (IL) for people with physical disabilities interacts with the country's health and social welfare systems. The three-part system comprises: the residential center model, the clustered housing model, and the independent housing…

Accounting for center in the Early External Cephalic Version trials: an empirical comparison of statistical methods to adjust for center in a multicenter trial with binary outcomes.

PubMed

Reitsma, Angela; Chu, Rong; Thorpe, Julia; McDonald, Sarah; Thabane, Lehana; Hutton, Eileen

2014-09-26

Clustering of outcomes at centers involved in multicenter trials is a type of center effect. The Consolidated Standards of Reporting Trials Statement recommends that multicenter randomized controlled trials (RCTs) should account for center effects in their analysis, however most do not. The Early External Cephalic Version (EECV) trials published in 2003 and 2011 stratified by center at randomization, but did not account for center in the analyses, and due to the nature of the intervention and number of centers, may have been prone to center effects. Using data from the EECV trials, we undertook an empirical study to compare various statistical approaches to account for center effect while estimating the impact of external cephalic version timing (early or delayed) on the outcomes of cesarean section, preterm birth, and non-cephalic presentation at the time of birth. The data from the EECV pilot trial and the EECV2 trial were merged into one dataset. Fisher's exact method was used to test the overall effect of external cephalic version timing unadjusted for center effects. Seven statistical models that accounted for center effects were applied to the data. The models included: i) the Mantel-Haenszel test, ii) logistic regression with fixed center effect and fixed treatment effect, iii) center-size weighted and iv) un-weighted logistic regression with fixed center effect and fixed treatment-by-center interaction, iv) logistic regression with random center effect and fixed treatment effect, v) logistic regression with random center effect and random treatment-by-center interaction, and vi) generalized estimating equations. For each of the three outcomes of interest approaches to account for center effect did not alter the overall findings of the trial. The results were similar for the majority of the methods used to adjust for center, illustrating the robustness of the findings. Despite literature that suggests center effect can change the estimate of effect in multicenter trials, this empirical study does not show a difference in the outcomes of the EECV trials when accounting for center effect. The EECV2 trial was registered on 30 July 30 2005 with Current Controlled Trials: ISRCTN 56498577.

The imbalanced brain: from normal behavior to schizophrenia.

PubMed

Grossberg, S

2000-07-15

An outstanding problem in psychiatry concerns how to link discoveries about the pharmacological, neurophysiological, and neuroanatomical substrates of mental disorders to the abnormal behaviors that they control. A related problem concerns how to understand abnormal behaviors on a continuum with normal behaviors. During the past few decades, neural models have been developed of how normal cognitive and emotional processes learn from the environment, focus attention and act upon motivationally important events, and cope with unexpected events. When arousal or volitional signals in these models are suitably altered, they give rise to symptoms that strikingly resemble negative and positive symptoms of schizophrenia, including flat affect, impoverishment of will, attentional problems, loss of a theory of mind, thought derailment, hallucinations, and delusions. This article models how emotional centers of the brain, such as the amygdala, interact with sensory and prefrontal cortices (notably ventral, or orbital, prefrontal cortex) to generate affective states, attend to motivationally salient sensory events, and elicit motivated behaviors. Closing this feedback loop between cognitive and emotional centers is predicted to generate a cognitive-emotional resonance that can support conscious awareness. When such emotional centers become depressed, negative symptoms of schizophrenia emerge in the model. Such emotional centers are modeled as opponent affective processes, such as fear and relief, whose response amplitude and sensitivity are calibrated by an arousal level and chemical transmitters that slowly inactivate, or habituate, in an activity-dependent way. These opponent processes exhibit an Inverted-U, whereby behavior becomes depressed if the arousal level is chosen too large or too small. The negative symptoms are owing to the way in which the depressed opponent process interacts with other circuits throughout the brain.

Cookie-Ases: Interactive Models for Teaching Genotype-Phenotype Relationships

ERIC Educational Resources Information Center

Seipelt, Rebecca L.

2006-01-01

Several hands-on and wet laboratory activities have been proposed to model the genetic concepts of genotypes and phenotypes and their relationship. The exercise presented in this article is a novel, time effective, student-centered, role-playing activity in which students learn about the intricate connection between genotype and phenotype by…

Silencing the Center: Local Knowledge and Imported Model in Learning Disabilities

ERIC Educational Resources Information Center

Bazna, Maysaa

2009-01-01

This qualitative study investigates the interaction between local and imported knowledges in a specific case of transnational importation; the whole-sale importation of the American medical learning disabilities (LDs) model in Kuwait. A discourse analysis of the narratives of local educators at the only school for LDs in the country reveals a…

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

EPA Science Inventory

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

New Integrated Testing System for the Validation of Vehicle-Snow Interaction Models

DTIC Science & Technology

2010-08-06

are individual wheel speeds, accelerator pedal position, vehicle speed, yaw rate, lateral acceleration, steering wheel angle and brake ...forces and moments at each wheel center, vehicle body slip angle , speed, acceleration, yaw rate, roll, and pitch. The profilometer has a 3-D scanning...Stability Program. The test vehicle provides measurements that include three forces and moments at each wheel center, vehicle body slip angle , speed

Laser interferometer skin-friction measurements of crossing-shock-wave/turbulent-boundary-layer interactions

NASA Technical Reports Server (NTRS)

Garrison, T. J.; Settles, G. S.; Narayanswami, N.; Knight, D. D.

1994-01-01

Wall shear stress measurements beneath crossing-shock-wave/turbulent boundary-layer interactions have been made for three interactions of different strengths. The interactions are generated by two sharp fins at symetric angles of attack mounted on a flat plate. The shear stress measurements were made for fin angles of 7 and 11 deg at Mach 3 and 15 deg at Mach 3.85. The measurements were made using a laser interferometer skin-friction meter, a device that determines the wall shear by optically measuring the time rate of thinning of an oil film placed on the test model surface. Results of the measurements reveal high skin-friction coefficients in the vicinity of the fin/plate junction and the presence of quasi-two-dimensional flow separation on the interaction center line. Additionally, two Navier-Stokes computations, one using a Baldwin-Lomax turbulence model and one using a k-epsilon model, are compared with the experimental results for the Mach 3.85, 15-deg interaction case. Although the k-epsilon model did a reasonable job of predicting the overall trend in portions of the skin-friction distribution, neither computation fully captured the physics of the near-surface flow in this complex interaction.

A Hybrid Coarse-graining Approach for Lipid Bilayers at Large Length and Time Scales

PubMed Central

Ayton, Gary S.; Voth, Gregory A.

2009-01-01

A hybrid analytic-systematic (HAS) coarse-grained (CG) lipid model is developed and employed in a large-scale simulation of a liposome. The methodology is termed hybrid analyticsystematic as one component of the interaction between CG sites is variationally determined from the multiscale coarse-graining (MS-CG) methodology, while the remaining component utilizes an analytic potential. The systematic component models the in-plane center of mass interaction of the lipids as determined from an atomistic-level MD simulation of a bilayer. The analytic component is based on the well known Gay-Berne ellipsoid of revolution liquid crystal model, and is designed to model the highly anisotropic interactions at a highly coarse-grained level. The HAS CG approach is the first step in an “aggressive” CG methodology designed to model multi-component biological membranes at very large length and timescales. PMID:19281167

KSC-2014-3130

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones, left, presses the button on a simulated model of an asteroid to mark the grand opening of the new Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. To his right is Therrin Protze, chief operating officer with Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Analytical interatomic potential for modeling nonequilibrium processes in the W-C-H system

NASA Astrophysics Data System (ADS)

Juslin, N.; Erhart, P.; Träskelin, P.; Nord, J.; Henriksson, K. O. E.; Nordlund, K.; Salonen, E.; Albe, K.

2005-12-01

A reactive interatomic potential based on an analytical bond-order scheme is developed for the ternary system W-C-H. The model combines Brenner's hydrocarbon potential with parameter sets for W-W, W-C, and W-H interactions and is adjusted to materials properties of reference structures with different local atomic coordinations including tungsten carbide, W-H molecules, as well as H dissolved in bulk W. The potential has been tested in various scenarios, such as surface, defect, and melting properties, none of which were considered in the fitting. The intended area of application is simulations of hydrogen and hydrocarbon interactions with tungsten, which have a crucial role in fusion reactor plasma-wall interactions. Furthermore, this study shows that the angular-dependent bond-order scheme can be extended to second nearest-neighbor interactions, which are relevant in body-centered-cubic metals. Moreover, it provides a possibly general route for modeling metal carbides.

Continued use of an interactive computer game-based visual perception learning system in children with developmental delay.

PubMed

Lin, Hsien-Cheng; Chiu, Yu-Hsien; Chen, Yenming J; Wuang, Yee-Pay; Chen, Chiu-Ping; Wang, Chih-Chung; Huang, Chien-Ling; Wu, Tang-Meng; Ho, Wen-Hsien

2017-11-01

This study developed an interactive computer game-based visual perception learning system for special education children with developmental delay. To investigate whether perceived interactivity affects continued use of the system, this study developed a theoretical model of the process in which learners decide whether to continue using an interactive computer game-based visual perception learning system. The technology acceptance model, which considers perceived ease of use, perceived usefulness, and perceived playfulness, was extended by integrating perceived interaction (i.e., learner-instructor interaction and learner-system interaction) and then analyzing the effects of these perceptions on satisfaction and continued use. Data were collected from 150 participants (rehabilitation therapists, medical paraprofessionals, and parents of children with developmental delay) recruited from a single medical center in Taiwan. Structural equation modeling and partial-least-squares techniques were used to evaluate relationships within the model. The modeling results indicated that both perceived ease of use and perceived usefulness were positively associated with both learner-instructor interaction and learner-system interaction. However, perceived playfulness only had a positive association with learner-system interaction and not with learner-instructor interaction. Moreover, satisfaction was positively affected by perceived ease of use, perceived usefulness, and perceived playfulness. Thus, satisfaction positively affects continued use of the system. The data obtained by this study can be applied by researchers, designers of computer game-based learning systems, special education workers, and medical professionals. Copyright © 2017 Elsevier B.V. All rights reserved.

KSC-2014-3129

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones welcomes visitors to the grand opening of the Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Effects of air-sea interaction on extended-range prediction of geopotential height at 500 hPa over the northern extratropical region

NASA Astrophysics Data System (ADS)

Wang, Xujia; Zheng, Zhihai; Feng, Guolin

2018-04-01

The contribution of air-sea interaction on the extended-range prediction of geopotential height at 500 hPa in the northern extratropical region has been analyzed with a coupled model form Beijing Climate Center and its atmospheric components. Under the assumption of the perfect model, the extended-range prediction skill was evaluated by anomaly correlation coefficient (ACC), root mean square error (RMSE), and signal-to-noise ratio (SNR). The coupled model has a better prediction skill than its atmospheric model, especially, the air-sea interaction in July made a greater contribution for the improvement of prediction skill than other months. The prediction skill of the extratropical region in the coupled model reaches 16-18 days in all months, while the atmospheric model reaches 10-11 days in January, April, and July and only 7-8 days in October, indicating that the air-sea interaction can extend the prediction skill of the atmospheric model by about 1 week. The errors of both the coupled model and the atmospheric model reach saturation in about 20 days, suggesting that the predictable range is less than 3 weeks.

Recent Naval Postgraduate School Publications.

DTIC Science & Technology

1980-04-01

Numerical models of ocean circulation and Climate interaction Revs, of Geophis,.and Space Phys., vol. 17, no. 7, p. 1494-1507, (1 979) Haney, R 1...POSTGRADUATE SCHOOL Monterey, California DEPARTMENT OF COMPUTER SCIENCE C06FEBENCE PRESENTATIONS Bradley, G H Enerqy modelling with network optimization...Systems Analysis, Sept., 97 Bradley, G H; Brown, G G Network optimization and defense modeling Center for Nay. Analyses, Arlington, Va., Aug., 1976

Science Centres and Science Learning.

ERIC Educational Resources Information Center

Rennie, Leonie J.; McClafferty, Terence P.

1996-01-01

Focuses on the interactive science center and its history over the last four decades. Traces the original idea to Francis Bacon. Recommends the use of cross-site studies to develop a model of learning in this setting. Contains 141 references. (DDR)

Information Architecture for Interactive Archives at the Community Coordianted Modeling Center

NASA Astrophysics Data System (ADS)

De Zeeuw, D.; Wiegand, C.; Kuznetsova, M.; Mullinix, R.; Boblitt, J. M.

2017-12-01

The Community Coordinated Modeling Center (CCMC) is upgrading its meta-data system for model simulations to be compliant with the SPASE meta-data standard. This work is helping to enhance the SPASE standards for simulations to better describe the wide variety of models and their output. It will enable much more sophisticated and automated metrics and validation efforts at the CCMC, as well as much more robust searches for specific types of output. The new meta-data will also allow much more tailored run submissions as it will allow some code options to be selected for Run-On-Request models. We will also demonstrate data accessibility through an implementation of the Heliophysics Application Programmer's Interface (HAPI) protocol of data otherwise available throught the integrated space weather analysis system (iSWA).

Role of phonons in the metal-insulator phase transition.

NASA Technical Reports Server (NTRS)

Langer, W. D.

1972-01-01

Review, for the transition series oxides, of the Mattis and Lander model, which is one of electrons interacting with lattice vibrations (electron and phonon interaction). The model displays superconducting, insulating, and metallic phases. Its basic properties evolve from a finite crystallographic distortion associated with a dominant phonon mode and the splitting of the Brillouin zone into two subzones, a property of simple cubic and body centered cubic lattices. The order of the metal-insulator phase transition is examined. The basic model has a second-order phase transition and the effects of additional mechanisms on the model are calculated. The way in which these mechanisms affect the magnetically ordered transition series oxides as described by the Hubbard model is discussed.

Changing the Rules: Making Space for Interactive Learning in the Galleries of the Detroit Institute of Arts

ERIC Educational Resources Information Center

Czajkowski, Jennifer Wild

2011-01-01

Three years after the Detroit Institute of Arts opened with all new, "visitor-centered" galleries, the museum's executive director of learning and interpretation shares the processes, successes, and lessons learned at an institution that embraced an array of hands-on learning models. The models are discussed as components of a…

Informal science education at Science City

NASA Astrophysics Data System (ADS)

French, April Nicole

The presentation of chemistry within informal learning environments, specifically science museums and science centers is very sparse. This work examines learning in Kansas City's Science City's Astronaut Training Center in order to identify specific behaviors associated with visitors' perception of learning and their attitudes toward space and science to develop an effective chemistry exhibit. Grounded in social-constructivism and the Contextual Model of Learning, this work approaches learning in informal environments as resulting from social interactions constructed over time from interaction between visitors. Visitors to the Astronaut Training Center were surveyed both during their visit and a year after the visit to establish their perceptions of behavior within the exhibit and attitudes toward space and science. Observations of visitor behavior and a survey of the Science City staff were used to corroborate visitor responses. Eighty-six percent of visitors to Science City indicated they had learned from their experiences in the Astronaut Training Center. No correlation was found between this perception of learning and visitor's interactions with exhibit stations. Visitor attitudes were generally positive toward learning in informal settings and space science as it was presented in the exhibit. Visitors also felt positively toward using video game technology as learning tools. This opens opportunities to developing chemistry exhibits using video technology to lessen the waste stream produced by a full scale chemistry exhibit.

The role of self-interacting right-handed neutrinos in galactic structure

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

Argüelles, C.R.; Rueda, J.A.; Ruffini, R.

2016-04-01

It has been shown previously that the DM in galactic halos can be explained by a self-gravitating system of massive keV fermions ('inos') in thermodynamic equilibrium, and predicted the existence of a denser quantum core of inos towards the center of galaxies. In this article we show that the inclusion of self-interactions among the inos, modeled within a relativistic mean-field-theory approach, allows the quantum core to become massive and compact enough to explain the dynamics of the S-cluster stars closest to the Milky Way's galactic center. The application of this model to other galaxies such as large elliptical harboring massivemore » central dark objects of ∼ 10{sup 9} M {sub ⊙} is also investigated. We identify these interacting inos with sterile right-handed neutrinos pertaining to minimal extensions of the Standard Model, and calculate the corresponding total cross-section σ within an electroweak-like formalism to be compared with other observationally inferred cross-section estimates. The coincidence of an ino mass range of few tens of keV derived here only from the galactic structure, with the range obtained independently from other astrophysical and cosmological constraints, points towards an important role of the right-handed neutrinos in the cosmic structure.« less

Final Report for "Tech-X Corporation work for the SciDAC Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM)"

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

Jenkins, Thomas G.; Kruger, Scott E.

Work carried out by Tech-X Corporation for the DoE SciDAC Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM; U.S. DoE Office of Science Award Number DE-FC02-06ER54899) is summarized and is shown to fulfil the project objectives. The Tech-X portion of the SWIM work focused on the development of analytic and computational approaches to study neoclassical tearing modes and their interaction with injected electron cyclotron current drive. Using formalism developed by Hegna, Callen, and Ramos [Phys. Plasmas 16, 112501 (2009); Phys. Plasmas 17, 082502 (2010); Phys. Plasmas 18, 102506 (2011)], analytic approximations for the RF interaction were derived andmore » the numerical methods needed to implement these interactions in the NIMROD extended MHD code were developed. Using the SWIM IPS framework, NIMROD has successfully coupled to GENRAY, an RF ray tracing code; additionally, a numerical control system to trigger the RF injection, adjustment, and shutdown in response to tearing mode activity has been developed. We discuss these accomplishments, as well as prospects for ongoing future research that this work has enabled (which continue in a limited fashion under the SciDAC Center for Extended Magnetohydrodynamic Modeling (CEMM) project and under a baseline theory grant). Associated conference presentations, published articles, and publications in progress are also listed.« less

Using porphyrin-amino acid pairs to model the electrochemistry of heme proteins: experimental and theoretical investigations.

PubMed

Samajdar, Rudra N; Manogaran, Dhivya; Yashonath, S; Bhattacharyya, Aninda J

2018-04-18

Quasi reversibility in electrochemical cycling between different oxidation states of iron is an often seen characteristic of iron containing heme proteins that bind dioxygen. Surprisingly, the system becomes fully reversible in the bare iron-porphyrin complex: hemin. This leads to the speculation that the polypeptide bulk (globin) around the iron-porphyrin active site in these heme proteins is probably responsible for the electrochemical quasi reversibility. To understand the effect of such polypeptide bulk on iron-porphyrin, we study the interaction of specific amino acids with the hemin center in solution. We choose three representative amino acids-histidine (a well-known iron coordinator in bio-inorganic systems), tryptophan (a well-known fluoroprobe for proteins), and cysteine (a redox-active organic molecule). The interactions of these amino acids with hemin are studied using electrochemistry, spectroscopy, and density functional theory. The results indicate that among these three, the interaction of histidine with the iron center is strongest. Further, histidine maintains the electrochemical reversibility of iron. On the other hand, tryptophan and cysteine interact weakly with the iron center but disturb the electrochemical reversibility by contributing their own redox active processes to the system. Put together, this study attempts to understand the molecular interactions that can control electrochemical reversibility in heme proteins. The results obtained here from the three representative amino acids can be scaled up to build a heme-amino acid interaction database that may predict the electrochemical properties of any protein with a defined polypeptide sequence.

Modeling Visual, Vestibular and Oculomotor Interactions in Self-Motion Estimation

NASA Technical Reports Server (NTRS)

Perrone, John

1997-01-01

A computational model of human self-motion perception has been developed in collaboration with Dr. Leland S. Stone at NASA Ames Research Center. The research included in the grant proposal sought to extend the utility of this model so that it could be used for explaining and predicting human performance in a greater variety of aerospace applications. This extension has been achieved along with physiological validation of the basic operation of the model.

Interaction between Faraday rotation and Cotton-Mouton effects in polarimetry modeling for NSTX

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

Zhang, J.; Crocker, N. A.; Carter, T. A.

The evolution of electromagnetic wave polarization is modeled for propagation in the major radial direction in the National Spherical Torus Experiment with retroreflection from the center stack of the vacuum vessel. This modeling illustrates that the Cotton-Mouton effect-elliptization due to the magnetic field perpendicular to the propagation direction-is shown to be strongly weighted to the high-field region of the plasma. An interaction between the Faraday rotation and Cotton-Mouton effects is also clearly identified. Elliptization occurs when the wave polarization direction is neither parallel nor perpendicular to the local transverse magnetic field. Since Faraday rotation modifies the polarization direction during propagation,more » it must also affect the resultant elliptization. The Cotton-Mouton effect also intrinsically results in rotation of the polarization direction, but this effect is less significant in the plasma conditions modeled. The interaction increases at longer wavelength and complicates interpretation of polarimetry measurements.« less

Estimating Interaction Effects With Incomplete Predictor Variables

PubMed Central

Enders, Craig K.; Baraldi, Amanda N.; Cham, Heining

2014-01-01

The existing missing data literature does not provide a clear prescription for estimating interaction effects with missing data, particularly when the interaction involves a pair of continuous variables. In this article, we describe maximum likelihood and multiple imputation procedures for this common analysis problem. We outline 3 latent variable model specifications for interaction analyses with missing data. These models apply procedures from the latent variable interaction literature to analyses with a single indicator per construct (e.g., a regression analysis with scale scores). We also discuss multiple imputation for interaction effects, emphasizing an approach that applies standard imputation procedures to the product of 2 raw score predictors. We thoroughly describe the process of probing interaction effects with maximum likelihood and multiple imputation. For both missing data handling techniques, we outline centering and transformation strategies that researchers can implement in popular software packages, and we use a series of real data analyses to illustrate these methods. Finally, we use computer simulations to evaluate the performance of the proposed techniques. PMID:24707955

Mean centering helps alleviate "micro" but not "macro" multicollinearity.

PubMed

Iacobucci, Dawn; Schneider, Matthew J; Popovich, Deidre L; Bakamitsos, Georgios A

2016-12-01

There seems to be confusion among researchers regarding whether it is good practice to center variables at their means prior to calculating a product term to estimate an interaction in a multiple regression model. Many researchers use mean centered variables because they believe it's the thing to do or because reviewers ask them to, without quite understanding why. Adding to the confusion is the fact that there is also a perspective in the literature that mean centering does not reduce multicollinearity. In this article, we clarify the issues and reconcile the discrepancy. We distinguish between "micro" and "macro" definitions of multicollinearity and show how both sides of such a debate can be correct. To do so, we use proofs, an illustrative dataset, and a Monte Carlo simulation to show the precise effects of mean centering on both individual correlation coefficients as well as overall model indices. We hope to contribute to the literature by clarifying the issues, reconciling the two perspectives, and quelling the current confusion regarding whether and how mean centering can be a useful practice.

Models and applications for space weather forecasting and analysis at the Community Coordinated Modeling Center.

NASA Astrophysics Data System (ADS)

Kuznetsova, Maria

The Community Coordinated Modeling Center (CCMC, http://ccmc.gsfc.nasa.gov) was established at the dawn of the new millennium as a long-term flexible solution to the problem of transition of progress in space environment modeling to operational space weather forecasting. CCMC hosts an expanding collection of state-of-the-art space weather models developed by the international space science community. Over the years the CCMC acquired the unique experience in preparing complex models and model chains for operational environment and developing and maintaining custom displays and powerful web-based systems and tools ready to be used by researchers, space weather service providers and decision makers. In support of space weather needs of NASA users CCMC is developing highly-tailored applications and services that target specific orbits or locations in space and partnering with NASA mission specialists on linking CCMC space environment modeling with impacts on biological and technological systems in space. Confidence assessment of model predictions is an essential element of space environment modeling. CCMC facilitates interaction between model owners and users in defining physical parameters and metrics formats relevant to specific applications and leads community efforts to quantify models ability to simulate and predict space environment events. Interactive on-line model validation systems developed at CCMC make validation a seamless part of model development circle. The talk will showcase innovative solutions for space weather research, validation, anomaly analysis and forecasting and review on-going community-wide model validation initiatives enabled by CCMC applications.

KSC-2014-3135

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Samples of Earth rocks and real meteorites are featured in an interactive display at the new Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Provider communication and role modeling related to patients' perceptions and use of a federally qualified health center-based farmers' market.

PubMed

Friedman, Daniela B; Freedman, Darcy A; Choi, Seul Ki; Anadu, Edith C; Brandt, Heather M; Carvalho, Natalia; Hurley, Thomas G; Young, Vicki M; Hébert, James R

2014-03-01

Farmers' markets have the potential to improve the health of underserved communities, shape people's perceptions, values, and behaviors about healthy eating, and serve as a social space for both community members and vendors. This study explored the influence of health care provider communication and role modeling for diabetic patients within the context of a farmers' market located at a federally qualified health center. Although provider communication about diet decreased over time, communication strategies included: providing patients with "prescriptions" and vouchers for market purchases; educating patients about diet; and modeling healthy purchases. Data from patient interviews and provider surveys revealed that patients enjoyed social aspects of the market including interactions with their health care provider, and providers distributed prescriptions and vouchers to patients, shopped at the market, and believed that the market had potential to improve the health of staff and patients of the federally qualified health center. Provider modeling of healthy behaviors may influence patients' food-related perceptions and dietary behaviors.

Superresolution Microscopy of Single Rare-Earth Emitters in YAG and H 3 Centers in Diamond

NASA Astrophysics Data System (ADS)

Kolesov, R.; Lasse, S.; Rothfuchs, C.; Wieck, A. D.; Xia, K.; Kornher, T.; Wrachtrup, J.

2018-01-01

We demonstrate superresolution imaging of single rare-earth emitting centers, namely, trivalent cerium, in yttrium aluminum garnet crystals by means of stimulated emission depletion (STED) microscopy. The achieved all-optical resolution is ≈50 nm . Similar results were obtained on H 3 color centers in diamond. In both cases, STED resolution is improving slower than the conventional inverse square-root dependence on the depletion beam intensity. In the proposed model of this effect, the anomalous behavior is caused by excited state absorption and the interaction of the emitter with nonfluorescing crystal defects in its local surrounding.

SNIF-ACT: A Cognitive Model of User Navigation on the World Wide Web

DTIC Science & Technology

2007-01-03

opinions of others on a particular topic or problems. Obviously, our model was not able to answer these questions directly, and more research is... Research Center 3333 Coyote Hill Rd Palo Alto, CA 94304, USA Manuscript submitted to Human-Computer Interaction Date: Jan 03, 2007...models. Rational analysis is a variant form of an approach called methodological adaptationism that has also shaped research programs in behavioral

DSMC simulations of shock interactions about sharp double cones

NASA Astrophysics Data System (ADS)

Moss, James N.

2001-08-01

This paper presents the results of a numerical study of shock interactions resulting from Mach 10 flow about sharp double cones. Computations are made by using the direct simulation Monte Carlo (DSMC) method of Bird. The sensitivity and characteristics of the interactions are examined by varying flow conditions, model size, and configuration. The range of conditions investigated includes those for which experiments have been or will be performed in the ONERA R5Ch low-density wind tunnel and the Calspan-University of Buffalo Research Center (CUBRC) Large Energy National Shock (LENS) tunnel.

DSMC Simulations of Shock Interactions About Sharp Double Cones

NASA Technical Reports Server (NTRS)

Moss, James N.

2000-01-01

This paper presents the results of a numerical study of shock interactions resulting from Mach 10 flow about sharp double cones. Computations are made by using the direct simulation Monte Carlo (DSMC) method of Bird. The sensitivity and characteristics of the interactions are examined by varying flow conditions, model size, and configuration. The range of conditions investigated includes those for which experiments have been or will be performed in the ONERA R5Ch low-density wind tunnel and the Calspan-University of Buffalo Research Center (CUBRC) Large Energy National Shock (LENS) tunnel.

Participatory interaction design in user requirements specification in healthcare.

PubMed

Martikainen, Susanna; Ikävalko, Pauliina; Korpela, Mikko

2010-01-01

Healthcare information systems are accused of poor usability even in the popular media in Finland. Doctors especially have been very critical and actively expressed their opinions in public. User involvement and user-centered design methods are seen as the key solution to usability problems. In this paper we describe a research case where participatory methods were experimented within healthcare information systems development in medicinal care in a hospital. The study was part of a larger research project on Activity-driven Information Systems Development in healthcare. The study started by finding out about and modeling the present state of medicinal care in the hospital. After that it was important to define and model the goal state. The goal state, facilitated by the would-be software package, was modeled with the help of user interface drawings as one way of prototyping. Traditional usability methods were extended during the study. According to the health professionals' feedback, the use of participatory and user-centered interaction design methods, particularly user interface drawings enabled them to describe their requirements and create common understanding with the system developers.

[Interprofessional collaboration in the Family Health Strategy: implications for the provision of care and work management].

PubMed

Matuda, Caroline Guinoza; Pinto, Nicanor Rodrigues da Silva; Martins, Cleide Lavieri; Frazão, Paulo

2015-08-01

Interprofessional collaboration is seen as a resource for tackling model of care and workforce problems. The scope of this study was to understand the perception about the shared work and interprofessional collaboration of professionals who work in primary health care. A qualitative study was conducted in São Paulo city. In-depth interviews were performed with professionals from distinct categories who worked in the Family Health Strategy and Support Center for Family Health. The results highlighted the empirical 'professional interaction' and 'production goals' categories. The forms of interaction, the role of specialized matrix support and the perspective in which production goals are perceived by the professionals pointed to tensions between traditional professional logic and collaboration logic. It also revealed the tensions between a model based on specialized procedures and a more collaborative model centered on health needs of families and of the community. The sharing of responsibilities and practices, changes in the logic of patient referral to specialized services and inadequate organizational arrangements remain major challenges to the integration of interprofessional collaboration for the development of new care practices.

Electron paramagnetic resonance g-tensors from state interaction spin-orbit coupling density matrix renormalization group

NASA Astrophysics Data System (ADS)

Sayfutyarova, Elvira R.; Chan, Garnet Kin-Lic

2018-05-01

We present a state interaction spin-orbit coupling method to calculate electron paramagnetic resonance g-tensors from density matrix renormalization group wavefunctions. We apply the technique to compute g-tensors for the TiF3 and CuCl42 - complexes, a [2Fe-2S] model of the active center of ferredoxins, and a Mn4CaO5 model of the S2 state of the oxygen evolving complex. These calculations raise the prospects of determining g-tensors in multireference calculations with a large number of open shells.

Qualitative mechanism models and the rationalization of procedures

NASA Technical Reports Server (NTRS)

Farley, Arthur M.

1989-01-01

A qualitative, cluster-based approach to the representation of hydraulic systems is described and its potential for generating and explaining procedures is demonstrated. Many ideas are formalized and implemented as part of an interactive, computer-based system. The system allows for designing, displaying, and reasoning about hydraulic systems. The interactive system has an interface consisting of three windows: a design/control window, a cluster window, and a diagnosis/plan window. A qualitative mechanism model for the ORS (Orbital Refueling System) is presented to coordinate with ongoing research on this system being conducted at NASA Ames Research Center.

Interaction of the sea breeze with a river breeze in an area of complex coastal heating

NASA Technical Reports Server (NTRS)

Zhong, Shiyuan; Takle, Eugene S.; Leone, John M., Jr.

1991-01-01

The interaction of the sea-breeze circulation with a river-breeze circulation in an area of complex coastal heating (east coast of Florida) was studied using a 3D finite-element mesoscale model. The model simulations are compared with temperature and wind fields observed on a typical fall day during the Kennedy Space Center Atmospheric Boundary Layer Experiment. The results from numerical experiments designed to isolate the effect of the river breeze indicate that the convergence in the sea-breeze front is suppressed when it passes over the cooler surface of the rivers.

Bridging the PSI Knowledge Gap: A Multi-Scale Approach

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

Wirth, Brian D.

2015-01-08

Plasma-surface interactions (PSI) pose an immense scientific hurdle in magnetic confinement fusion and our present understanding of PSI in confinement environments is highly inadequate; indeed, a recent Fusion Energy Sciences Advisory Committee report found that 4 out of the 5 top five fusion knowledge gaps were related to PSI. The time is appropriate to develop a concentrated and synergistic science effort that would expand, exploit and integrate the wealth of laboratory ion-beam and plasma research, as well as exciting new computational tools, towards the goal of bridging the PSI knowledge gap. This effort would broadly advance plasma and material sciences,more » while providing critical knowledge towards progress in fusion PSI. This project involves the development of a Science Center focused on a new approach to PSI science; an approach that both exploits access to state-of-the-art PSI experiments and modeling, as well as confinement devices. The organizing principle is to develop synergistic experimental and modeling tools that treat the truly coupled multi-scale aspect of the PSI issues in confinement devices. This is motivated by the simple observation that while typical lab experiments and models allow independent manipulation of controlling variables, the confinement PSI environment is essentially self-determined with few outside controls. This means that processes that may be treated independently in laboratory experiments, because they involve vastly different physical and time scales, will now affect one another in the confinement environment. Also, lab experiments cannot simultaneously match all exposure conditions found in confinement devices typically forcing a linear extrapolation of lab results. At the same time programmatic limitations prevent confinement experiments alone from answering many key PSI questions. The resolution to this problem is to usefully exploit access to PSI science in lab devices, while retooling our thinking from a linear and de-coupled extrapolation to a multi-scale, coupled approach. The PSI Plasma Center consisted of three equal co-centers; one located at the MIT Plasma Science and Fusion Center, one at UC San Diego Center for Energy Research and one at the UC Berkeley Department of Nuclear Engineering, which moved to the University of Tennessee, Knoxville (UTK) with Professor Brian Wirth in July 2010. The Center had three co-directors: Prof. Dennis Whyte led the MIT co-center, the UCSD co-center was led by Dr. Russell Doerner, and Prof. Brian Wirth led the UCB/UTK center. The directors have extensive experience in PSI and material research, and have been internationally recognized in the magnetic fusion, materials and plasma research fields. The co-centers feature keystone PSI experimental and modeling facilities dedicated to PSI science: the DIONISOS/CLASS facility at MIT, the PISCES facility at UCSD, and the state-of-the-art numerical modeling capabilities at UCB/UTK. A collaborative partner in the center is Sandia National Laboratory at Livermore (SNL/CA), which has extensive capabilities with low energy ion beams and surface diagnostics, as well as supporting plasma facilities, including the Tritium Plasma Experiment, all of which significantly augment the Center. Interpretive, continuum material models are available through SNL/CA, UCSD and MIT. The participating institutions of MIT, UCSD, UCB/UTK, SNL/CA and LLNL brought a formidable array of experimental tools and personnel abilities into the PSI Plasma Center. Our work has focused on modeling activities associated with plasma surface interactions that are involved in effects of He and H plasma bombardment on tungsten surfaces. This involved performing computational material modeling of the surface evolution during plasma bombardment using molecular dynamics modeling. The principal outcomes of the research efforts within the combined experimental – modeling PSI center are to provide a knowledgebase of the mechanisms of surface degradation, and the influence of the surface on plasma conditions.« less

Goddard Cumulus Ensemble (GCE) Model: Application for Understanding Precipitation Processes

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo

2002-01-01

One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with Cloud Resolving Models (CRMs). The CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (size about 2-200 km). The CRMs also allow explicit interaction between out-going longwave (cooling) and incoming solar (heating) radiation with clouds. Observations can provide the initial conditions and validation for CRM results. The Goddard Cumulus Ensemble (GCE) Model, a cloud-resolving model, has been developed and improved at NASA/Goddard Space Flight Center over the past two decades. Dr. Joanne Simpson played a central role in GCE modeling developments and applications. She was the lead author or co-author on more than forty GCE modeling papers. In this paper, a brief discussion and review of the application of the GCE model to (1) cloud interactions and mergers, (2) convective and stratiform interaction, (3) mechanisms of cloud-radiation interaction, (4) latent heating profiles and TRMM, and (5) responses of cloud systems to large-scale processes are provided. Comparisons between the GCE model's results, other cloud-resolving model results and observations are also examined.

Robot Plans and Human Plans: Implications for Models of Communication. Technical Report No. 314.

ERIC Educational Resources Information Center

Bruce, Bertram

People in interaction with others organize their perceptions of a social situation in terms of plans even when the others' plans are poorly formulated. They use their models of others' plans in formulating their own. Much of what occurs in discourse centers on a continual communication about and reformulation of one's own plans and one's own…

Objectively Determining the Educational Potential of Computer and Video-Based Courseware; or, Producing Reliable Evaluations Despite the Dog and Pony Show.

ERIC Educational Resources Information Center

Barrett, Andrew J.; And Others

The Center for Interactive Technology, Applications, and Research at the College of Engineering of the University of South Florida (Tampa) has developed objective and descriptive evaluation models to assist in determining the educational potential of computer and video courseware. The computer-based courseware evaluation model and the video-based…

KSC-2014-3126

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones, left, joins Andrea Farmer, senior public relations manager with Delaware North Parks and Resorts at NASA Kennedy Space Center Visitor Complex in Florida, for the grand opening of the Great Balls of Fire exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3133

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones discusses the characteristics of asteroids and meteors with a young guest during the grand opening of the Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3127

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Therrin Protze, chief operating officer with Delaware North Parks and Resorts at NASA's Kennedy Space Center Visitor Complex in Florida, welcomes guests to the grand opening of the Great Balls of Fire exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3132

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones discusses the characteristics of asteroids and meteors with a young guest during the grand opening of the Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Model-independent analyses of dark-matter particle interactions

DOE PAGES

Anand, Nikhil; Fitzpatrick, A. Liam; Haxton, W. C.

2015-03-24

A model-independent treatment of dark-matter particle elastic scattering has been developed, yielding the most general interaction for WIMP-nucleon low-energy scattering, and the resulting amplitude has been embedded into the nucleus, taking into account the selection rules imposed by parity and time-reversal. One finds that, in contrast to the usual spin-independent/spin-dependent (SI/SD) formulation, the resulting cross section contains six independent nuclear response functions, three of which are associated with possible velocity-dependent interactions. We find that current experiments are four orders of magnitude more sensitive to derivative couplings than is apparent in the standard SI/SD treatment, which necessarily associated such interactions withmore » cross sections proportional to v 2 T ~ 10⁻⁶, where v T is the WIMP velocity relative to the center of mass of the nuclear target.« less

UTOPIAN: user-driven topic modeling based on interactive nonnegative matrix factorization.

PubMed

Choo, Jaegul; Lee, Changhyun; Reddy, Chandan K; Park, Haesun

2013-12-01

Topic modeling has been widely used for analyzing text document collections. Recently, there have been significant advancements in various topic modeling techniques, particularly in the form of probabilistic graphical modeling. State-of-the-art techniques such as Latent Dirichlet Allocation (LDA) have been successfully applied in visual text analytics. However, most of the widely-used methods based on probabilistic modeling have drawbacks in terms of consistency from multiple runs and empirical convergence. Furthermore, due to the complicatedness in the formulation and the algorithm, LDA cannot easily incorporate various types of user feedback. To tackle this problem, we propose a reliable and flexible visual analytics system for topic modeling called UTOPIAN (User-driven Topic modeling based on Interactive Nonnegative Matrix Factorization). Centered around its semi-supervised formulation, UTOPIAN enables users to interact with the topic modeling method and steer the result in a user-driven manner. We demonstrate the capability of UTOPIAN via several usage scenarios with real-world document corpuses such as InfoVis/VAST paper data set and product review data sets.

Interaction dynamics of multiple mobile robots with simple navigation strategies

NASA Technical Reports Server (NTRS)

Wang, P. K. C.

1989-01-01

The global dynamic behavior of multiple interacting autonomous mobile robots with simple navigation strategies is studied. Here, the effective spatial domain of each robot is taken to be a closed ball about its mass center. It is assumed that each robot has a specified cone of visibility such that interaction with other robots takes place only when they enter its visibility cone. Based on a particle model for the robots, various simple homing and collision-avoidance navigation strategies are derived. Then, an analysis of the dynamical behavior of the interacting robots in unbounded spatial domains is made. The article concludes with the results of computer simulations studies of two or more interacting robots.

Effects of the Caregiver Interaction Profile Training on Caregiver-Child Interactions in Dutch Child Care Centers: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Helmerhorst, Katrien O.; Riksen-Walraven, J. Marianne; Fukkink, Ruben G.; Tavecchio, Louis W. C.; Gevers Deynoot-Schaub, Mirjam J. J. M.

2017-01-01

Background: Previous studies underscore the need to improve caregiver-child interactions in early child care centers. Objective: In this study we used a randomized controlled trial to examine whether a 5-week video feedback training can improve six key interactive skills of caregivers in early child care centers: Sensitive responsiveness, respect…

Melting Behavior of a Model Molecular Crystalline GeI4

NASA Astrophysics Data System (ADS)

Fuchizaki, Kazuhiro; Asano, Yuta

2015-06-01

A model molecular crystalline GeI4 was examined using molecular dynamics simulation. The model was constructed in such a way that rigid tetrahedral molecules interact with each other via Lennard-Jones potentials whose centers are located at the vertices of a tetrahedron. Because no other interaction that can "soften" the intermolecular interaction was introduced, the melting curve of the model crystalline material does not exhibit the anomaly that was found for the real substance. However, the current investigation is useful in that it could settle the upper bound of pressure below which the model can predict properties of the molecular liquid. Moreover, singularity-free nature of the melting curve allowed us to analytically treat the melting curve in the light of the Kumari-Dass-Kechin equation. As a result, we could definitely conclude that the well-known Simon equation for the melting curve is merely an approximate expression. The condition for the validity of Simon's equation was identified.

Center for modeling of turbulence and transition: Research briefs, 1993

NASA Technical Reports Server (NTRS)

Liou, William W. (Editor)

1994-01-01

This research brief contains the progress reports of the research staff of the Center for Modeling of Turbulence and Transition (CMOTT) from June 1992 to July 1993. It is also an annual report to the Institute for Computational Mechanics in Propulsion located at Ohio Aerospace Institute and NASA Lewis Research Center. The main objectives of the research activities at CMOTT are to develop, validate, and implement turbulence and transition models for flows of interest in propulsion systems. Currently, our research covers eddy viscosity one- and two-equation models, Reynolds-stress algebraic equation models, Reynolds-stress transport equation models, nonequilibrium multiple-scale models, bypass transition models, joint scalar probability density function models, and Renormalization Group Theory and Direct Interaction Approximation methods. Some numerical simulations (LES and DNS) have also been carried out to support the development of turbulence modeling. Last year was CMOTT's third year in operation. During this period, in addition to the above mentioned research, CMOTT has also hosted the following programs: an eighteen-hour short course on 'Turbulence--Fundamentals and Computational Modeling (Part I)' given by CMOTT at the NASA Lewis Research Center; a productive summer visitor research program that has generated many encouraging results; collaborative programs with industry customers to help improve their turbulent flow calculations for propulsion system designs; a biweekly CMOTT seminar series with speakers from within and without the NASA Lewis Research Center including foreign speakers. In addition, CMOTT members have been actively involved in the national and international turbulence research activities. The current CMOTT roster and organization are listed in Appendix A. Listed in Appendix B are the abstracts of the biweekly CMOTT seminar. Appendix C lists the papers contributed by CMOTT members.

Evaluating Galactic Cosmic Ray Environment Models Using RaD-X Flight Data

NASA Technical Reports Server (NTRS)

Norman, R. B.; Mertens, C. J.; Slaba, T. C.

2016-01-01

Galactic cosmic rays enter Earth's atmosphere after interacting with the geomagnetic field. The primary galactic cosmic rays spectrum is fundamentally changed as it interacts with Earth's atmosphere through nuclear and atomic interactions. At points deeper in the atmosphere, such as at airline altitudes, the radiation environment is a combination of the primary galactic cosmic rays and the secondary particles produced through nuclear interactions. The RaD-X balloon experiment measured the atmospheric radiation environment above 20 km during 2 days in September 2015. These experimental measurements were used to validate and quantify uncertainty in physics-based models used to calculate exposure levels for commercial aviation. In this paper, the Badhwar-O'Neill 2014, the International Organization for Standardization 15390, and the German Aerospace Company galactic cosmic ray environment models are used as input into the same radiation transport code to predict and compare dosimetric quantities to RaD-X measurements. In general, the various model results match the measured tissue equivalent dose well, with results generated by the German Aerospace Center galactic cosmic ray environment model providing the best comparison. For dose equivalent and dose measured in silicon, however, the models were compared less favorably to the measurements.

Determination of the Interaction Position of Gamma Photons in Monolithic Scintillators Using Neural Network Fitting

NASA Astrophysics Data System (ADS)

Conde, P.; Iborra, A.; González, A. J.; Hernández, L.; Bellido, P.; Moliner, L.; Rigla, J. P.; Rodríguez-Álvarez, M. J.; Sánchez, F.; Seimetz, M.; Soriano, A.; Vidal, L. F.; Benlloch, J. M.

2016-02-01

In Positron Emission Tomography (PET) detectors based on monolithic scintillators, the photon interaction position needs to be estimated from the light distribution (LD) on the photodetector pixels. Due to the finite size of the scintillator volume, the symmetry of the LD is truncated everywhere except for the crystal center. This effect produces a poor estimation of the interaction positions towards the edges, an especially critical situation when linear algorithms, such as Center of Gravity (CoG), are used. When all the crystal faces are painted black, except the one in contact with the photodetector, the LD can be assumed to behave as the inverse square law, providing a simple theoretical model. Using this LD model, the interaction coordinates can be determined by means of fitting each event to a theoretical distribution. In that sense, the use of neural networks (NNs) has been shown to be an effective alternative to more traditional fitting techniques as nonlinear least squares (LS). The multilayer perceptron is one type of NN which can model non-linear functions well and can be trained to accurately generalize when presented with new data. In this work we have shown the capability of NNs to approximate the LD and provide the interaction coordinates of γ-photons with two different photodetector setups. One experimental setup was based on analog Silicon Photomultipliers (SiPMs) and a charge division diode network, whereas the second setup was based on digital SiPMs (dSiPMs). In both experiments NNs minimized border effects. Average spatial resolutions of 1.9 ±0.2 mm and 1.7 ±0.2 mm for the entire crystal surface were obtained for the analog and dSiPMs approaches, respectively.

Investigation of structural and mechanical properties of rare-earth bismuthide (RBi, R=Ce & Pr) with the NaCl structure at high pressure

NASA Astrophysics Data System (ADS)

Yaduvanshi, Namrata; Kapoor, Shilpa; Singh, Sadhna

2018-05-01

We have investigated the structural and mechanical properties of Cerium and Praseodymium Bismuthides under pressure by means of a three body interaction potential model which includes long range columbic interaction, three body interactions and short range overlap repulsive interaction operative up to second nearest neighbor. These compounds shows transition from NaCl structure to body-centered tetragonal (BCT) structure (distorted CsCl-type P4/mmm). The elastic constants and their properties are also reported. Our calculated results of phase transitions and volume collapses of these compounds show a good agreement with available theoretical and experimental results.

Risk assessment of flange climb derailment of a rail vehicle

NASA Astrophysics Data System (ADS)

Vlakhova, A. V.

2015-01-01

We study the wheel flange climb onto the railhead, which is one of the most dangerous regimes of motion and can lead to derailment. The tangential components of the wheel-rail interaction forces are described by the creep model with small slips taken into account. We pass to the limit of infinite rigidity of the interacting bodies (zero slip velocities). It is shown that, in the actual service conditions of rail vehicle motion, neglecting the wheel-rail slip is not justified; namely, the limit model is determined by the primary Dirac constraints, i.e., finite relations between coordinates and momenta arising owing to the system Lagrangian degeneration. The obtained nonclassical model allows one to study the efficiency of some railway motion safety criteria and analytically estimate derailment conditions, which depend on the flange shape, the track curvature radius, the height of the vehicle center of mass, the wheel-rail interaction forces, the coefficients of friction of the interacting surfaces, and the external perturbation forces and moments.

Negotiation of territorial boundaries in a songbird

PubMed Central

Ellis, Jesse M.; Cropp, Brett F.; Koltz, John M.

2014-01-01

How do territorial neighbors resolve the location of their boundaries? We addressed this question by testing the predictions of 2 nonexclusive game theoretical models for competitive signaling: the sequential assessment game and the territorial bargaining game. Our study species, the banded wren, is a neotropical nonmigratory songbird living in densely packed territorial neighborhoods. The males possess repertoires of approximately 25 song types that are largely shared between neighbors and sequentially delivered with variable switching rates. Over 3 days, boundary disputes among pairs of neighboring males were synchronously recorded, their perch positions were marked, and their behavioral interactions were noted. For each countersinging interaction between 2 focal males, we quantified approach and retreat order, a variety of song and call patterns, closest approach distance, distance from the territorial center, and female presence. Aggressors produced more rattle-buzz songs during the approaching phase of interactions, whereas defenders overlapped their opponent’s songs. During the close phase of the interaction, both males matched frequently, but the key determinant of which one retreated first was song-type diversity—first retreaters sang with a higher diversity. Retreaters also produced more unshared song types during the interaction, and in the retreating phase of the interaction, they overlapped more. A negative correlation between song-type diversity asymmetry and contest duration suggested sequential assessment of motivational asymmetry. The use of this graded signal, which varied with distance from the center and indicated a male’s motivation to defend a particular position, supported the bargaining model. The bargaining game could be viewed as a series of sequential assessment contests. PMID:25419086

Experimental and numerical study on bubble-sphere interaction near a rigid wall

NASA Astrophysics Data System (ADS)

Li, S.; Zhang, A. M.; Han, R.; Liu, Y. Q.

2017-09-01

This study is concerned with the interaction between a violently oscillating bubble and a movable sphere with comparable size near a rigid wall, which is an essential physical phenomenon in many applications such as cavitation, underwater explosion, ultrasonic cleaning, and biomedical treatment. Experiments are performed in a cubic water tank, and the underwater electric discharge technique (580 V DC) is employed to generate a bubble that is initiated between a rigid wall and a sphere in an axisymmetric configuration. The bubble-sphere interactions are captured using a high-speed camera operating at 52 000 frames/s. A classification of the bubble-sphere interaction is proposed, i.e., "weak," "intermediate," and "strong" interactions, identified with three distinct bubble shapes at the maximum volume moment. In the numerical simulations, the boundary integral method and the auxiliary function method are combined to establish a full coupling model that decouples the mutual dependence between the force and the sphere motion. The main features of bubble dynamics in different experiments are well reproduced by our numerical model. Meanwhile, the pressure and velocity fields are also provided for clarifying the associated mechanisms. The effects of two dimensionless standoff parameters, namely, γs (defined as ds/Rm, where ds is the minimum distance between the initial bubble center and the sphere surface and Rm is the maximum bubble radius) and γw (defined as dw/Rm, where dw is the distance between the initial bubble center and the rigid wall), are also discussed.

Microscopic model with temperature-dependent interactions for the free molecule and for the trigonal phase of benzil

NASA Astrophysics Data System (ADS)

Zieliński, P.; More, M.; Cochon, E.; Lefebvre, J.

1996-03-01

The molecule of benzil (diphenylethanedione, C14H10O2) has been approximated by a system of rigid segments to model the lowest-frequency part of its vibrational spectrum. The interactions of internal degrees of freedom have been described with the use of phenomenological force constants. The structure of the trigonal (P3121) phase has then been modelled by means of a temperature-dependent atom-atom potential based on thermal motions of atoms. The potential gives the correct account of the softening of an E-symmetry, zone-center mode which underlies the phase transition to the low-temperature monoclinic phase (P21). The low-frequency modes at the zone center, supposed until now to be difference overtones, have been shown to result from a coupling between internal and external degrees of freedom. A low-frequency soft mode at the point M of the zone border has been found, which explains the behavior of observed peaks in diffuse x-ray scattering experiments. The values and the temperature evolution of the effective elastic constants calculated within the model are in a very good agreement with the results of ultrasonic and Brillouin scattering data. The model has been shown insufficient in the description of dielectric and piezoelectric properties of benzil.

Utilization of a Multi-Disciplinary Approach to Building Effective Command Centers: Process and Products

DTIC Science & Technology

2005-06-01

cognitive task analysis , organizational information dissemination and interaction, systems engineering, collaboration and communications processes, decision-making processes, and data collection and organization. By blending these diverse disciplines command centers can be designed to support decision-making, cognitive analysis, information technology, and the human factors engineering aspects of Command and Control (C2). This model can then be used as a baseline when dealing with work in areas of business processes, workflow engineering, information management,

Intrinsic operators for the electromagnetic nuclear current

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

J. Adam, Jr.; H. Arenhovel

1996-09-01

The intrinsic electromagnetic nuclear meson exchange charge and current operators arising from a separation of the center-of-mass motion are derived for a one-boson-exchange model for the nuclear interaction with scalar, pseudoscalar and vector meson exchange including leading order relativistic terms. Explicit expressions for the meson exchange operators corresponding to the different meson types are given in detail for a two-nucleon system. These intrinsic operators are to be evaluated between intrinsic wave functions in their center-of-mass frame.

