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Sample records for affect numerous aspects

  1. Numerical aspects of compressible turbulence simulations

    NASA Astrophysics Data System (ADS)

    Honein, Albert Edward

    Nonlinear instabilities present a long standing hurdle for compact, high order, non dissipative, finite difference computation of compressible turbulence. The spectral-like accuracy of these schemes, while attractive, results in significant aliasing errors that corrupt the solution. As a result, successful simulations have been limited to moderate Reynolds numbers ( Re) and low-order or upwind schemes with inherent numerical dissipation. However, resorting to dissipative schemes in discretizing the nonlinear terms was shown to have a detrimental effect on turbulence. A recent LES approach is to abandon the subgrid model altogether and rely on the scheme dissipation to mimic the effect of small scales. A dissipative monotone integrated LES (MILES) algorithm based on a multidimensional flux-corrected transport (FCT) algorithm has been developed and tested for decaying compressible isotropic turbulence. Agreement with the benchmark experiments of Comte-Bellot and Corrsin is very sensitive to the parameters involved in the FCT algorithm, while the evolution of thermodynamic fluctuations do not compare well with direct numerical simulations. An under-resolved simulation of inviscid, compressible, isotropic turbulence at low Mach number is chosen as a severe benchmark to investigate the nonlinear stability properties of nondissipative schemes. The behavior of this benchmark is predicted by performing a fully de-aliased spectral simulation on a 32 3 grid with turbulent Mach number of Mto = 0.07. The kinetic energy and thermodynamic fluctuations are found to decay for finite Re, and remain constant at infinite Re for a long time before the occurrence of numerical shocks. Extending the proof of Kraichnan (Journal of the Acoustical Society of America, 27(3), 1955), this inviscid statistical equilibrium is demonstrated to be a consequence of the discrete equivalent of the Liouville theorem of classical statistical mechanics. Several existing non-dissipative methods are

  2. Radiation Hydrodynamics: Numerical Aspects and Applications

    NASA Astrophysics Data System (ADS)

    Dorfi, Ernst A.

    Introduction General Remarks on the Numerical Method Time Scales Length Scales Interaction Between Matter and Radiation Moving Fronts Basic Equations Radiation Hydrodynamics (RHD) Coupling Terms Closure Condition Opacity Equation of State Transport Theorem Solution Strategy Integral Form of the RHD Equations Symbolic Notation Moving Coordinates Implicit Discretization Time-centering Adaptive RHD Equations Discretization of Gradients and Divergence Terms Diffusion Advection Initial Conditions Boundary Conditions Artificial Viscosity Discrete RHD Equations Radiative Closure Condition Radiative Boundary Conditions Eddington Factor Adaptive Grids Basic Grid Properties Desired Resolution Spatial and Temporal Smoothing Grid Equation Grid Boundary Conditions Grid Motion Remarks on the Grid Equation First Example: Simple Test Function Second Example: Shock Tube Problem Initial Grid Distributions Further Computational Needs Rational Spline Interpolation CPU-Time Requirements Iteration Procedure and Matrix Inversion Structure of the Jacobi Matrix Time-Step Control Computational Examples Evolution of Supernova Remnants (SNRs) Nonlinear Stellar Pulsations Protostellar Collapse Dust-Driven Winds Radiative Transfer Discussion Internal Accuracy Problems Advantages and Disadvantages of the implict formulation Nuclear and Chemical Networks and Convection Multidimensional Versions Improvements and Further Recommendations References

  3. TOPICAL REVIEW: From geometry to numerics: interdisciplinary aspects in mathematical and numerical relativity

    NASA Astrophysics Data System (ADS)

    Jaramillo, José Luis; Valiente Kroon, Juan Antonio; Gourgoulhon, Eric

    2008-05-01

    This paper reviews some aspects in the current relationship between mathematical and numerical general relativity. Focus is placed on the description of isolated systems, with a particular emphasis on recent developments in the study of black holes. Ideas concerning asymptotic flatness, the initial-value problem, the constraint equations, evolution formalisms, geometric inequalities and quasi-local black hole horizons are discussed in light of the interaction between numerical and mathematical relativists.

  4. Aspects of manual wheelchair configuration affecting mobility: a review.

    PubMed

    Medola, Fausto Orsi; Elui, Valeria Meirelles Carril; Santana, Carla da Silva; Fortulan, Carlos Alberto

    2014-02-01

    Many aspects relating to equipment configuration affect users' actions in a manual wheelchair, determining the overall mobility performance. Since the equipment components and configuration determine both stability and mobility efficiency, configuring the wheelchair with the most appropriate set-up for individual users' needs is a difficult task. Several studies have shown the importance of seat/backrest assembly and the relative position of the rear wheels to the user in terms of the kinetics and kinematics of manual propulsion. More recently, new studies have brought to light evidence on the inertial properties of different wheelchair configurations. Further new studies have highlighted the handrim as a key component of wheelchair assembly, since it is the interface through which the user drives the chair. In light of the new evidence on wheelchair mechanics and propulsion kinetics and kinematics, this article presents a review of the most important aspects of wheelchair configuration that affect the users' actions and mobility.

  5. Aspects of Manual Wheelchair Configuration Affecting Mobility: A Review

    PubMed Central

    Medola, Fausto Orsi; Elui, Valeria Meirelles Carril; Santana, Carla da Silva; Fortulan, Carlos Alberto

    2014-01-01

    Many aspects relating to equipment configuration affect users’ actions in a manual wheelchair, determining the overall mobility performance. Since the equipment components and configuration determine both stability and mobility efficiency, configuring the wheelchair with the most appropriate set-up for individual users’ needs is a difficult task. Several studies have shown the importance of seat/backrest assembly and the relative position of the rear wheels to the user in terms of the kinetics and kinematics of manual propulsion. More recently, new studies have brought to light evidence on the inertial properties of different wheelchair configurations. Further new studies have highlighted the handrim as a key component of wheelchair assembly, since it is the interface through which the user drives the chair. In light of the new evidence on wheelchair mechanics and propulsion kinetics and kinematics, this article presents a review of the most important aspects of wheelchair configuration that affect the users’ actions and mobility. PMID:24648656

  6. Numerical Aspects of Solving Differential Equations: Laboratory Approach for Students.

    ERIC Educational Resources Information Center

    Witt, Ana

    1997-01-01

    Describes three labs designed to help students in a first course on ordinary differential equations with three of the most common numerical difficulties they might encounter when solving initial value problems with a numerical software package. The goal of these labs is to help students advance to independent work on common numerical anomalies.…

  7. Knowledge Engineering Aspects of Affective Bi-Modal Educational Applications

    NASA Astrophysics Data System (ADS)

    Alepis, Efthymios; Virvou, Maria; Kabassi, Katerina

    This paper analyses the knowledge and software engineering aspects of educational applications that provide affective bi-modal human-computer interaction. For this purpose, a system that provides affective interaction based on evidence from two different modes has been developed. More specifically, the system's inferences about students' emotions are based on user input evidence from the keyboard and the microphone. Evidence from these two modes is combined by a user modelling component that incorporates user stereotypes as well as a multi criteria decision making theory. The mechanism that integrates the inferences from the two modes has been based on the results of two empirical studies that were conducted in the context of knowledge engineering of the system. The evaluation of the developed system showed significant improvements in the recognition of the emotional states of users.

  8. Numerical magnitude affects temporal memories but not time encoding.

    PubMed

    Cai, Zhenguang G; Wang, Ruiming

    2014-01-01

    Previous research has suggested that the perception of time is influenced by concurrent magnitude information (e.g., numerical magnitude in digits, spatial distance), but the locus of the effect is unclear, with some findings suggesting that concurrent magnitudes such as space affect temporal memories and others suggesting that numerical magnitudes in digits affect the clock speed during time encoding. The current paper reports 6 experiments in which participants perceived a stimulus duration and then reproduced it. We showed that though a digit of a large magnitude (e.g., 9), relative to a digit of a small magnitude (e.g., 2), led to a longer reproduced duration when the digits were presented during the perception of the stimulus duration, such a magnitude effect disappeared when the digits were presented during the reproduction of the stimulus duration. These findings disconfirm the account that large numerical magnitudes accelerate the speed of an internal clock during time encoding, as such an account incorrectly predicts that a large numerical magnitude should lead to a shorter reproduced duration when presented during reproduction. Instead, the findings suggest that numerical magnitudes, like other magnitudes such as space, affect temporal memories when numerical magnitudes and temporal durations are concurrently held in memory. Under this account, concurrent numerical magnitudes have the chance to influence the memory of the perceived duration when they are presented during perception but not when they are presented at the reproduction stage.

  9. Taking Perspective: Personal Pronouns Affect Experiential Aspects of Literary Reading

    PubMed Central

    Burke, Michael; Hagoort, Peter; Willems, Roel M.

    2016-01-01

    Personal pronouns have been shown to influence cognitive perspective taking during comprehension. Studies using single sentences found that 3rd person pronouns facilitate the construction of a mental model from an observer’s perspective, whereas 2nd person pronouns support an actor’s perspective. The direction of the effect for 1st person pronouns seems to depend on the situational context. In the present study, we investigated how personal pronouns influence discourse comprehension when people read fiction stories and if this has consequences for affective components like emotion during reading or appreciation of the story. We wanted to find out if personal pronouns affect immersion and arousal, as well as appreciation of fiction. In a natural reading paradigm, we measured electrodermal activity and story immersion, while participants read literary stories with 1st and 3rd person pronouns referring to the protagonist. In addition, participants rated and ranked the stories for appreciation. Our results show that stories with 1st person pronouns lead to higher immersion. Two factors—transportation into the story world and mental imagery during reading—in particular showed higher scores for 1st person as compared to 3rd person pronoun stories. In contrast, arousal as measured by electrodermal activity seemed tentatively higher for 3rd person pronoun stories. The two measures of appreciation were not affected by the pronoun manipulation. Our findings underscore the importance of perspective for language processing, and additionally show which aspects of the narrative experience are influenced by a change in perspective. PMID:27192060

  10. [Alternative tactile system: C-fibers coding the affective aspect].

    PubMed

    Hua, Qing-Ping; Luo, Fei

    2007-10-01

    It has been accepted that human tactile sensation is mediated exclusively by large myelinated (Abeta) fibres. Nevertheless, recent studies indicated a dual mechanoceptive innervation of the skin in various mammals. Besides the known A fibers, the skin is also innervated by slow-conducting, low-threshold, small unmyelinated (C) afferents. These unmyelinated fibers respond vigorously to innocuous skin deformation, but poorly to rapid skin movement. They project to outer lamina II of spinal cord, and form synapse with the secondary sensory neurons. The latter then project to insular cortex via spinothalamic tracts. Functional magnetic resonance imaging (fMRI) studies showed that a slowly moving tactile stimulus along hairy skin produced a strong activation of the insular cortex. Pleasant touch has also been demonstrated to activate orbitofrontal cortex adjacent to areas responding to pleasant taste and smell. Overall, the response characteristics and activated brain regions suggest that they are related with the limbic system and affective aspect rather than tactile discriminative function.

  11. Aspects of Numerical Simulation of Circulation Control Airfoils

    NASA Technical Reports Server (NTRS)

    Swanson, R. C.; Rumsey, C. L.; Anders, S. G.

    2005-01-01

    The mass-averaged compressible Navier-Stokes equations are solved for circulation control airfoils. Numerical solutions are computed with a multigrid method that uses an implicit approximate factorization smoother. The effects of flow conditions (e.g., free-stream Mach number, angle of attack, momentum coefficient) and mesh on the prediction of circulation control airfoil flows are considered. In addition, the impact of turbulence modeling, including curvature effects and modifications to reduce eddy viscosity levels in the wall jet (i.e., Coanda flow), is discussed. Computed pressure distributions are compared with available experimental data.

  12. Numeric aspects in pitch identification: an fMRI study

    PubMed Central

    2011-01-01

    Background Pitch identification had yielded unique response patterns compared to other auditory skills. Selecting one out of numerous pitches distinguished this task from detecting a pitch ascent. Encoding of numerous stimuli had activated the intraparietal sulcus in the visual domain. Therefore, we hypothesized that numerosity encoding during pitch identification activates the intraparietal sulcus as well. Methods To assess pitch identification, the participants had to recognize a single pitch from a set of four possible pitches in each trial. Functional magnetic resonance imaging (fMRI) disentangled neural activation during this four-pitch-choice task from activation during pitch contour perception, tone localization, and pitch discrimination. Results Pitch identification induced bilateral activation in the intraparietal sulcus compared to pitch discrimination. Correct responses in pitch identification correlated with activation in the left intraparietal sulcus. Pitch contour perception activated the superior temporal gyrus conceivably due to the larger range of presented tones. The differentiation between pitch identification and tone localization failed. Activation in an ACC-hippocampus network distinguished pitch discrimination from pitch identification. Conclusion Pitch identification is distinguishable from pitch discrimination on the base of activation in the IPS. IPS activity during pitch identification may be the auditory counterpart of numerosity encoding in the visual domain. PMID:21392373

  13. Numerical aspects of spectral segmentation on polygonal grids

    SciTech Connect

    Matsekh, Anna; Skurikhin, Alexei; Prasad, Lakshman; Rosten, Edward

    2010-01-01

    The authors analyze numerical behavior of the spectral graph partitioning problem arising in the Normalized Cuts formulation of the image segmentation problem on polygonal grids. They make an observation that in the presence of rounding errors the eigenvector corresponding to the k-th smallest eigenvalue of the generalized graph Laplacian should contain more than k nodal domains that represent coherent segments in the image. As the result, the eigenvector corresponding to the trivial solution carries a wealth of information about the nodal domains in the image and can be used as an initial guess for the Krylov subspace eigensolver, while the computed eigenvector subspace, corresponding to just a few of the lowest eigenvalues of the graph Laplacian, will contain sufficient information for obtaining meaningful segmentation.

  14. Do Mitochondrial Replacement Techniques Affect Qualitative or Numerical Identity?

    PubMed

    Liao, S Matthew

    2017-01-01

    Mitochondrial replacement techniques (MRTs), known in the popular media as 'three-parent' or 'three-person' IVFs, have the potential to enable women with mitochondrial diseases to have children who are genetically related to them but without such diseases. In the debate regarding whether MRTs should be made available, an issue that has garnered considerable attention is whether MRTs affect the characteristics of an existing individual or whether they result in the creation of a new individual, given that MRTs involve the genetic manipulation of the germline. In other words, do MRTs affect the qualitative identity or the numerical identity of the resulting child? For instance, a group of panelists on behalf of the UK Human Fertilisation and Embryology Authority (HFEA) has claimed that MRTs affect only the qualitative identity of the resulting child, while the Working Group of the Nuffield Council on Bioethics (NCOB) has argued that MRTs would create a numerically distinct individual. In this article, I shall argue that MRTs do create a new and numerically distinct individual. Since my explanation is different from the NCOB's explanation, I shall also offer reasons why my explanation is preferable to the NCOB's explanation.

  15. Numerical studies of the reversed-field pinch at high aspect ratio

    NASA Astrophysics Data System (ADS)

    Sätherblom, H.-E.; Drake, J. R.

    1998-10-01

    The reversed field pinch (RFP) configuration at an aspect ratio of 8.8 is studied numerically by means of the three-dimensional magnetohydrodynamic code DEBS [D. D. Schnack et al., J. Comput. Phys. 70, 330 (1987)]. This aspect ratio is equal to that of the Extrap T1 experiment [S. Mazur et al., Nucl. Fusion 34, 427 (1994)]. A numerical study of a RFP with this level of aspect ratio requires extensive computer achievements and has hitherto not been performed. The results are compared with previous studies [Y. L. Ho et al., Phys. Plasmas 2, 3407 (1995)] of lower aspect ratio RFP configurations. In particular, an evaluation of the extrapolation to the aspect ratio of 8.8 made in this previous study shows that the extrapolation of the spectral spread, as well as most of the other findings, are confirmed. An important exception, however, is the magnetic diffusion coefficient, which is found to decrease with aspect ratio. Furthermore, an aspect ratio dependence of the magnetic energy and of the helicity of the RFP is found.

  16. Morphopathological aspects of healthy nails and nails affected by onychomycosis.

    PubMed

    Zaikovska, Olga; Pilmane, Mara; Kisis, Janis

    2014-09-01

    Patients of onychomycosis are common in the dermatology practice. Contemporary morphology creates opportunities to study the functional units of the nail when such infections occur from morphopathological point of view. There were 22 nails biopsies from onychomycosis patients taken for the research of morphopathological changes in the thickened nail plate affected by onychomycosis. Samples of cadaverous' nails were used as a control material. The material was stained with haematoxylin and eosin and immunohistochemical methods. Terminal deoxynucleotidyl transferase dUTP nick end labelling reaction and periodic acid-Schiff reaction were also performed. We found patchy hypertrophy in the granulose layer of the epidermis, with focal acanthosis. In the horn layer, we identified nests of parakeratosis of various sizes, with incorporations of homogenous and eosinophil masses. We found high levels of interleukin 6 and interleukin 10 positive cells in the nail bed and in the bloodstream. Interleukin 1, however, was not a part of any of the functional units of any of the nails. Significant amount of fibres containing human beta defensin-2 were found in the bed and plate of the nail. Therefore one can conclude that as regards the nails affected by onychomycosis, the most effective morphopathogenical processes include cytokine and defensin excretion occurrence in the nail bed.

  17. The Fifth Symposium on Numerical and Physical Aspects of Aerodynamic Flows

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This volume contains the papers presented at the Fifth Symposium on Numerical and Physical Aspects of Aerodynamic Flows, held at the California State University, Long Beach, from 13 to 15 January 1992. The symposium, like its immediate predecessors, considers the calculation of flows of relevance to aircraft, ships, and missiles with emphasis on the solution of two-dimensional unsteady and three-dimensional equations.

  18. Numerical investigation of flow on NACA4412 aerofoil with different aspect ratios

    NASA Astrophysics Data System (ADS)

    Demir, Hacımurat; Özden, Mustafa; Genç, Mustafa Serdar; Çağdaş, Mücahit

    2016-03-01

    In this study, the flow over NACA4412 was investigated both numerically and experimentally at a different Reynolds numbers. The experiments were carried out in a low speed wind tunnel with various angles of attack and different Reynolds numbers (25000 and 50000). Airfoil was manufactured using 3D printer with a various aspect ratios (AR = 1 and AR = 3). Smoke-wire and oil flow visualization methods were used to visualize the surface flow patterns. NACA4412 aerofoil was designed by using SOLIDWORKS. The structural grid of numerical model was constructed by ANSYS ICEM CFD meshing software. Furthermore, ANSYS FLUENT™ software was used to perform numerical calculations. The numerical results were compared with experimental results. Bubble formation was shown in CFD streamlines and smoke-wire experiments at z / c = 0.4. Furthermore, bubble shrunk at z / c = 0.2 by reason of the effects of tip vortices in both numerical and experimental studies. Consequently, it was seen that there was a good agreement between numerical and experimental results.

  19. Numerical analysis of the turbulent fluid flow through valves. Geometrical aspects influence at different positions

    NASA Astrophysics Data System (ADS)

    Rigola, J.; Aljure, D.; Lehmkuhl, O.; Pérez-Segarra, C. D.; Oliva, A.

    2015-08-01

    The aim of this paper is to carry out a group of numerical experiments over the fluid flow through a valve reed, using the CFD&HT code TermoFluids, an unstructured and parallel object-oriented CFD code for accurate and reliable solving of industrial flows. Turbulent flow and its solution is a very complex problem due to there is a non-lineal interaction between viscous and inertial effects further complicated by their rotational nature, together with the three-dimensionality inherent in these types of flow and the non-steady state solutions. In this work, different meshes, geometrical conditions and LES turbulence models (WALE, VMS, QR and SIGMA) are tested and results compared. On the other hand, the fluid flow boundary conditions are obtained by means of the numerical simulation model of hermetic reciprocating compressors tool, NEST-compressor code. The numerical results presented are based on a specific geometry, where the valve gap opening percentage is 11% of hole diameter and Reynolds numbers given by the one-dimensional model is 4.22 × 105, with density meshes of approximately 8 million CVs. Geometrical aspects related with the orifice's shape and its influence on fluid flow behaviour and pressure drop are analysed in detail, furthermore, flow results for different valve openings are also studied.

  20. Human-Computer Interaction: A Review of the Research on Its Affective and Social Aspects.

    ERIC Educational Resources Information Center

    Deaudelin, Colette; Dussault, Marc; Brodeur, Monique

    2003-01-01

    Discusses a review of 34 qualitative and non-qualitative studies related to affective and social aspects of student-computer interactions. Highlights include the nature of the human-computer interaction (HCI); the interface, comparing graphic and text types; and the relation between variables linked to HCI, mainly trust, locus of control,…

  1. Numerical simulation of the tip vortex off a low-aspect-ratio wing at transonic speed

    NASA Technical Reports Server (NTRS)

    Mansour, N. N.

    1984-01-01

    The viscous transonic flow around a low aspect ratio wing was computed by an implicit, three dimensional, thin-layer Navier-Stokes solver. The grid around the geometry of interest is obtained numerically as a solution to a Dirichlet problem for the cube. A low aspect ratio wing with large sweep, twist, taper, and camber is the chosen geometry. The topology chosen to wrap the mesh around the wing with good tip resolution is a C-O type mesh. The flow around the wing was computed for a free stream Mach number of 0.82 at an angle of attack of 5 deg. At this Mach number, an oblique shock forms on the upper surface of the wing, and a tip vortex and three dimensional flow separation off the wind surface are observed. Particle path lines indicate that the three dimensional flow separation on the wing surface is part of the roots of the tip vortex formation. The lifting of the tip vortex before the wing trailing edge is observed by following the trajectory of particles release around the wing tip.

  2. An investigation of the information propagation and entropy transport aspects of Stirling machine numerical simulation

    NASA Technical Reports Server (NTRS)

    Goldberg, Louis F.

    1992-01-01

    Aspects of the information propagation modeling behavior of integral machine computer simulation programs are investigated in terms of a transmission line. In particular, the effects of pressure-linking and temporal integration algorithms on the amplitude ratio and phase angle predictions are compared against experimental and closed-form analytic data. It is concluded that the discretized, first order conservation balances may not be adequate for modeling information propagation effects at characteristic numbers less than about 24. An entropy transport equation suitable for generalized use in Stirling machine simulation is developed. The equation is evaluated by including it in a simulation of an incompressible oscillating flow apparatus designed to demonstrate the effect of flow oscillations on the enhancement of thermal diffusion. Numerical false diffusion is found to be a major factor inhibiting validation of the simulation predictions with experimental and closed-form analytic data. A generalized false diffusion correction algorithm is developed which allows the numerical results to match their analytic counterparts. Under these conditions, the simulation yields entropy predictions which satisfy Clausius' inequality.

  3. ASPECT

    EPA Pesticide Factsheets

    Able to deploy within one hour of notification, EPA's Airborne Spectral Photometric Environmental Collection Technology (ASPECT) is the nation’s only airborne real-time chemical and radiological detection, infrared and photographic imagery platform.

  4. A numerical investigation of nonlinear aeroelastic effects on flexible high aspect ratio wings

    NASA Astrophysics Data System (ADS)

    Garcia, Joseph Avila

    2002-01-01

    A nonlinear aeroelastic analysis that couples a nonlinear structural model with an Euler/Navier-Stokes flow solver is developed for flexible high aspect ratio wings. To model the nonlinear structural characteristics of flexible high aspect ratio wings, a two-dimensional geometric nonlinear methodology, based on a 6 degree-of-freedom (DOF) beam finite element, is extended to three dimensions based on a 12 DOF beam finite element. The three-dimensional analysis is developed in order to capture the nonlinear torsion-bending coupling, which is not accounted for by the two-dimensional nonlinear methodology. Validation of the three-dimensional nonlinear structural approach against experimental data shows that the approach accurately predicts the geometric nonlinear bending and torsion due to bending for configurations of general interest. Torsion is slightly overpredicted in extreme cases and higher order modeling is then required. The three-dimensional nonlinear beam model is then coupled with an Euler/Navier-Stokes computational fluid dynamics (CFD) analysis. Solving the equations numerically for the two nonlinear systems results in an increase in computational time and cost needed to perform the aeroelastic analysis. To improve the computational efficiency of the nonlinear aeroelastic analysis, the nonlinear structural approach uses a second-order accurate predictor-corrector methodology to solve for the displacements. Static aeroelastic results are presented for an unswept and swept high aspect ratio wing in the transonic flow regime, using the developed nonlinear aeroelastic methodology. Unswept wing results show a reversal in twist due to the nonlinear torsion-bending coupling effects. Specifically, the torsional moments due to drag become large enough to cause the wing twist rotations to washin the wing tips, while the linear results show a washout twist rotation. The nonlinear twist results are attributed to the large bending displacements coupled with the large

  5. Impact of vegetation on stability of slopes subjected to rainfall - numerical aspect

    NASA Astrophysics Data System (ADS)

    Switala, Barbara Maria; Tamagnini, Roberto; Sudan Acharya, Madhu; Wu, Wei

    2015-04-01

    Recent years brought a significant development of soil bioengineering methods, considered as an ecological and economically effective measure for slope stabilization. This work aims to show the advantages of the soil bioengineering solutions for a slope subjected to a heavy rainfall, with the help of a numerical model, which integrates most of the significant plant and slope features. There are basically two different ways in which vegetation can affect stability of a slope: root reinforcement (mechanical impact) and root water uptake (evapotranspiration). In the numerical model, the first factor is modelled using the Cam-Clay model extended for unsaturated conditions by Tamagnini (2004). The original formulation of a constitutive model is modified by introducing an additional constitutive parameter, which causes an expansion of the yield surface as a consequence of an increase in root mass in a representative soil element. The second factor is the root water uptake, which is defined as a volumetric sink term in the continuity equation of groundwater flow. Water removal from the soil mass causes an increase in suction in the vicinity of the root zone, which leads to an increase in the soil cohesion and provides additional strength to the soil-root composite. The developed numerical model takes into account the above mentioned effects of plants and thus considers the multi-phase nature of the soil-plant-water relationship. Using the developed method, stability of some vegetated and non-vegetated slopes subjected to rainfall are investigated. The performance of each slope is evaluated by the time at which slope failure occurs. Different slope geometries and soil mechanical and hydrological properties are considered. Comparison of the results obtained from the analyses of vegetated and non-vegetated slopes leads to the conclusion, that the use of soil bioengineering methods for slope stabilization can be effective and can significantly delay the occurrence of a

  6. Numerical modeling on air quality in an urban environment with changes of the aspect ratio and wind direction.

    PubMed

    Yassin, Mohamed F

    2013-06-01

    Due to heavy traffic emissions within an urban environment, air quality during the last decade becomes worse year by year and hazard to public health. In the present work, numerical modeling of flow and dispersion of gaseous emissions from vehicle exhaust in a street canyon were investigated under changes of the aspect ratio and wind direction. The three-dimensional flow and dispersion of gaseous pollutants were modeled using a computational fluid dynamics (CFD) model which was numerically solved using Reynolds-averaged Navier-Stokes (RANS) equations. The diffusion flow field in the atmospheric boundary layer within the street canyon was studied for different aspect ratios (W/H=1/2, 3/4, and 1) and wind directions (θ=90°, 112.5°, 135°, and 157.5°). The numerical models were validated against wind tunnel results to optimize the turbulence model. The numerical results agreed well with the wind tunnel results. The simulation demonstrated that the minimum concentration at the human respiration height within the street canyon was on the windward side for aspect ratios W/H=1/2 and 1 and wind directions θ=112.5°, 135°, and 157.5°. The pollutant concentration level decreases as the wind direction and aspect ratio increase. The wind velocity and turbulence intensity increase as the aspect ratio and wind direction increase.

  7. Software Aspects of IEEE Floating-Point Computations for Numerical Applications in High Energy Physics

    ScienceCinema

    None

    2016-07-12

    Floating-point computations are at the heart of much of the computing done in high energy physics. The correctness, speed and accuracy of these computations are of paramount importance. The lack of any of these characteristics can mean the difference between new, exciting physics and an embarrassing correction. This talk will examine practical aspects of IEEE 754-2008 floating-point arithmetic as encountered in HEP applications. After describing the basic features of IEEE floating-point arithmetic, the presentation will cover: common hardware implementations (SSE, x87) techniques for improving the accuracy of summation, multiplication and data interchange compiler options for gcc and icc affecting floating-point operations hazards to be avoided About the speaker Jeffrey M Arnold is a Senior Software Engineer in the Intel Compiler and Languages group at Intel Corporation. He has been part of the Digital->Compaq->Intel compiler organization for nearly 20 years; part of that time, he worked on both low- and high-level math libraries. Prior to that, he was in the VMS Engineering organization at Digital Equipment Corporation. In the late 1980s, Jeff spent 2½ years at CERN as part of the CERN/Digital Joint Project. In 2008, he returned to CERN to spent 10 weeks working with CERN/openlab. Since that time, he has returned to CERN multiple times to teach at openlab workshops and consult with various LHC experiments. Jeff received his Ph.D. in physics from Case Western Reserve University.

  8. Chronic loss of melanin-concentrating hormone affects motivational aspects of feeding in the rat.

    PubMed

    Mul, Joram D; la Fleur, Susanne E; Toonen, Pim W; Afrasiab-Middelman, Anthonieke; Binnekade, Rob; Schetters, Dustin; Verheij, Michel M M; Sears, Robert M; Homberg, Judith R; Schoffelmeer, Anton N M; Adan, Roger A H; DiLeone, Ralph J; De Vries, Taco J; Cuppen, Edwin

    2011-05-05

    Current epidemic obesity levels apply great medical and financial pressure to the strenuous economy of obesity-prone cultures, and neuropeptides involved in body weight regulation are regarded as attractive targets for a possible treatment of obesity in humans. The lateral hypothalamus and the nucleus accumbens shell (AcbSh) form a hypothalamic-limbic neuropeptide feeding circuit mediated by Melanin-Concentrating Hormone (MCH). MCH promotes feeding behavior via MCH receptor-1 (MCH1R) in the AcbSh, although this relationship has not been fully characterized. Given the AcbSh mediates reinforcing properties of food, we hypothesized that MCH modulates motivational aspects of feeding.Here we show that chronic loss of the rat MCH-precursor Pmch decreased food intake predominantly via a reduction in meal size during rat development and reduced high-fat food-reinforced operant responding in adult rats. Moreover, acute AcbSh administration of Neuropeptide-GE and Neuropeptide-EI (NEI), both additional neuropeptides derived from Pmch, or chronic intracerebroventricular infusion of NEI, did not affect feeding behavior in adult pmch(+/+) or pmch(-/-) rats. However, acute administration of MCH to the AcbSh of adult pmch(-/-) rats elevated feeding behavior towards wild type levels. Finally, adult pmch(-/-) rats showed increased ex vivo electrically evoked dopamine release and increased limbic dopamine transporter levels, indicating that chronic loss of Pmch in the rat affects the limbic dopamine system.Our findings support the MCH-MCH1R system as an amplifier of consummatory behavior, confirming this system as a possible target for the treatment of obesity. We propose that MCH-mediated signaling in the AcbSh positively mediates motivational aspects of feeding behavior. Thereby it provides a crucial signal by which hypothalamic neural circuits control energy balance and guide limbic brain areas to enhance motivational or incentive-related aspects of food consumption.

  9. Chronic Loss of Melanin-Concentrating Hormone Affects Motivational Aspects of Feeding in the Rat

    PubMed Central

    Mul, Joram D.; la Fleur, Susanne E.; Toonen, Pim W.; Afrasiab-Middelman, Anthonieke; Binnekade, Rob; Schetters, Dustin; Verheij, Michel M. M.; Sears, Robert M.; Homberg, Judith R.; Schoffelmeer, Anton N. M.; Adan, Roger A. H.; DiLeone, Ralph J.; De Vries, Taco J.; Cuppen, Edwin

    2011-01-01

    Current epidemic obesity levels apply great medical and financial pressure to the strenuous economy of obesity-prone cultures, and neuropeptides involved in body weight regulation are regarded as attractive targets for a possible treatment of obesity in humans. The lateral hypothalamus and the nucleus accumbens shell (AcbSh) form a hypothalamic-limbic neuropeptide feeding circuit mediated by Melanin-Concentrating Hormone (MCH). MCH promotes feeding behavior via MCH receptor-1 (MCH1R) in the AcbSh, although this relationship has not been fully characterized. Given the AcbSh mediates reinforcing properties of food, we hypothesized that MCH modulates motivational aspects of feeding. Here we show that chronic loss of the rat MCH-precursor Pmch decreased food intake predominantly via a reduction in meal size during rat development and reduced high-fat food-reinforced operant responding in adult rats. Moreover, acute AcbSh administration of Neuropeptide-GE and Neuropeptide-EI (NEI), both additional neuropeptides derived from Pmch, or chronic intracerebroventricular infusion of NEI, did not affect feeding behavior in adult pmch+/+ or pmch−/− rats. However, acute administration of MCH to the AcbSh of adult pmch−/− rats elevated feeding behavior towards wild type levels. Finally, adult pmch−/− rats showed increased ex vivo electrically evoked dopamine release and increased limbic dopamine transporter levels, indicating that chronic loss of Pmch in the rat affects the limbic dopamine system. Our findings support the MCH-MCH1R system as an amplifier of consummatory behavior, confirming this system as a possible target for the treatment of obesity. We propose that MCH-mediated signaling in the AcbSh positively mediates motivational aspects of feeding behavior. Thereby it provides a crucial signal by which hypothalamic neural circuits control energy balance and guide limbic brain areas to enhance motivational or incentive-related aspects of food consumption. PMID

  10. The 26 July 2005 heavy rainfall event over Mumbai: numerical modeling aspects

    NASA Astrophysics Data System (ADS)

    Sahany, Sandeep; Venugopal, V.; Nanjundiah, Ravi S.

    2010-12-01

    The performance of the Advanced Regional Prediction System (ARPS) in simulating an extreme rainfall event is evaluated, and subsequently the physical mechanisms leading to its initiation and sustenance are explored. As a case study, the heavy precipitation event that led to 65 cm of rainfall accumulation in a span of around 6 h (1430 LT-2030 LT) over Santacruz (Mumbai, India), on 26 July, 2005, is selected. Three sets of numerical experiments have been conducted. The first set of experiments (EXP1) consisted of a four-member ensemble, and was carried out in an idealized mode with a model grid spacing of 1 km. In spite of the idealized framework, signatures of heavy rainfall were seen in two of the ensemble members. The second set (EXP2) consisted of a five-member ensemble, with a four-level one-way nested integration and grid spacing of 54, 18, 6 and 1 km. The model was able to simulate a realistic spatial structure with the 54, 18, and 6 km grids; however, with the 1 km grid, the simulations were dominated by the prescribed boundary conditions. The third and final set of experiments (EXP3) consisted of a five-member ensemble, with a four-level one-way nesting and grid spacing of 54, 18, 6, and 2 km. The Scaled Lagged Average Forecasting (SLAF) methodology was employed to construct the ensemble members. The model simulations in this case were closer to observations, as compared to EXP2. Specifically, among all experiments, the timing of maximum rainfall, the abrupt increase in rainfall intensities, which was a major feature of this event, and the rainfall intensities simulated in EXP3 (at 6 km resolution) were closest to observations. Analysis of the physical mechanisms causing the initiation and sustenance of the event reveals some interesting aspects. Deep convection was found to be initiated by mid-tropospheric convergence that extended to lower levels during the later stage. In addition, there was a high negative vertical gradient of equivalent potential

  11. Epidemiological aspects of rheumatoid arthritis patients affected by oral bisphosphonate-related osteonecrosis of the jaws

    PubMed Central

    2012-01-01

    This literature review aims to evaluate the epidemiologic profile of patients with rheumatoid arthritis (RA) that developed a bisphosphonate-related osteonecrosis that affect the jaws (BRONJ), including demographic aspects, as well as clinical and therapeutic issues. A search of PUBMED/MEDLINE, Scopus, and Cochrane databases from January 2003 to September 2011 was conducted with the objective of identifying publications that contained case reports regarding oral BRONJ in RA patients. Patients with RA who develop oral BRONJ are usually women above 60 years taking steroids and long-term alendronate. Most of them have osteoporosis, and lesions, triggered by dental procedures, are usually detected at stage II in the mandible. Although there is no accepted treatment protocol, these patients seem to have better outcomes with conservative approaches that include antibiotic therapy, chlorhexidine, and drug discontinuation. PMID:22376948

  12. Numerical Study of the Effect of the Sample Aspect Ratio on the Ductility of Bulk Metallic Glasses (BMGs) Under Compression

    NASA Astrophysics Data System (ADS)

    Jiang, Yunpeng

    2016-05-01

    In this article, a systematic numerical study was conducted to study the detailed shear banding evolution in bulk metallic glasses (BMGs) with various sample aspect ratios under uniaxial compression, and whereby the effect of the sample aspect ratio on the compressive ductility was elucidated. A finite strain viscoelastic model was employed to describe the shear banding nucleation, growth, and coalescence in BMG samples with the help of Anand and Su's theory, which was incorporated into the ABAQUS finite element method code as a user material subroutine VUMAT. The present numerical method was first verified by comparing with the corresponding experimental results, and then parameter analysis was performed to discuss the impact of microstructure parameters on the predicted results. The present modeling will shed some light on enhancing the toughness of BMG structures in the engineering applications.

  13. Numerical magnitude affects online execution, and not planning of visuomotor control.

    PubMed

    Namdar, Gal; Ganel, Tzvi

    2017-01-20

    Recent literature has established a directional influence of irrelevant numerical magnitude on actions performed toward neutral objects. For example, fingers' aperture during grasping is larger when associated with large compared with small numerical digits. This interaction between symbolic magnitude and visuomotor control has been attributed to the planning stage of the action prior to motor execution. However, this assumption has not been directly tested. In two experiments, we tested whether the effects of numerical magnitude on grasping derive from action planning or from action execution. Participants were asked to grasp an object following a short visual (Experiment 1) or auditory (Experiment 2) presentation of small (1/2) or large (8/9) digits. Grasping was performed under either closed-loop (CL) or open-loop (OL) visuomotor control, for which online vision was prevented during action execution. Digit magnitude affected grip apertures in the CL condition, when online vision was allowed. However, magnitude had no effects on grip aperture in the OL condition. This pattern of results strongly suggests that the processing of numerical magnitude originates from interactions between numerical magnitude and real object size during online motor execution. Unlike previously assumed, the findings also suggest that the effect of magnitude on visuomotor control is not likely to be attributed to the motor planning stage prior to action initiation.