The Stability Of Disk Barred Galaxies Over the Past 7 Billion Years

NASA Astrophysics Data System (ADS)

Tapia, Amauri; Simmons, Brooke

2017-01-01

A recently released model of interacting disk galaxies provides a hypothesis for the origins of off center bars in disks. No systematic search for offset bars in the early universe has yet been undertaken. The Galaxy Zoo project has produced data regarding the large-scale bars of many galaxies. Using this data alongside images collected by the Hubble Space Telescope and other sources, we have examined 5190 galaxies for signatures of off-centered bars. Less than 5 percent of the sample shows clear signs of an offset bar. We describe their overall properties of this sub-sample and compare the properties of galaxies with offset bars to those with centered bars. We assess the feasibility of the proposed model and place these galaxies in the context of the overall evolution of galaxies.

More Precise Estimation of Lower-Level Interaction Effects in Multilevel Models.

PubMed

Loeys, Tom; Josephy, Haeike; Dewitte, Marieke

2018-01-01

In hierarchical data, the effect of a lower-level predictor on a lower-level outcome may often be confounded by an (un)measured upper-level factor. When such confounding is left unaddressed, the effect of the lower-level predictor is estimated with bias. Separating this effect into a within- and between-component removes such bias in a linear random intercept model under a specific set of assumptions for the confounder. When the effect of the lower-level predictor is additionally moderated by another lower-level predictor, an interaction between both lower-level predictors is included into the model. To address unmeasured upper-level confounding, this interaction term ought to be decomposed into a within- and between-component as well. This can be achieved by first multiplying both predictors and centering that product term next, or vice versa. We show that while both approaches, on average, yield the same estimates of the interaction effect in linear models, the former decomposition is much more precise and robust against misspecification of the effects of cross-level and upper-level terms, compared to the latter.

Integrated computer-aided design using minicomputers

NASA Technical Reports Server (NTRS)

Storaasli, O. O.

1980-01-01

Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), a highly interactive software, has been implemented on minicomputers at the NASA Langley Research Center. CAD/CAM software integrates many formerly fragmented programs and procedures into one cohesive system; it also includes finite element modeling and analysis, and has been interfaced via a computer network to a relational data base management system and offline plotting devices on mainframe computers. The CAD/CAM software system requires interactive graphics terminals operating at a minimum of 4800 bits/sec transfer rate to a computer. The system is portable and introduces 'interactive graphics', which permits the creation and modification of models interactively. The CAD/CAM system has already produced designs for a large area space platform, a national transonic facility fan blade, and a laminar flow control wind tunnel model. Besides the design/drafting element analysis capability, CAD/CAM provides options to produce an automatic program tooling code to drive a numerically controlled (N/C) machine. Reductions in time for design, engineering, drawing, finite element modeling, and N/C machining will benefit productivity through reduced costs, fewer errors, and a wider range of configuration.

A shared-world conceptual model for integrating space station life sciences telescience operations

NASA Technical Reports Server (NTRS)

Johnson, Vicki; Bosley, John

1988-01-01

Mental models of the Space Station and its ancillary facilities will be employed by users of the Space Station as they draw upon past experiences, perform tasks, and collectively plan for future activities. The operational environment of the Space Station will incorporate telescience, a new set of operational modes. To investigate properties of the operational environment, distributed users, and the mental models they employ to manipulate resources while conducting telescience, an integrating shared-world conceptual model of Space Station telescience is proposed. The model comprises distributed users and resources (active elements); agents who mediate interactions among these elements on the basis of intelligent processing of shared information; and telescience protocols which structure the interactions of agents as they engage in cooperative, responsive interactions on behalf of users and resources distributed in space and time. Examples from the life sciences are used to instantiate and refine the model's principles. Implications for transaction management and autonomy are discussed. Experiments employing the model are described which the authors intend to conduct using the Space Station Life Sciences Telescience Testbed currently under development at Ames Research Center.

Using Technology to Enhance Teaching of Patient-Centered Interviewing for Early Medical Students.

PubMed

Kaltman, Stacey; Talisman, Nicholas; Pennestri, Susan; Syverson, Eleri; Arthur, Paige; Vovides, Yianna

2018-06-01

Effective strategies for teaching communication skills to health professions students are needed. This article describes the design and evaluation of immersive and interactive video simulations for medical students to practice basic communication skills. Three simulations were developed, focusing on patient-centered interviewing techniques such as using open-ended questions, reflections, and empathic responses while assessing a patient's history of present illness. First-year medical students were randomized to simulation or education-as-usual arms. Students in the simulation arm were given access to three interactive video simulations developed using Articulate Storyline, an e-learning authoring tool, to practice and receive feedback on patient-centered interviewing techniques to prepare for their Observed Structured Clinical Examination (OSCE). Trained raters evaluated videos of two OSCE cases for each participant to assess specific communication skills used during the history of present illness component of the interview. Eighty-seven percent of the students in the simulation arm interacted with at least one simulation during the history of present illness. For both OSCE cases, students in the simulation arm asked significantly more open-ended questions. Students in the simulation arm asked significantly fewer closed-ended questions and offered significantly more empathic responses in one OSCE case. No differences were found for reflections. Students reported that the simulations helped improve their communication skills. The use of interactive video simulations was found to be feasible to incorporate into the curriculum and was appealing to students. In addition, students in the simulation arm displayed more behaviors consistent with the patient-centered interviewing model practiced in the simulations. Continued development and research are warranted.

From the limits of the classical model of sensitometric curves to a realistic model based on the percolation theory for GafChromic EBT films.

PubMed

del Moral, F; Vázquez, J A; Ferrero, J J; Willisch, P; Ramírez, R D; Teijeiro, A; López Medina, A; Andrade, B; Vázquez, J; Salvador, F; Medal, D; Salgado, M; Muñoz, V

2009-09-01

Modern radiotherapy uses complex treatments that necessitate more complex quality assurance procedures. As a continuous medium, GafChromic EBT films offer suitable features for such verification. However, its sensitometric curve is not fully understood in terms of classical theoretical models. In fact, measured optical densities and those predicted by the classical models differ significantly. This difference increases systematically with wider dose ranges. Thus, achieving the accuracy required for intensity-modulated radiotherapy (IMRT) by classical methods is not possible, plecluding their use. As a result, experimental parametrizations, such as polynomial fits, are replacing phenomenological expressions in modern investigations. This article focuses on identifying new theoretical ways to describe sensitometric curves and on evaluating the quality of fit for experimental data based on four proposed models. A whole mathematical formalism starting with a geometrical version of the classical theory is used to develop new expressions for the sensitometric curves. General results from the percolation theory are also used. A flat-bed-scanner-based method was chosen for the film analysis. Different tests were performed, such as consistency of the numeric results for the proposed model and double examination using data from independent researchers. Results show that the percolation-theory-based model provides the best theoretical explanation for the sensitometric behavior of GafChromic films. The different sizes of active centers or monomer crystals of the film are the basis of this model, allowing acquisition of information about the internal structure of the films. Values for the mean size of the active centers were obtained in accordance with technical specifications. In this model, the dynamics of the interaction between the active centers of GafChromic film and radiation is also characterized by means of its interaction cross-section value. The percolation model fulfills the accuracy requirements for quality-control procedures when large ranges of doses are used and offers a physical explanation for the film response.

Modeling local structure using crystal field and spin Hamiltonian parameters: the tetragonal FeK3+-OI2- defect center in KTaO3 crystal

NASA Astrophysics Data System (ADS)

Gnutek, P.; Y Yang, Z.; Rudowicz, C.

2009-11-01

The local structure and the spin Hamiltonian (SH) parameters, including the zero-field-splitting (ZFS) parameters D and (a+2F/3), and the Zeeman g factors g_{\\parallel } and g_{\\perp } , are theoretically investigated for the FeK3+-OI2- center in KTaO3 crystal. The microscopic SH (MSH) parameters are modeled within the framework of the crystal field (CF) theory employing the CF analysis (CFA) package, which also incorporates the MSH modules. Our approach takes into account the spin-orbit interaction as well as the spin-spin and spin-other-orbit interactions omitted in previous studies. The superposition model (SPM) calculations are carried out to provide input CF parameters for the CFA/MSH package. The combined SPM-CFA/MSH approach is used to consider various structural models for the FeK3+-OI2- defect center in KTaO3. This modeling reveals that the off-center displacement of the Fe3+ ions, Δ1(Fe3+), combined with an inward relaxation of the nearest oxygen ligands, Δ2(O2-), and the existence of the interstitial oxygen OI2- give rise to a strong tetragonal crystal field. This finding may explain the large ZFS experimentally observed for the FeK3+-OI2- center in KTaO3. Matching the theoretical MSH predictions with the available structural data as well as electron magnetic resonance (EMR) and optical spectroscopy data enables predicting reasonable ranges of values of Δ1(Fe3+) and Δ2(O2-) as well as the possible location of OI2- ligands around Fe3+ ions in KTaO3. The defect structure model obtained using the SPM-CFA/MSH approach reproduces very well the ranges of the experimental SH parameters D, g_{\\parallel } and g_{\\perp } and importantly yields not only the correct magnitude of D but also the sign, unlike previous studies. More reliable predictions may be achieved when experimental data on (a+2F/3) and/or crystal field energy levels become available. Comparison of our results with those arising from alternative models existing in the literature indicates considerable advantages of our method and presumably higher reliability of our predictions.

Computer modeling with randomized-controlled trial data informs the development of person-centered aged care homes.

PubMed

Chenoweth, Lynn; Vickland, Victor; Stein-Parbury, Jane; Jeon, Yun-Hee; Kenny, Patricia; Brodaty, Henry

2015-10-01

To answer questions on the essential components (services, operations and resources) of a person-centered aged care home (iHome) using computer simulation. iHome was developed with AnyLogic software using extant study data obtained from 60 Australian aged care homes, 900+ clients and 700+ aged care staff. Bayesian analysis of simulated trial data will determine the influence of different iHome characteristics on care service quality and client outcomes. Interim results: A person-centered aged care home (socio-cultural context) and care/lifestyle services (interactional environment) can produce positive outcomes for aged care clients (subjective experiences) in the simulated environment. Further testing will define essential characteristics of a person-centered care home.

Super-massive binary black holes in galaxies. Dynamical models and observed structures in Arp 5, 87, 214, 240, and NGC 4027, 6946

NASA Astrophysics Data System (ADS)

Anosova, Joanna P.

2017-06-01

On 14 Sept, 2015 The LIGO reported the first direct detection of gravitational waves and the first direct observation of a binary black hole. These observations demonstrate the existence of binary black holes in stellar systems predicted by Einstein in his general theory of relativity a century earlier.A lot of violent and complicated phenomena take place on different scales in the Universe. Many of them may be caused by multiple centers of gravitational attraction: planetary rings, accretion discs of various scales, peculiar structures of single galaxies and interacting galaxies. In this work, we show that various features of celestial objects can be understood by assuming the existence of two dominant centers of gravity in stellar systems.We study numerically the dynamical evolution of models with the central super-massive binary black holes and extended shells with numerous low-mass particles inside and around the orbits of binaries. These particles could be star clusters or gas and dust complexes. We consider several tens of thousands of initial conditions for the general three-body problem and compile them. We studied the dynamical evolution of all spherical shells together and separately. Our method permits us to study the individual trajectories of particles, their close double and triple approaches, and inspect the time-depending structures in the models. Multiple runs of the models allow us to classify the numerous strong triple interactions of the binary components with low-mass particles; frequently, the "gravitational slingshot" effect occurs in the center of systems. Such strong interactions of bodies are results in various structures with "dumb-bell" bars, close and open spirals, different types of flows, jets etc. These structures are often very similar the observed structures of galaxies.We found some combinations of the initial conditions and model parameters that produce at some time similar structures as that found in the galaxies Arp 5, 87, 214, 240, and NGC 4027, 6946. Our Figures show results of such comparison and the past and future evolution of our models.

Emergence of Alpha and Gamma Like Rhythms in a Large Scale Simulation of Interacting Neurons

NASA Astrophysics Data System (ADS)

Gaebler, Philipp; Miller, Bruce

2007-10-01

In the normal brain, at first glance the electrical activity appears very random. However, certain frequencies emerge during specific stages of sleep or between quiet wake states. This raises the question of whether current mathematical and computational models of interacting neurons can display similar behavior. A recent model developed by Eugene Izhikevich appears to succeed. However, early dynamical simulations used to detect these patterns were possibly compromised by an over-simplified initial condition and evolution algorithm. Utilizing the same model, but a more robust algorithm, here we present our initial results, showing that these patterns persist under a wide range of initial conditions. We employ spectral analysis of the firing patterns of a system of interacting excitatory and inhibitory neurons to demonstrate a bimodal spectrum centered on two frequencies in the range characteristic of alpha and gamma rhythms in the human brain.

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.

Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions.

PubMed

Yigit, Cemil; Heyda, Jan; Dzubiella, Joachim

2015-08-14

We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

Understanding Student Language: An Unsupervised Dialogue Act Classification Approach

ERIC Educational Resources Information Center

Ezen-Can, Aysu; Boyer, Kristy Elizabeth

2015-01-01

Within the landscape of educational data, textual natural language is an increasingly vast source of learning-centered interactions. In natural language dialogue, student contributions hold important information about knowledge and goals. Automatically modeling the dialogue act of these student utterances is crucial for scaling natural language…

PC-Based Virtual Reality for CAD Model Viewing

ERIC Educational Resources Information Center

Seth, Abhishek; Smith, Shana S.-F.

2004-01-01

Virtual reality (VR), as an emerging visualization technology, has introduced an unprecedented communication method for collaborative design. VR refers to an immersive, interactive, multisensory, viewer-centered, 3D computer-generated environment and the combination of technologies required to build such an environment. This article introduces the…

Promoting Interactions Between Humans and Robots Using Robotic Emotional Behavior.

PubMed

Ficocelli, Maurizio; Terao, Junichi; Nejat, Goldie

2016-12-01

The objective of a socially assistive robot is to create a close and effective interaction with a human user for the purpose of giving assistance. In particular, the social interaction, guidance, and support that a socially assistive robot can provide a person can be very beneficial to patient-centered care. However, there are a number of research issues that need to be addressed in order to design such robots. This paper focuses on developing effective emotion-based assistive behavior for a socially assistive robot intended for natural human-robot interaction (HRI) scenarios with explicit social and assistive task functionalities. In particular, in this paper, a unique emotional behavior module is presented and implemented in a learning-based control architecture for assistive HRI. The module is utilized to determine the appropriate emotions of the robot to display, as motivated by the well-being of the person, during assistive task-driven interactions in order to elicit suitable actions from users to accomplish a given person-centered assistive task. A novel online updating technique is used in order to allow the emotional model to adapt to new people and scenarios. Experiments presented show the effectiveness of utilizing robotic emotional assistive behavior during HRI scenarios.

An Informal Outreach Model for Fostering Diversity and inclusion in the Sciences

NASA Astrophysics Data System (ADS)

Morris, P. A.; Obot, V.

2006-05-01

In the greater Houston area we have developed an effective informal education model that encourages communication between racial and ethnic groups, increases the base knowledge of space science, and promotes family involvement in science education. Space Science Student Ambassadors (SSSA), part of a NASA funded MUCERPI program, is student led and interacts with the community through interactive demonstrations, mini-classes for schools, museums, youth clubs, neighborhood centers and community family events. The events vary in length from one day to three weeks. The predominantly African American and Hispanic student ambassadors are recruited from inner city high schools and minority serving universities. NASA Johnson Space Center scientists are involved in the science education and training of the students. The students receive training in safety, classroom control, time management and team building skills. The lead SSSA contacts potential venues and establishes the event calendar. The students organize the activities for each venue. The SSSA increase their science knowledge. The diversity of the students and their cordial interactions serve as role models for venue participants. The participants can visually see the lack of ethnic or racial boundaries as the ambassadors interact with each other and the audience. Many of our SSSA have stated in evaluations that they have learned more about space science in our program than in their classes. Some of our SSSA are now pursuing graduate degrees in the geosciences. These students, prior to their involvement in our program, would not have pursued graduate degrees or they may have pursued degrees in other fields.

Land-atmosphere interactions over the continental United States

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

Zeng, Xubin

This paper briefly discusses four suggested modifications for land surface modeling in climate models. The impact of the modifications on climate simulations is analyzed with the Biosphere-Atmosphere Transfer Scheme (BATS) land surface model. It is found that the modifications can improve BATS simulations. In particular, the sensitivity of BATS to the prescribed value of physical root fraction which cannot be observed from satellite remote sensing or field experiments is improved. These modifications significantly reduce the excessive summer land surface temperature over the continental United States simulated by the National Center for Atmospheric Research Community Climate Model (CCM2) coupled with BATS.more » A land-atmosphere interaction mechanism involving energy and water cycles is proposed to explain the results. 9 refs., 1 fig.« less

3D web based learning of medical equipment employed in intensive care units.

PubMed

Cetin, Aydın

2012-02-01

In this paper, both synchronous and asynchronous web based learning of 3D medical equipment models used in hospital intensive care unit have been described over the moodle course management system. 3D medical equipment models were designed with 3ds Max 2008, then converted to ASE format and added interactivity displayed with Viewpoint-Enliven. 3D models embedded in a web page in html format with dynamic interactivity-rotating, panning and zooming by dragging a mouse over images-and descriptive information is embedded to 3D model by using xml format. A pilot test course having 15 h was applied to technicians who is responsible for intensive care unit at Medical Devices Repairing and Maintenance Center (TABOM) of Turkish High Specialized Hospital.

Atomically informed nonlocal semi-discrete variational Peierls-Nabarro model for planar core dislocations

PubMed Central

Liu, Guisen; Cheng, Xi; Wang, Jian; Chen, Kaiguo; Shen, Yao

2017-01-01

Prediction of Peierls stress associated with dislocation glide is of fundamental concern in understanding and designing the plasticity and mechanical properties of crystalline materials. Here, we develop a nonlocal semi-discrete variational Peierls-Nabarro (SVPN) model by incorporating the nonlocal atomic interactions into the semi-discrete variational Peierls framework. The nonlocal kernel is simplified by limiting the nonlocal atomic interaction in the nearest neighbor region, and the nonlocal coefficient is directly computed from the dislocation core structure. Our model is capable of accurately predicting the displacement profile, and the Peierls stress, of planar-extended core dislocations in face-centered cubic structures. Our model could be extended to study more complicated planar-extended core dislocations, such as <110> {111} dislocations in Al-based and Ti-based intermetallic compounds. PMID:28252102

Interactive knowledge discovery with the doctor-in-the-loop: a practical example of cerebral aneurysms research.

PubMed

Girardi, Dominic; Küng, Josef; Kleiser, Raimund; Sonnberger, Michael; Csillag, Doris; Trenkler, Johannes; Holzinger, Andreas

2016-09-01

Established process models for knowledge discovery find the domain-expert in a customer-like and supervising role. In the field of biomedical research, it is necessary to move the domain-experts into the center of this process with far-reaching consequences for both their research output and the process itself. In this paper, we revise the established process models for knowledge discovery and propose a new process model for domain-expert-driven interactive knowledge discovery. Furthermore, we present a research infrastructure which is adapted to this new process model and demonstrate how the domain-expert can be deeply integrated even into the highly complex data-mining process and data-exploration tasks. We evaluated this approach in the medical domain for the case of cerebral aneurysms research.

Moderating effects of parental well-being on parenting efficacy outcomes by intervention delivery model of the early risers conduct problems prevention program.

PubMed

Piehler, Timothy F; Lee, Susanne S; Bloomquist, Michael L; August, Gerald J

2014-10-01

Parent-focused preventive interventions for youth conduct problems are efficacious when offered in different models of delivery (e.g., individual in-home, group center-based). However, we know little about the characteristics of parents associated with a positive response to a particular model of delivery. We randomly assigned the parents of an ethnically diverse sample of kindergarten through second grade students (n = 246) displaying elevated levels of aggression to parent-focused program delivery models emphasizing receiving services in a community center largely with groups (Center; n = 121) or receiving services via an individualized in-home strategy (Outreach; n = 125). In both delivery models, parents received parent skills training and goal setting/case management/referrals over an average of 16 months. Structural equation modeling revealed a significant interaction between parental well-being at baseline and intervention delivery model in predicting parenting efficacy at year 2, while controlling for baseline levels of parenting efficacy. Within the Outreach model, parents with lower levels of well-being as reported at baseline appeared to show greater improvements in parenting efficacy than parents with higher levels of well-being. Within the Center model, parental well-being did not predict parenting efficacy outcomes. The strong response of low well-being parents within the Outreach model suggests that this may be the preferred model for these parents. These findings provide support for further investigation into tailoring delivery model of parent-focused preventive interventions using parental well-being in order to improve parenting outcomes.

Moderating Effects of Parental Well-Being on Parenting Efficacy Outcomes by Intervention Delivery Model of the Early Risers Conduct Problems Prevention Program

PubMed Central

Piehler, Timothy F.; Lee, Susanne S.; Bloomquist, Michael L.; August, Gerald J.

2014-01-01

Parent-focused preventive interventions for youth conduct problems are efficacious when offered in different models of delivery (e.g., individual in-home, group center-based). However, we know little about the characteristics of parents associated with a positive response to a particular model of delivery. We randomly assigned the parents of an ethnically diverse sample of kindergarten through second grade students (n = 246) displaying elevated levels of aggression to parent-focused program delivery models emphasizing receiving services in a community center largely with groups (Center; n = 121) or receiving services via an individualized in-home strategy (Outreach; n = 125). In both delivery models, parents received parent skills training and goal setting/case management/referrals over an average of 16 months. Structural equation modeling revealed a significant interaction between parental well-being at baseline and intervention delivery model in predicting parenting efficacy at year two, while controlling for baseline levels of parenting efficacy. Within the Outreach model, parents with lower levels of well-being as reported at baseline appeared to show greater improvements in parenting efficacy than parents with higher levels of well-being. Within the Center model, parental well-being did not predict parenting efficacy outcomes. The strong response of low well-being parents within the Outreach model suggests that this may be the preferred model for these parents. These findings provide support for further investigation into tailoring delivery model of parent-focused preventive interventions using parental well-being in order to improve parenting outcomes. PMID:25037843

Electrohydrodynamic deformation and interaction of a pair of emulsion drops

NASA Technical Reports Server (NTRS)

Baygents, James C.

1994-01-01

The response of a pair of emulsion drops to the imposition of a uniform electric field is examined. The case studied is that of equal-sized drops whose line of centers is parallel to the axis of the applied field. A new boundary integral solution to the governing equations of the leaky dielectric model is developed; the formulation accounts for the electrostatic and hydrodynamic interactions between the drops, as well as their deformations. Numerical calculations show that, after an initial transient during which the drops primarily deform, the pair drift slowly together due to their electrostatic interactions.

Self-assembly of skyrmion-dressed chiral nematic colloids with tangential anchoring.

PubMed

Pandey, M B; Porenta, T; Brewer, J; Burkart, A; Copar, S; Zumer, S; Smalyukh, Ivan I

2014-06-01

We describe dipolar nematic colloids comprising mutually bound solid microspheres, three-dimensional skyrmions, and point defects in a molecular alignment field of chiral nematic liquid crystals. Nonlinear optical imaging and numerical modeling based on minimization of Landau-de Gennes free energy reveal that the particle-induced skyrmions resemble torons and hopfions, while matching surface boundary conditions at the interfaces of liquid crystal and colloidal spheres. Laser tweezers and videomicroscopy reveal that the skyrmion-colloidal hybrids exhibit purely repulsive elastic pair interactions in the case of parallel dipoles and an unexpected reversal of interaction forces from repulsive to attractive as the center-to-center distance decreases for antiparallel dipoles. The ensuing elastic self-assembly gives rise to colloidal chains of antiparallel dipoles with particles entangled by skyrmions.

KSC-2014-3128

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Therrin Protze, chief operating officer with Delaware North Parks and Resorts at NASA's Kennedy Space Center Visitor Complex in Florida, welcomes guests to the grand opening of the Great Balls of Fire exhibit. To his left is former NASA astronaut Tom Jones. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3125

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones, left, joins Andrea Farmer, senior public relations manager, and Therrin Protze, chief operating officer, both with Delaware North Parks and Resorts at NASA's Kennedy Space Center Visitor Complex in Florida, for the grand opening of the Great Balls of Fire exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Freezing behavior as a response to sexual visual stimuli as demonstrated by posturography.

PubMed

Mouras, Harold; Lelard, Thierry; Ahmaidi, Said; Godefroy, Olivier; Krystkowiak, Pierre

2015-01-01

Posturographic changes in motivational conditions remain largely unexplored in the context of embodied cognition. Over the last decade, sexual motivation has been used as a good canonical working model to study motivated social interactions. The objective of this study was to explore posturographic variations in response to visual sexual videos as compared to neutral videos. Our results support demonstration of a freezing-type response in response to sexually explicit stimuli compared to other conditions, as demonstrated by significantly decreased standard deviations for (i) the center of pressure displacement along the mediolateral and anteroposterior axes and (ii) center of pressure's displacement surface. These results support the complexity of the motor correlates of sexual motivation considered to be a canonical functional context to study the motor correlates of motivated social interactions.

Using CONFIG for Simulation of Operation of Water Recovery Subsystems for Advanced Control Software Evaluation

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Flores, Luis; Fleming, Land; Throop, Daiv

2002-01-01

A hybrid discrete/continuous simulation tool, CONFIG, has been developed to support evaluation of the operability life support systems. CON FIG simulates operations scenarios in which flows and pressures change continuously while system reconfigurations occur as discrete events. In simulations, intelligent control software can interact dynamically with hardware system models. CONFIG simulations have been used to evaluate control software and intelligent agents for automating life support systems operations. A CON FIG model of an advanced biological water recovery system has been developed to interact with intelligent control software that is being used in a water system test at NASA Johnson Space Center

Mining for Data

NASA Technical Reports Server (NTRS)

1998-01-01

AbTech Corporation used an F-18 HARV (High Alpha Research Vehicle) simulation developed by NASA to create an interactive computer-based prototype of the MQ (Model Quest) SV (System Validator) tool. Dryden Flight Research Center provided support to develop, test, and rapidly reprogram the validation function. AbTech's ModelQuest Enterprises highly automated and outperforms other modeling techniques to quickly discover meaningful relationships, patterns, and trends in databases. Applications include technical and business professionals in finance, marketing, business, banking, retail, healthcare, and aerospace.

Do Responses to Different Anthropogenic Forcings Add Linearly in Climate Models?

NASA Technical Reports Server (NTRS)

Marvel, Kate; Schmidt, Gavin A.; Shindell, Drew; Bonfils, Celine; LeGrande, Allegra N.; Nazarenko, Larissa; Tsigaridis, Kostas

2015-01-01

Many detection and attribution and pattern scaling studies assume that the global climate response to multiple forcings is additive: that the response over the historical period is statistically indistinguishable from the sum of the responses to individual forcings. Here, we use the NASA Goddard Institute for Space Studies (GISS) and National Center for Atmospheric Research Community Climate System Model (CCSM) simulations from the CMIP5 archive to test this assumption for multi-year trends in global-average, annual-average temperature and precipitation at multiple timescales. We find that responses in models forced by pre-computed aerosol and ozone concentrations are generally additive across forcings; however, we demonstrate that there are significant nonlinearities in precipitation responses to di?erent forcings in a configuration of the GISS model that interactively computes these concentrations from precursor emissions. We attribute these to di?erences in ozone forcing arising from interactions between forcing agents. Our results suggest that attribution to specific forcings may be complicated in a model with fully interactive chemistry and may provide motivation for other modeling groups to conduct further single-forcing experiments.

Do responses to different anthropogenic forcings add linearly in climate models?

DOE PAGES

Marvel, Kate; Schmidt, Gavin A.; Shindell, Drew; ...

2015-10-14

Many detection and attribution and pattern scaling studies assume that the global climate response to multiple forcings is additive: that the response over the historical period is statistically indistinguishable from the sum of the responses to individual forcings. Here, we use the NASA Goddard Institute for Space Studies (GISS) and National Center for Atmospheric Research Community Climate System Model (CCSM4) simulations from the CMIP5 archive to test this assumption for multi-year trends in global-average, annual-average temperature and precipitation at multiple timescales. We find that responses in models forced by pre-computed aerosol and ozone concentrations are generally additive across forcings. However,more » we demonstrate that there are significant nonlinearities in precipitation responses to different forcings in a configuration of the GISS model that interactively computes these concentrations from precursor emissions. We attribute these to differences in ozone forcing arising from interactions between forcing agents. Lastly, our results suggest that attribution to specific forcings may be complicated in a model with fully interactive chemistry and may provide motivation for other modeling groups to conduct further single-forcing experiments.« less

Fluid Structure Interaction Analysis on Sidewall Aneurysm Models

NASA Astrophysics Data System (ADS)

Hao, Qing

2016-11-01

Wall shear stress is considered as an important factor for cerebral aneurysm growth and rupture. The objective of present study is to evaluate wall shear stress in aneurysm sac and neck by a fluid-structure-interaction (FSI) model, which was developed and validated against the particle image velocimetry (PIV) data. In this FSI model, the flow characteristics in a straight tube with different asymmetric aneurysm sizes over a range of Reynolds numbers from 200 to 1600 were investigated. The FSI results agreed well with PIV data. It was found that at steady flow conditions, when Reynolds number above 700, one large recirculating vortex would be formed, occupying the entire aneurysm sac. The center of the vortex is located at region near to the distal neck. A pair of counter rotating vortices would however be formed at Reynolds number below 700. Wall shear stresses reached highest level at the distal neck of the aneurysmal sac. The vortex strength, in general, is stronger at higher Reynolds number. Fluid Structure Interaction Analysis on Sidewall Aneurysm Models.

Investigation of Compressibility Effect for Aeropropulsive Shear Flows

NASA Technical Reports Server (NTRS)

Balasubramanyam, M. S.; Chen, C. P.

2005-01-01

Rocket Based Combined Cycle (RBCC) engines operate within a wide range of Mach numbers and altitudes. Fundamental fluid dynamic mechanisms involve complex choking, mass entrainment, stream mixing and wall interactions. The Propulsion Research Center at the University of Alabama in Huntsville is involved in an on- going experimental and numerical modeling study of non-axisymmetric ejector-based combined cycle propulsion systems. This paper attempts to address the modeling issues related to mixing, shear layer/wall interaction in a supersonic Strutjet/ejector flow field. Reynolds Averaged Navier-Stokes (RANS) solutions incorporating turbulence models are sought and compared to experimental measurements to characterize detailed flow dynamics. The effect of compressibility on fluids mixing and wall interactions were investigated using an existing CFD methodology. The compressibility correction to conventional incompressible two- equation models is found to be necessary for the supersonic mixing aspect of the ejector flows based on 2-D simulation results. 3-D strut-base flows involving flow separations were also investigated.

Accessing external innovation in drug discovery and development.

PubMed

Tufféry, Pierre

2015-06-01

A decline in the productivity of the pharmaceutical industry research and development (R&D) pipeline has highlighted the need to reconsider the classical strategies of drug discovery and development, which are based on internal resources, and to identify new means to improve the drug discovery process. Accepting that the combination of internal and external ideas can improve innovation, ways to access external innovation, that is, opening projects to external contributions, have recently been sought. In this review, the authors look at a number of external innovation opportunities. These include increased interactions with academia via academic centers of excellence/innovation centers, better communication on projects using crowdsourcing or social media and new models centered on external providers such as built-to-buy startups or virtual pharmaceutical companies. The buzz for accessing external innovation relies on the pharmaceutical industry's major challenge to improve R&D productivity, a conjuncture favorable to increase interactions with academia and new business models supporting access to external innovation. So far, access to external innovation has mostly been considered during early stages of drug development, and there is room for enhancement. First outcomes suggest that external innovation should become part of drug development in the long term. However, the balance between internal and external developments in drug discovery can vary largely depending on the company strategies.

Slab edge interaction with a back-arc spreading center: 3D instantaneous mantle flow models of Vanuatu, SW Pacific

NASA Astrophysics Data System (ADS)

McLean, K. A.; Jadamec, M.; Durance-Sie, P. M.; Moresi, L. N.

2011-12-01

The Vanuatu area of the south-west Pacific is a dynamic region of high heat-flow and strain-rate, dominated by ongoing plate boundary processes. At the southern termination of the Vanuatu arc the curved geometry of the New Hebrides trench juxtaposes the slab edge perpendicular to its back-arc spreading center. While existing 3D subduction models have demonstrated the importance of mantle flow around a slab edge, the nature of interaction between back-arc upwelling and circum-slab edge mantle flow is not well understood. We use 3D instantaneous numerical models of a Newtonian mantle rheology to test the effect of the slab edge and back-arc upwelling on the mantle flow vector field beneath southern Vanuatu. These high-resolution models simulate temperature-dependent buoyancy-driven deformation of the lithosphere and mantle for a realistic slab geometry. Model results show a small but significant component of vertical mantle flow velocity associated with the slab edge and back-arc spreading center. We also see strain-rate and dynamic topography commensurate with surface observations. Mantle flow by toroidal-type motion brings hotter mantle material from behind the slab into the mantle wedge, elevating geothermal gradients in the slab edge vicinity. The implications of moderate vertical displacement of this hot mantle material at the slab edge are wide-ranging, and such a tectonic framework might aid interpretation of a number of surface observations. For example, induced decompression partial-melting in the mantle wedge and/or slab, and thermal erosion of the slab may contribute to the diverse magma compositions from this region.

Challenging the Context: Perception, Polity, and Power.

ERIC Educational Resources Information Center

Hartfield, Ronne

1994-01-01

"Contextual areas" employ models, replicas, artwork, art materials, tools, interpretive panels, and interactive computer installations to help visitors explore the historical and cultural context of 6 of 12 works of art at the "Art Inside Out" exhibition in the Kraft General Foods Education Center of the Art Institute of Chicago. (MDH)

Relationship-Centered Counseling: The Integrative Interaction of Relationship and Technique.

ERIC Educational Resources Information Center

Kelly, Eugene W., Jr.

Efforts toward integration and eclecticism in counseling and psychotherapy reflect continuing interest in systematically blending theoretical commonalties and eclectically using a variety of techniques across different schools of therapy in the hope of achieving a constituent working model that pools the strengths of different theories and…

A Model for Integrating Technology and Learning in Public Health Education

ERIC Educational Resources Information Center

Bardzell, Shaowen; Bardzell, Jeffrey; So, Hyo-Jeong; Lee, Junghun

2004-01-01

As computer interfaces emerge as an instructional medium, instructors transitioning from the classroom continue to bear the burden of designing effective instruction. The medium of the computer interface, and the kinds of learning and interactive possibilities it affords, presumably changes the delivery of learner-centered instruction.…

Billy J. Roberts | NREL

Science.gov Websites

technique Wildlife and energy technology interactions Geothermal technology Education M.S., Certificate in . Estimate of the Geothermal Energy Resource in the Major Sedimentary Basins in the United States. Paper the Systems Modeling & Geospatial Data Science Group in the Strategic Energy Analysis Center

Design Considerations for Enhancing Confidence and Participation in Web Based Courses.

ERIC Educational Resources Information Center

Winfield, William; Mealy, Martha; Scheibel, Pamela

The University of Wisconsin Learning Innovations Center's instructional design model for World Wide Web delivered courses incorporates a range of collaborative discussions and interactive experiences for the learner. In addition, these courses capitalize on the multimedia learning environment that the web offers to accommodate many kinds of…

Framework for scalable adsorbate–adsorbate interaction models

DOE PAGES

Hoffmann, Max J.; Medford, Andrew J.; Bligaard, Thomas

2016-06-02

Here, we present a framework for physically motivated models of adsorbate–adsorbate interaction between small molecules on transition and coinage metals based on modifications to the substrate electronic structure due to adsorption. We use this framework to develop one model for transition and one for coinage metal surfaces. The models for transition metals are based on the d-band center position, and the models for coinage metals are based on partial charges. The models require no empirical parameters, only two first-principles calculations per adsorbate as input, and therefore scale linearly with the number of reaction intermediates. By theory to theory comparison withmore » explicit density functional theory calculations over a wide range of adsorbates and surfaces, we show that the root-mean-squared error for differential adsorption energies is less than 0.2 eV for up to 1 ML coverage.« less

Secluded WIMPs, Dark QED with Massive Photons, and the Galactic Center Gamma-Ray Excess

NASA Technical Reports Server (NTRS)

Fortes, E. C. F. S.; Pleitez, V.; Stecker, F. W.

2015-01-01

We discuss a particular secluded WIMP dark matter model consisting of neutral fermions as the dark matter candidate and a Proca-Wentzel (PW) field as a mediator. In the model that we consider here, dark matter WIMPs interact with standard model (SM) particles only through the PW field of approximately MeV-multi-GeV mass particles. The interactions occur via a U(1)' mediator, V'(sub mu), which couples to the SM by kinetic mixing with U(1) hypercharge bosons, B'(sub mu). One important difference between our model and other such models in the literature is the absence of an extra singlet scalar, so that the parameter with dimension of mass M(sup 2, sub V) is not related to a spontaneous symmetry breaking. This QED based model is also renormalizable. The mass scale of the mediator and the absence of the singlet scalar can lead to interesting astrophysical signatures. The dominant annihilation channels are different from those usually considered in previous work. We show that the GeV energy gamma-ray excess in the galactic center region, as derived from Fermi-LAT Gamma-ray Space Telescope data, can be attributed to such secluded dark matter WIMPs, given parameters of the model that are consistent with both the cosmological dark matter density and the upper limits on WIMP spin-independent elastic scattering. Secluded WIMP models are also consistent with suggested upper limits on a DM contribution to the cosmic-ray antiproton flux.

Multi-scale dynamics and relaxation of a tethered membrane in a solvent by Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Pandey, Ras; Anderson, Kelly; Farmer, Barry

2006-03-01

A tethered membrane modeled by a flexible sheet dissipates entropy as it wrinkles and crumples. Nodes of a coarse grained membrane are connected via multiple pathways for dynamical modes to propagate. We consider a sheet with nodes connected by fluctuating bonds on a cubic lattice. The empty lattice sites constitute an effective solvent medium via node-solvent interaction. Each node execute its stochastic motion with the Metropolis algorithm subject to bond fluctuations, excluded volume constraints, and interaction energy. Dynamics and conformation of the sheet are examined at a low and a high temperature with attractive and repulsive node-node interactions for the contrast in an attractive solvent medium. Variations of the mean square displacement of the center node of the sheet and that of its center of mass with the time steps are examined in detail which show different power-law motion from short to long time regimes. Relaxation of the gyration radius and scaling of its asymptotic value with the molecular weight are examined.

Antiferromagnetic character of workplace stress

NASA Astrophysics Data System (ADS)

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

2011-07-01

We study the nature of workplace stress from the aspect of human-human interactions. We investigated the distribution of Center for Epidemiological Studies Depression Scale scores, a measure of the degree of stress, in workplaces. We found that the degree of stress people experience when around other highly stressed people tends to be low, and vice versa. A simulation based on a model describing microlevel human-human interaction reproduced this observed phenomena and revealed that the energy state of a face-to-face communication network correlates with workplace stress macroscopically.

Search for scalar dark matter via pseudoscalar portal interactions in light of the Galactic Center gamma-ray excess

NASA Astrophysics Data System (ADS)

Yang, Kwei-Chou

2018-01-01

In light of the observed Galactic center gamma-ray excess, we investigate a simplified model, for which the scalar dark matter interacts with quarks through a pseudoscalar mediator. The viable regions of the parameter space, that can also account for the relic density and evade the current searches, are identified, if the low-velocity dark matter annihilates through an s -channel off shell mediator mostly into b ¯b , and/or annihilates directly into two hidden on shell mediators, which subsequently decay into the quark pairs. These two kinds of annihilations are s wave. The projected monojet limit set by the high luminosity LHC sensitivity could constrain the favored parameter space, where the mediator's mass is larger than the dark matter mass by a factor of 2. We show that the projected sensitivity of 15-year Fermi-LAT observations of dwarf spheroidal galaxies can provide a stringent constraint on the most parameter space allowed in this model. If the on shell mediator channel contributes to the dark matter annihilation cross sections over 50%, this model with a lighter mediator can be probed in the projected PICO-500L experiment.

Regional Climate Simulations over North America: Interaction of Local Processes with Improved Large-Scale Flow.

NASA Astrophysics Data System (ADS)

Miguez-Macho, Gonzalo; Stenchikov, Georgiy L.; Robock, Alan

2005-04-01

The reasons for biases in regional climate simulations were investigated in an attempt to discern whether they arise from deficiencies in the model parameterizations or are due to dynamical problems. Using the Regional Atmospheric Modeling System (RAMS) forced by the National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis, the detailed climate over North America at 50-km resolution for June 2000 was simulated. First, the RAMS equations were modified to make them applicable to a large region, and its turbulence parameterization was corrected. The initial simulations showed large biases in the location of precipitation patterns and surface air temperatures. By implementing higher-resolution soil data, soil moisture and soil temperature initialization, and corrections to the Kain-Fritch convective scheme, the temperature biases and precipitation amount errors could be removed, but the precipitation location errors remained. The precipitation location biases could only be improved by implementing spectral nudging of the large-scale (wavelength of 2500 km) dynamics in RAMS. This corrected for circulation errors produced by interactions and reflection of the internal domain dynamics with the lateral boundaries where the model was forced by the reanalysis.

A Continuum of Compass Spin Models on the Honeycomb Lattice

DTIC Science & Technology

2016-08-02

andAstronomy, GeorgeMasonUniversity, Fairfax, VA 22030,USA 3 WilczekQuantumCenter, ZhejiangUniversity of Technology, Hangzhou 310023, Peopleʼs...lattice [ 3 ]. Later, two of us, andWu independently, found that the 120◦model can be naturally realized in strongly interacting spinless p-orbital...our phase diagram5. The numerical results of TRG are further confirmed and crosscheckedwith projected entangled pair states ( PEPS ) calculations [25, 26

Spin densities from subsystem density-functional theory: Assessment and application to a photosynthetic reaction center complex model

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

Solovyeva, Alisa; Technical University Braunschweig, Institute for Physical and Theoretical Chemistry, Hans-Sommer-Str. 10, 38106 Braunschweig; Pavanello, Michele

2012-05-21

Subsystem density-functional theory (DFT) is a powerful and efficient alternative to Kohn-Sham DFT for large systems composed of several weakly interacting subunits. Here, we provide a systematic investigation of the spin-density distributions obtained in subsystem DFT calculations for radicals in explicit environments. This includes a small radical in a solvent shell, a {pi}-stacked guanine-thymine radical cation, and a benchmark application to a model for the special pair radical cation, which is a dimer of bacteriochlorophyll pigments, from the photosynthetic reaction center of purple bacteria. We investigate the differences in the spin densities resulting from subsystem DFT and Kohn-Sham DFT calculations.more » In these comparisons, we focus on the problem of overdelocalization of spin densities due to the self-interaction error in DFT. It is demonstrated that subsystem DFT can reduce this problem, while it still allows to describe spin-polarization effects crossing the boundaries of the subsystems. In practical calculations of spin densities for radicals in a given environment, it may thus be a pragmatic alternative to Kohn-Sham DFT calculations. In our calculation on the special pair radical cation, we show that the coordinating histidine residues reduce the spin-density asymmetry between the two halves of this system, while inclusion of a larger binding pocket model increases this asymmetry. The unidirectional energy transfer in photosynthetic reaction centers is related to the asymmetry introduced by the protein environment.« less

A one-to-one telestroke network: the first Italian study of a web-based telemedicine system for thrombolysis delivery and patient monitoring.

PubMed

Nardetto, Lucia; Dario, Claudio; Tonello, Simone; Brunelli, Marta Carla; Lisiero, Manola; Carraro, Maria Grazia; Saccavini, Claudio; Scannapieco, Gianluigi; Giometto, Bruno

2016-05-01

Over 10 years after European approval, thrombolysis is still limited by a restricted time window and non-optimal territorial coverage. Implementation of telestroke can give a growing number of patients access to treatment. We hereby present the first Italian telemedicine study applied to both the acute and the monitoring phase of stroke care. From January 2011 to December 2013, we tested a web-based, drip, and treat interaction model, connecting the cerebrovascular specialist of one hub center to the Emergency Department of a Spoke center. We then compared thrombolysis delivered using the telestroke model with thrombolysis provided at the Hub Stroke Unit at the time when the telemedicine program was activated. Telethrombolysis data were then compared with data from the two main international telestroke projects (TEMPiS and REACH), and other European telestroke studies performed at the time of writing. We collected a total of 131 thrombolysis procedures (25 telethrombolysis and 106 thrombolysis patients at the Stroke Unit). Statistical analysis with the t test yielded no statistically significant differences between the two populations in door-to-scan, door-to-needle (DTN), and onset-to-treatment times (OTT). Our OTT and DTN pathway times were longer than the TEMPiS and REACH studies but comparable with other European telemedicine trials, despite different models of interaction and number of centers. Our study in a northeastern province of Italy confirms the potential of applying telemedicine to a cerebrovascular pathology.

Accounting for treatment by center interaction in sample size determinations and the use of surrogate outcomes in the pessary for the prevention of preterm birth trial: a simulation study.

PubMed

Willan, Andrew R

2016-07-05

The Pessary for the Prevention of Preterm Birth Study (PS3) is an international, multicenter, randomized clinical trial designed to examine the effectiveness of the Arabin pessary in preventing preterm birth in pregnant women with a short cervix. During the design of the study two methodological issues regarding power and sample size were raised. Since treatment in the Standard Arm will vary between centers, it is anticipated that so too will the probability of preterm birth in that arm. This will likely result in a treatment by center interaction, and the issue of how this will affect the sample size requirements was raised. The sample size requirements to examine the effect of the pessary on the baby's clinical outcome was prohibitively high, so the second issue is how best to examine the effect on clinical outcome. The approaches taken to address these issues are presented. Simulation and sensitivity analysis were used to address the sample size issue. The probability of preterm birth in the Standard Arm was assumed to vary between centers following a Beta distribution with a mean of 0.3 and a coefficient of variation of 0.3. To address the second issue a Bayesian decision model is proposed that combines the information regarding the between-treatment difference in the probability of preterm birth from PS3 with the data from the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study that relate preterm birth and perinatal mortality/morbidity. The approach provides a between-treatment comparison with respect to the probability of a bad clinical outcome. The performance of the approach was assessed using simulation and sensitivity analysis. Accounting for a possible treatment by center interaction increased the sample size from 540 to 700 patients per arm for the base case. The sample size requirements increase with the coefficient of variation and decrease with the number of centers. Under the same assumptions used for determining the sample size requirements, the simulated mean probability that pessary reduces the risk of perinatal mortality/morbidity is 0.98. The simulated mean decreased with coefficient of variation and increased with the number of clinical sites. Employing simulation and sensitivity analysis is a useful approach for determining sample size requirements while accounting for the additional uncertainty due to a treatment by center interaction. Using a surrogate outcome in conjunction with a Bayesian decision model is an efficient way to compare important clinical outcomes in a randomized clinical trial in situations where the direct approach requires a prohibitively high sample size.

Interaction location outweighs the competitive advantage of numerical superiority in Cebus capucinus intergroup contests.

PubMed

Crofoot, Margaret C; Gilby, Ian C; Wikelski, Martin C; Kays, Roland W

2008-01-15

Numerical superiority confers a competitive advantage during contests among animal groups, shaping patterns of resource access, and, by extension, fitness. However, relative group size does not always determine the winner of intergroup contests. Smaller, presumably weaker social groups often defeat their larger neighbors, but how and when they are able to do so remains poorly understood. Models of competition between individuals suggest that location may influence contest outcome. However, because of the logistical difficulties of studying intergroup interactions, previous studies have been unable to determine how contest location and group size interact to shape relationships among groups. We address this question by using an automated radio telemetry system to study intergroup interactions among six capuchin monkey (Cebus capucinus) social groups of varying sizes. We find that the odds of winning increase with relative group size; one additional group member increases the odds of winning an interaction by 10%. However, this effect is not uniform across space; with each 100 m that a group moves away from the center of its home range, its odds of winning an interaction decrease by 31%. We demonstrate that contest outcome depends on an interaction between group size and location, such that small groups can defeat much larger groups near the center of their home range. The tendency of resident groups to win contests may help explain how small groups persist in areas with intense intergroup competition.

Vibronic effects in the 1.4-eV optical center in diamond

NASA Astrophysics Data System (ADS)

Iakoubovskii, Konstantin; Davies, Gordon

2004-12-01

We report optical absorption and luminescence measurements on the 1.4-eV center in diamond. We show that the zero-phonon lines have a temperature-dependent Ni-isotope shift, that the isotopic shifts induced by carbon and nickel are opposite in sign, and that a local vibronic mode is present in the absorption spectrum but not in luminescence. The microscopic properties of the center are successfully analyzed with the Ludwig-Woodbury theory (LWT), revealing that the Ni+ ion in the 1.4-eV center only weakly interacts with the diamond lattice. The importance of vibronic effects in the LWT analysis is experimentally demonstrated. It is believed that similar effects can account for the discrepancies previously encountered in modeling other 3d9 impurities in semiconductors.

Current and Future Perspectives of Aerosol Research at NASA Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Matsui, Toshihisa; Ichoku, Charles; Randles, Cynthia; Yuan, Tianle; Da Silva, Arlindo M.; Colarco, Peter R.; Kim, Dongchul; Levy, Robert; Sayer, Andrew; Chin, Mian;

The Impacts of Aerosols on Hurricane Katrina under the Effect of Air-Sea Coupling

NASA Astrophysics Data System (ADS)

Lin, Y.; Hsieh, J. S.; Wang, Y.; Zhang, R.

2017-12-01

Aerosols can affect the development of tropical cyclones, which often involve intense interactions with the ocean. Therefore, the impacts of aerosols on the tropical cyclones are reckoned closely associated with the effect of ocean feedback, a priori, which has often been omitted by most of the previous modeling studies about the aerosol effects on tropical cyclones. We investigate the synergetic effects of aerosols and ocean feedback on the development of hurricane Katrina using a convection-resolving coupled regional model (WRF-ROMS). In comparison with observations, our coupled simulation under pristine aerosol condition well captures the pressure drop near the center of Katrina with maximum mean sea level pressure in good agreement with the observation albeit the simulated maximal wind speed is relatively weaker than the observation. Preliminary results suggest that the ocean feedback tends to work with (against) aerosols to suppress (enhance) the hurricane's center pressure drop/maximum wind intensity at the developing (decaying) stage, suggesting a positive (negative) feedback to the aerosols' suppression effect on hurricanes. Moreover, the size of the simulated hurricane considerably expands due to the elevated polluted aerosols while the expansion is weakened, along with the increased precipitation, by the effect of air-sea interactions during the developing stage, which demonstrates intricate nonlinear interactions between aerosols, the hurricane and the ocean.

Hurricane Forecasting with the High-resolution NASA Finite-volume General Circulation Model

NASA Technical Reports Server (NTRS)

Atlas, R.; Reale, O.; Shen, B.-W.; Lin, S.-J.; Chern, J.-D.; Putman, W.; Lee, T.; Yeh, K.-S.; Bosilovich, M.; Radakovich, J.

2004-01-01

A high-resolution finite-volume General Circulation Model (fvGCM), resulting from a development effort of more than ten years, is now being run operationally at the NASA Goddard Space Flight Center and Ames Research Center. The model is based on a finite-volume dynamical core with terrain-following Lagrangian control-volume discretization and performs efficiently on massive parallel architectures. The computational efficiency allows simulations at a resolution of a quarter of a degree, which is double the resolution currently adopted by most global models in operational weather centers. Such fine global resolution brings us closer to overcoming a fundamental barrier in global atmospheric modeling for both weather and climate, because tropical cyclones and even tropical convective clusters can be more realistically represented. In this work, preliminary results of the fvGCM are shown. Fifteen simulations of four Atlantic tropical cyclones in 2002 and 2004 are chosen because of strong and varied difficulties presented to numerical weather forecasting. It is shown that the fvGCM, run at the resolution of a quarter of a degree, can produce very good forecasts of these tropical systems, adequately resolving problems like erratic track, abrupt recurvature, intense extratropical transition, multiple landfall and reintensification, and interaction among vortices.

An Interactive Activation Model of the Effect of Context in Perception. Part 2

DTIC Science & Technology

1980-07-15

nonword strings are often seen with letters transposed if the transposition will produce legal strings (Estes, 1975a; c.f. experiment by Stevens reported...Activation Model Rumelhart & McClelland Part II 90 References Anderson, J. A. Neural models with cognitive implications. In D. LaBerge & S. J. Samuels...Washington, DC 20372 Coe391 Dr. Gory PoockNavy Personnel R&D Center Operations Research Department LT Steven D. Harris. MSC, USN San Diego, CA 92152 Code

Modeling Protein Expression and Protein Signaling Pathways

PubMed Central

Telesca, Donatello; Müller, Peter; Kornblau, Steven M.; Suchard, Marc A.; Ji, Yuan

2015-01-01

High-throughput functional proteomic technologies provide a way to quantify the expression of proteins of interest. Statistical inference centers on identifying the activation state of proteins and their patterns of molecular interaction formalized as dependence structure. Inference on dependence structure is particularly important when proteins are selected because they are part of a common molecular pathway. In that case, inference on dependence structure reveals properties of the underlying pathway. We propose a probability model that represents molecular interactions at the level of hidden binary latent variables that can be interpreted as indicators for active versus inactive states of the proteins. The proposed approach exploits available expert knowledge about the target pathway to define an informative prior on the hidden conditional dependence structure. An important feature of this prior is that it provides an instrument to explicitly anchor the model space to a set of interactions of interest, favoring a local search approach to model determination. We apply our model to reverse-phase protein array data from a study on acute myeloid leukemia. Our inference identifies relevant subpathways in relation to the unfolding of the biological process under study. PMID:26246646

Using the Gravity Model to Estimate the Spatial Spread of Vector-Borne Diseases

PubMed Central

Barrios, José Miguel; Verstraeten, Willem W.; Maes, Piet; Aerts, Jean-Marie; Farifteh, Jamshid; Coppin, Pol

2012-01-01

The gravity models are commonly used spatial interaction models. They have been widely applied in a large set of domains dealing with interactions amongst spatial entities. The spread of vector-borne diseases is also related to the intensity of interaction between spatial entities, namely, the physical habitat of pathogens’ vectors and/or hosts, and urban areas, thus humans. This study implements the concept behind gravity models in the spatial spread of two vector-borne diseases, nephropathia epidemica and Lyme borreliosis, based on current knowledge on the transmission mechanism of these diseases. Two sources of information on vegetated systems were tested: the CORINE land cover map and MODIS NDVI. The size of vegetated areas near urban centers and a local indicator of occupation-related exposure were found significant predictors of disease risk. Both the land cover map and the space-borne dataset were suited yet not equivalent input sources to locate and measure vegetated areas of importance for disease spread. The overall results point at the compatibility of the gravity model concept and the spatial spread of vector-borne diseases. PMID:23202882

Using the gravity model to estimate the spatial spread of vector-borne diseases.

PubMed

Barrios, José Miguel; Verstraeten, Willem W; Maes, Piet; Aerts, Jean-Marie; Farifteh, Jamshid; Coppin, Pol

2012-11-30

The gravity models are commonly used spatial interaction models. They have been widely applied in a large set of domains dealing with interactions amongst spatial entities. The spread of vector-borne diseases is also related to the intensity of interaction between spatial entities, namely, the physical habitat of pathogens’ vectors and/or hosts, and urban areas, thus humans. This study implements the concept behind gravity models in the spatial spread of two vector-borne diseases, nephropathia epidemica and Lyme borreliosis, based on current knowledge on the transmission mechanism of these diseases. Two sources of information on vegetated systems were tested: the CORINE land cover map and MODIS NDVI. The size of vegetated areas near urban centers and a local indicator of occupation-related exposure were found significant predictors of disease risk. Both the land cover map and the space-borne dataset were suited yet not equivalent input sources to locate and measure vegetated areas of importance for disease spread. The overall results point at the compatibility of the gravity model concept and the spatial spread of vector-borne diseases.

Anion-π interactions in active centers of superoxide dismutases.

PubMed

Ribić, Vesna R; Stojanović, Srđan Đ; Zlatović, Mario V

2018-01-01

We investigated 1060 possible anion-π interactions in a data set of 41 superoxide dismutase active centers. Our observations indicate that majority of the aromatic residues are capable to form anion-π interactions, mainly by long-range contacts, and that there is preference of Trp over other aromatic residues in these interactions. Furthermore, 68% of total predicted interactions in the dataset are multiple anion-π interactions. Anion-π interactions are distance and orientation dependent. We analyzed the energy contribution resulting from anion-π interactions using ab initio calculations. The results showed that, while most of their interaction energies lay in the range from -0 to -4kcalmol -1 , those energies can be up to -9kcalmol -1 and about 34% of interactions were found to be repulsive. Majority of the suggested anion-π interacting residues in ternary complexes are metal-assisted. Stabilization centers for these proteins showed that all the six residues found in predicted anion-π interactions are important in locating one or more of such centers. The anion-π interacting residues in these proteins were found to be highly conserved. We hope that these studies might contribute useful information regarding structural stability and its interaction in future designs of novel metalloproteins. Copyright © 2017 Elsevier B.V. All rights reserved.

Statistical modeling for visualization evaluation through data fusion.

PubMed

Chen, Xiaoyu; Jin, Ran

2017-11-01

There is a high demand of data visualization providing insights to users in various applications. However, a consistent, online visualization evaluation method to quantify mental workload or user preference is lacking, which leads to an inefficient visualization and user interface design process. Recently, the advancement of interactive and sensing technologies makes the electroencephalogram (EEG) signals, eye movements as well as visualization logs available in user-centered evaluation. This paper proposes a data fusion model and the application procedure for quantitative and online visualization evaluation. 15 participants joined the study based on three different visualization designs. The results provide a regularized regression model which can accurately predict the user's evaluation of task complexity, and indicate the significance of all three types of sensing data sets for visualization evaluation. This model can be widely applied to data visualization evaluation, and other user-centered designs evaluation and data analysis in human factors and ergonomics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Service of Remembrance: a comprehensive cancer center's response to bereaved family members.

PubMed

Knight, Louise; Cooper, Rhonda S; Hypki, Cinder

2012-01-01

Comprehensive cancer centers that offer an array of clinical trials and treatment options often experience significant patient mortality rates. Bereavement resources may not be routinely incorporated into the service delivery model in these specialty hospitals. In response, an interdisciplinary team at one cancer center proposed, planned, and implemented an annual Service of Remembrance. The incorporation of music, poetry, and visual arts was important in designing a program that would provide a meaningful, spiritual experience. A community artist who designed an interactive memorial art piece played a pivotal role. This article outlines the process of institutional culture change and describes future challenges in the implementation of this type of bereavement service.

Social Interaction and Design in an Online Multiliteracy Center

ERIC Educational Resources Information Center

Beaver, Alaina Feltenberger

2016-01-01

This qualitative study investigates tutor and student interaction in an online multiliteracy center (the Hub) at a major public research university. This study addresses a gap in the current literature on how writing centers transition to multiliteracy centers and prepare their tutors for consulting with students around aspects of design. There is…

Hypothesis generation using network structures on community health center cancer-screening performance.

PubMed

Carney, Timothy Jay; Morgan, Geoffrey P; Jones, Josette; McDaniel, Anna M; Weaver, Michael T; Weiner, Bryan; Haggstrom, David A

2015-10-01

Nationally sponsored cancer-care quality-improvement efforts have been deployed in community health centers to increase breast, cervical, and colorectal cancer-screening rates among vulnerable populations. Despite several immediate and short-term gains, screening rates remain below national benchmark objectives. Overall improvement has been both difficult to sustain over time in some organizational settings and/or challenging to diffuse to other settings as repeatable best practices. Reasons for this include facility-level changes, which typically occur in dynamic organizational environments that are complex, adaptive, and unpredictable. This study seeks to understand the factors that shape community health center facility-level cancer-screening performance over time. This study applies a computational-modeling approach, combining principles of health-services research, health informatics, network theory, and systems science. To investigate the roles of knowledge acquisition, retention, and sharing within the setting of the community health center and to examine their effects on the relationship between clinical decision support capabilities and improvement in cancer-screening rate improvement, we employed Construct-TM to create simulated community health centers using previously collected point-in-time survey data. Construct-TM is a multi-agent model of network evolution. Because social, knowledge, and belief networks co-evolve, groups and organizations are treated as complex systems to capture the variability of human and organizational factors. In Construct-TM, individuals and groups interact by communicating, learning, and making decisions in a continuous cycle. Data from the survey was used to differentiate high-performing simulated community health centers from low-performing ones based on computer-based decision support usage and self-reported cancer-screening improvement. This virtual experiment revealed that patterns of overall network symmetry, agent cohesion, and connectedness varied by community health center performance level. Visual assessment of both the agent-to-agent knowledge sharing network and agent-to-resource knowledge use network diagrams demonstrated that community health centers labeled as high performers typically showed higher levels of collaboration and cohesiveness among agent classes, faster knowledge-absorption rates, and fewer agents that were unconnected to key knowledge resources. Conclusions and research implications: Using the point-in-time survey data outlining community health center cancer-screening practices, our computational model successfully distinguished between high and low performers. Results indicated that high-performance environments displayed distinctive network characteristics in patterns of interaction among agents, as well as in the access and utilization of key knowledge resources. Our study demonstrated how non-network-specific data obtained from a point-in-time survey can be employed to forecast community health center performance over time, thereby enhancing the sustainability of long-term strategic-improvement efforts. Our results revealed a strategic profile for community health center cancer-screening improvement via simulation over a projected 10-year period. The use of computational modeling allows additional inferential knowledge to be drawn from existing data when examining organizational performance in increasingly complex environments. Copyright © 2015 Elsevier Inc. All rights reserved.

EEGLAB, SIFT, NFT, BCILAB, and ERICA: new tools for advanced EEG processing.

PubMed

Delorme, Arnaud; Mullen, Tim; Kothe, Christian; Akalin Acar, Zeynep; Bigdely-Shamlo, Nima; Vankov, Andrey; Makeig, Scott

2011-01-01

We describe a set of complementary EEG data collection and processing tools recently developed at the Swartz Center for Computational Neuroscience (SCCN) that connect to and extend the EEGLAB software environment, a freely available and readily extensible processing environment running under Matlab. The new tools include (1) a new and flexible EEGLAB STUDY design facility for framing and performing statistical analyses on data from multiple subjects; (2) a neuroelectromagnetic forward head modeling toolbox (NFT) for building realistic electrical head models from available data; (3) a source information flow toolbox (SIFT) for modeling ongoing or event-related effective connectivity between cortical areas; (4) a BCILAB toolbox for building online brain-computer interface (BCI) models from available data, and (5) an experimental real-time interactive control and analysis (ERICA) environment for real-time production and coordination of interactive, multimodal experiments.

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).

PSI-Center Simulations of Validation Platform Experiments

NASA Astrophysics Data System (ADS)

Nelson, B. A.; Akcay, C.; Glasser, A. H.; Hansen, C. J.; Jarboe, T. R.; Marklin, G. J.; Milroy, R. D.; Morgan, K. D.; Norgaard, P. C.; Shumlak, U.; Victor, B. S.; Sovinec, C. R.; O'Bryan, J. B.; Held, E. D.; Ji, J.-Y.; Lukin, V. S.

2013-10-01

The Plasma Science and Innovation Center (PSI-Center - http://www.psicenter.org) supports collaborating validation platform experiments with extended MHD simulations. Collaborators include the Bellan Plasma Group (Caltech), CTH (Auburn U), FRX-L (Los Alamos National Laboratory), HIT-SI (U Wash - UW), LTX (PPPL), MAST (Culham), Pegasus (U Wisc-Madison), PHD/ELF (UW/MSNW), SSX (Swarthmore College), TCSU (UW), and ZaP/ZaP-HD (UW). Modifications have been made to the NIMROD, HiFi, and PSI-Tet codes to specifically model these experiments, including mesh generation/refinement, non-local closures, appropriate boundary conditions (external fields, insulating BCs, etc.), and kinetic and neutral particle interactions. The PSI-Center is exploring application of validation metrics between experimental data and simulations results. Biorthogonal decomposition is proving to be a powerful method to compare global temporal and spatial structures for validation. Results from these simulation and validation studies, as well as an overview of the PSI-Center status will be presented.

Freezing Behavior as a Response to Sexual Visual Stimuli as Demonstrated by Posturography

PubMed Central

Mouras, Harold; Lelard, Thierry; Ahmaidi, Said; Godefroy, Olivier; Krystkowiak, Pierre

2015-01-01

Posturographic changes in motivational conditions remain largely unexplored in the context of embodied cognition. Over the last decade, sexual motivation has been used as a good canonical working model to study motivated social interactions. The objective of this study was to explore posturographic variations in response to visual sexual videos as compared to neutral videos. Our results support demonstration of a freezing-type response in response to sexually explicit stimuli compared to other conditions, as demonstrated by significantly decreased standard deviations for (i) the center of pressure displacement along the mediolateral and anteroposterior axes and (ii) center of pressure’s displacement surface. These results support the complexity of the motor correlates of sexual motivation considered to be a canonical functional context to study the motor correlates of motivated social interactions. PMID:25992571

KSC-2014-3131

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Lights flickered and balloons fell as former NASA astronaut Tom Jones, left, and Therrin Protze, chief operating officer of Delaware North Parks and Resorts at NASA’s Kennedy Space Center Visitor Complex in Florida, welcomed guests to the grand opening of the Great Balls of Fire exhibit at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3136

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – The grand opening of the new Great Balls of Fire exhibit was held at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3134

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – A real asteroid is on display at the new Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening of the new attraction featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Development of Monopole Interaction Models for Ionic Compounds. Part I: Estimation of Aqueous Henry's Law Constants for Ions and Gas Phase pKa Values for Acidic Compounds.

PubMed

Hilal, S H; Saravanaraj, A N; Carreira, L A

2014-02-01

The SPARC (SPARC Performs Automated Reasoning in Chemistry) physicochemical mechanistic models for neutral compounds have been extended to estimate Henry's Law Constant (HLC) for charged species by incorporating ionic electrostatic interaction models. Combinations of absolute aqueous pKa values, relative pKa values in the gas phase, and aqueous HLC for neutral compounds have been used to develop monopole interaction models that quantify the energy differences upon moving an ionic solute molecule from the gas phase to the liquid phase. Inter-molecular interaction energies were factored into mechanistic contributions of monopoles with polarizability, dipole, H-bonding, and resonance. The monopole ionic models were validated by a wide range of measured gas phase pKa data for 450 acidic compounds. The RMS deviation error and R(2) for the OH, SH, CO2 H, CH3 and NR2 acidic reaction centers (C) were 16.9 kcal/mol and 0.87, respectively. The calculated HLCs of ions were compared to the HLCs of 142 ions calculated by quantum mechanics. Effects of inter-molecular interaction of the monopoles with polarizability, dipole, H-bonding, and resonance on acidity of the solutes in the gas phase are discussed. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interactive modeling-synthesis-characterization approach towards controllable in situ self-assembly of artificial pinning centers in RE-123 films

NASA Astrophysics Data System (ADS)

Wu, Judy; Shi, Jack

2017-10-01

Raising critical current density J c in high temperature superconductors (HTSs) is an important strategy towards performance-cost balanced HTS technology for commercialization. The development of strong nanoscale artificial pinning centers (APCs) in HTS, such as YBa2Cu3O7 or RE-123 in general, represents one of the most exciting progressions in HTS material research in the last decade. Significantly raised J c has been demonstrated in APC/RE-123 nanocomposites by enhanced pinning on magnetic vortices in magnetic fields towards that demanded in practical applications. Among other processes, strain-mediated self-organization has been explored extensively for in situ formation of the APCs based on fundamental physics design rules. The desire in controlling the morphology, dimension, orientation, and concentration of APCs has led to a fundamental question on how strains interact in determining APCs at a macroscopic scale. Answering this question demands an interactive modeling-synthesis-characterization approach towards a thorough understanding of fundamental physics governing the strain-mediated self-organization of the APCs in the APC/RE-123 nanocomposites. Such an understanding is the key for a leap forward from the traditionally empirical method to materials-by-design to enable an optimal APC landscape to be achieved in epitaxial films of APC/YBCO nanocomposites under a precise guidance of fundamental physics. The paper intends to provide a review of recent progress made in the controllable generation of APCs using the interactive modeling-synthesis-characterization approach. The emphasis will be given to the understanding so far achieved using such an approach on the collective effect of the strain field on the morphology, dimension, and orientation of APCs in epitaxial APC/RE-123 nanocomposite films.

Research activities at the Center for Modeling of Turbulence and Transition

NASA Technical Reports Server (NTRS)

Shih, Tsan-Hsing

1993-01-01

The main research activities at the Center for Modeling of Turbulence and Transition (CMOTT) are described. The research objective of CMOTT is to improve and/or develop turbulence and transition models for propulsion systems. The flows of interest in propulsion systems can be both compressible and incompressible, three dimensional, bounded by complex wall geometries, chemically reacting, and involve 'bypass' transition. The most relevant turbulence and transition models for the above flows are one- and two-equation eddy viscosity models, Reynolds stress algebraic- and transport-equation models, pdf models, and multiple-scale models. All these models are classified as one-point closure schemes since only one-point (in time and space) turbulent correlations, such as second moments (Reynolds stresses and turbulent heat fluxes) and third moments, are involved. In computational fluid dynamics, all turbulent quantities are one-point correlations. Therefore, the study of one-point turbulent closure schemes is the focus of our turbulence research. However, other research, such as the renormalization group theory, the direct interaction approximation method, and numerical simulations are also pursued to support the development of turbulence modeling.

The Electric Propulsion Interactions Code (EPIC)

NASA Technical Reports Server (NTRS)

Mikellides, I. G.; Mandell, M. J.; Kuharski, R. A.; Davis, V. A.; Gardner, B. M.; Minor, J.

2004-01-01

Science Applications International Corporation is currently developing the Electric Propulsion Interactions Code, EPIC, as part of a project sponsored by the Space Environments and Effects Program at the NASA Marshall Space Flight Center. Now in its second year of development, EPIC is an interactive computer tool that allows the construction of a 3-D spacecraft model, and the assessment of a variety of interactions between its subsystems and the plume from an electric thruster. These interactions may include erosion of surfaces due to sputtering and re-deposition of sputtered materials, surface heating, torque on the spacecraft, and changes in surface properties due to erosion and deposition. This paper describes the overall capability of EPIC and provides an outline of the physics and algorithms that comprise many of its computational modules.

MyTeachingPartner: A Professional Development Intervention for Teacher Self-Efficacy

ERIC Educational Resources Information Center

Jamil, Faiza M.

2012-01-01

MyTeachingPartner (MTP) is an interactive, web-based professional development format created at the Center for Advanced Studies in Teaching and Learning (CASTL) at the University of Virginia (Hadden & Pianta, 2006). The MTP model is based on the understanding that effective teacher professional development requires opportunities for teachers…

Descriptive and Evaluative Language in Group Tutorials.

ERIC Educational Resources Information Center

Gilewicz, Magdalena; Thonus, Terese

One advantage of writing center tutorial groups over individual tutoring is that in groups students have the opportunity to become readers of others' writing and to provide feedback to their peers. In such groups, it is assumed that the tutor as facilitator serves as an interactional and linguistic model for students. To test this hypothesis, over…

Getting Students to Learn about Information Systems Project Management: An Experiment in Student-centred Learning.

ERIC Educational Resources Information Center

Allan, George

1999-01-01

A student-centered learning model for a course on information systems project management consisted of individual study and group discussion with facilitator guidance. Data from session records, repertory grids, and a learning network diagram showed that interactive learning was more effective and students took responsibility, although some…

Classroom Learning and Achievement: How the Complexity of Classroom Interaction Impacts Students' Learning

ERIC Educational Resources Information Center

Podschuweit, Sören; Bernholt, Sascha; Brückmann, Maja

2016-01-01

Background: Complexity models have provided a suitable framework in various domains to assess students' educational achievement. Complexity is often used as the analytical focus when regarding learning outcomes, i.e. when analyzing written tests or problem-centered interviews. Numerous studies reveal negative correlations between the complexity of…

Virtual Simulations and Serious Games in a Laptop-Based University: Gauging Faculty and Student Perceptions

ERIC Educational Resources Information Center

Kapralos, Bill; Hogan, Michelle; Pribetic, Antonin I.; Dubrowski, Adam

2011-01-01

Purpose: Gaming and interactive virtual simulation environments support a learner-centered educational model allowing learners to work through problems acquiring knowledge through an active, experiential learning approach. To develop effective virtual simulations and serious games, the views and perceptions of learners and educators must be…

Leveraging Educational Data Mining for Real-Time Performance Assessment of Scientific Inquiry Skills within Microworlds

ERIC Educational Resources Information Center

Gobert, Janice D.; Sao Pedro, Michael A.; Baker, Ryan S. J. D.; Toto, Ermal; Montalvo, Orlando

2012-01-01

We present "Science Assistments," an interactive environment, which assesses students' inquiry skills as they engage in inquiry using science microworlds. We frame our variables, tasks, assessments, and methods of analyzing data in terms of "evidence-centered design." Specifically, we focus on the "student model," the…

Coupled Facility/Payload Vibration Modeling Improvements

NASA Technical Reports Server (NTRS)

Carnahan, Timothy M.; Kaiser, Michael

2015-01-01

A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at NASA/GSFC there is an analysis to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combination of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

An interactive web application for visualizing climate data

USGS Publications Warehouse

Alder, J.; Hostetler, S.; Williams, D.

2013-01-01

Massive volumes of data are being created as modeling centers from around the world finalize their submission of climate simulations for the Coupled Model Intercomparison Project, phase 5 (CMIP5), in preparation for the forthcoming Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Scientists, resource managers, and other potential users of climate data are faced with the daunting task of analyzing, distilling, and summarizing this unprecedented wealth of climate information.

An Interactive Web Application for Visualizing Climate Data

NASA Astrophysics Data System (ADS)

Alder, J.; Hostetler, S.; Williams, D.

2013-05-01

Massive volumes of data are being created as modeling centers from around the world finalize their submission of climate simulations for the Coupled Model Intercomparison Project, phase 5 (CMIP5), in preparation for the forthcoming Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Scientists, resource managers, and other potential users of climate data are faced with the daunting task of analyzing, distilling, and summarizing this unprecedented wealth of climate information.

The National Center for Collaboration in Medical Modeling and Simulation

DTIC Science & Technology

2005-05-01

universities) to determine the best development strategies . The M~dical Modeling and Simulation Database (MMSD) has been created. The MMSD consists of two web... learner to obtain experience and skill prior to interacting with patients in vivo. The increasing focus on issues of patient safety, health care costs...additional option when considering how to best to maximize their educational resources. While the results of this study suggest that VR simulators are useful

Overview of the GRC Stirling Convertor System Dynamic Model

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Regan, Timothy F.

2004-01-01

A Stirling Convertor System Dynamic Model has been developed at the Glenn Research Center for controls, dynamics, and systems development of free-piston convertor power systems. It models the Stirling cycle thermodynamics, heat flow, gas, mechanical, and mounting dynamics, the linear alternator, and the controller. The model's scope extends from the thermal energy input to thermal, mechanical dynamics, and electrical energy out, allowing one to study complex system interactions among subsystems. The model is a non-linear time-domain model containing sub-cycle dynamics, allowing it to simulate transient and dynamic phenomena that other models cannot. The model details and capability are discussed.

Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions

DOE PAGES

Xu, Shuozhi; Xiong, Liming; Chen, Youping; ...

2017-04-26

Dislocation/stacking fault interactions play an important role in the plastic deformation of metallic nanocrystals and polycrystals. These interactions have been explored in atomistic models, which are limited in scale length by high computational cost. In contrast, multiscale material modeling approaches have the potential to simulate the same systems at a fraction of the computational cost. In this paper, we validate the concurrent atomistic-continuum (CAC) method on the interactions between a lattice screw dislocation and a stacking fault (SF) in three face-centered cubic metallic materials—Ni, Al, and Ag. Two types of SFs are considered: intrinsic SF (ISF) and extrinsic SF (ESF).more » For the three materials at different strain levels, two screw dislocation/ISF interaction modes (annihilation of the ISF and transmission of the dislocation across the ISF) and three screw dislocation/ESF interaction modes (transformation of the ESF into a three-layer twin, transformation of the ESF into an ISF, and transmission of the dislocation across the ESF) are identified. Here, our results show that CAC is capable of accurately predicting the dislocation/SF interaction modes with greatly reduced DOFs compared to fully-resolved atomistic simulations.« less

Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions

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

Xu, Shuozhi; Xiong, Liming; Chen, Youping

Dislocation/stacking fault interactions play an important role in the plastic deformation of metallic nanocrystals and polycrystals. These interactions have been explored in atomistic models, which are limited in scale length by high computational cost. In contrast, multiscale material modeling approaches have the potential to simulate the same systems at a fraction of the computational cost. In this paper, we validate the concurrent atomistic-continuum (CAC) method on the interactions between a lattice screw dislocation and a stacking fault (SF) in three face-centered cubic metallic materials—Ni, Al, and Ag. Two types of SFs are considered: intrinsic SF (ISF) and extrinsic SF (ESF).more » For the three materials at different strain levels, two screw dislocation/ISF interaction modes (annihilation of the ISF and transmission of the dislocation across the ISF) and three screw dislocation/ESF interaction modes (transformation of the ESF into a three-layer twin, transformation of the ESF into an ISF, and transmission of the dislocation across the ESF) are identified. Here, our results show that CAC is capable of accurately predicting the dislocation/SF interaction modes with greatly reduced DOFs compared to fully-resolved atomistic simulations.« less

Combustion of Interacting Droplet Arrays in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Dietrich, D. L.; Struk, P. M.; Ikegami, M.; Nagaishi, H.; Honma, S.; Ikeda, K.

2001-01-01

Investigations into droplet interactions date back to Rex et al. Annamalai and Ryan and Annamalai published extensive reviews of droplet array and cloud combustion studies. In the majority of the reviewed studies, the authors examined the change in the burning rate constant, k, (relative to that of the single droplet) that results from interactions. More recently, Niioka and co-workers have examined ignition and flame propagation along arrays of interacting droplets with the goal of relating these phenomena in this simplified geometry to the more practical spray configuration. Our work has focussed on droplet interactions under conditions where flame extinction occurs at a finite droplet diameter. In our previous work, we reported that in normal gravity, reduced pressure conditions, droplet interactions improved flame stability and extended flammability limits (by inference). In our recent work, we examine droplet interactions under conditions where the flame extinguishes at a finite droplet diameter in microgravity. The microgravity experiments were in the NASA GRC 2.2 and 5.2 second drop towers, and the JAMIC (Japan Microgravity Center) 10 second drop tower. We also present progress on a numerical model of single droplet combustion that is in the process of being extended to model a binary droplet array.

Variable-centered and person-centered approaches to studying Mexican-origin mother-daughter cultural orientation dissonance.

PubMed

Bámaca-Colbert, Mayra Y; Gayles, Jochebed G

2010-11-01

The overall aim of the current study was to identify the methodological approach and corresponding analytic procedure that best elucidated the associations among Mexican-origin mother-daughter cultural orientation dissonance, family functioning, and adolescent adjustment. To do so, we employed, and compared, two methodological approaches (i.e., variable-centered and person-centered) via four analytic procedures (i.e., difference score, interactive, matched/mismatched grouping, and latent profiles). The sample consisted of 319 girls in the 7th or 10th grade and their mother or mother figure from a large Southwestern, metropolitan area in the US. Family factors were found to be important predictors of adolescent adjustment in all models. Although some findings were similar across all models, overall, findings suggested that the latent profile procedure best elucidated the associations among the variables examined in this study. In addition, associations were present across early and middle adolescents, with a few findings being only present for one group. Implications for using these analytic procedures in studying cultural and family processes are discussed.

The Value of Reliable Data: Interactive Data Tools from the National Comprehensive Center for Teacher Quality. Policy-to-Practice Brief. Number 1

ERIC Educational Resources Information Center

National Comprehensive Center for Teacher Quality, 2008

2008-01-01

The National Comprehensive Center for Teacher Quality (TQ Center) designed the Interactive Data Tools to provide users with access to state and national data that can be helpful in assessing the qualifications of teachers in the states and the extent to which a state's teacher policy climate generally supports teacher quality. The Interactive Data…

Investigation of energy transfer in terbium doped Y 2SiO5 phosphor particles

NASA Astrophysics Data System (ADS)

Salis, M.; Carbonaro, C. M.; Corpino, R.; Anedda, A.; Ricci, P. C.

2012-07-01

The kinetics of luminescence of sol-gel synthesized terbium doped Y 2SiO5 (YSO) phosphor particles is investigated in detail with reference to Tb concentration in the 0.001%-10% range. By increasing the dopant concentration, the luminescence profile changes from a blue to a green peaked emission spectrum because of the energy transfer among centers. The inter-center energy transfer mechanism is well accounted for by the Inokuti-Hirayama (IH) kinetic model which is based on a statistical average of inter-center distance dependent decay modes of the donor luminescence. The distribution of the decay modes is implemented from the Förster-Dexter resonance theory of energy transfer by assuming a rate constant for the energy transfer by multipolar interactions between donors and acceptors. However, the experimental results recorded in the low concentration limit show the presence of green emission contributions in the luminescence spectrum which cannot be related to the Tb concentration; for this reason an additional internal energy transfer mechanism, occurring among levels of the same center, is proposed to account for the recorded emission properties. Thus, a new and more exhaustive model which includes both the internal and external energy transfer processes is considered; the proposed model allows a better explanation of the spectroscopic features of Tb related centers in YSO crystals and discloses the critical concentration and the quantum yields of the different energy transfer mechanisms.

The ARPAL operational high resolution Poor Man's Ensemble, description and validation

NASA Astrophysics Data System (ADS)

Corazza, Matteo; Sacchetti, Davide; Antonelli, Marta; Drofa, Oxana

2018-05-01

The Meteo Hydrological Functional Center for Civil Protection of the Environmental Protection Agency of the Liguria Region is responsible for issuing forecasts primarily aimed at the Civil Protection needs. Several deterministic high resolution models, run every 6 or 12 h, are regularly used in the Center to elaborate weather forecasts at short to medium range. The Region is frequently affected by severe flash floods over its very small basins, characterized by a steep orography close to the sea. These conditions led the Center in the past years to pay particular attention to the use and development of high resolution model chains for explicit simulation of convective phenomena. For years, the availability of several models has been used by the forecasters for subjective analyses of the potential evolution of the atmosphere and of its uncertainty. More recently, an Interactive Poor Man's Ensemble has been developed, aimed at providing statistical ensemble variables to help forecaster's evaluations. In this paper the structure of this system is described and results are validated using the regional dense ground observational network.

Aerodynamic Analyses and Database Development for Lift-Off/Transition and First Stage Ascent of the Ares I A106 Vehicle

NASA Technical Reports Server (NTRS)

Pamadi, Bandu N.; Pei, Jing; Covell, Peter F.; Favaregh, Noah M.; Gumbert, Clyde R.; Hanke, Jeremy L.

2011-01-01

NASA Langley Research Center, in partnership with NASA Marshall Space Flight Center and NASA Ames Research Center, was involved in the aerodynamic analyses, testing, and database development for the Ares I A106 crew launch vehicle in support of the Ares Design and Analysis Cycle. This paper discusses the development of lift-off/transition and ascent databases. The lift-off/transition database was developed using data from tests on a 1.75% scale model of the A106 configuration in the NASA Langley 14x22 Subsonic Wind Tunnel. The power-off ascent database was developed using test data on a 1% A106 scale model from two different facilities, the Boeing Polysonic Wind Tunnel and the NASA Langley Unitary Plan Wind Tunnel. The ascent database was adjusted for differences in wind tunnel and flight Reynolds numbers using USM3D CFD code. The aerodynamic jet interaction effects due to first stage roll control system were modeled using USM3D and OVERFLOW CFD codes.

Measuring the Interactive Skills of Caregivers in Child Care Centers: Development and Validation of the Caregiver Interaction Profile Scales

ERIC Educational Resources Information Center

Helmerhorst, Katrien O. W.; Riksen-Walraven, J. Marianne; Vermeer, Harriet J.; Fukkink, Ruben G.; Tavecchio, Louis W. C.

2014-01-01

Research Findings: High-quality caregiver-child interactions constitute the core of high-quality child care for young children. This article describes the background and development of the Caregiver Interaction Profile (CIP) scales to rate 6 key skills of caregivers for interacting with 0-to 4-year-old children in child care centers: sensitive…

Citizen centered health and lifestyle management via interactive TV: The PANACEIA-ITV health system.

PubMed

Maglaveras, N; Chouvarda, I; Koutkias, V; Lekka, I; Tsakali, M; Tsetoglou, S; Maglavera, S; Leondaridis, L; Zeevi, B; Danelli, V; Kotis, T; De Moore, G; Balas, E A

2003-01-01

In the context of an IST European project with acronym PANACEIA-ITV, a home care service provisioning system is described, based on interactive TV technology. The purpose of PANACEIA-ITV is to facilitate essential lifestyle changes and to promote compliance with scientifically sound self-care recommendations, through the application of interactive digital television for family health maintenance. The means to achieve these goals are based on technological, health services and business models. PANACEIA-ITV is looking for communication of monitoring micro-devices with I-TV set-top-boxes using infrared technology, and embodiment of analogous H/W and S/W in the I-TV set-top-boxes. Intelligent agents are used to regulate data flow, user queries as well as service provisions from and to the household through the satellite digital platform, the portal and the back-end decision support mechanisms, using predominantly the Active Service Provision (ASP) model. Moreover, interactive digital TV services are developed for the delivery of health care in the home care environment.

More accurate depiction of adsorption energy on transition metals using work function as one additional descriptor.

PubMed

Shen, Xiaochen; Pan, Yanbo; Liu, Bin; Yang, Jinlong; Zeng, Jie; Peng, Zhenmeng

2017-05-24

The reaction mechanism and properties of a catalytic process are primarily determined by the interactions between reacting species and catalysts. However, the interactions are often challenging to be experimentally measured, especially for unstable intermediates. Therefore, it is of significant importance to establish an exact relationship between chemical-catalyst interactions and catalyst parameters, which will allow calculation of these interactions and thus advance their mechanistic understanding. Herein we report the description of adsorption energy on transition metals by considering both ionic bonding and covalent bonding contributions and introduce the work function as one additional responsible parameter. We find that the adsorption energy can be more accurately described using a two-dimensional (2D) polynomial model, which shows a significant improvement compared with the current adsorption energy-d-band center linear correlation. We also demonstrate the utilization of this new 2D polynomial model to calculate oxygen binding energy of different transition metals to help understand their catalytic properties in oxygen reduction reactions.

Fatigue Moderates the Relationship Between Perceived Stress and Suicidal Ideation: Evidence From Two High-Resolution Studies.

PubMed

Kleiman, Evan M; Turner, Brianna J; Chapman, Alexander L; Nock, Matthew K

2018-01-01

Theoretical models of self-harm suggest that high perceived stress and high fatigue (which might affect the ability to cope with stress) may interact to predict the short-term occurrence of suicidal ideation and nonsuicidal self-injury (NSSI). We tested 3 approaches to examining this interaction, each of which provided a different understanding of the specific nature of these associations: comparing each individual's daily stress/fatigue to the entire sample's overall average (i.e., grand-mean centering), comparing each individual's daily perceived stress/fatigue to his or her overall average (i.e., group- or participant-mean centering), and comparing each individual's average perceived stress/fatigue to the sample's overall average (i.e., centering participant means on overall grand mean). In 2 studies, adolescents (n = 30; 574 daily reports, M age = 17.3 years, range = 12-19; 87.6% female) and young adults (n = 60; 698 daily reports; M age = 23.25 years, range = 18-35; 85% female) completed daily measures of perceived stress, fatigue, suicidal ideation, and NSSI. In both samples, the interaction between high daily perceived stress and high daily fatigue predicted greater odds of daily suicidal ideation (but not NSSI). Only the model comparing each individual's daily stress/fatigue to the entire sample's overall average was consistently significant across the two studies. Participants were most likely to experience suicidal ideation on days when both perceived stress and fatigue were elevated relative to the average level experienced across people and time points. Studies should build upon these findings with more in-depth examination of the temporal nature of stability and change in these factors as they relate to sustained suicidal ideation.

The multiscale coarse-graining method. XI. Accurate interactions based on the centers of charge of coarse-grained sites

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

Cao, Zhen; Voth, Gregory A., E-mail: gavoth@uchicago.edu

It is essential to be able to systematically construct coarse-grained (CG) models that can efficiently and accurately reproduce key properties of higher-resolution models such as all-atom. To fulfill this goal, a mapping operator is needed to transform the higher-resolution configuration to a CG configuration. Certain mapping operators, however, may lose information related to the underlying electrostatic properties. In this paper, a new mapping operator based on the centers of charge of CG sites is proposed to address this issue. Four example systems are chosen to demonstrate this concept. Within the multiscale coarse-graining framework, CG models that use this mapping operatormore » are found to better reproduce the structural correlations of atomistic models. The present work also demonstrates the flexibility of the mapping operator and the robustness of the force matching method. For instance, important functional groups can be isolated and emphasized in the CG model.« less

A patient-centered pharmacy services model of HIV patient care in community pharmacy settings: a theoretical and empirical framework.

PubMed

Kibicho, Jennifer; Owczarzak, Jill

2012-01-01

Reflecting trends in health care delivery, pharmacy practice has shifted from a drug-specific to a patient-centered model of care, aimed at improving the quality of patient care and reducing health care costs. In this article, we outline a theoretical model of patient-centered pharmacy services (PCPS), based on in-depth, qualitative interviews with a purposive sample of 28 pharmacists providing care to HIV-infected patients in specialty, semispecialty, and nonspecialty pharmacy settings. Data analysis was an interactive process informed by pharmacists' interviews and a review of the general literature on patient centered care, including Medication Therapy Management (MTM) services. Our main finding was that the current models of pharmacy services, including MTM, do not capture the range of pharmacy services in excess of mandated drug dispensing services. In this article, we propose a theoretical PCPS model that reflects the actual services pharmacists provide. The model includes five elements: (1) addressing patients as whole, contextualized persons; (2) customizing interventions to unique patient circumstances; (3) empowering patients to take responsibility for their own health care; (4) collaborating with clinical and nonclinical providers to address patient needs; and (5) developing sustained relationships with patients. The overarching goal of PCPS is to empower patients' to take responsibility for their own health care and self-manage their HIV-infection. Our findings provide the foundation for future studies regarding how widespread these practices are in diverse community settings, the validity of the proposed PCPS model, the potential for standardizing pharmacist practices, and the feasibility of a PCPS framework to reimburse pharmacists services.

First-Principles Molecular Dynamics Studies of Organometallic Complexes and Homogeneous Catalytic Processes.

PubMed

Vidossich, Pietro; Lledós, Agustí; Ujaque, Gregori

2016-06-21

Computational chemistry is a valuable aid to complement experimental studies of organometallic systems and their reactivity. It allows probing mechanistic hypotheses and investigating molecular structures, shedding light on the behavior and properties of molecular assemblies at the atomic scale. When approaching a chemical problem, the computational chemist has to decide on the theoretical approach needed to describe electron/nuclear interactions and the composition of the model used to approximate the actual system. Both factors determine the reliability of the modeling study. The community dedicated much effort to developing and improving the performance and accuracy of theoretical approaches for electronic structure calculations, on which the description of (inter)atomic interactions rely. Here, the importance of the model system used in computational studies is highlighted through examples from our recent research focused on organometallic systems and homogeneous catalytic processes. We show how the inclusion of explicit solvent allows the characterization of molecular events that would otherwise not be accessible in reduced model systems (clusters). These include the stabilization of nascent charged fragments via microscopic solvation (notably, hydrogen bonding), transfer of charge (protons) between distant fragments mediated by solvent molecules, and solvent coordination to unsaturated metal centers. Furthermore, when weak interactions are involved, we show how conformational and solvation properties of organometallic complexes are also affected by the explicit inclusion of solvent molecules. Such extended model systems may be treated under periodic boundary conditions, thus removing the cluster/continuum (or vacuum) boundary, and require a statistical mechanics simulation technique to sample the accessible configurational space. First-principles molecular dynamics, in which atomic forces are computed from electronic structure calculations (namely, density functional theory), is certainly the technique of choice to investigate chemical events in solution. This methodology is well established and thanks to advances in both algorithms and computational resources simulation times required for the modeling of chemical events are nowadays accessible, though the computational requirements use to be high. Specific applications reviewed here include mechanistic studies of the Shilov and Wacker processes, speciation in Pd chemistry, hydrogen bonding to metal centers, and the dynamics of agostic interactions.

A Fluid Structure Algorithm with Lagrange Multipliers to Model Free Swimming

NASA Astrophysics Data System (ADS)

Sahin, Mehmet; Dilek, Ezgi

2017-11-01

A new monolithic approach is prosed to solve the fluid-structure interaction (FSI) problem with Lagrange multipliers in order to model free swimming/flying. In the present approach, the fluid domain is modeled by the incompressible Navier-Stokes equations and discretized using an Arbitrary Lagrangian-Eulerian (ALE) formulation based on the stable side-centered unstructured finite volume method. The solid domain is modeled by the constitutive laws for the nonlinear Saint Venant-Kirchhoff material and the classical Galerkin finite element method is used to discretize the governing equations in a Lagrangian frame. In order to impose the body motion/deformation, the distance between the constraint pair nodes is imposed using the Lagrange multipliers, which is independent from the frame of reference. The resulting algebraic linear equations are solved in a fully coupled manner using a dual approach (null space method). The present numerical algorithm is initially validated for the classical FSI benchmark problems and then applied to the free swimming of three linked ellipses. The authors are grateful for the use of the computing resources provided by the National Center for High Performance Computing (UYBHM) under Grant Number 10752009 and the computing facilities at TUBITAK-ULAKBIM, High Performance and Grid Computing Center.

Development of a Multicenter Density Functional Tight Binding Model for Plutonium Surface Hydriding.

PubMed

Goldman, Nir; Aradi, Bálint; Lindsey, Rebecca K; Fried, Laurence E

2018-05-08

We detail the creation of a multicenter density functional tight binding (DFTB) model for hydrogen on δ-plutonium, using a framework of new Slater-Koster interaction parameters and a repulsive energy based on the Chebyshev Interaction Model for Efficient Simulation (ChIMES), where two- and three-center atomic interactions are represented by linear combinations of Chebyshev polynomials. We find that our DFTB/ChIMES model yields a total electron density of states for bulk δ-Pu that compares well to that from Density Functional Theory, as well as to a grid of energy calculations representing approximate H 2 dissociation paths on the δ-Pu (100) surface. We then perform molecular dynamics simulations and minimum energy pathway calculations to determine the energetics of surface dissociation and subsurface diffusion on the (100) and (111) surfaces. Our approach allows for the efficient creation of multicenter repulsive energies with a relatively small investment in initial DFT calculations. Our efforts are particularly pertinent to studies that rely on quantum calculations for interpretation and validation, such as experimental determination of chemical reactivity both on surfaces and in condensed phases.

University of California San Francisco (UCSF-1): Chemical-Genetic Interaction Mapping Strategy | Office of Cancer Genomics

Cancer.gov

The CTD2 Center at University of California San Francisco (UCSF-1) developed a chemical-genetic interaction mapping strategy to uncover the impact of cancer gene expression on responses to a panel of emerging therapeutics. To study the impact of aberrant gene activity in isolation, they developed an isogenic model of triple-negative breast cancer (TNBC) using the hormone receptor negative MCF10A non-tumorigenic cell line derived from healthy breast tissue which is diploid and largely devoid of somatic alterations.

Interaction location outweighs the competitive advantage of numerical superiority in Cebus capucinus intergroup contests

PubMed Central

Crofoot, Margaret C.; Gilby, Ian C.; Wikelski, Martin C.; Kays, Roland W.

2008-01-01

Numerical superiority confers a competitive advantage during contests among animal groups, shaping patterns of resource access, and, by extension, fitness. However, relative group size does not always determine the winner of intergroup contests. Smaller, presumably weaker social groups often defeat their larger neighbors, but how and when they are able to do so remains poorly understood. Models of competition between individuals suggest that location may influence contest outcome. However, because of the logistical difficulties of studying intergroup interactions, previous studies have been unable to determine how contest location and group size interact to shape relationships among groups. We address this question by using an automated radio telemetry system to study intergroup interactions among six capuchin monkey (Cebus capucinus) social groups of varying sizes. We find that the odds of winning increase with relative group size; one additional group member increases the odds of winning an interaction by 10%. However, this effect is not uniform across space; with each 100 m that a group moves away from the center of its home range, its odds of winning an interaction decrease by 31%. We demonstrate that contest outcome depends on an interaction between group size and location, such that small groups can defeat much larger groups near the center of their home range. The tendency of resident groups to win contests may help explain how small groups persist in areas with intense intergroup competition. PMID:18184811

Numerical Analysis of Mixed-Phase Icing Cloud Simulations in the NASA Propulsion Systems Laboratory

NASA Technical Reports Server (NTRS)

Bartkus, Tadas; Tsao, Jen-Ching; Struk, Peter; Van Zante, Judith

2017-01-01

This presentation describes the development of a numerical model that couples the thermal interaction between ice particles, water droplets, and the flowing gas of an icing wind tunnel for simulation of NASA Glenn Research Centers Propulsion Systems Laboratory (PSL). The ultimate goal of the model is to better understand the complex interactions between the test parameters and have greater confidence in the conditions at the test section of the PSL tunnel. The model attempts to explain the observed changes in test conditions by coupling the conservation of mass and energy equations for both the cloud particles and flowing gas mass. Model predictions were compared to measurements taken during May 2015 testing at PSL, where test conditions varied gas temperature, pressure, velocity and humidity levels, as well as the cloud total water content, particle initial temperature, and particle size distribution.

Numerical Analysis of Mixed-Phase Icing Cloud Simulations in the NASA Propulsion Systems Laboratory

NASA Technical Reports Server (NTRS)

Bartkus, Tadas P.; Tsao, Jen-Ching; Struk, Peter M.; Van Zante, Judith F.

2017-01-01

This paper describes the development of a numerical model that couples the thermal interaction between ice particles, water droplets, and the flowing gas of an icing wind tunnel for simulation of NASA Glenn Research Centers Propulsion Systems Laboratory (PSL). The ultimate goal of the model is to better understand the complex interactions between the test parameters and have greater confidence in the conditions at the test section of the PSL tunnel. The model attempts to explain the observed changes in test conditions by coupling the conservation of mass and energy equations for both the cloud particles and flowing gas mass. Model predictions were compared to measurements taken during May 2015 testing at PSL, where test conditions varied gas temperature, pressure, velocity and humidity levels, as well as the cloud total water content, particle initial temperature, and particle size distribution.

Chemical supply chain modeling for analysis of homeland security events

DOE PAGES

Ehlen, Mark A.; Sun, Amy C.; Pepple, Mark A.; ...

2013-09-06

The potential impacts of man-made and natural disasters on chemical plants, complexes, and supply chains are of great importance to homeland security. To be able to estimate these impacts, we developed an agent-based chemical supply chain model that includes: chemical plants with enterprise operations such as purchasing, production scheduling, and inventories; merchant chemical markets, and multi-modal chemical shipments. Large-scale simulations of chemical-plant activities and supply chain interactions, running on desktop computers, are used to estimate the scope and duration of disruptive-event impacts, and overall system resilience, based on the extent to which individual chemical plants can adjust their internal operationsmore » (e.g., production mixes and levels) versus their external interactions (market sales and purchases, and transportation routes and modes). As a result, to illustrate how the model estimates the impacts of a hurricane disruption, a simple example model centered on 1,4-butanediol is presented.« less

EEGLAB, SIFT, NFT, BCILAB, and ERICA: New Tools for Advanced EEG Processing

PubMed Central

Delorme, Arnaud; Mullen, Tim; Kothe, Christian; Akalin Acar, Zeynep; Bigdely-Shamlo, Nima; Vankov, Andrey; Makeig, Scott

2011-01-01

We describe a set of complementary EEG data collection and processing tools recently developed at the Swartz Center for Computational Neuroscience (SCCN) that connect to and extend the EEGLAB software environment, a freely available and readily extensible processing environment running under Matlab. The new tools include (1) a new and flexible EEGLAB STUDY design facility for framing and performing statistical analyses on data from multiple subjects; (2) a neuroelectromagnetic forward head modeling toolbox (NFT) for building realistic electrical head models from available data; (3) a source information flow toolbox (SIFT) for modeling ongoing or event-related effective connectivity between cortical areas; (4) a BCILAB toolbox for building online brain-computer interface (BCI) models from available data, and (5) an experimental real-time interactive control and analysis (ERICA) environment for real-time production and coordination of interactive, multimodal experiments. PMID:21687590

Primary immunodeficiency disease: a model for case management of chronic diseases.

PubMed

Burton, Janet; Murphy, Elyse; Riley, Patty

2010-01-01

Patient-centered chronic care management is a new model for the management of rare chronic diseases such as primary immunodeficiency disease (PIDD). This approach emphasizes helping patients become experts on the management of their disease as informed, involved, and interactive partners in healthcare decisions with providers. Because only a few patients are affected by rare illnesses, these patients are forced to become knowledgeable about their disease and therapies and to seek treatment from a healthcare team, which includes physicians and nurse specialists who are equipped to manage the complexity of the disease and its comorbidities. Importantly, therapy for PIDD can be self-administered at home, which has encouraged the transition toward a proactive stance that is at the heart of patient-centered chronic care management. We discuss the evolution of therapy, the issues with the disease, and challenges with its management within the framework of other chronic disease management programs. Suggestions and rationale to move case management of PIDD forward are presented with the intent that sharing our experiences will improve process and better manage outcomes in this patient population. The patient-centered model for the management of PIDD is applicable to the primary care settings, where nurse case managers assist patients through education, support them and their families, and facilitate access to community resources in an approach, which has been described as "guided care." The model also applies specifically to immunology centers where patients receive treatment or instruction on its self-administration at home. Patient-centered management of PIDD, with its emphasis on full involvement of patients in their treatment, has the potential to improve compliance with treatment, and thus patient outcomes, as well as patients' quality of life. The patient-centered model expands the traditional model of chronic disease management, which relies on evidence-based medicine, provider expertise, clinical information systems, and patient education. This approach supports patient self-management with strategies that empower and prepare them for their role as expert patients.

Continuation of research in software for space operations support

NASA Technical Reports Server (NTRS)

Collier, Mark D.

1989-01-01

Software technologies relevant to workstation executives are discussed. Evaluations of problems, potential or otherwise, seen with IBM's Workstation Executive (WEX) 2.5 preliminary design and applicable portions of the 2.5 critical design are presented. Diverse graphics requirements of the Johnson Space Center's Mission Control Center Upgrade (MCCU) are also discussed. The key is to use tools that are portable, compatible with the X window system, and best suited to the requirements of the associated application. This will include a User Interface Language (UIL), an interactive display builder, and a graphic plotting/modeling system. Work sheets are provided for POSIX 1003.4 real-time extensions and the requirements for the Center's automated information systems security plan, referred to as POSIX 1003.6, are discussed.

Predictive Modeling in Actinide Chemistry and Catalysis

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

Yang, Ping

2016-05-16

These are slides from a presentation on predictive modeling in actinide chemistry and catalysis. The following topics are covered in these slides: Structures, bonding, and reactivity (bonding can be quantified by optical probes and theory, and electronic structures and reaction mechanisms of actinide complexes); Magnetic resonance properties (transition metal catalysts with multi-nuclear centers, and NMR/EPR parameters); Moving to more complex systems (surface chemistry of nanomaterials, and interactions of ligands with nanoparticles); Path forward and conclusions.

Student Research Projects

NASA Technical Reports Server (NTRS)

Yeske, Lanny A.

1998-01-01

Numerous FY1998 student research projects were sponsored by the Mississippi State University Center for Air Sea Technology. This technical note describes these projects which include research on: (1) Graphical User Interfaces, (2) Master Environmental Library, (3) Database Management Systems, (4) Naval Interactive Data Analysis System, (5) Relocatable Modeling Environment, (6) Tidal Models, (7) Book Inventories, (8) System Analysis, (9) World Wide Web Development, (10) Virtual Data Warehouse, (11) Enterprise Information Explorer, (12) Equipment Inventories, (13) COADS, and (14) JavaScript Technology.