  14. Cognitive and Affective Aspects of Creative Option Generation in Everyday Life Situations

    PubMed Central

    Schweizer, T. Sophie; Schmalenberger, Katja M.; Eisenlohr-Moul, Tory A.; Mojzisch, Andreas; Kaiser, Stefan; Funke, Joachim

    2016-01-01

    Which factors influence a human being’s ability to develop new perspectives and be creative? This ability is pivotal for any context in which new cognitions are required, such as innovative endeavors in science and art, or psychotherapeutic settings. In this article, we seek to bring together two research programs investigating the generation of creative options: On the one hand, research on option generation in the decision-making literature and, on the other hand, cognitive and clinical creativity research. Previous decision-making research has largely neglected the topic of generating creative options. Experiments typically provided participants with a clear set of options to choose from, but everyday life situations are less structured and allow countless ways to react. Before choosing an option, agents have to self-generate a set of options to choose from. Such option generation processes have only recently moved to the center of attention. The present study examines the creative quality of self-generated options in daily life situations. A student sample (N = 48) generated options for action in 70 briefly described everyday life scenarios. We rated the quality of the options on three dimensions of creativity- originality, feasibility, and divergence -and linked these qualities to option generation fluency (speed and number of generated options), situational features like the familiarity and the affective valence of the situation in which the options were generated, and trait measures of cognitive performance. We found that when situations were familiar to the participant, greater negative affective valence of the situation was associated with more originality and divergence of generated options. We also found that a higher option generation fluency was associated with a greater maximal originality of options. We complete our article with a joint research agenda for researchers in the decision-making field focusing on option generation and, on the other hand

  15. Numerical study of flow and thermal behaviour of lid-driven flows in cavities of small aspect ratios

    NASA Astrophysics Data System (ADS)

    Chen, Chin-Lung; Cheng, Chin-Hsiang

    2006-11-01

    Numerical study has been performed to investigate the effects of cavity shape on flow and heat transfer characteristics of the lid-driven cavity flows. Dependence of flow and thermal behaviour on the aspect ratio of the cavities is also evaluated. Three types of the cross-sectional shape, namely, circular, triangular, and rectangular, and four aspect ratios, 0.133, 0.207, 0.288, and 0.5, are taken into account to construct twelve possible combinations; however, attention is focused on the small-aspect-ratio situations. Value of the Reynolds number considered in this study is varied between 100 and 1800. For the cases considered in this study a major clockwise vortex driven by the moving lid prevailing in the cavity is always observed. When the Reynolds number is fixed, the rectangular cavity produces strongest lid-driven flow, and the triangular cavity weakest. For the cases at small aspect ratio and low Reynolds number, the streamlines appear symmetric fore-and-aft with respect to the central line at x/L = 0.5. Data for the local and average Nusselt numbers are also provided. For rectangular cavities, it is observed that case 1/5R produces the highest average Nusselt number at any Reynolds number. Among the twelve possible geometric cases considered herein, the highest and lowest average Nusselt numbers are found with cases 1/6T and 1/2C, respectively.

  16. Pain and dental implantology: sensory quantification and affective aspects. Part I: At the private dental office.

    PubMed

    Muller, E; Ríos Calvo, M P

    2001-01-01

    After an extensive review of the dental literature, few articles were found related to pain and implantology. Management of orofacial pain has traditionally been a difficult challenge for the dental-medical profession. Patients may be afraid of dental pain, particularly in cases of dental implantology. Therefore, a study to obtain more conclusive data was developed. Taking into account that the perception of pain and the threshold of pain vary among individuals, a 2-year clinical study was established in private practice utilizing a verbal method (double-blind). The study was used to quantify sensory and affective aspects of pain associated with dental implantology on 75 patients in a private dental office. All of the implants were placed by the same clinician. Data were recorded following a Pain Data Sheet designed for this particular study. The aim of this study was to obtain different aspects of data as follows: 1) Fear of the dentist and fear of dental implant procedures utilizing a descriptive scale of 1 to 10, with 1 indicative of no fear. 2) Dental areas and ridges: Dental pain, pain in edentulous areas, and pain in the implanted area utilizing a scale of 0 to 8, with 0 indicative of no pain. 3) Function and pain: during mastication, swallowing, speech, yawning, opening, closing, and lateral excursions and indication of cervical pain or back pain, each calibrated by the presence or absence of pain. 4) Palpation and pain of the temporomandibular joint, the temporal muscle, the area of the pterygoid muscles, masseter muscle, and sternocleidomastoid muscle, all calibrated on the indication of presence or absence of pain. 5) Others: ear pain, neuralgia, headaches, edema, and hematoma, calibrated on the basis of presence or absence. The aforementioned factors were evaluated immediately before surgery and after surgery, at 24 hours, and during a follow up for a period of 2 years at intervals of 1 week; 1, 2, 3, 4, and 6 months; and 1 and 2 years after surgery

  17. RESONANT ABSORPTION OF TRANSVERSE OSCILLATIONS AND ASSOCIATED HEATING IN A SOLAR PROMINENCE. II. NUMERICAL ASPECTS

    SciTech Connect

    Antolin, P.; Okamoto, T. J.; Doorsselaere, T. Van; Yokoyama, T.

    2015-08-10

    Transverse magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere and may be responsible for generating the Sun’s million-degree outer atmosphere. However, direct evidence of the dissipation process and heating from these waves remains elusive. Through advanced numerical simulations combined with appropriate forward modeling of a prominence flux tube, we provide the observational signatures of transverse MHD waves in prominence plasmas. We show that these signatures are characterized by a thread-like substructure, strong transverse dynamical coherence, an out-of-phase difference between plane-of-the-sky motions and line-of-sight velocities, and enhanced line broadening and heating around most of the flux tube. A complex combination between resonant absorption and Kelvin–Helmholtz instabilities (KHIs) takes place in which the KHI extracts the energy from the resonant layer and dissipates it through vortices and current sheets, which rapidly degenerate into turbulence. An inward enlargement of the boundary is produced in which the turbulent flows conserve the characteristic dynamics from the resonance, therefore guaranteeing detectability of the resonance imprints. We show that the features described in the accompanying paper through coordinated Hinode and Interface Region Imaging Spectrograph observations match the numerical results well.

  18. Numerical simulation of transonic separated flows over low-aspect ratio wings

    NASA Technical Reports Server (NTRS)

    Kaynak, U.; Holst, T. L.; Sorenson, R. L.; Cantwell, B. J.

    1986-01-01

    Transonic flow fields about a low-aspect-ratio advanced technology wing have been computed using a viscous/inviscid zonal approach. The flow field near the wing where viscous effects are important was solved using the 'Reynolds-Averaged Navier-Stokes Equations' in 'thin-layer' form. The Euler equations were used to determine the flow field in regions away from the wing where viscous effects are insignificant. A zonal grid using an H-H topology was generated around the wing by first solving a set of Poisson's equations for the global grid. This grid was then subdivided into separate zones of viscous or inviscid flow as suggested by the flow physics. A series of flow cases were computed and compared with corresponding sets of experimental data. All cases showed good agreement with experiment in terms of the pressure field. Also, a good correlation between computed separated surface flow and experimental oil flow was obtained.

  19. Natural selection affects multiple aspects of genetic variation at putatively neutral sites across the human genome.

    PubMed

    Lohmueller, Kirk E; Albrechtsen, Anders; Li, Yingrui; Kim, Su Yeon; Korneliussen, Thorfinn; Vinckenbosch, Nicolas; Tian, Geng; Huerta-Sanchez, Emilia; Feder, Alison F; Grarup, Niels; Jørgensen, Torben; Jiang, Tao; Witte, Daniel R; Sandbæk, Annelli; Hellmann, Ines; Lauritzen, Torsten; Hansen, Torben; Pedersen, Oluf; Wang, Jun; Nielsen, Rasmus

    2011-10-01

    A major question in evolutionary biology is how natural selection has shaped patterns of genetic variation across the human genome. Previous work has documented a reduction in genetic diversity in regions of the genome with low recombination rates. However, it is unclear whether other summaries of genetic variation, like allele frequencies, are also correlated with recombination rate and whether these correlations can be explained solely by negative selection against deleterious mutations or whether positive selection acting on favorable alleles is also required. Here we attempt to address these questions by analyzing three different genome-wide resequencing datasets from European individuals. We document several significant correlations between different genomic features. In particular, we find that average minor allele frequency and diversity are reduced in regions of low recombination and that human diversity, human-chimp divergence, and average minor allele frequency are reduced near genes. Population genetic simulations show that either positive natural selection acting on favorable mutations or negative natural selection acting against deleterious mutations can explain these correlations. However, models with strong positive selection on nonsynonymous mutations and little negative selection predict a stronger negative correlation between neutral diversity and nonsynonymous divergence than observed in the actual data, supporting the importance of negative, rather than positive, selection throughout the genome. Further, we show that the widespread presence of weakly deleterious alleles, rather than a small number of strongly positively selected mutations, is responsible for the correlation between neutral genetic diversity and recombination rate. This work suggests that natural selection has affected multiple aspects of linked neutral variation throughout the human genome and that positive selection is not required to explain these observations.

  20. Numerical study of thermal radiation and thermophoresis on peristalsis with rotational aspects

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Zahir, H.; Alsaedi, A.; Ahmad, B.

    The present work concentrates for the impact of thermal radiation on peristaltic transport of viscous fluid in a rotating channel. Both fluid and channel are in a state of rigid body rotation. The influences of thermophoresis and chemical reaction are taken into account. Convective conditions for heat and mass transfer in the formulation are adopted. In addition, the non-uniform heat source/sink effect is included in heat transfer analysis. Exact solutions for stream function and temperature are obtained. Numerical solution for concentration of the developed mathematical model are obtained by considering low Reynolds number and long wavelength. The effects of emerging physical parameters are analyzed through graphical illustrations. It is found that the influence of thermophoretic and thermal radiation parameters on the temperature and concentration are quite opposite. Further heat transfer coefficient decays when rotation is increased.

  1. A Review about Functional Illiteracy: Definition, Cognitive, Linguistic, and Numerical Aspects.

    PubMed

    Vágvölgyi, Réka; Coldea, Andra; Dresler, Thomas; Schrader, Josef; Nuerk, Hans-Christoph

    2016-01-01

    Formally, availability of education for children has increased around the world over the last decades. However, despite having a successful formal education career, adults can become functional illiterates. Functional illiteracy means that a person cannot use reading, writing, and calculation skills for his/her own and the community's development. Functional illiteracy has considerable negative effects not only on personal development, but also in economic and social terms. Although functional illiteracy has been highly publicized in mass media in the recent years, there is limited scientific knowledge about the people termed functional illiterates; definition, assessment, and differential diagnoses with respect to related numerical and linguistic impairments are rarely studied and controversial. The first goal of our review is to give a comprehensive overview of the research on functional illiteracy by describing gaps in knowledge within the field and to outline and address the basic questions concerning who can be considered as functional illiterates: (1) Do they possess basic skills? (2) In which abilities do they have the largest deficits? (3) Are numerical and linguistic deficits related? (4) What is the fundamental reason for their difficulties? (5) Are there main differences between functional illiterates, illiterates, and dyslexics? We will see that despite partial evidence, there is still much research needed to answer these questions. Secondly, we emphasize the timeliness for a new and more precise definition that results in uniform sampling, better diagnosis, conclusion, and intervention. We propose the following working definition as the result of the review: functional illiteracy is the incapability to understand complex texts despite adequate schooling, age, language skills, elementary reading skills, and IQ. These inabilities must also not be fully explained by sensory, domain-general cognitive, neurological or mental disorders. In sum, we suggest

  2. A Review about Functional Illiteracy: Definition, Cognitive, Linguistic, and Numerical Aspects

    PubMed Central

    Vágvölgyi, Réka; Coldea, Andra; Dresler, Thomas; Schrader, Josef; Nuerk, Hans-Christoph

    2016-01-01

    Formally, availability of education for children has increased around the world over the last decades. However, despite having a successful formal education career, adults can become functional illiterates. Functional illiteracy means that a person cannot use reading, writing, and calculation skills for his/her own and the community’s development. Functional illiteracy has considerable negative effects not only on personal development, but also in economic and social terms. Although functional illiteracy has been highly publicized in mass media in the recent years, there is limited scientific knowledge about the people termed functional illiterates; definition, assessment, and differential diagnoses with respect to related numerical and linguistic impairments are rarely studied and controversial. The first goal of our review is to give a comprehensive overview of the research on functional illiteracy by describing gaps in knowledge within the field and to outline and address the basic questions concerning who can be considered as functional illiterates: (1) Do they possess basic skills? (2) In which abilities do they have the largest deficits? (3) Are numerical and linguistic deficits related? (4) What is the fundamental reason for their difficulties? (5) Are there main differences between functional illiterates, illiterates, and dyslexics? We will see that despite partial evidence, there is still much research needed to answer these questions. Secondly, we emphasize the timeliness for a new and more precise definition that results in uniform sampling, better diagnosis, conclusion, and intervention. We propose the following working definition as the result of the review: functional illiteracy is the incapability to understand complex texts despite adequate schooling, age, language skills, elementary reading skills, and IQ. These inabilities must also not be fully explained by sensory, domain-general cognitive, neurological or mental disorders. In sum, we suggest

  3. An elastomeric material for facial prostheses: synthesis, experimental and numerical testing aspects.

    PubMed

    Bellamy, Kathryn; Limbert, G; Waters, Mark G; Middleton, J

    2003-12-01

    Current materials used for maxillofacial prostheses are far from ideal and there is a need for new improved materials which better simulate the tissues they are replacing. This study was based on a mixed experimental/analytical/numerical approach. A new polymeric material was developed to provide a better alternative to the materials currently used in maxillofacial prosthetics. A series of experimental tensile tests were performed in order to characterise the tensile properties of the material. A Mooney-Rivlin type hyperelastic formulation was chosen to describe the constitutive behaviour of the polymer which operates at the finite strain regime. The material parameters (two) of the constitutive law were identified with the experimental data. The Mooney-Rivlin material was found to be suitable to represent accurately the mechanical behaviour of the polymer up to 50% strain as shown by the excellent agreement between analytical and experimental results. An FE model reproducing all the characteristics of the experimental tensile tests was built and a series of three FE analyses were conducted and has proven the proper finite element implementation of the material model. This preliminary study will serve as a basis to introduce more complex features such as viscoelasticity and wrinkling of the soft polymeric structure in order to optimise the performances of the final prosthetic material.

  4. Numerical Aspects of Atomic Physics: Helium Basis Sets and Matrix Diagonalization

    NASA Astrophysics Data System (ADS)

    Jentschura, Ulrich; Noble, Jonathan

    2014-03-01

    We present a matrix diagonalization algorithm for complex symmetric matrices, which can be used in order to determine the resonance energies of auto-ionizing states of comparatively simple quantum many-body systems such as helium. The algorithm is based in multi-precision arithmetic and proceeds via a tridiagonalization of the complex symmetric (not necessarily Hermitian) input matrix using generalized Householder transformations. Example calculations involving so-called PT-symmetric quantum systems lead to reference values which pertain to the imaginary cubic perturbation (the imaginary cubic anharmonic oscillator). We then proceed to novel basis sets for the helium atom and present results for Bethe logarithms in hydrogen and helium, obtained using the enhanced numerical techniques. Some intricacies of ``canned'' algorithms such as those used in LAPACK will be discussed. Our algorithm, for complex symmetric matrices such as those describing cubic resonances after complex scaling, is faster than LAPACK's built-in routines, for specific classes of input matrices. It also offer flexibility in terms of the calculation of the so-called implicit shift, which is used in order to ``pivot'' the system toward the convergence to diagonal form. We conclude with a wider overview.

  5. Physical and numerical aspects of the high-speed unsteady flow around concave axisymmetric bodies

    NASA Astrophysics Data System (ADS)

    Panaras, Argyris; Drikakis, Dimitris

    2011-09-01

    The axisymmetric concave body is a typical configuration about which shock/shock interactions appear. Various shapes of axisymmetric concave bodies are used in a variety of applications in aeronautics, for example, axisymmetric jet inlets with conical centerbody, ballistic missiles drag reduction by spike, plasma or hot gas injection, parachutes for pilot-ejection capsules. However, it is well known that two distinct modes of instability appear around a concave body in the high-speed flow regime for a certain range of geometric parameters. These instabilities can cause undesirable effects such as severe vibration of the structure, heating and pressure loads. According to the experimental evidence, the unsteady flow is characterised by periodic radial inflation and collapse of the conical separation bubble formed around the forebody (pulsation). Various explanations have been given for the driving mechanism of the instabilities. In the present, merging of the leading explanations is done, and basic rules for the passive suppression of the instabilities are applied, in order to enforce their proposed driving. In addition, the effect of the flow initialisation method on the flow structure predicted by numerical simulations is examined. For certain configurations, bifurcation of the time-dependent flow has been found. This behaviour is explained with recourse to the phenomenon of hysteresis, which is an inherent feature of the examined flows.

  6. Factors affecting numerical typing performance of young adults in a hear-and-type task.

    PubMed

    Lin, Cheng-Jhe; Wu, Changxu

    2011-12-01

    Numerical hear-and-type tasks, i.e. making immediate keypresses according to verbally presented numbers, possess both practical and theoretical importance but received relatively little attention. Effects of speech rates (500-ms vs. 1000-ms interval), urgency (urgent condition: performance-based monetary incentive plus time limit vs. non-urgent condition: flat-rate compensation) and finger strategies (single vs. multi-finger typing) on typing speed and accuracy were investigated. Fast speech rate and multi-finger typing produced more errors and slower typing speed. Urgency improved typing speed but decreased accuracy. Errors were almost doubled under urgent condition, while urgency effect on speed was similar to that of speech rate. Examination of error patterns did not fully support Salthouse's (1986) speculations about error-making mechanisms. The results implied that urgency could play a more important role in error-making than task demands. Numerical keyboard design and error detection could benefit from spatial incidence of errors found in this study. STATEMENT OF RELEVANCE: This study revealed that classic speculations about error-making mechanisms in alphabetical typing do not necessarily translate to numerical typing. Factors other than external task demands such as urgency can affect typing performance to a similar or greater extent. Investigations of intrinsic error-making factors in non-traditional typing tasks are encouraged.

  7. Percolation in sign-symmetric random fields: topological aspects and numerical modeling

    PubMed

    Milovanov; Zimbardo

    2000-07-01

    The topology of percolation in random scalar fields psi(x) with sign symmetry [i.e., that the statistical properties of the functions psi(x) and -psi(x) are identical] is analyzed. Based on methods of general topology, we show that the zero set psi(x)=0 of the n-dimensional (n>/=2) sign-symmetric random field psi(x) contains a (connected) percolating subset under the condition |nablapsi(x)| not equal0 everywhere except in domains of negligible measure. The fractal geometry of percolation is analyzed in more detail in the particular case of the two-dimensional (n=2) fields psi(x). The improved Alexander-Orbach conjecture [Phys. Rev. E 56, 2437 (1997)] is applied analytically to obtain estimates of the main fractal characteristics of the percolating fractal sets generated by the horizontal "cuts," psi(x)=h, of the field psi(x). These characteristics are the Hausdorff fractal dimension of the set, D, and the index of connectivity, straight theta. We advocate an unconventional approach to studying the geometric properties of fractals, which involves methods of homotopic topology. It is shown that the index of connectivity, straight theta, of a fractal set is the topological invariant of this set, i.e., it remains unchanged under the homeomorphic deformations of the fractal. This issue is explicitly used in our study to find the Hausdorff fractal dimension of the single isolevels of the field psi(x), as well as the related geometric quantities. The results obtained are analyzed numerically in the particular case when the random field psi(x) is given by a fractional Brownian surface whose topological properties recover well the main assumptions of our consideration.

  8. Lagrangian methods for blood damage estimation in cardiovascular devices--How numerical implementation affects the results.

    PubMed

    Marom, Gil; Bluestein, Danny

    2016-01-01

    This paper evaluated the influence of various numerical implementation assumptions on predicting blood damage in cardiovascular devices using Lagrangian methods with Eulerian computational fluid dynamics. The implementation assumptions that were tested included various seeding patterns, stochastic walk model, and simplified trajectory calculations with pathlines. Post processing implementation options that were evaluated included single passage and repeated passages stress accumulation and time averaging. This study demonstrated that the implementation assumptions can significantly affect the resulting stress accumulation, i.e., the blood damage model predictions. Careful considerations should be taken in the use of Lagrangian models. Ultimately, the appropriate assumptions should be considered based the physics of the specific case and sensitivity analysis, similar to the ones presented here, should be employed.

  9. Lagrangian methods for blood damage estimation in cardiovascular devices - How numerical implementation affects the results

    PubMed Central

    Marom, Gil; Bluestein, Danny

    2016-01-01

    Summary This paper evaluated the influence of various numerical implementation assumptions on predicting blood damage in cardiovascular devices using Lagrangian methods with Eulerian computational fluid dynamics. The implementation assumptions that were tested included various seeding patterns, stochastic walk model, and simplified trajectory calculations with pathlines. Post processing implementation options that were evaluated included single passage and repeated passages stress accumulation and time averaging. This study demonstrated that the implementation assumptions can significantly affect the resulting stress accumulation, i.e., the blood damage model predictions. Careful considerations should be taken in the use of Lagrangian models. Ultimately, the appropriate assumptions should be considered based the physics of the specific case and sensitivity analysis, similar to the ones presented here, should be employed. PMID:26679833

  10. ALE meta-analysis reveals dissociable networks for affective and discriminative aspects of touch.

    PubMed

    Morrison, India

    2016-04-01

    Emotionally-laden tactile stimulation-such as a caress on the skin or the feel of velvet-may represent a functionally distinct domain of touch, underpinned by specific cortical pathways. In order to determine whether, and to what extent, cortical functional neuroanatomy supports a distinction between affective and discriminative touch, an activation likelihood estimate (ALE) meta-analysis was performed. This meta-analysis statistically mapped reported functional magnetic resonance imaging (fMRI) activations from 17 published affective touch studies in which tactile stimulation was associated with positive subjective evaluation (n = 291, 34 experimental contrasts). A separate ALE meta-analysis mapped regions most likely to be activated by tactile stimulation during detection and discrimination tasks (n = 1,075, 91 experimental contrasts). These meta-analyses revealed dissociable regions for affective and discriminative touch, with posterior insula (PI) more likely to be activated for affective touch, and primary somatosensory cortices (SI) more likely to be activated for discriminative touch. Secondary somatosensory cortex had a high likelihood of engagement by both affective and discriminative touch. Further, meta-analytic connectivity (MCAM) analyses investigated network-level co-activation likelihoods independent of task or stimulus, across a range of domains and paradigms. Affective-related PI and discriminative-related SI regions co-activated with different networks, implicated in dissociable functions, but sharing somatosensory co-activations. Taken together, these meta-analytic findings suggest that affective and discriminative touch are dissociable both on the regional and network levels. However, their degree of shared activation likelihood in somatosensory cortices indicates that this dissociation reflects functional biases within tactile processing networks, rather than functionally and anatomically distinct pathways.

  11. Psychological Aspects in Children Affected by Duchenne De Boulogne Muscular Dystrophy

    PubMed Central

    Parisi, Lucia; Roccella, Michele

    2014-01-01

    Impairment of intelligence in Duchenne muscular dystrophy (DMD) patients was described by Duchenne de Boulogne himself in 1868. Further studies report intelligence disorders with mayor impairment of memory. The aim of the present study was to assess the presence of affective and personality disorders in a group of children affected by DMD. Twenty six male DMD patients, mean age eleven and four months years old, were assessed for their affective and personality disorder. Only eight subjects had a total IQ below average with major difficulties in verbal and visual-spatial memory, comprehension, arithmetic and vocabulary. All the subjects presented some disorders: tendency to marginalization and isolation, self-depreciation, sense of insecurity, hypochondriac thoughts and marked state of anxiety. These disorders are often a dynamic prolongation of a psychological process which starts when the diagnosis is made and continues, in a slow and latent fashion, throughout the evolution of the disease. PMID:25478112

  12. ALE meta‐analysis reveals dissociable networks for affective and discriminative aspects of touch

    PubMed Central

    2016-01-01

    Abstract Emotionally‐laden tactile stimulation—such as a caress on the skin or the feel of velvet—may represent a functionally distinct domain of touch, underpinned by specific cortical pathways. In order to determine whether, and to what extent, cortical functional neuroanatomy supports a distinction between affective and discriminative touch, an activation likelihood estimate (ALE) meta‐analysis was performed. This meta‐analysis statistically mapped reported functional magnetic resonance imaging (fMRI) activations from 17 published affective touch studies in which tactile stimulation was associated with positive subjective evaluation (n = 291, 34 experimental contrasts). A separate ALE meta‐analysis mapped regions most likely to be activated by tactile stimulation during detection and discrimination tasks (n = 1,075, 91 experimental contrasts). These meta‐analyses revealed dissociable regions for affective and discriminative touch, with posterior insula (PI) more likely to be activated for affective touch, and primary somatosensory cortices (SI) more likely to be activated for discriminative touch. Secondary somatosensory cortex had a high likelihood of engagement by both affective and discriminative touch. Further, meta‐analytic connectivity (MCAM) analyses investigated network‐level co‐activation likelihoods independent of task or stimulus, across a range of domains and paradigms. Affective‐related PI and discriminative‐related SI regions co‐activated with different networks, implicated in dissociable functions, but sharing somatosensory co‐activations. Taken together, these meta‐analytic findings suggest that affective and discriminative touch are dissociable both on the regional and network levels. However, their degree of shared activation likelihood in somatosensory cortices indicates that this dissociation reflects functional biases within tactile processing networks, rather than functionally and anatomically distinct

  13. Slope aspect affects geomorphic dynamics of coal mining spoil heaps in Belgium

    NASA Astrophysics Data System (ADS)

    Nyssen, Jan; Vermeersch, Dominiek

    2010-11-01

    After the abandonment of coal mining in Belgium in the 1960s-1980s, many coal tips have been left to themselves. Increasingly, these coal tips are regarded as socio-cultural heritage and protected for their environmental value. This research analyses the spatial distribution of the main geomorphic processes (sheet and rill erosion, landsliding, rock fragment movement and root throw) occurring on coal tips in Belgium, through mapping of the processes and their causal factors. Five spoil heaps spread over the major coal basins were studied in detail. The spoil heaps were subdivided in homogeneous land units, especially with regard to slope gradient, vegetation cover and slope aspect. Qualitative and quantitative observations were done on processes and potential causal factors. Regressions showed that generally, the expression of slope processes on the studied coal tips is (1) strongly dependent on westerly aspect of the slopes, (2) independent of slope gradient (which presents a narrow range), (3) impeded by grass cover, and (4) not fully predictable due to variability in type and age of dumped mine spoil.

  14. Do increases in selected fitness parameters affect the aesthetic aspects of classical ballet performance?

    PubMed

    Twitchett, Emily A; Angioi, Manuela; Koutedakis, Yiannis; Wyon, Matthew

    2011-03-01

    Research has indicated that classical ballet dancers tend to have lower fitness levels and increased injury rates compared to other athletes with similar workloads. The aim of the current study was to examine the effects of a specifically tailored fitness training programme on the incidence of injury and the aesthetic quality of performance of classical ballet dancers compared to a control group. Proficiency in performance was evaluated at the beginning and end of the intervention period for both groups through a 4-min dance sequence using previously ratified marking criteria. The intervention group (n = 8) partook in a weekly 1-hr training session that included aerobic interval training, circuit training, and whole body vibration. All dancers' performance proficiency scores increased from pre-intervention testing to post-intervention. The intervention group's overall performance scores demonstrated a significantly greater increase (p = 0.03) than the equivalent for the control group. It was concluded that supplementary fitness training has a positive effect on aspects related to aesthetic dance performance as studied herein; further research is recommended on a larger and more varied sample. Practical applications from this study suggest that supplemental training should be part of a ballet dancer's regime, and minimal intervention time is required to have observable effects.

  15. EC treatment for reuse of tissue paper wastewater: aspects that affect energy consumption.

    PubMed

    Terrazas, Eduardo; Vázquez, Armando; Briones, Roberto; Lázaro, Isabel; Rodríguez, Israel

    2010-09-15

    The need for more rational use of water also calls for more efficient usage. An example is the production of tissue paper, where large amounts of water are discharged into the drain because its turbidity does not allow for recirculation. While this is a serious problem, even worse is the fact that the quality of such wastewater makes it difficult not only to recirculate but also to discharge due to environmental law restrictions. In this paper, electrocoagulation is proposed as a suitable technology to meet standards of water discharge, and even better, as a treatment option for removal of turbidity. Since energy consumption has been a drawback for EC applications, relevant aspects that contribute to increase it such as cell voltage and current density have been reviewed. For this purpose a systematic micro-electrolysis study combined with macro-electrolysis experiments have provided evidence that shows it is possible to achieve a turbidity removal of 92% with an energy consumption of 0.68 kWh/m(3). Thus, the results presented in this paper support the use of EC to obtain water of acceptable quality for reuse in the tissue paper industry.

  16. Long-range forces affecting equilibrium inertial focusing behavior in straight high aspect ratio microfluidic channels

    NASA Astrophysics Data System (ADS)

    Reece, Amy E.; Oakey, John

    2016-04-01

    The controlled and directed focusing of particles within flowing fluids is a problem of fundamental and technological significance. Microfluidic inertial focusing provides passive and precise lateral and longitudinal alignment of small particles without the need for external actuation or sheath fluid. The benefits of inertial focusing have quickly enabled the development of miniaturized flow cytometers, size-selective sorting devices, and other high-throughput particle screening tools. Straight channel inertial focusing device design requires knowledge of fluid properties and particle-channel size ratio. Equilibrium behavior of inertially focused particles has been extensively characterized and the constitutive phenomena described by scaling relationships for straight channels of square and rectangular cross section. In concentrated particle suspensions, however, long-range hydrodynamic repulsions give rise to complex particle ordering that, while interesting and potentially useful, can also dramatically diminish the technique's effectiveness for high-throughput particle handling applications. We have empirically investigated particle focusing behavior within channels of increasing aspect ratio and have identified three scaling regimes that produce varying degrees of geometrical ordering between focused particles. To explore the limits of inertial particle focusing and identify the origins of these long-range interparticle forces, we have explored equilibrium focusing behavior as a function of channel geometry and particle concentration. Experimental results for highly concentrated particle solutions identify equilibrium thresholds for focusing that scale weakly with concentration and strongly with channel geometry. Balancing geometry mediated inertial forces with estimates for interparticle repulsive forces now provide a complete picture of pattern formation among concentrated inertially focused particles and enhance our understanding of the fundamental limits of

  17. Long-range forces affecting equilibrium inertial focusing behavior in straight high aspect ratio microfluidic channels.

    PubMed

    Reece, Amy E; Oakey, John

    2016-04-01

    The controlled and directed focusing of particles within flowing fluids is a problem of fundamental and technological significance. Microfluidic inertial focusing provides passive and precise lateral and longitudinal alignment of small particles without the need for external actuation or sheath fluid. The benefits of inertial focusing have quickly enabled the development of miniaturized flow cytometers, size-selective sorting devices, and other high-throughput particle screening tools. Straight channel inertial focusing device design requires knowledge of fluid properties and particle-channel size ratio. Equilibrium behavior of inertially focused particles has been extensively characterized and the constitutive phenomena described by scaling relationships for straight channels of square and rectangular cross section. In concentrated particle suspensions, however, long-range hydrodynamic repulsions give rise to complex particle ordering that, while interesting and potentially useful, can also dramatically diminish the technique's effectiveness for high-throughput particle handling applications. We have empirically investigated particle focusing behavior within channels of increasing aspect ratio and have identified three scaling regimes that produce varying degrees of geometrical ordering between focused particles. To explore the limits of inertial particle focusing and identify the origins of these long-range interparticle forces, we have explored equilibrium focusing behavior as a function of channel geometry and particle concentration. Experimental results for highly concentrated particle solutions identify equilibrium thresholds for focusing that scale weakly with concentration and strongly with channel geometry. Balancing geometry mediated inertial forces with estimates for interparticle repulsive forces now provide a complete picture of pattern formation among concentrated inertially focused particles and enhance our understanding of the fundamental limits of

  18. Warning: subtle aspects of strategy assessment may affect correlations among spatial tests.

    PubMed

    Glück, Judith; Dünser, Andreas; Steinbügl, Karin; Kaufmann, Hannes

    2007-02-01

    In this study, preliminary to a larger experiment, 42 participants completed four different spatial tests and, after each test, a strategy questionnaire. For half of the participants, visualizational strategies were presented first in this questionnaire, and for the other half, analytical strategies. The order of strategy descriptions had effects on the strategies reported and on the intercorrelations among the spatial tests and between the spatial tests and an inductive-reasoning test. In the group first presented with visualizational strategies, intercorrelations among the spatial tests were higher and correlations with the reasoning test were lower than in the group first presented with analytical strategies. Bootstrap analyses with 100 random splits of the sample confirmed this result. The findings are interpreted as indications of a priming effect by the strategy descriptions which affected the way participants dealt with subsequent tests. Implications for strategy assessment are discussed.

  19. Quality and safety aspects of meat products as affected by various physical manipulations of packaging materials.

    PubMed

    Lee, Keun Taik

    2010-09-01

    This article explores the effects of physically manipulated packaging materials on the quality and safety of meat products. Recently, innovative measures for improving quality and extending the shelf-life of packaged meat products have been developed, utilizing technologies including barrier film, active packaging, nanotechnology, microperforation, irradiation, plasma and far-infrared ray (FIR) treatments. Despite these developments, each technology has peculiar drawbacks which will need to be addressed by meat scientists in the future. To develop successful meat packaging systems, key product characteristics affecting stability, environmental conditions during storage until consumption, and consumers' packaging expectations must all be taken into consideration. Furthermore, the safety issues related to packaging materials must also be taken into account when processing, packaging and storing meat products.

  20. Numerical investigation of non-Newtonian fluids in annular ducts with finite aspect ratio using lattice Boltzmann method.

    PubMed

    Khali, S; Nebbali, R; Ameziani, D E; Bouhadef, K

    2013-05-01

    In this work the instability of the Taylor-Couette flow for Newtonian and non-Newtonian fluids (dilatant and pseudoplastic fluids) is investigated for cases of finite aspect ratios. The study is conducted numerically using the lattice Boltzmann method (LBM). In many industrial applications, the apparatuses and installations drift away from the idealized case of an annulus of infinite length, and thus the end caps effect can no longer be ignored. The inner cylinder is rotating while the outer one and the end walls are maintained at rest. The lattice two-dimensional nine-velocity (D2Q9) Boltzmann model developed from the Bhatnagar-Gross-Krook approximation is used to obtain the flow field for fluids obeying the power-law model. The combined effects of the Reynolds number, the radius ratio, and the power-law index n on the flow characteristics are analyzed for an annular space of finite aspect ratio. Two flow modes are obtained: a primary Couette flow (CF) mode and a secondary Taylor vortex flow (TVF) mode. The flow structures so obtained are different from one mode to another. The critical Reynolds number Re(c) for the passage from the primary to the secondary mode exhibits the lowest value for the pseudoplastic fluids and the highest value for the dilatant fluids. The findings are useful for studies of the swirling flow of non-Newtonians fluids in axisymmetric geometries using LBM. The flow changes from the CF to TVF and its structure switches from the two-cells to four-cells regime for both Newtonian and dilatant fluids. Contrariwise for pseudoplastic fluids, the flow exhibits 2-4-2 structure passing from two-cells to four cells and switches again to the two-cells configuration. Furthermore, the critical Reynolds number presents a monotonic increase with the power-law index n of the non-Newtonian fluid, and as the radius ratio grows, the transition flow regimes tend to appear for higher critical Reynolds numbers.

  1. The impact of cognitive and affective aspects of cognitive conflict on learners' conceptual change about floating and sinking

    NASA Astrophysics Data System (ADS)

    Hadjiachilleos, Stella; Valanides, Nicos; Angeli, Charoula

    2013-07-01

    Background: Cognitive conflict has been identified as an important factor for bringing about students' conceptual change. Researchers draw attention to the need to study not only cognitive factors related to cognitive conflict but affective factors as well. Purpose: The purpose of this study was to investigate the contribution of cognitive and non-cognitive aspects involved in cognitive conflict on students' conceptual change. Sample: Fifteen students, five from each of fourth, sixth and eighth grades, participated in the study. Seven students were male, and the rest were female. All students had high academic performance and were good at explaining their reasoning. Design and method: The study focused on gaining in-depth information, using semi-structured clinical interviews, about students' thinking when they were engaged in an inquiry process, which incorporated cognitive conflict using a scenario about floating and sinking. Students' initial conceptions related to the phenomenon of floating and sinking were first diagnosed and, subsequently, discrepant events were presented to challenge their initial conceptions. The 15 interviews were qualitatively analyzed using the constant comparative analysis method. Results: The results of this study showed that students' conceptual change was directly related to both cognitive and affective aspects of cognitive conflict. The results also showed that some students showed persistence on alternative frameworks even after their exposure to cognitive conflict. Conclusions: Cognitive conflict is an idiosyncratic, or personal event, that may not be experienced by all learners in the same way. Thus, the effect of cognitive conflict on learners' conceptual change is directly related to learners' ability to experience and feel the conflict when it is presented to them.

  2. Numerical simulation of friction stir welding (FSW): Prediction of the heat affect zone using a softening model

    NASA Astrophysics Data System (ADS)

    Paulo, R. M. F.; Carlone, P.; Valente, R. A. F.; Teixeira-Dias, F.; Palazzo, G. S.

    2016-10-01

    In this work a numerical model is proposed to simulate Friction Stir Welding (FSW) process in AA2024-T3 plates. This model included a softening model that account for the temperature history and the hardness distribution on a welded plate can thus be predicted. The validation of the model was performed using experimental measurements of the hardness in the plate cross-section. There is an acceptable prediction of the material softening in the Heat Affected Zone (HAZ) using the adopted model.

  3. Passive solar in Milton Keynes, England. A description of some of the more numerical aspects of the design of an estate of low energy houses

    NASA Astrophysics Data System (ADS)

    Everett, R.

    1980-07-01

    The numerical aspects of the design of low energy consumption houses using passive solar energy collection and high levels of insulation are described. Two housing energy conservation projects were begun, one involving the construction of 177 low energy houses on a cost-effective basis, and the other involving the detailed monitoring of eight highly insulated passive solar houses. Both experimental data and theoretical analysis are presented, and the relative effectiveness of the various design alternatives are discussed.