Intermolecular Interactions and Electrostatic Properties of the [beta]-Hydroquinone Apohost: Implications for Supramolecular Chemistry

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

Clausen, Henrik F.; Chen, Yu-Sheng; Jayatilaka, Dylan

2012-02-07

The crystal structure of the {beta}-polymorph of hydroquinone ({beta}-HQ), the apohost of a large family of clathrates, is reported with a specific focus on intermolecular interactions and the electrostatic nature of its cavity. Hirshfeld surface analysis reveals subtle close contacts between two interconnecting HQ networks, and the local packing and related close contacts were examined by breakdown of the fingerprint plot. An experimental multipole model containing anisotropic thermal parameters for hydrogen atoms has been successfully refined against 15(2) K single microcrystal synchrotron X-ray diffraction data. The experimental electron density model has been compared with a theoretical electron density calculated withmore » the molecule embedded in its own crystal field. Hirshfeld charges, interaction energies and the electrostatic potential calculated for both models are qualitatively in good agreement, but small differences in the electrostatic potential persist due to charge transfer from all hydrogen atoms to the oxygen atoms in the theoretical model. The electrostatic potential in the center of the cavity is positive, very shallow and highly symmetric, suggesting that the inclusion of polar molecules in the void will involve a balance between opposing effects. The electric field is by symmetry zero in the center of the cavity, increasing to a value of 0.0185 e/{angstrom}{sup 2} (0.27 V/{angstrom}) 1 {angstrom} along the 3-fold axis and 0.0105 e/{angstrom}{sup 2} (0.15 V/{angstrom}) 1 {angstrom} along the perpendicular direction. While these values are substantial in a macroscopic context, they are quite small for a molecular cavity and are not expected to strongly polarize a guest molecule.« less

Methodical and technological aspects of creation of interactive computer learning systems

NASA Astrophysics Data System (ADS)

Vishtak, N. M.; Frolov, D. A.

2017-01-01

The article presents a methodology for the development of an interactive computer training system for training power plant. The methods used in the work are a generalization of the content of scientific and methodological sources on the use of computer-based training systems in vocational education, methods of system analysis, methods of structural and object-oriented modeling of information systems. The relevance of the development of the interactive computer training systems in the preparation of the personnel in the conditions of the educational and training centers is proved. Development stages of the computer training systems are allocated, factors of efficient use of the interactive computer training system are analysed. The algorithm of work performance at each development stage of the interactive computer training system that enables one to optimize time, financial and labor expenditure on the creation of the interactive computer training system is offered.

New statistical potential for quality assessment of protein models and a survey of energy functions

PubMed Central

2010-01-01

Background Scoring functions, such as molecular mechanic forcefields and statistical potentials are fundamentally important tools in protein structure modeling and quality assessment. Results The performances of a number of publicly available scoring functions are compared with a statistical rigor, with an emphasis on knowledge-based potentials. We explored the effect on accuracy of alternative choices for representing interaction center types and other features of scoring functions, such as using information on solvent accessibility, on torsion angles, accounting for secondary structure preferences and side chain orientation. Partially based on the observations made, we present a novel residue based statistical potential, which employs a shuffled reference state definition and takes into account the mutual orientation of residue side chains. Atom- and residue-level statistical potentials and Linux executables to calculate the energy of a given protein proposed in this work can be downloaded from http://www.fiserlab.org/potentials. Conclusions Among the most influential terms we observed a critical role of a proper reference state definition and the benefits of including information about the microenvironment of interaction centers. Molecular mechanical potentials were also tested and found to be over-sensitive to small local imperfections in a structure, requiring unfeasible long energy relaxation before energy scores started to correlate with model quality. PMID:20226048

NO PLIF Visualizations of the Orion Capsule in LENS-I

NASA Technical Reports Server (NTRS)

Combs, C.; Clemens, N.; Danehy, P. M.; Bathel, B.; Parker, R.; Wadhams, T.; Holden, M.; Kirk, B.

2013-01-01

Planar laser-induced fluorescence (PLIF) of nitric oxide (NO) was used to visualize the interaction of reaction-control-system (RCS) jet flows in the wake of a hypersonic capsule reentry vehicle. The tests were performed at the Calspan University at Buffalo Research Center's (CUBRC) LENS-I reflected shock tunnel facility. This was the first application of PLIF to study RCS jets in a large-scale pulsed hypersonic facility. The LENS-I facility allowed RCS jet flows to be studied while varying the flow enthalpy, Reynolds number, angle of attack and jet configuration. The interaction of pitch and roll jets with the flowfield was investigated. Additionally, thin film sensors were used to monitor heat transfer on the surface of the model to detect any localized heating resulting from the firing of the RCS jets. Tests were conducted with the model held at angles of attack of 18deg and 22deg. The nominal Mach number in all tests was 8, while Reynolds number based on model diameter ranged from 2.2x10(exp 6) - 1.5x10(exp 7). Images were processed using the Virtual Diagnostics Interface (ViDI) system developed at NASA Langley Research Center to provide a three-dimensional display of the experimental data.

Indirect detection of neutrino portal dark matter

NASA Astrophysics Data System (ADS)

Batell, Brian; Han, Tao; Shams Es Haghi, Barmak

2018-05-01

We investigate the feasibility of the indirect detection of dark matter in a simple model using the neutrino portal. The model is very economical, with right-handed neutrinos generating neutrino masses through the type-I seesaw mechanism and simultaneously mediating interactions with dark matter. Given the small neutrino Yukawa couplings expected in a type-I seesaw, direct detection and accelerator probes of dark matter in this scenario are challenging. However, dark matter can efficiently annihilate to right-handed neutrinos, which then decay via active-sterile mixing through the weak interactions, leading to a variety of indirect astronomical signatures. We derive the existing constraints on this scenario from Planck cosmic microwave background measurements, Fermi dwarf spheroidal galaxy and Galactic center gamma-ray observations, and AMS-02 antiproton observations, and we also discuss the future prospects of Fermi and the Cherenkov Telescope Array. Thermal annihilation rates are already being probed for dark matter lighter than about 50 GeV, and this can be extended to dark matter masses of 100 GeV and beyond in the future. This scenario can also provide a dark matter interpretation of the Fermi Galactic center gamma-ray excess, and we confront this interpretation with other indirect constraints. Finally we discuss some of the exciting implications of extensions of the minimal model with large neutrino Yukawa couplings and Higgs portal couplings.

Dark matter with pseudoscalar-mediated interactions explains the DAMA signal and the galactic center excess.

PubMed

Arina, Chiara; Del Nobile, Eugenio; Panci, Paolo

2015-01-09

We study a Dirac dark matter particle interacting with ordinary matter via the exchange of a light pseudoscalar, and analyze its impact on both direct and indirect detection experiments. We show that this candidate can accommodate the long-standing DAMA modulated signal and yet be compatible with all exclusion limits at 99(S)% C.L. This result holds for natural choices of the pseudoscalar-quark couplings (e.g., flavor universal), which give rise to a significant enhancement of the dark matter-proton coupling with respect to the coupling to neutrons. We also find that this candidate can accommodate the observed 1-3 GeV gamma-ray excess at the Galactic center and at the same time have the correct relic density today. The model could be tested with measurements of rare meson decays, flavor changing processes, and searches for axionlike particles with mass in the MeV range.

KSC-2014-3137

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – The grand opening of the new Great Balls of Fire exhibit was held at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Informational displays about future NASA exploration missions are featured along the wall of the new exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Face Centered Cubic SnSe as a Z2 Trivial Dirac Nodal Line Material

NASA Astrophysics Data System (ADS)

Tateishi, Ikuma; Matsuura, Hiroyasu

2018-07-01

The presence of a Dirac nodal line in a time-reversal and inversion symmetric system is dictated by the Z2 index when spin-orbit interaction is absent. In a first principles calculation, we show that a Dirac nodal line can emerge in Z2 trivial material by calculating the band structure of SnSe in a face centered cubic lattice as an example. We qualitatively show that it becomes a topological crystalline insulator when spin-orbit interaction is taken into account. We clarify the origin of the Dirac nodal line by obtaining irreducible representations corresponding to bands and explain the triviality of the Z2 index. We construct an effective model representing the Dirac nodal line using the k · p method, and discuss the Berry phase and a surface state expected from the Dirac nodal line.

Data Visualization and Animation Lab (DVAL) overview

NASA Technical Reports Server (NTRS)

Stacy, Kathy; Vonofenheim, Bill

1994-01-01

The general capabilities of the Langley Research Center Data Visualization and Animation Laboratory is described. These capabilities include digital image processing, 3-D interactive computer graphics, data visualization and analysis, video-rate acquisition and processing of video images, photo-realistic modeling and animation, video report generation, and color hardcopies. A specialized video image processing system is also discussed.

Facilitated Playgroups to Promote Speech and Language Skills of Young Children with Communication Delays: A Pilot Study

ERIC Educational Resources Information Center

Green, Katherine B.; Towson, Jacqueline A.; Head, Cynthia; Janowski, Brittany; Smith, Laura

2018-01-01

Family-centered practices that build caregiver capacity are a central focus of early intervention services for young children with disabilities. The purpose of this study was to evaluate the feasibility of adapting the "Parents Interacting with Infants" (PIWI) facilitated playgroup model to target effective communication strategies for…

Research in Modeling and Simulation for Airspace Systems Innovation

NASA Technical Reports Server (NTRS)

Ballin, Mark G.; Kimmel, William M.; Welch, Sharon S.

2007-01-01

This viewgraph presentation provides an overview of some of the applied research and simulation methodologies at the NASA Langley Research Center that support aerospace systems innovation. Risk assessment methodologies, complex systems design and analysis methodologies, and aer ospace operations simulations are described. Potential areas for future research and collaboration using interactive and distributed simula tions are also proposed.

PEO Integration Acronym Book

DTIC Science & Technology

2011-02-01

Command CASE Computer Aided Software Engineering CASEVAC Casualty Evacuation CASTFOREM Combined Arms And Support Task Force Evaluation Model CAT Center For...Advanced Technologies CAT Civil Affairs Team CAT Combined Arms Training CAT Crew Integration CAT Crisis Action Team CATIA Computer-Aided Three...Dimensional Interactive Application CATOX Catalytic Oxidation CATS Combined Arms Training Strategy CATT Combined Arms Tactical Trainer CATT Computer

Unique life sciences research facilities at NASA Ames Research Center

NASA Technical Reports Server (NTRS)

Mulenburg, G. M.; Vasques, M.; Caldwell, W. F.; Tucker, J.

1994-01-01

The Life Science Division at NASA's Ames Research Center has a suite of specialized facilities that enable scientists to study the effects of gravity on living systems. This paper describes some of these facilities and their use in research. Seven centrifuges, each with its own unique abilities, allow testing of a variety of parameters on test subjects ranging from single cells through hardware to humans. The Vestibular Research Facility allows the study of both centrifugation and linear acceleration on animals and humans. The Biocomputation Center uses computers for 3D reconstruction of physiological systems, and interactive research tools for virtual reality modeling. Psycophysiological, cardiovascular, exercise physiology, and biomechanical studies are conducted in the 12 bed Human Research Facility and samples are analyzed in the certified Central Clinical Laboratory and other laboratories at Ames. Human bedrest, water immersion and lower body negative pressure equipment are also available to study physiological changes associated with weightlessness. These and other weightlessness models are used in specialized laboratories for the study of basic physiological mechanisms, metabolism and cell biology. Visual-motor performance, perception, and adaptation are studied using ground-based models as well as short term weightlessness experiments (parabolic flights). The unique combination of Life Science research facilities, laboratories, and equipment at Ames Research Center are described in detail in relation to their research contributions.

Physician Interactions with Electronic Health Records in Primary Care

PubMed Central

Montague, Enid; Asan, Onur

2013-01-01

Objective It is essential to design technologies and systems that promote appropriate interactions between physicians and patients. This study explored how physicians interact with Electronic Health Records (EHRs) to understand the qualities of the interaction between the physician and the EHR that may contribute to positive physician-patient interactions. Study Design Video-taped observations of 100 medical consultations were used to evaluate interaction patterns between physicians and EHRs. Quantified observational methods were used to contribute to ecological validity. Methods Ten primary care physicians and 100 patients from five clinics participated in the study. Clinical encounters were recorded with video cameras and coded using a validated objective coding methodology in order to examine how physicians interact with electronic health records. Results Three distinct styles were identified that characterize physician interactions with the EHR: technology-centered, human-centered, and mixed. Physicians who used a technology-centered style spent more time typing and gazing at the computer during the visit. Physicians who used a mixed style shifted their attention and body language between their patients and the technology throughout the visit. Physicians who used the human-centered style spent the least amount of time typing and focused more on the patient. Conclusion A variety of EHR interaction styles may be effective in facilitating patient-centered care. However, potential drawbacks of each style exist and are discussed. Future research on this topic and design strategies for effective health information technology in primary care are also discussed. PMID:24009982

Additive interaction between heterogeneous environmental ...

EPA Pesticide Factsheets

BACKGROUND Environmental exposures often occur in tandem; however, epidemiological research often focuses on singular exposures. Statistical interactions among broad, well-characterized environmental domains have not yet been evaluated in association with health. We address this gap by conducting a county-level cross-sectional analysis of interactions between Environmental Quality Index (EQI) domain indices on preterm birth in the Unites States from 2000-2005.METHODS: The EQI, a county-level index constructed for the 2000-2005 time period, was constructed from five domain-specific indices (air, water, land, built and sociodemographic) using principal component analyses. County-level preterm birth rates (n=3141) were estimated using live births from the National Center for Health Statistics. Linear regression was used to estimate prevalence differences (PD) and 95% confidence intervals (CI) comparing worse environmental quality to the better quality for each model for a) each individual domain main effect b) the interaction contrast and c) the two main effects plus interaction effect (i.e. the “net effect”) to show departure from additive interaction for the all U.S counties. Analyses were also performed for subgroupings by four urban/rural strata. RESULTS: We found the suggestion of antagonistic interactions but no synergism, along with several purely additive (i.e., no interaction) associations. In the non-stratified model, we observed antagonistic interac

Cold-Flow Study of Low Frequency Pressure Instability in Hybrid Rocket Motors

NASA Technical Reports Server (NTRS)

Jenkins, Rhonald M.

1997-01-01

Past experience with hybrid rockets has shown that certain motor operating conditions are conducive to the formation of low frequency pressure oscillations, or flow instabilities, within the motor. Both past and present work in the hybrid propulsion community acknowledges deficiencies in the understanding of such behavior, though it seems probable that the answer lies in an interaction between the flow dynamics and the combustion heat release. Knowledge of the fundamental flow dynamics is essential to the basic understanding of the overall stability problem. A first step in this direction was a study conducted at NASA Marshall Space Flight Center (MSFC), centered around a laboratory-scale two dimensional water flow model of a hybrid rocket motor. Principal objectives included: (1) visualization of flow and measurement of flow velocity distributions: (2) assessment of the importance of shear layer instabilities in driving motor pressure oscillations; (3) determination of the interactions between flow induced shear layers with the mainstream flow, the secondary (wall) throughflow, and solid boundaries; (4) investigation of the interactions between wall flow oscillations and the mainstream flow pressure distribution.

Investigating student communities with network analysis of interactions in a physics learning center

NASA Astrophysics Data System (ADS)

Brewe, Eric; Kramer, Laird; Sawtelle, Vashti

2012-06-01

Developing a sense of community among students is one of the three pillars of an overall reform effort to increase participation in physics, and the sciences more broadly, at Florida International University. The emergence of a research and learning community, embedded within a course reform effort, has contributed to increased recruitment and retention of physics majors. We utilize social network analysis to quantify interactions in Florida International University’s Physics Learning Center (PLC) that support the development of academic and social integration. The tools of social network analysis allow us to visualize and quantify student interactions and characterize the roles of students within a social network. After providing a brief introduction to social network analysis, we use sequential multiple regression modeling to evaluate factors that contribute to participation in the learning community. Results of the sequential multiple regression indicate that the PLC learning community is an equitable environment as we find that gender and ethnicity are not significant predictors of participation in the PLC. We find that providing students space for collaboration provides a vital element in the formation of a supportive learning community.

A New Global Geomorphology?

NASA Technical Reports Server (NTRS)

Baker, V. R.

1985-01-01

Geomorphology is entering a new era of discovery and scientific excitement centered on expanding scales of concern in both time and space. The catalysts for this development include technological advances in global remote sensing systems, mathematical modeling, and the dating of geomorphic surfaces and processes. Even more important are new scientific questions centered on comparative planetary geomorphology, the interaction of tectonism with landscapes, the dynamics of late Cenozoic climatic changes, the influence of cataclysmic processes, the recognition of extremely ancient landforms, and the history of the world's hydrologic systems. These questions all involve feedback relationships with allied sciences that have recently yielded profound developments.

Interaction of classical platinum agents with the monomeric and dimeric Atox1 proteins: a molecular dynamics simulation study.

PubMed

Wang, Xiaolei; Li, Chaoqun; Wang, Yan; Chen, Guangju

2013-12-20

We carried out molecular dynamics simulations and free energy calculations for a series of binary and ternary models of the cisplatin, transplatin and oxaliplatin agents binding to a monomeric Atox1 protein and a dimeric Atox1 protein to investigate their interaction mechanisms. All three platinum agents could respectively combine with the monomeric Atox1 protein and the dimeric Atox1 protein to form a stable binary and ternary complex due to the covalent interaction of the platinum center with the Atox1 protein. The results suggested that the extra interaction from the oxaliplatin ligand-Atox1 protein interface increases its affinity only for the OxaliPt + Atox1 model. The binding of the oxaliplatin agent to the Atox1 protein might cause larger deformation of the protein than those of the cisplatin and transplatin agents due to the larger size of the oxaliplatin ligand. However, the extra interactions to facilitate the stabilities of the ternary CisPt + 2Atox1 and OxaliPt + 2Atox1 models come from the α1 helices and α2-β4 loops of the Atox1 protein-Atox1 protein interface due to the cis conformation of the platinum agents. The combinations of two Atox1 proteins in an asymmetric way in the three ternary models were analyzed. These investigations might provide detailed information for understanding the interaction mechanism of the platinum agents binding to the Atox1 protein in the cytoplasm.

Results of test MA22 in the NASA/LaRC 31-inch CFHT on an 0.010-scale model (32-0) of the space shuttle configuration 3 to determine RCS jet flow field interaction, volume 1. [wind tunnel tests for interactions of aerodynamic heating on jet flow

NASA Technical Reports Server (NTRS)

Kanipe, D. B.

1976-01-01

A wind tunnel test was conducted in the Langley Research Center 31-inch Continuous Flow Hypersonic Wind Tunnel from May 6, 1975 through June 3, 1975. The primary objectives of this test were the following: (1) to study the ability of the wind tunnel to repeat, on a run-to-run basis, data taken for identical configurations to determine if errors in repeatability could have a significant effect on jet interaction data, (2) to determine the effect of aerodynamic heating of the scale model on jet interaction, (3) to investigate the effects of elevon and body flap deflections on jet interaction, (4) to determine if the effects from jets fired separately along different axes can be added to equal the effects of the jets fired simultaneously (super position effects), (5) to study multiple jet effects, and (6) to investigate area ratio effects, i.e., the effect on jet interaction measurements of using wind tunnel nozzles with different area ratios in the same location. The model used in the test was a .010-scale model of the Space Shuttle Orbiter Configuration 3. The test was conducted at Mach 10.3 and a dynamic pressure of 150 psf. RCS chamber pressure was varied to simulate free flight dynamic pressures of 5, 7.5, 10, and 20 psf.

The effect of fenoterol stereochemistry on the β2 adrenergic receptor system: ligand directed chiral recognition

PubMed Central

Jozwiak, Krzysztof; Plazinska, Anita; Toll, Lawrence; Jimenez, Lucita; Woo, Anthony Yiu-Ho; Xiao, Rui-Ping; Wainer, Irving W.

2011-01-01

The β2 adrenergic receptor (β2-AR) is a model system for studying the ligand recognition process in G-protein coupled receptors. Fenoterol (FEN) is a β2-AR selective agonist that has two centers of chirality and exists as four stereoisomers. Radioligand binding studies determined that stereochemistry greatly influences the binding affinity. Subsequent Van’t Hoff analysis shows very different thermodynamics of binding depending on the stereoconfiguration of the molecule. The binding of (S,x’)-isomers is almost entirely enthalpy controlled whereas binding of (R,x’)-isomers is purely entropy driven. Stereochemistry of FEN molecule also affects the coupling of the receptor to different G proteins. In a rat cardiomyocyte contractility model, (R,R’)-FEN was shown to selectively activate Gs protein signaling while the (S,R’)- isomer activated both Gi and Gs protein. The overall data demonstrate that the chirality at the two chiral centers of the FEN molecule influences the magnitude of binding affinity, thermodynamics of local interactions within the binding site and the global mechanism of β2-AR activation. Differences in thermodynamic parameters and non-uniform G-protein coupling suggest a mechanism of chiral recognition in which observed enantioselectivities arise from the interaction of the (R,x’)-FEN stereoisomers with a different receptor conformation than the one with which the (S,x’)-isomer interacts. PMID:21618615

Effect of fenoterol stereochemistry on the β2 adrenergic receptor system: ligand-directed chiral recognition.

PubMed

Jozwiak, Krzysztof; Plazinska, Anita; Toll, Lawrence; Jimenez, Lucita; Woo, Anthony Yiu-Ho; Xiao, Rui-Ping; Wainer, Irving W

2011-01-01

The β(2) adrenergic receptor (β(2)-AR) is a model system for studying the ligand recognition process in G protein-coupled receptors. Fenoterol (FEN) is a β(2)-AR selective agonist that has two centers of chirality and exists as four stereoisomers. Radioligand binding studies determined that stereochemistry greatly influences the binding affinity. Subsequent Van't Hoff analysis shows very different thermodynamics of binding depending on the stereoconfiguration of the molecule. The binding of (S,x')-isomers is almost entirely enthalpy controlled whereas binding of (R,x')-isomers is purely entropy driven. Stereochemistry of FEN molecule also affects the coupling of the receptor to different G proteins. In a rat cardiomyocyte contractility model, (R,R')-FEN was shown to selectively activate G(s) protein signaling while the (S,R')-isomer activated both G(i) and G(s) protein. The overall data demonstrate that the chirality at the two chiral centers of the FEN molecule influences the magnitude of binding affinity, thermodynamics of local interactions within the binding site, and the global mechanism of β(2)-AR activation. Differences in thermodynamic parameters and nonuniform G-protein coupling suggest a mechanism of chiral recognition in which observed enantioselectivities arise from the interaction of the (R,x')-FEN stereoisomers with a different receptor conformation than the one with which the (S,x')-isomer interacts. Copyright © 2011 Wiley-Liss, Inc.

Closed-cell crystalline foams: self-assembling, resonant metamaterials.

PubMed

Spadoni, Alessandro; Höhler, Reinhard; Cohen-Addad, Sylvie; Dorodnitsyn, Vladimir

2014-04-01

Internal degrees of freedom and periodic structure are critical requirements in the design of acoustic/elastic metamaterials since they can give rise to extraordinary properties like negative effective mass and stiffness. However, they are challenging to realize in three dimensions. Closed-cell, crystalline foams are a particularly advantageous basis to develop metamaterials as they intrinsically have a complex microstructure, exhibiting internal resonances. Recently self-assembly techniques have been implemented to produce such foams: a Kelvin (body centered cubic) foam, a face centered cubic foam, and a Weaire-Phelan structure. Numerical models are employed to demonstrate that such foams are superanisotropic, selectively behaving as a fluid or a solid, pentamode solids as a result of fluid-structure interaction, in addition to having regimes characterized by film resonances and high density of states. Microstructural deformations obtained from numerical models allow the derivation of equivalent mechanical models.

The Trick Simulation Toolkit: A NASA/Opensource Framework for Running Time Based Physics Models

NASA Technical Reports Server (NTRS)

Penn, John M.

2016-01-01

The Trick Simulation Toolkit is a simulation development environment used to create high fidelity training and engineering simulations at the NASA Johnson Space Center and many other NASA facilities. Its purpose is to generate a simulation executable from a collection of user-supplied models and a simulation definition file. For each Trick-based simulation, Trick automatically provides job scheduling, numerical integration, the ability to write and restore human readable checkpoints, data recording, interactive variable manipulation, a run-time interpreter, and many other commonly needed capabilities. This allows simulation developers to concentrate on their domain expertise and the algorithms and equations of their models. Also included in Trick are tools for plotting recorded data and various other supporting utilities and libraries. Trick is written in C/C++ and Java and supports both Linux and MacOSX computer operating systems. This paper describes Trick's design and use at NASA Johnson Space Center.

Sgr A* as Source of the Positrons Observed in the Galactic Center Region

NASA Astrophysics Data System (ADS)

Jean, Pierre; Guessoum, Nidhal; Ferrière, Katia

2017-01-01

We explore the possibility that a substantial fraction of the positrons observed to annihilate in the central region of our Galaxy come from the supermassive black hole Sgr A* that lies at the center. This idea was proposed by several authors, but the propagation of the emitted positrons into the bulge and beyond remained a serious problem for models of the origin of GC positrons. We assume models of positron production with different energies. The propagation of positrons from their production site is followed in detail with Monte-Carlo simulations, taking into account the physical conditions of the propagation regions as well as various physical interactions. Using the known physics of positron annihilation in astrophysical environments, we calculate the properties of the annihilation emission (time evolution and spatial distribution) for the different models under consideration. We present the results of these simulations and the conclusions/constraints that can be inferred from them.

Efficient swimming of an assembly of rigid spheres at low Reynolds number.

PubMed

Felderhof, B U

2015-08-01

The swimming of an assembly of rigid spheres immersed in a viscous fluid of infinite extent is studied in low-Reynolds-number hydrodynamics. The instantaneous swimming velocity and rate of dissipation are expressed in terms of the time-dependent displacements of sphere centers about their collective motion. For small-amplitude swimming with periodically oscillating displacements, optimization of the mean swimming speed at given mean power leads to an eigenvalue problem involving a velocity matrix and a power matrix. The corresponding optimal stroke permits generalization to large-amplitude motion in a model of spheres with harmonic interactions and corresponding actuating forces. The method allows straightforward calculation of the swimming performance of structures modeled as assemblies of interacting rigid spheres. A model of three collinear spheres with motion along the common axis is studied as an example.

Tire-soil interaction model for turning (steered) tires

NASA Astrophysics Data System (ADS)

Karafiath, L. L.

1985-07-01

A review of the experimental information on the development of lateral forces on tires traveling at an angle to their center plane is presented and the usefulness of the consideration of the lateral forces for the development of an analytical model is evaluated. Major components of the lateral force have been identified as the forces required to balance the tractive force and the drawbar pull vectorially. These are the shear stresses developing in the contact area and the horizontal component of the normal stresses acting on the in-ground portion or the curved side walls of the tire. The tire-soil interaction model for steady state straight travel has been expanded to include the necessary algorithms for the calculation of these lateral forces. The pattern of tractive force-slip and longitudinal-lateral force relationships is in general agreement with experiments.

Assessing the extent of utilization of biopsychosocial model in doctor-patient interaction in public sector hospitals of a developing country.

PubMed

Nadir, Maha; Hamza, Muhammad; Mehmood, Nadir

2018-01-01

Biopsychosocial (BPS) model has been a mainstay in the ideal practice of modern medicine. It is attributed to improve patient care, compliance, and satisfaction and to reduce doctor-patient conflict. The study aimed to understand the importance given to BPS model while conducting routine doctor-patient interactions in public sector hospitals of a developing country where health resources are limited. The study was conducted in Rawalpindi, Pakistan. The study design is qualitative. Structured interviews were conducted from 44 patients from surgical and medical units of Benazir Bhutto Hospital and Holy Family Hospital. The questions were formulated based on patient-centered interviewing methods by reviewing the literature on BPS model. The analysis was done thematically using the software NVivo 11 for qualitative data. The study revealed four emerging themes: (1) Lack of doctor-patient rapport. (2) Utilization of a paternalistic approach during treatment. (3) Utilization of a reductionist biomedical approach during treatment. (4) Patients' concern with their improvement in health and doctor's demeanor. The study highlights the fact that BPS is not given considerable importance while taking routine medical history. This process remains doctor centered and paternalistic. However, patients are more concerned with their improvement in health rather than whether or not they are being provided informational care. Sequential studies will have to be conducted to determine whether this significantly affects patient care and compliance and whether BPS is a workable model in the healthcare system in the third world.

Tropical Convective Responses to Microphysical and Radiative Processes: A Sensitivity Study With a 2D Cloud Resolving Model

NASA Technical Reports Server (NTRS)

Li, Xiao-Fan; Sui, C.-H.; Lau, K.-M.; Tao, W.-K.

2004-01-01

Prognostic cloud schemes are increasingly used in weather and climate models in order to better treat cloud-radiation processes. Simplifications are often made in such schemes for computational efficiency, like the scheme being used in the National Centers for Environment Prediction models that excludes some microphysical processes and precipitation-radiation interaction. In this study, sensitivity tests with a 2D cloud resolving model are carried out to examine effects of the excluded microphysical processes and precipitation-radiation interaction on tropical thermodynamics and cloud properties. The model is integrated for 10 days with the imposed vertical velocity derived from the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment. The experiment excluding the depositional growth of snow from cloud ice shows anomalous growth of cloud ice and more than 20% increase of fractional cloud cover, indicating that the lack of the depositional snow growth causes unrealistically large mixing ratio of cloud ice. The experiment excluding the precipitation-radiation interaction displays a significant cooling and drying bias. The analysis of heat and moisture budgets shows that the simulation without the interaction produces more stable upper troposphere and more unstable mid and lower troposphere than does the simulation with the interaction. Thus, the suppressed growth of ice clouds in upper troposphere and stronger radiative cooling in mid and lower troposphere are responsible for the cooling bias, and less evaporation of rain associated with the large-scale subsidence induces the drying in mid and lower troposphere.

Structural and preliminary molecular dynamics studies of the Rhodobacter sphaeroides reaction center and its mutant form L(M196)H + H(M202)L

NASA Astrophysics Data System (ADS)

Klyashtorny, V. G.; Fufina, T. Yu.; Vasilieva, L. G.; Shuvalov, V. A.; Gabdulkhakov, A. G.

2014-07-01

Pigment-protein interactions are responsible for the high efficiency of the light-energy transfer and conversion in photosynthesis. The reaction center (RC) from the purple bacterium Rhodobacter sphaeroides is the most convenient model for studying the mechanisms of primary processes of photosynthesis. Site-directed mutagenesis can be used to study the effect of the protein environment of electron-transfer cofactors on the optical properties, stability, pigment composition, and functional activity of RC. The preliminary analysis of RC was performed by computer simulation of the amino acid substitutions L(M196)H + H(M202)L at the pigment-protein interface and by estimating the stability of the threedimensional structure of the mutant RC by the molecular dynamics method. The doubly mutated reaction center was overexpressed, purified, and crystallized. The three-dimensional structure of this mutant was determined by X-ray crystallography and compared with the molecular dynamics model.

Role of translational entropy in spatially inhomogeneous, coarse-grained models

NASA Astrophysics Data System (ADS)

Langenberg, Marcel; Jackson, Nicholas E.; de Pablo, Juan J.; Müller, Marcus

2018-03-01

Coarse-grained models of polymer and biomolecular systems have enabled the computational study of cooperative phenomena, e.g., self-assembly, by lumping multiple atomistic degrees of freedom along the backbone of a polymer, lipid, or DNA molecule into one effective coarse-grained interaction center. Such a coarse-graining strategy leaves the number of molecules unaltered. In order to treat the surrounding solvent or counterions on the same coarse-grained level of description, one can also stochastically group several of those small molecules into an effective, coarse-grained solvent bead or "fluid element." Such a procedure reduces the number of molecules, and we discuss how to compensate the concomitant loss of translational entropy by density-dependent interactions in spatially inhomogeneous systems.

ECM remodeling and its plasticity

NASA Astrophysics Data System (ADS)

Feng, Jingchen; Jones, Christopher A. R.; Cibula, Matthew; Mao, Xiaoming; Sander, Leonard M.; Levine, Herbert; Sun, Bo

The mechanical interactions between cells and Extracellular Matrix (ECM) are of great importance in many cellular processes. These interactions are reciprocal, i.e. contracting cells pull and reorganize the surrounding matrix, while the remodeled matrix feeds back to regulate cell activities. Recent experiments show in collagen gels with densely distributed cells, aligned fiber bundles are formed in the direction between neighboring cells. Fibers flow into the center region between contracting cell pairs in this process, which causes the concentration of fibers in the fiber bundles to become significantly enhanced. Using an extended lattice-based model, we show that viscoelasticity plays an essential role in ECM remodeling and contributes to the enhanced concentration in fiber bundles. We further characterize ECM plasticity within our model and verify our results with rheometer experiments.

Point charge representation of multicenter multipole moments in calculation of electrostatic properties

NASA Technical Reports Server (NTRS)

Sokalski, W. A.; Shibata, M.; Ornstein, R. L.; Rein, R.

1993-01-01

Distributed Point Charge Models (PCM) for CO, (H2O)2, and HS-SH molecules have been computed from analytical expressions using multi-center multipole moments. The point charges (set of charges including both atomic and non-atomic positions) exactly reproduce both molecular and segmental multipole moments, thus constituting an accurate representation of the local anisotropy of electrostatic properties. In contrast to other known point charge models, PCM can be used to calculate not only intermolecular, but also intramolecular interactions. Comparison of these results with more accurate calculations demonstrated that PCM can correctly represent both weak and strong (intramolecular) interactions, thus indicating the merit of extending PCM to obtain improved potentials for molecular mechanics and molecular dynamics computational methods.

A broadband multimedia TeleLearning system

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

Wang, Ruiping; Karmouch, A.

1996-12-31

In this paper we discuss a broadband multimedia TeleLearning system under development in the Multimedia Information Research Laboratory at the University of Ottawa. The system aims at providing a seamless environment for TeleLearning using the latest telecommunication and multimedia information processing technology. It basically consists of a media production center, a courseware author site, a courseware database, a courseware user site, and an on-line facilitator site. All these components are distributed over an ATM network and work together to offer a multimedia interactive courseware service. An MHEG-based model is exploited in designing the system architecture to achieve the real-time, interactive,more » and reusable information interchange through heterogeneous platforms. The system architecture, courseware processing strategies, courseware document models are presented.« less

Influence of the Pauli exclusion principle and the polarization of nuclei on the nuclear part of the interaction potential in the 40Ca +40Ca system

NASA Astrophysics Data System (ADS)

Nesterov, V. O.

2018-06-01

In the framework of the energy density method with the use of the wave function of the two-center shell model, the influence of the simultaneous account for the Pauli exclusion principle and the monopole and quadrupole polarizations of nuclei on the nuclear part of the potential of their interaction by the example of the 40Ca +40Ca system is considered. The calculations performed in the framework of the adiabatic approximation show that the consideration of the Pauli exclusion principle and the polarization of nuclei, especially the quadrupole one, essentially affects the nucleus-nucleus interaction potential.

Quantitative study of interactions between oxygen lone pair and aromatic rings: substituent effect and the importance of closeness of contact.

PubMed

Gung, Benjamin W; Zou, Yan; Xu, Zhigang; Amicangelo, Jay C; Irwin, Daniel G; Ma, Shengqian; Zhou, Hong-Cai

2008-01-18

Current models describe aromatic rings as polar groups based on the fact that benzene and hexafluorobenzene are known to have large and permanent quadrupole moments. This report describes a quantitative study of the interactions between oxygen lone pair and aromatic rings. We found that even electron-rich aromatic rings and oxygen lone pairs exhibit attractive interactions. Free energies of interactions are determined using the triptycene scaffold and the equilibrium constants were determined by low-temperature 1H NMR spectroscopy. An X-ray structure analysis for one of the model compounds confirms the close proximity between the oxygen and the center of the aromatic ring. Theoretical calculations at the MP2/aug-cc-pVTZ level corroborate the experimental results. The origin of attractive interactions was explored by using aromatic rings with a wide range of substituents. The interactions between an oxygen lone pair and an aromatic ring are attractive at van der Waals' distance even with electron-donating substituents. Electron-withdrawing groups increase the strength of the attractive interactions. The results from this study can be only partly rationalized by using the current models of aromatic system. Electrostatic-based models are consistent with the fact that stronger electron-withdrawing groups lead to stronger attractions, but fail to predict or rationalize the fact that weak attractions even exist between electron-rich arenes and oxygen lone pairs. The conclusion from this study is that aromatic rings cannot be treated as a simple quadrupolar functional group at van der Waals' distance. Dispersion forces and local dipole should also be considered.

Strategic re-design of team-based patient-focused health care services.

PubMed

Tahara, Denise C; Green, Richard P

2014-01-01

This paper proposes an organizational change process to prepare physicians and other health professionals for their new roles in patient-centered medical homes (PCMHs). It provides physician-centered tools, models, concepts, and the language to implement transformational patient-centered medical care. To improve care delivery, quality, and patient engagement, a systems approach to care is required. This paper examines a systems approach to patient care where all inputs that influence patient interactions and participation are considered in the design of health care delivery and follow-up treatment plans. Applying systems thinking, organizational change models, and team-building, we have examined the continuum of this change process from ideation through the diffusion of new methods and behaviors. PCMHs make compelling business sense. Studies have shown that the PCMH improves patient satisfaction, clinical outcomes and reduces underuse and overuse of medical services. Patient-centered care necessitates transitioning from an adversarial to a collaborative culture. It is a transformation process predicated on strong leadership able to align an organization toward a vision of patient-centered care, creating a collaborative culture committed to health-goal achievement. This paper proposes that the PCMH is a rigorous team-building transformational organizational change, a radical departure from the current hierarchical, silo-oriented, medical practice model. It requires that participants within and across health care organizations learn new skills and behaviors to achieve the anticipated quality and efficiency improvements. It is an innovative health care organization model of the future whose success is premised on teams supplanting the individual as the building block and unit of health care performance.

Design, synthesis and DNA interactions of a chimera between a platinum complex and an IHF mimicking peptide.

PubMed

Rao, Harita; Damian, Mariana S; Alshiekh, Alak; Elmroth, Sofi K C; Diederichsen, Ulf

2015-12-28

Conjugation of metal complexes with peptide scaffolds possessing high DNA binding affinity has shown to modulate their biological activities and to enhance their interaction with DNA. In this work, a platinum complex/peptide chimera was synthesized based on a model of the Integration Host Factor (IHF), an architectural protein possessing sequence specific DNA binding and bending abilities through its interaction with a minor groove. The model peptide consists of a cyclic unit resembling the minor grove binding subdomain of IHF, a positively charged lysine dendrimer for electrostatic interactions with the DNA phosphate backbone and a flexible glycine linker tethering the two units. A norvaline derived artificial amino acid was designed to contain a dimethylethylenediamine as a bidentate platinum chelating unit, and introduced into the IHF mimicking peptides. The interaction of the chimeric peptides with various DNA sequences was studied by utilizing the following experiments: thermal melting studies, agarose gel electrophoresis for plasmid DNA unwinding experiments, and native and denaturing gel electrophoresis to visualize non-covalent and covalent peptide-DNA adducts, respectively. By incorporation of the platinum metal center within the model peptide mimicking IHF we have attempted to improve its specificity and DNA targeting ability, particularly towards those sequences containing adjacent guanine residues.

Establishing access to technology: an evaluation and intervention model to increase the participation of children with cerebral palsy.

PubMed

McCarty, Elizabeth; Morress, Claire

2009-08-01

Children with a diagnosis of cerebral palsy often have significant physical limitations that prevent exploration and full participation in the environment. Assistive technology systems can provide opportunities for children with physical limitations to interact with their world, enabling play, communication, and daily living skills. Efficient access to and control of the technology is critical for successful use; however, establishing consistent access is often difficult because of the nature of the movement patterns exhibited by children with cerebral palsy. This article describes a 3-phase model of evaluation and intervention developed and used by Assistive Technology Services at the Aaron W. Perlman Center, Cincinnati Children's Hospital Medical Center, to establish successful access to technology systems in children with cerebral palsy.

Relationship of preschool special education outcomes to instructional practices and parent-child interaction.

PubMed

Mahoney, Gerald; Wheeden, C Abigail; Perales, Frida

2004-01-01

Developmental outcomes attained by children receiving preschool special education services in relationship to both the general instructional approach used by their teachers and their parents' style of interaction were examined. The sample included 70 children from 41 Early Childhood Special Education (ECSE) classrooms. The type of instructional model children received was determined by dividing the sample into three clusters based upon six global ratings of children's classroom environment: Choice; Cognitive Problem-Solving; Child-Initiated Learning; Developmental Match; Child-Centered Routines; and Rewards and Discipline Strategies. Based on this analysis, 27 children were classified as receiving developmental instruction; 15 didactic instruction; and 28 naturalistic instruction. Observations of parent-child interaction collected at the beginning and end of the year were classified along four dimensions using the Maternal Behavior Rating Scale: Responsiveness, Affect, Achievement Orientation and Directiveness. Results indicated that the kinds of experiences that children received varied significantly across the three instructional models. However, there were no significant differences in the impact of these instructional models on children's rate of development. Regression analyses indicated that children's rate of development at the end of intervention was significantly related to their parents' style of interaction but was unrelated to the type of instructional model they received.

Millimeter-Wave Time Resolved Studies of the Formation and Decay of CO^+

NASA Astrophysics Data System (ADS)

Oesterling, Lee; Herbst, Eric; de Lucia, Frank

1998-04-01

Since the rate constants for ion-molecule interactions are typically much larger than neutral-neutral interactions, understanding ion-molecule interactions is essential to interpreting radio astronomical spectra from interstellar clouds and modeling the processes which lead to the formation of stars in these regions. We have developed a cell which allows us to study ion-molecule interactions in gases at low temperatures and pressures by using an electron gun technique to create ions. By centering our millimeter-wave source on a rotational resonance and gating the electron beam on and off, we are able to study the time-dependent rotational state distribution of the ion during its formation and decay, and so learn about excitation and relaxation processes as functions of temperature, pressure, electron beam energy, and electron beam current.

Variables that influence BRAF mutation probability: A next-generation sequencing, non-interventional investigation of BRAFV600 mutation status in melanoma.

PubMed

Gaiser, Maria Rita; Skorokhod, Alexander; Gransheier, Diana; Weide, Benjamin; Koch, Winfried; Schif, Birgit; Enk, Alexander; Garbe, Claus; Bauer, Jürgen

2017-01-01

The incidence of melanoma, particularly in older patients, has steadily increased over the past few decades. Activating mutations of BRAF, the majority occurring in BRAFV600, are frequently detected in melanoma; however, the prognostic significance remains unclear. This study aimed to define the probability and distribution of BRAFV600 mutations, and the clinico-pathological factors that may affect BRAF mutation status, in patients with advanced melanoma using next-generation sequencing. This was a non-interventional, retrospective study of BRAF mutation testing at two German centers, in Heidelberg and Tübingen. Archival tumor samples from patients with histologically confirmed melanoma (stage IIIB, IIIC, IV) were analyzed using PCR amplification and deep sequencing. Clinical, histological, and mutation data were collected. The statistical influence of patient- and tumor-related characteristics on BRAFV600 mutation status was assessed using multiple logistic regression (MLR) and a prediction profiler. BRAFV600 mutation status was assessed in 453 samples. Mutations were detected in 57.6% of patients (n = 261), with 48.1% (n = 102) at the Heidelberg site and 66.0% (n = 159) at the Tübingen site. The decreasing influence of increasing age on mutation probability was quantified. A main effects MLR model identified age (p = 0.0001), center (p = 0.0004), and melanoma subtype (p = 0.014) as significantly influencing BRAFV600 mutation probability; ultraviolet (UV) exposure showed a statistical trend (p = 0.1419). An interaction model of age versus other variables showed that center (p<0.0001) and melanoma subtype (p = 0.0038) significantly influenced BRAF mutation probability; age had a statistically significant effect only as part of an interaction with both UV exposure (p = 0.0110) and melanoma subtype (p = 0.0134). This exploratory study highlights that testing center, melanoma subtype, and age in combination with UV exposure and melanoma subtype significantly influence BRAFV600 mutation probability in patients with melanoma. Further validation of this model, in terms of reproducibility and broader relevance, is required.

Nanoscale Interparticle Distance within Dimers in Solution Measured by Light Scattering

PubMed Central

2017-01-01

We demonstrate a novel approach to quantify the interparticle distance in colloidal dimers using Mie scattering. The interparticle distance is varied in a controlled way by changing the ionic strength of the solution and the magnetic attraction between the particles. The measured scaling behavior is interpreted using an energy–distance model that includes the repulsive electrostatic and attractive magnetic interactions. The center-to-center distances of particles with a 525 nm radius can be determined with a root-mean-square accuracy of 12 nm. The data show that the center-to-center distance is larger by 83 nm compared to perfect spheres. The underlying distance offset can be attributed to repulsion by charged protrusions caused by particle surface roughness. The measurement method accurately quantifies interparticle distances that can be used to study cluster formation and colloid aggregation in complex systems, e.g., in biosensing applications. PMID:29183122

Electrical detection of electron-spin-echo envelope modulations in thin-film silicon solar cells

NASA Astrophysics Data System (ADS)

Fehr, M.; Behrends, J.; Haas, S.; Rech, B.; Lips, K.; Schnegg, A.

2011-11-01

Electrically detected electron-spin-echo envelope modulations (ED-ESEEM) were employed to detect hyperfine interactions between nuclear spins and paramagnetic sites, determining spin-dependent transport processes in multilayer thin-film microcrystalline silicon solar cells. Electrical detection in combination with a modified Hahn-echo sequence was used to measure echo modulations induced by 29Si, 31P, and 1H nuclei weakly coupled to electron spins of paramagnetic sites in the amorphous and microcrystalline solar cell layers. In the case of CE centers in the μc-Si:H i-layer, the absence of 1H ESEEM modulations indicates that the adjacencies of CE centers are depleted from hydrogen atoms. On the basis of this result, we discuss several models for the microscopic origin of the CE center and conclusively assign those centers to coherent twin boundaries inside of crystalline grains in μc-Si:H.

AND YET IT MOVES: THE DANGERS OF ARTIFICIALLY FIXING THE MILKY WAY CENTER OF MASS IN THE PRESENCE OF A MASSIVE LARGE MAGELLANIC CLOUD

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

Gómez, Facundo A.; O’Shea, Brian W.; Besla, Gurtina

2015-04-01

Motivated by recent studies suggesting that the Large Magellanic Cloud (LMC) could be significantly more massive than previously thought, we explore whether the approximation of an inertial Galactocentric reference frame is still valid in the presence of such a massive LMC. We find that previous estimates of the LMC’s orbital period and apocentric distance derived assuming a fixed Milky Way (MW) are significantly shortened for models where the MW is allowed to move freely in response to the gravitational pull of the LMC. Holding other parameters fixed, the fraction of models favoring first infall is reduced. Due to this interaction,more » the MW center of mass within the inner 50 kpc can be significantly displaced in phase-space in a very short period of time that ranges from 0.3 to 0.5 Gyr by as much as 30 kpc and 75 km s{sup −1}. Furthermore, we show that the gravitational pull of the LMC and response of the MW are likely to significantly affect the orbit and phase space distribution of tidal debris from the Sagittarius dwarf galaxy (Sgr). Such effects are larger than previous estimates based on the torque of the LMC alone. As a result, Sgr deposits debris in regions of the sky that are not aligned with the present-day Sgr orbital plane. In addition, we find that properly accounting for the movement of the MW around its common center of mass with the LMC significantly modifies the angular distance between apocenters and tilts its orbital pole, alleviating tensions between previous models and observations. While these models are preliminary in nature, they highlight the central importance of accounting for the mutual gravitational interaction between the MW and LMC when modeling the kinematics of objects in the MW and Local Group.« less

Three-dimensional local grid refinement for block-centered finite-difference groundwater models using iteratively coupled shared nodes: A new method of interpolation and analysis of errors

USGS Publications Warehouse

Mehl, S.; Hill, M.C.

2004-01-01

This paper describes work that extends to three dimensions the two-dimensional local-grid refinement method for block-centered finite-difference groundwater models of Mehl and Hill [Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes. Adv Water Resour 2002;25(5):497-511]. In this approach, the (parent) finite-difference grid is discretized more finely within a (child) sub-region. The grid refinement method sequentially solves each grid and uses specified flux (parent) and specified head (child) boundary conditions to couple the grids. Iteration achieves convergence between heads and fluxes of both grids. Of most concern is how to interpolate heads onto the boundary of the child grid such that the physics of the parent-grid flow is retained in three dimensions. We develop a new two-step, "cage-shell" interpolation method based on the solution of the flow equation on the boundary of the child between nodes shared with the parent grid. Error analysis using a test case indicates that the shared-node local grid refinement method with cage-shell boundary head interpolation is accurate and robust, and the resulting code is used to investigate three-dimensional local grid refinement of stream-aquifer interactions. Results reveal that (1) the parent and child grids interact to shift the true head and flux solution to a different solution where the heads and fluxes of both grids are in equilibrium, (2) the locally refined model provided a solution for both heads and fluxes in the region of the refinement that was more accurate than a model without refinement only if iterations are performed so that both heads and fluxes are in equilibrium, and (3) the accuracy of the coupling is limited by the parent-grid size - A coarse parent grid limits correct representation of the hydraulics in the feedback from the child grid.

ODISEES Data Portal Announcement

Atmospheric Science Data Center

2015-11-13

... larger image The Ontology-Driven Interactive Search Environment for Earth Science, developed at the Atmospheric Science Data Center ... The Ontology-Driven Interactive Search Environment for Earth Science, developed at the Atmospheric Science Data Center ...

Analytical display design for flight tasks conducted under instrument meteorological conditions. [human factors engineering of pilot performance for display device design in instrument landing systems

NASA Technical Reports Server (NTRS)

Hess, R. A.

1976-01-01

Paramount to proper utilization of electronic displays is a method for determining pilot-centered display requirements. Display design should be viewed fundamentally as a guidance and control problem which has interactions with the designer's knowledge of human psychomotor activity. From this standpoint, reliable analytical models of human pilots as information processors and controllers can provide valuable insight into the display design process. A relatively straightforward, nearly algorithmic procedure for deriving model-based, pilot-centered display requirements was developed and is presented. The optimal or control theoretic pilot model serves as the backbone of the design methodology, which is specifically directed toward the synthesis of head-down, electronic, cockpit display formats. Some novel applications of the optimal pilot model are discussed. An analytical design example is offered which defines a format for the electronic display to be used in a UH-1H helicopter in a landing approach task involving longitudinal and lateral degrees of freedom.

Neutron Environment Calculations for Low Earth Orbit

NASA Technical Reports Server (NTRS)

Clowdsley, M. S.; Wilson, J. W.; Shinn, J. L.; Badavi, F. F.; Heinbockel, J. H.; Atwell, W.

2001-01-01

The long term exposure of astronauts on the developing International Space Station (ISS) requires an accurate knowledge of the internal exposure environment for human risk assessment and other onboard processes. The natural environment is moderated by the solar wind, which varies over the solar cycle. The HZETRN high charge and energy transport code developed at NASA Langley Research Center can be used to evaluate the neutron environment on ISS. A time dependent model for the ambient environment in low earth orbit is used. This model includes GCR radiation moderated by the Earth's magnetic field, trapped protons, and a recently completed model of the albedo neutron environment formed through the interaction of galactic cosmic rays with the Earth's atmosphere. Using this code, the neutron environments for space shuttle missions were calculated and comparisons were made to measurements by the Johnson Space Center with onboard detectors. The models discussed herein are being developed to evaluate the natural and induced environment data for the Intelligence Synthesis Environment Project and eventual use in spacecraft optimization.

Provider Communication and Role Modeling Related to Patients' Perceptions and Use of a Federally Qualified Health Center-based Farmers' Market

PubMed Central

Friedman, Daniela B.; Freedman, Darcy A.; Choi, Seul Ki; Anadu, Edith C.; Brandt, Heather M.; Carvalho, Natalia; Hurley, Thomas G.; Young, Vicki M.; Hebert, James R.

2013-01-01

Farmers’ markets have the potential to improve the health of underserved communities, shape people’s perceptions, values, and behaviors about healthy eating, and serve as a social space for both community members and vendors. This study explored the influence of health care provider communication and role modeling for diabetic patients within the context of a farmers’ market located at a federally qualified health center (FQHC). Although provider communication about diet decreased over time, communication strategies included: providing patients with “prescriptions” and vouchers for market purchases; educating patients about diet; and modeling healthy purchases. Data from patient interviews and provider surveys revealed that patients enjoyed social aspects of the market including interactions with their health care provider, and providers distributed prescriptions and vouchers to patients, shopped at the market, and believed the market had potential to improve the health of FHQC staff and patients. Provider modeling of healthy behaviors may influence patients’ food-related perceptions and dietary behaviors. PMID:23986503

Static and Dynamic Flow Visualization Studies of Two Double-Delta Wing Models at High Angles of Attack

DTIC Science & Technology

1992-03-01

body, ft U.= free-stream velocity, ft/sec In the case of a wing pitching about its mid-chord location, it can be interpreted as the ratio of the...Over Moderately Swept Delta Wings," HTP -5 Workshop On Vortical Flow Breakdown and Structural Interactions, NASA Langley Research Center, August 15-16...January 6- 9,1992/Reno,Nevada. 18. User’s Manual , Flow Visualization Water Tunnel Operation for Model 1520, Eidelic International, Inc., Torrance

Solid Modeling Aerospace Research Tool (SMART) user's guide, version 2.0

NASA Technical Reports Server (NTRS)

Mcmillin, Mark L.; Spangler, Jan L.; Dahmen, Stephen M.; Rehder, John J.