  4. Chamber QoE: a multi-instrumental approach to explore affective aspects in relation to quality of experience

    NASA Astrophysics Data System (ADS)

    De Moor, Katrien; Mazza, Filippo; Hupont, Isabelle; Ríos Quintero, Miguel; Mäki, Toni; Varela, Martín.

    2014-02-01

    Evaluating (audio)visual quality and Quality of Experience (QoE) from the user's perspective, has become a key element in optimizing users' experiences and their quality. Traditionally, the focus lies on how multi-level quality features are perceived by a human user. The interest has however gradually expanded towards human cognitive, affective and behavioral processes that may impact on, be an element of, or be influenced by QoE, and which have been underinvestigated so far. In addition, there is a major discrepancy between the new, broadly supported and more holistic conceptualization of QoE proposed by Le Callet et al. (2012) and traditional, standardized QoE assessment. This paper explores ways to tackle this discrepancy by means of a multi-instrumental approach. More concretely, it presents results from a lab study on video quality (N=27), aimed at going beyond the dominant QoE assessment paradigm and at exploring affective aspects in relation to QoE and in relation to perceived overall quality. Four types of data were collected: `traditional' QoE self-report measures were complemented with `alternative', emotional state- and user engagement-related self-report measures to evaluate QoE. In addition, we collected EEG (physiological) data, gazetracking data and facial expressions (behavioral) data. The video samples used in test were longer in duration than is common in standard tests allowing us to study e.g. more realistic experience and deeper user engagement. Our findings support the claim that the traditional QoE measures need to be reconsidered and extended with additional, affective staterelated measures.

  5. Numerical Investigation of Blade Lean and Sweep affecting Secondary Flows in an Axial Expansion Turbine

    NASA Astrophysics Data System (ADS)

    Neipp, A.; Riedelbauch, S.

    2016-11-01

    Based on an axial expansion turbine used for energy recovery from working fluids an automated CFD-flow optimization was performed to increase the turbine efficiency without narrowing the operating range. The optimization results showed that even small changes in the optimization target had a significant influence on the lean and sweep of the new blade designs. The resulting blade shapes were extraordinary. The lean and sweep resembled more that of thermal turbomachinery than hydraulic machinery. It became clear that the special blade shapes were a result of the very low aspect ratio of the turbine and the resulting large influence of secondary flows. The blade lean and sweep induce secondary flow structures which are of decisive importance for the turbine performance. The simulation results showed that positive compound lean increases the efficiency and positive compound sweep improves the cavitation behavior of the investigated axial expansion turbine. However the complexity of the occurring secondary flows make an universally valid statement on the effect of blade lean and sweep on the flow behavior of an axial turbine impossible.

  6. Plaque components affect wall stress in stented human carotid artery: A numerical study

    NASA Astrophysics Data System (ADS)

    Fan, Zhen-Min; Liu, Xiao; Du, Cheng-Fei; Sun, An-Qiang; Zhang, Nan; Fan, Zhan-Ming; Fan, Yu-Bo; Deng, Xiao-Yan

    2016-12-01

    Carotid artery stenting presents challenges of in-stent restenosis and late thrombosis, which are caused primarily by alterations in the mechanical environment of the artery after stent implantation. The present study constructed patient-specific carotid arterial bifurcation models with lipid pools and calcified components based on magnetic resonance imaging. We numerically analyzed the effects of multicomponent plaques on the distributions of von Mises stresses (VMSs) in the patient-specific models after stenting. The results showed that when a stent was deployed, the large soft lipid pool in atherosclerotic plaques cushioned the host artery and reduced the stress within the arterial wall; however, this resulted in a sharp increase of VMS in the fibrous cap. When compared with the lipid pool, the presence of the calcified components led to slightly increased stresses on the luminal surface. However, when a calcification was located close to the luminal surface of the host artery and the stenosis, the local VMS was elevated. Overall, compared with calcified components, large lipid pools severely damaged the host artery after stenting. Furthermore, damage due to the calcified component may depend on location.

  7. A direct numerical simulation of cool-flame affected autoignition in diesel engine-relevant conditions

    SciTech Connect

    Krisman, Alex; Hawkes, Evatt R.; Talei, Mohsen; Bhagatwala, Ankit; Chen, Jacqueline H.

    2016-11-11

    In diesel engines, combustion is initiated by a two-staged autoignition that includes both low- and high-temperature chemistry. The location and timing of both stages of autoignition are important parameters that influence the development and stabilisation of the flame. In this study, a two-dimensional direct numerical simulation (DNS) is conducted to provide a fully resolved description of ignition at diesel engine-relevant conditions. The DNS is performed at a pressure of 40 atmospheres and at an ambient temperature of 900 K using dimethyl ether (DME) as the fuel, with a 30 species reduced chemical mechanism. At these conditions, similar to diesel fuel, DME exhibits two-stage ignition. The focus of this study is on the behaviour of the low-temperature chemistry (LTC) and the way in which it influences the high-temperature ignition. The results show that the LTC develops as a “spotty” first-stage autoignition in lean regions which transitions to a diffusively supported cool-flame and then propagates up the local mixture fraction gradient towards richer regions. The cool-flame speed is much faster than can be attributed to spatial gradients in first-stage ignition delay time in homogeneous reactors. The cool-flame causes a shortening of the second-stage ignition delay times compared to a homogeneous reactor and the shortening becomes more pronounced at richer mixtures. Multiple high-temperature ignition kernels are observed over a range of rich mixtures that are much richer than the homogeneous most reactive mixture and most kernels form much earlier than suggested by the homogeneous ignition delay time of the corresponding local mixture. Altogether, the results suggest that LTC can strongly influence both the timing and location in composition space of the high-temperature ignition.

  8. A direct numerical simulation of cool-flame affected autoignition in diesel engine-relevant conditions

    DOE PAGES

    Krisman, Alex; Hawkes, Evatt R.; Talei, Mohsen; ...

    2016-11-11

    In diesel engines, combustion is initiated by a two-staged autoignition that includes both low- and high-temperature chemistry. The location and timing of both stages of autoignition are important parameters that influence the development and stabilisation of the flame. In this study, a two-dimensional direct numerical simulation (DNS) is conducted to provide a fully resolved description of ignition at diesel engine-relevant conditions. The DNS is performed at a pressure of 40 atmospheres and at an ambient temperature of 900 K using dimethyl ether (DME) as the fuel, with a 30 species reduced chemical mechanism. At these conditions, similar to diesel fuel,more » DME exhibits two-stage ignition. The focus of this study is on the behaviour of the low-temperature chemistry (LTC) and the way in which it influences the high-temperature ignition. The results show that the LTC develops as a “spotty” first-stage autoignition in lean regions which transitions to a diffusively supported cool-flame and then propagates up the local mixture fraction gradient towards richer regions. The cool-flame speed is much faster than can be attributed to spatial gradients in first-stage ignition delay time in homogeneous reactors. The cool-flame causes a shortening of the second-stage ignition delay times compared to a homogeneous reactor and the shortening becomes more pronounced at richer mixtures. Multiple high-temperature ignition kernels are observed over a range of rich mixtures that are much richer than the homogeneous most reactive mixture and most kernels form much earlier than suggested by the homogeneous ignition delay time of the corresponding local mixture. Altogether, the results suggest that LTC can strongly influence both the timing and location in composition space of the high-temperature ignition.« less

  9. [Assessing various aspects of the motivation to eat that can affect food intake and body weight control].

    PubMed

    Bellisle, F

    2009-04-01

    Over the last 30 years, several questionnaires have been developed and validated in order to assess many aspects of the motivation to eat that might be susceptible to impair adequate food intake and body weight control. A few of such questionnaires are described here, in particular, the "Three Factor Eating Questionnaire" also called the "Eating Inventory", and the "Dutch Eating Behavior Questionnaire". Critical aspects of the motivation to eat assessed by these tools are presented, such as dietary restraint, disinhibition, hunger, vulnerability to eat in response to external cues or emotional states, etc. These questionnaires were developed for use in the general population with the aim to identify critical aspects of the motivation to eat that might predispose to weight gain. They have been widely used in many countries and have allowed an improved understanding of the individual characteristics that predispose to body weight gain or resistance to weight loss. Originally, poor body weight control was attributed to a high level of dietary "restraint", or in other words, the tendency to deliberately restrict one's food intake for body weight control purposes. Such dietary restraint was suspected to lead to a number of physical and psychological difficulties, among which poor self-esteem and a paradoxical tendency to gain weight, resulting from the incapacity to maintain strict restraint over time. More recent studies have established that a motivational trait called "Disinhibition" is a strong predictor of body weight gain over time and of poor outcome of dieting. "Disinhibition" corresponds to a tendency to lose control over one's eating behavior and ingest excessively large quantities of food substances, in response to a variety of cues and circumstances. In addition to its untoward effect on weight, disinhibition also predicts various risk factors and pathologies, such as hypertension and diabetes. Other potentially critical dimensions for adequate body weight

  10. Theoretical-Numerical Study of Feasibility of Use of Winglets on Low Aspect Ration Wings at Subsonic and Transonic Mach Numbers to Reduce Drag

    NASA Technical Reports Server (NTRS)

    Kuhlman, John M.; Liaw, Paul; Cerney, Michael J.

    1988-01-01

    A numerical design study was conducted to assess the drag reduction potential of winglets installed on a series of low aspect ratio wings at a design point of M=0.8, C sub L=0.3. Wing-winglet and wing-alone design geometries were obtained for wings of aspect ratios between 1.75 and 2.67, having leading edge sweep angles between 45 and 60 deg. Winglet length was fixed at 15% of wing semispan. To assess the relative performance between wing-winglet and wing-alone configurations, the PPW nonlinear extended small disturbance potential flow code was utilized. This model has proven to yield plausible transonic flow field simulations for the series of low aspect ratio configurations selected. Predicted decreases in pressure drag coefficient for the wing-winglet configurations relative to the corresponding wing-alone planform are about 15% at the design point. Predicted decreases in wing-winglet total drag coefficient are about 12%, relative to the corresponding wing-alone design. Longer winglets (25% of the wing semispan) yielded decreases in the pressure drag of up to 22% and total drag of up to 16.4%. These predicted drag coefficient reductions are comparable to reductions already demonstrated by actual winglet designs installed on higher aspect ratio transport type aircraft.

  11. Numerical design of X-ray tabletop Talbot interferometer using polycapillary optics as two-dimensional gratings with high aspect ratio

    NASA Astrophysics Data System (ADS)

    Sun, Weiyuan; Liu, Zhiguo; Sun, Tianxi; Sun, Xuepeng; Li, Fangzuo; Jiang, Bowen; Ding, Xunliang

    2015-12-01

    The polycapillary optics was proposed to be used as two-dimensional X-ray gratings with high aspect ratios for high energy X-rays. The X-ray Talbot interferometer was designed numerically using the polycapillary X-ray gratings and a conventional X-ray source. The simulation showed that it was available to get a high-aspect-ratio pattern of the polycapillary X-ray gratings for higher energies than 60 keV. Moreover, this design of polycapillary gratings decreased the requirement for high power of the X-ray source. The polycapillary X-ray gratings had potential applications in X-ray imaging technology for medical fields, industrial nondestructive tests, public security, physical science, chemical analysis, life science, nanoscience biology and energy science.

  12. Does Grammatical Aspect Affect Motion Event Cognition? A Cross-Linguistic Comparison of English and Swedish Speakers

    ERIC Educational Resources Information Center

    Athanasopoulos, Panos; Bylund, Emanuel

    2013-01-01

    In this article, we explore whether cross-linguistic differences in grammatical aspect encoding may give rise to differences in memory and cognition. We compared native speakers of two languages that encode aspect differently (English and Swedish) in four tasks that examined verbal descriptions of stimuli, online triads matching, and memory-based…

  13. Numerical assessment affects aggression and competitive ability: a team-fighting strategy for the ant Formica xerophila

    PubMed Central

    Tanner, Colby J

    2006-01-01

    The relationship between numerical advantage and competitive ability is a fundamental component in contests between groups of social animals. An individual's ability to correctly assess the numerical state of its group is of vital importance. In addition to numerical dominance, the group's fighting ability also plays an important role in competitive interactions. By staging experimental fights between two Formica ant species, I show that Formica xerophila are able to assess their own group's strength prior to any competitive encounter. Ants that perceive themselves as part of a large group act more aggressively toward a competitor than ants that perceive themselves as isolated individuals. This increase in aggression improves F. xerophila's competitive ability. Furthermore, the number of individuals in a contest was found to affect competitive ability. In contests with equal number of competitors, groups of F. xerophila were more successful than individual F. xerophila. Contrary to previous predictions using Lanchester's laws of fighting, F. xerophila's ability to kill competitors increased nonlinearly with group size. This nonlinearity was due to the collective fighting strategy of an F. xerophila group isolating and engaging a single Formica integroides competitors. PMID:17015327

  14. 3-D Numerical Simulation and Analysis of Complex Fiber Geometry RaFC Materials with High Volume Fraction and High Aspect Ratio based on ABAQUS PYTHON

    NASA Astrophysics Data System (ADS)

    Jin, BoCheng

    2011-12-01

    Organic and inorganic fiber reinforced composites with innumerable fiber orientation distributions and fiber geometries are abundantly available in several natural and synthetic structures. Inorganic glass fiber composites have been introduced to numerous applications due to their economical fabrication and tailored structural properties. Numerical characterization of such composite material systems is necessitated due to their intrinsic statistical nature, which renders extensive experimentation prohibitively time consuming and costly. To predict various mechanical behavior and characterizations of Uni-Directional Fiber Composites (UDFC) and Random Fiber Composites (RaFC), we numerically developed Representative Volume Elements (RVE) with high accuracy and efficiency and with complex fiber geometric representations encountered in uni-directional and random fiber networks. In this thesis, the numerical simulations of unidirectional RaFC fiber strand RVE models (VF>70%) are first presented by programming in ABAQUS PYTHON. Secondly, when the cross sectional aspect ratios (AR) of the second phase fiber inclusions are not necessarily one, various types of RVE models with different cross sectional shape fibers are simulated and discussed. A modified random sequential absorption algorithm is applied to enhance the volume fraction number (VF) of the RVE, which the mechanical properties represents the composite material. Thirdly, based on a Spatial Segment Shortest Distance (SSSD) algorithm, a 3-Dimentional RaFC material RVE model is simulated in ABAQUS PYTHON with randomly oriented and distributed straight fibers of high fiber aspect ratio (AR=100:1) and volume fraction (VF=31.8%). Fourthly, the piecewise multi-segments fiber geometry is obtained in MATLAB environment by a modified SSSD algorithm. Finally, numerical methods including the polynomial curve fitting and piecewise quadratic and cubic B-spline interpolation are applied to optimize the RaFC fiber geometries

  15. Numerical modelling of the physical factors that affect mass transport in the vasculature at early time periods.

    PubMed

    Denny, William J; Walsh, Michael T

    2014-03-01

    Coronary artery disease results in blockages or narrowing of the artery lumen. Drug eluting stents were developed to replace bare metal stents in an effort to combat re-blocking of the lumen. A key element in determining the therapeutic success of a drug eluting stent is an in-depth understanding of the physical factors that affect mass transport of the drug into the arterial wall, over early time periods. The numerical models developed within this study focus on assessing the influence of a host of physical factors that either facilitate or impede therapeutic drug delivery into the arterial wall from the unit cell of an idealised stent. This study demonstrates that model reduction strategies to 2D and 1D can still adequately represent a 3D curved arterial wall and strut polymer coating, respectively, using an idealistic stent geometry. It was shown that the level of strut compression can have a significant impact on therapeutic drug delivery in the arterial wall.

  16. Does fluid infiltration affect the motion of sediment grains? - A 3-D numerical modelling approach using SPH

    NASA Astrophysics Data System (ADS)

    Bartzke, Gerhard; Rogers, Benedict D.; Fourtakas, Georgios; Mokos, Athanasios; Huhn, Katrin

    2016-04-01

    The processes that cause the creation of a variety of sediment morphological features, e.g. laminated beds, ripples, or dunes, are based on the initial motion of individual sediment grains. However, with experimental techniques it is difficult to measure the flow characteristics, i.e., the velocity of the pore water flow in sediments, at a sufficient resolution and in a non-intrusive way. As a result, the role of fluid infiltration at the surface and in the interior affecting the initiation of motion of a sediment bed is not yet fully understood. Consequently, there is a strong need for numerical models, since these are capable of quantifying fluid driven sediment transport processes of complex sediment beds composed of irregular shapes. The numerical method Smoothed Particle Hydrodynamics (SPH) satisfies this need. As a meshless and Lagrangian technique, SPH is ideally suited to simulating flows in sediment beds composed of various grain shapes, but also flow around single grains at a high temporal and spatial resolution. The solver chosen is DualSPHysics (www.dual.sphysics.org) since this is validated for a range of flow conditions. For the present investigation a 3-D numerical flume model was generated using SPH with a length of 4.0 cm, a width of 0.05 cm and a height of 0.2 cm where mobile sediment particles were deposited in a recess. An experimental setup was designed to test sediment configurations composed of irregular grain shapes (grain diameter, D50=1000 μm). Each bed consisted of 3500 mobile objects. After the bed generation process, the entire domain was flooded with 18 million fluid particles. To drive the flow, an oscillating motion perpendicular to the bed was applied to the fluid, reaching a peak value of 0.3 cm/s, simulating 4 seconds of real time. The model results showed that flow speeds decreased logarithmically from the top of the domain towards the surface of the beds, indicating a fully developed boundary layer. Analysis of the fluid

  17. The Impact of Cognitive and Affective Aspects of Cognitive Conflict on Learners' Conceptual Change about Floating and Sinking

    ERIC Educational Resources Information Center

    Hadjiachilleos, Stella; Valanides, Nicos; Angeli, Charoula

    2013-01-01

    Background: Cognitive conflict has been identified as an important factor for bringing about students' conceptual change. Researchers draw attention to the need to study not only cognitive factors related to cognitive conflict but affective factors as well. Purpose: The purpose of this study was to investigate the contribution of cognitive…

  18. Numerical Development

    ERIC Educational Resources Information Center

    Siegler, Robert S.; Braithwaite, David W.

    2016-01-01

    In this review, we attempt to integrate two crucial aspects of numerical development: learning the magnitudes of individual numbers and learning arithmetic. Numerical magnitude development involves gaining increasingly precise knowledge of increasing ranges and types of numbers: from non-symbolic to small symbolic numbers, from smaller to larger…

  19. Situation of classical swine fever and the epidemiologic and ecologic aspects affecting its distribution in the American continent.

    PubMed

    Vargas Terán, Moisés; Calcagno Ferrat, Nelson; Lubroth, Juan

    2004-10-01

    Classical swine fever (CSF) is a viral transboundary animal disease that is highly contagious among domestic and wild pigs, such as boars and peccaries. Today, far from being what was classically described historically, the disease is characterized as having a varied clinical picture, and its diagnosis depends on resorting to proper sample collection and prompt dispatch to a laboratory that can employ several techniques to obtain a definitive diagnosis. Laboratory findings should be complemented with a field analysis of the occurrence of disease to have a better understanding of its epidemiology. The disease is still present in various regions and countries of Latin America and the Caribbean, thus hindering production, trade, and the livestock economy in the region. Consequently, it is among the diseases included in List A of the Office International des Epizooties (OIE). Currently, there are epidemiologic and ecologic aspects that characterize its geographical distribution in the region such as: continued trends in the demand for pork and pork products; an increase in swine investment with low production costs which are able to compete advantageously in international markets; the convention of associating CSF in the syndrome of "swine hemorrhagic diseases" owing to the historical description of its acute presentation and not to the new and more frequent subacute presentations or the diseases with which it may be confused (notably, porcine reproductive and respiratory syndrome and porcine dermopathic nephropathy syndrome, among others); dissemination of the virus through asymptomatic hosts such as piglets infected in utero; frequent lack of quality control and registration of vaccines and vaccinations; feeding of swine with contaminated food waste (swill); the common practice of smuggling animals and by-products across borders; the backyard family production system or extensive open field methods of swine rearing with minimal input in care and feeding; poor

  20. Subacute oral exposure to benzo[alpha]pyrene (B[alpha]P) increases aggressiveness and affects consummatory aspects of sexual behaviour in male mice.

    PubMed

    Bouayed, Jaouad; Desor, Frédéric; Soulimani, Rachid

    2009-09-30

    Benzo[alpha]pyrene (B[alpha]P) is a neurotoxic pollutant which is also able to affect some behaviour and cognitive function. Here we report that a subacute oral exposure to B[alpha]P increases aggressiveness and affects copulatory behaviour in male mice. Indeed, after 3 weeks of exposure to B[alpha]P at 0.02 and 0.2mg/kg, we have observed that B[alpha]P 0.02 mg/kg-treated male mice are more aggressive than control mice in resident-intruder test because a significant decrease in the latency time of the first attack and a significant increase in the number of attacks in B[alpha]P 0.02 mg/kg-treated mice were found. On the other hand, we have found that subacute exposure (4 weeks) to B[alpha]P, does not affect the appetitive aspects and sexual motivation in copulatory behaviour because the latency to the first mount between control and B[alpha]P-treated male mice was not significantly different. We have nevertheless, surprisingly found that B[alpha]P (0.02-0.2)mg/kg-treated mice have performed significantly more sexual behavioural acts including mounting, intromission latency and intromission frequency than control mice. Although these last results suggest that B[alpha]P improves the consummatory aspects of sexual behaviour, we cannot conclude that this neurotoxic pollutant has advantage of sexual function because B[alpha]P has been shown to alter the monoaminergic neurotransmitter system and causes endocrine dysregulation via toxic effect.

  1. Verbal versus Numerical Probabilities: Does Format Presentation of Probabilistic Information regarding Breast Cancer Screening Affect Women's Comprehension?

    ERIC Educational Resources Information Center

    Vahabi, Mandana

    2010-01-01

    Objective: To test whether the format in which women receive probabilistic information about breast cancer and mammography affects their comprehension. Methods: A convenience sample of 180 women received pre-assembled randomized packages containing a breast health information brochure, with probabilities presented in either verbal or numeric…

  2. Selected Aspects of Numerical Modelling of the Salt Rock Mass: The Case of the "Wieliczka" Salt Mine / Wybrane aspekty modelowania numerycznego masywu solnego na przykładzie kopalni soli "wieliczka"

    NASA Astrophysics Data System (ADS)

    D'Obyrn, Kajetan; Hydzik-Wiśniewska, Joanna

    2013-03-01

    Each excavation or excavation complex intended to be backfilled or secured requires an individual approach, and conducting a detailed geomechanical analysis which will allow the selection of the appropriate manner of securing or backfilling or liquidation, and the order of performing mining works. The numerical model of the selected chamber or group of chambers must accurately reflect the reality and have an appropriately selected calculation model. The paper presents the selected aspects of numerical modelling of the "Wieliczka" salt rock mass. There are method of selection of geotechnical and rheological parameters of salt, the geometrization of the excavations continues and selection calculation model.

  3. Numerical investigations of flow and passive pollutant exposure in high-rise deep street canyons with various street aspect ratios and viaduct settings.

    PubMed

    He, Lejian; Hang, Jian; Wang, Xuemei; Lin, Borong; Li, Xiaohui; Lan, Guangdong

    2017-04-15

    Vehicular pollutant exposure of residents and pedestrians in high-rise deep street canyons with viaducts and noise barriers requires special concerns because the ventilation capacity is weak and the literature reported inconsistent findings on flow patterns as aspect ratios (building height/street width, H/W) are larger than 2. By conducting computational fluid dynamics (CFD) simulations coupled with the intake fraction iF and the daily pollutant exposure Et, this paper investigates the impact of street aspect ratios, viaducts and noise barriers on the flow and vehicular passive pollutant exposure in full-scale street canyons (H/W=1-6, W=24m). iF represents the fraction of total emissions inhaled by a population (1ppm=10(-6)), while Et means the extent of human beings' contact with pollutants within one day. CFD methodologies of passive pollutant dispersion modeling are successfully validated by wind tunnel data in Meroney et al. (1996). As a novelty, the two-main-vortex pattern start appearing in full-scale street canyons as H/W changes from 4 to 5, however previous studies using wind-tunnel-scale models (H=6cm) reported two to five vortexes as H/W=2-5. This finding is validated by both smoke visualization in scale-model outdoor field experiments (H=1.2m, W=0.6m) and CFD simulations of Reynolds number independence. Cases with two main vortexes (H/W=5-6) experience much larger daily pollutant exposure (~10(3)-10(4)mg/m(3)/day) than those with single main vortex as H/W=1-4 (~10(1)-10(2)mg/m(3)/day). Moreover leeward-side pollutant exposures are much larger than windward-side as H/W=1-4 while oppositely as H/W=5-6. Assuming a general population density, the total iF is 485-803ppm as H/W=1, 2020-12051ppm as H/W=2-4, and 51112-794026ppm as H/W=5-6. With a single elevated pollutant source, cases with viaducts experience significantly smaller pollutant exposures than cases without viaducts. Road barriers slightly increase pollutant exposure in near-road buildings with H

  4. Does Land-Surface Heterogeneity Affect the Evolution of Hurricanes after their Landfall in the Eastern US - A Numerical Study with the Ocean-Land-Atmosphere Model (OLAM)

    NASA Astrophysics Data System (ADS)

    Avissar, R.; Walko, R. L.

    2006-12-01

    The Ocean-Land-Atmosphere Model (OLAM) has been developed to extend the capabilities of the Regional Atmospheric Modeling System (RAMS) to a global modeling framework. OLAM is a new model with regard to its dynamic core, grid configuration, memory structure, and numerical solution technique. Instead of the Boussinesq approximation used in RAMS, OLAM solves the full compressible Navier-Stokes equations in conservation form using finite-volume numerical operators that conserve mass, momentum, and energy to machine precision. In place of RAMS' structured multiple nested grids and hexahedral grid cells on a polar stereographic projection, OLAM uses a single unstructured grid and pentahedral (prism) grid cells (with a triangular footprint) which conform to the sphere without a coordinate transformation. OLAM's grid topology enables local mesh refinement to any degree without the need for special grid nesting algorithms; all communication between regions of different resolution is accomplished seamlessly by flux-conservative advective and diffusive transport. OLAM represents topography using a form of the volume-fraction or shaved grid cell method in which model levels are strictly horizontal, rather than terrain-following, and therefore intersect topography. Grid cell face areas, which explicitly appear in the finite volume equations and are pre- computed and stored, are reduced in proportion to any blockage by topography, thereby correctly regulating inter-cell transport and preventing advective flux normal to the ground surface. Apart from its dynamic core and grid configuration, OLAM bears a strong resemblance to RAMS. Both models share the same physical parameterizations for microphysics, land and vegetation water and energy balances, radiative transfer, and sub-grid cumulus convection. Model coding structure, I/O file formats, and methods of compiling, initializing, and executing the models are very similar or identical. OLAM is particularly well designed to

  5. Numerical and Physical Aspects of Aerodynamic Flows

    DTIC Science & Technology

    1992-01-15

    elenmet about 20 % fewer grid points, it takes a little less comput- in this regon. ing time. The major difference between these approaches is the...8217 5 10 15’ 20 geometries in this work. Alpha OM 0.7S6 &12 - O - Fig. 2.6 Coefficient of lift versus angle of attack as computed by the overlaid grid ...55,000 points were used in the resulting composite grid in order to resolve the . 20 - flow physics adequately in the boundary layers and wakes. -15 The

  6. Separate serotonin and dopamine receptors modulate the duration of post-tetanic potentiation at an Aplysia synapse without affecting other aspects of synaptic transmission.

    PubMed

    Newlin, S A; Schlapfer, W T; Barondes, S H

    1980-01-06

    We have studied the effect of the biogenic amines, serotonin and dopamine, on post-tetanic potentiation (PTP) at an identified synapse in the abdominal ganglion of Aplysia californica. We found that: (1) 10(-7) M perfused serotonin doubles the rate constant of decay of PTP. The effect is specific in that neither the size of the non-potentiated (isolated) EPSP nor the amplitude of PTP is affected. As reported previously, higher doses of serotonin will also increase the amplitude of PTP and decrease the size of the isolated EPSP; (2) 5 X 10(-7) M dopamine in the perfusate increases the rate constant of decay of PTP by about 50%. The effect is also specific in that neither PTP amplitude nor the size of the isolated EPSP is affected; (3) SQ10,631, a serotonin antagonist, blocks the effect of perfused serotonin on PTP decay rate. It does not antagonize the dopamine effect. SQ10,631 also slows the endogenous decay of PTP in some preparations which exhibit an unusually fast PTP decay rate, suggesting a naturally occurring source of serotonin within the ganglion capable of affecting the rate constant of PTP decay; (4) (+)-butaclamol, a dopamine antagonist, blocks the effect of dopamine on the rate constant of PTP decay, whereas (-)-butaclamol has little effect. Butaclamol does not block the effect of serotonin on the rate constant of PTP decay; (5) phosphodiesterase inhibitors potentiate the effect of serotonin on the rate constant of PTP decay, and cyclic AMP analogues mimic the effect of the biogenic amines, suggesting that the aminergic modulation of the rate of decay of PTP is coupled with activation of adenylate cyclase and accumulation of cyclic AMP; and (6) the evidence presented is consistent with the hypothesis that serotonin and dopamine are capable of specifically modifying the rate of change in the efficacy of transmitter release which underlies PTP. It also suggests that the two biogenic amines operate separately and in parallel via presynaptic receptor

  7. Subduction modelling with ASPECT

    NASA Astrophysics Data System (ADS)

    Glerum, Anne; Thieulot, Cédric; Spakman, Wim; Quinquis, Matthieu; Buiter, Susanne

    2013-04-01

    ASPECT (Advanced Solver for Problems in Earth's ConvecTion) is a promising new code designed for modelling thermal convection in the mantle (Kronbichler et al. 2012). The code uses state-of-the-art numerical methods, such as high performance solvers and adaptive mesh refinement. It builds on tried-and-well-tested libraries and works with plug-ins allowing easy extension to fine-tune it to the user's specific needs. We make use of the promising features of ASPECT, especially Adaptive Mesh Refinement (AMR), for modelling lithosphere subduction in 2D and 3D geometries. The AMR allows for mesh refinement where needed and mesh coarsening in regions less important to the parameters under investigation. In the context of subduction, this amounts to having very small grid cells at material interfaces and larger cells in more uniform mantle regions. As lithosphere subduction modelling is not standard to ASPECT, we explore the necessary adaptive grid refinement and test ASPECT with widely accepted benchmarks. We showcase examples of mechanical and thermo-mechanical oceanic subduction in which we vary the number of materials making up the overriding and subducting plates as well as the rheology (from linear viscous to more complicated rheologies). Both 2D and 3D geometries are used, as ASPECT easily extends to three dimensions (Kronbichler et al. 2012). Based on these models, we discuss the advection of compositional fields coupled to material properties and the ability of AMR to trace the slab's path through the mantle. Kronbichler, M., T. Heister and W. Bangerth (2012), High Accuracy Mantle Convection Simulation through Modern Numerical Methods, Geophysical Journal International, 191, 12-29.

  8. Experimental and numerical investigation of the residual yield strength of aluminium alloy EN AW-2024-T3 affected by artificially produced pitting corrosion

    NASA Astrophysics Data System (ADS)

    Pippig, R.; Schmidl, E.; Steinert, P.; Schubert, A.; Lampke, T.

    2017-03-01

    In this study, the behaviour of the residual yield strength of aluminium alloy EN AW-2024-T3 affected by the morphology and numbers of corrosion pits (defects) is presented. Since specific defect structures are not reproducible during experimental corrosion tests, metal sheets with different numbers of pits and pit shapes are produced using laser micro structuring. The defect structures are measured using laser scanning microscopy. To compare the stress states of the micro structured and real corroded metal sheets, FE-analysis is used. Afterwards, uniaxial tensile tests are carried out and critical defect parameters in terms of yield strength reduction of the investigated aluminium alloy are detected.

  9. ROBOTIC SURGERY: BIOETHICAL ASPECTS

    PubMed Central

    SIQUEIRA-BATISTA, Rodrigo; SOUZA, Camila Ribeiro; MAIA, Polyana Mendes; SIQUEIRA, Sávio Lana

    2016-01-01

    ABSTRACT Introduction: The use of robots in surgery has been increasingly common today, allowing the emergence of numerous bioethical issues in this area. Objective: To present review of the ethical aspects of robot use in surgery. Method: Search in Pubmed, SciELO and Lilacs crossing the headings "bioethics", "surgery", "ethics", "laparoscopy" and "robotic". Results: Of the citations obtained, were selected 17 articles, which were used for the preparation of the article. It contains brief presentation on robotics, its inclusion in health and bioethical aspects, and the use of robots in surgery. Conclusion: Robotic surgery is a reality today in many hospitals, which makes essential bioethical reflection on the relationship between health professionals, automata and patients. PMID:28076489

  10. How does gully recharge affect sediment transfers by debris flows? A numerical modelling study in steep mountainous terrain, coastal British Columbia

    NASA Astrophysics Data System (ADS)

    Martin, Y. E.; Johnson, E. A.; Chaikina, O.

    2014-12-01

    Debris flows are a major process responsible for transferring sediment from high mountain locations to more downstream fluvial reaches. This sediment transfer begins on mountain hillslopes where various mass wasting processes move sediment from hillslopes to uppermost reaches of the channel system (these reaches are herein referred to as gullies and only experience water flow during high intensity precipitation events). Sediment recharge into gullies, which has received minimal attention in the scientific literature, refers to the transfer of sediment and other debris from surrounding hillslopes into gullies (Jakob and Oden, 2005). Debris flow occurrence and debris flow volumes depend on some precipitation threshold as well as volumes of material contained in the particular gully. For example, if one debris flow has removed all of the accumulated material from the gully, then any subsequent debris flow will be smaller if enough time has not yet passed for notable sediment recharge. Herein, we utilize the numerical model of landscape development, LandMod (Martin, 1998; Dadson and Church, 2005; Martin, 2007), to explore connections between hillslope processes, gully recharge rates, and transfer of sediment to downstream channel reaches in the Haida Gwaii, British Columbia. Hillslope processes in the model include shallow landsliding, bedrock failures and weathering. The updated debris flow algorithm is based on extensive field data available for debris flows in Haida Gwaii (e.g., Rood, 1984; Oden, 1994; Jakob and Oden, 2005), as well as theoretical considerations based on debris flow studies. The most significant model extension is the calculation of gully recharge rates; for each gully, the total accumulated sediment in gullies at each time step is determined using a power-law relation for area-normalized recharge rate versus elapsed time since the last debris flow. Thus, when the stochastic driver for debris flow occurrence triggers an event, the amount of stored

  11. Regulatory aspects

    NASA Astrophysics Data System (ADS)

    Stern, Arthur M.

    1986-07-01

    At this time, there is no US legislation that is specifically aimed at regulating the environmental release of genetically engineered organisms or their modified components, either during the research and development stage or during application. There are some statutes, administered by several federal agencies, whose language is broad enough to allow the extension of intended coverage to include certain aspects of biotechnology. The one possible exception is FIFRA, which has already brought about the registration of several natural microbial pesticides but which also has provision for requiring the registration of “strain improved” microbial pesticides. Nevertheless, there may be gaps in coverage even if all pertinent statutes were to be actively applied to the control of environmental release of genetically modified substances. The decision to regulate biotechnology under TSCA was justified, in part, on the basis of its intended role as a gap-filling piece of environmental legislation. The advantage of regulating biotechnology under TSCA is that this statute, unlike others, is concerned with all media of exposure (air, water, soil, sediment, biota) that may pose health and environmental hazards. Experience may show that extending existing legislation to regulate biotechnology is a poor compromise compared to the promulgation of new legislation specifically designed for this purpose. It appears that many other countries are ultimately going to take the latter course to regulate biotechnology.

  12. Computerized Numerical Control Curriculum Guide.

    ERIC Educational Resources Information Center

    Reneau, Fred; And Others

    This guide is intended for use in a course in programming and operating a computerized numerical control system. Addressed in the course are various aspects of programming and planning, setting up, and operating machines with computerized numerical control, including selecting manual or computer-assigned programs and matching them with…

  13. Models and Computational Methods for Dynamic Friction Phenomena. 1. Physical Aspects of Dynamic Friction. 2. Continuum Models and Variational Principles for Dynamic Friction. 3. Finite Element Models and Numerical Analysis

    DTIC Science & Technology

    1984-10-25

    Models and Numerical Analysis Research sponsored by the Air Force Office of Scientific Research (AFSC) under contract F49620-84-0024. The United States...frictional forces may depend upon histories of micro-tangential displacements of particles on the contact surface . Theories describing such...frictional forces developed on the contact surface appear to depend on the sliding velocity of one surface relative to another. To obtain reproducible

  14. Hindi Numerals.

    ERIC Educational Resources Information Center

    Bright, William

    In most languages encountered by linguists, the numerals, considered as a paradigmatic set, constitute a morpho-syntactic problem of only moderate complexity. The Indo-Aryan language family of North India, however, presents a curious contrast. The relatively regular numeral system of Sanskrit, as it has developed historically into the modern…

  15. Numerical Integration

    ERIC Educational Resources Information Center

    Sozio, Gerry

    2009-01-01

    Senior secondary students cover numerical integration techniques in their mathematics courses. In particular, students would be familiar with the "midpoint rule," the elementary "trapezoidal rule" and "Simpson's rule." This article derives these techniques by methods which secondary students may not be familiar with and an approach that…

  16. Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Baker, John G.

    2009-01-01

    Recent advances in numerical relativity have fueled an explosion of progress in understanding the predictions of Einstein's theory of gravity, General Relativity, for the strong field dynamics, the gravitational radiation wave forms, and consequently the state of the remnant produced from the merger of compact binary objects. I will review recent results from the field, focusing on mergers of two black holes.

  17. Numerical Optimization

    DTIC Science & Technology

    1992-12-01

    fisica matematica . ABSTRACT - We consider a new method for the numerical solution both of non- linear systems of equations and of cornplementauity... Matematica , Serie V11 Volume 9 , Roma (1989), 521-543 An Inexact Continuous Method for the Solution of Large Systems of Equations and Complementarity...34 - 00185 Roma - Italy APPENDIX 2 A Quadratically Convergent Method for Unear Programming’ Stefano Herzel Dipartimento di Matematica -G. Castelnuovo

  18. Symposium on Numerical and Physical Aspects of Aerodynamic Flows

    DTIC Science & Technology

    1992-01-15

    approach uses excellent job of capturing the wake from the main element about 20 % fewer grid points, it takes a little less comput- in this region...geometry. It is for these reasons that the overlaid 1. grid approach was adopted for the rest of the cases and -5 0 5 10 15 20 geometries in this work... grid in order to resolve the 20 - -I" /flow physics adequately in the boundary layers and wakes. -15 - -- . The grid spacing next to the surfaces of the

  19. Numerical aspects of optimal control of penicillin production.

    PubMed

    Pčolka, Matej; Celikovský, Sergej

    2014-01-01

    Since their discovery, fermentation processes have gone along not only with the industrial beverages production and breweries, but since the times of Alexander Fleming, they have become a crucial part of the health care due to antibiotics production. However, complicated dynamics and strong nonlinearities cause that the production with the use of linear control methods achieves only suboptimal yields. From the variety of nonlinear approaches, gradient method has proved the ability to handle these issues--nevertheless, its potential in the field of fermentation processes has not been revealed completely. This paper describes constant vaporization control strategy based on a double-input optimization approach with a successful reduction to a single-input optimization task. To accomplish this, model structure used in the previous work is modified so that it corresponds with the new optimization strategy. Furthermore, choice of search step is explored and various alternatives are evaluated and compared.

  20. Numerical Investigation of a Low Aspect Ratio Flat Plate

    DTIC Science & Technology

    2011-05-19

    M.R., ―High-Fidelity Simulations of Transitional Flow Over Pitching Airfoils,‖ AIAA Paper 2009- 3693 . Henshaw, W.D., and Petersson, N. A., ―A Split...Amplitude Pitch Problem: Airfoils, Plates and Wings,‖ AIAA Paper 2009-3686, 2009. OL, M.V., Altman, A., Eldredge, J.D., Garmann, D ., and Lian, Y...incompressible flow solver. AIAA J. 39,253 -260, 2001. Thomas, P. D ., and Lombard, C. K., ―Geometric Conservation Law and its Application to Flow

  1. Modulation of brain steroidogenesis by affecting transcriptional changes of steroidogenic acute regulatory (StAR) protein and cholesterol side chain cleavage (P450scc) in juvenile Atlantic salmon (Salmo salar) is a novel aspect of nonylphenol toxicity.

    PubMed

    Arukwe, Augustine

    2005-12-15

    Gene expression patterns for key brain steroidogenic (StAR, P450scc, CYP11beta) and xenobiotic- and steroid-metabolizing enzymes (CYP1A1 and CYP3A) have been investigated in waterborne nonylphenol (5, 15, and 50 microg/ L) treated juvenile Atlantic salmon (Salmo salar), in addition to carrier vehicle (ethanol) exposed fish, sampled at different time intervals (0, 3, and 7 days) after exposure. Gene expression patterns were studied using the quantitative polymerase chain reaction (real-time PCR). Treatment of juvenile salmon with nonylphenol caused significant induction of steroidogenic acute regulatory (StAR) protein mRNA at day 7 postexposure in the group receiving 15 microg of nonylphenol/L. P450scc was first induced in the group treated with 5 microg of nonylphenol/L at day 7; thereafter, an apparent nonylphenol-concentration-dependent decrease in P450scc mRNA was observed. CYP11beta mRNA was significantly induced at day 3 after exposure to 5 betag of nonylphenol/L; thereafter, CYP11beta mRNA levels were inhibited below control levels in the 15 and 50 microg of nonylphenol/L groups at day 3. At day 7, significant induction of CYP11beta mRNA was observed only in the group exposed to 15 microg of nonylphenol/L. For CYP1A1 mRNA, apparent nonylphenol-concentration-dependent decreases were observed at day 7 postexposure. CYP3A mRNA was significantly induced by all nonylphenol exposure concentrations at day 7. When exposed groups were compared, CYP3A transcript was significantly induced between 5 and 15 microg of nonylphenol/ L, and decreased between 15 and 50 microg of nonylphenol/ L. The ethanol control showed a significant reduction of CYP3A mRNA at day 3 postexposure. The present study has demonstrated variations in three key steroidogenic proteins and xenobiotic- and steroid-metabolizing CYP isoenzyme gene transcripts in the brain of nonylphenol-exposed juvenile salmon. Therefore, the present study represents a novel aspect of neuroendocrine effects of

  2. Assessment of affect integration: validation of the affect consciousness construct.

    PubMed

    Solbakken, Ole André; Hansen, Roger Sandvik; Havik, Odd E; Monsen, Jon T

    2011-05-01

    Affect integration, or the capacity to utilize the motivational and signal properties of affect for personal adjustment, is assumed to be an important aspect of psychological health and functioning. Affect integration has been operationalized through the affect consciousness (AC) construct as degrees of awareness, tolerance, nonverbal expression, and conceptual expression of nine discrete affects. A semistructured Affect Consciousness Interview (ACI) and separate Affect Consciousness Scales (ACSs) have been developed to specifically assess these aspects of affect integration. This study explored the construct validity of AC in a Norwegian clinical sample including estimates of reliability and assessment of structure by factor analyses. External validity issues were addressed by examining the relationships between scores on the ACSs and self-rated symptom- and interpersonal problem measures as well as independent, observer-based ratings of personality disorder criteria and the Global Assessment of Functioning (GAF) scale from the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994).

  3. Power Quality Aspects in a Wind Power Plant: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Chacon, J.; Romanowitz, H.

    2006-01-01

    Although many operational aspects affect wind power plant operation, this paper focuses on power quality. Because a wind power plant is connected to the grid, it is very important to understand the sources of disturbances that affect the power quality.

  4. Understanding How Grammatical Aspect Influences Legal Judgment

    PubMed Central

    Sherrill, Andrew M.; Eerland, Anita; Zwaan, Rolf A.; Magliano, Joseph P.

    2015-01-01

    Recent evidence suggests that grammatical aspect can bias how individuals perceive criminal intentionality during discourse comprehension. Given that criminal intentionality is a common criterion for legal definitions (e.g., first-degree murder), the present study explored whether grammatical aspect may also impact legal judgments. In a series of four experiments participants were provided with a legal definition and a description of a crime in which the grammatical aspect of provocation and murder events were manipulated. Participants were asked to make a decision (first- vs. second-degree murder) and then indicate factors that impacted their decision. Findings suggest that legal judgments can be affected by grammatical aspect but the most robust effects were limited to temporal dynamics (i.e., imperfective aspect results in more murder actions than perfective aspect), which may in turn influence other representational systems (i.e., number of murder actions positively predicts perceived intentionality). In addition, findings demonstrate that the influence of grammatical aspect on situation model construction and evaluation is dependent upon the larger linguistic and semantic context. Together, the results suggest grammatical aspect has indirect influences on legal judgments to the extent that variability in aspect changes the features of the situation model that align with criteria for making legal judgments. PMID:26496364

  5. Cognitive Aspects of Prejudice

    ERIC Educational Resources Information Center

    Tajfel, Henri

    1969-01-01

    This paper is a slightly revised version of a contribution to a symposium on the "Biosocial Aspects of Race," held in London, September, 1968; symposium was published in the "Journal of Biosocial Science," Supplement No. 1, July, 1969. (RJ)

  6. High Aspect Ratio Wrinkles

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Crosby, Alfred

    2015-03-01

    Buckling-induced surface undulations are widely found in living creatures, for instance, gut villi and the surface of flower petal cells. These undulations provide unique functionalities with their extremely high aspect ratios. For the synthetic systems, sinusoidal wrinkles that are induced by buckling a thin film attached on a soft substrate have been proposed to many applications. However, the impact of the synthetic wrinkles have been restricted by limited aspect ratios, ranging from 0 to 0.35. Within this range, wrinkle aspect ratio is known to increase with increasing compressive strain until a critical strain is reached, at which point wrinkles transition to localizations, such as folds or period doublings. Inspired by the living creatures, we propose that wrinkles can be stabilized in high aspect ratio by manipulating the strain energy in the substrate. We experimentally demonstrate this idea by forming a secondary crosslinking network in the wrinkled surface and successfully achieve aspect ratio as large as 0.8. This work not only provides insights for the mechanism of high aspect ratio structures seen in living creatures, but also demonstrates significant promise for future wrinkle-based applications.

  7. Affective Aspects of Language Learning: Beliefs, Attitudes, Efficacy

    ERIC Educational Resources Information Center

    Oliver, Rhonda; Purdie, Nola; Rochecouste, Judith

    2005-01-01

    The focus of this study is the relationship between language attitude, beliefs, efficacy, English language competence, and language achievement. Two hundred and eighty-five students from five metropolitan primary schools in Western Australia completed a specially designed questionnaire based on the Attitude/Motivation Test Battery (Gardner,…

  8. The Sinorhizobium meliloti stringent response affects multiple aspects of symbiosis.

    PubMed

    Wells, Derek H; Long, Sharon R

    2002-03-01

    Sinorhizobium meliloti and host legumes enter into a nitrogen-fixing, symbiotic relationship triggered by an exchange of signals between bacteria and plant. S. meliloti produces Nod factor, which elicits the formation of nodules on plant roots, and succinoglycan, an exopolysaccharide that allows for bacterial invasion and colonization of the host. The biosynthesis of these molecules is well defined, but the specific regulation of these compounds is not completely understood. Bacteria control complex regulatory networks by the production of ppGpp, the effector molecule of the stringent response, which induces physiological change in response to adverse growth conditions and can also control bacterial development and virulence. Through detailed analysis of an S. meliloti mutant incapable of producing ppGpp, we show that the stringent response is required for nodule formation and regulates the production of succinoglycan. Although it remains unknown whether these phenotypes are connected, we have isolated suppressor strains that restore both defects and potentially identify key downstream regulatory genes. These results indicate that the S. meliloti stringent response has roles in both succinoglycan production and nodule formation and, more importantly, that control of bacterial physiology in response to the plant and surrounding environment is critical to the establishment of a successful symbiosis.

  9. Affect and Self-Regulation

    ERIC Educational Resources Information Center

    Malmivuori, Marja-Liisa

    2006-01-01

    This paper presents affect as an essential aspect of students' self-reflection and self-regulation. The introduced concepts of self-system and self-system process stress the importance of self-appraisals of personal competence and agency in affective responses and self-regulation in problem solving. Students are viewed as agents who constantly…

  10. Requirements Engineering and Aspects

    NASA Astrophysics Data System (ADS)

    Yu, Yijun; Niu, Nan; González-Baixauli, Bruno; Mylopoulos, John; Easterbrook, Steve; Do Prado Leite, Julio Cesar Sampaio

    A fundamental problem with requirements engineering (RE) is to validate that a design does satisfy stakeholder requirements. Some requirements can be fulfilled locally by designed modules, where others must be accommodated globally by multiple modules together. These global requirements often crosscut with other local requirements and as such lead to scattered concerns. We explore the possibility of borrowing concepts from aspect-oriented programming (AOP) to tackle these problems in early requirements. In order to validate the design against such early aspects, we propose a framework to trace them into coding and testing aspects. We demonstrate the approach using an open-source e-commerce platform. In the conclusion of this work, we reflect on the lessons learnt from the case study on how to fit RE and AOP research together.

  11. Organisational aspects of care.

    PubMed

    Bloomfield, Jacqueline; Pegram, Anne

    2015-03-04

    Organisational aspects of care, the second essential skills cluster, identifies the need for registered nurses to systematically assess, plan and provide holistic patient care in accordance with individual needs. Safeguarding, supporting and protecting adults and children in vulnerable situations; leading, co-ordinating and managing care; functioning as an effective and confident member of the multidisciplinary team; and managing risk while maintaining a safe environment for patients and colleagues, are vital aspects of this cluster. This article discusses the roles and responsibilities of the newly registered graduate nurse. Throughout their education, nursing students work towards attaining this knowledge and these skills in preparation for their future roles as nurses.

  12. [Phytic acid: nutritional aspects and analytical implications].

    PubMed

    Martínez Domínguez, Beatriz; Ibáñez Gómez, M Victoria; Rincón León, Francisco

    2002-09-01

    This review provides a current summary of the literature concerning various aspects of phytic acid. These include data relative to its chemical structure and physicochemical properties, its occurrence in numerous cereals and legumes, and its role in plants. In addition, the nutritional significance of phytate with regard to its protein and mineral binding abilities, its health benefits and the methods commonly used for the analysis of phytate are discussed.

  13. Numerical ability predicts mortgage default.

    PubMed

    Gerardi, Kristopher; Goette, Lorenz; Meier, Stephan

    2013-07-09

    Unprecedented levels of US subprime mortgage defaults precipitated a severe global financial crisis in late 2008, plunging much of the industrialized world into a deep recession. However, the fundamental reasons for why US mortgages defaulted at such spectacular rates remain largely unknown. This paper presents empirical evidence showing that the ability to perform basic mathematical calculations is negatively associated with the propensity to default on one's mortgage. We measure several aspects of financial literacy and cognitive ability in a survey of subprime mortgage borrowers who took out loans in 2006 and 2007, and match them to objective, detailed administrative data on mortgage characteristics and payment histories. The relationship between numerical ability and mortgage default is robust to controlling for a broad set of sociodemographic variables, and is not driven by other aspects of cognitive ability. We find no support for the hypothesis that numerical ability impacts mortgage outcomes through the choice of the mortgage contract. Rather, our results suggest that individuals with limited numerical ability default on their mortgage due to behavior unrelated to the initial choice of their mortgage.

  14. Sociological Aspects of Deafness.

    ERIC Educational Resources Information Center

    World Federation of the Deaf, Rome (Italy).

    Nine conference papers treat the sociological aspects of deafness. Included are "Individuals Being Deaf and Blind and Living with a Well Hearing Society" by A. Marx (German Federal Republic), "A Deaf Man's Experiences in a Hearing World" by A. B. Simon(U.S.A.), "Problem of Text Books and School Appliances for Vocational…

  15. Aspects of Marine Ecology.

    ERIC Educational Resources Information Center

    Awkerman, Gary L.

    This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations to impart ocean science understanding, specifically, aspects of marine ecology, to high school students. The course objectives include the ability of…

  16. Global aspects of monsoons

    NASA Technical Reports Server (NTRS)

    Murakami, T.

    1985-01-01

    Recent developments are studied in three areas of monsoon research: (1) global aspects of the monsoon onset, (2) the orographic influence of the Tibetan Plateau on the summer monsoon circulations, and (3) tropical 40 to 50 day oscillations. Reference was made only to those studies that are primarily based on FGGE Level IIIb data. A brief summary is given.

  17. Medical Aspects of Surfing.

    ERIC Educational Resources Information Center

    Renneker, Mark

    1987-01-01

    The medical aspects of surfing include ear and eye injuries and sprains and strains of the lower back and neck, as well as skin cancer from exposure to the sun. Treatment, rehabilitation, and prevention of these problems are discussed. Surfing is recommended as part of an exercise program for reasonably healthy people. (Author/MT)

  18. Ethical aspects on rare diseases.

    PubMed

    Barrera, Luis A; Galindo, Gilberto Cely

    2010-01-01

    In this chapter we discuss several of the most relevant subjects related to ethics on Rare Diseases. Some general aspects are discussed such as the socio-psychological problems that confront the patients and their families that finally lead to marginalization and exclusion of patients affected by these diseases from the health programs, even in wealthy countries. Then we address problems related to diagnosis and some ethical aspects of newborn screening, prenatal, pre-implantation diagnosis and reference centers, as well as some conditions that should be met by the persons and institutions performing such tasks. Alternatives of solutions for the most critical situations are proposed. Subsequently the orphan drugs subject is discussed not only from the availability point of view, prizes, industrial practices, and purchasing power in developed and developing societies. The research related to rare disease in children and other especially vulnerable conditions, the need for informed consent, review boards or ethics comities, confidentiality of the information, biobanks and pharmacogenetics are discussed.

  19. Behavioural aspects of terrorism.

    PubMed

    Leistedt, Samuel J

    2013-05-10

    Behavioural and social sciences are useful in collecting and analysing intelligence data, understanding terrorism, and developing strategies to combat terrorism. This article aims to examine the psychopathological concepts of terrorism and discusses the developing roles for behavioural scientists. A systematic review was conducted of studies investigating behavioural aspects of terrorism. These studies were identified by a systematic search of databases, textbooks, and a supplementary manual search of references. Several fundamental concepts were identified that continue to influence the motives and the majority of the behaviours of those who support or engage in this kind of specific violence. Regardless of the psychological aspects and new roles for psychiatrists, the behavioural sciences will continue to be called upon to assist in developing better methods to gather and analyse intelligence, to understand terrorism, and perhaps to stem the radicalisation process.

  20. Fast Numerical Methods for Stochastic Partial Differential Equations

    DTIC Science & Technology

    2016-04-15

    uncertainty quantification. In the last decade much progress has been made in the construction of numerical algorithms to efficiently solve SPDES with...applicable SPDES with efficient numerical methods. This project is intended to address the numerical analysis as well as algorithm aspects of SPDES. Three...differential equations. Our work contains algorithm constructions, rigorous error analysis, and extensive numerical experiments to demonstrate our algorithm

  1. Aspects of B physics

    SciTech Connect

    Gaillard, M.K.

    1987-10-14

    Various aspects of weak decays are commented on. Probing of the standard model and of phenomena beyond the standard model are discussed, followed by a theoretical view of B mesons and some experimental observations on B mesons. The point is made that any data on B decay would be interesting in that it would provide powerful new constraints in analyses of the standard model and extensions thereof. (LEW)

  2. Numerical study of forced convective heat transfer around airships

    NASA Astrophysics Data System (ADS)

    Dai, Qiumin; Fang, Xiande

    2016-02-01

    Forced convective heat transfer is an important factor that affects the thermal characteristics of airships. In this paper, the steady state forced convective heat transfer around an ellipsoid is numerically investigated. The numerical simulation is carried out by commercial computational fluid dynamic (CFD) software over the extended Re range from 20 to 108 and the aspect ratio from 2 to 4. Based on the regression and optimization with software, a new piecewise correlation of the Nusselt number at constant wall temperature for ellipsoid is proposed, which is suitable for applications to airships and other ellipse shaped bodies such as elliptical balloons. The thermal characteristics of a stratospheric airship in midsummer located in the north hemisphere are numerical studied. The helium temperature predicated using the new correlation is compared to those predicted by correlations applicable for spheres and flat plates. The results show that the helium temperature obtained using the new correlation at noon is about 5.4 K lower than that using the correlation of spheres and about 2.1 K higher than that of flat plates.

  3. Computerized Numerical Control Test Item Bank.

    ERIC Educational Resources Information Center

    Reneau, Fred; And Others

    This guide contains 285 test items for use in teaching a course in computerized numerical control. All test items were reviewed, revised, and validated by incumbent workers and subject matter instructors. Items are provided for assessing student achievement in such aspects of programming and planning, setting up, and operating machines with…

  4. Juvenile onset spondyloarthropathies: therapeutic aspects

    PubMed Central

    Burgos-Vargas, R

    2002-01-01

    Juvenile onset spondyloarthropathy (SpA) is a term that refers to a group of human leucocyte antigen (HLA)-B27 associated inflammatory disorders affecting children under the age of 16 years, producing a continuum of clinical symptoms through adulthood. This disease is characterised by enthesopathy and arthropathy affecting the joints of the lower extremities and seronegativity for IgM rheumatoid factor and antinuclear antibodies. Children usually present with undifferentiated SpA and progress to differentiated forms over time. Except for the prevalence of some clinical features at onset, the pathogenic and clinical aspects of juvenile onset SpAs resemble those of the adult disease. Thus application of the same or similar therapeutic measures for both juvenile and adult onset SpAs seems logical. Current treatments for juvenile onset SpA provide symptomatic improvement, but do not alter disease progression. The increased expression of tumour necrosis factor alpha (TNFα) in synovial tissue of patients with adult and juvenile onset SpA and its correlation with infiltration of inflammatory mediators into the synovia suggest a significant pathogenic role of this cytokine. Clinical trials of anti-TNFα antibody (infliximab) therapy in patients with adult onset SpA have demonstrated significant clinical improvement in inflammatory pain, function, disease activity, and quality of life in correlation with histological and immunohistochemical evidence of modulation of synovial inflammatory processes. These promising findings suggest that anti-TNFα therapy may confer similar benefits in patients with juvenile onset SpA. PMID:12381509

  5. Global Aspects of Radiation Memory

    NASA Astrophysics Data System (ADS)

    Winicour, Jeffrey

    2015-04-01

    The gravitational radiation memory effect produces a net displacement of test particles. The proposed sources lead to E mode memory, as characterized by an even parity polarization pattern. Although odd parity, or B mode, radiation memory is mathematically possible, no physically realistic source has been identified. There is an electromagnetic counterpart to radiation memory which produces a net momentum ``kick'' of charged test particles. A global null cone treatment shows that electromagnetic E mode memory requires unbounded charges and no physically realistic source produces B mode memory. A compelling theoretical aspect of E mode gravitational radiation memory is related to the supertranslations in the Bondi-Metzner-Sachs (BMS) asymptotic symmetry group. For a stationary system, supertranslations can be eliminated and the BMS group reduced to the Poincare group, for which angular momentum is well-defined. However, for a stationary to stationary transition, the two Poincare groups obtained at early and late times differ by a supertranslation if the gravitational radiation has nonzero E mode memory. This suggests a distinctly general relativistic mechanism for angular momentum loss and presents a ripe problem for the numerical simulation of high spin black hole binaries. Supported by NSF grant PHY-1201276 to the University of Pittsburgh.

  6. The effect of aspect ratio on adhesion and stiffness for soft elastic fibres

    PubMed Central

    Aksak, Burak; Hui, Chung-Yuen; Sitti, Metin

    2011-01-01

    The effect of aspect ratio on the pull-off stress and stiffness of soft elastic fibres is studied using elasticity and numerical analysis. The adhesive interface between a soft fibre and a smooth rigid surface is modelled using the Dugdale–Barenblatt model. Numerical simulations show that, while pull-off stress increases with decreasing aspect ratio, fibres get stiffer. Also, for sufficiently low aspect ratio fibres, failure occurs via the growth of internal cracks and pull-off stress approaches the intrinsic adhesive strength. Experiments carried out with various aspect ratio polyurethane elastomer fibres are consistent with the numerical simulations. PMID:21227962

  7. Effects of building aspect ratio, diurnal heating scenario, and wind speed on reactive pollutant dispersion in urban street canyons.

    PubMed

    Tong, Nelson Y O; Leung, Dennis Y C

    2012-01-01

    A photochemistry coupled computational fluid dynamics (CFD) based numerical model has been developed to model the reactive pollutant dispersion within urban street canyons, particularly integrating the interrelationship among diurnal heating scenario (solar radiation affections in nighttime, daytime, and sun-rise/set), wind speed, building aspect ratio (building-height-to-street-width), and dispersion of reactive gases, specifically nitric oxide (NO), nitrogen dioxide (NO2) and ozone (O3) such that a higher standard of air quality in metropolitan cities can be achieved. Validation has been done with both experimental and numerical results on flow and temperature fields in a street canyon with bottom heating, which justifies the accuracy of the current model. The model was applied to idealized street canyons of different aspect ratios from 0.5 to 8 with two different ambient wind speeds under different diurnal heating scenarios to estimate the influences of different aforementioned parameters on the chemical evolution of NO, NO2 and O3. Detailed analyses of vertical profiles of pollutant concentrations showed that different diurnal heating scenarios could substantially affect the reactive gases exchange between the street canyon and air aloft, followed by respective dispersion and reaction. Higher building aspect ratio and stronger ambient wind speed were revealed to be, in general, responsible for enhanced entrainment of O3 concentrations into the street canyons along windward walls under all diurnal heating scenarios. Comparatively, particular attention can be paid on the windward wall heating and nighttime uniform surface heating scenarios.

  8. Chiral models: Geometrical aspects

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.

    1987-02-01

    Two-dimensional classical chiral models of field theory are considered, the main attention being paid on geometrical aspects of such theories. A characteristic feature of these models is that the interaction is inserted not by adding the interaction Lagrangian to the free field Lagrangian, but has a purely geometrical origin and is related to the inner curvature of the manifold. These models are in many respects analogous to non-Abelian gauge theories and as became clear recently, they are also important for the superstring theory which nowadays is the most probable candidate for a truly unified theory of all interactions including gravitation.

  9. Numerical errors in the presence of steep topography: analysis and alternatives

    SciTech Connect

    Lundquist, K A; Chow, F K; Lundquist, J K

    2010-04-15

    It is well known in computational fluid dynamics that grid quality affects the accuracy of numerical solutions. When assessing grid quality, properties such as aspect ratio, orthogonality of coordinate surfaces, and cell volume are considered. Mesoscale atmospheric models generally use terrain-following coordinates with large aspect ratios near the surface. As high resolution numerical simulations are increasingly used to study topographically forced flows, a high degree of non-orthogonality is introduced, especially in the vicinity of steep terrain slopes. Numerical errors associated with the use of terrainfollowing coordinates can adversely effect the accuracy of the solution in steep terrain. Inaccuracies from the coordinate transformation are present in each spatially discretized term of the Navier-Stokes equations, as well as in the conservation equations for scalars. In particular, errors in the computation of horizontal pressure gradients, diffusion, and horizontal advection terms have been noted in the presence of sloping coordinate surfaces and steep topography. In this work we study the effects of these spatial discretization errors on the flow solution for three canonical cases: scalar advection over a mountain, an atmosphere at rest over a hill, and forced advection over a hill. This study is completed using the Weather Research and Forecasting (WRF) model. Simulations with terrain-following coordinates are compared to those using a flat coordinate, where terrain is represented with the immersed boundary method. The immersed boundary method is used as a tool which allows us to eliminate the terrain-following coordinate transformation, and quantify numerical errors through a direct comparison of the two solutions. Additionally, the effects of related issues such as the steepness of terrain slope and grid aspect ratio are studied in an effort to gain an understanding of numerical domains where terrain-following coordinates can successfully be used and

  10. Numerical Sensitivity Analysis of a Composite Impact Absorber

    NASA Astrophysics Data System (ADS)

    Caputo, F.; Lamanna, G.; Scarano, D.; Soprano, A.

    2008-08-01

    This work deals with a numerical investigation on the energy absorbing capability of structural composite components. There are several difficulties associated with the numerical simulation of a composite impact-absorber, such as high geometrical non-linearities, boundary contact conditions, failure criteria, material behaviour; all those aspects make the calibration of numerical models and the evaluation of their sensitivity to the governing geometrical, physical and numerical parameters one of the main objectives of whatever numerical investigation. The last aspect is a very important one for designers in order to make the application of the model to real cases robust from both a physical and a numerical point of view. At first, on the basis of experimental data from literature, a preliminary calibration of the numerical model of a composite impact absorber and then a sensitivity analysis to the variation of the main geometrical and material parameters have been developed, by using explicit finite element algorithms implemented in the Ls-Dyna code.

  11. Recent Developments in the Community Code ASPECT

    NASA Astrophysics Data System (ADS)

    Heister, T.; Bangerth, W.; Dannberg, J.; Gassmoeller, R.

    2015-12-01

    The Computational Geosciences have long used community codes to provide simulation capabilities to large numbers of users. We here report on the mantle convection code ASPECT (the Advanced Solver for Problems in Earth ConvecTion) that is developed to be a community tool with a focus on bringing modern numerical methods such as adaptive meshes, large parallel computations, algebraic multigrid solvers, and modern software design. We will comment in particular on two aspects: First, the more recent additions to its numerical capabilities, such as compressible models, averaging of material parameters, melt transport, free surfaces, and plasticity. We will demonstrate these capabilities using examples from computations by members of the ASPECT user community. Second, we will discuss lessons learned in writing a code specifically for community use. This includes our experience with a software design that is fundamentally based on a plugin system for practically all areas that a user may want to describe for the particular geophysical setup they want to simulate. It also includes our experience with leading and organizing a community of users and developers, for example by organizing annual "hackathons", by encouraging code submission via github over keeping modifications private, and by designing a code for which extensions can easily be written as separate plugins rather than requiring knowledge of the computational core.

  12. Aspects of Gond astronomy

    NASA Astrophysics Data System (ADS)

    Vahia, M. N.; Halkare, Ganesh

    2013-03-01

    The Gond community is considered to be one of the most ancient tribes of India with a continuing history of several thousand years. They are also known for their largely isolated history which they have retained through the millennia. Several of their intellectual traditions therefore are a record of parallel aspects of human intellectual growth, and still preserve their original flavour and have not been homogenised by the later traditions of India. In view of this, the Gonds provide a special window to the different currents that constitute contemporary India. In the present study, we summarise their mythology, genetics and script. We then investigate their astronomical traditions and try to understand this community through a survey of 15 Gond villages spread over Maharashtra, Andhra Pradesh and Madhya Pradesh. We show that they have a distinctly different view of the sky from the conventional astronomical ideas encountered elsewhere in India, which is both interesting and informative. We briefly comment on other aspects of their life as culled from our encounters with different members of the Gond community.

  13. Veterinary aspects of salmonid fish farming: husbandry diseases.

    PubMed

    Shepherd, C J; Poupard, C W

    1975-07-19

    Most disease problems affecting farmed salmonid fish are either caused or exacerbated by bad husbandry and poor environmental conditions. The aspects of water quality and nutrition which are significant in causing husbandry problems are considered. The clinical aspects of these diseases are decribed in terms of the life cycle of salmonids, and methods of prevention are discussed.

  14. 25 CFR 87.9 - Programming aspects of plans.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Programming aspects of plans. 87.9 Section 87.9 Indians... JUDGMENT FUNDS § 87.9 Programming aspects of plans. In assessing any tribal programming proposal the... such reservation residents; the nature of recent programming affecting the subject tribe or group...

  15. 25 CFR 87.9 - Programming aspects of plans.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Programming aspects of plans. 87.9 Section 87.9 Indians... JUDGMENT FUNDS § 87.9 Programming aspects of plans. In assessing any tribal programming proposal the... such reservation residents; the nature of recent programming affecting the subject tribe or group...

  16. 25 CFR 87.9 - Programming aspects of plans.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Programming aspects of plans. 87.9 Section 87.9 Indians... JUDGMENT FUNDS § 87.9 Programming aspects of plans. In assessing any tribal programming proposal the... such reservation residents; the nature of recent programming affecting the subject tribe or group...

  17. 25 CFR 87.9 - Programming aspects of plans.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Programming aspects of plans. 87.9 Section 87.9 Indians... JUDGMENT FUNDS § 87.9 Programming aspects of plans. In assessing any tribal programming proposal the... such reservation residents; the nature of recent programming affecting the subject tribe or group...

  18. 25 CFR 87.9 - Programming aspects of plans.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Programming aspects of plans. 87.9 Section 87.9 Indians... JUDGMENT FUNDS § 87.9 Programming aspects of plans. In assessing any tribal programming proposal the... such reservation residents; the nature of recent programming affecting the subject tribe or group...

  19. [The physiotherapic aspect of omeral epicondilitis (author's transl)].

    PubMed

    Marenghi, P; Tella, G C

    1976-01-01

    The Authors describe history, etiopatogenesis, clinic, therapy of omeral epicondilitis, very frequent affection. Physiotherapic aspects are studied by different methods. The indications are different compared to clinical aspect, pain modality, relapse eventuality. They conclude with personal considerations based on what observed in Orthopedic Clinica of Parma University.

  20. Affect, Behavioural Schemas and the Proving Process

    ERIC Educational Resources Information Center

    Selden, Annie; McKee, Kerry; Selden, John

    2010-01-01

    In this largely theoretical article, we discuss the relation between a kind of affect, behavioural schemas and aspects of the proving process. We begin with affect as described in the mathematics education literature, but soon narrow our focus to a particular kind of affect--nonemotional cognitive feelings. We then mention the position of feelings…

  1. Aspects, Wrappers and Events

    NASA Technical Reports Server (NTRS)

    Filman, Robert E.

    2003-01-01

    This viewgraph presentation provides information on Object Infrastructure Framework (OIF), an Aspect-Oriented Programming (AOP) system. The presentation begins with an introduction to the difficulties and requirements of distributed computing, including functional and non-functional requirements (ilities). The architecture of Distributed Object Technology includes stubs, proxies for implementation objects, and skeletons, proxies for client applications. The key OIF ideas (injecting behavior, annotated communications, thread contexts, and pragma) are discussed. OIF is an AOP mechanism; AOP is centered on: 1) Separate expression of crosscutting concerns; 2) Mechanisms to weave the separate expressions into a unified system. AOP is software engineering technology for separately expressing systematic properties while nevertheless producing running systems that embody these properties.

  2. Sprirtual aspects of psychotherapy.

    PubMed

    Prasinos, S

    1992-03-01

    This article addresses the relevance of spirituality to psychology and psychotherapy. It argues that spiritual experience is phenomenologically legitimate and worthy of study, especially by students of mental health. It utilizes Fox's (1985) definition of spirituality as "unitive experience" to show that spiritual experience is often present, overtly or covertly, within the ritual of psychotherapy. The paper argues that the therapist's adoption of an empathic posture is essentially a spiritual position. This position consists of a sense of peace, eternity, forgiveness, faith, love, truth, and God. These aspects are part of an integrated spiritual gestalt which is, though generally unacknowledged, fundamental to the communal healing process of psychotherapy. The paper concludes by asserting that greater involvement with the unitive (as opposed to the disunitive) represents a positive paradigmatic shift for psychology and humanity.

  3. Historical aspects of anxiety

    PubMed Central

    Klein, Donald F.

    2002-01-01

    “Anxiety” is a key term for behavioral, psychoanalytic, neuroendocrine, and psychopharmacological observations and theories. Commenting on its historical aspects is difficult, since history is properly a study of primary data. Unfortunately, much clinical anecdote does not correspond to factual records of a long time ago. Even reports of objective studies may suffer from allegiance effects. This essay therefore primarily reflects the personal impact of others' work against the background of my experiences, clinical and scientific. These lead me to question the assumption that “anxiety”, as it exists in syndromal disturbances, is simply the quantitative extreme of the normal “anxiety” that occurs during the anticipation of danger. An alternative view that emphasizes dysfunctions of distinct evolved adaptive alarm systems is presented. PMID:22033777

  4. Aspects of Plant Intelligence

    PubMed Central

    TREWAVAS, ANTHONY

    2003-01-01

    Intelligence is not a term commonly used when plants are discussed. However, I believe that this is an omission based not on a true assessment of the ability of plants to compute complex aspects of their environment, but solely a reflection of a sessile lifestyle. This article, which is admittedly controversial, attempts to raise many issues that surround this area. To commence use of the term intelligence with regard to plant behaviour will lead to a better understanding of the complexity of plant signal transduction and the discrimination and sensitivity with which plants construct images of their environment, and raises critical questions concerning how plants compute responses at the whole‐plant level. Approaches to investigating learning and memory in plants will also be considered. PMID:12740212

  5. Numerical Boundary Condition Procedures

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Topics include numerical procedures for treating inflow and outflow boundaries, steady and unsteady discontinuous surfaces, far field boundaries, and multiblock grids. In addition, the effects of numerical boundary approximations on stability, accuracy, and convergence rate of the numerical solution are discussed.

  6. [Interfamilial violence, medicolegal and ethical aspects].

    PubMed

    Beauthier, J P

    2010-09-01

    Domestic or interfamilial violence--which is certainly not confined to disadvantaged social or cultural classes--is a process in which one partner carries against his spouse within the framework of private and privileged relationship (marriage, cohabitation, etc.), aggressive, violent and destructive behavior. All sectors of society are affected, whether urban or rural, and regardless of education or ethnic origin or religion. Such violence particularly affects women, but there are also violence perpetrated against men. This violence can take many forms, but we will only consider here the forensic clinical aspects, emphasizing the relevant legislation and medical ethics.

  7. Current aspects of occupational chemical carcinogenesis

    NASA Technical Reports Server (NTRS)

    Lassiter, D.

    1975-01-01

    The history of measures to control occupational exposure to carcinogenic substances is reviewed. Health hazards associated with exposure to a certain chemical substance must be considered not only from the aspects of its acute or chronic toxicity, but also from its potential to produce tumors (latent effect). There can be no clear distinction between classic toxicity and oncogenesis until the mechanisms of both are completely understood for a given chemical substance. The assessment of carcinogenic potential for a specific substance must include the consideration of published information, monitoring and control data from the affected industry, and the in-depth epidemiologic experience of affected employees.

  8. On virial analysis at low aspect ratio

    DOE PAGES

    Bongard, Michael W.; Barr, Jayson L.; Fonck, Raymond J.; ...

    2016-07-28

    The validity of virial analysis to infer global MHD equilibrium poloidal beta βp and internal inductance ℓi from external magnetics measurements is examined for low aspect ratio configurations with A < 2. Numerical equilibrium studies at varied aspect ratio are utilized to validate the technique at finite aspect ratio. The effect of applying high-A approximations to low-A experimental data is quantified and demonstrates significant over-estimation of stored energy (factors of 2–10) in spherical tokamak geometry. Experimental approximations to equilibrium-dependent volume integral terms in the analysis are evaluated at low-A. Highly paramagnetic configurations are found to be inadequately represented through themore » virial mean radius parameter RT. Alternate formulations for inferring βp and ℓi that are independent of RT to avoid this difficulty are presented for the static isotropic limit. Lastly, these formulations are suitable for fast estimation of tokamak stored energy components at low aspect ratio using virial analysis.« less

  9. On virial analysis at low aspect ratio

    SciTech Connect

    Bongard, Michael W.; Barr, Jayson L.; Fonck, Raymond J.; Reusch, Joshua A.; Thome, Kathreen E.

    2016-07-28

    The validity of virial analysis to infer global MHD equilibrium poloidal beta βp and internal inductance ℓi from external magnetics measurements is examined for low aspect ratio configurations with A < 2. Numerical equilibrium studies at varied aspect ratio are utilized to validate the technique at finite aspect ratio. The effect of applying high-A approximations to low-A experimental data is quantified and demonstrates significant over-estimation of stored energy (factors of 2–10) in spherical tokamak geometry. Experimental approximations to equilibrium-dependent volume integral terms in the analysis are evaluated at low-A. Highly paramagnetic configurations are found to be inadequately represented through the virial mean radius parameter RT. Alternate formulations for inferring βp and ℓi that are independent of RT to avoid this difficulty are presented for the static isotropic limit. Lastly, these formulations are suitable for fast estimation of tokamak stored energy components at low aspect ratio using virial analysis.

  10. Environmental aspects of wastewater reclamation.

    PubMed

    Sharma, Sunil; Choudhary, Mahendra Pratap

    2007-07-01

    The population is increasing rapidly and the demand for water by cities, industries and agriculture has tended to grow even faster than the population. Wastewater reclamation consists of a combination of conventional and advanced treatment processes employed to return a wastewater to nearly original quality, reclaiming the water. The environmental health aspects associated with reclamation of wastewater include quality aspects and public health aspects. An attempt has been made in the present paper to describe these aspects and to suggest appropriate solutions.