1993-01-01

The Solid Modeling Aerospace Research Tool (SMART) software package is used in the conceptual design of aerospace vehicles. It provides a highly interactive and dynamic capability for generating geometries with Bezier cubic patches. Features include automatic generation of commonly used aerospace constructs (e.g., wings and multilobed tanks); cross-section skinning; wireframe and shaded presentation; area, volume, inertia, and center-of-gravity calculations; and interfaces to various aerodynamic and structural analysis programs. A comprehensive description of SMART and how to use it is provided.

Brownian dynamics simulations of a flexible polymer chain which includes continuous resistance and multibody hydrodynamic interactions

NASA Astrophysics Data System (ADS)

Butler, Jason E.; Shaqfeh, Eric S. G.

2005-01-01

Using methods adapted from the simulation of suspension dynamics, we have developed a Brownian dynamics algorithm with multibody hydrodynamic interactions for simulating the dynamics of polymer molecules. The polymer molecule is modeled as a chain composed of a series of inextensible, rigid rods with constraints at each joint to ensure continuity of the chain. The linear and rotational velocities of each segment of the polymer chain are described by the slender-body theory of Batchelor [J. Fluid Mech. 44, 419 (1970)]. To include hydrodynamic interactions between the segments of the chain, the line distribution of forces on each segment is approximated by making a Legendre polynomial expansion of the disturbance velocity on the segment, where the first two terms of the expansion are retained in the calculation. Thus, the resulting linear force distribution is specified by a center of mass force, couple, and stresslet on each segment. This method for calculating the hydrodynamic interactions has been successfully used to simulate the dynamics of noncolloidal suspensions of rigid fibers [O. G. Harlen, R. R. Sundararajakumar, and D. L. Koch, J. Fluid Mech. 388, 355 (1999); J. E. Butler and E. S. G. Shaqfeh, J. Fluid Mech. 468, 204 (2002)]. The longest relaxation time and center of mass diffusivity are among the quantities calculated with the simulation technique. Comparisons are made for different levels of approximation of the hydrodynamic interactions, including multibody interactions, two-body interactions, and the "freely draining" case with no interactions. For the short polymer chains studied in this paper, the results indicate a difference in the apparent scaling of diffusivity with polymer length for the multibody versus two-body level of approximation for the hydrodynamic interactions.

Brownian dynamics simulations of a flexible polymer chain which includes continuous resistance and multibody hydrodynamic interactions.

PubMed

Butler, Jason E; Shaqfeh, Eric S G

2005-01-01

Using methods adapted from the simulation of suspension dynamics, we have developed a Brownian dynamics algorithm with multibody hydrodynamic interactions for simulating the dynamics of polymer molecules. The polymer molecule is modeled as a chain composed of a series of inextensible, rigid rods with constraints at each joint to ensure continuity of the chain. The linear and rotational velocities of each segment of the polymer chain are described by the slender-body theory of Batchelor [J. Fluid Mech. 44, 419 (1970)]. To include hydrodynamic interactions between the segments of the chain, the line distribution of forces on each segment is approximated by making a Legendre polynomial expansion of the disturbance velocity on the segment, where the first two terms of the expansion are retained in the calculation. Thus, the resulting linear force distribution is specified by a center of mass force, couple, and stresslet on each segment. This method for calculating the hydrodynamic interactions has been successfully used to simulate the dynamics of noncolloidal suspensions of rigid fibers [O. G. Harlen, R. R. Sundararajakumar, and D. L. Koch, J. Fluid Mech. 388, 355 (1999); J. E. Butler and E. S. G. Shaqfeh, J. Fluid Mech. 468, 204 (2002)]. The longest relaxation time and center of mass diffusivity are among the quantities calculated with the simulation technique. Comparisons are made for different levels of approximation of the hydrodynamic interactions, including multibody interactions, two-body interactions, and the "freely draining" case with no interactions. For the short polymer chains studied in this paper, the results indicate a difference in the apparent scaling of diffusivity with polymer length for the multibody versus two-body level of approximation for the hydrodynamic interactions. (c) 2005 American Institute of Physics.

Reevaluating the two-representation model of numerical magnitude processing.

PubMed

Jiang, Ting; Zhang, Wenfeng; Wen, Wen; Zhu, Haiting; Du, Han; Zhu, Xiangru; Gao, Xuefei; Zhang, Hongchuan; Dong, Qi; Chen, Chuansheng

2016-01-01

One debate in mathematical cognition centers on the single-representation model versus the two-representation model. Using an improved number Stroop paradigm (i.e., systematically manipulating physical size distance), in the present study we tested the predictions of the two models for number magnitude processing. The results supported the single-representation model and, more importantly, explained how a design problem (failure to manipulate physical size distance) and an analytical problem (failure to consider the interaction between congruity and task-irrelevant numerical distance) might have contributed to the evidence used to support the two-representation model. This study, therefore, can help settle the debate between the single-representation and two-representation models.

On the time-splitting scheme used in the Princeton Ocean Model

NASA Astrophysics Data System (ADS)

Kamenkovich, V. M.; Nechaev, D. A.

2009-05-01

The analysis of the time-splitting procedure implemented in the Princeton Ocean Model (POM) is presented. The time-splitting procedure uses different time steps to describe the evolution of interacting fast and slow propagating modes. In the general case the exact separation of the fast and slow modes is not possible. The main idea of the analyzed procedure is to split the system of primitive equations into two systems of equations for interacting external and internal modes. By definition, the internal mode varies slowly and the crux of the problem is to determine the proper filter, which excludes the fast component of the external mode variables in the relevant equations. The objective of this paper is to examine properties of the POM time-splitting procedure applied to equations governing the simplest linear non-rotating two-layer model of constant depth. The simplicity of the model makes it possible to study these properties analytically. First, the time-split system of differential equations is examined for two types of the determination of the slow component based on an asymptotic approach or time-averaging. Second, the differential-difference scheme is developed and some criteria of its stability are discussed for centered, forward, or backward time-averaging of the external mode variables. Finally, the stability of the POM time-splitting schemes with centered and forward time-averaging is analyzed. The effect of the Asselin filter on solutions of the considered schemes is studied. It is assumed that questions arising in the analysis of the simplest model are inherent in the general model as well.

Bayesian hierarchical model of ceftriaxone resistance proportions among Salmonella serotype Heidelberg infections.

PubMed

Gu, Weidong; Medalla, Felicita; Hoekstra, Robert M

2018-02-01

The National Antimicrobial Resistance Monitoring System (NARMS) at the Centers for Disease Control and Prevention tracks resistance among Salmonella infections. The annual number of Salmonella isolates of a particular serotype from states may be small, making direct estimation of resistance proportions unreliable. We developed a Bayesian hierarchical model to improve estimation by borrowing strength from relevant sampling units. We illustrate the models with different specifications of spatio-temporal interaction using 2004-2013 NARMS data for ceftriaxone-resistant Salmonella serotype Heidelberg. Our results show that Bayesian estimates of resistance proportions were smoother than observed values, and the difference between predicted and observed proportions was inversely related to the number of submitted isolates. The model with interaction allowed for tracking of annual changes in resistance proportions at the state level. We demonstrated that Bayesian hierarchical models provide a useful tool to examine spatio-temporal patterns of small sample size such as those found in NARMS. Published by Elsevier Ltd.

Numerical Modeling of Fluid Flow, Heat Transfer and Arc-Melt Interaction in Tungsten Inert Gas Welding

NASA Astrophysics Data System (ADS)

Li, Linmin; Li, Baokuan; Liu, Lichao; Motoyama, Yuichi

2017-04-01

The present work develops a multi-region dynamic coupling model for fluid flow, heat transfer and arc-melt interaction in tungsten inert gas (TIG) welding using the dynamic mesh technique. The arc-weld pool unified model is developed on basis of magnetohydrodynamic (MHD) equations and the interface is tracked using the dynamic mesh method. The numerical model for arc is firstly validated by comparing the calculated temperature profiles and essential results with the former experimental data. For weld pool convection solution, the drag, Marangoni, buoyancy and electromagnetic forces are separately validated, and then taken into account. Moreover, the model considering interface deformation is adopted in a stationary TIG welding process with SUS304 stainless steel and the effect of interface deformation is investigated. The depression of weld pool center and the lifting of pool periphery are both predicted. The results show that the weld pool shape calculated with considering the interface deformation is more accurate.

Bianchi IX dynamics in bouncing cosmologies: homoclinic chaos and the BKL conjecture

NASA Astrophysics Data System (ADS)

Maier, Rodrigo; Damião Soares, Ivano; Valentino Tonini, Eduardo

2015-12-01

We examine the dynamics of a Bianchi IX model with three scale factors on a 4-dim Lorentzian brane embedded in a 5-dim conformally flat empty bulk with a timelike extra dimension. The matter content is a pressureless perfect fluid restricted to the brane, with the embedding consistently satisfying the Gauss-Codazzi equations. The 4-dim Einstein equations on the brane reduce to a 6-dim Hamiltonian dynamical system with additional terms (due to the bulk-brane interaction) that avoid the singularity and implement nonsingular bounces in the model. We examine the complex Bianchi IX dynamics in its approach to the neighborhood of the bounce which replaces the cosmological singularity of general relativity. The phase space of the model presents (i) two critical points (a saddle-center-center and a center-center-center) in a finite region of phase space, (ii) two asymptotic de Sitter critical points at infinity, one acting as an attractor to late-time acceleration and (iii) a 2-dim invariant plane, which together organize the dynamics of the phase space. The saddle-center-center engenders in the phase space the topology of stable and unstable 4-dim cylinders R × S 3, where R is a saddle direction and S 3 is the center manifold of unstable periodic orbits, the latter being the nonlinear extension of the center-center sector. By a proper canonical transformation the degrees of freedom of the dynamics are separated into one degree connected with the expansion/contraction of the scales of the model, and two rotational degrees of freedom associated with the center manifold S 3. The typical dynamical flow is thus an oscillatory mode about the orbits of the invariant plane. The stable and unstable cylinders are spanned by oscillatory orbits about the separatrix towards the bounce, leading to the homoclinic transversal intersection of the cylinders, as shown numerically in two distinct simulations. The homoclinic intersection manifold has the topology of R × S 2 consisting of homoclinic orbits biasymptotic to the center manifold S 3. This behavior defines a chaotic saddle associated with S 3, indicating that the intersection points of the cylinders have the nature of a Cantor set with compact support S 2. This is an invariant signature of chaos in the model. We discuss the connection between these properties of the dynamics, namely the oscillatory approach to the bounce together with its chaotic behavior, and analogous features present in the BKL conjecture in general relativity.

Mary S. Easton Center of Alzheimer's Disease Research at UCLA: advancing the therapeutic imperative.

PubMed

Cummings, Jeffrey L; Ringman, John; Metz, Karen

2010-01-01

The Mary S. Easton Center for Alzheimer's Disease Research (UCLA-Easton Alzheimer's Center) is committed to the "therapeutic imperative" and is devoted to finding new treatments for Alzheimer's disease (AD) and to developing technologies (biomarkers) to advance that goal. The UCLA-Easton Alzheimer's Center has a continuum of research and research-related activities including basic/foundational studies of peptide interactions; translational studies in transgenic animals and other animal models of AD; clinical research to define the phenotype of AD, characterize familial AD, develop biomarkers, and advance clinical trials; health services and outcomes research; and active education, dissemination, and recruitment activities. The UCLAEaston Alzheimer's Center is supported by the National Institutes on Aging, the State of California, and generous donors who share our commitment to developing new therapies for AD. The naming donor (Jim Easton) provided substantial funds to endow the center and to support projects in AD drug discovery and biomarker development. The Sidell-Kagan Foundation supports the Katherine and Benjamin Kagan Alzheimer's Treatment Development Program, and the Deane F. Johnson Alzheimer's Research Foundation supports the Deane F. Johnson Center for Neurotherapeutics at UCLA. The John Douglas French Alzheimer's Research Foundation provides grants to junior investigators in critical periods of their academic development. The UCLA-Easton Alzheimer's Center partners with community organizations including the Alzheimer's Association California Southland Chapter and the Leeza Gibbons memory Foundation. Collaboration with pharmaceutical companies, biotechnology companies, and device companies is critical to developing new therapeutics for AD and these collaborations are embraced in the mission of the UCLA-Easton Alzheimer's Center. The Center supports excellent senior 3 investigators and serves as an incubator for new scientists, agents, models, technologies and concepts that will significantly influence the future of AD treatment and AD research.

Impact of Intervention to Improve Nursing Home Resident-Staff Interactions and Engagement.

PubMed

Hartmann, Christine W; Mills, Whitney L; Pimentel, Camilla B; Palmer, Jennifer A; Allen, Rebecca S; Zhao, Shibei; Wewiorski, Nancy J; Sullivan, Jennifer L; Dillon, Kristen; Clark, Valerie; Berlowitz, Dan R; Snow, Andrea Lynn

2018-04-30

For nursing home residents, positive interactions with staff and engagement in daily life contribute meaningfully to quality of life. We sought to improve these aspects of person-centered care in an opportunistic snowball sample of six Veterans Health Administration nursing homes (e.g., Community Living Centers-CLCs) using an intervention that targeted staff behavior change, focusing on improving interactions between residents and staff and thereby ultimately aiming to improve resident engagement. We grounded this mixed-methods study in the Capability, Opportunity, Motivation, Behavior (COM-B) model of behavior change. We implemented the intervention by (a) using a set of evidence-based practices for implementing quality improvement and (b) combining primarily CLC-based staff facilitation with some researcher-led facilitation. Validated resident and staff surveys and structured observations collected pre and post intervention, as well as semi-structured staff interviews conducted post intervention, helped assess intervention success. Sixty-two CLC residents and 308 staff members responded to the surveys. Researchers conducted 1,490 discrete observations. Intervention implementation was associated with increased staff communication with residents during the provision of direct care and decreased negative staff interactions with residents. In the 66 interviews, staff consistently credited the intervention with helping them (a) develop awareness of the importance of identifying opportunities for engagement and (b) act to improve the quality of interactions between residents and staff. The intervention proved feasible and influenced staff to make simple enhancements to their behaviors that improved resident-staff interactions and staff-assessed resident engagement.

Drug Research

NASA Technical Reports Server (NTRS)

1989-01-01

NBOD2, a program developed at Goddard Space Flight Center to solve equations of motion coupled N-body systems is used by E.I. DuPont de Nemours & Co. to model potential drugs as a series of elements. The program analyses the vibrational and static motions of independent components in drugs. Information generated from this process is used to design specific drugs to interact with enzymes in designated ways.

Walking on a Line: A Motor Paradigm Using Rotation and Reflection Symmetry to Study Mental Body Transformations

ERIC Educational Resources Information Center

Thirioux, Berangere; Jorland, Gerard; Bret, Michel; Tramus, Marie-Helene; Berthoz, Alain

2009-01-01

Researchers have recently reintroduced the own-body in the center of the social interaction theory. From the discovery of the mirror neurons in the ventral premotor cortex of the monkey's brain, a human "embodied" model of interindividual relationship based on simulation processes has been advanced, according to which we tend to embody…

Attitude stabilization of a spacecraft equipped with large electrostatic protection screens

NASA Astrophysics Data System (ADS)

Nikitin, D. Yu.; Tikhonov, A. A.

2018-05-01

A satellite with a system of three electrostatic radiation protection (ERP) screens is under consideration. The screens are constructed as electrostatically charged toroidal shields with characteristic size of order equal to 100 m. The interaction of electric charge with the Earth's magnetic field (EMF) give rise to the Lorentz torque acting upon a satellite attitude motion. As the sizes of ERP system are large, we derive the Lorentz torque taking into account the complex form of ERP screens and gradient of the EMF in the screen volume. It is assumed that the satellite center of charge coincides with the satellite mass center. The EMF is modeled by the straight magnetic dipole. In the paper we investigate the usage of Lorentz torque for passive attitude stabilization for satellite in a circular equatorial orbit. Mathematical model for attitude dynamics of a satellite equipped with ERP interacting with the EMF is derived and first integral of corresponding differential equations is constructed. The straight equilibrium position of the satellite in the orbital frame is found. Sufficient conditions for stability of satellite equilibrium position are constructed with the use of the first integral. The gravity gradient torque is taken into account. The satellite equilibrium stability domain is constructed.

Institutionalization in Action: Interactive Science Center Interactivity and Materiality from the Family Perspective

ERIC Educational Resources Information Center

Crain, Rhiannon Lorraine

2009-01-01

Interactive science centers are unique players in the science education community, but their positioning as both authorities on science and providers of "free choice" learning presents learning researchers with a problematic contradiction rooted in the complexities of trying to be both "scientific" and "education" organizations. Using insight from…

Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High-energy Emission from the Inner 2°×1° of the Galactic Center

NASA Astrophysics Data System (ADS)

Yusef-Zadeh, F.; Hewitt, J. W.; Wardle, M.; Tatischeff, V.; Roberts, D. A.; Cotton, W.; Uchiyama, H.; Nobukawa, M.; Tsuru, T. G.; Heinke, C.; Royster, M.

2013-01-01

The high-energy activity in the inner few degrees of the Galactic center is traced by diffuse radio, X-ray, and γ-ray emission. The physical relationship between different components of diffuse gas emitting at multiple wavelengths is a focus of this work. We first present radio continuum observations using the Green Bank Telescope and model the nonthermal spectrum in terms of a broken power-law distribution of ~GeV electrons emitting synchrotron radiation. We show that the emission detected by Fermi is primarily due to nonthermal bremsstrahlung produced by the population of synchrotron emitting electrons in the GeV energy range interacting with neutral gas. The extrapolation of the electron population measured from radio data to low and high energies can also explain the origin of Fe I 6.4 keV line and diffuse TeV emission, as observed with Suzaku, XMM-Newton, Chandra, and the H.E.S.S. observatories. The inferred physical quantities from modeling multiwavelength emission in the context of bremsstrahlung emission from the inner ~300 × 120 pc of the Galactic center are constrained to have the cosmic-ray ionization rate ~1-10 × 10-15 s-1, molecular gas heating rate elevating the gas temperature to 75-200 K, fractional ionization of molecular gas 10-6-10-5, large-scale magnetic field 10-20 μG, the density of diffuse and dense molecular gas ~100 and ~103 cm-3 over 300 pc and 50 pc path lengths, and the variability of Fe I Kα 6.4 keV line emission on yearly timescales. Important implications of our study are that GeV electrons emitting in radio can explain the GeV γ-rays detected by Fermi and that the cosmic-ray irradiation model, like the model of the X-ray irradiation triggered by past activity of Sgr A*, can also explain the origin of the variable 6.4 keV emission from Galactic center molecular clouds.

INTERACTING COSMIC RAYS WITH MOLECULAR CLOUDS: A BREMSSTRAHLUNG ORIGIN OF DIFFUSE HIGH-ENERGY EMISSION FROM THE INNER 2 Degree-Sign Multiplication-Sign 1 Degree-Sign OF THE GALACTIC CENTER

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

Yusef-Zadeh, F.; Roberts, D. A.; Royster, M.

2013-01-01

The high-energy activity in the inner few degrees of the Galactic center is traced by diffuse radio, X-ray, and {gamma}-ray emission. The physical relationship between different components of diffuse gas emitting at multiple wavelengths is a focus of this work. We first present radio continuum observations using the Green Bank Telescope and model the nonthermal spectrum in terms of a broken power-law distribution of {approx}GeV electrons emitting synchrotron radiation. We show that the emission detected by Fermi is primarily due to nonthermal bremsstrahlung produced by the population of synchrotron emitting electrons in the GeV energy range interacting with neutral gas.more » The extrapolation of the electron population measured from radio data to low and high energies can also explain the origin of Fe I 6.4 keV line and diffuse TeV emission, as observed with Suzaku, XMM-Newton, Chandra, and the H.E.S.S. observatories. The inferred physical quantities from modeling multiwavelength emission in the context of bremsstrahlung emission from the inner {approx}300 Multiplication-Sign 120 pc of the Galactic center are constrained to have the cosmic-ray ionization rate {approx}1-10 Multiplication-Sign 10{sup -15} s{sup -1}, molecular gas heating rate elevating the gas temperature to 75-200 K, fractional ionization of molecular gas 10{sup -6}-10{sup -5}, large-scale magnetic field 10-20 {mu}G, the density of diffuse and dense molecular gas {approx}100 and {approx}10{sup 3} cm{sup -3} over 300 pc and 50 pc path lengths, and the variability of Fe I K{alpha} 6.4 keV line emission on yearly timescales. Important implications of our study are that GeV electrons emitting in radio can explain the GeV {gamma}-rays detected by Fermi and that the cosmic-ray irradiation model, like the model of the X-ray irradiation triggered by past activity of Sgr A*, can also explain the origin of the variable 6.4 keV emission from Galactic center molecular clouds.« less

[Tumor Data Interacted System Design Based on Grid Platform].

PubMed

Liu, Ying; Cao, Jiaji; Zhang, Haowei; Zhang, Ke

2016-06-01

In order to satisfy demands of massive and heterogeneous tumor clinical data processing and the multi-center collaborative diagnosis and treatment for tumor diseases,a Tumor Data Interacted System(TDIS)was established based on grid platform,so that an implementing virtualization platform of tumor diagnosis service was realized,sharing tumor information in real time and carrying on standardized management.The system adopts Globus Toolkit 4.0tools to build the open grid service framework and encapsulats data resources based on Web Services Resource Framework(WSRF).The system uses the middleware technology to provide unified access interface for heterogeneous data interaction,which could optimize interactive process with virtualized service to query and call tumor information resources flexibly.For massive amounts of heterogeneous tumor data,the federated stored and multiple authorized mode is selected as security services mechanism,real-time monitoring and balancing load.The system can cooperatively manage multi-center heterogeneous tumor data to realize the tumor patient data query,sharing and analysis,and compare and match resources in typical clinical database or clinical information database in other service node,thus it can assist doctors in consulting similar case and making up multidisciplinary treatment plan for tumors.Consequently,the system can improve efficiency of diagnosis and treatment for tumor,and promote the development of collaborative tumor diagnosis model.

Hierarchical Context Modeling for Video Event Recognition.

PubMed

Wang, Xiaoyang; Ji, Qiang

2016-10-11

Current video event recognition research remains largely target-centered. For real-world surveillance videos, targetcentered event recognition faces great challenges due to large intra-class target variation, limited image resolution, and poor detection and tracking results. To mitigate these challenges, we introduced a context-augmented video event recognition approach. Specifically, we explicitly capture different types of contexts from three levels including image level, semantic level, and prior level. At the image level, we introduce two types of contextual features including the appearance context features and interaction context features to capture the appearance of context objects and their interactions with the target objects. At the semantic level, we propose a deep model based on deep Boltzmann machine to learn event object representations and their interactions. At the prior level, we utilize two types of prior-level contexts including scene priming and dynamic cueing. Finally, we introduce a hierarchical context model that systematically integrates the contextual information at different levels. Through the hierarchical context model, contexts at different levels jointly contribute to the event recognition. We evaluate the hierarchical context model for event recognition on benchmark surveillance video datasets. Results show that incorporating contexts in each level can improve event recognition performance, and jointly integrating three levels of contexts through our hierarchical model achieves the best performance.

Integrating epigenomic data and 3D genomic structure with a new measure of chromatin assortativity.

PubMed

Pancaldi, Vera; Carrillo-de-Santa-Pau, Enrique; Javierre, Biola Maria; Juan, David; Fraser, Peter; Spivakov, Mikhail; Valencia, Alfonso; Rico, Daniel

2016-07-08

Network analysis is a powerful way of modeling chromatin interactions. Assortativity is a network property used in social sciences to identify factors affecting how people establish social ties. We propose a new approach, using chromatin assortativity, to integrate the epigenomic landscape of a specific cell type with its chromatin interaction network and thus investigate which proteins or chromatin marks mediate genomic contacts. We use high-resolution promoter capture Hi-C and Hi-Cap data as well as ChIA-PET data from mouse embryonic stem cells to investigate promoter-centered chromatin interaction networks and calculate the presence of specific epigenomic features in the chromatin fragments constituting the nodes of the network. We estimate the association of these features with the topology of four chromatin interaction networks and identify features localized in connected areas of the network. Polycomb group proteins and associated histone marks are the features with the highest chromatin assortativity in promoter-centered networks. We then ask which features distinguish contacts amongst promoters from contacts between promoters and other genomic elements. We observe higher chromatin assortativity of the actively elongating form of RNA polymerase 2 (RNAPII) compared with inactive forms only in interactions between promoters and other elements. Contacts among promoters and between promoters and other elements have different characteristic epigenomic features. We identify a possible role for the elongating form of RNAPII in mediating interactions among promoters, enhancers, and transcribed gene bodies. Our approach facilitates the study of multiple genome-wide epigenomic profiles, considering network topology and allowing the comparison of chromatin interaction networks.

Final Technical Report - SciDAC Cooperative Agreement: Center for Wave Interactions with Magnetohydrodynamics

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

Schnack, Dalton D.

Final technical report for research performed by Dr. Thomas G. Jenkins in collaboration with Professor Dalton D. Schnack on SciDAC Cooperative Agreement: Center for Wave Interactions with Magnetohydrodyanics, DE-FC02-06ER54899, for the period of 8/15/06 - 8/14/11. This report centers on the Slow MHD physics campaign work performed by Dr. Jenkins while at UW-Madison and then at Tech-X Corporation. To make progress on the problem of RF induced currents affect magnetic island evolution in toroidal plasmas, a set of research approaches are outlined. Three approaches can be addressed in parallel. These are: (1) Analytically prescribed additional term in Ohm's law tomore » model the effect of localized ECCD current drive; (2) Introduce an additional evolution equation for the Ohm's law source term. Establish a RF source 'box' where information from the RF code couples to the fluid evolution; and (3) Carry out a more rigorous analytic calculation treating the additional RF terms in a closure problem. These approaches rely on the necessity of reinvigorating the computation modeling efforts of resistive and neoclassical tearing modes with present day versions of the numerical tools. For the RF community, the relevant action item is - RF ray tracing codes need to be modified so that general three-dimensional spatial information can be obtained. Further, interface efforts between the two codes require work as well as an assessment as to the numerical stability properties of the procedures to be used.« less

Increased Learning Observed in Redesigned Introductory Biology Course that Employed Web-enhanced, Interactive Pedagogy

PubMed Central

Lister, Bradford C.; Hanna, Michael H.; Roy, Harry

2007-01-01

Our Introduction to Biology course (BIOL 1010) changed in 2004 from a standard instructor-centered, lecture-homework-exam format to a student-centered format that used Web-enhanced, interactive pedagogy. To measure and compare conceptual learning gains in the traditional course in fall 2003 with a section of the interactive course in fall 2004, we created concept inventories for both evolution and ecology. Both classes were taught by the same instructor who had taught BIOL 1010 since 1976, and each had a similar student composition with comparable biological knowledge. A significant increase in learning gain was observed with the Web-enhanced, interactive pedagogy in evolution (traditional, 0.10; interactive, 0.19; p = 0.024) and ecology (traditional, −0.05; interactive, 0.14; p = 0.000009) when assessment was made unannounced and for no credit in the last week of classes. These results strengthen the case for augmenting or replacing instructor-centered teaching with Web-enhanced, interactive, student-centered teaching. When assessment was made using the final exam in the interactive course, for credit and after studying, significantly greater learning gains were made in evolution (95%, 0.37, p = 0.0001) and ecology (143%, 0.34, p = 0.000003) when compared with learning gains measured without credit or study in the last week of classes. PMID:17785407

New techniques for experimental generation of two-dimensional blade-vortex interaction at low Reynolds numbers

NASA Technical Reports Server (NTRS)

Booth, E., Jr.; Yu, J. C.

1986-01-01

An experimental investigation of two dimensional blade vortex interaction was held at NASA Langley Research Center. The first phase was a flow visualization study to document the approach process of a two dimensional vortex as it encountered a loaded blade model. To accomplish the flow visualization study, a method for generating two dimensional vortex filaments was required. The numerical study used to define a new vortex generation process and the use of this process in the flow visualization study were documented. Additionally, photographic techniques and data analysis methods used in the flow visualization study are examined.

Chandra Interactive Analysis of Observations (CIAO)

NASA Technical Reports Server (NTRS)

Dobrzycki, Adam

2000-01-01

The Chandra (formerly AXAF) telescope, launched on July 23, 1999, provides X-rays data with unprecedented spatial and spectral resolution. As part of the Chandra scientific support, the Chandra X-ray Observatory Center provides a new data analysis system, CIAO ("Chandra Interactive Analysis of Observations"). We will present the main components of the system: "First Look" analysis; SHERPA: a multi-dimensional, multi-mission modeling and fitting application; Chandra Imaging and Plotting System; Detect package-source detection algorithms; and DM package generic data manipulation tools, We will set up a demonstration of the portable version of the system and show examples of Chandra Data Analysis.

Studies of Solar Wind Interaction and Ionospheric Processes at Venus and Mars

NASA Technical Reports Server (NTRS)

Bogan, Denis (Technical Monitor); Nagy, Andrew F.

2003-01-01

This is the final report summarizing the work done during the last three years under NASA Grant NAG5-8946. Our efforts centered on a systematic development of a new generation of three dimensional magneto-hydrodynamic (MHD) numerical code, which models the interaction processes of the solar wind or fast flowing magnetospheric plasma with 'non-magnetic' solar system bodies (e.g. Venus, Mars, Europa, Titan). We have also worked on a number of different, more specific and discrete studies, as various opportunities arose. In the next few pages we briefly summarize these efforts.

[Thinking on the Training of Uniportal Video-assisted Thoracic Surgery].

PubMed

Zhu, Yuming; Jiang, Gening

2018-04-20

Recently, uniportal video-assisted thoracic surgery (VATS) has developed rapidly and has become the main theme of global surgical development. The specific, standardized and systematic training of this technology has become an important topic. Specific training in the uniportal VATS approach is crucial to ensure safety and radical treatment. Such training approach, including a direct interaction with experienced surgeons in high-volume centers, is crucial and represents an indispensable step. Another form of training that usually occurs after preceptorship is proctorship: an experienced mentor can be invited to a trainee's own center to provide specific on-site tutelage. Videos published online are commonly used as training material. Technology has allowed the use of different models of simulators for training. The most common model is the use of animal wet laboratory training. Other models, however, have been used mostrecently, such as the use of 3D and VR Technology, virtual reality simulators, and completely artificial models of the human thorax with synthetic lung, vessel, airway, and nodal tissues. A short-duration, high-volume, clinical immersion training, and a long term systematic training in high-volume centers are getting more and more attention. According to the evaluation of students' grading, a diversified training mode is adopted and the targeted training in accordance with different students helps to improve the training effect. We have done some work in systematic and standardized training of uniportal VATS in single center. We believe such training is feasible and absolutely necessary.

Local condensate depletion at trap center under strong interactions

NASA Astrophysics Data System (ADS)

Yukalov, V. I.; Yukalova, E. P.

2018-04-01

Cold trapped Bose-condensed atoms, interacting via hard-sphere repulsive potentials are considered. Simple mean-field approximations show that the condensate distribution inside a harmonic trap always has the shape of a hump with the maximum condensate density occurring at the trap center. However, Monte Carlo simulations at high density and strong interactions display the condensate depletion at the trap center. The explanation of this effect of local condensate depletion at trap center is suggested in the frame of self-consistent theory of Bose-condensed systems. The depletion is shown to be due to the existence of the anomalous average that takes into account pair correlations and appears in systems with broken gauge symmetry.

Educational Applications of Astronomy & Space Flight Operations at the Kennedy Space Center

NASA Astrophysics Data System (ADS)

Erickson, L. K.

1999-09-01

Within two years, the Kennedy Space Center will complete a total redesign of NASA's busiest Visitor's Center. Three million visitors per year will be witness to a new program focused on expanding the interests of the younger public in NASA's major space programs, in space operations, and in astronomy. This project, being developed through the Visitor's Center director, a NASA faculty fellow, and the Visitor's Center contractor, is centered on the interaction between NASA programs, the visiting youth, and their parents. The goal of the Center's program is to provide an appealing learning experience for teens and pre teens using stimulating displays and interactive exhibits that are also educational.

A qualitative analysis of patient-centered dentistry in consultations with dental phobic patients.

PubMed

Kulich, Károly R; Berggren, Ulf; Hallberg, Lillemor R-M

2003-01-01

Dental phobia is regarded as one of the greatest obstructions to adequate dental care. It has long been established that fearful dental patients are particularly sensitive to dentists' behavior and performance of dental care. There is a need for the establishment of a systematic theory of dentist-patient communication and new methods analyzing how dentists interact with their patients. In this qualitative study, thirty semi-structured interviews were conducted in 1998 and 1999 with five dentists (three male and two female). Dentists consulted on two occasions with 15 newly enrolled, consecutive dental phobic patients (2 male and 13 female) in a Swedish clinic specializing in the treatment of odontophobia. The time interval between consultation one and two was approximately 2-3 weeks. Analysis of the transcribed interviews was based by the principles of Grounded Theory. The study identified one core category, "Holistic perception and understanding of the patient", two categories, "The dentist's positive outlook on people" and "The dentist's positive view of patient contact", and six further subcategories. Findings support previous models of patient-centered medicine and contribute to a better understanding of how patient-centered dentists interact with dental phobic patients.

What the Milky Way's dwarfs tell us about the Galactic Center extended gamma-ray excess

NASA Astrophysics Data System (ADS)

Keeley, Ryan E.; Abazajian, Kevork N.; Kwa, Anna; Rodd, Nicholas L.; Safdi, Benjamin R.

2018-05-01

The Milky Way's Galactic Center harbors a gamma-ray excess that is a candidate signal of annihilating dark matter. Dwarf galaxies remain predominantly dark in their expected commensurate emission. In this work we quantify the degree of consistency between these two observations through a joint likelihood analysis. In doing so we incorporate Milky Way dark matter halo profile uncertainties, as well as an accounting of diffuse gamma-ray emission uncertainties in dark matter annihilation models for the Galactic Center extended gamma-ray excess (GCE) detected by the Fermi Gamma-Ray Space Telescope. The preferred range of annihilation rates and masses expands when including these unknowns. Even so, using two recent determinations of the Milky Way halo's local density leaves the GCE preferred region of single-channel dark matter annihilation models to be in strong tension with annihilation searches in combined dwarf galaxy analyses. A third, higher Milky Way density determination, alleviates this tension. Our joint likelihood analysis allows us to quantify this inconsistency. We provide a set of tools for testing dark matter annihilation models' consistency within this combined data set. As an example, we test a representative inverse Compton sourced self-interacting dark matter model, which is consistent with both the GCE and dwarfs.

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

Ehlen, Mark A.; Sun, Amy C.; Pepple, Mark A.

The potential impacts of man-made and natural disasters on chemical plants, complexes, and supply chains are of great importance to homeland security. To be able to estimate these impacts, we developed an agent-based chemical supply chain model that includes: chemical plants with enterprise operations such as purchasing, production scheduling, and inventories; merchant chemical markets, and multi-modal chemical shipments. Large-scale simulations of chemical-plant activities and supply chain interactions, running on desktop computers, are used to estimate the scope and duration of disruptive-event impacts, and overall system resilience, based on the extent to which individual chemical plants can adjust their internal operationsmore » (e.g., production mixes and levels) versus their external interactions (market sales and purchases, and transportation routes and modes). As a result, to illustrate how the model estimates the impacts of a hurricane disruption, a simple example model centered on 1,4-butanediol is presented.« less

A case study: the evolution of a "facilitator model" liaison program in an academic medical library.

PubMed

Crossno, Jon E; DeShay, Claudia H; Huslig, Mary Ann; Mayo, Helen G; Patridge, Emily F

2012-07-01

What type of liaison program would best utilize both librarians and other library staff to effectively promote library services and resources to campus departments? The case is an academic medical center library serving a large, diverse campus. The library implemented a "facilitator model" program to provide personalized service to targeted clients that allowed for maximum staff participation with limited subject familiarity. To determine success, details of liaison-contact interactions and results of liaison and department surveys were reviewed. Liaisons successfully recorded 595 interactions during the program's first 10 months of existence. A significant majority of departmental contact persons (82.5%) indicated they were aware of the liaison program, and 75% indicated they preferred email communication. The "facilitator model" provides a well-defined structure for assigning liaisons to departments or groups; however, training is essential to ensure that liaisons are able to communicate effectively with their clients.

Prospects for detecting a net photon circular polarization produced by decaying dark matter

NASA Astrophysics Data System (ADS)

Elagin, Andrey; Kumar, Jason; Sandick, Pearl; Teng, Fei

2017-11-01

If dark matter interactions with Standard Model particles are C P violating, then dark matter annihilation/decay can produce photons with a net circular polarization. We consider the prospects for experimentally detecting evidence for such a circular polarization. We identify optimal models for dark matter interactions with the Standard Model, from the point of view of detectability of the net polarization, for the case of either symmetric or asymmetric dark matter. We find that, for symmetric dark matter, evidence for net polarization could be found by a search of the Galactic center by an instrument sensitive to circular polarization with an efficiency-weighted exposure of at least 50 ,000 cm2 yr , provided the systematic detector uncertainties are constrained at the 1% level. Better sensitivity can be obtained in the case of asymmetric dark matter. We discuss the prospects for achieving the needed level of performance using possible detector technologies.

Do Community and Caregiver Factors Influence Hospice Use at the End of Life Among Older Adults With Alzheimer Disease?

PubMed

Karikari-Martin, Pauline; McCann, Judith J; Hebert, Liesi E; Haffer, Samuel C; Phillips, Marcia

2012-05-01

Hospice is an underused service among people with Alzheimer disease. This study used the Hospice Use Model to examine community, care recipient, and caregiver characteristics associated with hospice use before death among 145 community-dwelling care recipients with Alzheimer disease and their caregivers. Secondary analysis using logistic regression modeling indicated that older age, male gender, black race, and better functional health of care recipients with Alzheimer disease were associated with a decreased likelihood of using hospice (model χ 2 5 = 23.5, P = .0003). Moreover, care recipients recruited from an Alzheimer clinic were more likely to use hospice than those recruited from adult day-care centers. Caregiver factors were not independent predictors of hospice use. However, there was a significant interaction between hours of care provided each week and recruitment site. Among care recipients from the Alzheimer clinic, the probability of hospice use increased as caregiving intensity increased. This relationship was reversed in care recipients from day-care centers. Results suggest that adult day-care centers need to partner with hospice programs in the community. In conclusion, care recipient and community service factors influence hospice use in individuals with Alzheimer disease.

Solution structure of Apaf-1 CARD and its interaction with caspase-9 CARD: a structural basis for specific adaptor/caspase interaction.

PubMed

Zhou, P; Chou, J; Olea, R S; Yuan, J; Wagner, G

1999-09-28

Direct recruitment and activation of caspase-9 by Apaf-1 through the homophilic CARD/CARD (Caspase Recruitment Domain) interaction is critical for the activation of caspases downstream of mitochondrial damage in apoptosis. Here we report the solution structure of the Apaf-1 CARD domain and its surface of interaction with caspase-9 CARD. Apaf-1 CARD consists of six tightly packed amphipathic alpha-helices and is topologically similar to the RAIDD CARD, with the exception of a kink observed in the middle of the N-terminal helix. By using chemical shift perturbation data, the homophilic interaction was mapped to the acidic surface of Apaf-1 CARD centered around helices 2 and 3. Interestingly, a significant portion of the chemically perturbed residues are hydrophobic, indicating that in addition to the electrostatic interactions predicted previously, hydrophobic interaction is also an important driving force underlying the CARD/CARD interaction. On the basis of the identified functional residues of Apaf-1 CARD and the surface charge complementarity, we propose a model of CARD/CARD interaction between Apaf-1 and caspase-9.

Contribution to the Study of Nuclear Interactions at Several Tens of Bev by Means of Cosmic Radiations (thesis); CONTRIBUTION A L'ETUDE DES INTERACTIONS NUCLEAIRES DE PLUSIEURS DIZAINES DE Gev., AU MOYEN DES RAYONS COSMIQUES (THESES)

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

Pelletier, C.

1960-01-01

The secondaries produced by the interaction of highenergy cosmic radiation with aluminum were studied with Wilson chambers placed in a magnetic field. From 9600 photographs made, 117 interactions of charged particles with energy higher than 10 Bev in aluminum were selected. These photographs were obtained with the apparatus installed at the Observatory of the Pic du Midi de Bigorre. This apparatus is described. The quantities of motion and the emission direction of charged secondaries of each interaction were determined. The measurements and the methods of calculation are described. The results obtained on charged secondaries and unstable particles are reported. Themore » selection of the interactions which occurred with only one nucleon of the aluminum nucleus is discussed. These interactions were studied in the center-of-mass system of the interacting particles. The results obtained are compared with the predictions of the principal theoreticat models of nucleon-nucleon interactions. (trauth)« less

On the Relationality of Centers, Peripheries and Interactional Regimes: Translanguaging in a Community Interpreting Event

ERIC Educational Resources Information Center

Baynham, Mike; Hanušová, Jolana

2017-01-01

In this paper we discuss a multilingual interactional event that involves both interpreting and literacy work, part of a large scale study on translanguaging in superdiverse urban settings. In the first part of the interaction, the center/periphery dynamic is played out in what might be called "contested translanguaging" between Standard…

Internet of People: Opportunities and challenges for engaging stakeholders in watershed planning via the Web

NASA Astrophysics Data System (ADS)

Babbar-Sebens, M.

2016-12-01

Social computing technologies are transforming the way our society interacts and generates content on the Web via collective intelligence. Previously unimagined possibilities have arisen for using these technologies to engage stakeholders and involve them in policy making and planning efforts. While the Internet has been used in the past to support education and communication endeavors, we have developed a novel, web-based, interactive planning tool that engages the community in using science-based methods for the design of potential conservation practices on their landscape, and thereby, reducing undesirable impacts of extreme hydroclimatic events. The tool, Watershed REstoration using Spatio-Temporal Optimization of Resources (WRESTORE), uses a democratic voting process coupled with visualization interfaces, computational simulation and optimization models, and user modeling techniques to support a human-centered design approach. This human-centered design approach, which is reinforced by use of Web 2.0 technologies, has the potential to enable policy makers to connect to a larger community of stakeholders and directly engage them in environmental stewardship efforts. Additionally, the design framework can be used by watershed groups to plug-in their own hydrologic models, climate observations and forecasts, and various other simulation models unique to their watersheds. In this presentation, we will demonstrate the effectiveness of WRESTORE for designing alternatives of conservation practices in a HUC-11 Midwestern watershed, results of various experiments with a diverse set of test users and stakeholders, and discuss potential for future developments.

Microscopic theory of Dzyaloshinsky-Moriya interaction in pyrochlore oxides with spin-orbit coupling

NASA Astrophysics Data System (ADS)

Arakawa, Naoya

2016-10-01

Pyrochlore oxides show several fascinating phenomena, such as the formation of heavy fermions and the thermal Hall effect. Although a key to understanding some phenomena may be the Dzyaloshinsky-Moriya (DM) interaction, its microscopic origin is unclear. To clarify the microscopic origin, we constructed a t2 g-orbital model with the kinetic energy, the trigonal-distortion potential, the multiorbital Hubbard interactions, and the L S coupling, and derived the low-energy effective Hamiltonian for a d1 Mott insulator with the weak L S coupling. We first show that lack of the inversion center of each nearest-neighbor V-V bond causes the odd-mirror interorbital hopping integrals. Those are qualitatively different from the even-mirror hopping integrals, existing even with the inversion center. We next show that the second-order perturbation using the kinetic terms leads to the ferromagnetic and the antiferromagnetic superexchange interactions, whose competition is controllable by tuning the Hubbard interactions. Then, we show the most important result: the third-order perturbation terms using the combination of the even-mirror hopping integral, the odd-mirror hopping integral, and the L S coupling causes the DM interaction due to the mirror-mixing effect, where those hopping integrals are necessary to obtain the antisymmetric kinetic exchange and the L S coupling is necessary to excite the orbital angular momentum at one of two sites. We also show that the magnitude and sign of the DM interaction can be controlled by changing the positions of the O ions and the strength of the Hubbard interactions. We discuss the advantages in comparison with the phenomenological theory and Moriya's microscopic theory, applicability of our mechanism, and the similarities and differences between our case and the strong-L S -coupling case.

Boosted dark matter signals uplifted with self-interaction

DOE PAGES

Kong, Kyoungchul; Mohlabeng, Gopolang; Park, Jong -Chul

2015-04-01

We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in themore » assisted freeze-out mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier) dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.« less

Boosted dark matter signals uplifted with self-interaction

NASA Astrophysics Data System (ADS)

Kong, Kyoungchul; Mohlabeng, Gopolang; Park, Jong-Chul

2015-04-01

We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in the assisted freeze-out mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier) dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.

Buzzwords and newspeak

NASA Astrophysics Data System (ADS)

Swartz, Clifford E.

2000-03-01

You have to read beneath the lines in this business. Every week I get manuscripts filled with words and phrases fraught with cabalistic meaning. Would you believe, for instance, that in using the modeling method of teaching that the carefully structured development and concept flow would lead through Socratic dialogue to a rich classroom discourse? Perhaps it would help if I reminded you that a model is a primary unit of coherently structured knowledge. Of course, I am speaking only of the essence of models that are at the heart of modeling theory. These depend on student-centered teaching that is research-informed, leading to interactive engagement methods and cooperative learning.

Polaron Thermodynamics of Spin-Imbalanced Quasi-Two-Dimensional Fermi Gases

NASA Astrophysics Data System (ADS)

Ong, Willie; Cheng, Chingyun; Arakelyan, Ilya; Thomas, John

2015-05-01

We present the first spatial profile measurements for spin-imbalanced mixtures of atomic 6Li fermions in a quasi-2D geometry with tunable strong interactions. The observed minority and majority profiles are not correctly predicted by BCS theory for a true 2D system, but are reasonably well fit by a 2D-polaron model of the free energy. Density difference profiles reveal a flat center with two peaks at the edges, consistent with a fully paired core of the corresponding 2D density profiles. These features are more prominent for higher interaction strengths. Not predicted by the polaron model is an observed transition from a spin-imbalanced normal fluid phase to a spin-balanced central core above a critical imbalance. Supported by ARO, DOE, AFOSR, NSF.

Results of test 0A82 in the NASA/LRC 31 inch CFHT on an 0.010-scale model (32-0) of the space shuttle configuration 3 to determine RCS jet flow field interaction and to investigate RT real gas effects

NASA Technical Reports Server (NTRS)

Thornton, D. E.

1975-01-01

Tests were conducted in the NASA Langley Research Center 31-inch Continuous Flow Hypersonic Wind Tunnel to determine RCS jet interaction effects on hypersonic aerodynamic characteristics and to investigate RT (gas constant times temperature) scaling effects on the RCS similitude. The model was an 0.010-scale replica of the Space Shuttle Orbiter Configuration 3. Hypersonic aerodynamic data were obtained from tests at Mach 10.3 and dynamic pressures of 200, 150, 125, and 100 psf. The RCS modes of pitch, yaw, and roll at free flight dynamic pressure simulation of 20 psf were investigated.

NPLOT: an Interactive Plotting Program for NASTRAN Finite Element Models

NASA Technical Reports Server (NTRS)

Jones, G. K.; Mcentire, K. J.

1985-01-01

The NPLOT (NASTRAN Plot) is an interactive computer graphics program for plotting undeformed and deformed NASTRAN finite element models. Developed at NASA's Goddard Space Flight Center, the program provides flexible element selection and grid point, ASET and SPC degree of freedom labelling. It is easy to use and provides a combination menu and command driven user interface. NPLOT also provides very fast hidden line and haloed line algorithms. The hidden line algorithm in NPLOT proved to be both very accurate and several times faster than other existing hidden line algorithms. A fast spatial bucket sort and horizon edge computation are used to achieve this high level of performance. The hidden line and the haloed line algorithms are the primary features that make NPLOT different from other plotting programs.

Effects of reaction control system jet flow field interactions on the aerodynamic characteristics of a 0.010-scale space shuttle orbiter model in the Langley Research Center 31 inch CFHT (OA85)

NASA Technical Reports Server (NTRS)

Daileda, J. J.; Marroquin, J.

1974-01-01

An experimental investigation was conducted to obtain detailed effects on supersonic vehicle hypersonic aerodynamic and stability and control characteristics of reaction control system jet flow field interactions with the local vehicle flow field. A 0.010-scale model was used. Six-component force data and wing, elevon, and body flap surface pressure data were obtained through an angle-of-attack range of -10 to +35 degrees with 0 deg angle of sideslip. The test was conducted with yaw, pitch and roll jet simulation at a free-stream Mach number of 10.3 and reaction control system plume simulation of flight dynamic pressures of 5, 10 and 20 PSF.

Analytical and experimental study of the effects of wing-body aerodynamic interaction on space shuttle subsonic flutter

NASA Technical Reports Server (NTRS)

Chipman, R. R.; Rauch, F. J.

1975-01-01

The effects on flutter of the aerodynamic interaction between the space shuttle bodies and wing, 1/80th-scale semispan models of the orbiter wing, the complete shuttle and intermediate component combinations were tested in the NASA Langley Research Center 26-inch Transonic Blowdown Wind Tunnel. Using the double lattice method combined with slender body theory to calculate unsteady aerodynamic forces, subsonic flutter speeds were computed for comparison. Using calculated complete vehicle modes, flutter speed trends were computed for the full scale vehicle at an altitude of 15,200 meters and a Mach number of 0.6. Consistent with findings of the model studies, analysis shows the shuttle to have the same flutter speed as an isolated cantilevered wing.

Cultural health capital and the interactional dynamics of patient-centered care

PubMed Central

Dubbin, Leslie A.; Chang, Jamie Suki; Shim, Janet K.

2014-01-01

As intuitive and inviting as it may appear, the concept of patient-centered care has been difficult to conceptualize, institutionalize and operationalize. Informed by Bourdieu's concepts of cultural capital and habitus, we employ the framework of cultural health capital to uncover the ways in which both patients' and providers' cultural resources, assets, and interactional styles influence their abilities to mutually achieve patient-centered care. Cultural health capital is defined as a specialized collection of cultural skills, attitudes, behaviors and interactional styles that are valued, leveraged, and exchanged by both patients and providers during clinical interactions. In this paper, we report the findings of a qualitative study conducted from 2010 to 2011 in the Western United States. We investigated the various elements of cultural health capital, how patients and providers used cultural health capital to engage with each other, and how this process shaped the patient-centeredness of interactions. We find that the accomplishment of patient-centered care is highly dependent upon habitus and the cultural health capital that both patients and providers bring to health care interactions. Not only are some cultural resources more highly valued than others, their differential mobilization can facilitate or impede engagement and communication between patients and their providers. The focus of cultural health capital on the ways fundamental social inequalities are manifest in clinical interactions enables providers, patients, and health care organizations to consider how such inequalities can confound patient-centered care. PMID:23906128

Computational and Experimental Study of Supersonic Nozzle Flow and Aft-Deck Interactions

NASA Technical Reports Server (NTRS)

Bruce, Walter E., IV; Carter, Melissa B.; Elmiligui, Alaa A.; Winski, Courtney S.; Nayani, Sudheer N.; Castner, Raymond S.

2016-01-01

NASA has been conducting research into reducing sonic boom and changing FAA regulations to allow for supersonic commercial transport over land in the United States. This particular study looks at a plume passing through a shock generated from an aft deck on a nacelle; the aft deck is meant to represent the trailing edge of a wing. NASA Langley Research Center USM3D CFD code results are compared to the experimental data taken at the NASA Glenn Research Center 1-foot by 1-foot Supersonic Wind Tunnel. This study included examining two turbulence models along with different volume sourcing methods for grid generation. The results show that using the k-epsilon turbulence model within USM3D produced shock signatures that closely follow the experimental data at a variety of nozzle pressure ratio settings.

Patient perspectives on tobacco use treatment in primary care.