  11. Health-Related Aspects of Milk Proteins

    PubMed Central

    Davoodi, Seyed Hossein; Shahbazi, Roghiyeh; Esmaeili, Saeideh; Sohrabvandi, Sara; Mortazavian, AmirMohamamd; Jazayeri, Sahar; Taslimi, Aghdas

    2016-01-01

    Milk is an important component of a balanced diet and contains numerous valuable constituents. Considerable acclaimed health benefits of milk are related to its proteins, not only for their nutritive value but also for their biological properties. Scientific evidence suggests that anticarcinogenic activities, antihypertensive properties, immune system modulation, and other metabolic features of milk, are affiliated with its proteins (intact proteins or its derivatives). In this article, the main health-related aspects of milk proteins, such as anticarcinogenic, immunomodulatory, antimicrobial, anticariogenic, antihypertensive, and hypocholesterolemic effects are reviewed. Collectively, the findings indicate the effectiveness of milk proteins on reduction of risk factors for cancer, cardiovascular diseases and overall improvement of health aspects. PMID:27980594

  12. Numerical accuracy assessment

    NASA Astrophysics Data System (ADS)

    Boerstoel, J. W.

    1988-12-01

    A framework is provided for numerical accuracy assessment. The purpose of numerical flow simulations is formulated. This formulation concerns the classes of aeronautical configurations (boundaries), the desired flow physics (flow equations and their properties), the classes of flow conditions on flow boundaries (boundary conditions), and the initial flow conditions. Next, accuracy and economical performance requirements are defined; the final numerical flow simulation results of interest should have a guaranteed accuracy, and be produced for an acceptable FLOP-price. Within this context, the validation of numerical processes with respect to the well known topics of consistency, stability, and convergence when the mesh is refined must be done by numerical experimentation because theory gives only partial answers. This requires careful design of text cases for numerical experimentation. Finally, the results of a few recent evaluation exercises of numerical experiments with a large number of codes on a few test cases are summarized.

  13. Some Considerations on the FE Simulation of Orthogonal Cutting Using Different Classes of Numerical Codes

    NASA Astrophysics Data System (ADS)

    Rizzuti, Stefania; Filice, Luigino; Umbrello, Domenico

    2007-05-01

    Numerical simulation of machining is now evolving toward new directions, in particular taking into account 3D applications. On the other hand, some aspects are still not well solved and different software are today available to carry out fundamental analysis on orthogonal cutting. Some of these codes are very user-friendly but don't allow any tuning of the parameters. Other ones, are "open codes" and permit a suitable set-up of the parameters, allowing the possibility to reach better results even if their use is reserved to the specialists. However, both the categories are affected by some problems when the analysis of different parameters is run. Probably global considerations on all the database on which these codes are based are interesting as well as any discussion about the implemented mathematical formulation. Some of the above aspects, in particular focused on the role played by friction, are discussed in the paper.

  14. Research on numerical algorithms for large space structures

    NASA Technical Reports Server (NTRS)

    Denman, E. D.

    1982-01-01

    Numerical algorithms for large space structures were investigated with particular emphasis on decoupling method for analysis and design. Numerous aspects of the analysis of large systems ranging from the algebraic theory to lambda matrices to identification algorithms were considered. A general treatment of the algebraic theory of lambda matrices is presented and the theory is applied to second order lambda matrices.

  15. Numerical methods for problems involving the Drazin inverse

    NASA Technical Reports Server (NTRS)

    Meyer, C. D., Jr.

    1979-01-01

    The objective was to try to develop a useful numerical algorithm for the Drazin inverse and to analyze the numerical aspects of the applications of the Drazin inverse relating to the study of homogeneous Markov chains and systems of linear differential equations with singular coefficient matrices. It is felt that all objectives were accomplished with a measurable degree of success.

  16. Modern Perspectives in Applied Mathematics: Theory and Numerics of PDEs

    DTIC Science & Technology

    2015-04-13

    SECURITY CLASSIFICATION OF: The International Conference on “Modern Perspectives in Applied Mathematics : Theory and Numerics of PDEs” took place April... mathematics , focusing on theoretical, computational and applied aspects of partial differential equations. The meeting brought together researchers from...Release; Distribution Unlimited Final Report: Modern Perspectives in Applied Mathematics : Theory and Numerics of PDEs The views, opinions and/or

  17. Emerging therapeutic aspects in oncology

    PubMed Central

    MacEwan, David J

    2013-01-01

    Cancer remains a peculiarly stubborn disease to treat. Some forms of cancer have seen tremendous advances in the effectiveness of their treatments, whereas other forms have remained resistant to pharmacological control. This lack of hope for success is in part due to the types of drugs that are used in the clinic, and the targeted biological system being based purely on cellular growth rates. However, recent drugs designed to affect specific signalling pathways or proteins have been showing much success. Thanks to the ingenuity of pharmacologists in understanding and targeting these processes, there have been real improvements in treatment. Here we are presented with some of the research into such critical systems that have to be understood, so that they can be conquered. We will also look at the challenges facing cancer pharmacologists and what the field may present to us all in the future. Linked Articles This article is part of a themed section on Emerging Therapeutic Aspects in Oncology. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-8 PMID:23889318

  18. [Legal aspects of ritual circumcision].

    PubMed

    Schreiber, M; Schott, G E; Rascher, W; Bender, A W

    2009-12-01

    Female circumcision (genital mutilation) is a criminal violation of human rights under German law. Even with consent of the person to be circumcised and/or her legal representative this procedure must not be carried out since a consent to female circumcision is unethical and therefore void. As much consent as there is on female circumcision the legal situation with ritual male circumcision is very unclear. In practice and unnoticed by the public male circumcision is carried out - be it for medical or ritual reasons - without deeper-going reflexions on the clearness of the medical indication or the legal situation with ritual circumcision. From the medical aspect there are big differences between female and male circumcision but also certain parallels. Various reasons, partly founded in prejudice and misinformation, make people refrain from regarding circumcision of boys also as illegal. Contrary to the prevailing opinion male circumcision also represents a bodily harm which a doctor can only carry out after a preoperative interview and with the consent of the affected person. Since ritual male circumcision does not serve the wellbeing of a child it is not possible for the parents to give their consent to the circumcision in lieu of the child. Male circumcision is only permitted if the child has given his consent and is thus only legally permitted if the child has reached an age at which he is mature enough to understand the meaning and extent of such an action which is hardly the case before he has completed his 16 (th) year.

  19. Patterns in small aspect ratio Bénard-Marangoni convection.

    PubMed

    Ramón, M L; Maza, D; Mancini, H L

    1999-10-01

    An experimental study of pattern formation in Bénard-Marangoni convection with small aspect ratio containers and high Prandtl number fluids is presented. The observed stationary patterns complete previous experimental works performed at different values of aspect ratio and supercriticality. Detailed experimental studies of the flow in some single structures are described, and spatial bifurcations between different stationary planforms for a fixed aspect ratio are shown. These experimental results agree qualitatively with linear theory analysis and with some previous numerical works about boundary conditions effects.

  20. Gastric cancer: basic aspects.

    PubMed

    Resende, Carlos; Thiel, Alexandra; Machado, José C; Ristimäki, Ari

    2011-09-01

    Gastric cancer (GC) is a world health burden, ranging as the second cause of cancer death worldwide. Etiologically, GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations. In the last years, molecular oncobiology studies brought to light a number of genes that are implicated in gastric carcinogenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variants of the genes IL-10, IL-17, MUC1, MUC6, DNMT3B, SMAD4, and SERPINE1 have been reported to modify the risk of developing GC. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (GSK3β, CD133, DSC2, P-Cadherin, CDH17, CD168, CD44, metalloproteinases MMP7 and MMP11, and a subset of miRNAs) and through tumor suppressor gene inactivation mechanisms (TFF1, PDX1, BCL2L10, XRCC, psiTPTE-HERV, HAI-2, GRIK2, and RUNX3). It also addressed the role of the inflammatory mediator cyclooxygenase-2 (COX-2) in the process of gastric carcinogenesis and its importance as a potential molecular target for therapy.

  1. Immunological aspects of atherosclerosis.

    PubMed

    Woollard, Kevin J

    2013-09-01

    Cardiovascular disease is the leading cause of death in several countries. The underlying process is atherosclerosis, a slowly progressing chronic disorder that can lead to intravascular thrombosis. There is overwhelming evidence for the underlying importance of our immune system in atherosclerosis. Monocytes, which comprise part of the innate immune system, can be recruited to inflamed endothelium and this recruitment has been shown to be proportional to the extent of atherosclerotic disease. Monocytes undergo migration into the vasculature, they differentiate into macrophage phenotypes, which are highly phagocytic and can scavenge modified lipids, leading to foam cell formation and development of the lipid-rich atheroma core. This increased influx leads to a highly inflammatory environment and along with other immune cells can increase the risk in the development of the unstable atherosclerotic plaque phenotype. The present review provides an overview and description of the immunological aspect of innate and adaptive immune cell subsets in atherosclerosis, by defining their interaction with the vascular environment, modified lipids and other cellular exchanges. There is a particular focus on monocytes and macrophages, but shorter descriptions of dendritic cells, lymphocyte populations, neutrophils, mast cells and platelets are also included.

  2. Strategic Aspects of Communication

    NASA Astrophysics Data System (ADS)

    Hagen, Edward; Hammerstein, Peter; Hess, Nicole

    Rarely do human behavioral scientists and scholars study language, music, and other forms of communication as strategies—a means to some end. Some even deny that communication is the primary function of these phenomena. Here we draw upon selections of our earlier work to briefly define the strategy concept and sketch how decision theory, developed to explain the behavior of rational actors, is applied to evolved agents. Communication can then be interpreted as a strategy that advances the "fitness interests" of such agents. When this perspective is applied to agents with conflicts of interest, deception emerges as an important aspect of communication. We briefly review costly signaling, one solution to the problem of honest communication among agents with conflicts of interest. We also explore the subversion of cooperative signals by parasites and by plants defending themselves against herbivores, and we touch on biases in human gossip. Experiments with artificial embodied and communicating agents confirm that when there are conflicts of interest among agents, deception readily evolves. Finally, we consider signaling among super-organisms and the possible implications for understanding human music and language.

  3. Aspects of cosmological relativity.

    NASA Astrophysics Data System (ADS)

    Carmeli, M.

    1999-07-01

    The author reviews cosmological relativity, a new special theory of relativity that was recently developed for cosmology, and discusses in detail some of its aspects. He recalls that in this theory it is assumed that gravitation is negligible. Under this assumption, the receding velocities of galaxies and the distances between them in the Hubble expansion are united into a four-dimensional pseudo-Euclidean manifold, similarly to space and time in ordinary special relativity. The Hubble law is assumed and is written in an invariant way that enables one to derive a four-dimensional transformation which is similar to the Lorentz transformation. The parameter in the new transformation is the ratio between the cosmic time to the Hubble time. Accordingly, the new transformation relates physical quantities at different cosmic times in the limit of weak or negligible gravitation. The transformation is then applied to the problem of the expansion of the universe at the very early stage when gravity was negligible and thus the transformation is applicable. New applications of the theory are presented. The author shows that there is no need to assume the existence of galaxy dark matter; the Tully-Fisher law is derived from the theory. A completely new picture of the expanding universe is thus obtained and compared to the FRW one.

  4. Cultural aspects of suicide.

    PubMed

    Maharajh, Hari D; Abdool, Petal S

    2005-09-08

    Undefined cultural factors cannot be dismissed and significantly contribute to the worldwide incidence of death by suicide. Culture is an all embracing term and defines the relationship of an individual to his environment. This study seeks to investigate the effect of culture on suicide both regionally and internationally. Culture-bound syndrome with suicidal behaviours specific to a particular culture or geographical region are discussed. Opinions are divided as to the status of religious martyrs. The law itself is silent on many aspects of suicidal behaviour and despite decriminalization of suicide as self-murder, the latter remains on the statutes of many developing countries. The Caribbean region is of concern due to its steady rise in mean suicide rate, especially in Trinidad and Tobago where socio-cultural factors are instrumental in influencing suicidal behaviour. These include transgenerational cultural conflicts, psycho-social problems, media exposure, unemployment, social distress, religion and family structure. The methods used are attributed to accessibility and lethality. Ingestion of poisonous substances is most popular followed by hanging. The gender differences seen with regard to suicidality can also be attributed to gender related psychopathology and psychosocial differences in help-seeking behaviour. These are influenced by the cultural environment to which the individual is exposed. Culture provides coping strategies to individuals; as civilization advances many of these coping mechanisms are lost unclothing the genetic predisposition of vulnerable groups. In the management of suicidal behaviour, a system of therapeutic re-culturation is needed with an emphasis on relevant culture- based therapies.

  5. Electrical aspects of rainout

    SciTech Connect

    Rosenkilde, C.E.

    1981-11-23

    Rainout commonly denotes the aggregate of phenomena associated with precipitation scavenging of radioactivity from a cloud of nuclear debris that is within a natural rain cloud. (In contrast, the term, washout, is applicable when the nuclear cloud is below the rain cloud and the term, fallout, commonly denotes the direct gravitational settling of contaminated solid material from a nuclear cloud.) Nuclear debris aerosols may be scavenged within natural clouds by a variety of different physical processes which may involve diffusion, convection, impaction, nucleation, phoresis, turbulence, and/or electricity among others. Processes which involve electrical aspects are scrutinized for their susceptibility to the intimate presence of the radioactive-cloud environment. This particular choice of electrical processes is not accidental. Nearly all of the listed processes were examined earlier by Williams. His rough estimates suggested that electrical effects, and to a lesser extent turbulence, could enhance the scavenging of those submicron aerosols which reside in the size-range that bridges the minimum in the scavenging rate coefficient which is commonly called the Greenfield gap. This minimum in the scavenging-rate coefficient is created by the simultaneous reduction of scavenging via diffusion and the reduction of scavenging via inertial impaction. However, Williams omitted the specific influence of a radioactive environment. This report aims to remedy this omission.

  6. [Affective dependency].

    PubMed

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.

  7. Implementing Subduction Models in the New Mantle Convection Code Aspect

    NASA Astrophysics Data System (ADS)

    Arredondo, Katrina; Billen, Magali

    2014-05-01

    The geodynamic community has utilized various numerical modeling codes as scientific questions arise and computer processing power increases. Citcom, a widely used mantle convection code, has limitations and vulnerabilities such as temperature overshoots of hundreds or thousands degrees Kelvin (i.e., Kommu et al., 2013). Recently Aspect intended as a more powerful cousin, is in active development with additions such as Adaptable Mesh Refinement (AMR) and improved solvers (Kronbichler et al., 2012). The validity and ease of use of Aspect is important to its survival and role as a possible upgrade and replacement to Citcom. Development of publishable models illustrates the capacity of Aspect. We present work on the addition of non-linear solvers and stress-dependent rheology to Aspect. With a solid foundational knowledge of C++, these additions were easily added into Aspect and tested against CitcomS. Time-dependent subduction models akin to those in Billen and Hirth (2007) are built and compared in CitcomS and Aspect. Comparison with CitcomS assists in Aspect development and showcases its flexibility, usability and capabilities. References: Billen, M. I., and G. Hirth, 2007. Rheologic controls on slab dynamics. Geochemistry, Geophysics, Geosystems. Kommu, R., E. Heien, L. H. Kellogg, W. Bangerth, T. Heister, E. Studley, 2013. The Overshoot Phenomenon in Geodynamics Codes. American Geophysical Union Fall Meeting. M. Kronbichler, T. Heister, W. Bangerth, 2012, High Accuracy Mantle Convection Simulation through Modern Numerical Methods, Geophys. J. Int.

  8. Emotional aspects of hyperprolactinemia.

    PubMed

    Sobrinho, L G

    1998-01-01

    Patients with hyperprolactinemia often present with emotional difficulties. These occasionally persist even after successful treatment. Insight into the roots of their diseased state makes a difference in the handling of all cases, but becomes crucial in the not-so-rare situations in which the normalization of hormonal levels is not followed by a feeling of cure. This chapter attempts to provide details, discuss and situate in context the following blocks of pertinent information: (1) prolactin acts upon the central nervous system and variations in its concentrations do affect mood, emotions and behavior; (2) most actions of prolactin are directed to metabolical and behavioral adaptation to pregnancy and the care of the young; (3) even in the absence of pregnancy prolactin secretion responds to environmental stimuli under specific conditions. Whether adaptive, as in the case of surrogate maternity, or pathological, as in the case of pseudopregnancy, prolactin responds to a perceived need to take care of a child; (4) the facts that the clinical onset of prolactinomas often follows life-events and that these tumors occur preferentially in women brought up under specific conditions suggest the possibility that psychological factors may predispose to prolactinomas; (5) dealing with individual cases requires the perception that the relations between prolactin, emotions and feelings are circular, i.e., prolactin affects the brain and mood but, on the other hand, personality traits and environmental factors may stimulate the secretion of prolactin and may play a role in the genesis of the disease.

  9. Historical aspects of dermatomycoses.

    PubMed

    Negroni, Ricardo

    2010-03-04

    Physicians have been aware of superficial fungal infections for centuries, but the causal agents and treatments of fungal infections remained unknown until the mid-1800s, when numerous important findings were reported. Among the relevant researchers in the field of superficial mycoses were Remak, who found the fungal nature of favus in 1837; Berg, who reported oral candidosis in 1841; and Wilkinson, who described vaginal candidosis in 1849. Tinea versicolor was described clinically in 1846 by Eichstedt, and its etiologic agent was identified in 1853. Beigel reported white piedra in 1856, and Cerqueira, tinea nigra in 1891. The book Les Tiegnes was published by Sabouraud in 1910, and black piedra infection was described by Horta in 1911. In 1927, Nannizzi reported the description of the sexual state of Microsporum gypseum. The current classification of dermatophytes was published by Emmons in 1934, and the taxonomy of yeast fungi was described by Lodder and Kreger-van Rij in 1952. Finally, the successful treatment of tinea capitis with griseofulvin by Gentles in 1958 saved many patients with tinea capitis from permanent hair loss, a common side effect after treatment with thallium. (c) 2010 Elsevier Inc. All rights reserved.

  10. International trade. Multinational aspects.

    PubMed

    Ozawa, Y

    2000-01-01

    Of numerous regional economic agreements, the European Union (EU), the North American Free Trade Agreement (NAFTA), South American Common Market (MERCOSUR), the Association of Southeast Asian Nations (ASEAN), the South Asian Association for Regional Cooperation (SAARC) and the Australia-New Zealand Closer Economic Relations Agreement are examples that are actively pursuing regional integration for freer trade of animals and animal products. The World Trade Organization (WTO) believes that regional and multinational integration initiatives are complements rather than alternatives in the pursuit of more open trade. In the efforts to harmonize SPS standards among multilateral trading nations, it is recommended that national requirements meet the standards developed by the OIE and the FAO/WHO Codex Alimentarius Commission as the minimum requirements rather than adopting the standards of the lowest common denominator. Regional grouping may hinder multilateral or bilateral trade between the countries of a group and those of the other groups. How to eliminate such non-tariff barriers as traditional trade custom remains to be examined. Ongoing activities of VICH (Harmonisation of Technical Requirements for Registration of Veterinary Medical Products) may pave the way for more open trade in pharmaceutical products between multilateral regional groups.

  11. Psychological aspects of asthma.

    PubMed

    Lehrer, Paul; Feldman, Jonathan; Giardino, Nicholas; Song, Hye-Sue; Schmaling, Karen

    2002-06-01

    Asthma can be affected by stress, anxiety, sadness, and suggestion, as well as by environmental irritants or allergens, exercise, and infection. It also is associated with an elevated prevalence of anxiety and depressive disorders. Asthma and these psychological states and traits may mutually potentiate each other through direct psychophysiological mediation, nonadherence to medical regimen, exposure to asthma triggers, and inaccuracy of asthma symptom perception. Defensiveness is associated with inaccurate perception of airway resistance and stress-related bronchoconstriction. Asthma education programs that teach about the nature of the disease, medications, and trigger avoidance tend to reduce asthma morbidity. Other promising psychological interventions as adjuncts to medical treatment include training in symptom perception, stress management, hypnosis, yoga, and several biofeedback procedures.

  12. Numerical orbit generators of artificial earth satellites

    NASA Astrophysics Data System (ADS)

    Kugar, H. K.; Dasilva, W. C. C.

    1984-04-01

    A numerical orbit integrator containing updatings and improvements relative to the previous ones that are being utilized by the Departmento de Mecanica Espacial e Controle (DMC), of INPE, besides incorporating newer modellings resulting from the skill acquired along the time is presented. Flexibility and modularity were taken into account in order to allow future extensions and modifications. Characteristics of numerical accuracy, processing quickness, memory saving as well as utilization aspects were also considered. User's handbook, whole program listing and qualitative analysis of accuracy, processing time and orbit perturbation effects were included as well.

  13. Omniclassical Diffusion in Low Aspect Ratio Tokamaks

    SciTech Connect

    H.E. Mynick; R.B. White; D.A. Gates

    2004-03-19

    Recently reported numerical results for axisymmetric devices with low aspect ratio A found radial transport enhanced over the expected neoclassical value by a factor of 2 to 3. In this paper, we provide an explanation for this enhancement. Transport theory in toroidal devices usually assumes large A, and that the ratio B{sub p}/B{sub t} of the poloidal to the toroidal magnetic field is small. These assumptions result in transport which, in the low collision limit, is dominated by banana orbits, giving the largest collisionless excursion of a particle from an initial flux surface. However in a small aspect ratio device one may have B{sub p}/B{sub t} {approx} 1, and the gyroradius may be larger than the banana excursion. Here, we develop an approximate analytic transport theory valid for devices with arbitrary A. For low A, we find that the enhanced transport, referred to as omniclassical, is a combination of neoclassical and properly generalized classical effects, which become dominant in the low-A, B{sub p}/B{sub t} {approx} 1 regime. Good agreement of the analytic theory with numerical simulations is obtained.

  14. Climate-ecosystem change off southern California: Time-dependent seabird predator-prey numerical responses

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Thompson, Sarah Ann; Santora, Jarrod A.; Koslow, J. Anthony; Goericke, Ralf; Ohman, Mark D.

    2015-02-01

    Climate change may increase both stratification and upwelling in marine ecosystems, but these processes may affect productivity in opposing or complementary ways. For the Southern California region of the California Current Ecosystem (CCE), we hypothesized that changes in stratification and upwelling have affected marine bird populations indirectly through changes in prey availability. To test this hypothesis, we derived trends and associations between stratification and upwelling, the relative abundance of potential prey including krill and forage fish, and seabirds based on the long-term, multi-disciplinary CalCOFI/CCE-LTER program. Over the period 1987 through 2011, spring and summer seabird density (all species combined) declined by ~2% per year, mostly in the northern sector of the study region. Krill showed variable trends with two species increasing and one deceasing, resulting in community reorganization. Nearshore forage fish, dominated by northern anchovy (Engraulis mordax) as well as offshore mesopelagic species, show declines in relative abundance over this period. The unidirectional decline in springtime seabird density is largely explained by declining nearshore fish abundance in the previous season (winter). Interannual variability in seabird density, especially in the 2000s, is explained by variability in krill abundance. Changes in the numerical responses of seabirds to prey abundance correspond to a putative ecosystem shift in 1998-1999 and support aspects of optimal foraging (diet) theory. Predator-prey interactions and numerical responses clearly explain aspects of the upper trophic level patterns of change in the pelagic ecosystem off southern California.

  15. Aspects of flux compactification

    NASA Astrophysics Data System (ADS)

    Liu, Tao

    In this thesis, we study three main aspects of flux compactifications: (1) classify supergravity solutions from flux compactification; (2) construct flux-deformed geometry and 4D low-energy theory to describe these flux vacua; and (3) study 4D particle phenomenology and cosmology of flux vacua. In the first part, we review G-structure, the basic tool to study supersymmetric flux solutions, and some typical solutions obtained in heterotic, type IIA and type IIB string theories. Then we present a comprehensive classification of supersymmetric vacua of M-theory compactification on 7D manifolds with general four-form fluxes. We analyze the cases where the resulting four-dimensional vacua have N = 1, 2, 3, 4 supersymmetry and the internal space allows for SU(2)-, SU(3)- or G 2-structures. In particular, we find for N = 2 supersymmetry, that the external space-time is Minkowski and the base manifold of the internal space is conformally Kahler for SU(2) structures, while for SU(3) structures the internal space has to be Einstein-Sasaki and no internal fluxes are allowed. Moreover, we provide a new vacuum with N = 1 supersymmetry and SU(3) structure, where all fluxes are non-zero and the first order differential equations are solved. In the second part, we simply review the methods used to construct one subclass of fluxed-deformed geometry or the so-called "twisted manifold", and the associated 4D effective theory describing these flux vacua. Then by employing (generalized) Scherk-Schwarz reduction, we construct the geometric twisting for Calabi-Yau manifolds of Voisin-Borcea type (K 3 x T2)/ Z2 and study the superpotential in a type IIA orientifold based on this geometry. The twists modify the direct product by fibering the K 3 over T2 while preserving the Z2 involution. As an important application, the Voisin-Borcea class contains T6/( Z2 x Z2 ), the usual setting for intersecting D6 brane model building. Past work in this context considered only those twists inherited

  16. What Is Numerical Control?

    ERIC Educational Resources Information Center

    Goold, Vernell C.

    1977-01-01

    Numerical control (a technique involving coded, numerical instructions for the automatic control and performance of a machine tool) does not replace fundamental machine tool training. It should be added to the training program to give the student an additional tool to accomplish production rates and accuracy that were not possible before. (HD)

  17. [Arteriosclerosis--selected aspects].

    PubMed

    Kucharska, Ewa

    2014-01-01

    The article summarizes the current knowledge concerning the diagnosis of atherosclerosis and therapeutic objectives. Atherosclerosis is one of the most common medical problems. It affects adults as well as children. It leads to clinically overt cardiovascular diseases (CVD), which are the cause of premature deaths. During its course, the formation of atherosclerotic plaque takes place, along with local inflammations artery walls. Gradually growing plaque does not cause clinical symptoms until the stenosis does not exceed 70-80% of the coronary vessel diameter, causing a marked reduction in blood flow to the heart muscle. The prevention of atherosclerosis and its complications requires an individual assessment of cardiovascular risk. In people without CVD symptoms, it is recommended to use SCORE risk card for Polish population, assessing the 10-year risk of cardiac death. A key element in combating atherosclerosis is to eliminate its risk factors by both implementing pro-health policies, as well as working with individual patients. An important objective is the proper control of blood pressure. It should not exceed 140/90 mmHg. A very important role is played by correct approach to patients with moderate or unusual cardiovascular risk. Despite knowing many facts about the mechanisms of atherosclerosis and its treatment, many issues still remain to be clarified. Finding methods to influence ongoing immune processes within arteries is of particular interest, which will soon make way to new therapeutic possibilities.

  18. Obesity: epigenetic aspects.

    PubMed

    Kaushik, Prashant; Anderson, James T

    2016-06-01

    Epigenetics, defined as inheritable and reversible phenomena that affect gene expression without altering the underlying base pair sequence has been shown to play an important role in the etiopathogenesis of obesity. Obesity is associated with extensive gene expression changes in tissues throughout the body. Epigenetics is emerging as perhaps the most important mechanism through which the lifestyle-choices we make can directly influence the genome. Considerable epidemiological, experimental and clinical data have been amassed showing that the risk of developing disease in later life is dependent on early life conditions, mainly operating within the normative range of developmental exposures. In addition to the 'maternal' interactions, there has been increasing interest in the epigenetic mechanisms through which 'paternal' influences on offspring development can be achieved. Nutrition, among many other environmental factors, is a key player that can induce epigenetic changes not only in the directly exposed organisms but also in subsequent generations through the transgenerational inheritance of epigenetic traits. Overall, significant progress has been made in the field of epigenetics and obesity and the first potential epigenetic markers for obesity that could be detected at birth have been identified. Fortunately, epigenetic phenomena are dynamic and rather quickly reversible with intensive lifestyle changes. This is a very promising and sustainable resolution to the obesity pandemic.

  19. Pharmacotherapeutic Aspects of Space Medicine

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi

    2004-01-01

    produced by any drug depend upon rates of absorption, distribution, metabolism, and elimination of the drug; space flight-induced changes in blood flow and the function of the gastrointestinal (GI) tract, liver, or kidneys may alter these processes. Another important aspect of clinical efficacy of medications in space is the stability of pharmaceuticals. As the U.S. space program is moving toward extended Space Shuttle flights and beyond, to space station missions and planetary explorations, understanding how space flight affects organ systems and clinical pharmacology is necessary to optimize pharmacotherapeutics in space and ensure adequate safety and health of crewmembers.

  20. Numerical micromagnetism of strong inhomogeneities

    NASA Astrophysics Data System (ADS)

    Andreas, Christian; Gliga, Sebastian; Hertel, Riccardo

    2014-08-01

    The size of micromagnetic structures, such as domain walls or vortices, is comparable to the exchange length of the ferromagnet. Both, the exchange length of the stray field ls and the magnetocrystalline exchange length lk, are material-dependent quantities that usually lie in the nanometer range. This emphasizes the theoretical challenges associated with the mesoscopic nature of micromagnetism: the magnetic structures are much larger than the atomic lattice constant, but at the same time much smaller than the sample size. In computer simulations, the smallest exchange length serves as an estimate for the largest cell size admissible to prevent appreciable discretization errors. This general rule is not valid in special situations where the magnetization becomes particularly inhomogeneous. When such strongly inhomogeneous structures develop, micromagnetic simulations inevitably contain systematic and numerical errors. It is suggested to combine micromagnetic theory with a Heisenberg model to resolve such problems. We analyze cases where strongly inhomogeneous structures pose limits to standard micromagnetic simulations, arising from fundamental aspects as well as from numerical drawbacks.

  1. Clinical aspects of telemedicine

    NASA Technical Reports Server (NTRS)

    Merrell, Ronald C.

    1991-01-01

    Communication among physicians is an essential in order to combine our experiences for the elucidation and application of new knowledge and for the accurate and uniform application of established medical practice. This communication requires an adequate understanding of the culture of the patient and the social context of disease and indeed the culture of the physician. Malnutrition in Bangladesh means caloric insufficiency, and a program to lower cholesterol would be impertinent, while a program to enhance the nutrition of patients in Texas by an international effort to import more grain would be ludicrous. In the same vein a public health effort to combat alcoholic cirrhosis in Mecca would be as silly as a program to increase fiber in the diet of the Bantu. Clinical communication must acknowledge the culture of the issue at hand and the differences in the experiential base of the physicians. Not only do geography and culture affect the potential differences in the experiential bases, but the world utilizes very different traditions of education and science in training physicians. We are influenced by the diseases we treat, and learn to look for the expected at least as much as we are attentive to the unexpected. A physician in Siberia would be much more likely to recognize frostbite than one from Buenos Aires, and the Argentine doctor would much more likely consider Chaga's Disease to explain abdominal pain than a colleague in Zurich. Beyond these obvious issues in communication among physicians we must deal with the many languages and idioms used in the world. An overview of using Telemedicine SpaceBridge after the earthquake in the Republic of Armenia in 1988 is presented.

  2. Aspect ratio effect on particle transport in turbulent duct flows

    NASA Astrophysics Data System (ADS)

    Noorani, A.; Vinuesa, R.; Brandt, L.; Schlatter, P.

    2016-11-01

    The dynamics of dilute micron-sized spherical inertial particles in turbulent duct flows is studied by means of direct numerical simulations of the carrier phase turbulence with one-way coupled Lagrangian particles. The geometries are a square and a rectangular duct with width-to-height aspect ratio AR of 3 operating at Reτ,c = 360 (based on the centerplane friction velocity and duct half-height). The present study is designed to determine the effect of turbulence-driven secondary motion on the particle dynamics. Our results show that a weak cross-flow secondary motion significantly changes the cross-sectional map of the particle concentration, mean velocity, and fluctuations. As the geometry of the duct is widened from AR = 1 to 3, the secondary vortex on the horizontal wall significantly expands in the spanwise direction, and although the kinetic energy of the secondary flow increases close to the corner, it decays towards the duct centreplane in the AR = 3 case so as the turbulent carrier phase approaches the behavior in spanwise-periodic channel flows, a fact that significantly affects the particle statistics. In the square duct the particle concentration in the viscous sublayer is maximum at the duct centreplane, whereas the maximum is found closer to the corner, at a distance of |z/h| ≈ 1.25 from the centreplane, in the AR = 3 case. Interestingly the centreplane concentration in the rectangular duct is around 3 times lower than that in the square duct. Moreover, a second peak in the accumulation distribution is found right at the corners for both ducts. At this location the concentration increases with particle inertia. The secondary motion changes also the cross-stream map of the particle velocities significantly in comparison to the fluid flow statistics. These directly affect the particle velocity fluctuations such that multiple peaks appear near the duct walls for the particle streamwise and wall-normal velocity fluctuations.

  3. Stability Affects of Artificial Viscosity in Detonation Modeling

    SciTech Connect

    Vitello, P; Souers, P C

    2002-06-03

    Accurate multi-dimensional modeling of detonation waves in solid HE materials is a difficult task. To treat applied problems which contain detonation waves one must consider reacting flow with a wide range of length-scales, non-linear equations of state (EOS), and material interfaces at which the detonation wave interacts with other materials. To be useful numerical models of detonation waves must be accurate, stable, and insensitive to details of the modeling such as the mesh spacing, and mesh aspect ratio for multi-dimensional simulations. Studies we have performed show that numerical simulations of detonation waves can be very sensitive to the form of the artificial viscosity term used. The artificial viscosity term is included in our ALE hydrocode to treat shock discontinuities. We show that a monotonic, second order artificial viscosity model derived from an approximate Riemann solver scheme can strongly damp unphysical oscillations in the detonation wave reaction zone, improving the detonation wave boundary wall interaction. These issues are demonstrated in 2D model simulations presented of the 'Bigplate' test. Results using LX-I 7 explosives are compared with numerical simulation results to demonstrate the affects of the artificial viscosity model.

  4. Robots in Space -Psychological Aspects

    NASA Technical Reports Server (NTRS)

    Sipes, Walter E.

    2006-01-01

    A viewgraph presentation on the psychological aspects of developing robots to perform routine operations associated with monitoring, inspection, maintenance and repair in space is shown. The topics include: 1) Purpose; 2) Vision; 3) Current Robots in Space; 4) Ground Based Robots; 5) AERCam; 6) Rotating Bladder Robot (ROBLR); 7) DART; 8) Robonaut; 9) Full Immersion Telepresence Testbed; 10) ERA; and 11) Psychological Aspects

  5. Theoretical aspects of calcium signaling

    NASA Astrophysics Data System (ADS)

    Pencea, Corneliu Stefan

    2001-08-01

    Experiments investigating intracellular calcium dynamics have revealed that calcium signals differentially affect a variety of intracellular processes, from fertilization and cell development and differentiation to subsequent cellular activity, ending with cell death. As an intracellular messenger, calcium transmits information within and between cells, thus regulating their activity. To control such a variety of processes, calcium signals have to be very flexible and also precisely regulated. The cell uses a calcium signaling ``toolkit'', where calcium ions can act in different contexts of space, amplitude and time. For different tasks, the cell selects the particular signal, or combination of signals, that triggers the appropriate physiological response. The physical foundations of such a versatile cellular signaling toolkit involving calcium are not completely understood, despite important experimental and theoretical progress made recently. The declared goal of this work is to investigate physical mechanisms on which the propagation of differential signals can be based. The dynamics of calcium near a cluster of inositol trisphosphate (IP3) activated calcium channels has been investigated analytically and numerically. Our work has demonstrated that clusters of different IP3 receptors can show similar bistable behavior, but differ in both the transient and long term dynamics. We have also investigated the conditions under which a calcium signal propagates between a pair of localized stores. We have shown that the propagation of the signal across a random distribution of such stores shows a percolation transition manifested in the shape of the wave front. More importantly, our work indicates that specific distribution of stores can be interpreted as calcium circuits that can perform important signal analyzing task, from unidirectional propagation and coincidence detection to a complete set of logic gates. We believe that phenomena like the ones described are

  6. Biotechnological aspects of plum pox virus.

    PubMed

    López-Moya, J J; Fernández-Fernández, M R; Cambra, M; García, J A

    2000-01-21

    Plum pox potyvirus (PPV), the causal agent of a devastating disease that affects stone fruit trees, is becoming a target of intense studies intended both to fight against viral infection and to develop practical applications based on the current knowledge of potyvirus molecular biology. This review focuses on biotechnological aspects related to PPV, such as novel diagnostic techniques that facilitate detection and typing of virus isolates, strategies to implement pathogen-derived resistance through plant transformation, the potential use of genetic elements derived from the virus, and the recent development of PPV-based expression vectors.

  7. Otherness within: aspects of insight in psychoanalysis.

    PubMed

    Wilson, M

    1998-01-01

    In this paper I consider moments of insight in which the subject consciously experiences the emergence of something alien within the self, usually of a drive-related, affective, and at times uncanny nature. These are crucial, yet neglected, experiences of insight within the therapeutic process. Such experiences do not fit easily into our theory, because usual descriptions of insight stress the ego's integrative capacities. I attempt to demonstrate how aspects of our theory that emphasize rational, narrative explanations, or the social construction of clinical facts, as well as those that emphasize the ego's integrative functions, may prevent our fully appreciating these experiences of insight in our patients.

  8. Rocket engine numerical simulation

    NASA Technical Reports Server (NTRS)

    Davidian, Ken

    1993-01-01

    The topics are presented in view graph form and include the following: a definition of the rocket engine numerical simulator (RENS); objectives; justification; approach; potential applications; potential users; RENS work flowchart; RENS prototype; and conclusions.

  9. Rocket engine numerical simulator

    NASA Technical Reports Server (NTRS)

    Davidian, Ken

    1993-01-01

    The topics are presented in viewgraph form and include the following: a rocket engine numerical simulator (RENS) definition; objectives; justification; approach; potential applications; potential users; RENS work flowchart; RENS prototype; and conclusion.

  10. Numerical Techniques in Acoustics

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J. (Compiler)

    1985-01-01

    This is the compilation of abstracts of the Numerical Techniques in Acoustics Forum held at the ASME's Winter Annual Meeting. This forum was for informal presentation and information exchange of ongoing acoustic work in finite elements, finite difference, boundary elements and other numerical approaches. As part of this forum, it was intended to allow the participants time to raise questions on unresolved problems and to generate discussions on possible approaches and methods of solution.