PubMed

Halladay, Jacqueline R; Vu, Maihan; Ripley-Moffitt, Carol; Gupta, Sachin K; O'Meara, Christine; Goldstein, Adam O

2015-02-05

Evidence-based tobacco cessation interventions increase quit rates, yet most smokers do not use them. Every primary care visit offers the potential to discuss such options, but communication can be tricky for patients and provider alike. We explored smokers' personal interactions with health care providers to better understand what it is like to be a smoker in an increasingly smoke-free era and the resources needed to support quit attempts and to better define important patient-centered outcomes. Three 90-minute focus groups, involving 33 patients from 3 primary care clinics, were conducted. Participants were current or recent (having quit within 6 months) smokers. Topics included tobacco use, quit attempts, and interactions with providers, followed by more pointed questions exploring actions patients want from providers and outcome measures that would be meaningful to patients. Four themes were identified through inductive coding techniques: 1) the experience of being a tobacco user (inconvenience, shame, isolation, risks, and benefits), 2) the medical encounter (expectations of providers, trust and respect, and positive, targeted messaging), 3) high-value actions (consistent dialogue, the addiction model, point-of-care nicotine patches, educational materials, carbon monoxide monitoring, and infrastructure), and 4) patient-centered outcomes. Engaged patient-centered smoking cessation counseling requires seeking the patient voice early in the process. Participants desired honest, consistent, and pro-active discussions and actions. Participants also suggested creative patient-centered outcome measures to consider in future research.

The NASA-Goddard Multi-Scale Modeling Framework - Land Information System: Global Land/atmosphere Interaction with Resolved Convection

NASA Technical Reports Server (NTRS)

Mohr, Karen Irene; Tao, Wei-Kuo; Chern, Jiun-Dar; Kumar, Sujay V.; Peters-Lidard, Christa D.

2013-01-01

The present generation of general circulation models (GCM) use parameterized cumulus schemes and run at hydrostatic grid resolutions. To improve the representation of cloud-scale moist processes and landeatmosphere interactions, a global, Multi-scale Modeling Framework (MMF) coupled to the Land Information System (LIS) has been developed at NASA-Goddard Space Flight Center. The MMFeLIS has three components, a finite-volume (fv) GCM (Goddard Earth Observing System Ver. 4, GEOS-4), a 2D cloud-resolving model (Goddard Cumulus Ensemble, GCE), and the LIS, representing the large-scale atmospheric circulation, cloud processes, and land surface processes, respectively. The non-hydrostatic GCE model replaces the single-column cumulus parameterization of fvGCM. The model grid is composed of an array of fvGCM gridcells each with a series of embedded GCE models. A horizontal coupling strategy, GCE4fvGCM4Coupler4LIS, offered significant computational efficiency, with the scalability and I/O capabilities of LIS permitting landeatmosphere interactions at cloud-scale. Global simulations of 2007e2008 and comparisons to observations and reanalysis products were conducted. Using two different versions of the same land surface model but the same initial conditions, divergence in regional, synoptic-scale surface pressure patterns emerged within two weeks. The sensitivity of largescale circulations to land surface model physics revealed significant functional value to using a scalable, multi-model land surface modeling system in global weather and climate prediction.

[Evaluating the accuracy of three-dimensional reconstruction of the intercuspal position for dentition casts aided by a mechanical appliance].

PubMed

Hu, Z W; Li, W W; Zhang, X Y; Fan, B L; Wang, Y; Sun, Y C

2016-08-01

To develop a aided mechanical appliance for rapid reconstruction of three-dimensional(3D)relationship of dentition model after scanning and evaluation of its accuracy. The appliance was designed by forward engineering software and fabricated by a high precision computer numerical control(CNC)system. It contained upper and lower body, magnetic pedestal and three pillars. Nine 3 mm diameter hemispheres were distributed equally on the axial surface of each pedestal. Faro Edge 1.8m was used to directly obtain center of each hemisphere(contact method), defined as known center. A pair of die-stone standard dentition model were fixed in intercuspal position and then fixed on the magnetic pedestals with low expansion ratio plaster. Activity 880 dental scanner was used to scan casts after the plaster was completely set. In Geomagic 2012, the centers of each hemisphere were fitted and defined as scanning centers. Scanning centers were aligned to known centers by reference point system to finish the 3D reconstruction of the intercuspal occlusion for the dentition casts. An observation coordinate system was interactively established. The straight-line distances in the X(coronal), Y(saggital), and Z(vertical)between the remaining 6 pairs of center points derived from contact method and fitting method were measured respectively and analyzed using a paired t-test. The differences of the straight-line distances of the remaining 6 pairs of center points between the two methods were X:(-0.05±0.10)mm, Y:(0.02±0.06)mm, and Z:(0.01 ± 0.05)mm. The results of paired t-test showed no significant differences(P>0.05). The mechanical appliance can help to reconstruct 3D jaw relation by scanning single upper and lower dentition model with usual commercial available dental cast scanning system.

Assessing the extent of utilization of biopsychosocial model in doctor–patient interaction in public sector hospitals of a developing country

PubMed Central

Nadir, Maha; Hamza, Muhammad; Mehmood, Nadir

2018-01-01

Background: Biopsychosocial (BPS) model has been a mainstay in the ideal practice of modern medicine. It is attributed to improve patient care, compliance, and satisfaction and to reduce doctor–patient conflict. The study aimed to understand the importance given to BPS model while conducting routine doctor–patient interactions in public sector hospitals of a developing country where health resources are limited. The study was conducted in Rawalpindi, Pakistan. Materials and Methods: The study design is qualitative. Structured interviews were conducted from 44 patients from surgical and medical units of Benazir Bhutto Hospital and Holy Family Hospital. The questions were formulated based on patient-centered interviewing methods by reviewing the literature on BPS model. The analysis was done thematically using the software NVivo 11 for qualitative data. Results: The study revealed four emerging themes: (1) Lack of doctor–patient rapport. (2) Utilization of a paternalistic approach during treatment. (3) Utilization of a reductionist biomedical approach during treatment. (4) Patients’ concern with their improvement in health and doctor's demeanor. Conclusion: The study highlights the fact that BPS is not given considerable importance while taking routine medical history. This process remains doctor centered and paternalistic. However, patients are more concerned with their improvement in health rather than whether or not they are being provided informational care. Sequential studies will have to be conducted to determine whether this significantly affects patient care and compliance and whether BPS is a workable model in the healthcare system in the third world. PMID:29736071

Setting realistic recovery targets for two interacting endangered species, sea otter and northern abalone.

PubMed

Chadès, Iadine; Curtis, Janelle M R; Martin, Tara G

2012-12-01

Failure to account for interactions between endangered species may lead to unexpected population dynamics, inefficient management strategies, waste of scarce resources, and, at worst, increased extinction risk. The importance of species interactions is undisputed, yet recovery targets generally do not account for such interactions. This shortcoming is a consequence of species-centered legislation, but also of uncertainty surrounding the dynamics of species interactions and the complexity of modeling such interactions. The northern sea otter (Enhydra lutris kenyoni) and one of its preferred prey, northern abalone (Haliotis kamtschatkana), are endangered species for which recovery strategies have been developed without consideration of their strong predator-prey interactions. Using simulation-based optimization procedures from artificial intelligence, namely reinforcement learning and stochastic dynamic programming, we combined sea otter and northern abalone population models with functional-response models and examined how different management actions affect population dynamics and the likelihood of achieving recovery targets for each species through time. Recovery targets for these interacting species were difficult to achieve simultaneously in the absence of management. Although sea otters were predicted to recover, achieving abalone recovery targets failed even when threats to abalone such as predation and poaching were reduced. A management strategy entailing a 50% reduction in the poaching of northern abalone was a minimum requirement to reach short-term recovery goals for northern abalone when sea otters were present. Removing sea otters had a marginally positive effect on the abalone population but only when we assumed a functional response with strong predation pressure. Our optimization method could be applied more generally to any interacting threatened or invasive species for which there are multiple conservation objectives. © 2012 Society for Conservation Biology.

Hydrogen bonding and spin density distribution in the QB semiquinone of bacterial reaction centers and comparison with the QA site

PubMed Central

Martin, Erik; Samoilova, Rimma I.; Narasimhulu, Kupala V.; Lin, Tzu-Jen; O’Malley, Patrick J.; Wraight, Colin A.; Dikanov, Sergei A.

2011-01-01

In the photosynthetic reaction center from Rhodobacter sphaeroides, the primary (QA) and secondary (QB) electron acceptors are both ubiquinone-10, but with very different properties and functions. To investigate the protein environment that imparts these functional differences, we have applied X-band HYSCORE, a 2D pulsed EPR technique, to characterize the exchangeable protons around the semiquinone (SQ) in the QA and QB sites, using samples of 15N-labeled reaction centers, with the native high spin Fe2+ exchanged for diamagnetic Zn2+, prepared in 1H2O and 2H2O solvent. The powder HYSCORE method is first validated against the orientation-selected Q-band ENDOR study of the QA SQ by Flores et al. (Biophys. J. 2007, 92, 671–682), with good agreement for two exchangeable protons with anisotropic hyperfine tensor components, T, both in the range 4.6–5.4 MHz. HYSCORE was then applied to the QB SQ where we found proton lines corresponding to T~5.2, 3.7 MHz and T~1.9 MHz. Density functional-based quantum mechanics/molecular mechanics (QM/MM) calculations, employing a model of the QB site, were used to assign the observed couplings to specific hydrogen bonding interactions with the QB SQ. These calculations allow us to assign the T=5.2 MHz proton to the His-L190 NδH…O4 (carbonyl) hydrogen bonding interaction. The T =3.7 MHz spectral feature most likely results from hydrogen bonding interactions of O1 (carbonyl) with both Gly-L225 peptide NH and Ser-L223 hydroxyl OH, which possess calculated couplings very close to this value. The smaller 1.9 MHz coupling is assigned to a weakly bound peptide NH proton of Ile-L224. The calculations performed with this structural model of the QB site show less asymmetric distribution of unpaired spin density over the SQ than seen for the QA site, consistent with available experimental data for 13C and 17O carbonyl hyperfine couplings. The implications of these interactions for QB function and comparisons with the QA site are discussed. PMID:21417328

Mantle Flow and Dehydration Beneath the Juan de Fuca Plate Revealed by Shear Velocity and Attenuation

NASA Astrophysics Data System (ADS)

Ruan, Y.; Forsyth, D. W.; Bell, S. W.

2017-12-01

At mid-ocean-ridge spreading centers, it is still unclear to what extent the upwelling is purely passive, driven by viscous drag of the separating plates, or dynamically driven by the buoyancy induced by melt retention and depletion of the mantle matrix. The distinct sensitivities of seismic wavespeed and attenuation to temperature, melt porosity, water content and major element composition yield some of the primary constraints on mid-ocean ridge processes and the associated flow pattern, melt distribution, and the interaction of spreading centers with hotspots. Extensive arrays of ocean-bottom seismometers (OBS) with better quality, longer deployment periods, and the application of noise-removal techniques together provided higher quality data in this study than in any previous regional study of velocity and attenuation of the upper mantle beneath a spreading center. Based on the fundamental-mode Rayleigh waves, we imaged shear wave attenuation and velocity models in the vicinity of the Juan de Fuca plate with the best resolution to date of any spreading center. There is strong attenuation centered at depths of 70-80 km, just below the expected dry solidus and somewhat deeper than predicted for a model of passive mantle upwelling beneath the spreading center. The shear velocity structure shows lowest velocities west of the spreading center, particularly near Axial Seamount and high velocities east of the axis extending to a greater depth than predicted by the passive flow model. Together, these observations support a model in which buoyant upwelling west of the spreading center first depletes and dehydrates the mantle above the dry solidus by melt removal and then the associated downwelling carries depleted, melt-free, residual mantle downward beneath the Juan de Fuca plate. This depleted, dehydrated, melt-free layer can explain why the average attenuation is lower than expected and the velocity is higher than expected in the 30 to 70 km depth range. The compositional buoyancy of the depleted mantle may in most places limit downwelling to the vicinity of the spinel peridotite to garnet peridotite transition at a depth of 80 km.

Stromal loss of TGFβ drives cancer growth in the epithelium via inflammation | Center for Cancer Research

Cancer.gov

Interactions between epithelial and stromal cells play an important role in cancer development and progression. Epithelial cancers develop when changes occur to tumor suppressor genes in stromal fibroblast cells. For example, loss of tumor suppressor, p53, in stromal fibroblasts leads to p53 inactivation in the epithelium in a prostate cancer model, and disruption of the

Center for Opto-Electronic Systems Research.

DTIC Science & Technology

1988-02-01

Stroud, Jr. The Institute of Optics, University of Rochester Rochester, New York 14627 USA Abstract The Jaynes - Cummings model of a single two-level...surfaces, possibly to include certain classes of surfaces without rotational symmetry. An initial investigation was made of the surface roughness...number density of approximately 1018 - and the forward-going pump wave both enter the nonlinear -.molecules/cm3 . The intensities of the interacting

Northeast Parallel Architectures Center (NPAC)

DTIC Science & Technology

1992-07-01

Computational Techniques: Mapping receptor units to processors , using NEWS communication to model interaction in the inhibitory field Goal of the Research...algorithms for classical problems to take advantage of multiple processors . Experiments in probability that have been too time consuming on serial...machine and achieved speedups of 4 to 5 times with 11 processors . It is believed that a slightly better speedup is achievable. In the case of stuck

The Diverse Data, User Driven Services and the Power of Giovanni at NASA GES DISC

NASA Technical Reports Server (NTRS)

Shen, Suhung

2017-01-01

This presentation provides an overview of remote sensing and model data at GES (Goddard Earth Sciences) DISC (Data and Information Services Center); Overview of data services at GES DISC (Registration with NASA data system; Searching and downloading data); Giovanni (Geospatial Interactive Online VisualizationANd aNalysis Infrastructure): online data exploration tool; and NASA Earth Data and Information System.

A Theorectical Frame of Reference for Rational-Emotive Psychotherapy and Its Application to the Problems of the Under-Achiever.

ERIC Educational Resources Information Center

Konietzko, Kurt

The Rational Emotive Approach centers upon a model in which the human being is seen as a series of systems constantly interacting with others to keep itself functioning. Underlying this approach is the view that it is never the event, but our view of it, which creates the emotional response. Many irrational, culturally structured beliefs cause…

Using Parent and Teacher Voices in the Creation of a Western-Based Early Childhood English-Language Program in China

ERIC Educational Resources Information Center

Shimpi, Priya M.; Paik, Jae H.; Wanerman, Todd; Johnson, Rebecca; Li, Hui; Duh, Shinchieh

2015-01-01

The current English-language research and educational program was driven by an initiative to create a more interactive, theme-based bilingual language education model for preschools in Chengdu, China. During a 2-week teacher education program centered at the Experimental Kindergarten of the Chinese Academy of Sciences in Chengdu, China, a team of…

Decision-support systems for natural-hazards and land-management issues

USGS Publications Warehouse

Dinitz, Laura; Forney, William; Byrd, Kristin

2012-01-01

Scientists at the USGS Western Geographic Science Center are developing decision-support systems (DSSs) for natural-hazards and land-management issues. DSSs are interactive computer-based tools that use data and models to help identify and solve problems. These systems can provide crucial support to policymakers, planners, and communities for making better decisions about long-term natural hazards mitigation and land-use planning.

Computational Study of Thrombus Formation and Clotting Factor Effects under Venous Flow Conditions

DTIC Science & Technology

2016-04-26

Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MarylandABSTRACT A comprehensive... experimental study. The model allowed us to identify the distinct patterns character- izing the spatial distributions of thrombin, platelets, and fibrin...time, elevated fibrinogen levels may contribute to the development of thrombosis (4,6,12). Quantitative knowledge about the interactions between fibrin

Interaction with an Infant by Preschoolers: An Attempt to Modify the Sex Difference.

ERIC Educational Resources Information Center

Blakemore, Judith E. O.

To determine whether modeling of infant care by males would increase young boys' interest in babies, a study was conducted with up to 34 white, middle-class children who attended a university day care center and who ranged in age from 2 to 6 years. Procedures involved 3 days of pretest data collection, 4 weeks of treatment presentation, and 3…

A physical model of sensorimotor interactions during locomotion

NASA Astrophysics Data System (ADS)

Klein, Theresa J.; Lewis, M. Anthony

2012-08-01

In this paper, we describe the development of a bipedal robot that models the neuromuscular architecture of human walking. The body is based on principles derived from human muscular architecture, using muscles on straps to mimic agonist/antagonist muscle action as well as bifunctional muscles. Load sensors in the straps model Golgi tendon organs. The neural architecture is a central pattern generator (CPG) composed of a half-center oscillator combined with phase-modulated reflexes that is simulated using a spiking neural network. We show that the interaction between the reflex system, body dynamics and CPG results in a walking cycle that is entrained to the dynamics of the system. We also show that the CPG helped stabilize the gait against perturbations relative to a purely reflexive system, and compared the joint trajectories to human walking data. This robot represents a complete physical, or ‘neurorobotic’, model of the system, demonstrating the usefulness of this type of robotics research for investigating the neurophysiological processes underlying walking in humans and animals.

The influence of adsorbent microstructure upon adsorption equilibria: Investigations of a model system

NASA Astrophysics Data System (ADS)

Kaminsky, R. D.; Monson, P. A.

1991-08-01

We present a theoretical study of the influence of the microstructure of a porous adsorbent upon associated adsorption behavior. A model is developed which describes the interactions of adsorbed molecules with an adsorbent treated as a matrix of particles each of which is a continuum of interaction centers. The model leads to an analytic expression for the adsorbate-adsorbent particle potential which is an analog of the 9-3 potential model for adsorption on planar solid surfaces. To illustrate the utility of the approach, an application to methane adsorbed in a microporous silica gel is presented. Several adsorbent microstructures are investigated, including a variety of crystal lattices as well as structures derived from equilibrium configurations of hard spheres. Adsorption in these structures is studied through calculation of Henry's law constants and by using grand canonical Monte Carlo simulation to determine adsorption isotherms and the structure of adsorbed fluids. The results obtained are related to details of the adsorbent microstructure.

Searching for an exotic spin-dependent interaction with a single electron-spin quantum sensor.

PubMed

Rong, Xing; Wang, Mengqi; Geng, Jianpei; Qin, Xi; Guo, Maosen; Jiao, Man; Xie, Yijin; Wang, Pengfei; Huang, Pu; Shi, Fazhan; Cai, Yi-Fu; Zou, Chongwen; Du, Jiangfeng

2018-02-21

Searching for new particles beyond the standard model is crucial for understanding several fundamental conundrums in physics and astrophysics. Several hypothetical particles can mediate exotic spin-dependent interactions between ordinary fermions, which enable laboratory searches via the detection of the interactions. Most laboratory searches utilize a macroscopic source and detector, thus allowing the detection of interactions with submillimeter force range and above. It remains a challenge to detect the interactions at shorter force ranges. Here we propose and demonstrate that a near-surface nitrogen-vacancy center in diamond can be utilized as a quantum sensor to detect the monopole-dipole interaction between an electron spin and nucleons. Our result sets a constraint for the electron-nucleon coupling, [Formula: see text], with the force range 0.1-23 μm. The obtained upper bound of the coupling at 20 μm is [Formula: see text] < 6.24 × 10 -15 .

Procedural Modeling for Rapid-Prototyping of Multiple Building Phases

NASA Astrophysics Data System (ADS)

Saldana, M.; Johanson, C.

2013-02-01

RomeLab is a multidisciplinary working group at UCLA that uses the city of Rome as a laboratory for the exploration of research approaches and dissemination practices centered on the intersection of space and time in antiquity. In this paper we present a multiplatform workflow for the rapid-prototyping of historical cityscapes through the use of geographic information systems, procedural modeling, and interactive game development. Our workflow begins by aggregating archaeological data in a GIS database. Next, 3D building models are generated from the ArcMap shapefiles in Esri CityEngine using procedural modeling techniques. A GIS-based terrain model is also adjusted in CityEngine to fit the building elevations. Finally, the terrain and city models are combined in Unity, a game engine which we used to produce web-based interactive environments which are linked to the GIS data using keyhole markup language (KML). The goal of our workflow is to demonstrate that knowledge generated within a first-person virtual world experience can inform the evaluation of data derived from textual and archaeological sources, and vice versa.

Traveling Exhibitions: translating current science into effective science exhibitions

NASA Astrophysics Data System (ADS)

Dusenbery, P.; Morrow, C.; Harold, J.

The Space Science Institute (SSI) of Boulder, Colorado has recently developed two museum exhibits called the Space Weather Center and MarsQuest. It is currently planning to develop two other exhibitions called Cosmic Origins and InterActive Earth. Museum exhibitions provide research scientists the opportunity to engage in a number of activities that are vital to the success of earth and space outreach programs. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. The focus of the presentation will be on the Institute's MarsQuest exhibition. This project is a 5000 square-foot, 2.5M, traveling exhibition that is now touring the country. The exhibit's 3-year tour is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and learn more about their own planet in the process. The associated planetarium show and education program will also be described, with particular emphasis on workshops to orient host museum staff (e.g. museum educators and docents). The workshops make innovative connections between the exhibitions interactive experiences and lesson plans aligned with the National Science Education Standards. SSI is also developing an interactive web site called MarsQuest On-line. The linkage between the web site, education program and exhibit will be discussed. MarsQuest and SSI's other exhibitions are good models for actively involving scientists and their discoveries to help improve informal science education in the museum community and for forging a stronger connection between formal and informal education.

Separating monocular and binocular neural mechanisms mediating chromatic contextual interactions.

PubMed

D'Antona, Anthony D; Christiansen, Jens H; Shevell, Steven K

2014-04-17

When seen in isolation, a light that varies in chromaticity over time is perceived to oscillate in color. Perception of that same time-varying light may be altered by a surrounding light that is also temporally varying in chromaticity. The neural mechanisms that mediate these contextual interactions are the focus of this article. Observers viewed a central test stimulus that varied in chromaticity over time within a larger surround that also varied in chromaticity at the same temporal frequency. Center and surround were presented either to the same eye (monocular condition) or to opposite eyes (dichoptic condition) at the same frequency (3.125, 6.25, or 9.375 Hz). Relative phase between center and surround modulation was varied. In both the monocular and dichoptic conditions, the perceived modulation depth of the central light depended on the relative phase of the surround. A simple model implementing a linear combination of center and surround modulation fit the measurements well. At the lowest temporal frequency (3.125 Hz), the surround's influence was virtually identical for monocular and dichoptic conditions, suggesting that at this frequency, the surround's influence is mediated primarily by a binocular neural mechanism. At higher frequencies, the surround's influence was greater for the monocular condition than for the dichoptic condition, and this difference increased with temporal frequency. Our findings show that two separate neural mechanisms mediate chromatic contextual interactions: one binocular and dominant at lower temporal frequencies and the other monocular and dominant at higher frequencies (6-10 Hz).

Dichotic beats of mistuned consonances.

PubMed

Feeney, M P

1997-10-01

The beats of mistuned consonances (BMCs) result from the presentation of two sinusoids at frequencies slightly mistuned from a ratio of small integers. Several studies have suggested that the source of dichotic BMCs is an interaction within a binaural critical band. In one case the mechanism has been explained as an aural harmonic of the low-frequency tone (f1) creating binaural beats with the high-frequency tone (f2). The other explanation involves a binaural cross correlation between the excitation pattern of f1 and the contralateral f2--occurring within the binaural critical band centered at f2. This study examined the detection of dichotic BMCs for the octave and fifth. In one experiment with the octave, narrow-band noise centered at f2 was presented to one ear along with f1. The other ear was presented with f2. The noise was used to prevent interactions in the binaural critical band centered at f2. Dichotic BMCs were still detected under these conditions, suggesting that binaural interaction within a critical band does not explain the effect. Localization effects were also observed under this masking condition for phase reversals of tuned dichotic octave stimuli. These findings suggest a new theory of dichotic BMCs as a between-channel phase effect. The modified weighted-image model of localization [Stern and Trahiotis, in Auditory Physiology and Perception, edited by Y. Cazals, L. Demany, and K. Horner (Pergamon, Oxford, 1992), pp. 547-554] was used to provide an explanation of the between-channel mechanism.

Privacy preserving interactive record linkage (PPIRL).

PubMed

Kum, Hye-Chung; Krishnamurthy, Ashok; Machanavajjhala, Ashwin; Reiter, Michael K; Ahalt, Stanley

2014-01-01

Record linkage to integrate uncoordinated databases is critical in biomedical research using Big Data. Balancing privacy protection against the need for high quality record linkage requires a human-machine hybrid system to safely manage uncertainty in the ever changing streams of chaotic Big Data. In the computer science literature, private record linkage is the most published area. It investigates how to apply a known linkage function safely when linking two tables. However, in practice, the linkage function is rarely known. Thus, there are many data linkage centers whose main role is to be the trusted third party to determine the linkage function manually and link data for research via a master population list for a designated region. Recently, a more flexible computerized third-party linkage platform, Secure Decoupled Linkage (SDLink), has been proposed based on: (1) decoupling data via encryption, (2) obfuscation via chaffing (adding fake data) and universe manipulation; and (3) minimum information disclosure via recoding. We synthesize this literature to formalize a new framework for privacy preserving interactive record linkage (PPIRL) with tractable privacy and utility properties and then analyze the literature using this framework. Human-based third-party linkage centers for privacy preserving record linkage are the accepted norm internationally. We find that a computer-based third-party platform that can precisely control the information disclosed at the micro level and allow frequent human interaction during the linkage process, is an effective human-machine hybrid system that significantly improves on the linkage center model both in terms of privacy and utility.

An individual-based modeling approach to simulate the effects of cellular nutrient competition on Escherichia coli K-12 MG1655 colony behavior and interactions in aerobic structured food systems.

PubMed

Tack, Ignace L M M; Logist, Filip; Noriega Fernández, Estefanía; Van Impe, Jan F M

2015-02-01

Traditional kinetic models in predictive microbiology reliably predict macroscopic dynamics of planktonically-growing cell cultures in homogeneous liquid food systems. However, most food products have a semi-solid structure, where microorganisms grow locally in colonies. Individual colony cells exhibit strongly different and non-normally distributed behavior due to local nutrient competition. As a result, traditional models considering average population behavior in a homogeneous system do not describe colony dynamics in full detail. To incorporate local resource competition and individual cell differences, an individual-based modeling approach has been applied to Escherichia coli K-12 MG1655 colonies, considering the microbial cell as modeling unit. The first contribution of this individual-based model is to describe single colony growth under nutrient-deprived conditions. More specifically, the linear and stationary phase in the evolution of the colony radius, the evolution from a disk-like to branching morphology, and the emergence of a starvation zone in the colony center are simulated and compared to available experimental data. These phenomena occur earlier at more severe nutrient depletion conditions, i.e., at lower nutrient diffusivity and initial nutrient concentration in the medium. Furthermore, intercolony interactions have been simulated. Higher inoculum densities lead to stronger intercolony interactions, such as colony merging and smaller colony sizes, due to nutrient competition. This individual-based model contributes to the elucidation of characteristic experimentally observed colony behavior from mechanistic information about cellular physiology and interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Mechanisms of Water Exchange: The Regulatory Roles of Multiple Interactions in Social Wasps.

PubMed

Agrawal, Devanshu; Karsai, Istvan

2016-01-01

Evolutionary benefits of task fidelity and improving information acquisition via multiple transfers of materials between individuals in a task partitioned system have been shown before, but in this paper we provide a mechanistic explanation of these phenomena. Using a simple mathematical model describing the individual interactions of the wasps, we explain the functioning of the common stomach, an information center, which governs construction behavior and task change. Our central hypothesis is a symmetry between foragers who deposit water and foragers who withdraw water into and out of the common stomach. We combine this with a trade-off between acceptance and resistance to water transfer. We ultimately derive a mathematical function that relates the number of interactions that foragers complete with common stomach wasps during a foraging cycle. We use field data and additional model assumptions to calculate values of our model parameters, and we use these to explain why the fullness of the common stomach stabilizes just below 50 percent, why the average number of successful interactions between foragers and the wasps forming the common stomach is between 5 and 7, and why there is a variation in this number of interactions over time. Our explanation is that our proposed water exchange mechanism places natural bounds on the number of successful interactions possible, water exchange is set to optimize mediation of water through the common stomach, and the chance that foragers abort their task prematurely is very low.

The Mechanisms of Water Exchange: The Regulatory Roles of Multiple Interactions in Social Wasps

PubMed Central

Agrawal, Devanshu; Karsai, Istvan

2016-01-01

Evolutionary benefits of task fidelity and improving information acquisition via multiple transfers of materials between individuals in a task partitioned system have been shown before, but in this paper we provide a mechanistic explanation of these phenomena. Using a simple mathematical model describing the individual interactions of the wasps, we explain the functioning of the common stomach, an information center, which governs construction behavior and task change. Our central hypothesis is a symmetry between foragers who deposit water and foragers who withdraw water into and out of the common stomach. We combine this with a trade-off between acceptance and resistance to water transfer. We ultimately derive a mathematical function that relates the number of interactions that foragers complete with common stomach wasps during a foraging cycle. We use field data and additional model assumptions to calculate values of our model parameters, and we use these to explain why the fullness of the common stomach stabilizes just below 50 percent, why the average number of successful interactions between foragers and the wasps forming the common stomach is between 5 and 7, and why there is a variation in this number of interactions over time. Our explanation is that our proposed water exchange mechanism places natural bounds on the number of successful interactions possible, water exchange is set to optimize mediation of water through the common stomach, and the chance that foragers abort their task prematurely is very low. PMID:26751076

Effects of the Caregiver Interaction Profile Training on Caregiver-Child Interactions in Dutch Child Care Centers: A Randomized Controlled Trial.

PubMed

Helmerhorst, Katrien O W; Riksen-Walraven, J Marianne A; Fukkink, Ruben G; Tavecchio, Louis W C; Gevers Deynoot-Schaub, Mirjam J J M

2017-01-01

Previous studies underscore the need to improve caregiver-child interactions in early child care centers. In this study we used a randomized controlled trial to examine whether a 5-week video feedback training can improve six key interactive skills of caregivers in early child care centers: Sensitive responsiveness, respect for autonomy, structuring and limit setting, verbal communication, developmental stimulation, and fostering positive peer interactions. A total of 139 caregivers from 68 early child care groups for 0- to 4-year-old children in Dutch child care centers participated in this RCT, 69 in the intervention condition and 70 in the control condition. Caregiver interactive skills during everyday interactions with the children were rated from videotape using the Caregiver Interaction Profile (CIP) scales at pretest, posttest, and follow-up 3 months after the posttest. Results at posttest indicate a significant positive training effect on all six caregiver interactive skills. Effect sizes of the CIP training range between d  = 0.35 and d  = 0.79. Three months after the posttest, caregivers in the intervention group still scored significantly higher on sensitive responsiveness, respect for autonomy, verbal communication, and fostering positive peer interactions than caregivers in the control group with effect sizes ranging between d  = 0.47 and d  = 0.70. This study shows that the quality of caregiver-child interactions can be improved for all six important caregiver skills, with a relatively short training program. Possible ways to further improve the training and to implement it in practice and education are discussed.

Modeling, Analysis and Simulation Approaches Used in Development of the National Aeronautics and Space Administration Max Launch Abort System

NASA Technical Reports Server (NTRS)

Yuchnovicz, Daniel E.; Dennehy, Cornelius J.; Schuster, David M.

2011-01-01

The National Aeronautics and Space Administration (NASA) Engineering and Safety Center was chartered to develop an alternate launch abort system (LAS) as risk mitigation for the Orion Project. Its successful flight test provided data for the design of future LAS vehicles. Design of the flight test vehicle (FTV) and pad abort trajectory relied heavily on modeling and simulation including computational fluid dynamics for vehicle aero modeling, 6-degree-of-freedom kinematics models for flight trajectory modeling, and 3-degree-of-freedom kinematics models for parachute force modeling. This paper highlights the simulation techniques and the interaction between the aerodynamics, flight mechanics, and aerodynamic decelerator disciplines during development of the Max Launch Abort System FTV.

Who Is Watching and Who Is Playing: Parental Engagement with Children at a Hands-On Science Center

ERIC Educational Resources Information Center

Nadelson, Louis S.

2013-01-01

Family interactions are common phenomenon at visits to science centers and natural history museums. Through interactions the family can support each other as the members individually and collectively learn from their visits. Interaction is particularly important between child(ren) and parent, which may be facilitated by media provided to parents.…

Books, Read-Alouds, and Voluntary Book Interactions: What Do We Know about Centers Serving Three-Year-Olds?

ERIC Educational Resources Information Center

Mesmer, Heidi Anne

2018-01-01

This study examined the quality of books, the quality of read-alouds, and children's voluntary interactions with books in childcare centers serving low-income 3-year-olds (N = 30). Although a large percentage of centers had book areas, the features of book areas differed. The highest percentage of books was highly recommended and appropriate (39%)…

Tenure Eligible/Tenure Track Investigator | Center for Cancer Research

Cancer.gov

The HIV and AIDS Malignancy Branch (HAMB), Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), is a national leader in research in the cancers associated with HIV/AIDS, in the development of therapies for HIV infection, and in oncogenic viruses.  We are seeking a tenure-eligible or tenure-track investigator in the field of HIV–related malignancies or viral oncogenesis.  It is anticipated that the investigator will establish an independent translational research program targeted to the study of the treatment, pathogenesis, and/or prevention of viral-induced or other HIV-associated tumors. The program can be primarily clinical, laboratory-based, or a combination of the two, and can also include animal model studies.  There is the potential to interface with a strong existing clinical research program. Potential areas of focus may include, but are not limited to, therapies for HIV malignancies, including novel immunologic approaches; viral oncogenesis; pathogenesis of HIV-associated malignancies; and virus host interactions, including immunologic interactions. 

Adiabatic Quantum Computation with Neutral Atoms

NASA Astrophysics Data System (ADS)

Biedermann, Grant

2013-03-01

We are implementing a new platform for adiabatic quantum computation (AQC)[2] based on trapped neutral atoms whose coupling is mediated by the dipole-dipole interactions of Rydberg states. Ground state cesium atoms are dressed by laser fields in a manner conditional on the Rydberg blockade mechanism,[3,4] thereby providing the requisite entangling interactions. As a benchmark we study a Quadratic Unconstrained Binary Optimization (QUBO) problem whose solution is found in the ground state spin configuration of an Ising-like model. In collaboration with Lambert Parazzoli, Sandia National Laboratories; Aaron Hankin, Center for Quantum Information and Control (CQuIC), University of New Mexico; James Chin-Wen Chou, Yuan-Yu Jau, Peter Schwindt, Cort Johnson, and George Burns, Sandia National Laboratories; Tyler Keating, Krittika Goyal, and Ivan Deutsch, Center for Quantum Information and Control (CQuIC), University of New Mexico; and Andrew Landahl, Sandia National Laboratories. This work was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories

Stresses due to Squeeze Flow between Particles Surrounded by an Electrolyte Solution with Application to Lithium-Ion Batteries

NASA Astrophysics Data System (ADS)

Conlisk, A. T.; Zhang, Cong

2013-11-01

Large stresses are induced during lithium-ion battery charging and discharging, termed intercalation and deintercalation stresses. Current models of the stresses in lithium-ion batteries in the literature seldom consider the influence of the interaction between the particles within the electrodes on the stress distribution. The particles within lithium-ion battery electrodes can undergo relative motion with relative velocities of different magnitudes and directions. One important mode of motion manifests itself as two particles approaching each other. The interaction is mediated by the electrolyte between the particles. The relative motion of the particles induces significant pressures and the primary objective of this work is to propose a source of mechanical stresses as a consequence of the dynamic squeezing motion as opposed to a static environment considered in the battery literature. Other applications in the biomedical field are also discussed. Supported by DOE Graduate Automotive Technology Education (GATE), OSU Center for Automotive Research and OSU NSEC Center for the Affordable Nanoengineering of Polymeric Biomedical Devices.

Teachers' Promotion or Inhibition of Children's Aggression Depends on Peer-Group Characteristics.

PubMed

Peets, Kätlin; Kikas, Eve

2017-01-01

Researchers have increasingly started to pay attention to how contextual factors, such as the classroom peer context and the quality of student-teacher interactions, influence children's aggressive behavior. This longitudinal study was designed to examine the degree to which benefits and costs of different teaching practices (child-centered and child-dominated) would be dependent on the initial peer-group composition (aggregate levels of aggression and victimization at the beginning of first grade). Teachers provided ratings of aggression and victimization (N = 523 first-grade students; M age at the beginning of first grade = 7.49 years, SD = 0.52). Information about different teaching practices was obtained via observations. Our results show that whereas child-centered practices are beneficial in high-victimization classrooms, child-dominated practices inhibit the development of aggression in low-victimization classroom contexts. Our findings highlight the importance of moving beyond main-effect models to studying how different contextual influences interact to promote, or inhibit, the development of aggression.

ACSYNT - A standards-based system for parametric, computer aided conceptual design of aircraft

NASA Technical Reports Server (NTRS)

Jayaram, S.; Myklebust, A.; Gelhausen, P.

1992-01-01

A group of eight US aerospace companies together with several NASA and NAVY centers, led by NASA Ames Systems Analysis Branch, and Virginia Tech's CAD Laboratory agreed, through the assistance of Americal Technology Initiative, in 1990 to form the ACSYNT (Aircraft Synthesis) Institute. The Institute is supported by a Joint Sponsored Research Agreement to continue the research and development in computer aided conceptual design of aircraft initiated by NASA Ames Research Center and Virginia Tech's CAD Laboratory. The result of this collaboration, a feature-based, parametric computer aided aircraft conceptual design code called ACSYNT, is described. The code is based on analysis routines begun at NASA Ames in the early 1970's. ACSYNT's CAD system is based entirely on the ISO standard Programmer's Hierarchical Interactive Graphics System and is graphics-device independent. The code includes a highly interactive graphical user interface, automatically generated Hermite and B-Spline surface models, and shaded image displays. Numerous features to enhance aircraft conceptual design are described.

Functional and performance requirements of the next NOAA-Kasas City computer system

NASA Technical Reports Server (NTRS)

Mosher, F. R.

1985-01-01

The development of the Advanced Weather Interactive Processing System for the 1990's (AWIPS-90) will result in more timely and accurate forecasts with improved cost effectiveness. As part of the AWIPS-90 initiative, the National Meteorological Center (NMC), the National Severe Storms Forecast Center (NSSFC), and the National Hurricane Center (NHC) are to receive upgrades of interactive processing systems. This National Center Upgrade program will support the specialized inter-center communications, data acquisition, and processing needs of these centers. The missions, current capabilities and general functional requirements for the upgrade to the NSSFC are addressed. System capabilities are discussed along with the requirements for the upgraded system.

Association between social interaction and affect in nursing home residents with dementia.

PubMed

Jao, Ying-Ling; Loken, Eric; MacAndrew, Margaret; Van Haitsma, Kimberly; Kolanowski, Ann

2018-06-01

Social interactions that lead to positive affect are fundamental to human well-being. However, individuals with dementia are challenged to achieve positive social interaction. It is unclear how social interactions influence affect in people with dementia. This study examined the association between social interactions and affect in nursing home residents with dementia. This repeated measures study used baseline data from a clinical trial in which 126 residents from 12 nursing homes were enrolled. Participants were video recorded twice daily on five days. Ratings of social interaction and affect were taken from the videotapes using the Interacting with People subscale of the Passivity in Dementia and the Philadelphia Geriatric Center Apparent Affect Rating Scale. Linear mixed models were used for analysis. Social interaction was significantly related to higher interest and pleasure at within- and between-person levels. Social interaction significantly predicted anxiety and sadness at the between-person level only. Residents with higher cognitive function also displayed greater pleasure. Greater interest and anxiety was evident during the afternoon hours. This study supports the impact of social interactions on positive and negative affect. Findings can guide intervention development, aimed at promoting positive social interactions and improving affect for people with dementia.

Aesthetic perception and its minimal content: a naturalistic perspective

PubMed Central

Xenakis, Ioannis; Arnellos, Argyris

2014-01-01

Aesthetic perception is one of the most interesting topics for philosophers and scientists who investigate how it influences our interactions with objects and states of affairs. Over the last few years, several studies have attempted to determine “how aesthetics is represented in an object,” and how a specific feature of an object could evoke the respective feelings during perception. Despite the vast number of approaches and models, we believe that these explanations do not resolve the problem concerning the conditions under which aesthetic perception occurs, and what constitutes the content of these perceptions. Adopting a naturalistic perspective, we here view aesthetic perception as a normative process that enables agents to enhance their interactions with physical and socio-cultural environments. Considering perception as an anticipatory and preparatory process of detection and evaluation of indications of potential interactions (what we call “interactive affordances”), we argue that the minimal content of aesthetic perception is an emotionally valued indication of interaction potentiality. Aesthetic perception allows an agent to normatively anticipate interaction potentialities, thus increasing sense making and reducing the uncertainty of interaction. This conception of aesthetic perception is compatible with contemporary evidence from neuroscience, experimental aesthetics, and interaction design. The proposed model overcomes several problems of transcendental, art-centered, and objective aesthetics as it offers an alternative to the idea of aesthetic objects that carry inherent values by explaining “the aesthetic” as emergent in perception within a context of uncertain interaction. PMID:25285084

Space shuttle orbiter reaction control system jet interaction study

NASA Technical Reports Server (NTRS)

Rausch, J. R.

1975-01-01

The space shuttle orbiter has forward mounted and rear mounted Reaction Control Systems (RCS) which are used for orbital maneuvering and also provide control during entry and abort maneuvers in the atmosphere. The effects of interaction between the RCS jets and the flow over the vehicle in the atmosphere are studied. Test data obtained in the NASA Langley Research Center 31 inch continuous flow hypersonic tunnel at a nominal Mach number of 10.3 is analyzed. The data were obtained with a 0.01 scale force model with aft mounted RCS nozzles mounted on the sting off of the force model balance. The plume simulations were accomplished primarily using air in a cold gas simulation through scaled nozzles, however, various cold gas mixtures of Helium and Argon were also tested. The effect of number of nozzles was tested as were limited tests of combined controls. The data show that RCS nozzle exit momentum ratio is the primary correlating parameter for effects where the plume impinges on an adjacent surface and mass flow ratio is the parameter where the plume interaction is primarily with the external stream. An analytic model of aft mounted RCS units was developed in which the total reaction control moments are the sum of thrust, impingement, interaction, and cross-coupling terms.

Physics of muscle contraction

NASA Astrophysics Data System (ADS)

Caruel, M.; Truskinovsky, L.

2018-03-01

In this paper we report, clarify and broaden various recent efforts to complement the chemistry-centered models of force generation in (skeletal) muscles by mechanics-centered models. The physical mechanisms of interest can be grouped into two classes: passive and active. The main passive effect is the fast force recovery which does not require the detachment of myosin cross-bridges from actin filaments and can operate without a specialized supply of metabolic fuel (ATP). In mechanical terms, it can be viewed as a collective folding-unfolding phenomenon in the system of interacting bi-stable units and modeled by near equilibrium Langevin dynamics. The active force generation mechanism operates at slow time scales, requires detachment and is crucially dependent on ATP hydrolysis. The underlying mechanical processes take place far from equilibrium and are represented by stochastic models with broken time reversal symmetry implying non-potentiality, correlated noise or multiple reservoirs. The modeling approaches reviewed in this paper deal with both active and passive processes and support from the mechanical perspective the biological point of view that phenomena involved in slow (active) and fast (passive) force generation are tightly intertwined. They reveal, however, that biochemical studies in solution, macroscopic physiological measurements and structural analysis do not provide by themselves all the necessary insights into the functioning of the organized contractile system. In particular, the reviewed body of work emphasizes the important role of long-range interactions and criticality in securing the targeted mechanical response in the physiological regime of isometric contractions. The importance of the purely mechanical micro-scale modeling is accentuated at the end of the paper where we address the puzzling issue of the stability of muscle response on the so called ‘descending limb’ of the isometric tetanus.

Physics of muscle contraction.

PubMed

Caruel, M; Truskinovsky, L

2018-03-01

In this paper we report, clarify and broaden various recent efforts to complement the chemistry-centered models of force generation in (skeletal) muscles by mechanics-centered models. The physical mechanisms of interest can be grouped into two classes: passive and active. The main passive effect is the fast force recovery which does not require the detachment of myosin cross-bridges from actin filaments and can operate without a specialized supply of metabolic fuel (ATP). In mechanical terms, it can be viewed as a collective folding-unfolding phenomenon in the system of interacting bi-stable units and modeled by near equilibrium Langevin dynamics. The active force generation mechanism operates at slow time scales, requires detachment and is crucially dependent on ATP hydrolysis. The underlying mechanical processes take place far from equilibrium and are represented by stochastic models with broken time reversal symmetry implying non-potentiality, correlated noise or multiple reservoirs. The modeling approaches reviewed in this paper deal with both active and passive processes and support from the mechanical perspective the biological point of view that phenomena involved in slow (active) and fast (passive) force generation are tightly intertwined. They reveal, however, that biochemical studies in solution, macroscopic physiological measurements and structural analysis do not provide by themselves all the necessary insights into the functioning of the organized contractile system. In particular, the reviewed body of work emphasizes the important role of long-range interactions and criticality in securing the targeted mechanical response in the physiological regime of isometric contractions. The importance of the purely mechanical micro-scale modeling is accentuated at the end of the paper where we address the puzzling issue of the stability of muscle response on the so called 'descending limb' of the isometric tetanus.

Statistical field theory description of inhomogeneous polarizable soft matter

NASA Astrophysics Data System (ADS)

Martin, Jonathan M.; Li, Wei; Delaney, Kris T.; Fredrickson, Glenn H.

2016-10-01

We present a new molecularly informed statistical field theory model of inhomogeneous polarizable soft matter. The model is based on fluid elements, referred to as beads, that can carry a net monopole of charge at their center of mass and a fixed or induced dipole through a Drude-type distributed charge approach. The beads are thus polarizable and naturally manifest attractive van der Waals interactions. Beyond electrostatic interactions, beads can be given soft repulsions to sustain fluid phases at arbitrary densities. Beads of different types can be mixed or linked into polymers with arbitrary chain models and sequences of charged and uncharged beads. By such an approach, it is possible to construct models suitable for describing a vast range of soft-matter systems including electrolyte and polyelectrolyte solutions, ionic liquids, polymerized ionic liquids, polymer blends, ionomers, and block copolymers, among others. These bead models can be constructed in virtually any ensemble and converted to complex-valued statistical field theories by Hubbard-Stratonovich transforms. One of the fields entering the resulting theories is a fluctuating electrostatic potential; other fields are necessary to decouple non-electrostatic interactions. We elucidate the structure of these field theories, their consistency with macroscopic electrostatic theory in the absence and presence of external electric fields, and the way in which they embed van der Waals interactions and non-uniform dielectric properties. Their suitability as a framework for computational studies of heterogeneous soft matter systems using field-theoretic simulation techniques is discussed.

Statistical field theory description of inhomogeneous polarizable soft matter.

PubMed

Martin, Jonathan M; Li, Wei; Delaney, Kris T; Fredrickson, Glenn H

2016-10-21

We present a new molecularly informed statistical field theory model of inhomogeneous polarizable soft matter. The model is based on fluid elements, referred to as beads, that can carry a net monopole of charge at their center of mass and a fixed or induced dipole through a Drude-type distributed charge approach. The beads are thus polarizable and naturally manifest attractive van der Waals interactions. Beyond electrostatic interactions, beads can be given soft repulsions to sustain fluid phases at arbitrary densities. Beads of different types can be mixed or linked into polymers with arbitrary chain models and sequences of charged and uncharged beads. By such an approach, it is possible to construct models suitable for describing a vast range of soft-matter systems including electrolyte and polyelectrolyte solutions, ionic liquids, polymerized ionic liquids, polymer blends, ionomers, and block copolymers, among others. These bead models can be constructed in virtually any ensemble and converted to complex-valued statistical field theories by Hubbard-Stratonovich transforms. One of the fields entering the resulting theories is a fluctuating electrostatic potential; other fields are necessary to decouple non-electrostatic interactions. We elucidate the structure of these field theories, their consistency with macroscopic electrostatic theory in the absence and presence of external electric fields, and the way in which they embed van der Waals interactions and non-uniform dielectric properties. Their suitability as a framework for computational studies of heterogeneous soft matter systems using field-theoretic simulation techniques is discussed.

Cluster-collision frequency. I. The long-range intercluster potential

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

Amadon, A.S.; Marlow, W.H.

1991-05-15

In recent years, gas-borne atomic and molecular clusters have emerged as subjects of basic physical and chemical interest and are gaining recognition for their importance in numerous applications. To calculate the evolution of the mass distribution of these clusters, their thermal collision rates are required. For computing these collision rates, the long-range interaction energy between clusters is required and is the subject of this paper. Utilizing a formulation of the iterated van der Waals interaction over discrete molecules that can be shown to converge with increasing numbers of atoms to the Lifshitz--van der Waals interaction for condensed matter, we calculatemore » the interaction energy as a function of center-of-mass separation for identical pairs of clusters of 13, 33, and 55 molecules of carbon tetrachloride in icosahedral and dodecahedral configurations. Two different relative orientations are chosen for each pair of clusters, and the energies are compared with energies calculated from the standard formula for continuum matter derived by summing over pair interactions with the Hamaker constant calculated according to Lifshitz theory. The results of these calculations give long-range interaction energies that assume typical adhesion-type values at cluster contact, unlike the unbounded results for the Lifshitz-Hamaker model. The relative difference between the discrete molecular energies and the continuum energies vanishes for {ital r}{sup *}{approx}2, where {ital r}{sup *} is the center-of-mass separation distance in units of cluster diameter. For larger separations, the relative difference changes sign, showing a value of approximately 15%, with the difference diminishing for increasing-sized clusters.« less

Micro-Level Adaptation, Macro-Level Selection, and the Dynamics of Market Partitioning

PubMed Central

García-Díaz, César; van Witteloostuijn, Arjen; Péli, Gábor

2015-01-01

This paper provides a micro-foundation for dual market structure formation through partitioning processes in marketplaces by developing a computational model of interacting economic agents. We propose an agent-based modeling approach, where firms are adaptive and profit-seeking agents entering into and exiting from the market according to their (lack of) profitability. Our firms are characterized by large and small sunk costs, respectively. They locate their offerings along a unimodal demand distribution over a one-dimensional product variety, with the distribution peak constituting the center and the tails standing for the peripheries. We found that large firms may first advance toward the most abundant demand spot, the market center, and release peripheral positions as predicted by extant dual market explanations. However, we also observed that large firms may then move back toward the market fringes to reduce competitive niche overlap in the center, triggering nonlinear resource occupation behavior. Novel results indicate that resource release dynamics depend on firm-level adaptive capabilities, and that a minimum scale of production for low sunk cost firms is key to the formation of the dual structure. PMID:26656107

A teaching skills assessment tool inspired by the Calgary-Cambridge model and the patient-centered approach.

PubMed

Sommer, Johanna; Lanier, Cédric; Perron, Noelle Junod; Nendaz, Mathieu; Clavet, Diane; Audétat, Marie-Claude

2016-04-01

The aim of this study was to develop a descriptive tool for peer review of clinical teaching skills. Two analogies framed our research: (1) between the patient-centered and the learner-centered approach; (2) between the structures of clinical encounters (Calgary-Cambridge communication model) and teaching sessions. During the course of one year, each step of the action research was carried out in collaboration with twelve clinical teachers from an outpatient general internal medicine clinic and with three experts in medical education. The content validation consisted of a literature review, expert opinion and the participatory research process. Interrater reliability was evaluated by three clinical teachers coding thirty audiotaped standardized learner-teacher interactions. This tool contains sixteen items covering the process and content of clinical supervisions. Descriptors define the expected teaching behaviors for three levels of competence. Interrater reliability was significant for eleven items (Kendall's coefficient p<0.05). This peer assessment tool has high reliability and can be used to facilitate the acquisition of teaching skills. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Micro-Level Adaptation, Macro-Level Selection, and the Dynamics of Market Partitioning.

PubMed

García-Díaz, César; van Witteloostuijn, Arjen; Péli, Gábor

2015-01-01

This paper provides a micro-foundation for dual market structure formation through partitioning processes in marketplaces by developing a computational model of interacting economic agents. We propose an agent-based modeling approach, where firms are adaptive and profit-seeking agents entering into and exiting from the market according to their (lack of) profitability. Our firms are characterized by large and small sunk costs, respectively. They locate their offerings along a unimodal demand distribution over a one-dimensional product variety, with the distribution peak constituting the center and the tails standing for the peripheries. We found that large firms may first advance toward the most abundant demand spot, the market center, and release peripheral positions as predicted by extant dual market explanations. However, we also observed that large firms may then move back toward the market fringes to reduce competitive niche overlap in the center, triggering nonlinear resource occupation behavior. Novel results indicate that resource release dynamics depend on firm-level adaptive capabilities, and that a minimum scale of production for low sunk cost firms is key to the formation of the dual structure.

Regional Scale/Regional Climate Model Development and Its Applications at Goddard

NASA Technical Reports Server (NTRS)

Tao, W.-K.; Lau, W.; Qian, J.; Jia, Y.; Wetzel, P.; Chou, M.-D.; Wang, Y.; Lynn, B.