  11. Aspect-Oriented Design with Reusable Aspect Models

    NASA Astrophysics Data System (ADS)

    Kienzle, Jörg; Al Abed, Wisam; Fleurey, Franck; Jézéquel, Jean-Marc; Klein, Jacques

    The idea behind Aspect-Oriented Modeling (AOM) is to apply aspect-oriented techniques to (software) models with the aim of modularizing crosscutting concerns. This can be done within different modeling notations, at different levels of abstraction, and at different moments during the software development process. This paper demonstrates the applicability of AOM during the software design phase by presenting parts of an aspect-oriented design of a crisis management system. The design solution proposed in this paper is based on the Reusable Aspect Models (RAM) approach, which allows a modeler to express the structure and behavior of a complex system using class, state and sequence diagrams encapsulated in several aspect models. The paper describes how the model of the "create mission" functionality of the server backend can be decomposed into 23 inter-dependent aspect models. The presentation of the design is followed by a discussion on the lessons learned from the case study. Next, RAM is compared to 8 other AOM approaches according to 6 criteria: language, concern composition, asymmetric and symmetric composition, maturity, and tool support. To conclude the paper, a discussion section points out the features of RAM that specifically support reuse.

  12. Frontiers in Numerical Relativity

    NASA Astrophysics Data System (ADS)

    Evans, Charles R.; Finn, Lee S.; Hobill, David W.

    2011-06-01

    Preface; Participants; Introduction; 1. Supercomputing and numerical relativity: a look at the past, present and future David W. Hobill and Larry L. Smarr; 2. Computational relativity in two and three dimensions Stuart L. Shapiro and Saul A. Teukolsky; 3. Slowly moving maximally charged black holes Robert C. Ferrell and Douglas M. Eardley; 4. Kepler's third law in general relativity Steven Detweiler; 5. Black hole spacetimes: testing numerical relativity David H. Bernstein, David W. Hobill and Larry L. Smarr; 6. Three dimensional initial data of numerical relativity Ken-ichi Oohara and Takashi Nakamura; 7. Initial data for collisions of black holes and other gravitational miscellany James W. York, Jr.; 8. Analytic-numerical matching for gravitational waveform extraction Andrew M. Abrahams; 9. Supernovae, gravitational radiation and the quadrupole formula L. S. Finn; 10. Gravitational radiation from perturbations of stellar core collapse models Edward Seidel and Thomas Moore; 11. General relativistic implicit radiation hydrodynamics in polar sliced space-time Paul J. Schinder; 12. General relativistic radiation hydrodynamics in spherically symmetric spacetimes A. Mezzacappa and R. A. Matzner; 13. Constraint preserving transport for magnetohydrodynamics John F. Hawley and Charles R. Evans; 14. Enforcing the momentum constraints during axisymmetric spacelike simulations Charles R. Evans; 15. Experiences with an adaptive mesh refinement algorithm in numerical relativity Matthew W. Choptuik; 16. The multigrid technique Gregory B. Cook; 17. Finite element methods in numerical relativity P. J. Mann; 18. Pseudo-spectral methods applied to gravitational collapse Silvano Bonazzola and Jean-Alain Marck; 19. Methods in 3D numerical relativity Takashi Nakamura and Ken-ichi Oohara; 20. Nonaxisymmetric rotating gravitational collapse and gravitational radiation Richard F. Stark; 21. Nonaxisymmetric neutron star collisions: initial results using smooth particle hydrodynamics

  13. Sexual Aspects of Multilateral Relations

    ERIC Educational Resources Information Center

    Constantine, Joan M.; Constantine, Larry L.

    1971-01-01

    This study involved a variety of data gathering techniques focusing on almost every aspect of multilateral marriages. Specific topics covered included sex as motivation, group sex, sleeping arrangements, cohesion, sexual problems, jealousy, roles and sex differences. (Author/CG)

  14. Administrative Aspects of Human Experimentation.

    ERIC Educational Resources Information Center

    Irvine, George W.

    1992-01-01

    The following administrative aspects of scientific experimentation with human subjects are discussed: the definition of human experimentation; the distinction between experimentation and treatment; investigator responsibility; documentation; the elements and principles of informed consent; and the administrator's role in establishing and…

  15. Topological Aspects of Information Retrieval.

    ERIC Educational Resources Information Center

    Egghe, Leo; Rousseau, Ronald

    1998-01-01

    Discusses topological aspects of theoretical information retrieval, including retrieval topology; similarity topology; pseudo-metric topology; document spaces as topological spaces; Boolean information retrieval as a subsystem of any topological system; and proofs of theorems. (LRW)

  16. A Digital Solar Aspect Sensor

    NASA Technical Reports Server (NTRS)

    Albus, James S.

    1961-01-01

    The solar aspect sensor described herein performs the analog-to-digital conversion of data optically. To accomplish this, it uses a binary "Gray code" light mask to produce a digital indication, in vehicle-fixed coordinates, of the elevation and azimuth angles of incident light from the sun. This digital solar aspect sensor system, in Explorer X, provided measurements of both elevation and azimuth angles to +/- 2 degrees at a distance of over 140,000 statute miles.

  17. Magnitude knowledge: the common core of numerical development.

    PubMed

    Siegler, Robert S

    2016-05-01

    The integrated theory of numerical development posits that a central theme of numerical development from infancy to adulthood is progressive broadening of the types and ranges of numbers whose magnitudes are accurately represented. The process includes four overlapping trends: (1) representing increasingly precisely the magnitudes of non-symbolic numbers, (2) connecting small symbolic numbers to their non-symbolic referents, (3) extending understanding from smaller to larger whole numbers, and (4) accurately representing the magnitudes of rational numbers. The present review identifies substantial commonalities, as well as differences, in these four aspects of numerical development. With both whole and rational numbers, numerical magnitude knowledge is concurrently correlated with, longitudinally predictive of, and causally related to multiple aspects of mathematical understanding, including arithmetic and overall math achievement. Moreover, interventions focused on increasing numerical magnitude knowledge often generalize to other aspects of mathematics. The cognitive processes of association and analogy seem to play especially large roles in this development. Thus, acquisition of numerical magnitude knowledge can be seen as the common core of numerical development.

  18. Winglets on low aspect ratio wings

    NASA Technical Reports Server (NTRS)

    Kuhlman, John M.; Liaw, Paul

    1987-01-01

    The drag reduction potentially available from the use of winglets at the tips of low aspect ratio (1.75-2.67) wings with pronounced (45-60 deg) leading edge sweep is assessed numerically for the case of a cruise design point at Mach of 0.8 and a lift coefficient of 0.3. Both wing-winglet and wing-alone design geometries are derived from a linear-theory, minimum induced drag design methodology. Relative performance is evaluated with a nonlinear extended small disturbance potential flow analysis code. Predicted lift coefficient/pressure drag coefficient increases at equal lift for the wing-winglet configurations over the wing-alone planform are of the order of 14.6-15.8, when boundary layer interaction is included.

  19. [Molecular Pathological Aspects in Visceral Surgery].

    PubMed

    Unger, T; Sändig, I; Wittekind, C

    2016-04-01

    New insights gained in the field of molecular medicine have led to fundamental progress in the diagnosis and treatment of tumour patients. Individualised treatment has been essentially facilitated by molecular diagnostics, which, by identifying and interpreting characteristic genetic alterations (biomarkers) in single cells and tissues, provide specific information to confirm the diagnosis and support the treatment of numerous diseases. Particularly with regard to the use of new targeted drugs, which often require the presence or absence of specific target structures or genetic alterations to induce response, the molecular pathological determination of predictive biomarkers plays an increasing role and helps clinicians to decide on optimal therapies for individual patients. The aim of this review is to highlight general aspects of molecular tumour pathology for relevant tumour entities and to present available targeted therapies.

  20. Numerical Investigation of Boiling

    NASA Astrophysics Data System (ADS)

    Sagan, Michael; Tanguy, Sebastien; Colin, Catherine

    2012-11-01

    In this work, boiling is numerically investigated, using two phase flow direct numerical simulation based on a level set / Ghost Fluid method. Nucleate boiling implies both thermal issue and multiphase dynamics issues at different scales and at different stages of bubble growth. As a result, the different phenomena are investigated separately, considering their nature and the scale at which they occur. First, boiling of a static bubble immersed in an overheated liquid is analysed. Numerical simulations have been performed at different Jakob numbers in the case of strong density discontinuity through the interface. The results show a good agreement on bubble radius evolution between the theoretical evolution and numerical simulation. After the validation of the code for the Scriven test case, interaction of a bubble with a wall is studied. A numerical method taking into account contact angle is evaluated by comparing simulations of the spreading of a liquid droplet impacting on a plate, with experimental data. Then the heat transfer near the contact line is investigated, and simulations of nucleate boiling are performed considering different contact angles values. Finally, the relevance of including a model to take into account the evaporation of the micro layer is discussed.

  1. Multicultural Aspects in Functional Gastrointestinal Disorders (FGIDs).

    PubMed

    Fang, Xiucai; Francisconi, Carlos F; Fukudo, Shin; Gerson, Mary-Joan; Kang, Jin-Yong; Schmulson W, Max J; Sperber, Ami D

    2016-02-15

    Cross-cultural factors are important in functional gastrointestinal disorders (FGIDs). In the setting of FGIDs, the aims of this review were to: 1) engender interest in global aspects; 2) gain a clearer understanding of culture, race and ethnicity and their effect on patient care and research; 3) facilitate cross-cultural clinical and research competency; and 4) improve and foster the quality and conduct of cross-cultural, multinational research. Cultural variables are inevitably present in the physician-patient context. Food and diets, which differ among cultural groups, are perceived globally as related to or blamed for symptoms. From an individual perspective, biological aspects, such as genetics, the microbiome, environmental hygiene, cytokines and the nervous system, which are affected by cultural differences, are all relevant. Of equal importance are issues related to gender, symptom reporting and interpretation, and family systems. From the physician's viewpoint, understanding the patient's explanatory model of illness, especially in a cultural context, affects patient care and patient education in a multicultural environment. Differences in the definition and use of Complementary and Alternative Medicine and other issues related to healthcare services for the FGIDs are also a relevant cross-cultural issue. This paper highlights the importance of cross-cultural competence in clinical medicine and research.

  2. Postmenopausal osteoporosis - clinical, biological and histopathological aspects.

    PubMed

    Pavel, Oana Roxana; Popescu, Mihaela; Novac, Liliana; Mogoantă, LaurenŢiu; Pavel, LaurenŢiu Petrişor; Vicaş, Răzvan Marius; Trăistaru, Magdalena Rodica

    2016-01-01

    Osteoporosis is one of the most common disorders in postmenopausal women, affecting the quality of life and increasing the risk for fractures in minor traumas. Changes in the bone microarchitecture causes static changes in the body and affects motility. In this study, we analyzed two groups of women, one with physiological menopause and one with surgically induced menopause. The diagnosis of osteoporosis was suspected based on the clinical symptoms and confirmed by assessing bone mineral density by the dual-energy X-ray absorptiometry (DEXA). Comparing some clinical and biological aspects there was noted that a much higher percentage of women with surgically induced menopause exhibited increases in body mass index, changes in serum lipids, cholesterol, triglycerides, blood glucose, serum calcium, magnesemia and osteocalcin. In contrast, no significant differences were observed in the histopathological aspects of bone tissue examined from these two groups. In all patients, there was identified a significant reduction in the number of osteocytes and osteoblasts, the expansion of haversian channels, reducing the number of trabecular bone in the cancellous bone with wide areola cavities often full of adipose tissue, non-homogenous demineralization of both the compact bone and the cancellous bone, atrophy and even absence of the endosteal, and the presence of multiple microfractures. Our study showed that early surgically induced menopause more intensely alters the lipid, carbohydrate and mineral metabolism, thus favoring the onset of osteoporosis.

  3. Reciprocal Modulation of Cognitive and Emotional Aspects in Pianistic Performances

    PubMed Central

    Higuchi, Marcia K. Kodama; Fornari, José; Del Ben, Cristina M.; Graeff, Frederico G.; Leite, João Pereira

    2011-01-01

    Background High level piano performance requires complex integration of perceptual, motor, cognitive and emotive skills. Observations in psychology and neuroscience studies have suggested reciprocal inhibitory modulation of the cognition by emotion and emotion by cognition. However, it is still unclear how cognitive states may influence the pianistic performance. The aim of the present study is to verify the influence of cognitive and affective attention in the piano performances. Methods and Findings Nine pianists were instructed to play the same piece of music, firstly focusing only on cognitive aspects of musical structure (cognitive performances), and secondly, paying attention solely on affective aspects (affective performances). Audio files from pianistic performances were examined using a computational model that retrieves nine specific musical features (descriptors) – loudness, articulation, brightness, harmonic complexity, event detection, key clarity, mode detection, pulse clarity and repetition. In addition, the number of volunteers' errors in the recording sessions was counted. Comments from pianists about their thoughts during performances were also evaluated. The analyses of audio files throughout musical descriptors indicated that the affective performances have more: agogics, legatos, pianos phrasing, and less perception of event density when compared to the cognitive ones. Error analysis demonstrated that volunteers misplayed more left hand notes in the cognitive performances than in the affective ones. Volunteers also played more wrong notes in affective than in cognitive performances. These results correspond to the volunteers' comments that in the affective performances, the cognitive aspects of piano execution are inhibited, whereas in the cognitive performances, the expressiveness is inhibited. Conclusions Therefore, the present results indicate that attention to the emotional aspects of performance enhances expressiveness, but constrains

  4. MOOCs--Theoretical and Practical Aspects: Comparison of Selected Research Results: Poland, Russia, Ukraine, and Australia

    ERIC Educational Resources Information Center

    Smyrnova-Trybulska, Eugenia; Ogrodzka-Mazur, Ewa; Szafranska-Gajdzica, Anna; Morze, Nataliia; Makhachashvili, Rusudan; Noskova, Tatiana; Pavlova, Tatiana; Yakovleva, Olga; Issa, Tomayess; Issa, Theodora

    2016-01-01

    Many higher education students are interested in MOOCs. At the same time, numerous questions are still without answers: formal aspects of participation in MOOCs, the type of motivation on the part of students for participation in MOOCs, quality of MOOCs, students' opinions about type, structure, contents, communication in MOOCs and other aspects.…

  5. Entropy Splitting and Numerical Dissipation

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Vinokur, M.; Djomehri, M. J.

    1999-01-01

    A rigorous stability estimate for arbitrary order of accuracy of spatial central difference schemes for initial-boundary value problems of nonlinear symmetrizable systems of hyperbolic conservation laws was established recently by Olsson and Oliger (1994) and Olsson (1995) and was applied to the two-dimensional compressible Euler equations for a perfect gas by Gerritsen and Olsson (1996) and Gerritsen (1996). The basic building block in developing the stability estimate is a generalized energy approach based on a special splitting of the flux derivative via a convex entropy function and certain homogeneous properties. Due to some of the unique properties of the compressible Euler equations for a perfect gas, the splitting resulted in the sum of a conservative portion and a non-conservative portion of the flux derivative. hereafter referred to as the "Entropy Splitting." There are several potential desirable attributes and side benefits of the entropy splitting for the compressible Euler equations that were not fully explored in Gerritsen and Olsson. The paper has several objectives. The first is to investigate the choice of the arbitrary parameter that determines the amount of splitting and its dependence on the type of physics of current interest to computational fluid dynamics. The second is to investigate in what manner the splitting affects the nonlinear stability of the central schemes for long time integrations of unsteady flows such as in nonlinear aeroacoustics and turbulence dynamics. If numerical dissipation indeed is needed to stabilize the central scheme, can the splitting help minimize the numerical dissipation compared to its un-split cousin? Extensive numerical study on the vortex preservation capability of the splitting in conjunction with central schemes for long time integrations will be presented. The third is to study the effect of the non-conservative proportion of splitting in obtaining the correct shock location for high speed complex shock

  6. Toward Scientific Numerical Modeling

    NASA Technical Reports Server (NTRS)

    Kleb, Bil

    2007-01-01

    Ultimately, scientific numerical models need quantified output uncertainties so that modeling can evolve to better match reality. Documenting model input uncertainties and verifying that numerical models are translated into code correctly, however, are necessary first steps toward that goal. Without known input parameter uncertainties, model sensitivities are all one can determine, and without code verification, output uncertainties are simply not reliable. To address these two shortcomings, two proposals are offered: (1) an unobtrusive mechanism to document input parameter uncertainties in situ and (2) an adaptation of the Scientific Method to numerical model development and deployment. Because these two steps require changes in the computational simulation community to bear fruit, they are presented in terms of the Beckhard-Harris-Gleicher change model.

  7. Two often disregarded aspects of Foucaultʼs pendulum

    NASA Astrophysics Data System (ADS)

    Pérez, José-Philippe; Pujol, Olivier

    2015-01-01

    This paper revisits the famous Foucault's pendulum by highlighting two often-disregarded aspects in mechanics courses. The first one concerns the existence of a local accelerated reference frame to express the law of dynamics without the Coriolis force. The second aspect deals with the geometrical phase that appears in pendulum dynamics. This last point, which could appear banal, should be related to analogous consideration in quantum physics. It is also linked to vectorial parallel transport of the pendulum angular momentum eigenvector. Numerical simulations with MATLAB are proposed.

  8. Insights into numerical cognition: considering eye-fixations in number processing and arithmetic.

    PubMed

    Mock, J; Huber, S; Klein, E; Moeller, K

    2016-05-01

    Considering eye-fixation behavior is standard in reading research to investigate underlying cognitive processes. However, in numerical cognition research eye-tracking is used less often and less systematically. Nevertheless, we identified over 40 studies on this topic from the last 40 years with an increase of eye-tracking studies on numerical cognition during the last decade. Here, we review and discuss these empirical studies to evaluate the added value of eye-tracking for the investigation of number processing. Our literature review revealed that the way eye-fixation behavior is considered in numerical cognition research ranges from investigating basic perceptual aspects of processing non-symbolic and symbolic numbers, over assessing the common representational space of numbers and space, to evaluating the influence of characteristics of the base-10 place-value structure of Arabic numbers and executive control on number processing. Apart from basic results such as reading times of numbers increasing with their magnitude, studies revealed that number processing can influence domain-general processes such as attention shifting-but also the other way round. Domain-general processes such as cognitive control were found to affect number processing. In summary, eye-fixation behavior allows for new insights into both domain-specific and domain-general processes involved in number processing. Based thereon, a processing model of the temporal dynamics of numerical cognition is postulated, which distinguishes an early stage of stimulus-driven bottom-up processing from later more top-down controlled stages. Furthermore, perspectives for eye-tracking research in numerical cognition are discussed to emphasize the potential of this methodology for advancing our understanding of numerical cognition.

  9. Introduction to Numerical Methods

    SciTech Connect

    Schoonover, Joseph A.

    2016-06-14

    These are slides for a lecture for the Parallel Computing Summer Research Internship at the National Security Education Center. This gives an introduction to numerical methods. Repetitive algorithms are used to obtain approximate solutions to mathematical problems, using sorting, searching, root finding, optimization, interpolation, extrapolation, least squares regresion, Eigenvalue problems, ordinary differential equations, and partial differential equations. Many equations are shown. Discretizations allow us to approximate solutions to mathematical models of physical systems using a repetitive algorithm and introduce errors that can lead to numerical instabilities if we are not careful.

  10. Collapse of a Liquid Column: Numerical Simulation and Experimental Validation

    NASA Astrophysics Data System (ADS)

    Cruchaga, Marcela A.; Celentano, Diego J.; Tezduyar, Tayfun E.

    2007-03-01

    This paper is focused on the numerical and experimental analyses of the collapse of a liquid column. The measurements of the interface position in a set of experiments carried out with shampoo and water for two different initial column aspect ratios are presented together with the corresponding numerical predictions. The experimental procedure was found to provide acceptable recurrence in the observation of the interface evolution. Basic models describing some of the relevant physical aspects, e.g. wall friction and turbulence, are included in the simulations. Numerical experiments are conducted to evaluate the influence of the parameters involved in the modeling by comparing the results with the data from the measurements. The numerical predictions reasonably describe the physical trends.

  11. [Medical-social aspects of multiple sclerosis].

    PubMed

    Vermersch, P; Marissal, J P

    2001-09-01

    On a daily basis the quality of life of patients suffering from multiple sclerosis (MS) partially depends on social measures. These are not specific to MS. Patients often need to be helped by hospital or town social services for the numerous and complicated administrative steps to be taken. The information given to a patient is of prime importance concerning his rights, particularly his occupational rights. Many organisations have to be contacted to obtain financial and material aids, even if the latter are considered insufficient in many fields especially for improvements in accommodation. An invalidity card may entitle its holder to certain tax reductions. The competences of the COTOREP are wide-ranging and include the recognition of the handicapped worker, his training and his regarding at work, his orientation and admission into a specialised structure, the degree of his invalidity rate and should his handicap justify it, benefits such as the handicapped adults allowance and the compensatory third person's allowance. It is essential to adopt a multidisciplinary way when dealing with MS in order to provide a better care, experiments in specialised structures and networks are being undertaken. Numerous partners are taking part in these new approaches and patient associations may find their place there. Social aspects have to be taken into account as well in the way the cost of the disease is evaluated in terms of money and humanity.

  12. Numerical-Optimization Program

    NASA Technical Reports Server (NTRS)

    Vanderplaats, Garret N.

    1991-01-01

    Automated Design Synthesis (ADS) computer program is general-purpose numerical-optimization program for design engineering. Provides wide range of options for solution of constrained and unconstrained function minimization problems. Suitable for such applications as minimum-weight design. Written in FORTRAN 77.

  13. Numerical Estimation in Preschoolers

    ERIC Educational Resources Information Center

    Berteletti, Ilaria; Lucangeli, Daniela; Piazza, Manuela; Dehaene, Stanislas; Zorzi, Marco

    2010-01-01

    Children's sense of numbers before formal education is thought to rely on an approximate number system based on logarithmically compressed analog magnitudes that increases in resolution throughout childhood. School-age children performing a numerical estimation task have been shown to increasingly rely on a formally appropriate, linear…

  14. Numerical methods in control

    NASA Astrophysics Data System (ADS)

    Mehrmann, Volker; Xu, Hongguo

    2000-11-01

    We study classical control problems like pole assignment, stabilization, linear quadratic control and H[infinity] control from a numerical analysis point of view. We present several examples that show the difficulties with classical approaches and suggest reformulations of the problems in a more general framework. We also discuss some new algorithmic approaches.

  15. Fluid mechanics aspects of magnetic drug targeting.

    PubMed

    Odenbach, Stefan

    2015-10-01

    Experiments and numerical simulations using a flow phantom for magnetic drug targeting have been undertaken. The flow phantom is a half y-branched tube configuration where the main tube represents an artery from which a tumour-supplying artery, which is simulated by the side branch of the flow phantom, branches off. In the experiments a quantification of the amount of magnetic particles targeted towards the branch by a magnetic field applied via a permanent magnet is achieved by impedance measurement using sensor coils. Measuring the targeting efficiency, i.e. the relative amount of particles targeted to the side branch, for different field configurations one obtains targeting maps which combine the targeting efficiency with the magnetic force densities in characteristic points in the flow phantom. It could be shown that targeting efficiency depends strongly on the magnetic field configuration. A corresponding numerical model has been set up, which allows the simulation of targeting efficiency for variable field configuration. With this simulation good agreement of targeting efficiency with experimental data has been found. Thus, the basis has been laid for future calculations of optimal field configurations in clinical applications of magnetic drug targeting. Moreover, the numerical model allows the variation of additional parameters of the drug targeting process and thus an estimation of the influence, e.g. of the fluid properties on the targeting efficiency. Corresponding calculations have shown that the non-Newtonian behaviour of the fluid will significantly influence the targeting process, an aspect which has to be taken into account, especially recalling the fact that the viscosity of magnetic suspensions depends strongly on the magnetic field strength and the mechanical load.

  16. Numerical modeling of enclosure convection

    NASA Technical Reports Server (NTRS)

    Duh, J. C.

    1989-01-01

    A numerical study on the steady and unsteady natural convection in two-dimensional rectangular enclosures has been performed by a time-accurate ADI finite difference scheme. The study covered a range of Rayleigh numbers between 1000 and 10 to the 7th, aspect ratios between 0.2 and 10.0, and tilt angles between -90 (heating from bottom) and +90 deg (heating from top). Various Prandtl numbers have been studied, but only the results of water (Pr = 7.0) are reported here due to space limitations. The physics revealed, however, includes the convection phenomena and the Rayleigh-Benard stability, as well as the combined mechanism of these two. The onset of secondary cells is determined by using a velocity map, which is simpler and cleaner, instead of a streamline plot. The critical Ra number for the occurrence of these secondary cells is shown to be lower than can be detected by experimental studies. On the Rayleigh-Benard stability part, a second transition from stable single-cell convection to periodic multicellular convection is disclosed.

  17. Supersymmetric chiral models: Geometrical aspects

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.

    1989-03-01

    We consider classical supersymmetric chiral models of field theory and focus our attention on the geometrical aspects of such theories. A characteristic feature of such models is that the interaction is not introduced by adding the interaction Lagrangian to the free field Lagrangian, but has a purely geometrical origin and is related to the inner curvature of the target manifold. In many aspects these models are analogous to gauge theories and, as became clear recently, they are also important for superstring theory, which nowadays is the most probable candidate for a truly unified theory of all interactions including gravitation.

  18. PSYCHOLOGICAL ASPECTS OF ATOMIC DISASTER

    PubMed Central

    Adams, Edward C.

    1954-01-01

    Increasing attention to the psychological aspects of atomic disaster will help improve the ability of the citizens of this country to withstand attack and survive as a free people. Since an enemy may be expected to exploit any internal weaknesses it can find, preparation must be made against the onslaught. The ability to deal effectively with any situation, even the most awesome, depends on knowledge of what to expect, and there is no reason to believe that facts about atomic disaster are an exception to this time proven truth. The psychological aspects need to be considered from two points of view, namely, the effect on masses of people and on individuals. PMID:13182616

  19. Perception of numerical methods in rarefied gasdynamics

    NASA Technical Reports Server (NTRS)

    Bird, G. A.

    1989-01-01

    The relationships between various numerical methods applied to problems in rarefied gasdynamics are discussed, with emphasis on conflicting viewpoints and computational requirements associated with physical simulation versus the numerical solution of the Boltzmann equation. The basic differences between the molecular dynamics and direct simulation methods are shown to affect their applicability to dense and rarefied flows. Methods for the probabilistic selection of representative collision in the direct simulation Monte Carlo method are reviewed. A method combining the most desirable features of the earlier methods is presented.

  20. Affect Consciousness in children with internalizing problems: Assessment of affect integration.

    PubMed

    Taarvig, Eva; Solbakken, Ole André; Grova, Bjørg; Monsen, Jon T

    2015-10-01

    Affect integration was operationalized through the Affect Consciousness (AC) construct as degrees of awareness, tolerance, nonverbal expression and conceptual expression of 11 affects. These aspects are assessed through a semi-structured Affect Consciousness Interview (ACI) and separate rating scales (Affect Consciousness Scales (ACSs)) developed for use in research and clinical work with adults with psychopathological disorders. Age-adjusted changes were made in the interview and rating system. This study explored the applicability of the adjusted ACI to a sample of 11-year-old children with internalizing problems through examining inter-rater reliability of the adjusted ACI, along with relationships between the AC aspects and aspects of mental health as symptoms of depression, symptoms of anxiety, social competence, besides general intelligence. Satisfactory inter-rater reliability was found, as well as consistent relationships between the AC aspects and the various aspects of mental health, a finding which coincides with previous research. The finding indicates that the attainment of the capacity to deal adaptively with affect is probably an important contributor to the development of adequate social competence and maybe in the prevention of psychopathology in children. The results indicate that the adjusted ACI and rating scales are useful tools in treatment planning with children at least from the age of 11 years.

  1. Numerical Prediction of Dust. Chapter 10

    NASA Technical Reports Server (NTRS)

    Benedetti, Angela; Baldasano, J. M.; Basart, S.; Benincasa, F.; Boucher, O.; Brooks, M.; Chen, J. P.; Colarco, P. R.; Gong, S.; Huneeus, N.; Jones, L; Lu, S.; Menut, L.; Mulcahy, J.; Nickovic, S.; Morcrette, J.-J.; Perez, C.; Reid, J. S.; Sekiyama, T. T.; Tanaka, T.; Terradellas, E.; Westphal, D. L.; Zhang, X.-Y.; Zhou, C.-H.

    2013-01-01

    Covers the whole breadth of mineral dust research, from a scientific perspective Presents interdisciplinary work including results from field campaigns, satellite observations, laboratory studies, computer modelling and theoretical studies Explores the role of dust as a player and recorder of environmental change This volume presents state-of-the-art research about mineral dust, including results from field campaigns, satellite observations, laboratory studies, computer modelling and theoretical studies. Dust research is a new, dynamic and fast-growing area of science and due to its multiple roles in the Earth system, dust has become a fascinating topic for many scientific disciplines. Aspects of dust research covered in this book reach from timescales of minutes (as with dust devils, cloud processes, and radiation) to millennia (as with loess formation and oceanic sediments), making dust both a player and recorder of environmental change. The book is structured in four main parts that explore characteristics of dust, the global dust cycle, impacts of dust on the Earth system, and dust as a climate indicator. The chapters in these parts provide a comprehensive, detailed overview of this highly interdisciplinary subject. The contributions presented here cover dust from source to sink and describe all the processes dust particles undergo while travelling through the atmosphere. Chapters explore how dust is lifted and transported, how it affects radiation, clouds, regional circulations, precipitation and chemical processes in the atmosphere, and how it deteriorates air quality. The book explores how dust is removed from the atmosphere by gravitational settling, turbulence or precipitation, how iron contained in dust fertilizes terrestrial and marine ecosystems, and about the role that dust plays in human health. We learn how dust is observed, simulated using computer models and forecast. The book also details the role of dust deposits for climate reconstructions

  2. Games, Gaming, and Gamification: Some Aspects of Motivation

    ERIC Educational Resources Information Center

    Hanson-Smith, Elizabeth

    2016-01-01

    Unsupported claims have been made for the use of games in education and the gamification (game-like aspects, such as scores and point goals) of various learning elements. This brief article examines what may be the motivational basis of gaming and how it can affect students' behavior and ultimate success.

  3. Multilingual Aspects of Fluency Disorders. Communication Disorders across Languages

    ERIC Educational Resources Information Center

    Howell, Peter; Van Borsel, John

    2011-01-01

    This book contains contributions by scholars working on diverse aspects of speech who bring their findings to bear on the practical issue of how to treat stuttering in different language groups and in multilingual speakers. The book considers classic issues in speech production research, as well as whether regions of the brain that are affected in…

  4. Community structure affects behavior.

    PubMed

    Jaenson, C

    1991-06-01

    AID's prevention efforts can benefit from taking into account 5 main aspects (KEPRA) of community structure identified by anthropologists: 1) kinship patterns, 2) economics, 3) politics, 4) religion, and 5) associations. For example, in Uganda among the Basoga and paternal aunt or senga is responsible for female sex education. Such culturally determined patterns need to be targeted in order to enhance education and effectiveness. Economics can reflect differing systems of family support through sexual means. The example given involves a poor family with a teenager in Thailand who exchanges a water buffalo or basic necessity for this daughter's prostitution. Politics must be considered because every society identifies people who have the power to persuade, influence, exchange resources, coerce, or in some way get people to do what is wanted. Utilizing these resources whether its ministers of health, factory owners, or peers is exemplified in the Monterey, Mexico factor floor supervisor and canteen worker introducing to workers the hows and whys of a new AID's education program. His peer status will command more respect than the director with direct authority. Religious beliefs have explanations for causes of sickness or disease, or provide instruction in sex practices. The example given is of a health workers in Uganda discussing AIDS with rural women by saying that we all know that disease and deaths are caused by spells. "But not AIDS - slim. AIDS is different." Associations can help provide educational, economic, and emotional assistance to the AID's effort or families affected.

  5. Additional aspects of elastohydrodynamic lubrication

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1978-01-01

    An up-to-date review of the varying aspects of elastohydrodynamic lubrication is presented.. Some recent work on elastohydrodynamic lubrication of materials of low elastic modulus as well as on hydrodynamic lubrication is included. Both these topics are applicable for contacts with any ellipticity parameter (ranging from a circular contact to a line contact).

  6. TWO ASPECT MARKERS IN MANDARIN.

    ERIC Educational Resources Information Center

    WANG, WILLIAM S-Y.

    TWO ASPECT MARKERS IN MANDARIN CHINESE ARE STUDIED WITHIN THE GENERAL FRAMEWORK OF A TRANSFORMATIONAL GRAMMAR. THEY ARE COMMONLY REPRESENTED AS "-LE," INDICATING COMPLETION OF ACTION, AND "-GUO," INDICATING THAT AN ACTION HAS TAKEN PLACE AT LEAST ONCE. THE PROBLEM INVOLVES SEVERAL SEEMING IRREGULARITIES IN THE FORMATION OF…

  7. Psychosocial Aspects of Heart Transplantation.

    ERIC Educational Resources Information Center

    Suszycki, Lee H.

    1988-01-01

    Presents an overview of medical and psychosocial aspects of heart transplantation, with a focus on the program at Columbia-Presbyterian Medical Center. Describes social workers' interventions which help patients and families to achieve optimal psychosocial functioning before and after transplantation. (Author/ABL)

  8. Legal Aspects of the Web.

    ERIC Educational Resources Information Center

    Borrull, Alexandre Lopez; Oppenheim, Charles

    2004-01-01

    Presents a literature review that covers the following topics related to legal aspects of the Web: copyright; domain names and trademarks; linking, framing, caching, and spamdexing; patents; pornography and censorship on the Internet; defamation; liability; conflict of laws and jurisdiction; legal deposit; and spam, i.e., unsolicited mails.…

  9. Neurologic aspects of drug abuse.

    PubMed

    Goforth, Harold W; Murtaugh, Reed; Fernandez, Francisco

    2010-02-01

    Neurologic aspects of drug abuse vary. This article explains the general nature of drug abuse, identifies the physiologic effects of certain drugs, and briefly describes the neurobiology of addiction. This article also reviews available treatment options for those addicted to substances of abuse, and clarifies common misconceptions, including the differences between tolerance, abuse, and addiction.

  10. Behavioral Aspects of Marijuana Use.

    ERIC Educational Resources Information Center

    Paulson, Patricia

    This paper examines the behavioral aspects of marijuana use. The focus of the study was to investigate the attitudes and practices toward drugs by users and non-users and the relationship of these attitudes and practices to selected psychosocial factors. A survey instrument in the form of an anonymous questionnaire was developed and administered…

  11. Gender Aspects of Human Security

    ERIC Educational Resources Information Center

    Moussa, Ghada

    2008-01-01

    The chapter deals with the gender dimensions in human security through focusing on the relationship between gender and human security, first manifested in international declarations and conventions, and subsequently evolving in world women conferences. It aims at analysing the various gender aspects in its relation to different human security…

  12. [Scientometric aspects of medical eponyms].

    PubMed

    Schubert, András

    2014-09-07

    Eponyms, scientific concepts named after persons, have a long tradition in medical sciences. Their emergence and use are rather instructive from the aspects of scientometrics, as well. Using a medical sample it is shown that although references to publications giving origin to the eponyms inevitably get obliterated, their citation rate is still many times higher than that of other publications of the same age.

  13. Mathematical Aspects of Electoral Systems

    NASA Astrophysics Data System (ADS)

    Konstantinov, M. M.

    2007-10-01

    In this paper we consider some mathematical aspects of electoral systems. Sometimes the results from elections seem paradoxical although they are mathematically correct. These cases are known as electoral paradoxes. A number of paradoxes of proportional and majoritarian electoral systems are considered.

  14. Aspects of Spirituality in Adolescents

    ERIC Educational Resources Information Center

    Bussing, Arndt; Foller-Mancini, Axel; Gidley, Jennifer; Heusser, Peter

    2010-01-01

    This paper analyses which aspects of spirituality are valued by adolescents, and how they are interconnected with youths' life satisfaction and "self-centeredness". The participants were 254 adolescents (11th grade) of four different high schools from west Germany. After re-validation of the 6-factorial student's version of the ASP…

  15. Pragmatic Aspects of Scalar Modifiers

    ERIC Educational Resources Information Center

    Sawada, Osamu

    2010-01-01

    This dissertation investigates the pragmatic aspects of scalar modifiers from the standpoint of the interface between semantics and pragmatics, focusing on (i) the (non) parallelism between the truth-conditional scalar modifiers and the non-truth-conditional scalar modifiers, (ii) the compositionality and dimensionality of non-truth-conditional…

  16. Information Based Numerical Practice.

    DTIC Science & Technology

    1987-02-01

    N I IIi I2 LA 1.6 liii I~JIIN MARYLAND COLLEGE PARK CAMPUS INSTITUTE FOR PHYSICAL SCIENCE AND TECHNOLOGY Technical Note S1-1059 INFORMATION BASED...K-0169 9. PERFORMING ORGANIZATION NMEU AMC ADDRESS 16. PROGRAM CELEMNT. PROJECT. TASK AREA & WORK UNIT NUNSERS, Institute for Physical Science and...BASED NUMERICAL PRACTICE I. Babuska Institute for Physical Science and Technology University of Maryland, College Park, MD 20740 a Partially supported by

  17. Numerical Relativistic Quantum Optics

    DTIC Science & Technology

    2013-11-08

    Introduction 1 II. Relativistic Wave Equations 2 III. Stationary States 4 A. Analytical Solutions for Coulomb Potentials 4 B. Numerical Solutions...C. Relativistic Ionization Example 15 V. Computational Performance 18 VI. Conclusions 21 VII. Acknowledgements 22 References 23 1 I. INTRODUCTION ...peculiar result that B0 = 1 TG is a weak field. At present, such fields are observed only in connection with astrophysical phenomena [14]. The highest

  18. Hybrid undulator numerical optimization

    SciTech Connect

    Hairetdinov, A.H.; Zukov, A.A.

    1995-12-31

    3D properties of the hybrid undulator scheme arc studied numerically using PANDIRA code. It is shown that there exist two well defined sets of undulator parameters which provide either maximum on-axis field amplitude or minimal higher harmonics amplitude of the basic undulator field. Thus the alternative between higher field amplitude or pure sinusoidal field exists. The behavior of the undulator field amplitude and harmonics structure for a large set of (undulator gap)/(undulator wavelength) values is demonstrated.

  19. Numerical Modeling of Airblast.

    DTIC Science & Technology

    1987-06-01

    REPORT SAIC 87/1701 June 1987 Dr.. Submitted to: cp Dr. Jay Boris Laboratory for Computational Physics Accet F4,r Naval Research Laboratory I...boundary layer physical assumptions provides an unsteady prediction of the mass flux emerging from the ground. This model was first proposed by Mirels...the physics modeled will be explained. High explosive dust cloud simulation provides a research path when combined with numerical calculations can lead

  20. Institutional and socioeconomic aspects of water supply

    NASA Astrophysics Data System (ADS)

    Rauchenschwandtner, H.; Pachel, M.

    2012-04-01

    Institutional and socioeconomic aspects of water supply Within the project CC-WaterS the participating researchers of the Vienna University of Economics and B.A. have been responsible for the analysis of the socioeconomic aspects related to water supply and climate change, the assessment of future water demands in the City of Vienna, as well as an estimation of economic consequences of possible water shortages and possible scope for the introduction of new legal guidelines. The institutional and socioeconomic dimensions of drinking water and sanitation systems are being examined by utilisation of different prognostic scenarios in order to assess future costs of water provisioning and future demands of main water users, thus providing an information basis and recommendations for policy and decision makers in the water sector. These dimensions, for example, include EU legislation - especially the Water Framework Directive -, national legislations and strategies targeted at achieving sustainability in water usage, best practices and different forms of regulating water markets, and an analysis of the implications of demographic change. As a basis this task encompasses research of given institutional, social, and legal-political structures in the area of water supply. In this course we provide an analysis of the structural characteristics of water markets, the role of water prices, the increasing perception of water as an economic good as well as implications thereof, the public awareness in regard to climate change and water resources, as well as related legal aspects and involved actors from regional to international level; and show how water resources and the different systems of water provisioning are affected by (ideological) conflicts on various levels. Furthermore, and in order to provide a solid basis for management recommendations related to climate change and water supply, an analytical risk-assessment framework based on the concepts of new institutional

  1. Computational Aspects of Constrained Estimation.

    DTIC Science & Technology

    1982-03-01

    34Dynamic Programming and Ill- Conditioned Linear Systems," Journal of Mathematical Analysis and Applications , 10, 1965, pp. 206-215. 37. J.A. Newkirk...34 Journal of Mathematical Analysis and Applications , 31, 1970, pp. 682-716. 78. J.M. Varah, "Numerical Solution of Ill-Posed Problems Using Interactive

  2. A numerical methodology for the Painlevé equations

    NASA Astrophysics Data System (ADS)

    Fornberg, Bengt; Weideman, J. A. C.

    2011-07-01

    The six Painlevé transcendents PI - PVI have both applications and analytic properties that make them stand out from most other classes of special functions. Although they have been the subject of extensive theoretical investigations for about a century, they still have a reputation for being numerically challenging. In particular, their extensive pole fields in the complex plane have often been perceived as 'numerical mine fields'. In the present work, we note that the Painlevé property in fact provides the opportunity for very fast and accurate numerical solutions throughout such fields. When combining a Taylor/Padé-based ODE initial value solver for the pole fields with a boundary value solver for smooth regions, numerical solutions become available across the full complex plane. We focus here on the numerical methodology, and illustrate it for the PI equation. In later studies, we will concentrate on mathematical aspects of both the PI and the higher Painlevé transcendents.

  3. On numerical simulation of viscous flows

    NASA Astrophysics Data System (ADS)

    Ghia, K. N.; Ghia, U.

    Numerical simulation methods for viscous incompressible laminar flows are reviewed, with a focus on finite-difference schemes. The approaches to high/moderate-Reynolds-number flows (strong-viscous-interaction model or single sets of equations) and the factors affecting the versatility, reliability, and accuracy of the analysis algorithms are considered; approximate-factorization implicit solution techniques for low-Reynolds-number flows are discussed; and the procedures used in a number of specific problems are indicated.

  4. Environmental aspects of congenital scoliosis.

    PubMed

    Li, Zheng; Yu, Xin; Shen, Jianxiong

    2015-04-01

    Growing evidence has proved that many aspects of our lifestyle and the environment contribute to the development of congenital disease. Congenital spinal deformities are due to anomalous development of the vertebrae including failure of formation and segmentation during embryogenesis. The causes of congenital scoliosis have not been fully identified. A variety of factors are implicated in the development of vertebral abnormalities. Previous studies have demonstrated that both genetics and environmental factors are implicated in the development of vertebral abnormalities. However, no specific cause for congenital scoliosis has been identified. In our review, we focus on the environmental factors for the development of congenital scoliosis. Various maternal exposures during pregnancy including hypoxia, alcohol use, vitamin deficiency, valproic acid, boric acid, and hyperthermia have been observed to be associated with the occurrence of congenital scoliosis. This review describes the major environmental contributors of congenital scoliosis with an emphasis on treatment aspects associated with environmental disposition in congenital scoliosis.

  5. Liposarcome dorsal: aspect clinique rare

    PubMed Central

    Agbessi, Odry; Arrob, Adil; Fiqhi, Kamal; Khalfi, Lahcen; Nassih, Mohammed; El Khatib, Karim

    2015-01-01

    Décrit la première fois par Virchow en 1860, le liposarcome est une tumeur mésenchymateuse rare. Cette rareté est relative car les liposarcomes représentent quand même 14 à 18% de l'ensemble des tumeurs malignes des parties molles et ils constituent le plus fréquent des sarcomes des parties molles. Pour la majorité des auteurs, il ne se développerait jamais sur un lipome ou une lipomatose préexistant. Nous rapportons un cas de volumineux liposarcome de la face dorsale du tronc. L'histoire de la maladie, l'aspect clinique inhabituel « de tumeur dans tumeur », l'aspect de la pièce opératoire nous fait évoquer la possibilité de la transformation maligne d'un lipome bénin préexistant. PMID:26113914

  6. "Recognizing Numerical Constants"

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Craw, James M. (Technical Monitor)

    1995-01-01

    The advent of inexpensive, high performance computer and new efficient algorithms have made possible the automatic recognition of numerically computed constants. In other words, techniques now exist for determining, within certain limits, whether a computed real or complex number can be written as a simple expression involving the classical constants of mathematics. In this presentation, some of the recently discovered techniques for constant recognition, notably integer relation detection algorithms, will be presented. As an application of these methods, the author's recent work in recognizing "Euler sums" will be described in some detail.

  7. Thermodynamic aspects of therapeutic hypothermia.

    PubMed

    Vanlandingham, Sean C; Kurz, Michael C; Wang, Henry E

    2015-01-01

    Therapeutic hypothermia (TH) is an important treatment for post-cardiac arrest syndrome. Despite its widespread practice, only limited data describe the thermodynamic aspects of heat transfer during TH. This paper reviews the principles of human body heat balance and provides a conceptual model for characterizing heat exchange during TH. The model may provide a framework for computer simulation for improving training in or clinical methods of TH.

  8. Legal aspects of satellite teleconferencing

    NASA Technical Reports Server (NTRS)

    Smith, D. D.

    1971-01-01

    The application of satellite communications for teleconferencing purposes is discussed. The legal framework within which such a system or series of systems could be developed is considered. The analysis is based on: (1) satellite teleconferencing regulation, (2) the options available for such a system, (3) regulatory alternatives, and (4) ownership and management aspects. The system is designed to provide a capability for professional education, remote medical diagnosis, business conferences, and computer techniques.

  9. Confidence in Numerical Simulations

    SciTech Connect

    Hemez, Francois M.

    2015-02-23

    This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to “forecast,” that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists “think.” This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. “Confidence” derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

  10. Numerical Propulsion System Simulation

    NASA Technical Reports Server (NTRS)

    Naiman, Cynthia

    2006-01-01

    The NASA Glenn Research Center, in partnership with the aerospace industry, other government agencies, and academia, is leading the effort to develop an advanced multidisciplinary analysis environment for aerospace propulsion systems called the Numerical Propulsion System Simulation (NPSS). NPSS is a framework for performing analysis of complex systems. The initial development of NPSS focused on the analysis and design of airbreathing aircraft engines, but the resulting NPSS framework may be applied to any system, for example: aerospace, rockets, hypersonics, power and propulsion, fuel cells, ground based power, and even human system modeling. NPSS provides increased flexibility for the user, which reduces the total development time and cost. It is currently being extended to support the NASA Aeronautics Research Mission Directorate Fundamental Aeronautics Program and the Advanced Virtual Engine Test Cell (AVETeC). NPSS focuses on the integration of multiple disciplines such as aerodynamics, structure, and heat transfer with numerical zooming on component codes. Zooming is the coupling of analyses at various levels of detail. NPSS development includes capabilities to facilitate collaborative engineering. The NPSS will provide improved tools to develop custom components and to use capability for zooming to higher fidelity codes, coupling to multidiscipline codes, transmitting secure data, and distributing simulations across different platforms. These powerful capabilities extend NPSS from a zero-dimensional simulation tool to a multi-fidelity, multidiscipline system-level simulation tool for the full development life cycle.

  11. The Maya Project: Numerical Simulations of Black Hole Collisions

    NASA Astrophysics Data System (ADS)

    Smith, Kenneth; Calabrese, Gioel; Garrison, David; Kelly, Bernard; Laguna, Pablo; Lockitch, Keith; Pullin, Jorge; Shoemaker, Deirdre; Tiglio, Manuel

    2001-04-01

    The main objective of the MAYA project is the development of a numerical code to solve the vacuum Einstein's field equations for spacetimes containing multiple black hole singularities. Incorporating knowledge gained from previous similar efforts (Binary Black Holes Alliance and the AGAVE project) as well as one-dimensional numerical studies, MAYA has been built from the ground up within the architecture of Cactus 4.0, with particular attention paid to the software engineering aspects of code development. The goal of this new effort is to ultimately have a robust, efficient, readable, and stable numerical code for black hole evolution. This poster presents an overview of the project, focusing on the innovative aspects of the project as well as its current development status.

  12. Numerical and physical magnitudes are mapped into time.

    PubMed

    Ben-Meir, Shachar; Ganor-Stern, Dana; Tzelgov, Joseph

    2012-01-01

    In two experiments we investigated mapping of numerical and physical magnitudes with temporal order. Pairs of digits were presented sequentially for a size comparison task. An advantage for numbers presented in ascending order was found when participants were comparing the numbers' physical and numerical magnitudes. The effect was more robust for comparisons of physical size, as it was found using both select larger and select smaller instructions, while for numerical comparisons it was found only for select larger instructions. Varying both the digits' numerical and physical sizes resulted in a size congruity effect, indicating automatic processing of the irrelevant magnitude dimension. Temporal order and the congruency between numerical and physical magnitudes affected comparisons in an additive manner, thus suggesting that they affect different stages of the comparison process.

  13. Practical Aspects of Birdcage Coils

    NASA Astrophysics Data System (ADS)

    Doty, F. David; Entzminger, George; Hauck, Cory D.; Staab, John P.

    1999-05-01

    Numerical modeling and experimental results are presented for a variety of birdcages for high-field MRI microscopy. The data include the first published numerical calculations and experimental measurements of magnetic filling factors of birdcages or other MRI coils. Fast, 3D calculations for shielded coils are demonstrated using the Biot-Savart law along with energy minimization. It is shown that the near-field, higher-order inhomogeneity effects remaining after a first-order, asymmetry correction may easily exceed 20% in situations where it is desirable to maximize filling factor. It is also found that an order-of-magnitude improvement in the accuracy of predicted capacitor values may be achieved by using a more detailed circuit model of the birdcage resonator.

  14. Practical aspects of birdcage coils.

    PubMed

    Doty, F D; Entzminger, G; Hauck, C D; Staab, J P

    1999-05-01

    Numerical modeling and experimental results are presented for a variety of birdcages for high-field MRI microscopy. The data include the first published numerical calculations and experimental measurements of magnetic filling factors of birdcages or other MRI coils. Fast, 3D calculations for shielded coils are demonstrated using the Biot-Savart law along with energy minimization. It is shown that the near-field, higher-order inhomogeneity effects remaining after a first-order, asymmetry correction may easily exceed 20% in situations where it is desirable to maximize filling factor. It is also found that an order-of-magnitude improvement in the accuracy of predicted capacitor values may be achieved by using a more detailed circuit model of the birdcage resonator.

  15. Aspects of Diversity Measurement for Microbial Communities

    PubMed Central

    Mills, Aaron L.; Wassel, Raymond A.

    1980-01-01

    A useful measure of diversity was calculated for microbial communities collected from lake water and sediment samples using the Shannon index (H′) and rarefaction [E(S)]. Isolates were clustered by a numerical taxonomy approach in which limited (<20) tests were used so that the groups obtained represented a level of resolution other than species. The numerical value of diversity for each sample was affected by the number of tests used; however, the relative diversity compared among several sampling locations was the same whether 11 or 19 characters were examined. The number of isolates (i.e., sample size) strongly influenced the value of H′ so that unequal sized samples could not be compared. Rarefaction accounts for differences in sample size inherently so that such comparisons are made simple. Due to the type of sampling carried out by microbiologists, H′ is estimated and not determined and therefore requires a statement of error associated with it. Failure to report error provided potentially misleading results. Calculation of the variance of H′ is not a simple matter and may be impossible when handling a large number of samples. With rarefaction, the variance of E(S) is readily determined, facilitating the comparison of many samples. PMID:16345636

  16. Using PASCAL for numerical analysis

    NASA Technical Reports Server (NTRS)

    Volper, D.; Miller, T. C.

    1978-01-01

    The data structures and control structures of PASCAL enhance the coding ability of the programmer. Proposed extensions to the language further increase its usefulness in writing numeric programs and support packages for numeric programs.

  17. Perspectives in numerical astrophysics:

    NASA Astrophysics Data System (ADS)

    Reverdy, V.

    2016-12-01

    In this discussion paper, we investigate the current and future status of numerical astrophysics and highlight key questions concerning the transition to the exascale era. We first discuss the fact that one of the main motivation behind high performance simulations should not be the reproduction of observational or experimental data, but the understanding of the emergence of complexity from fundamental laws. This motivation is put into perspective regarding the quest for more computational power and we argue that extra computational resources can be used to gain in abstraction. Then, the readiness level of present-day simulation codes in regard to upcoming exascale architecture is examined and two major challenges are raised concerning both the central role of data movement for performances and the growing complexity of codes. Software architecture is finally presented as a key component to make the most of upcoming architectures while solving original physics problems.

  18. Numerical relativity beyond astrophysics.

    PubMed

    Garfinkle, David

    2017-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  19. Numerical relativity beyond astrophysics

    NASA Astrophysics Data System (ADS)

    Garfinkle, David

    2017-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  20. Test aspects of the JPL Viterbi decoder

    NASA Technical Reports Server (NTRS)

    Breuer, M. A.

    1989-01-01

    The generation of test vectors and design-for-test aspects of the Jet Propulsion Laboratory (JPL) Very Large Scale Integration (VLSI) Viterbi decoder chip is discussed. Each processor integrated circuit (IC) contains over 20,000 gates. To achieve a high degree of testability, a scan architecture is employed. The logic has been partitioned so that very few test vectors are required to test the entire chip. In addition, since several blocks of logic are replicated numerous times on this chip, test vectors need only be generated for each block, rather than for the entire circuit. These unique blocks of logic have been identified and test sets generated for them. The approach employed for testing was to use pseudo-exhaustive test vectors whenever feasible. That is, each cone of logid is tested exhaustively. Using this approach, no detailed logic design or fault model is required. All faults which modify the function of a block of combinational logic are detected, such as all irredundant single and multiple stuck-at faults.

  1. Regularity Aspects in Inverse Musculoskeletal Biomechanics

    NASA Astrophysics Data System (ADS)

    Lund, Marie; Stâhl, Fredrik; Gulliksson, Mârten

    2008-09-01

    Inverse simulations of musculoskeletal models computes the internal forces such as muscle and joint reaction forces, which are hard to measure, using the more easily measured motion and external forces as input data. Because of the difficulties of measuring muscle forces and joint reactions, simulations are hard to validate. One way of reducing errors for the simulations is to ensure that the mathematical problem is well-posed. This paper presents a study of regularity aspects for an inverse simulation method, often called forward dynamics or dynamical optimization, that takes into account both measurement errors and muscle dynamics. Regularity is examined for a test problem around the optimum using the approximated quadratic problem. The results shows improved rank by including a regularization term in the objective that handles the mechanical over-determinancy. Using the 3-element Hill muscle model the chosen regularization term is the norm of the activation. To make the problem full-rank only the excitation bounds should be included in the constraints. However, this results in small negative values of the activation which indicates that muscles are pushing and not pulling, which is unrealistic but the error maybe small enough to be accepted for specific applications. These results are a start to ensure better results of inverse musculoskeletal simulations from a numerical point of view.

  2. Mechanical engineering aspects of TFTR

    SciTech Connect

    Citrolo, J.C.

    1983-04-01

    This paper briefly presents the principles which characterize a tokamak and discusses the mechanical aspects of TFTR, particularly the toroidal field coils and the vacuum chamber, in the context of being key components common to all tokamaks. The mechanical loads on these items as well as other design requirements are considered and the solutions to these requirements as executed in TFTR are presented. Future technological developments beyond the scope of TFTR, which are necessary to bring the tokamak concept to a full fusion-power system, are also presented. Additional methods of plasma heating, current drive, and first wall designs are examples of items in this category.

  3. Practical Aspects of Nonlinear Optimization.

    DTIC Science & Technology

    1981-06-19

    14. E. Levitan and B . Polyak, "Constrained Minimization Methods", USSR Comp. Math. and Math. Physics 6, 1, (1966). 15. J. May, "Solving Nonlinear...AD-AIO 858 MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB F/G 12/1 PRACTICAL ASPECTS OF NONLINEAR OPTIMIZATION.U) JUN 81 R B HOLMES, J W TOLLESON...dj, l<j< m , (2) with the understanding the Q so defined has a non-empty interior (is "solid"). No qualitative assumptions on the objective - i

  4. Nutritional aspects related to endometriosis.

    PubMed

    Halpern, Gabriela; Schor, Eduardo; Kopelman, Alexander

    2015-01-01

    This literature review analyzed the evidence on nutritional aspects related to the pathogenesis and progression of endometriosis. Diets deficient in nutrients result in changes in lipid metabolism, oxidative stress and promote epigenetic abnormalities, that may be involved in the genesis and progression of the disease. Foods rich in omega 3 with anti-inflammatory effects, supplementation with N-acetylcysteine, vitamin D and resveratrol, in addition to the increased consumption of fruits, vegetables (preferably organic) and whole grains exert a protective effect, reducing the risk of development and possible regression of disease. Dietary re-education seems to be a promising tool in the prevention and treatment of endometriosis.

  5. Technical aspects of abdominal stomas.

    PubMed

    Link, Brian A; Kropp, Bradley; Frimberger, Dominic

    2007-01-01

    Continent urinary diversion has gained increasing popularity in the pediatric population during the last few decades. In adults, continent diversions are usually needed to replace a bladder after cystectomy for invasive carcinoma. Subsequently, the creation of functional and cosmetically hidden urinary and cecal abdominal stomas has become an integral part of many urinary reconstructive procedures. These techniques, originally developed for pediatric urinary reconstruction have gained increasing popularity for adult patients in need of a continence procedure. In the current manuscript, we review the technical aspects of site selection, mucocutaneous anastomosis, cosmetic appearance, and management of associated complications.

  6. Immunological aspects of cancer chemotherapy.

    PubMed

    Zitvogel, Laurence; Apetoh, Lionel; Ghiringhelli, François; Kroemer, Guido

    2008-01-01

    Accumulating evidence indicates that the innate and adaptive immune systems make a crucial contribution to the antitumour effects of conventional chemotherapy-based and radiotherapy-based cancer treatments. Moreover, the molecular and cellular bases of the immunogenicity of cell death that is induced by cytotoxic agents are being progressively unravelled, challenging the guidelines that currently govern the development of anticancer drugs. Here, we review the immunological aspects of conventional cancer treatments and propose that future successes in the fight against cancer will rely on the development and clinical application of combined chemo- and immunotherapies.

  7. Numeric Databases in the Sciences.

    ERIC Educational Resources Information Center

    Meschel, S. V.

    1984-01-01

    Provides exploration into types of numeric databases available (also known as source databases, nonbibliographic databases, data-files, data-banks, fact banks); examines differences and similarities between bibliographic and numeric databases; identifies disciplines that utilize numeric databases; and surveys representative examples in the…

  8. Investigating legal aspects of cyberbullying.

    PubMed

    Paul, Simone; Smith, Peter K; Blumberg, Herbert H

    2012-11-01

    In the UK schools are required by law to protect students from bullying; the responsibility of teachers to govern such behaviour has been extended outside the school setting to include cyberbullying. In this investigation, cyberbullying in secondary education is explored from the student perspective using a qualitative method of enquiry. Reported awareness and understanding about the legal aspects of cyberbullying are investigated; consideration is given to legislation, cybercrime, children's rights, school sanctions and safeguarding responsibilities. A total of 197 male and female students aged between 11 and 14 years old participated. Despite the availability of information on guidelines and legislation at national, local, and school level, this does not appear to have reached ground level of the individual student. There is a considerable gap between what students should know and what they report to be aware of with regard to legal aspects of cyberbullying. To address concerns of keeping up with the pace of change in cyberbullying, a collaborative approach is required with young people and adults sharing expertise.

  9. Mechanical aspects of CO₂ angiography.

    PubMed

    Corazza, Ivan; Rossi, Pier Luca; Feliciani, Giacomo; Pisani, Luca; Zannoli, Sebastiano; Zannoli, Romano

    2013-01-01

    The aim of this paper is to clarify some physical-mechanical aspects involved in the carbon dioxide angiography procedure (CO₂ angiography), with a particular attention to a possible damage of the vascular wall. CO₂ angiography is widely used on patients with iodine intolerance. The injection of a gaseous element, in most cases manually performed, requires a long training period. Automatic systems allow better control of the injection and the study of the mechanical behaviour of the gas. CO₂ injections have been studied by using manual and automatic systems. Pressures, flows and jet shapes have been monitored by using a cardiovascular mock. Photographic images of liquid and gaseous jet have been recorded in different conditions, and the vascular pressure rises during injection have been monitored. The shape of the liquid jet during the catheter washing phase is straight in the catheter direction and there is no jet during gas injection. Gas bubbles are suddenly formed at the catheter's hole and move upwards: buoyancy is the only governing phenomenon and no bubbles fragmentation is detected. The pressure rise in the vessel depends on the injection pressure and volume and in some cases of manual injection it may double the basal vascular pressure values. CO₂ angiography is a powerful and safe procedure which diffusion will certainly increase, although some aspects related to gas injection and chamber filling are not jet well known. The use of an automatic system permits better results, shorter training period and limitation of vascular wall damage risk.

  10. Terminological aspects of data elements

    SciTech Connect

    Strehlow, R.A. ); Kenworthey, W.H. Jr. ); Schuldt, R.E. )

    1991-01-01

    The creation and display of data comprise a process that involves a sequence of steps requiring both semantic and systems analysis. An essential early step in this process is the choice, definition, and naming of data element concepts and is followed by the specification of other needed data element concept attributes. The attributes and the values of data element concept remain associated with them from their birth as a concept to a generic data element that serves as a template for final application. Terminology is, therefore, centrally important to the entire data creation process. Smooth mapping from natural language to a database is a critical aspect of database, and consequently, it requires terminology standardization from the outset of database work. In this paper the semantic aspects of data elements are analyzed and discussed. Seven kinds of data element concept information are considered and those that require terminological development and standardization are identified. The four terminological components of a data element are the hierarchical type of a concept, functional dependencies, schematas showing conceptual structures, and definition statements. These constitute the conventional role of terminology in database design. 12 refs., 8 figs., 1 tab.

  11. Exploring the Educational Benefits of Introducing Aspect-Oriented Programming Into a Programming Course

    ERIC Educational Resources Information Center

    Boticki, I.; Katic, M.; Martin,S.

    2013-01-01

    This paper explores the educational benefits of introducing the aspect-oriented programming paradigm into a programming course in a study on a sample of 75 undergraduate software engineering students. It discusses how using the aspect-oriented paradigm, in addition to the object-oriented programming paradigm, affects students' programs, their exam…

  12. A numerical simulation of finite-length Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Streett, C. L.; Hussaini, M. Y.

    1988-01-01

    Results from numerical simulations of finite-length Taylor-Couette flow are presented. Included are time-accurate and steady-state studies of the change in the nature of the symmetric two-cell/asymmetric one-cell bifurcation with varying aspect ratio and of the Reynolds number/aspect ratio locus of the two-cell/four-cell bifurcation. Preliminary results from wavy-vortex simulations at low aspect ratios are also presented.

  13. Affective processing requires awareness.

    PubMed

    Lähteenmäki, Mikko; Hyönä, Jukka; Koivisto, Mika; Nummenmaa, Lauri

    2015-04-01

    Studies using backward masked emotional stimuli suggest that affective processing may occur outside visual awareness and imply primacy of affective over semantic processing, yet these experiments have not strictly controlled for the participants' awareness of the stimuli. Here we directly compared the primacy of affective versus semantic categorization of biologically relevant stimuli in 5 experiments (n = 178) using explicit (semantic and affective discrimination; Experiments 1-3) and implicit (semantic and affective priming; Experiments 4-5) measures. The same stimuli were used in semantic and affective tasks. Visual awareness was manipulated by varying exposure duration of the masked stimuli, and subjective level of stimulus awareness was measured after each trial using a 4-point perceptual awareness scale. When participants reported no awareness of the stimuli, semantic and affective categorization were at chance level and priming scores did not differ from zero. When participants were even partially aware of the stimuli, (a) both semantic and affective categorization could be performed above chance level with equal accuracy, (b) semantic categorization was faster than affective categorization, and (c) both semantic and affective priming were observed. Affective categorization speed was linearly dependent on semantic categorization speed, suggesting dependence of affective processing on semantic recognition. Manipulations of affective and semantic categorization tasks revealed a hierarchy of categorization operations beginning with basic-level semantic categorization and ending with superordinate level affective categorization. We conclude that both implicit and explicit affective and semantic categorization is dependent on visual awareness, and that affective recognition follows semantic categorization.

  14. Evolution: geometrical and dynamical aspects.

    PubMed

    Freguglia, Paolo; Bazzani, Armando

    2003-01-01

    We develop a possible axiomatic approach to the evolution theory that has been previously discussed in Freguglia [2002]. The axioms synthesize the fundamental ideas of evolution theory and allow a geometrical and dynamical interpretation of the generation law. Using the axioms we derive a simple reaction-diffusion model which introduces the species as self-organized stationary distribution of a finite population and simulates the evolution of a phenotypic character under the effect of an external perturbing action. The dynamical properties of the model are briefly presented using numerical simulations.

  15. Symposium on Numerical and Physical Aspects of Aerodynamic Flows (2nd), 17-20 January 1983,

    DTIC Science & Technology

    1983-01-01

    of diamond Ref. 19. cross section at M = 3.88, a = 100. L =10 V. Discussion of Results and Conclusions An examination of the test cases described in MI ...CR 2675, Apr. 1976. 18. Jorgensen, L . H., "Inclined Bodies of Various Cross Sections at Supersonic Speeds" NASA * 7. Solomon, J. M., Ciment , M...1983 UNCLSIFIEDG 28/4 N . .. . •-.- - - - ;. r -r’ r.-- • U., .". . -: - " • -2 ... .. -. . U~U L .. Li I, _ , . o1 WIII._.25--.0-1.6

  16. Computational and numerical aspects of using the integral equation method for adhesive layer fracture mechanics analysis

    SciTech Connect

    Giurgiutiu, V.; Ionita, A.; Dillard, D.A.; Graffeo, J.K.

    1996-12-31

    Fracture mechanics analysis of adhesively bonded joints has attracted considerable attention in recent years. A possible approach to the analysis of adhesive layer cracks is to study a brittle adhesive between 2 elastic half-planes representing the substrates. A 2-material 3-region elasticity problem is set up and has to be solved. A modeling technique based on the work of Fleck, Hutchinson, and Suo is used. Two complex potential problems using Muskelishvili`s formulation are set up for the 3-region, 2-material model: (a) a distribution of edge dislocations is employed to simulate the crack and its near field; and (b) a crack-free problem is used to simulate the effect of the external loading applied in the far field. Superposition of the two problems is followed by matching tractions and displacements at the bimaterial boundaries. The Cauchy principal value integral is used to treat the singularities. Imposing the traction-free boundary conditions over the entire crack length yielded a linear system of two integral equations. The parameters of the problem are Dundurs` elastic mismatch coefficients, {alpha} and {beta}, and the ratio c/H representing the geometric position of the crack in the adhesive layer.

  17. Analytical and numerical aspects in solving the controlled 3D Gross-Pitaevskii equation

    NASA Astrophysics Data System (ADS)

    Fedele, R.; Jovanović, D.; De Nicola, S.; Eliasson, B.; Shukla, P. K.

    2009-11-01

    The results of recently developed investigations, that have been carried out within the framework of the controlling potential method (CPM), are reviewed. This method allows one to decompose a three dimensional (3D) Gross-Pitaevskii equation (GPE) into the pair of coupled Schrödinger-type equations. Under suitable mathematical conditions, the solutions of the 3D controlled GPE can be constructed from the solutions of a 2D linear Schrödinger equation (the transverse component of the GPE) coupled with a 1D nonlinear Schrödinger equation (the longitudinal component of the GPE). Such decomposition allows one to cast the solutions in the form of the product of the solutions of the transverse and the longitudinal components of the GPE. The coupling between these two equations is the functional of both the transverse and the longitudinal profiles. It is shown that the CPM can be used to obtain a new class of three-dimensional solitary waves solutions of the GPE, which governs the dynamics of Bose-Einstein condensates. By imposing an external controlling potential, the desired time-dependent shape of the localized BECs is obtained. The stability of the exact solutions was checked with direct simulations of the time -dependent, three-dimensional GPE. Our simulations show that the localized condensates are stable with respect to perturbed initial conditions.

  18. Analytical and numerical aspects in solving the controlled 3D Gross-Pitaevskii equation

    SciTech Connect

    Fedele, R.; Jovanovic, D.; De Nicola, S.; Eliasson, B.; Shukla, P. K.

    2009-11-10

    The results of recently developed investigations, that have been carried out within the framework of the controlling potential method (CPM), are reviewed. This method allows one to decompose a three dimensional (3D) Gross-Pitaevskii equation (GPE) into the pair of coupled Schroedinger-type equations. Under suitable mathematical conditions, the solutions of the 3D controlled GPE can be constructed from the solutions of a 2D linear Schroedinger equation (the transverse component of the GPE) coupled with a 1D nonlinear Schroedinger equation (the longitudinal component of the GPE). Such decomposition allows one to cast the solutions in the form of the product of the solutions of the transverse and the longitudinal components of the GPE. The coupling between these two equations is the functional of both the transverse and the longitudinal profiles. It is shown that the CPM can be used to obtain a new class of three-dimensional solitary waves solutions of the GPE, which governs the dynamics of Bose-Einstein condensates. By imposing an external controlling potential, the desired time-dependent shape of the localized BECs is obtained. The stability of the exact solutions was checked with direct simulations of the time -dependent, three-dimensional GPE. Our simulations show that the localized condensates are stable with respect to perturbed initial conditions.

  19. Numerical Aspects of Nonhydrostatic Implementations Applied to a Parallel Finite Element Tsunami Model

    NASA Astrophysics Data System (ADS)

    Fuchs, A.; Androsov, A.; Harig, S.; Hiller, W.; Rakowsky, N.

    2012-04-01

    Based on the jeopardy of devastating tsunamis and the unpredictability of such events, tsunami modelling as part of warning systems is still a contemporary topic. The tsunami group of Alfred Wegener Institute developed the simulation tool TsunAWI as contribution to the Early Warning System in Indonesia. Although the precomputed scenarios for this purpose qualify for satisfying deliverables, the study of further improvements continues. While TsunAWI is governed by the Shallow Water Equations, an extension of the model is based on a nonhydrostatic approach. At the arrival of a tsunami wave in coastal regions with rough bathymetry, the term containing the nonhydrostatic part of pressure, that is neglected in the original hydrostatic model, gains in importance. In consideration of this term, a better approximation of the wave is expected. Differences of hydrostatic and nonhydrostatic model results are contrasted in the standard benchmark problem of a solitary wave runup on a plane beach. The observation data provided by Titov and Synolakis (1995) serves as reference. The nonhydrostatic approach implies a set of equations that are similar to the Shallow Water Equations, so the variation of the code can be implemented on top. However, this additional routines cause a lot of issues you have to cope with. So far the computations of the model were purely explicit. In the nonhydrostatic version the determination of an additional unknown and the solution of a large sparse system of linear equations is necessary. The latter constitutes the lion's share of computing time and memory requirement. Since the corresponding matrix is only symmetric in structure and not in values, an iterative Krylov Subspace Method is used, in particular the restarted Generalized Minimal Residual Algorithm GMRES(m). With regard to optimization, we present a comparison of several combinations of sequential and parallel preconditioning techniques respective number of iterations and setup/application time. Since the used software package pARMS 3.2, that provides solving and preconditioning techniques, works via MPI parallelism, in an auxiliary branch we adapted TsunAWI and switched from OpenMP to MPI with attached importance to internal partition management.

  20. Personalized numerical observer

    NASA Astrophysics Data System (ADS)

    Brankov, Jovan G.; Pretorius, P. Hendrik

    2010-02-01

    It is widely accepted that medical image quality should be assessed using task-based criteria, such as humanobserver (HO) performance in a lesion-detection (scoring) task. HO studies are time consuming and cost prohibitive to be used for image quality assessment during development of either reconstruction methods or imaging systems. Therefore, a numerical observer (NO), a HO surrogate, is highly desirable. In the past, we have proposed and successfully tested a NO based on a supervised-learning approach (namely a support vector machine) for cardiac gated SPECT image quality assessment. In the supervised-learning approach, the goal is to identify the relationship between measured image features and HO myocardium defect likelihood scores. Thus far we have treated multiple HO readers by simply averaging or pooling their respective scores. Due to observer variability, this may be suboptimal and less accurate. Therefore, in this work, we are setting our goal to predict individual observer scores independently in the hope to better capture some relevant lesion-detection mechanism of the human observers. This is even more important as there are many ways to get equivalent observer performance (measured by area under receiver operating curve), and simply predicting some joint (average or pooled) score alone is not likely to succeed.

  1. Numerical Relativity and Astrophysics

    NASA Astrophysics Data System (ADS)

    Lehner, Luis; Pretorius, Frans

    2014-08-01

    Throughout the Universe many powerful events are driven by strong gravitational effects that require general relativity to fully describe them. These include compact binary mergers, black hole accretion, and stellar collapse, where velocities can approach the speed of light and extreme gravitational fields (ΦNewt/c2≃1) mediate the interactions. Many of these processes trigger emission across a broad range of the electromagnetic spectrum. Compact binaries further source strong gravitational wave emission that could directly be detected in the near future. This feat will open up a gravitational wave window into our Universe and revolutionize our understanding of it. Describing these phenomena requires general relativity, and—where dynamical effects strongly modify gravitational fields—the full Einstein equations coupled to matter sources. Numerical relativity is a field within general relativity concerned with studying such scenarios that cannot be accurately modeled via perturbative or analytical calculations. In this review, we examine results obtained within this discipline, with a focus on its impact in astrophysics.

  2. Epidemiological aspects of heart diseases

    PubMed Central

    Shi, Aimin; Tao, Ziqi; Wei, Peng; Zhao, Jing

    2016-01-01

    Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Coronary heart disease (CHD) is the main cause of mortality in heart patients following stroke, rheumatic heart disease and myocardial infarctions. Approximately 80% of individuals succumb to CVDs, due to poor living conditions in low and middle income families and malnutrition. Infectious diseases, human immunodeficiency, tuberculosis, malaria, high blood pressure or hypertension, obesity and overweight, and nutritional disorders including smoking, excessive alcohol consumption, high salt and sugar intake, as well as other factors are responsible for CVDs and CHDs in young as well as elderly individuals. The focus of the present review are recent epidemiological aspects of CVD and CHD as well as the usefulness of a Mediterranean diet for heart patients and the prevention of heart diseases. PMID:27602082

  3. Technical aspects of fuel reprocessing

    SciTech Connect

    Groenier, W.S.

    1982-02-01

    The purpose of this paper is to present a brief description of fuel reprocessing and some present developments which show the reliability of nuclear energy as a long-term supply. The following topics are discussed: technical reasons for reprocessing; economic reasons for reprocessing; past experience; justification for advanced reprocessing R and D; technical aspects of current reprocessing development. The present developments are mainly directed at the reprocessing of breeder reactor fuels but there are also many applications to light-water reactor fuel reprocessing. These new developments involve totally remote operation, and maintenance. To demonstrate this advanced reprocessing concept, pilot-scale demonstration facilities are planned with commercial application occurring sometime after the year 2000. (ATT)

  4. Evolutionary Aspects of Enzyme Dynamics*

    PubMed Central

    Klinman, Judith P.; Kohen, Amnon

    2014-01-01

    The role of evolutionary pressure on the chemical step catalyzed by enzymes is somewhat enigmatic, in part because chemistry is not rate-limiting for many optimized systems. Herein, we present studies that examine various aspects of the evolutionary relationship between protein dynamics and the chemical step in two paradigmatic enzyme families, dihydrofolate reductases and alcohol dehydrogenases. Molecular details of both convergent and divergent evolution are beginning to emerge. The findings suggest that protein dynamics across an entire enzyme can play a role in adaptation to differing physiological conditions. The growing tool kit of kinetics, kinetic isotope effects, molecular biology, biophysics, and bioinformatics provides means to link evolutionary changes in structure-dynamics function to the vibrational and conformational states of each protein. PMID:25210031

  5. [Clinical aspects of witchcraft delusions].

    PubMed

    Pashkovskiĭ, V E

    2005-01-01

    To distinguish clinical variants and to specify nosologic entity of witchcraft delusions, 69 patients (10 males, aged 15-72 years) have been examined. It was found that witchcraft delusions exist in passive and active forms. In a passive form, the patient is sure that unknown (mystic) power damaged him/her; in an active form the patient, possessing a gift for unusual abilities, can influence the others (bewitches, heals, etc). Five clinical syndromes, in the structure of which the above delusions were found, namely, paranoiac-hypochondriac, hallucination-paranoid, depressive-paranoid, paraphrenic and delirious, were identified. Psychoses of schizophrenia spectrum were diagnosed in 52 patients, organic--in 8, alcoholic--in 7 and recurrent depressive disorder--in 2. Clinical significance of witchcraft delusions is closely related to its social aspect. Being combined with ideas of persecution, poisoning and damage, it results in the brutal forms of delusions defense and may be considered as an unfavorable prognostic trait.