2000-01-01

A Regional Land-Atmosphere Climate Simulation System (RELACS) is being developed and implemented at NASA Goddard Space Flight Center. One of the major goals of RELACS is to use a regional scale model (Penn State/NCAR MM5) with improved physical processes and in particular land-related processes, to understand the role of the land surface and its interaction with convection and radiation as well as the water/energy cycles in the Indo-China/South China Sea (SCS)/China, N. America and S. America region.

Modelling of industrial robot in LabView Robotics

NASA Astrophysics Data System (ADS)

Banas, W.; Cwikła, G.; Foit, K.; Gwiazda, A.; Monica, Z.; Sekala, A.

2017-08-01

Currently can find many models of industrial systems including robots. These models differ from each other not only by the accuracy representation parameters, but the representation range. For example, CAD models describe the geometry of the robot and some even designate a mass parameters as mass, center of gravity, moment of inertia, etc. These models are used in the design of robotic lines and sockets. Also systems for off-line programming use these models and many of them can be exported to CAD. It is important to note that models for off-line programming describe not only the geometry but contain the information necessary to create a program for the robot. Exports from CAD to off-line programming system requires additional information. These models are used for static determination of reachability points, and testing collision. It’s enough to generate a program for the robot, and even check the interaction of elements of the production line, or robotic cell. Mathematical models allow robots to study the properties of kinematic and dynamic of robot movement. In these models the geometry is not so important, so are used only selected parameters such as the length of the robot arm, the center of gravity, moment of inertia. These parameters are introduced into the equations of motion of the robot and motion parameters are determined.

Energy Weighted Angular Correlations Between Hadrons Produced in Electron-Positron Annihilation.

NASA Astrophysics Data System (ADS)

Strharsky, Roger Joseph

Electron-positron annihilation at large center of mass energy produces many hadronic particles. Experimentalists then measure the energies of these particles in calorimeters. This study investigated correlations between the angular locations of one or two such calorimeters and the angular orientation of the electron beam in the laboratory frame of reference. The calculation of these correlations includes weighting by the fraction of the total center of mass energy which the calorimeter measures. Starting with the assumption that the reaction proceeeds through the intermediate production of a single quark/anti-quark pair, a simple statistical model was developed to provide a phenomenological description of the distribution of final state hadrons. The model distributions were then used to calculate the one- and two-calorimeter correlation functions. Results of these calculations were compared with available data and several predictions were made for those quantities which had not yet been measured. Failure of the model to reproduce all of the data was discussed in terms of quantum chromodynamics, a fundamental theory which includes quark interactions.

Implementing the IT Infrastructure for Health Reform: Adoption of Health IT among Patient-Centered Medical Home Practices

PubMed Central

Adler-Milstein, Julia; Cohen, Genna R.

2013-01-01

While health IT is thought to be critical to the success of new models of care delivery, we know little about the extent to which those pursuing these models are relying on HIT. We studied a large patient-centered medical home (PCMH) demonstration project, a new model of care delivery that has received substantial policy attention, in order to assess which types of HIT were most widely used, and how adoption rates changed over time as PCMH practices matured. We found that clinically-focused HIT tools were both widely adopted, and increasingly adopted, in PCMH practices compared to non-PCMH practices. In contrast, HIT that supports patient-engagement, patient portals and personal health records, was neither in widespread use nor more likely to be adopted over time by PCMH practices compared to other practices. This suggests that these tools may not yet support the types of patient engagement and interactions that PCMH practices seek. PMID:24551318

Atlas of Seasonal Means Simulated by the NSIPP 1 Atmospheric GCM. Volume 17

NASA Technical Reports Server (NTRS)

Suarez, Max J. (Editor); Bacmeister, Julio; Pegion, Philip J.; Schubert, Siegfried D.; Busalacchi, Antonio J. (Technical Monitor)

2000-01-01

This atlas documents the climate characteristics of version 1 of the NASA Seasonal-to-Interannual Prediction Project (NSIPP) Atmospheric General Circulation Model (AGCM). The AGCM includes an interactive land model (the Mosaic scheme), and is part of the NSIPP coupled atmosphere-land-ocean model. The results presented here are based on a 20-year (December 1979-November 1999) "ANIIP-style" integration of the AGCM in which the monthly-mean sea-surface temperature and sea ice are specified from observations. The climate characteristics of the AGCM are compared with the National Centers for Environmental Prediction (NCEP) and the European Center for Medium-Range Weather Forecasting (ECMWF) reanalyses. Other verification data include Special Sensor Microwave/Imager (SSNM) total precipitable water, the Xie-Arkin estimates of precipitation, and Earth Radiation Budget Experiment (ERBE) measurements of short and long wave radiation. The atlas is organized by season. The basic quantities include seasonal mean global maps and zonal and vertical averages of circulation, variance/covariance statistics, and selected physics quantities.

Virtual reality: new method of teaching anorectal and pelvic floor anatomy.

PubMed

Dobson, Howard D; Pearl, Russell K; Orsay, Charles P; Rasmussen, Mary; Evenhouse, Ray; Ai, Zhuming; Blew, Gregory; Dech, Fred; Edison, Marcia I; Silverstein, Jonathan C; Abcarian, Herand

2003-03-01

A clear understanding of the intricate spatial relationships among the structures of the pelvic floor, rectum, and anal canal is essential for the treatment of numerous pathologic conditions. Virtual-reality technology allows improved visualization of three-dimensional structures over conventional media because it supports stereoscopic-vision, viewer-centered perspective, large angles of view, and interactivity. We describe a novel virtual reality-based model designed to teach anorectal and pelvic floor anatomy, pathology, and surgery. A static physical model depicting the pelvic floor and anorectum was created and digitized at 1-mm intervals in a CT scanner. Multiple software programs were used along with endoscopic images to generate a realistic interactive computer model, which was designed to be viewed on a networked, interactive, virtual-reality display (CAVE or ImmersaDesk). A standard examination of ten basic anorectal and pelvic floor anatomy questions was administered to third-year (n = 6) and fourth-year (n = 7) surgical residents. A workshop using the Virtual Pelvic Floor Model was then given, and the standard examination was readministered so that it was possible to evaluate the effectiveness of the Digital Pelvic Floor Model as an educational instrument. Training on the Virtual Pelvic Floor Model produced substantial improvements in the overall average test scores for the two groups, with an overall increase of 41 percent (P = 0.001) and 21 percent (P = 0.0007) for third-year and fourth-year residents, respectively. Resident evaluations after the workshop also confirmed the effectiveness of understanding pelvic anatomy using the Virtual Pelvic Floor Model. This model provides an innovative interactive educational framework that allows educators to overcome some of the barriers to teaching surgical and endoscopic principles based on understanding highly complex three-dimensional anatomy. Using this collaborative, shared virtual-reality environment, teachers and students can interact from locations world-wide to manipulate the components of this model to achieve the educational goals of this project along with the potential for virtual surgery.

The role of stabilization centers in protein thermal stability

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

Magyar, Csaba; Gromiha, M. Michael; Sávoly, Zoltán

2016-02-26

The definition of stabilization centers was introduced almost two decades ago. They are centers of noncovalent long range interaction clusters, believed to have a role in maintaining the three-dimensional structure of proteins by preventing their decay due to their cooperative long range interactions. Here, this hypothesis is investigated from the viewpoint of thermal stability for the first time, using a large protein thermodynamics database. The positions of amino acids belonging to stabilization centers are correlated with available experimental thermodynamic data on protein thermal stability. Our analysis suggests that stabilization centers, especially solvent exposed ones, do contribute to the thermal stabilizationmore » of proteins. - Highlights: • Stabilization centers contribute to thermal stabilization of protein structures. • Stabilization center content correlates with melting temperature of proteins. • Exposed stabilization center content correlates with stability even in hyperthermophiles. • Stability changing mutations are frequently found at stabilization centers.« less

Developing Opportunities for Senior Citizens and 3- and 4-Year-Old Children in a Northeast U.S. Jewish Community Center to Interact.

ERIC Educational Resources Information Center

Weeks, Joyce

Due to changes in society, young children and senior citizens have little opportunity for interaction. This practicum report formulated a plan for intergenerational interaction opportunities between 3- and 4-year-olds and senior citizens at a Jewish community center where separate programs for preschool children and senior citizens typified the…

Patient-centered communication of community treatment assistants in Tanzania predicts coverage of future mass drug administration for trachoma.

PubMed

Jenson, Alexander; Roter, Debra L; Mkocha, Harran; Munoz, Beatriz; West, Sheila

2018-06-01

Prevention of Trachoma, the leading cause of infectious blindness, requires community treatment assistants (CTAs) to perform mass drug administration (MDA) of azithromycin. Previous research has shown that female CTAs have higher MDA coverage, but no studies have focused on the content of conversation. We hypothesize that female CTAs had more patient-centered communication and higher MDA coverage. In 2011, CTAs from 23 distribution sites undergoing MDA as part of the Partnership for Rapid Elimination of Trachoma were selected. CTA - villager interactions were audio recorded. Audio was analyzed using an adaptation of the Roter Interaction Analysis System. The outcome of interest was the proportion of adults receiving MDA in 2011 who returned in 2012. 58 CTAs and 3122 interactions were included. Sites with female CTAs had significantly higher patient-centeredness ratio (0.548 vs 0.400) when compared to sites with male CTAs. Sites with more patient-centered interactions had higher proportion of patients return (p = 0.009). Female CTAs had higher proportion of patient-centered communication. Patient centered communication was associated with higher rates of return for MDA. Greater patient-centered connection with health care providers affects participation in public health efforts, even when those providers are lay health workers. Copyright © 2018 Elsevier B.V. All rights reserved.

Eye center localization and gaze gesture recognition for human-computer interaction.

PubMed

Zhang, Wenhao; Smith, Melvyn L; Smith, Lyndon N; Farooq, Abdul

2016-03-01

This paper introduces an unsupervised modular approach for accurate and real-time eye center localization in images and videos, thus allowing a coarse-to-fine, global-to-regional scheme. The trajectories of eye centers in consecutive frames, i.e., gaze gestures, are further analyzed, recognized, and employed to boost the human-computer interaction (HCI) experience. This modular approach makes use of isophote and gradient features to estimate the eye center locations. A selective oriented gradient filter has been specifically designed to remove strong gradients from eyebrows, eye corners, and shadows, which sabotage most eye center localization methods. A real-world implementation utilizing these algorithms has been designed in the form of an interactive advertising billboard to demonstrate the effectiveness of our method for HCI. The eye center localization algorithm has been compared with 10 other algorithms on the BioID database and six other algorithms on the GI4E database. It outperforms all the other algorithms in comparison in terms of localization accuracy. Further tests on the extended Yale Face Database b and self-collected data have proved this algorithm to be robust against moderate head poses and poor illumination conditions. The interactive advertising billboard has manifested outstanding usability and effectiveness in our tests and shows great potential for benefiting a wide range of real-world HCI applications.

Effects of Passive Porosity on Interacting Vortex Flows At Supersonic Speeds

NASA Technical Reports Server (NTRS)

Erickson, Gary E.

2000-01-01

A wind tunnel experiment was conducted in the NASA Langley Research Center (LaRC) Unitary Plan Wind Tunnel (UPWT) to determine the effects of passive surface porosity on vortex flow interaction about a general research fighter configuration at supersonic speeds. Optical flow measurement and flow visualization techniques were used and included pressure-sensitive paint (PSP), schlieren, and laser vapor screen (LVS) These techniques were combined with force and moment and conventional electronically-scanned pressure (ESP) measurements to quantify and to visualize the effects of flow-through porosity applied to a wing leading-edge extension (LEX) mounted to a 65 deg cropped delta wing model.

Successful model for cooperative student learning centers in physics and astronomy

NASA Astrophysics Data System (ADS)

Bieniek, Ronald J.; Johnson, John A.

2003-04-01

We have established successful problem-based learning centers for introductory courses in physics [1] and astronomy [2] that fully implement the Seven Principles of Good Practice in Undergraduate Education [3] without increased demand on faculty time. Large percentages of students at our two institutions voluntarily utilize these learning venues. Course instructors guide self-forming groups of students to mastery of technical concepts and skills, building greater student self-confidence through direct interaction and feedback. The approach's immediacy helps students recognize ambiguities in their understanding, thereby increasing impact at teachable moments. Underperforming students are assisted along side students who wish to hone their skills. The format also facilitates racial and gender mixing within learning center camaraderie. Specific pedagogical and operational techniques for running learning centers will be presented. [1] http://www.umr.edu/ physics/plc [2] http://astron.berkeley.edu/talc.html [3] A.W. Chickering & Z.F. Gamson, Am. Assoc. Higher Ed. Bulletin, 1987, 39(7) 3-7.

Computer-assisted visual interactive recognition and its prospects of implementation over the Internet

NASA Astrophysics Data System (ADS)

Zou, Jie; Gattani, Abhishek

2005-01-01

When completely automated systems don't yield acceptable accuracy, many practical pattern recognition systems involve the human either at the beginning (pre-processing) or towards the end (handling rejects). We believe that it may be more useful to involve the human throughout the recognition process rather than just at the beginning or end. We describe a methodology of interactive visual recognition for human-centered low-throughput applications, Computer Assisted Visual InterActive Recognition (CAVIAR), and discuss the prospects of implementing CAVIAR over the Internet. The novelty of CAVIAR is image-based interaction through a domain-specific parameterized geometrical model, which reduces the semantic gap between humans and computers. The user may interact with the computer anytime that she considers its response unsatisfactory. The interaction improves the accuracy of the classification features by improving the fit of the computer-proposed model. The computer makes subsequent use of the parameters of the improved model to refine not only its own statistical model-fitting process, but also its internal classifier. The CAVIAR methodology was applied to implement a flower recognition system. The principal conclusions from the evaluation of the system include: 1) the average recognition time of the CAVIAR system is significantly shorter than that of the unaided human; 2) its accuracy is significantly higher than that of the unaided machine; 3) it can be initialized with as few as one training sample per class and still achieve high accuracy; and 4) it demonstrates a self-learning ability. We have also implemented a Mobile CAVIAR system, where a pocket PC, as a client, connects to a server through wireless communication. The motivation behind a mobile platform for CAVIAR is to apply the methodology in a human-centered pervasive environment, where the user can seamlessly interact with the system for classifying field-data. Deploying CAVIAR to a networked mobile platform poses the challenge of classifying field images and programming under constraints of display size, network bandwidth, processor speed, and memory size. Editing of the computer-proposed model is performed on the handheld while statistical model fitting and classification take place on the server. The possibility that the user can easily take several photos of the object poses an interesting information fusion problem. The advantage of the Internet is that the patterns identified by different users can be pooled together to benefit all peer users. When users identify patterns with CAVIAR in a networked setting, they also collect training samples and provide opportunities for machine learning from their intervention. CAVIAR implemented over the Internet provides a perfect test bed for, and extends, the concept of Open Mind Initiative proposed by David Stork. Our experimental evaluation focuses on human time, machine and human accuracy, and machine learning. We devoted much effort to evaluating the use of our image-based user interface and on developing principles for the evaluation of interactive pattern recognition system. The Internet architecture and Mobile CAVIAR methodology have many applications. We are exploring in the directions of teledermatology, face recognition, and education.

Introducing the Postsecondary Instructional Practices Survey (PIPS): A Concise, Interdisciplinary, and Easy-to-Score Survey

PubMed Central

Walter, Emily M.; Henderson, Charles R.; Beach, Andrea L.; Williams, Cody T.

2016-01-01

Researchers, administrators, and policy makers need valid and reliable information about teaching practices. The Postsecondary Instructional Practices Survey (PIPS) is designed to measure the instructional practices of postsecondary instructors from any discipline. The PIPS has 24 instructional practice statements and nine demographic questions. Users calculate PIPS scores by an intuitive proportion-based scoring convention. Factor analyses from 72 departments at four institutions (N = 891) support a 2- or 5-factor solution for the PIPS; both models include all 24 instructional practice items and have good model fit statistics. Factors in the 2-factor model include (a) instructor-centered practices, nine items; and (b) student-centered practices, 13 items. Factors in the 5-factor model include (a) student–student interactions, six items; (b) content delivery, four items; (c) formative assessment, five items; (d) student-content engagement, five items; and (e) summative assessment, four items. In this article, we describe our development and validation processes, provide scoring conventions and outputs for results, and describe wider applications of the instrument. PMID:27810868

Investigations of the 0.020-scale 88-OTS Integrated Space Shuttle Vehicle Jet-Plume Model in the NASA/Ames Research Center 11 by11-Foot Unitary Plan Wind Tunnel (IA80). Volume 1

NASA Technical Reports Server (NTRS)

Nichols, M. E.

1976-01-01

The results are documented of jet plume effects wind tunnel test of the 0.020-scale 88-OTS launch configuration space shuttle vehicle model in the 11 x 11 foot leg of the NASA/Ames Research Center Unitary Plan Wind Tunnel. This test involved cold gas main propulsion system (MPS) and solid rocket motor (SRB) plume simulations at Mach numbers from 0.6 to 1.4. Integrated vehicle surface pressure distributions, elevon and rudder hinge moments, and wing and vertical tail root bending and torsional moments due to MPS and SRB plume interactions were determined. Nozzle power conditions were controlled per pretest nozzle calibrations. Model angle of attack was varied from -4 deg to +4 deg; model angle of sideslip was varied from -4 deg to +4 deg. Reynolds number was varied for certain test conditions and configurations, with the nominal freestream total pressure being 14.69 psia. Plotted force and pressure data are presented.

Arsenic-gene interactions and beta-cell function in the Strong Heart Family Study.

PubMed

Balakrishnan, Poojitha; Navas-Acien, Ana; Haack, Karin; Vaidya, Dhananjay; Umans, Jason G; Best, Lyle G; Goessler, Walter; Francesconi, Kevin A; Franceschini, Nora; North, Kari E; Cole, Shelley A; Voruganti, V Saroja; Gribble, Matthew O

2018-06-01

We explored arsenic-gene interactions influencing pancreatic beta-cell activity in the Strong Heart Family Study (SHFS). We considered 42 variants selected for associations with either beta-cell function (31 variants) or arsenic metabolism (11 variants) in the SHFS. Beta-cell function was calculated as homeostatic model - beta corrected for insulin resistance (cHOMA-B) by regressing homeostatic model - insulin resistance (HOMA-IR) on HOMA-B and adding mean HOMA-B. Arsenic exposure was dichotomized at the median of the sum of creatinine-corrected inorganic and organic arsenic species measured by high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS). Additive GxE models for cHOMA-B were adjusted for age and ancestry, and accounted for family relationships. Models were stratified by center (Arizona, Oklahoma, North Dakota and South Dakota) and meta-analyzed. The two interactions between higher vs. lower arsenic and SNPs for cHOMA-B that were nominally significant at P < 0.05 were with rs10738708 (SNP overall effect -3.91, P = 0.56; interaction effect with arsenic -31.14, P = 0.02) and rs4607517 (SNP overall effect +16.61, P = 0.03; interaction effect with arsenic +27.02, P = 0.03). The corresponding genes GCK and TUSC1 suggest oxidative stress and apoptosis as possible mechanisms for arsenic impacts on beta-cell function. No interactions were Bonferroni-significant (1.16 × 10 -3 ). Our findings are suggestive of oligogenic moderation of arsenic impacts on pancreatic β-cell endocrine function, but were not Bonferroni-significant. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of reaction control system jet simulation on the stability and control characteristics of a 0.015-scale space shuttle orbiter model in the Ames Research Center 3.5-foot hypersonic wind tunnel

NASA Technical Reports Server (NTRS)

Dziubala, T. J.; Marroquin, J.; Cleary, J. W.; Mellenthin, J. A.

1973-01-01

An experimental investigation was performed in the Ames Research Center 3.5-Foot Hypersonic Wind Tunnel to obtain detailed effects which interactions between the RCS jet flow field and the local orbiter flow field have on orbiter hypersonic stability and control characteristics. Six-component force data were obtained through an angle-of-attack range of 15 to 35 deg with 0 deg angle of sideslip. The test was conducted with yaw, pitch and roll jet simulation at a free-stream Mach number of 10.3. These data simulate two SSV reentry flight conditions at Mach numbers of 28.3 and 10.3. Fuselage base pressures and pressures on the nonmetric RCS pods were obtained in addition to the basic force measurements. Model 42-0 was used for these tests.

Performance optimization of helicopter rotor blades

NASA Technical Reports Server (NTRS)

Walsh, Joanne L.

1991-01-01

As part of a center-wide activity at NASA Langley Research Center to develop multidisciplinary design procedures by accounting for discipline interactions, a performance design optimization procedure is developed. The procedure optimizes the aerodynamic performance of rotor blades by selecting the point of taper initiation, root chord, taper ratio, and maximum twist which minimize hover horsepower while not degrading forward flight performance. The procedure uses HOVT (a strip theory momentum analysis) to compute the horse power required for hover and the comprehensive helicopter analysis program CAMRAD to compute the horsepower required for forward flight and maneuver. The optimization algorithm consists of the general purpose optimization program CONMIN and approximate analyses. Sensitivity analyses consisting of derivatives of the objective function and constraints are carried out by forward finite differences. The procedure is applied to a test problem which is an analytical model of a wind tunnel model of a utility rotor blade.

A Historical Perspective on Dynamics Testing at the Langley Research Center

NASA Technical Reports Server (NTRS)

Horta, Lucas G.; Kvaternik, Raymond G.

2000-01-01

The history of structural dynamics testing research over the past four decades at the Langley Research Center of the National Aeronautics and Space Administration is reviewed. Beginning in the early sixties, Langley investigated several scale model and full-scale spacecraft including the NIMBUS and various concepts for Apollo and Viking landers. Langley engineers pioneered the use of scaled models to study the dynamics of launch vehicles including Saturn I, Saturn V, and Titan III. In the seventies, work emphasized the Space Shuttle and advanced test and data analysis methods. In the eighties, the possibility of delivering large structures to orbit by the Space Shuttle shifted focus towards understanding the interaction of flexible space structures with attitude control systems. Although Langley has maintained a tradition of laboratory-based research, some flight experiments were supported. This review emphasizes work that, in some way, advanced the state of knowledge at the time.

Exploring clouds, weather, climate, and modeling using bilingual content and activities from the Windows to the Universe program and the Center for Multiscale Modeling of Atmospheric Processes

NASA Astrophysics Data System (ADS)

Foster, S. Q.; Johnson, R. M.; Randall, D.; Denning, S.; Russell, R.; Gardiner, L.; Hatheway, B.; Genyuk, J.; Bergman, J.

2008-12-01

The need for improving the representation of cloud processes in climate models has been one of the most important limitations of the reliability of climate-change simulations. Now in its third year, the National Science Foundation-funded Center for Multi-scale Modeling of Atmospheric Processes (CMMAP) at Colorado State University is addressing this problem through a revolutionary new approach to representing cloud processes on their native scales, including the cloud-scale interaction processes that are active in cloud systems. CMMAP has set ambitious education and human-resource goals to share basic information about the atmosphere, clouds, weather, climate, and modeling with diverse K-12 and public audiences through its affiliation with the Windows to the Universe (W2U) program at University Corporation for Atmospheric Research (UCAR). W2U web pages are written at three levels in English and Spanish. This information targets learners at all levels, educators, and families who seek to understand and share resources and information about the nature of weather and the climate system, and career role models from related research fields. This resource can also be helpful to educators who are building bridges in the classroom between the sciences, the arts, and literacy. Visitors to the W2U's CMMAP web portal can access a beautiful new clouds image gallery; information about each cloud type and the atmospheric processes that produce them; a Clouds in Art interactive; collections of weather-themed poetry, art, and myths; links to games and puzzles for children; and extensive classroom- ready resources and activities for K-12 teachers. Biographies of CMMAP scientists and graduate students are featured. Basic science concepts important to understanding the atmosphere, such as condensation, atmosphere pressure, lapse rate, and more have been developed, as well as 'microworlds' that enable students to interact with experimental tools while building fundamental knowledge. These resources can be accessed online at no cost by the entire atmospheric science K-12 and informal science education community.

Ammonia Adsorption and Co-adsorption with Water in HKUST-1: Spectroscopic Evidence for Cooperative Interactions

DOE PAGES

Nijem, Nour; Fürsich, Katrin; Bluhm, Hendrik; ...

2015-10-09

Ammonia interactions and competition with water at the interface of nanoporous metal organic framework thin films of HKUST-1 (Cu 3Btc 2 , Btc = 1,3,5-benzenedicarboxylate) are investigated with ambient pressure X-ray photoelectron spectroscopy (APXPS). In the absence of water, ammonia adsorption at the Cu 2+ metal center weakens the metal-linker bond of the framework. In the presence of water, due to the higher binding energy (adsorption strength) of ammonia compared to water, ammonia replaces water at the unsaturated Cu 2+ metal centers. The water molecules remaining in the pores are stabilized by hydrogen bonding to ammonia. Hydrogen bonding between themore » water and ammonia strengthens the metal-ammonia interaction due to cooperative interactions. Cooperative interactions result in a reduction in the metal center oxidation state facilitating linker replacement by other species explaining the previously reported structure degradation.« less

Ammonia Adsorption and Co-adsorption with Water in HKUST-1: Spectroscopic Evidence for Cooperative Interactions

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

Nijem, Nour; Fürsich, Katrin; Bluhm, Hendrik

Ammonia interactions and competition with water at the interface of nanoporous metal organic framework thin films of HKUST-1 (Cu 3Btc 2 , Btc = 1,3,5-benzenedicarboxylate) are investigated with ambient pressure X-ray photoelectron spectroscopy (APXPS). In the absence of water, ammonia adsorption at the Cu 2+ metal center weakens the metal-linker bond of the framework. In the presence of water, due to the higher binding energy (adsorption strength) of ammonia compared to water, ammonia replaces water at the unsaturated Cu 2+ metal centers. The water molecules remaining in the pores are stabilized by hydrogen bonding to ammonia. Hydrogen bonding between themore » water and ammonia strengthens the metal-ammonia interaction due to cooperative interactions. Cooperative interactions result in a reduction in the metal center oxidation state facilitating linker replacement by other species explaining the previously reported structure degradation.« less

A Retrospective Evaluation of Remote Pharmacist Interventions in a Telepharmacy Service Model Using a Conceptual Framework

PubMed Central

Murante, Lori J.; Moffett, Lisa M.

2014-01-01

Abstract Objectives: This retrospective cross-sectional study evaluated a telepharmacy service model using a conceptual framework to compare documented remote pharmacist interventions by year, hospital, and remote pharmacist and across rural hospitals with or without an on-site rural hospital pharmacist. Materials and Methods: Documented remote pharmacist interventions for patients at eight rural hospitals in the Midwestern United States during prospective prescription order review/entry from 2008 to 2011 were extracted from RxFusion® database (a home-grown system, i.e., internally developed program at The Nebraska Medical Center (TNMC) for capturing remote pharmacist-documented intervention data). The study authors conceptualized an analytical framework, mapping the 37 classes of remote pharmacist interventions to three broader-level definitions: (a) intervention, eight categories (interaction/potential interaction, contraindication, adverse effects, anticoagulation monitoring, drug product selection, drug regimen, summary, and recommendation), (b) patient medication management, two categories (therapy review and action), and (c) health system-centered medication use process, four categories (prescribing, transcribing and documenting, administering, and monitoring). Frequencies of intervention levels were compared by year, hospital, remote pharmacist, and hospital pharmacy status (with a remote pharmacist and on-site pharmacist or with a remote pharmacist only) using chi-squared test and univariate logistic regression analyses, as appropriate. Results: For 450,000 prescription orders 19,222 remote pharmacist interventions were documented. Frequency of interventions significantly increased each year (36% in 2009, 55% in 2010, and 7% in 2011) versus the baseline year (2008, 3%) when service started. The frequency of interventions also differed significantly across the eight hospitals and 16 remote pharmacists for the three defined intervention levels and categories. Remote pharmacist interventions at hospitals with an on-site and remote pharmacist (n=12,141) versus those with a remote pharmacist alone (n=7,081) were significantly more likely to be (1) patient-centered, (2) related to “actionable” medication management recommendations (unadjusted odds ratio [OR]=1.12), and (3) related to the “transcribing” (OR=1.47) and “prescribing” (OR=1.40) steps of the health system-centered medication use process level (all p<0.01). Conclusions: This is one of the first studies to demonstrate the patient- and health system-centered nature of pharmaceutical care delivered via a telepharmacy service model by evaluating documented remote pharmacist interventions with an analytical framework. PMID:24611489

Response Surface Methodology: 1966-1986

DTIC Science & Technology

1986-09-01

reviews criteria from which choices of design parameters in (i) can be made; for example, the choice of a composite...fact that, in ý13 this case, all design points are at a distance p = - from the design center, and no control is ex- erted on Var y(,k) at a distance...interactions in the second order model. The notion of "small’ composite results from the fact that additional information on

A Simulation Base Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

2017-01-01

NASA's human space program has developed considerable experience with near Earth space operations. Although NASA has experience with deep space robotic missions, NASA has little substantive experience with human deep space operations. Even in the Apollo program, the missions lasted only a few weeks and the communication latencies were on the order of seconds. Human missions beyond the relatively close confines of the Earth-Moon system will involve missions with durations measured in months and communications latencies measured in minutes. To minimize crew risk and to maximize mission success, NASA needs to develop a better understanding of the implications of these types of mission durations and communication latencies on vehicle design, mission design and flight controller interaction with the crew. To begin to address these needs, NASA performed a study using a physics-based subsystem simulation to investigate the interactions between spacecraft crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation, built with a subsystem modeling tool developed at NASA's Johnson Space Center, models the life support system of a Mars transit vehicle. The simulation contains models of the cabin atmosphere and pressure control system, electrical power system, drinking and waste water systems, internal and external thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the vehicle subsystems; 2) a mission control center interface with data transport delays up to 15 minutes each way; 3) a real-time simulation test conductor interface that can be use to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission between July 18th and Aug 3rd of year 2016. The NEEMO mission provides ideal conditions for this study with crew in the loop, an active control center, and real-time flow of high latency communications and data. NEEMO crew and ground support will work through procedures including activation of the transit vehicle power system, opening the hatch between the transit vehicle and a Mars ascent vehicle, transferring simulated crewmembers between vehicles, overcoming subsystem malfunctions, sending simulated crewmember on extra-vehicular activities, and other housekeeping activities. This study is enhancing the understanding of high latency operations and the advantages and disadvantages of different communication methods. It is also providing results that will help improve the design of simulation interfaces and inform the design of Mars transit vehicles.

Condensate oscillations in a Penrose tiling lattice

NASA Astrophysics Data System (ADS)

Akdeniz, Z.; Vignolo, P.

2017-07-01

We study the dynamics of a Bose-Einstein condensate subject to a particular Penrose tiling lattice. In such a lattice, the potential energy at each site depends on the neighbour sites, accordingly to the model introduced by Sutherland [16]. The Bose-Einstein wavepacket, initially at rest at the lattice symmetry center, is released. We observe a very complex time-evolution that strongly depends on the symmetry center (two choices are possible), on the potential energy landscape dispersion, and on the interaction strength. The condensate-width oscillates at different frequencies and we can identify large-frequency reshaping oscillations and low-frequency rescaling oscillations. We discuss in which conditions these oscillations are spatially bounded, denoting a self-trapping dynamics.

Public reproductive health and 'unintended' pregnancies: introducing the construct 'supportability'.

PubMed

Macleod, Catriona Ida

2016-09-01

In this Perspectives paper, I outline the limitations of the concept of 'intentionality' in public reproductive health understandings of pregnancy. 'Intentionality', 'plannedness', 'wantedness' and 'timing' place individual cognitions, psychology and/or behaviors at the center of public health conceptualizations of pregnancies, thereby leaving the underlying social and structural dynamics under-examined. I propose a model that places 'supportability' at the center of thinking about pregnancies and that allows for an analysis of the intersection of individual cognitions, emotions and behavior with micro-level interactive spaces and macro-level issues. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Electric Propulsion Interactions Code (EPIC): Recent Enhancements and Goals for Future Capabilities

NASA Technical Reports Server (NTRS)

Gardner, Barbara M.; Kuharski, Robert A.; Davis, Victoria A.; Ferguson, Dale C.

2007-01-01

The Electric Propulsion Interactions Code (EPIC) is the leading interactive computer tool for assessing the effects of electric thruster plumes on spacecraft subsystems. EPIC, developed by SAIC under the sponsorship of the Space Environments and Effects (SEE) Program at the NASA Marshall Space Flight Center, has three primary modules. One is PlumeTool, which calculates plumes of electrostatic thrusters and Hall-effect thrusters by modeling the primary ion beam as well as elastic scattering and charge-exchange of beam ions with thruster-generated neutrals. ObjectToolkit is a 3-D object definition and spacecraft surface modeling tool developed for use with several SEE Program codes. The main EPIC interface integrates the thruster plume into the 3-D geometry of the spacecraft and calculates interactions and effects of the plume with the spacecraft. Effects modeled include erosion of surfaces due to sputtering, re-deposition of sputtered materials, surface heating, torque on the spacecraft, and changes in surface properties due to erosion and deposition. In support of Prometheus I (JIMO), a number of new capabilities and enhancements were made to existing EPIC models. Enhancements to EPIC include adding the ability to scale and view individual plume components, to import a neutral plume associated with a thruster (to model a grid erosion plume, for example), and to calculate the plume from new initial beam conditions. Unfortunately, changes in program direction have left a number of desired enhancements undone. Variable gridding over a surface and resputtering of deposited materials, including multiple bounces and sticking coefficients, would significantly enhance the erosion/deposition model. Other modifications such as improving the heating model and the PlumeTool neutral plume model, enabling time dependent surface interactions, and including EM1 and optical effects would enable EPIC to better serve the aerospace engineer and electric propulsion systems integrator. We review EPIC S overall capabilities and recent modifications, and discuss directions for future enhancements.

Dimension and bridging ligand effects on Mo-mediated catalytic transformation of dinitrogen to ammonia: Chain-like extended models of Nishibayashi’s catalyst

DOE PAGES

Sheng, Xiao -Lan; Batista, Enrique Ricardo; Duan, Yi -Xiang; ...

2016-11-01

Previous studies suggested that in Nishibayashi’s homogenous catalytic systems based on molybdenum (Mo) complexes, the bimetallic structure facilitated dinitrogen to ammonia conversion in comparison to the corresponding monometallic complexes, likely due to the through-bond interactions between the two Mo centers. However, more detailed model systems are necessary to support this bimetallic hypothesis, and to elucidate the multi-metallic effects on the catalytic mechanism. In this work, we computationally examined the effects of dimension as well as the types of bridging ligands on the catalytic activities of molybdenum-dinitrogen complexes by using a set of extended model systems based on Nishibayashi’s bimetallic structure.more » The polynuclear chains containing four ([Mo] 4) or more Mo centers were found to drastically enhance the catalytic performance by comparing with both the monometallic and bimetallic complexes. Carbide ([:C≡C:] 2–) was found to be a more effective bridging ligand than N 2 in terms of electronic charges dispersion between metal centers thereby facilitating reactions in the catalytic cycle. Furthermore, the mechanistic modelling suggests that in principle, more efficient catalytic system for N 2 to NH 3 transformation might be obtained by extending the polynuclear chain to a proper size in combination with an effective bridging ligand for charge dispersion.« less

Dimension and bridging ligand effects on Mo-mediated catalytic transformation of dinitrogen to ammonia: Chain-like extended models of Nishibayashi’s catalyst

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

Sheng, Xiao -Lan; Batista, Enrique Ricardo; Duan, Yi -Xiang

Previous studies suggested that in Nishibayashi’s homogenous catalytic systems based on molybdenum (Mo) complexes, the bimetallic structure facilitated dinitrogen to ammonia conversion in comparison to the corresponding monometallic complexes, likely due to the through-bond interactions between the two Mo centers. However, more detailed model systems are necessary to support this bimetallic hypothesis, and to elucidate the multi-metallic effects on the catalytic mechanism. In this work, we computationally examined the effects of dimension as well as the types of bridging ligands on the catalytic activities of molybdenum-dinitrogen complexes by using a set of extended model systems based on Nishibayashi’s bimetallic structure.more » The polynuclear chains containing four ([Mo] 4) or more Mo centers were found to drastically enhance the catalytic performance by comparing with both the monometallic and bimetallic complexes. Carbide ([:C≡C:] 2–) was found to be a more effective bridging ligand than N 2 in terms of electronic charges dispersion between metal centers thereby facilitating reactions in the catalytic cycle. Furthermore, the mechanistic modelling suggests that in principle, more efficient catalytic system for N 2 to NH 3 transformation might be obtained by extending the polynuclear chain to a proper size in combination with an effective bridging ligand for charge dispersion.« less

[Flipped Classroom: A New Teaching Strategy for Integrating Information Technology Into Nursing Education].

PubMed

Chiou, Shwu-Fen; Su, Hsiu-Chuan; Liu, Kuei-Fen; Hwang, Hei-Fen

2015-06-01

The traditional "teacher-centered" instruction model is still currently pervasive in nursing education. However, this model does not stimulate the critical thinking or foster the self-learning competence of students. In recent years, the rapid development of information technology and the changes in educational philosophy have encouraged the development of the "flipped classroom" concept. This concept completely subverts the traditional instruction model by allowing students to access and use related learning activities prior to class on their smartphones or tablet computers. Implementation of this concept has been demonstrated to facilitate greater classroom interaction between teachers and students, to stimulate student thinking, to guide problem solving, and to encourage cooperative learning and knowledge utilization in order to achieve the ideal of student-centered education. This student-centered model of instruction coincides with the philosophy of nursing education and may foster the professional competence of nursing students. The flipped classroom is already an international trend, and certain domestic education sectors have adopted and applied this concept as well. However, this concept has only just begun to make its mark on nursing education. This article describes the concept of the flipped classroom, the implementation myth, the current experience with implementing this concept in international healthcare education, and the challenging issues. We hope to provide a reference for future nursing education administrators who are responsible to implement flipped classroom teaching strategies in Taiwan.

Mobile Gaming and Student Interactions in a Science Center: The Future of Gaming in Science Education

ERIC Educational Resources Information Center

Atwood-Blaine, Dana; Huffman, Douglas

2017-01-01

This article explores the impact of an augmented reality iPad-based mobile game, called The Great STEM Caper, on students' interaction at a science center. An open-source, location-based game platform called ARIS (i.e. Augmented Reality and Interactive Storytelling) was used to create an iPad-based mobile game. The game used QR scan codes and a…

Identification of Coherent Structure Dynamics in Wall-Bounded Sprays using Proper Orthogonal Decomposition

DTIC Science & Technology

2010-08-31

Wall interaction of sprays emanating from Gas Centered Swirl Coaxial (GCSC) injectors were experimentally studied as a part of this ten-week project. A...American Society of Engineering Education (ASEE) Dated August 31st 2010 Abstract Wall interaction of sprays emanating from Gas Centered...Edwards Air Force Base (AFRL/EAFB) have documented atomization characteristics of a Gas -Centered Swirl Coaxial (GCSC) injector [1-2], in which the

University of Rhode Island Regional Earth Systems Center

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

Rothstein, Lewis; Cornillon, P.

The primary objective of this program was to establish the URI Regional Earth System Center (“Center”) that would enhance overall societal wellbeing (health, financial, environmental) by utilizing the best scientific information and technology to achieve optimal policy decisions with maximum stakeholder commitment for energy development, coastal environmental management, water resources protection and human health protection, while accelerating regional economic growth. The Center was to serve to integrate existing URI institutional strengths in energy, coastal environmental management, water resources, and human wellbeing. This integrated research, educational and public/private sector outreach Center was to focus on local, state and regional resources. Themore » centerpiece activity of the Center was in the development and implementation of integrated assessment models (IAMs) that both ‘downscaled’ global observations and interpolated/extrapolated regional observations for analyzing the complexity of interactions among humans and the natural climate system to further our understanding and, ultimately, to predict the future state of our regional earth system. The Center was to begin by first ‘downscaling’ existing global earth systems management tools for studying the causes of local, state and regional climate change and potential social and environmental consequences, with a focus on the regional resources identified above. The Center would ultimately need to address the full feedbacks inherent in the nonlinear earth systems by quantifying the “upscaled” impacts of those regional changes on the global earth system. Through an interacting suite of computer simulations that are informed by observations from the nation’s evolving climate observatories, the Center activities integrates climate science, technology, economics, and social policy into forecasts that will inform solutions to pressing issues in regional climate change science, ‘green economy’ investment and climate policy. These project objectives were designed as part of a 5-year program, which would have constituted the initial phase for the establishment of the Center. Almost immediately (i.e. before receiving even the first year of funding) we were informed that we would not be receiving any funding beyond the initial phase; one year. This seriously impacted our ability to deliver on our objectives and, with that, a re-scoping of the Center priorities was designed to fit the 1-year constraints on funding. It was decided that, given the Center’s emphasis on building IAMs, the best way to proceed was to first focus on one particularly important component of the IAM – a natural sciences model that would be useful for research and forecasting of the circualation/ecology/biogeochemistry of RI’s coastal waters. We have succeeded on that necessarily more limited objective, as we will describe below.« less

S2 like Star Orbits near the Galactic Center in Rn and Yukawa Gravity

NASA Astrophysics Data System (ADS)

Borka, Dusko; Jovanović, Predrag; Jovanović Vesna Borka; Zakharov, Alexander F.

2015-01-01

In this chapter we investigate the possibility to provide theoretical explanation for the observed deviations of S2 star orbit around the Galactic Center using gravitational potentials derived from extended gravity models, but in absence of dark matter. Extended Theories of Gravity are alternative theories of gravitational interaction developed from the exact starting points investigated first by Einstein and Hilbert and aimed from one side to extend the positive results of General Relativity and, on the other hand, to cure its shortcomings. One of the aims of these theories is to explain galactic and extragalactic dynamics without introduction of dark matter. They are based on straightforward generalizations of the Einstein theory where the gravitational action (the Hilbert-Einstein action) is assumed to be linear in the Ricci curvature scalar R. The f(R) gravity is a type of modified gravity which generalizes Einstein's General Relativity, i.e. the simplest case is just the General Relativity. It is actually a family of models, each one defined by a different function of the Ricci scalar. Here, we consider Rn (power-law fourth-order theories of gravity) and Yukawa-like modified gravities in the weak field limit and discuss the constrains on these theories. For that purpose we simulate the orbit of S2 star around the Galactic Center in Rn and Yukawa-like gravity potentials and compare it with New Technology Telescope/Very Large Telescope (NTT/VLT) as well as by Keck telescope observations. Our simulations result in strong constraints on the range of gravity interaction and showed that both Rn and Yukawa gravity could satisfactorily explain the observed orbits of S2 star. However, we concluded that parameters of Rn and Yukawa gravity theories must be very close to those corresponding to the Newtonian limit of the theory. Besides, in contrast to Newtonian gravity, these two modified theories induce orbital precession, even in the case of point-like central mass. The approach we are proposing seems to be sufficiently reliable to constrain the modified gravity models from stellar orbits around Galactic Center.

Mary S. Easton Center of Alzheimer’s Disease Research at UCLA: Advancing the Therapeutic Imperative

PubMed Central

Cummings, Jeffrey L.; Ringman, John; Metz, Karen

2010-01-01

The Mary S. Easton Center for Alzheimer’s Disease Research (UCLA-Easton Alzheimer’s Center) is committed to the “therapeutic imperative” and is devoted to finding new treatments for Alzheimer’s disease (AD) and to developing technologies (biomarkers) to advance that goal. The UCLA-Easton Alzheimer’s Center has a continuum of research and research-related activities including basic/foundational studies of peptide interactions; translational studies in transgenic animals and other animal models of AD; clinical research to define the phenotype of AD, characterize familial AD, develop biomarkers, and advance clinical trials; health services and outcomes research; and active education, dissemination, and recruitment activities. The UCLA-Easton Alzheimer’s Center is supported by the National Institutes on Aging, the State of California, and generous donors who share our commitment to developing new therapies for AD. The naming donor (Jim Easton) provided substantial funds to endow the center and to support projects in AD drug discovery and biomarker development. The Sidell-Kagan Foundation supports the Katherine and Benjamin Kagan Alzheimer’s Treatment Development Program, and the Deane F. Johnson Alzheimer’s Research Foundation supports the Deane F. Johnson Center for Neurotherapeutics at UCLA. The John Douglas French Alzheimer’s Research Foundation provides grants to junior investigators in critical periods of their academic development. The UCLA-Easton Alzheimer’s Center partners with community organizations including the Alzheimer’s Association California Southland Chapter and the Leeza Gibbons memory Foundation. Collaboration with pharmaceutical companies, biotechnology companies, and device companies is critical to developing new therapeutics for AD and these collaborations are embraced in the mission of the UCLA-Easton Alzheimer’s Center. The Center supports excellent senior investigators and serves as an incubator for new scientists, agents, models, technologies and concepts that will significantly influence the future of AD treatment and AD research. PMID:20110588

The impact of peer mentor communication with older adults on depressive symptoms and working alliance: A pilot study.

PubMed

Joo, Jin Hui; Hwang, Seungyoung; Gallo, Joseph J; Roter, Debra L

2018-04-01

The objective of this pilot study was to describe peer communication in meetings with depressed elders, associate their relationship with working alliance and depression and assess congruence of communication with training. Three peers with a history of depression, in recovery, received 20h of training in peer mentoring for depression as part of an 8-week pilot program for 23 depressed older adults. Each peer-client meeting was recorded; a sample of 69 recorded meetings were chosen across the program period and coded with the Roter Interaction Analysis System, a validated medical interaction analysis system. Generalized linear mixed models were used to examine peer talk during meetings in relation to working alliance and client depression. Peers used a variety of skills congruent with their training including client-centered talk, positive rapport building and emotional responsiveness that remained consistent or increased over time. Client-centered communication and positive rapport were associated with increased working alliance and decreased depressive symptoms (all p<0.001). Trained peer mentors can use communication behaviors useful to older adults with depression. Specifically, client-centered talk may be important to include in peer training. Peer mentors can be a valuable resource in providing depression counseling to older adults. Copyright © 2017 Elsevier B.V. All rights reserved.

The accumulation of femtosecond laser radiation energy in crystals of lithium fluoride

NASA Astrophysics Data System (ADS)

Dresvyanskiy, V. P.; Glazunov, D. S.; Alekseev, S. V.; Losev, V. F.; Chadraa, B.; Bukhtsooj, O.; Baasankhuu, N.; Zandan, B.; Martynovich, E. F.

2015-12-01

We present the results of studies of energy accumulation during the non-destructive interaction of extremely intense near infrared laser radiation with model wide band gap dielectric crystals of lithium fluoride, when the intensity of pulses is sufficient for effective highly nonlinear absorption of light and for the excitation of the electron subsystem of matter and the energy of pulses is still not sufficient for significant heating, evaporation, laser breakdown or other destruction to occur. We studied the emission of energy in the form of light sum of thermally stimulated luminescence accumulated under conditions of self-focusing and multiple filamentation of femtosecond laser radiation. It was established that it's the F2 and F3+ color centers and supplementary to them centers of interstitial type which accumulate energy under the action of a single femtosecond laser pulses. When irradiated by series of pulses the F3, F3- and F4 centers additionally appear. F2 centers are the main centers of emission in the process of thermally stimulated luminescence of accumulated energy. The interstitial fluoride ions (I-centers) are the kinetic particles. They split off from the X3- centers in the result of thermal decomposition of latter on the I-centers and molecules X20. I-centers recombine with F3+ centers and form F2 centers in excited state. The latter produce the characteristic emission spectrum emitted in the form of thermally stimulated luminescence.

Exploration Supply Chain Simulation

NASA Technical Reports Server (NTRS)

2008-01-01

The Exploration Supply Chain Simulation project was chartered by the NASA Exploration Systems Mission Directorate to develop a software tool, with proper data, to quantitatively analyze supply chains for future program planning. This tool is a discrete-event simulation that uses the basic supply chain concepts of planning, sourcing, making, delivering, and returning. This supply chain perspective is combined with other discrete or continuous simulation factors. Discrete resource events (such as launch or delivery reviews) are represented as organizational functional units. Continuous resources (such as civil service or contractor program functions) are defined as enabling functional units. Concepts of fixed and variable costs are included in the model to allow the discrete events to interact with cost calculations. The definition file is intrinsic to the model, but a blank start can be initiated at any time. The current definition file is an Orion Ares I crew launch vehicle. Parameters stretch from Kennedy Space Center across and into other program entities (Michaud Assembly Facility, Aliant Techsystems, Stennis Space Center, Johnson Space Center, etc.) though these will only gain detail as the file continues to evolve. The Orion Ares I file definition in the tool continues to evolve, and analysis from this tool is expected in 2008. This is the first application of such business-driven modeling to a NASA/government-- aerospace contractor endeavor.

A quantum annealing architecture with all-to-all connectivity from local interactions.

PubMed

Lechner, Wolfgang; Hauke, Philipp; Zoller, Peter

2015-10-01

Quantum annealers are physical devices that aim at solving NP-complete optimization problems by exploiting quantum mechanics. The basic principle of quantum annealing is to encode the optimization problem in Ising interactions between quantum bits (qubits). A fundamental challenge in building a fully programmable quantum annealer is the competing requirements of full controllable all-to-all connectivity and the quasi-locality of the interactions between physical qubits. We present a scalable architecture with full connectivity, which can be implemented with local interactions only. The input of the optimization problem is encoded in local fields acting on an extended set of physical qubits. The output is-in the spirit of topological quantum memories-redundantly encoded in the physical qubits, resulting in an intrinsic fault tolerance. Our model can be understood as a lattice gauge theory, where long-range interactions are mediated by gauge constraints. The architecture can be realized on various platforms with local controllability, including superconducting qubits, NV-centers, quantum dots, and atomic systems.

A quantum annealing architecture with all-to-all connectivity from local interactions

PubMed Central

Lechner, Wolfgang; Hauke, Philipp; Zoller, Peter

2015-01-01

Quantum annealers are physical devices that aim at solving NP-complete optimization problems by exploiting quantum mechanics. The basic principle of quantum annealing is to encode the optimization problem in Ising interactions between quantum bits (qubits). A fundamental challenge in building a fully programmable quantum annealer is the competing requirements of full controllable all-to-all connectivity and the quasi-locality of the interactions between physical qubits. We present a scalable architecture with full connectivity, which can be implemented with local interactions only. The input of the optimization problem is encoded in local fields acting on an extended set of physical qubits. The output is—in the spirit of topological quantum memories—redundantly encoded in the physical qubits, resulting in an intrinsic fault tolerance. Our model can be understood as a lattice gauge theory, where long-range interactions are mediated by gauge constraints. The architecture can be realized on various platforms with local controllability, including superconducting qubits, NV-centers, quantum dots, and atomic systems. PMID:26601316

Lateral distribution of muons in IceCube cosmic ray events

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker Tjus, J.; Becker, K.-H.; Bell, M.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brayeur, L.; Brown, A. M.; Bruijn, R.; Brunner, J.; Buitink, S.; Carson, M.; Casey, J.; Casier, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Cowen, D. F.; Cruz Silva, A. H.; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eagan, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Franke, R.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Heereman, D.; Heimann, P.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Jlelati, O.; Kappes, A.; Karg, T.; Karle, A.; Kiryluk, J.; Kislat, F.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lesiak-Bzdak, M.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Naumann, U.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pieloth, D.; Pirk, N.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rädel, L.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Salameh, T.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Scheel, M.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönherr, L.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Smith, M. W. E.; Soiron, M.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Usner, M.; van der Drift, D.; van Eijndhoven, N.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wasserman, R.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zilles, A.; Zoll, M.

2013-01-01

In cosmic ray air showers, the muon lateral separation from the center of the shower is a measure of the transverse momentum that the muon parent acquired in the cosmic ray interaction. IceCube has observed cosmic ray interactions that produce muons laterally separated by up to 400 m from the shower core, a factor of 6 larger distance than previous measurements. These muons originate in high pT (>2GeV/c) interactions from the incident cosmic ray, or high-energy secondary interactions. The separation distribution shows a transition to a power law at large values, indicating the presence of a hard pT component that can be described by perturbative quantum chromodynamics. However, the rates and the zenith angle distributions of these events are not well reproduced with the cosmic ray models tested here, even those that include charm interactions. This discrepancy may be explained by a larger fraction of kaons and charmed particles than is currently incorporated in the simulations.

Modeling Aromatic Liquids:  Toluene, Phenol, and Pyridine.

PubMed

Baker, Christopher M; Grant, Guy H

2007-03-01

Aromatic groups are now acknowledged to play an important role in many systems of interest. However, existing molecular mechanics methods provide a poor representation of these groups. In a previous paper, we have shown that the molecular mechanics treatment of benzene can be improved by the incorporation of an explicit representation of the aromatic π electrons. Here, we develop this concept further, developing charge-separation models for toluene, phenol, and pyridine. Monte Carlo simulations are used to parametrize the models, via the reproduction of experimental thermodynamic data, and our models are shown to outperform an existing atom-centered model. The models are then used to make predictions about the structures of the liquids at the molecular level and are tested further through their application to the modeling of gas-phase dimers and cation-π interactions.

Testing and Implementation of Advanced Reynolds Stress Models

NASA Technical Reports Server (NTRS)

Speziale, Charles G.

1997-01-01

A research program was proposed for the testing and implementation of advanced turbulence models for non-equilibrium turbulent flows of aerodynamic importance that are of interest to NASA. Turbulence models that are being developed in connection with the Office of Naval Research ARI in Non-equilibrium are provided for implementation and testing in aerodynamic flows at NASA Langley Research Center. Close interactions were established with researchers at Nasa Langley RC and refinements to the models were made based on the results of these tests. The models that have been considered include two-equation models with an anisotropic eddy viscosity as well as full second-order closures. Three types of non-equilibrium corrections to the models have been considered in connection with the ARI on Nonequilibrium Turbulence: conducted for ONR.

The role of feedback connections in shaping the responses of visual cortical neurons.

PubMed

Bullier, J; Hupé, J M; James, A C; Girard, P

2001-01-01

The results of a previous study [Hupé et al. (1998) Nature, 394: 784-787] led us to conclude that feedback connections are important for differentiating a figure from the background, particularly in the case of low salience stimuli. This conclusion was principally based on the observation in area V3 neurons that inactivating MT by cooling led to a severe weakening of the center response and of the center-surround interactions, and that these effects were particularly strong for low salience stimuli. In the present paper, we first show that the results extend to areas V1 and V2. In particular, the inhibitory center-surround interactions in areas V1, V2 and V3 disappear almost completely in the absence of feedback input from MT for low salience stimuli, whereas the effects are much more limited for stimuli of middle and high salience. We then compare the results obtained in studies of feedback connections from MT to those obtained in a study of the feedback action of area V2 onto V1 neurons [Hupé et al. (2001) J. Neurophysiol., 85: 146-163], in which the same effects were observed on the center mechanism (decrease in response), but no effects were seen on the center-surround interactions. We conclude that feedback connections act in a non-linear fashion to boost the gain of the center mechanism and that they combine with horizontal connections to generate the center-surround interactions.

A hierarchical distributed control model for coordinating intelligent systems

NASA Technical Reports Server (NTRS)

Adler, Richard M.

1991-01-01

A hierarchical distributed control (HDC) model for coordinating cooperative problem-solving among intelligent systems is described. The model was implemented using SOCIAL, an innovative object-oriented tool for integrating heterogeneous, distributed software systems. SOCIAL embeds applications in 'wrapper' objects called Agents, which supply predefined capabilities for distributed communication, control, data specification, and translation. The HDC model is realized in SOCIAL as a 'Manager'Agent that coordinates interactions among application Agents. The HDC Manager: indexes the capabilities of application Agents; routes request messages to suitable server Agents; and stores results in a commonly accessible 'Bulletin-Board'. This centralized control model is illustrated in a fault diagnosis application for launch operations support of the Space Shuttle fleet at NASA, Kennedy Space Center.

Intraseasonal Oscillations over South America: A Study with a Regional Climate Model

NASA Technical Reports Server (NTRS)

Chen, Baode; Chao, Winston

2003-01-01

The National Center for Atmospheric Research (NCAR) regional climate model version 2 (RegCM2) is used to investigate the observed characteristics of intraseasonal oscillations over South America. Our study is mainly concentrated on an intraseaonal mode, which is observed to account for a large portion of the intraseasonal variation, to have a standing feature and to be independent of the MJO. The NCEPDOE AMIP-II reanalysis is utilized to provide initial and lateral boundary conditions for the RegCM2 based upon the OOZ, 062, 122 and 182 data.Our results indicate that the intraseasonal oscillation still exists with time- averaged lateral boundary condition, which prevents the MJO and other outside disturbances from entering the model's domain, suggesting a locally forced oscillation responsible for ths intraseasonal mode independent of the MJO. Further experiments show that the annual and daily variabilities and a radiative-convective interaction are not essential to the locally forced intraseasonal oscillation. The intraseasonal oscillations over Amazon in our model essentially result from interactions among atmospheric continental- scale circulation, surface radiation, surface sensible and latent heat fluxes, and cumulus convection. The wavelet analyses of various surface energy fluxes and surface energy budget also verify that the primary cause of intraseasonal oscillation is the interaction of land surface processes with the atmosphere.

SPARC's Stratospheric Sulfur and its Role in Climate Activity (SSiRC)

NASA Technical Reports Server (NTRS)

Thomason, Larry

2015-01-01

The stratospheric aerosol layer is a key component in the climate system. It affects the radiative balance of the atmosphere directly through interactions with solar and terrestrial radiation, and indirectly through its effect on stratospheric ozone. Because the stratospheric aerosol layer is prescribed in many climate models and Chemistry-Climate Models (CCMs), model simulations of future atmospheric conditions and climate generally do not account for the interaction between the aerosol-sulfur cycle and changes in the climate system. The present understanding of how the stratospheric aerosol layer may be affected by future climate change and how the stratospheric aerosol layer may drive climate change is, therefore, very limited. The purposes of SSiRC (Stratospheric Sulfur and its Role in Climate) include: (i) providing a coordinating structure for the various individual activities already underway in different research centers; (ii) encouraging and supporting new instrumentation and measurements of sulfur containing compounds, such as COS, DMS, and non-volcanic SO2 in the UT/LS globally; and (iii) initiating new model/data inter-comparisons. SSiRC is developing collaborations with a number of other SPARC activities including CCMI and ACAM. This presentation will highlight the scientific goals of this project and on-going activities and propose potential interactions between SSiRC and ACAM.

Newly developed photon-cell interactive Monte Carlo (pciMC) simulation for non-invasive and continuous diagnosis of blood during extracorporeal circulation support

NASA Astrophysics Data System (ADS)

Sakota, Daisuke; Takatani, Setsuo

2011-07-01

We have sought for non-invasive diagnosis of blood during the extracorporeal circulation support. To achieve the goal, we have newly developed a photon-cell interactive Monte Carlo (pciMC) model for optical propagation through blood. The pciMC actually describes the interaction of photons with 3-dimentional biconcave RBCs. The scattering is described by micro-scopical RBC boundary condition based on geometric optics. By using pciMC, we modeled the RBCs inside the extracorporeal circuit will be oriented by the blood flow. The RBCs' orientation was defined as their long axis being directed to the center of the circulation tube. Simultaneously the RBCs were allowed to randomly rotate about the long axis direction. As a result, as flow rate increased, the orientation rate increased and converged to approximately 22% at 0.5 L/min flow rate and above. And finally, by using this model, the pciMC non-invasively and absolutely predicted Hct and hemoglobin with the accuracies of 0.84+/-0.82 [HCT%] and 0.42+/-0.28 [g/dL] respectively against measurements by a blood gas analyzer.

Experimental investigation of forebody and wing leading-edge vortex interactions at high angles of attack

NASA Technical Reports Server (NTRS)

Erickson, G. E.; Gilbert, W. P.

1983-01-01

An experimental investigation was conducted to assess the vortex flow-field interactions on an advanced, twin-jet fighter aircraft configuration at high angles of attack. Flow-field surveys were conducted on a small-scale model in the Northrop 0.41 - by 0.60-meter water tunnel and, where appropriate, the qualitative observations were correlated with low-speed wind tunnel data trends obtained on a large-scale model of the advanced fighter in the NASA Langley Research Center 30- by 60-foot (9.1- by 18.3-meter) facility. Emphasis was placed on understanding the interactions of the forebody and LEX-wing vortical flows, defining the effects on rolling moment variation with sideslip, and identifying modifications to control or regulate the vortex interactions at high angles of attack. The water tunnel flow visualization results and wind tunnel data trend analysis revealed the potential for strong interactions between the forebody and LEX vortices at high angles of attack. In particular, the forebody flow development near the nose could be controlled by means of carefully-positioned radome strakes. The resultant strake-induced flow-field changes were amplified downstream by the more powerful LEX vortical motions with subsequent large effects on wing flow separation characteristics.

Transformational leadership, transnational culture and political competence in globalizing health care services: a case study of Jordan's King Hussein Cancer Center.

PubMed

Moe, Jeffrey L; Pappas, Gregory; Murray, Andrew

2007-11-16

Following the demise of Jordan's King Hussein bin Talal to cancer in 1999, the country's Al-Amal Center was transformed from a poorly perceived and ineffectual cancer care institution into a Western-style comprehensive cancer center. Renamed King Hussein Cancer Center (KHCC), it achieved improved levels of quality, expanded cancer care services and achieved Joint Commission International accreditation under new leadership over a three-year period (2002-2005). An exploratory case research method was used to explain the rapid change to international standards. Sources including personal interviews, document review and on-site observations were combined to conduct a robust examination of KHCC's rapid changes. The changes which occurred at the KHCC during its formation and leading up to its Joint Commission International (JCI) accreditation can be understood within the conceptual frame of the transformational leadership model. Interviewees and other sources for the case study suggest the use of inspirational motivation, idealized influence, individualized consideration and intellectual stimulation, four factors in the transformational leadership model, had significant impact upon the attitudes and motivation of staff within KHCC. Changes in the institution were achieved through increased motivation and positive attitudes toward the use of JCI continuous improvement processes as well as increased professional training. The case study suggests the role of culture and political sensitivity needs re-definition and expansion within the transformational leadership model to adequately explain leadership in the context of globalizing health care services, specifically when governments are involved in the change initiative. The KHCC case underscores the utility of the transformational leadership model in an international health care context. To understand leadership in globalizing health care services, KHCC suggests culture is broader than organizational or societal culture to include an informal global network of medical professionals and Western technologies which facilitate global interaction. Additionally, political competencies among leaders may be particularly relevant in globalizing health care services where the goal is achieving international standards of care. Western communication technologies facilitate cross-border interaction, but social and political capital possessed by the leaders may be necessary for transactions across national borders to occur thus gaining access to specialized information and global thought leaders in a medical sub-specialty such as oncology.

Transformational leadership, transnational culture and political competence in globalizing health care services: a case study of Jordan's King Hussein Cancer Center

PubMed Central

Moe, Jeffrey L; Pappas, Gregory; Murray, Andrew

2007-01-01

Background Following the demise of Jordan's King Hussein bin Talal to cancer in 1999, the country's Al-Amal Center was transformed from a poorly perceived and ineffectual cancer care institution into a Western-style comprehensive cancer center. Renamed King Hussein Cancer Center (KHCC), it achieved improved levels of quality, expanded cancer care services and achieved Joint Commission International accreditation under new leadership over a three-year period (2002–2005). Methods An exploratory case research method was used to explain the rapid change to international standards. Sources including personal interviews, document review and on-site observations were combined to conduct a robust examination of KHCC's rapid changes. Results The changes which occurred at the KHCC during its formation and leading up to its Joint Commission International (JCI) accreditation can be understood within the conceptual frame of the transformational leadership model. Interviewees and other sources for the case study suggest the use of inspirational motivation, idealized influence, individualized consideration and intellectual stimulation, four factors in the transformational leadership model, had significant impact upon the attitudes and motivation of staff within KHCC. Changes in the institution were achieved through increased motivation and positive attitudes toward the use of JCI continuous improvement processes as well as increased professional training. The case study suggests the role of culture and political sensitivity needs re-definition and expansion within the transformational leadership model to adequately explain leadership in the context of globalizing health care services, specifically when governments are involved in the change initiative. Conclusion The KHCC case underscores the utility of the transformational leadership model in an international health care context. To understand leadership in globalizing health care services, KHCC suggests culture is broader than organizational or societal culture to include an informal global network of medical professionals and Western technologies which facilitate global interaction. Additionally, political competencies among leaders may be particularly relevant in globalizing health care services where the goal is achieving international standards of care. Western communication technologies facilitate cross-border interaction, but social and political capital possessed by the leaders may be necessary for transactions across national borders to occur thus gaining access to specialized information and global thought leaders in a medical sub-specialty such as oncology. PMID:18021412

Smagglce: Surface Modeling and Grid Generation for Iced Airfoils: Phase 1 Results

NASA Technical Reports Server (NTRS)

Vickerman, Mary B.; Choo, Yung K.; Braun, Donald C.; Baez, Marivell; Gnepp, Steven

1999-01-01

SmaggIce (Surface Modeling and Grid Generation for Iced Airfoils) is a software toolkit used in the process of aerodynamic performance prediction of iced airfoils with grid-based Computational Fluid Dynamics (CFD). It includes tools for data probing, boundary smoothing, domain decomposition, and structured grid generation and refinement. SmaggIce provides the underlying computations to perform these functions, a GUI (Graphical User Interface) to control and interact with those functions, and graphical displays of results, it is being developed at NASA Glenn Research Center. This paper discusses the overall design of SmaggIce as well as what has been implemented in Phase 1. Phase 1 results provide two types of software tools: interactive ice shape probing and interactive ice shape control. The ice shape probing tools will provide aircraft icing engineers and scientists with an interactive means to measure the physical characteristics of ice shapes. On the other hand, the ice shape control features of SmaggIce will allow engineers to examine input geometry data, correct or modify any deficiencies in the geometry, and perform controlled systematic smoothing to a level that will make the CFD process manageable.

The Electric Propulsion Interactions Code (EPIC): A Member of the NASA Space Environment and Effects Program (SEE) Toolset

NASA Technical Reports Server (NTRS)

Mikellides, Ioannis G.; Mandell, Myron J.; Kuharski, Robert A.; Davis, D. A.; Gardner, Barbara M.; Minor, Jody

2003-01-01

Science Applications International Corporation is currently developing the Electric Propulsion Interactions Code, EPIC, as part of a project sponsored by the Space Environments and Effects Program at NASA Marshall Space Flight Center. Now in its second year of development, EPIC is an interactive computer toolset that allows the construction of a 3-D spacecraft model, and the assessment of a variety of interactions between its subsystems and the plume from an electric thruster. This paper reports on the progress of EPZC including the recently added ability to exchange results the NASA Charging Analyzer Program, Nascap-2k. The capability greatly enhances EPIC's range of applicability. Expansion of the toolset's various physics models proceeds in parallel with the overall development of the software. Also presented are recent upgrades of the elastic scattering algorithm in the electric propulsion Plume Tool. These upgrades are motivated by the need to assess the effects of elastically scattered ions on the SIC for ion beam energies that exceed loo0 eV. Such energy levels are expected in future high-power (>10 kW) ion propulsion systems empowered by nuclear sources.

A Forecast Skill Comparison between CliPAS One-Tier and Two-Tier Hindcast Experiments

NASA Astrophysics Data System (ADS)

Lee, J.; Wang, B.; Kang, I.

2006-05-01

A 24-year (1981-2004) MME hindcast experimental dataset is produced under the "Climate Prediction and Its Application to Society" (CliPAS) project sponsored by Korean Meteorological Administration (KMA). This dataset consists of 5 one-tier model systems from National Aeronautics and Space Administration (NASA), National Center for Environmental Prediction (NCEP), Frontier Research Center for Global Change (FRCGC), Seoul National University (SNU), and University of Hawaii (UH) and 5 two-tier model systems from Florida State University (FSU), Geophysical Fluid Dynamic Lab (GFDL), SNU, and UH. Multi-model Ensemble (MME) Forecast skills of seasonal precipitation and atmospheric circulation are compared between CliPAS one-tier and two-tier hindcast experiments for seasonal mean precipitation and atmospheric circulation. For winter prediction, two-tier MME has a comparable skill to one-tier MME. However, it is demonstrated that in the Asian-Australian monsoon (A-AM) heavy precipitation regions, one-tier systems are superior to two-tier systems in summer season. The reason is that inclusion of the local warm pool- monsoon interaction in the one-tier system improves the ENSO teleconnection with monsoon regions. Both one-tier and two-tier MME fail to predict Indian monsoon circulation, while they have a significantly good skill for the broad scale monsoon circulation defined by Webster and Yang index. One-tier system has a much better skill to predict the monsoon circulation over the western North pacific where air-sea interaction plays an important role than two-tier system.

Delineation of spatial-temporal patterns of groundwater/surface-water interaction along a river reach (Aa River, Belgium) with transient thermal modeling

NASA Astrophysics Data System (ADS)

Anibas, Christian; Tolche, Abebe Debele; Ghysels, Gert; Nossent, Jiri; Schneidewind, Uwe; Huysmans, Marijke; Batelaan, Okke

2018-05-01

Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached -90 mm d-1, while in spring and early summer fluxes were -42 mm d-1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.

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

McLaughlin, E.; Gupta, S.

This project mainly involves a molecular dynamics and Monte Carlo study of the effect of molecular shape on thermophysical properties of bulk fluids with an emphasis on the aromatic hydrocarbon liquids. In this regard we have studied the modeling, simulation methodologies, and predictive and correlating methods for thermodynamic properties of fluids of nonspherical molecules. In connection with modeling we have studied the use of anisotropic site-site potentials, through a modification of the Gay-Berne Gaussian overlap potential, to successfully model the aromatic rings after adding the necessary electrostatic moments. We have also shown these interaction sites should be located at themore » geometric centers of the chemical groups. In connection with predictive methods, we have shown two perturbation type theories to work well for fluids modeled using one-center anisotropic potentials and the possibility exists for extending these to anisotropic site-site models. In connection with correlation methods, we have studied, through simulations, the effect of molecular shape on the attraction term in the generalized van der Waals equation of state for fluids of nonspherical molecules and proposed a possible form which is to be studied further. We have successfully studied the vector and parallel processing aspects of molecular simulations for fluids of nonspherical molecules.« less

WIMPs at the galactic center

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

Agrawal, Prateek; Batell, Brian; Fox, Patrick J.

2015-05-07

Simple models of weakly interacting massive particles (WIMPs) predict dark matter annihilations into pairs of electroweak gauge bosons, Higgses or tops, which through their subsequent cascade decays produce a spectrum of gamma rays. Intriguingly, an excess in gamma rays coming from near the Galactic center has been consistently observed in Fermi data. A recent analysis by the Fermi collaboration confirms these earlier results. Taking into account the systematic uncertainties in the modelling of the gamma ray backgrounds, we show for the first time that this excess can be well fit by these final states. In particular, for annihilations to (WW,more » ZZ, hh, tt{sup -bar}), dark matter with mass between threshold and approximately (165, 190, 280, 310) GeV gives an acceptable fit. The fit range for bb{sup -bar} is also enlarged to 35 GeV≲m{sub χ}≲165 GeV. These are to be compared to previous fits that concluded only much lighter dark matter annihilating into b, τ, and light quark final states could describe the excess. We demonstrate that simple, well-motivated models of WIMP dark matter including a thermal-relic neutralino of the MSSM, Higgs portal models, as well as other simplified models can explain the excess.« less

WIMPs at the galactic center

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

Agrawal, Prateek; Batell, Brian; Fox, Patrick J.

Simple models of weakly interacting massive particles (WIMPs) predict dark matter annihilations into pairs of electroweak gauge bosons, Higgses or tops, which through their subsequent cascade decays produce a spectrum of gamma rays. Intriguingly, an excess in gamma rays coming from near the Galactic center has been consistently observed in Fermi data. A recent analysis by the Fermi collaboration confirms these earlier results. Taking into account the systematic uncertainties in the modelling of the gamma ray backgrounds, we show for the first time that this excess can be well fit by these final states. In particular, for annihilations to (WW,more » ZZ, hh, tt¯), dark matter with mass between threshold and approximately (165, 190, 280, 310) GeV gives an acceptable fit. The fit range for bb¯ is also enlarged to 35 GeV ≲ m χ ≲ 165 GeV. These are to be compared to previous fits that concluded only much lighter dark matter annihilating into b, τ, and light quark final states could describe the excess. We demonstrate that simple, well-motivated models of WIMP dark matter including a thermal-relic neutralino of the MSSM, Higgs portal models, as well as other simplified models can explain the excess.« less

WIMPs at the galactic center

DOE PAGES

Agrawal, Prateek; Batell, Brian; Fox, Patrick J.; ...

2015-05-07

Simple models of weakly interacting massive particles (WIMPs) predict dark matter annihilations into pairs of electroweak gauge bosons, Higgses or tops, which through their subsequent cascade decays produce a spectrum of gamma rays. Intriguingly, an excess in gamma rays coming from near the Galactic center has been consistently observed in Fermi data. A recent analysis by the Fermi collaboration confirms these earlier results. Taking into account the systematic uncertainties in the modelling of the gamma ray backgrounds, we show for the first time that this excess can be well fit by these final states. In particular, for annihilations to (WW,more » ZZ, hh, tt¯), dark matter with mass between threshold and approximately (165, 190, 280, 310) GeV gives an acceptable fit. The fit range for bb¯ is also enlarged to 35 GeV ≲ m χ ≲ 165 GeV. These are to be compared to previous fits that concluded only much lighter dark matter annihilating into b, τ, and light quark final states could describe the excess. We demonstrate that simple, well-motivated models of WIMP dark matter including a thermal-relic neutralino of the MSSM, Higgs portal models, as well as other simplified models can explain the excess.« less

Interactivity Centered Usability Evaluation (ICUE) for Course Management Systems

ERIC Educational Resources Information Center

Yoon, Sangil

2010-01-01

ICUE (Interactivity Centered Usability Evaluation) is an enhanced usability testing protocol created by the researcher. ICUE augments the facilitator's role for usability testing, and offers strategies in developing and presenting usability tasks during a testing session. ICUE was designed to address weaknesses found in the usability evaluation of…

Family Sense-Making Practices in Science Center Conversations

ERIC Educational Resources Information Center

Zimmerman, Heather Toomey; Reeve, Suzanne; Bell, Philip

2010-01-01

In this paper, we examine the interactional ways that families make meaning from biological exhibits during a visit to an interactive science center. To understand the museum visits from the perspectives of the families, we use ethnographic and discourse analytic methods, including pre- and postvisit interviews, videotaped observations of the…

Physical Interactions Involving Preschoolers and Kindergartners in a Childcare Center

ERIC Educational Resources Information Center

Fleck, Bethany; Chavajay, Pablo

2009-01-01

This naturalistic observational study described the similarities and differences in physical interactions involving preschoolers and kindergartners within the context of a US childcare facility. It examined patterns of touch involving the children across center and circle activities within the course of their day. Results indicated that…

Multilingual Institutional Discourses of Negotiation and Intertextuality in Writing Center Interactions in Macao

ERIC Educational Resources Information Center

Lee, Alice Shu-Ju

2017-01-01

This dissertation explores the identity enactments (Bucholtz & Hall, 2005) of 14 multilingual university writing center tutors and multilingual student writers who use English and Putonghua to negotiate their interactions. The study is situated within sociocultural theory (Vygotsky, 1978) and uses ethnographic methods such as observation,…

76 FR 17659 - National Center for Complementary and Alternative Medicine Announcement of Stakeholder Roundtable

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-30

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Center for... meaningful interaction, space is limited. To attend, please RSVP by Friday, April 1, 2011, by contacting.... To allow for meaningful interaction, space is limited. To attend, please RSVP by Friday, April 1...

Particle Engulfment and Pushing By Solidifying Interfaces

NASA Technical Reports Server (NTRS)

2003-01-01

The study of particle behavior at solid/liquid interfaces (SLI s) is at the center of the Particle Engulfment and Pushing (PEP) research program. Interactions of particles with SLI s have been of interest since the 1960 s, starting with geological observations, i.e., frost heaving. Ever since, this field of research has become significant to such diverse areas as metal matrix composite materials, fabrication of superconductors, and inclusion control in steels. The PEP research effort is geared towards understanding the fundamental physics of the interaction between particles and a planar SLI. Experimental work including 1-g and mu-g experiments accompany the development of analytical and numerical models. The experimental work comprised of substantial groundwork with aluminum (Al) and zinc (Zn) matrices containing spherical zirconia particles, mu-g experiments with metallic Al matrices and the use of transparent organic metal-analogue materials. The modeling efforts have grown from the initial steady-state analytical model to dynamic models, accounting for the initial acceleration of a particle at rest by an advancing SLI. To gain a more comprehensive understanding, numerical models were developed to account for the influence of the thermal and solutal field. Current efforts are geared towards coupling the diffusive 2-D front tracking model with a fluid flow model to account for differences in the physics of interaction between 1-g and -g environments. A significant amount of this theoretical investigation has been and is being performed by co-investigators at NASA MSFC.

Privacy preserving interactive record linkage (PPIRL)

PubMed Central

Kum, Hye-Chung; Krishnamurthy, Ashok; Machanavajjhala, Ashwin; Reiter, Michael K; Ahalt, Stanley

2014-01-01

Objective Record linkage to integrate uncoordinated databases is critical in biomedical research using Big Data. Balancing privacy protection against the need for high quality record linkage requires a human–machine hybrid system to safely manage uncertainty in the ever changing streams of chaotic Big Data. Methods In the computer science literature, private record linkage is the most published area. It investigates how to apply a known linkage function safely when linking two tables. However, in practice, the linkage function is rarely known. Thus, there are many data linkage centers whose main role is to be the trusted third party to determine the linkage function manually and link data for research via a master population list for a designated region. Recently, a more flexible computerized third-party linkage platform, Secure Decoupled Linkage (SDLink), has been proposed based on: (1) decoupling data via encryption, (2) obfuscation via chaffing (adding fake data) and universe manipulation; and (3) minimum information disclosure via recoding. Results We synthesize this literature to formalize a new framework for privacy preserving interactive record linkage (PPIRL) with tractable privacy and utility properties and then analyze the literature using this framework. Conclusions Human-based third-party linkage centers for privacy preserving record linkage are the accepted norm internationally. We find that a computer-based third-party platform that can precisely control the information disclosed at the micro level and allow frequent human interaction during the linkage process, is an effective human–machine hybrid system that significantly improves on the linkage center model both in terms of privacy and utility. PMID:24201028

The stability of a crystal with diamond structure for patchy particles with tetrahedral symmetry.

PubMed

Noya, Eva G; Vega, Carlos; Doye, Jonathan P K; Louis, Ard A

2010-06-21

The phase diagram of model anisotropic particles with four attractive patches in a tetrahedral arrangement has been computed at two different values of the range of the potential, with the aim of investigating the conditions under which a diamond crystal can be formed. We find that the diamond phase is never stable for our longer-ranged potential. At low temperatures and pressures, the fluid freezes into a body-centered-cubic solid that can be viewed as two interpenetrating diamond lattices with a weak interaction between the two sublattices. Upon compression, an orientationally ordered face-centered-cubic crystal becomes more stable than the body-centered-cubic crystal, and at higher temperatures, a plastic face-centered-cubic phase is stabilized by the increased entropy due to orientational disorder. A similar phase diagram is found for the shorter-ranged potential, but at low temperatures and pressures, we also find a region over which the diamond phase is thermodynamically favored over the body-centered-cubic phase. The higher vibrational entropy of the diamond structure with respect to the body-centered-cubic solid explains why it is stable even though the enthalpy of the latter phase is lower. Some preliminary studies on the growth of the diamond structure starting from a crystal seed were performed. Even though the diamond phase is never thermodynamically stable for the longer-ranged model, direct coexistence simulations of the interface between the fluid and the body-centered-cubic crystal and between the fluid and the diamond crystal show that at sufficiently low pressures, it is quite probable that in both cases the solid grows into a diamond crystal, albeit involving some defects. These results highlight the importance of kinetic effects in the formation of diamond crystals in systems of patchy particles.

Solving the Shortage of STEM Personnel in Navy Laboratories: Strategic Plan for Navy Investments in STEM Education Targeted at the Navy After Next

DTIC Science & Technology

2009-06-01

mote interactions among K12 school systems; 2- and 4-year colleges and universities; informal science education organizations; . . . to promote... Science Center Proposal As ‘ informal ’ education centers i.e., Science and Technology Centers provide learn- ing outside the classroom that enhances...and complements ‘formal’ (classroom-based) learning. Informal science education uses visual, auditory, physical interactions, and ac- tivities to

'It just has to click': Internists' views of: what constitutes productive interactions with chronically ill patients.

PubMed

Kromme, N M H; Ahaus, C T B; Gans, R O B; van de Wiel, H B M

2016-05-27

According to the Chronic Care Model, productive interactions are crucial to patient outcomes. Despite productive interactions being at the heart of the Model, however, it is unclear what constitutes such an interaction. The aim of this study was to gain a better understanding of physician views of productive interactions with the chronically ill. We conducted a qualitative study and interviewed 20 internists working in an academic hospital. The data were analyzed using a constructivist approach of grounded theory. To categorize the data, a coding process within which a code list was developed and tested with two other coders was conducted. The participants engaged in goal-directed reasoning when reflecting on productive interactions. This resulted in the identification of four goal orientations: (a) health outcome; (b) satisfaction; (c) medical process; and (d) collaboration. Collaboration appeared to be conditional for reaching medical process goals and ultimately health outcome and satisfaction goals. Achieving rapport with the patient ('clicking,' in the term of the participants) was found to be a key condition that catalyzed collaboration goals. Clicking appeared to be seen as a somewhat unpredictable phenomenon that might or might not emerge, which one had to accept and work with. Goal orientations were found to be related to the specific medical context (i.e., a participant's subspecialty and the nature of a patient's complaint). The participants viewed a productive interaction as essentially goal-directed, catalyzed by the two parties clicking, and dependent on the nature of a patient's complaint. Using the findings, we developed a conceptual process model with the four goal orientations as wheels and with clicking in the center as a flywheel. Because clicking was viewed as important, but somewhat unpredictable, teaching physicians how to click, while taking account of the medical context, may warrant greater attention.

Habitat preferences of two sparrow species are modified by abundances of other birds in an urban environment

PubMed Central

Skórka, Piotr; Sierpowska, Katarzyna; Haidt, Andżelika; Myczko, Łukasz; Ekner-Grzyb, Anna; Rosin, Zuzanna M.; Kwieciński, Zbigniew; Suchodolska, Joanna; Takacs, Viktoria; Jankowiak, Łukasz; Wasielewski, Oskar; Graclik, Agnieszka; Krawczyk, Agata J.; Kasprzak, Adam; Szwajkowski, Przemysław; Wylegała, Przemysław; Malecha, Anna W.; Mizera, Tadeusz; Tryjanowski, Piotr

2016-01-01

Abstract Every species has certain habitat requirements, which may be altered by interactions with other co-occurring species. These interactions are mostly ignored in predictive models trying to identify key habitat variables correlated with species population abundance/occurrence. We investigated how the structure of the urban landscape, food resources, potential competitors, predators, and interaction between these factors influence the abundance of house sparrow Passer domesticus and the tree sparrow P. montanus in sixty 25 ha plots distributed randomly across residential areas of the city of Poznań (Poland). The abundance of the house sparrow was positively correlated with the abundance of pigeons but negatively correlated with human-related food resources. There were significant interaction terms between abundances of other urban species and habitat variables in statistical models. For example, the abundance of house sparrow was negatively correlated with the abundance of corvids and tree sparrows but only when food resources were low. The abundance of tree sparrows positively correlated with density of streets and the distance from the city center. The abundance of this species positively correlated with the abundance of corvids when food resources were low but negatively correlated at low covers of green area. Our study indicates that associations between food resources, habitat covers, and the relative abundance of two sparrow species are altered by the abundance of other urban species. Competition, niche separation and social facilitation may be responsible for these interactive effects. Thus, biotic interactions should be included not only as an additive effect but also as an interaction term between abundance and habitat variables in statistical models predicting species abundance and occurrence. PMID:29491924

Learning by Peers: An Alternative Learning Model for Digital Inclusion of Elderly People

NASA Astrophysics Data System (ADS)

de Sales, Márcia Barros; Silveira, Ricardo Azambuja; de Sales, André Barros; de Cássia Guarezi, Rita

This paper presents a model of digital inclusion for the elderly people, using learning by peers methodology. The model’s goal was valuing and promoting the potential capabilities of the elderly people by promoting some of them to instruct other elderly people to deal with computers and to use several software tools and internet services. The project involved 66 volunteering elderly people. However, 19 of them acted effectively as multipliers and the others as students. The process was observed through the empirical technique of interaction workshops. This technique was chosen for demanding direct participation of the people involved in real interaction. We worked with peer learning to facilitate the communication between elderly-learners and elderly-multipliers, due to the similarity in language, rhythm and life history, and because they felt more secure to develop the activities with people in their age group. This multiplying model can be used in centers, organizations and other entities that work with elderly people for their digital inclusion.

Probing α -RuCl3 Beyond Magnetic Order: Effects of Temperature and Magnetic Field

NASA Astrophysics Data System (ADS)

Winter, Stephen M.; Riedl, Kira; Kaib, David; Coldea, Radu; Valentí, Roser

2018-02-01

Recent studies have brought α -RuCl3 to the forefront of experimental searches for materials realizing Kitaev spin-liquid physics. This material exhibits strongly anisotropic exchange interactions afforded by the spin-orbit coupling of the 4 d Ru centers. We investigate the dynamical response at finite temperature and magnetic field for a realistic model of the magnetic interactions in α -RuCl3 . These regimes are thought to host unconventional paramagnetic states that emerge from the suppression of magnetic order. Using exact diagonalization calculations of the quantum model complemented by semiclassical analysis, we find a very rich evolution of the spin dynamics as the applied field suppresses the zigzag order and stabilizes a quantum paramagnetic state that is adiabatically connected to the fully polarized state at high fields. At finite temperature, we observe large redistributions of spectral weight that can be attributed to the anisotropic frustration of the model. These results are compared to recent experiments and provide a road map for further studies of these regimes.

First PIC simulations modeling the interaction of ultra-intense lasers with sub-micron, liquid crystal targets

NASA Astrophysics Data System (ADS)

McMahon, Matthew; Poole, Patrick; Willis, Christopher; Andereck, David; Schumacher, Douglass

2014-10-01

We recently introduced liquid crystal films as on-demand, variable thickness (50-5000 nanometers), low cost targets for intense laser experiments. Here we present the first particle-in-cell (PIC) simulations of short pulse laser excitation of liquid crystal targets treating Scarlet (OSU) class lasers using the PIC code LSP. In order to accurately model the target evolution, a low starting temperature and field ionization model are employed. This is essential as large starting temperatures, often used to achieve large Debye lengths, lead to expansion of the target causing significant reduction of the target density before the laser pulse can interact. We also present an investigation of the modification of laser pulses by very thin targets. This work was supported by the DARPA PULSE program through a grant from ARMDEC, by the US Department of Energy under Contract No. DE-NA0001976, and allocations of computing time from the Ohio Supercomputing Center.

Control volume analyses of glottal flow using a fully-coupled numerical fluid-structure interaction model

NASA Astrophysics Data System (ADS)

Yang, Jubiao; Krane, Michael; Zhang, Lucy

2013-11-01

Vocal fold vibrations and the glottal jet are successfully simulated using the modified Immersed Finite Element method (mIFEM), a fully coupled dynamics approach to model fluid-structure interactions. A self-sustained and steady vocal fold vibration is captured given a constant pressure input at the glottal entrance. The flow rates at different axial locations in the glottis are calculated, showing small variations among them due to the vocal fold motion and deformation. To further facilitate the understanding of the phonation process, two control volume analyses, specifically with Bernoulli's equation and Newton's 2nd law, are carried out for the glottal flow based on the simulation results. A generalized Bernoulli's equation is derived to interpret the correlations between the velocity and pressure temporally and spatially along the center line which is a streamline using a half-space model with symmetry boundary condition. A specialized Newton's 2nd law equation is developed and divided into terms to help understand the driving mechanism of the glottal flow.

Hidden Sector Dark Matter Models for the Galactic Center Gamma-Ray Excess

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

Berlin, Asher; Gratia, Pierre; Hooper, Dan

2014-07-24

The gamma-ray excess observed from the Galactic Center can be interpreted as dark matter particles annihilating into Standard Model fermions with a cross section near that expected for a thermal relic. Although many particle physics models have been shown to be able to account for this signal, the fact that this particle has not yet been observed in direct detection experiments somewhat restricts the nature of its interactions. One way to suppress the dark matter's elastic scattering cross section with nuclei is to consider models in which the dark matter is part of a hidden sector. In such models, themore » dark matter can annihilate into other hidden sector particles, which then decay into Standard Model fermions through a small degree of mixing with the photon, Z, or Higgs bosons. After discussing the gamma-ray signal from hidden sector dark matter in general terms, we consider two concrete realizations: a hidden photon model in which the dark matter annihilates into a pair of vector gauge bosons that decay through kinetic mixing with the photon, and a scenario within the generalized NMSSM in which the dark matter is a singlino-like neutralino that annihilates into a pair of singlet Higgs bosons, which decay through their mixing with the Higgs bosons of the MSSM.« less

Modeling Tool Advances Rotorcraft Design

NASA Technical Reports Server (NTRS)

2007-01-01

Continuum Dynamics Inc. (CDI), founded in 1979, specializes in advanced engineering services, including fluid dynamic modeling and analysis for aeronautics research. The company has completed a number of SBIR research projects with NASA, including early rotorcraft work done through Langley Research Center, but more recently, out of Ames Research Center. NASA Small Business Innovation Research (SBIR) grants on helicopter wake modeling resulted in the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), a tool for studying helicopter and tiltrotor unsteady free wake modeling, including distributed and integrated loads, and performance prediction. Application of the software code in a blade redesign program for Carson Helicopters, of Perkasie, Pennsylvania, increased the payload and cruise speeds of its S-61 helicopter. Follow-on development resulted in a $24 million revenue increase for Sikorsky Aircraft Corporation, of Stratford, Connecticut, as part of the company's rotor design efforts. Now under continuous development for more than 25 years, CHARM models the complete aerodynamics and dynamics of rotorcraft in general flight conditions. CHARM has been used to model a broad spectrum of rotorcraft attributes, including performance, blade loading, blade-vortex interaction noise, air flow fields, and hub loads. The highly accurate software is currently in use by all major rotorcraft manufacturers, NASA, the U.S. Army, and the U.S. Navy.

Teaching infant car seat installation via interactive visual presence: An experimental trial.

PubMed

Schwebel, David C; Johnston, Anna; Rouse, Jenni

2017-02-17

A large portion of child restraint systems (car seats) are installed incorrectly, especially when first-time parents install infant car seats. Expert instruction greatly improves the accuracy of car seat installation but is labor intensive and difficult to obtain for many parents. This study was designed to evaluate the efficacy of 3 ways of communicating instructions for proper car seat installation: phone conversation; HelpLightning, a mobile application (app) that offers virtual interactive presence permitting both verbal and interactive (telestration) visual communication; and the manufacturer's user manual. A sample of 39 young adults of child-bearing age who had no previous experience installing car seats were recruited and randomly assigned to install an infant car seat using guidance from one of those 3 communication sources. Both the phone and interactive app were more effective means to facilitate accurate car seat installation compared to the user manual. There was a trend for the app to offer superior communication compared to the phone, but that difference was not significant in most assessments. The phone and app groups also installed the car seat more efficiently and perceived the communication to be more effective and their installation to be more accurate than those in the user manual group. Interactive communication may help parents install car seats more accurately than using the manufacturer's manual alone. This was an initial study with a modestly sized sample; if results are replicated in future research, there may be reason to consider centralized "call centers" that provide verbal and/or interactive visual instruction from remote locations to parents installing car seats, paralleling the model of centralized Poison Control centers in the United States.

A Shotline Method for Modeling Projectile Geometry

DTIC Science & Technology

1986-06-01

by block number) GIFT Target Description Vulnerability Analysis COMGEOM Shotlining Warhead Lethality MISFIR 20. ABSTRACT fConfteue an r»r»r«» eUm It rt...target interaction is centered upon the program MISFIR, written in CDC Fortran 5. MISFIR is built on the formalisms of the GIFT (Geometric...a ray-tracing subroutine added to GIFT (viz. SHOTCYL); MISFIR itself, together with its subprograms; and an application program, called FUZES, which

Experiments with Interaction between the National Water Model and the Reservoir System Simulation Model: A Case Study of Russian River Basin

NASA Astrophysics Data System (ADS)

Kim, J.; Johnson, L.; Cifelli, R.; Chandra, C. V.; Gochis, D.; McCreight, J. L.; Yates, D. N.; Read, L.; Flowers, T.; Cosgrove, B.

2017-12-01

NOAA National Water Center (NWC) in partnership with the National Centers for Environmental Prediction (NCEP), the National Center for Atmospheric Research (NCAR) and other academic partners have produced operational hydrologic predictions for the nation using a new National Water Model (NWM) that is based on the community WRF-Hydro modeling system since the summer of 2016 (Gochis et al., 2015). The NWM produces a variety of hydrologic analysis and prediction products, including gridded fields of soil moisture, snowpack, shallow groundwater levels, inundated area depths, evapotranspiration as well as estimates of river flow and velocity for approximately 2.7 million river reaches. Also included in the NWM are representations for more than 1,200 reservoirs which are linked into the national channel network defined by the USGS NHDPlusv2.0 hydrography dataset. Despite the unprecedented spatial and temporal coverage of the NWM, many known deficiencies exist, including the representation of lakes and reservoirs. This study addresses the implementation of a reservoir assimilation scheme through coupling of a reservoir simulation model to represent the influence of managed flows. We examine the use of the reservoir operations to dynamically update lake/reservoir storage volume states, characterize flow characteristics of river reaches flowing into and out of lakes and reservoirs, and incorporate enhanced reservoir operating rules for the reservoir model options within the NWM. Model experiments focus on a pilot reservoir domain-Lake Mendocino, CA, and its contributing watershed, the East Fork Russian River. This reservoir is modeled using United States Army Corps of Engineers (USACE) HEC-ResSim developed for application to examine forecast informed reservoir operations (FIRO) in the Russian River basin.

CADRE-SS, an in Silico Tool for Predicting Skin Sensitization Potential Based on Modeling of Molecular Interactions.

PubMed

Kostal, Jakub; Voutchkova-Kostal, Adelina

2016-01-19

Using computer models to accurately predict toxicity outcomes is considered to be a major challenge. However, state-of-the-art computational chemistry techniques can now be incorporated in predictive models, supported by advances in mechanistic toxicology and the exponential growth of computing resources witnessed over the past decade. The CADRE (Computer-Aided Discovery and REdesign) platform relies on quantum-mechanical modeling of molecular interactions that represent key biochemical triggers in toxicity pathways. Here, we present an external validation exercise for CADRE-SS, a variant developed to predict the skin sensitization potential of commercial chemicals. CADRE-SS is a hybrid model that evaluates skin permeability using Monte Carlo simulations, assigns reactive centers in a molecule and possible biotransformations via expert rules, and determines reactivity with skin proteins via quantum-mechanical modeling. The results were promising with an overall very good concordance of 93% between experimental and predicted values. Comparison to performance metrics yielded by other tools available for this endpoint suggests that CADRE-SS offers distinct advantages for first-round screenings of chemicals and could be used as an in silico alternative to animal tests where permissible by legislative programs.

Antihistone Properties of C1 Esterase Inhibitor Protect against Lung Injury.

PubMed

Wygrecka, Malgorzata; Kosanovic, Djuro; Wujak, Lukasz; Reppe, Katrin; Henneke, Ingrid; Frey, Helena; Didiasova, Miroslava; Kwapiszewska, Grazyna; Marsh, Leigh M; Baal, Nelli; Hackstein, Holger; Zakrzewicz, Dariusz; Müller-Redetzky, Holger C; de Maat, Steven; Maas, Coen; Nolte, Marc W; Panousis, Con; Schermuly, Ralph T; Seeger, Werner; Witzenrath, Martin; Schaefer, Liliana; Markart, Philipp

2017-07-15

Acute respiratory distress syndrome is characterized by alveolar epithelial cell injury, edema formation, and intraalveolar contact phase activation. To explore whether C1 esterase inhibitor (C1INH), an endogenous inhibitor of the contact phase, may protect from lung injury in vivo and to decipher the possible underlying mechanisms mediating protection. The ability of C1INH to control the inflammatory processes was studied in vitro and in vivo. Here, we demonstrate that application of C1INH alleviates bleomycin-induced lung injury via direct interaction with extracellular histones. In vitro, C1INH was found to bind all histone types. Interaction with histones was independent of its protease inhibitory activity, as demonstrated by the use of reactive-center-cleaved C1INH, but dependent on its glycosylation status. C1INH sialylated-N- and -O-glycans were not only essential for its interaction with histones but also to protect against histone-induced cell death. In vivo, histone-C1INH complexes were detected in bronchoalveolar lavage fluid from patients with acute respiratory distress syndrome and multiple models of lung injury. Furthermore, reactive-center-cleaved C1INH attenuated pulmonary damage evoked by intravenous histone instillation. Collectively, C1INH administration provides a new therapeutic option for disorders associated with histone release.

Planetary Wave-Tide Interactions in Atmosphere-Ionosphere Coupling, Xiaoli Zhang, Jeffrey M. Forbes, Astrid Maute, and Maura E. Hagan

NASA Astrophysics Data System (ADS)

Zhang, X.; Forbes, J. M.; Maute, A. I.

2017-12-01

Planetary Wave-Tide Interactions in Atmosphere-Ionosphere Coupling Xiaoli Zhang, Jeffrey M. Forbes, Astrid Maute, and Maura E. Hagan The existence of secondary waves in the mesosphere and thermosphere due to nonlinear interactions between atmospheric tides and longer-period waves have been revealed in both satellite data and in the National Center for Atmospheric Research (NCAR) Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIME-GCM). The longer-period waves include the quasi-2-day and 6-day westward-propagating "normal modes" of the atmosphere, and eastward-propagating ultra-fast Kelvin waves with periods between 2 and 4 days. The secondary waves add to both the temporal and longitude variability of the atmosphere beyond that associated with the linear superposition of the interacting waves, thus adding "complexity" to the system. Based on our knowledge of the processes governing atmosphere-ionosphere interactions, similar revelations are expected to occur in electric fields, vertical plasma drifts and F-region electron densities. Towards this end, examples of such ionospheric manifestations of wave-wave interactions in TIE-GCM simulations will be presented.

Simulations of Tidally Driven Formation of Binary Planet Systems

NASA Astrophysics Data System (ADS)

Murray, R. Zachary P.; Guillochon, James

2018-01-01

In the last decade there have been hundreds of exoplanets discovered by the Kepler, CoRoT and many other initiatives. This wealth of data suggests the possibility of detecting exoplanets with large satellites. This project seeks to model the interactions between orbiting planets using the FLASH hydrodynamics code developed by The Flash Center for Computational Science at University of Chicago. We model the encounters in a wide variety of encounter scenarios and initial conditions including variations in encounter depth, mass ratio, and encounter velocity and attempt to constrain what sorts of binary planet configurations are possible and stable.

Alternatives for jet engine control

NASA Technical Reports Server (NTRS)

Sain, M. K.

1981-01-01

Research centered on basic topics in the modeling and feedback control of nonlinear dynamical systems is reported. Of special interest were the following topics: (1) the role of series descriptions, especially insofar as they relate to questions of scheduling, in the control of gas turbine engines; (2) the use of algebraic tensor theory as a technique for parameterizing such descriptions; (3) the relationship between tensor methodology and other parts of the nonlinear literature; (4) the improvement of interactive methods for parameter selection within a tensor viewpoint; and (5) study of feedback gain representation as a counterpart to these modeling and parameterization ideas.

Scientific Benefits of Space Science Models Archiving at Community Coordinated Modeling Center

NASA Technical Reports Server (NTRS)

Kuznetsova, Maria M.; Berrios, David; Chulaki, Anna; Hesse, Michael; MacNeice, Peter J.; Maddox, Marlo M.; Pulkkinen, Antti; Rastaetter, Lutz; Taktakishvili, Aleksandre

2009-01-01

The Community Coordinated Modeling Center (CCMC) hosts a set of state-of-the-art space science models ranging from the solar atmosphere to the Earth's upper atmosphere. CCMC provides a web-based Run-on-Request system, by which the interested scientist can request simulations for a broad range of space science problems. To allow the models to be driven by data relevant to particular events CCMC developed a tool that automatically downloads data from data archives and transform them to required formats. CCMC also provides a tailored web-based visualization interface for the model output, as well as the capability to download the simulation output in portable format. CCMC offers a variety of visualization and output analysis tools to aid scientists in interpretation of simulation results. During eight years since the Run-on-request system became available the CCMC archived the results of almost 3000 runs that are covering significant space weather events and time intervals of interest identified by the community. The simulation results archived at CCMC also include a library of general purpose runs with modeled conditions that are used for education and research. Archiving results of simulations performed in support of several Modeling Challenges helps to evaluate the progress in space weather modeling over time. We will highlight the scientific benefits of CCMC space science model archive and discuss plans for further development of advanced methods to interact with simulation results.

Better Broader Impacts through National Science Foundation Centers

NASA Astrophysics Data System (ADS)

Campbell, K. M.

2010-12-01

National Science Foundation Science and Technology Centers (STCs) play a leading role in developing and evaluating “Better Broader Impacts”; best practices for recruiting a broad spectrum of American students into STEM fields and for educating these future professionals, as well as their families, teachers and the general public. With staff devoted full time to Broader Impacts activities, over the ten year life of a Center, STCs are able to address both a broad range of audiences and a broad range of topics. Along with other NSF funded centers, such as Centers for Ocean Sciences Education Excellence, Engineering Research Centers and Materials Research Science and Engineering Centers, STCs develop both models and materials that individual researchers can adopt, as well as, in some cases, direct opportunities for individual researchers to offer their disciplinary research expertise to existing center Broader Impacts Programs. The National Center for Earth-surface Dynamics is an STC headquartered at the University of Minnesota. NCED’s disciplinary research spans the physical, biological and engineering issues associated with developing an integrative, quantitative and predictive understanding of rivers and river basins. Funded in 2002, we have had the opportunity to partner with individuals and institutions ranging from formal to informal education and from science museums to Tribal and women’s colleges. We have developed simple table top physical models, complete museum exhibitions, 3D paper maps and interactive computer based visualizations, all of which have helped us communicate with this wide variety of learners. Many of these materials themselves or plans to construct them are available online; in many cases they have also been formally evaluated. We have also listened to the formal and informal educators with whom we partner, from whom we have learned a great deal about how to design Broader Impacts activities and programs. Using NCED as a case study, this session showcases NCED’s materials, approaches and lessons learned. We will also introduce the work of our sister STCs, whose disciplines span the STEM fields.

Emergence of fully gapped s++-wave and nodal d-wave states mediated by orbital and spin fluctuations in a ten-orbital model of KFe2Se2

NASA Astrophysics Data System (ADS)

Saito, Tetsuro; Onari, Seiichiro; Kontani, Hiroshi

2011-04-01

We study the superconducting state in recently discovered high-Tc superconductor KxFe2Se2 based on the ten-orbital Hubbard-Holstein model without hole pockets. When the Coulomb interaction is large, a spin-fluctuation-mediated d-wave state appears due to the nesting between electron pockets. Interestingly, the symmetry of the body-centered tetragonal structure in KxFe2Se2 requires the existence of nodes in the d-wave gap, although a fully gapped d-wave state is realized in the case of a simple tetragonal structure. In the presence of moderate electron-phonon interaction due to Fe-ion optical modes, however, orbital fluctuations give rise to the fully gapped s++-wave state without sign reversal. Therefore, both superconducting states are distinguishable by careful measurements of the gap structure or the impurity effect on Tc.

Modeling-Enabled Systems Nutritional Immunology

PubMed Central

Verma, Meghna; Hontecillas, Raquel; Abedi, Vida; Leber, Andrew; Tubau-Juni, Nuria; Philipson, Casandra; Carbo, Adria; Bassaganya-Riera, Josep

2016-01-01

This review highlights the fundamental role of nutrition in the maintenance of health, the immune response, and disease prevention. Emerging global mechanistic insights in the field of nutritional immunology cannot be gained through reductionist methods alone or by analyzing a single nutrient at a time. We propose to investigate nutritional immunology as a massively interacting system of interconnected multistage and multiscale networks that encompass hidden mechanisms by which nutrition, microbiome, metabolism, genetic predisposition, and the immune system interact to delineate health and disease. The review sets an unconventional path to apply complex science methodologies to nutritional immunology research, discovery, and development through “use cases” centered around the impact of nutrition on the gut microbiome and immune responses. Our systems nutritional immunology analyses, which include modeling and informatics methodologies in combination with pre-clinical and clinical studies, have the potential to discover emerging systems-wide properties at the interface of the immune system, nutrition, microbiome, and metabolism. PMID:26909350