  6. Immune Aspects of Female Infertility

    PubMed Central

    Brazdova, Andrea; Senechal, Helene; Peltre, Gabriel; Poncet, Pascal

    2016-01-01

    Immune infertility, in terms of reproductive failure, has become a serious health issue involving approximately 1 out of 5 couples at reproductive age. Semen that is defined as a complex fluid containing sperm, cellular vesicles and other cells and components, could sensitize the female genital tract. The immune rejection of male semen in the female reproductive tract is explained as the failure of natural tolerance leading to local and/or systemic immune response. Present active immune mechanism may induce high levels of anti-seminal/sperm antibodies. It has already been proven that iso-immunization is associated with infertility. Comprehensive studies with regards to the identification of antibody-targets and the determination of specific antibody class contribute to the development of effective immuno-therapy and, on the other hand, potential immuno-contraception, and then of course to complex patient diagnosis. This review summarizes the aspects of female immune infertility. PMID:27123194

  7. Scaling Aspects of Lymphocyte Trafficking

    PubMed Central

    Perelson, Alan S.; Wiegel, Frederik W.

    2010-01-01

    We consider the long lived pool of B and T cells that recirculate through blood, tissues and the lymphatic system of an animal with body mass M. We derive scaling rules (allometric relations) for: (1) the rate of production of mature lymphocytes; (2) the accumulation of lymphocytes in the tissues; (3) the flux of lymphocytes through the lymphatic system; (4) the number of lymph nodes, (5) the number of lymphocytes per clone within a lymph node, and (6) the total number of lymphocytes within a lymph node. Mass-dependent aspects of immune learning and of the immunological self are shown to be not very significant. Our treatment is somewhat heuristic and aims at a combination of immunological data with recent progress in biological scaling. PMID:19084024

  8. Sensory aspects of movement disorders.

    PubMed

    Patel, Neepa; Jankovic, Joseph; Hallett, Mark

    2014-01-01

    Movement disorders, which include disorders such as Parkinson's disease, dystonia, Tourette's syndrome, restless legs syndrome, and akathisia, have traditionally been considered to be disorders of impaired motor control resulting predominantly from dysfunction of the basal ganglia. This notion has been revised largely because of increasing recognition of associated behavioural, psychiatric, autonomic, and other non-motor symptoms. The sensory aspects of movement disorders include intrinsic sensory abnormalities and the effects of external sensory input on the underlying motor abnormality. The basal ganglia, cerebellum, thalamus, and their connections, coupled with altered sensory input, seem to play a key part in abnormal sensorimotor integration. However, more investigation into the phenomenology and physiological basis of sensory abnormalities, and about the role of the basal ganglia, cerebellum, and related structures in somatosensory processing, and its effect on motor control, is needed.

  9. Biomedical aspects of artificial gravity.

    PubMed

    Vil-Viliams, I F; Kotovskaya, A R; Shipov, A A

    1997-07-01

    Artificial gravity (AG) is the basic challenge for space biology and medicine. The importance of this problem is associated with the fact that duration of the space missions will become progressively longer, but the presently available countermeasures do not provide reason enough to predict the human health safety during space missions of any duration. The creation of AG could be an efficient method for removing the negative effects of microgravity. Two principle methods of generating AG, rotation of space system (SS) and building of short arm centrifuge (SAC), have been proposed. The purpose of the present work is to review the biomedical aspects of AG in the context of its use in long-term space missions.

  10. Discriminatory aspects of medical screening.

    PubMed

    Rothstein, M A

    1986-10-01

    Presently, there are few legal restrictions on the use of medical screening of workers. The Occupational Safety and Health Act (OSH Act) requires that certain medical tests be performed when workers will be exposed to specific toxic substances. The OSH Act does not, however, prohibit the use of any medical screening measure nor does it indicate what actions an employer may or may not take as a result of such information. (A notable exception is the medical removal provision of the Lead Standard). This paper discusses that protection afforded under Title VII of the Civil Rights Act of 1964, the Age Discrimination in Employment Act, and the Rehabilitation Act of 1973. This paper will demonstrate that the law has, in general, failed to take into account the discriminatory aspects of medical screening.

  11. Psychiatric Aspects of Organ Transplantation

    PubMed Central

    Kalra, G.; Desousa, A.

    2011-01-01

    Surgical transplantation of human organs from deceased as well as living donors to sick and dying patients began after the Second World War. Over the past 50 years the transplantation of human organs, tissues and cells has become a worldwide practice which has extended, and greatly enhanced the quality of hundreds of thousands of lives. The field of transplantation medicine provides an important chance for liaison between psychiatric professionals and other transplant physicians and surgeons. The discrepancy between the ever-increasing demand for organs but the decreasing supply makes it important to evaluate and prioritize individuals who are in dire need of the organ. However, this also gives rise to certain ethical questions. The following paper discusses various psychiatric aspects of organ transplantation in general. PMID:25013589

  12. Optical Coherence Tomography: Technical Aspects

    NASA Astrophysics Data System (ADS)

    Subhash, Hrebesh M.; Wang, Ruikang K.

    Optical coherence tomography (OCT) is a high-resolution, noninvasive, 3D imaging technique with great potential in both clinical and fundamental research applications in many areas. Owing to its exceptionally high spatial resolution and velocity sensitivity, the functional extension of OCT techniques can simultaneously provide tissue structure, blood perfusion, birefringence, and other physiological information and it has great potential for basic biomedical research and clinical medicine. OCT has the far-reaching potential to be a quantitative imaging technique that could impact many, as yet unexplored, areas and should therefore be considered a vital measurement tool. In this chapter, we will first discuss the principle of operation and then the practical aspects of the OCT system; we will also provide detailed discussion on different OCT schemes and its functional extensions.

  13. Sensory aspects of movement disorders

    PubMed Central

    Patel, Neepa; Jankovic, Joseph; Hallett, Mark

    2016-01-01

    Movement disorders, which include disorders such as Parkinson’s disease, dystonia, Tourette’s syndrome, restless legs syndrome, and akathisia, have traditionally been considered to be disorders of impaired motor control resulting predominantly from dysfunction of the basal ganglia. This notion has been revised largely because of increasing recognition of associated behavioural, psychiatric, autonomic, and other non-motor symptoms. The sensory aspects of movement disorders include intrinsic sensory abnormalities and the effects of external sensory input on the underlying motor abnormality. The basal ganglia, cerebellum, thalamus, and their connections, coupled with altered sensory input, seem to play a key part in abnormal sensorimotor integration. However, more investigation into the phenomenology and physiological basis of sensory abnormalities, and about the role of the basal ganglia, cerebellum, and related structures in somatosensory processing, and its effect on motor control, is needed. PMID:24331796

  14. [New aspects of tuberculosis therapy].

    PubMed

    Haegi, V

    1975-02-22

    The introduction of ethambutol and rifampicin has modified the therapy of tuberculosis. Therapy in hospitals or sanatoria can be shortened, and intermittent regimens (once or twice weekly under supervision) are possible. Better knowledge of the side effects of particular drugs, particularly rifampicin, (such as allergic reactions in intermittent administration and reduced effect of oral contraceptives) has been gained. Instead of mere supervision, preventive chemotherapy is given in many cases such as in recently discovered fibrotic lesions and in high risk cases (silicosis, treatment with corticosteroids and immunosuppressive agents)minadequate treatment may lead to functional impairment such as fibrosis and cor pulmonale. These aspects are discussed and the resultant guidelines for the treatment of tuberculosis are presented.

  15. Ergonomical aspects of anaesthetic practice

    PubMed Central

    Raghavendra Rao, RS

    2016-01-01

    Anaesthesiologist's service begins as a general physician, goes on as an investigator cum data analyser leading to the architectural planning of a forthcoming surgical event, but only after articulately convincing the subject along with his kith and kin. In the era of rapid developments in the field of medicine which includes relevant developments in anaesthetic care, an adequate work environment has to be provided to the anaesthesia team so that all anaesthetic procedures can be carried out safely and efficiently and an optimal workflow can be established in the operating room environment. Such ecological state demands an updated knowledge and ergonomics to aid him. Unfortunately, ergonomics is an area of anaesthesia that has received little attention and should be addressed through more education and training for workplace well-ness. Hence, an attempt is made to discuss few aspects on ergonomics for the interface between anaesthesiologist-machine-patient systems regarded as human-machine-system. PMID:27212716

  16. Numerical methods used in fusion science numerical modeling

    NASA Astrophysics Data System (ADS)

    Yagi, M.

    2015-04-01

    The dynamics of burning plasma is very complicated physics, which is dominated by multi-scale and multi-physics phenomena. To understand such phenomena, numerical simulations are indispensable. Fundamentals of numerical methods used in fusion science numerical modeling are briefly discussed in this paper. In addition, the parallelization technique such as open multi processing (OpenMP) and message passing interface (MPI) parallel programing are introduced and the loop-level parallelization is shown as an example.

  17. Potential and limits of numerical modelling for supporting the development of HTS devices

    NASA Astrophysics Data System (ADS)

    Sirois, Frédéric; Grilli, Francesco

    2015-04-01

    In this paper, we present a general review of the status of numerical modelling applied to the design of high temperature superconductor devices. The importance of this tool is emphasized at the beginning of the paper, followed by formal definitions of the notions of models, numerical methods and numerical models. The state-of-the-art models are listed, and the main limitations of existing numerical models are reported. Those limitations are shown to concern two aspects: on the one hand, the numerical performance (i.e. speed) of the methods themselves is not good enough yet; on the other hand, the availability of model file templates, material data and benchmark problems is clearly insufficient. Paths for improving those elements are indicated in the paper. Besides the technical aspects of the research to be further pursued, for instance in adaptive numerical methods, most recommendations command for an increased collective effort for sharing files, data, codes and their documentation.

  18. Numerical estimation of densities

    NASA Astrophysics Data System (ADS)

    Ascasibar, Y.; Binney, J.

    2005-01-01

    We present a novel technique, dubbed FIESTAS, to estimate the underlying density field from a discrete set of sample points in an arbitrary multidimensional space. FIESTAS assigns a volume to each point by means of a binary tree. Density is then computed by integrating over an adaptive kernel. As a first test, we construct several Monte Carlo realizations of a Hernquist profile and recover the particle density in both real and phase space. At a given point, Poisson noise causes the unsmoothed estimates to fluctuate by a factor of ~2 regardless of the number of particles. This spread can be reduced to about 1dex (~26 per cent) by our smoothing procedure. The density range over which the estimates are unbiased widens as the particle number increases. Our tests show that real-space densities obtained with an SPH kernel are significantly more biased than those yielded by FIESTAS. In phase space, about 10 times more particles are required in order to achieve a similar accuracy. As a second application we have estimated phase-space densities in a dark matter halo from a cosmological simulation. We confirm the results of Arad, Dekel & Klypin that the highest values of f are all associated with substructure rather than the main halo, and that the volume function v(f) ~f-2.5 over about four orders of magnitude in f. We show that a modified version of the toy model proposed by Arad et al. explains this result and suggests that the departures of v(f) from power-law form are not mere numerical artefacts. We conclude that our algorithm accurately measures the phase-space density up to the limit where discreteness effects render the simulation itself unreliable. Computationally, FIESTAS is orders of magnitude faster than the method based on Delaunay tessellation that Arad et al. employed, making it practicable to recover smoothed density estimates for sets of 109 points in six dimensions.

  19. Numerical investigation of the Taylor-Couette and Batchelor flows with heat transfer: physics and numerical modelling

    NASA Astrophysics Data System (ADS)

    Kiełczewski, K.; Tuliszka-Sznitko, E.; Bontoux, P.

    2014-08-01

    In the paper the authors present the results obtained during a numerical investigation (Direct Numerical Simulation/Spectral Vanishing Viscosity method - DNS/SVV) of a flow with heat transfer in rotating cavities (i.e. the flow between two concentric disks and two concentric cylinders). These model flows are useful from numerical and experimental point of view among others because of the simplicity of their geometry. Simultaneously, the flows in rotating cavities appear in numerous industrial installations and machines in the field of mechanics and chemistry, e.g., in ventilation installations, desalination tanks and waste water tanks, in cooling system, in gas turbines and axial compressors. In the paper attention is focused on the laminar-turbulent region in the configuration of the large aspect ratio i.e. Taylor-Couette flow (a Batchelor flow case of small aspect ratio Γ = 0.04 is also presented for comparison). The main purpose of computations is to investigate the influence of different parameters (the aspect ratio, the end-wall boundary conditions and temperature gradient) on the flow structure and flow characteristics. For the non-isothermal flow cases the Nusselt number distributions along cylinders are presented and are correlated with the flow structures. The λ2 method has been used for visualization.

  20. Evolution of cooling-channel properties for varying aspect ratio

    NASA Astrophysics Data System (ADS)

    Pizzarelli, M.; Nasuti, F.; Onofri, M.

    2016-07-01

    A trade-off analysis is performed on a cooling channel system representative of liquid rocket engine cooling systems. This analysis requires multiple cooling channel flow calculations which are performed by means of a proper numerical approach, referred to as quasi-two-dimensional (2D) model. This model, which is suited to high-aspect-ratio cooling channels (HARCC), permits to have a fast prediction of both the coolant flow evolution and the temperature distribution along the whole cooling channel structure. Before using the quasi-2D model for the trade-off analysis, its validation by comparison with computational fluid dynamics (CFD) results is presented and discussed. The results show that the pump power required to overcome losses in the cooling circuit can be minimized selecting a channel shaped with a suitably high aspect ratio.

  1. Biological Aspects of Computer Virology

    NASA Astrophysics Data System (ADS)

    Vlachos, Vasileios; Spinellis, Diomidis; Androutsellis-Theotokis, Stefanos

    Recent malware epidemics proved beyond any doubt that frightful predictions of fast-spreading worms have been well founded. While we can identify and neutralize many types of malicious code, often we are not able to do that in a timely enough manner to suppress its uncontrolled propagation. In this paper we discuss the decisive factors that affect the propagation of a worm and evaluate their effectiveness.

  2. Numerical simulation of platelet margination in microcirculation

    NASA Astrophysics Data System (ADS)

    Zhao, Hong; Shaqfeh, Eric

    2009-11-01

    The adhesion of platelets to vascular walls is the first step in clotting. This process critically depends on the preferential concentration of platelets near walls. The presence of red blood cells, which are the predominant blood constituents, is known to affect the steady state platelet concentration and the dynamic platelet margination, but the underlying mechanism is not well understood to-day. We use a direct numerical simulation to study the platelet margination process, with particular emphasis on the Stokesian hydrodynamic interactions among red cells, platelets, and vessel walls. Well-known mechanical models are used for the shearing and bending stiffness of red cell membranes, and the stiffer platelets are modeled as rigid discoids. A boundary integral formulation is used to solve the flow field, where the numerical solution procedure is accelerated by a parallel O(N N) smooth particle-mesh Ewald method. The effects of red cell hematocrit and deformability will be discussed.

  3. Pulmonary ultrastructure of the late aspects of human paraquat poisoning.

    PubMed Central

    Dearden, L. C.; Fairshter, R. D.; McRae, D. M.; Smith, W. R.; Glauser, F. L.; Wilson, A. F.

    1978-01-01

    The pulmonary ultrastructure of the late aspects of a case of human paraquat poisoning is investigated and compared with normal human pulmonary ultrastructure. Alveoli in the paraquat patient are numerically reduced in comparison to the control. They are filled with edematous proteinaceous plasma-like fluid containing erythrocytes, macrophages, leukocytes, fibroblast-like cells, platelets, and fibrin. These alveoli are lined by granular pneumocytes. Interstitial areas in the paraquat patient are greatly expanded and there are no alveolar septums. Interstitial areas contain proteinaceous plasma-like material, collagen, fibrin, platelets, mature fibroblasts, plasma cells, many leukocytes, numerous erythrocytes, and capillaries. Capillary permeability seems to be enhanced in the paraquat patient either by vesicles forming transendothelial channels or pores or by disruption of endothelial cells. Images Figure 1 Figure 2 Figures 3-7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:213978

  4. Simulating reionization in numerical cosmology

    NASA Astrophysics Data System (ADS)

    Sokasian, Aaron

    2003-11-01

    The incorporation of radiative transfer effects into cosmological hydrodynamical simulations is essential for understanding how the intergalactic medium (IGM) makes the transition from a neutral medium to one that is almost fully ionized. I present an approximate numerical method designed to study in a statistical sense how a cosmological density field is ionized by various sets of sources. The method requires relatively few time steps and can be employed with simulations of high resolution. First, I explore the reionization history of Helium II by z < 6 quasars. Comparisons between HeII opacities measured observationally and inferred from our analysis reveal that the uncertainties in the empirical luminosity function provide enough leeway to provide a satisfactory match. A property common to all the calculations is that the epoch of Helium II reionization must have occurred between 3≲z≲4 . I extend my analysis to study the constraints that can be placed on the nature of the cosmic ultraviolet (UV) background in the redshift interval 2.5≲z≲5 . I find that in order to simultaneously match observational estimates of the HI and HeII opacities, galaxies and quasars must contribute about equally to the ionizing background in HI at z ≃ 3. Moreover, my analysis requires the stellar component to rise for z > 3 to compensate for the declining contribution from bright quasars at higher redshift. To investigate how stellar source may have reionized the universe at z > 6, I have combined our 3D radiative transfer code with high resolution hydrodynamical simulations to study how population II and III type stars affected the reionization process. The resulting complex reionization histories are presented and comparisons made with observational constraints on the neutral fraction of hydrogen at z ˜ 6 derived from the z = 6.28 SDSS quasar of Becker and coworkers and the recent WMAP measurements of the electron scattering optical depth analysis of Kogut

  5. Drugs affecting the eye.

    PubMed

    Taylor, F

    1985-08-01

    This discussion reviews drugs that affect the eye, including antihyperglycemic agents; corticosteroids; antirheumatic drugs (quinolines, indomethacin, and allopurinol); psychiatric drugs (phenothiazine, thioridazine, and chlorpromazine); drugs used in cardiology (practolol, amiodarone, and digitalis gylcosides); drugs implicated in optic neuritis and atrophy, drugs with an anticholinergic action; oral contraceptives (OCs); and topical drugs and systemic effects. Refractive changes, either myopic or hypermetropic, can occur as a result of hyperglycemia, and variation in vision is sometimes a presenting symptom in diabetes mellitus. If it causes a change in the refraction, treatment of hyperglycemia almost always produces a temporary hypermetropia. A return to the original refractive state often takes weeks, sometimes months. There is some evidence that patients adequately treated with insulin improve more rapidly than those taking oral medication. Such patients always should be referred for opthalmological evaluation as other factors might be responsible, but it might not be possible to order the appropriate spectacle correction for some time. The most important ocular side effect of the systemic adiministration of corticosteroids is the formation of a posterior subcapsular cataract. Glaucoma also can result from corticosteroids, most often when they are applied topically. Corticosteroids have been implicated in the production of benign intracranial hypertension, which is paradoxical because they also are used in its treatment. The most important side effect of drugs such as chloroquine and hydroxychloroquine is an almost always irreversible maculopathy with resultant loss of central vision. Corneal and retinal changes similar to those caused by the quinolines have been reported with indomethacin, but there is some question about a cause and effect relationship. The National Registry of Drug Induced Ocular Side Effects in the US published 30 case histories of

  6. Kinesics of Affective Instability.

    ERIC Educational Resources Information Center

    Dil, Nasim

    1979-01-01

    Discusses the rationale of studying kinesics of affective instability, describes the phenonmenon of affective instability, examines the role of kinesics in the overall process of communication, and presents three case studies. (Author/AM)

  7. A Numerical/Experimental Study of Nitinol Actuator Springs

    NASA Astrophysics Data System (ADS)

    Auricchio, Ferdinando; Scalet, Giulia; Urbano, Marco

    2014-07-01

    This study deals with the numerical modeling, simulation and experimental analysis of shape-memory alloy (SMA) helicoidal springs. An experimental campaign is conducted on both SMA straight wires and helicoidal springs that experienced the same annealing process. Then, we use such experimental results to investigate three phenomenological constitutive models able to represent SMA macroscopic behavior. In particular, after the identification of all the material parameters from experimental results on SMA wires, we inspect the thermo-mechanical behavior of SMA helicoidal springs by comparing numerical predictions to experimental data. Finally, we discuss models capabilities and some aspects characterizing SMA material behavior.

  8. Numerical Study of Tip Vortex Flows

    NASA Technical Reports Server (NTRS)

    Dacles-Mariani, Jennifer; Hafez, Mohamed

    1998-01-01

    This paper presents an overview and summary of the many different research work related to tip vortex flows and wake/trailing vortices as applied to practical engineering problems. As a literature survey paper, it outlines relevant analytical, theoretical, experimental and computational study found in literature. It also discusses in brief some of the fundamental aspects of the physics and its complexities. An appendix is also included. The topics included in this paper are: 1) Analytical Vortices; 2) Experimental Studies; 3) Computational Studies; 4) Wake Vortex Control and Management; 5) Wake Modeling; 6) High-Lift Systems; 7) Issues in Numerical Studies; 8) Instabilities; 9) Related Topics; 10) Visualization Tools for Vertical Flows; 11) Further Work Needed; 12) Acknowledgements; 13) References; and 14) Appendix.

  9. Ricin Toxicity: Clinical and Molecular Aspects

    PubMed Central

    Moshiri, Mohammad; Hamid, Fatemeh; Etemad, Leila

    2016-01-01

    Seeds of the castor bean plant Ricinuscommunis L (CB) contain ricin toxin (RT), one of the most poisonous naturally-occurring substances known. Ricin toxin, a water-soluble glycoprotein that does not partition into the oil extract, is a ribosome-inactivating toxin composed of two chains, labeled A and B. Severity of the toxicity varies depending on the route of exposure to the toxin. Inhalational is the most toxic route, followed by oral ingestion. Orally-ingested RT accumulates in the liver and spleen but other cells are also affected. The main clinical manifestations are also related to the administration route. Oral ingestion of CB or RT results in abdominal pain, vomiting, diarrhea, and various types of gastrointestinal bleeding that leading to volume depletion, hypovolemic shock, and renal failure. Inhalation of the toxin presents with non-cardiogenic pulmonary edema, diffuse necrotizing pneumonia, interstitial and alveolar inflammation, and edema. Local injection of RT induces indurations at the injection site, swelling of regional lymph nodes, hypotension, and death. An enzyme-linked immunosorbent assay (ELISA) has been developed to detect RT in animal tissues and fluids. Ricinine, an alkaloid of CB, can be detected in rat urine within 48 h of RT exposure. Supportive care is the basic treatment and standard biowarfare decontamination protocols are used for RT intoxication. Dexamethasone and difluoromethylornithine might be effective treatments. This review examines the clinical and molecular aspects of ricin toxicity. PMID:27536698

  10. [Cystinuria update: clinical, biochemical and genetic aspects].

    PubMed

    Orts Costa, J A; Zúñiga Cabrera, A; Martínez de la Cára y Salmerón, J

    2003-06-01

    Cystinuria is an autosomal recessive disorder with an estimated incidence of 1 case in 7000 live births, that results in elevated urinary excretion of cystine and dibasic aminoacids: ornithine, lysine and arginine. Discussed by Sir Archibald Edward Garrod, in 1908, as one of the four first known inborn errors of metabolism, it is characterized by a defect in transport of cystine and dibasic aminoacids, that affects their reabsortion in both renal tubule and gastrointestinal tract. To date, according to the recent molecular findings, two genes have been identified as responsible for this disease: SLC3A1 and SLC7A9. A more accurate pheno/genotyping identification of cystinuric patients will allow to improve prophilaxis and therapy for this illness. Cystinuria only causes recurrent urolithiasis (about 1-2 / of renal calculi in adults) and its associated complications as clinical feature because of poor cystine solubility at low pH. An accurate control over prohylaxis (based on high water intake and potassium citrate treatment, on first line, and tiol-derivatives treatment, on second line) must be taken in patients -like homozygous type I- with high lithiasis risk. However, approximately one half of patients under prophylaxis control will develop recurrent lithiasis; in this case, only urology or surgical approaches would be possible. 474 Updated knowledge about biochemical, genetic, clinical, diagnosis, prevention, treatment and prognosis aspects of this, relatively unusual, disease has been reviewed in this article.

  11. Theoretical aspects of pollutant stress.

    PubMed

    Ballach, H J

    1998-01-01

    Symptoms of tree damage observed in Europe and overseas are often described as premature senescence. However, our own experiments with fumigated poplars have shown that the term premature senescence is misleading if undue emphasis is placed on features common to both normal and premature senescence. Consequently, the term should be replaced by a concrete description of the stress symptom noted, e.g. premature leaf loss or premature starch degradation. Such stress symptoms are usually unspecific - just like the mechanisms of stress avoidance or stress tolerance themselves. A stress model taking account of ecological, physiological and evolutionary aspects is presented; it is shown that the different stress phases are influenced by various factors, e.g. the photosynthetic capacity of the leaves. The stress reactions displayed by fumigated poplars serve as illustrations for this model. Different species of the genus Populus can be classified as more or less pure C-strategists. It is postulated that this group of plants, in particular, is disturbed by various stress parameters, such as air pollutants, if shoot growth or metabolite transport is impaired.

  12. Clinical aspects of phage therapy.

    PubMed

    Międzybrodzki, Ryszard; Borysowski, Jan; Weber-Dąbrowska, Beata; Fortuna, Wojciech; Letkiewicz, Sławomir; Szufnarowski, Krzysztof; Pawełczyk, Zdzisław; Rogóż, Paweł; Kłak, Marlena; Wojtasik, Elżbieta; Górski, Andrzej

    2012-01-01

    Phage therapy (PT) is a unique method of treatment of bacterial infections using bacteriophages (phages)-viruses that specifically kill bacteria, including their antibiotic-resistant strains. Over the last decade a marked increase in interest in the therapeutic use of phages has been observed, which has resulted from a substantial rise in the prevalence of antibiotic resistance of bacteria, coupled with an inadequate number of new antibiotics. The first, and so far the only, center of PT in the European Union is the Phage Therapy Unit (PTU) established at the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Wrocław, Poland in 2005. This center continues the rich tradition of PT in Poland, which dates from the early 1920s. The main objective of this chapter is to present a detailed retrospective analysis of the results of PT of 153 patients with a wide range of infections resistant to antibiotic therapy admitted for treatment at the PTU between January 2008 and December 2010. Analysis includes the evaluation of both the efficacy and the safety of PT. In general, data suggest that PT can provide good clinical results in a significant cohort of patients with otherwise untreatable chronic bacterial infections and is essentially well tolerated. In addition, the whole complex procedure employed to obtain and characterize therapeutic phage preparations, as well as ethical aspects of PT, is discussed.

  13. Breast Cancer 2012 - New Aspects.

    PubMed

    Kolberg, H-C; Lüftner, D; Lux, M P; Maass, N; Schütz, F; Fasching, P A; Fehm, T; Janni, W; Kümmel, S

    2012-07-01

    Treatment options as well as the characteristics for therapeutic decisions in patients with primary and advanced breast cancer are increasing in number and variety. New targeted therapies in combination with established chemotherapy schemes are broadening the spectrum, however potentially promising combinations do not always achieve a better result. New data from the field of pharmacogenomics point to prognostic and predictive factors that take not only the properties of the tumour but also inherited genetic properties of the patient into consideration. Current therapeutic decision-making is thus based on a combination of classical clinical and modern molecular biomarkers. Also health-economic aspects are more frequently being taken into consideration so that health-economic considerations may also play a part. This review is based on information from the recent annual congresses. The latest of these are the 34th San Antonio Breast Cancer Symposium 2011 and the ASCO Annual Meeting 2012. Among their highlights are the clinically significant results from the CLEOPATRA, BOLERO-2, EMILIA and SWOG S0226 trials on the therapy for metastatic breast cancer as well as further state-of-the-art data on the adjuvant use of bisphosphonates within the framework of the ABCSG-12, ZO-FAST, NSABP-B34 and GAIN trials.

  14. Aspects in grinding of ceramics

    SciTech Connect

    Cho, S.J.; Huh, Y.H.; Yoon, K.J. . Materials Evaluation Center); Ogawa, Tomeyoshi . Machining Group)

    1994-09-01

    Aspects in the grinding of ceramics have been investigated. Si[sub 3]N[sub 4], ZrO[sub 2], SiC, and Al[sub 2]O[sub 3] were ground with resin-bonded diamond wheels of grit numbers ranging from 80 to 800. Microstructural observations of ground surfaces show that grinding occurs predominantly by flow mode in Si[sub 3]N[sub 4] and ZrO[sub 2], and by fracture and grain pullout in SiC and Al[sub 2]O[sub 3]. The measurement of grinding force shows that grinding resistances in Si[sub 3]N[sub 4] and ZrO[sub 2] are significantly larger than those in SiC and Al[sub 2]O[sub 3]. As the grit number of the grinding wheel increases, maximum surface roughness significantly decreases in Si[sub 3]N[sub 4], ZrO[sub 2], and SiC, but it apparently does not change in Al[sub 2]O[sub 3]. This unexpected result in Al[sub 2]O[sub 3] is discussed in terms of the observed grinding mode and microstructure.

  15. Biological aspects of gender disorders.

    PubMed

    Corsello, S M; Di Donna, V; Senes, P; Luotto, V; Ricciato, M P; Paragliola, R M; Pontecorvi, A

    2011-12-01

    The scientific community is very interested in the biological aspects of gender disorders and sexual orientation. There are different levels to define an individual's sex: chromosomal, gonadic, and phenotypic sex. Concerning the psychological sex, men and women are different by virtue of their own gender identity, which means they recognize themselves as belonging to a determinate sex. They are different also as a result of their own role identity, a set of behaviors, tendencies, and cognitive and emotional attitudes, commonly defined as "male" and "female". Transsexuality is a disorder characterized by the development of a gender identity opposed to phenotypic sex, whereas homosexuality is not a disturbance of gender identity but only of sexual attraction, expressing sexual orientation towards people of the same sex. We started from a critical review of literature on genetic and hormonal mechanisms involved in sexual differentiation. We re-examined the neuro-anatomic and functional differences between men and women, with special reference to their role in psychosexual differentiation and to their possible implication in the genesis of homosexuality and identity gender disorders. Homosexuality and transsexuality are conditions without a well defined etiology. Although the influence of educational and environmental factors in humans is undeniable, it seems that organic neurohormonal prenatal and postnatal factors might contribute in a determinant way in the development of these two conditions. This "organicistic neurohormal theory" might find support in the study of particular situations in which the human fetus is exposed to an abnormal hormonal environment in utero.

  16. [Multiple sclerosis: current immunological aspects].

    PubMed

    Cuevas-García, Carlos

    2017-01-01

    Multiple sclerosis is the most common inflammatory, chronic and degenerative condition of the central nervous system, and represents the first cause of disability in young adults. In Mexico, 11 to 20 out of every 100 000 people suffer from this disease. The causes of multiple sclerosis remain unknown, but several theories have been proposed: the interaction of environmental factors, viral infectious factors and genetic and immune susceptibility of each individual patient, which induce an autoimmune response and promote neuronal/axonal degeneration. In this review, the immune reaction main components and neurodegeneration present in multiple sclerosis are analyzed, as well as the inflammatory cascade associated with demyelination. Available treatments' main purpose is to modulate aspects related to the adaptive immune response (B and T cells). The therapeutic challenge will be antigen-specific immune-tolerance induction, for example, with the use of tolerance protocols with peptides or DNA or nanoparticles vaccines. Future therapies should aim to control innate components (microglia, macrophages, astrocytes) and to promote remyelination. To optimize the treatment, a combined therapeutic approach targeting the control of inflammatory and neurodegenerative components of the disease and monitoring of biomarkers will be necessary.

  17. Fibromyalgia: clinical and occupational aspects.

    PubMed

    Helfenstein Jr, Milton; Goldenfum, Marco Aurélio; Siena, César Augusto Fávaro

    2012-01-01

    Fibromyalgia (FM) is a clinical syndrome commonly observed in daily medical practice and its etiopathogenesis is still unclear. As it is characterized by chronic musculoskeletal pain associated with several symptoms, FM may be confused with several other rheumatic and nonrheumatic diseases when they course with pictures of diffuse pain and chronic fatigue. FM treatment should be multidisciplinary, individualized, count on active participation of the patient, and based on combined pharmacological and nonpharmacological modalities. It is found both in work and non-work settings, and there is no scientific evidence in the literature showing that FM might be caused by occupation. FM seldom leads to incapacity to work. In cases where pain or fatigue do not respond to appropriate treatment, reaching significant levels, a short period away from work can be considered. As FM is a relevant subject, this review article was based on exploratory, qualitative, and bibliographic investigation, aiming to study the main clinical and occupational aspects of FM, emphasizing the theoretical-conceptual background and the experience of specialists.

  18. Metabolic aspects of bacterial persisters

    PubMed Central

    Prax, Marcel; Bertram, Ralph

    2014-01-01

    Persister cells form a multi-drug tolerant subpopulation within an isogenic culture of bacteria that are genetically susceptible to antibiotics. Studies with different Gram negative and Gram positive bacteria have identified a large number of genes associated with the persister state. In contrast, the revelation of persister metabolism has only been addressed recently. We here summarize metabolic aspects of persisters, which includes an overview about the bifunctional role of selected carbohydrates as both triggers for the exit from the drug tolerant state and metabolites which persisters feed on. Also alarmones as indicators for starvation have been shown to influence persister levels via different signaling cascades involving the activation of toxin-antitoxin systems and other regulatory factors. Finally, recent data obtained by 13C-isotopolog profiling demonstrated an active amino acid anabolism in Staphylococcus aureus cultures challenged with high drug concentrations. Understanding the metabolism of persister cells poses challenges but also paves the way for the development of anti-persister compounds. PMID:25374846

  19. Geometrical aspects of quantum spaces

    SciTech Connect

    Ho, Pei -Ming

    1996-05-11

    Various geometrical aspects of quantum spaces are presented showing the possibility of building physics on quantum spaces. In the first chapter the authors give the motivations for studying noncommutative geometry and also review the definition of a Hopf algebra and some general features of the differential geometry on quantum groups and quantum planes. In Chapter 2 and Chapter 3 the noncommutative version of differential calculus, integration and complex structure are established for the quantum sphere S12 and the quantum complex projective space CP{sub q}(N), on which there are quantum group symmetries that are represented nonlinearly, and are respected by all the aforementioned structures. The braiding of Sq2 and CPq(N) is also described. In Chapter 4 the quantum projective geometry over the quantum projective space CPq(N) is developed. Collinearity conditions, coplanarity conditions, intersections and anharmonic ratios is described. In Chapter 5 an algebraic formulation of Reimannian geometry on quantum spaces is presented where Riemannian metric, distance, Laplacian, connection, and curvature have their quantum counterparts. This attempt is also extended to complex manifolds. Examples include the quantum sphere, the complex quantum projective space and the two-sheeted space. The quantum group of general coordinate transformations on some quantum spaces is also given.

  20. Psychological aspects of peacekeeping operations

    PubMed Central

    Raju, M. S. V. K.

    2014-01-01

    Peacekeeping operations are but one aspect of the systems of peace that have evolved over the past seven decades in a world that is riven with violence of all kinds. With the end of cold war in the late eighties of the last century we have come to see much intrastate violence, in addition to usual interstate hostilities and war, arising out of religious, political, ethnic and economic differences between people. In the changed scenario peacekeeping operations have become complex politico-military-humanitarian efforts. A soldier, trained for conventional military operations, is obliged to participate in the unconventional operations of waging peace in alien lands often in volatile and violent situations and in the process he stands to get exposed to widely variable demands for adjustment that have the potential to bring to the fore many maladaptive responses. Peacekeeping operations also have the potential to offer opportunities for growth and resilience. India is a major player in peacekeeping activities for well over sixty years all over the world. It is necessary for the commanders and mental health professionals to understand the multifarious factors that impinge on the peacekeeping soldier's mind and the emerging patterns of responses thereof for effective management trained manpower and fulfillment of mission objectives PMID:25788805

  1. Key aspects of coronal heating

    PubMed Central

    Klimchuk, James A.

    2015-01-01

    We highlight 10 key aspects of coronal heating that must be understood before we can consider the problem to be solved. (1) All coronal heating is impulsive. (2) The details of coronal heating matter. (3) The corona is filled with elemental magnetic stands. (4) The corona is densely populated with current sheets. (5) The strands must reconnect to prevent an infinite build-up of stress. (6) Nanoflares repeat with different frequencies. (7) What is the characteristic magnitude of energy release? (8) What causes the collective behaviour responsible for loops? (9) What are the onset conditions for energy release? (10) Chromospheric nanoflares are not a primary source of coronal plasma. Significant progress in solving the coronal heating problem will require coordination of approaches: observational studies, field-aligned hydrodynamic simulations, large-scale and localized three-dimensional magnetohydrodynamic simulations, and possibly also kinetic simulations. There is a unique value to each of these approaches, and the community must strive to coordinate better. PMID:25897094

  2. Cosmological aspects of spontaneous baryogenesis

    SciTech Connect

    Simone, Andrea De; Kobayashi, Takeshi

    2016-08-24

    We investigate cosmological aspects of spontaneous baryogenesis driven by a scalar field, and present general constraints that are independent of the particle physics model. The relevant constraints are obtained by studying the backreaction of the produced baryons on the scalar field, the cosmological expansion history after baryogenesis, and the baryon isocurvature perturbations. We show that cosmological considerations alone provide powerful constraints, especially for the minimal scenario with a quadratic scalar potential. Intriguingly, we find that for a given inflation scale, the other parameters including the reheat temperature, decoupling temperature of the baryon violating interactions, and the mass and decay constant of the scalar are restricted to lie within ranges of at most a few orders of magnitude. We also discuss possible extensions to the minimal setup, and propose two ideas for evading constraints on isocurvature perturbations: one is to suppress the baryon isocurvature with nonquadratic scalar potentials, another is to compensate the baryon isocurvature with cold dark matter isocurvature by making the scalar survive until the present.

  3. [Psychophysiologic aspects of occupational flying].

    PubMed

    Lapa, V V

    1993-01-01

    The paper deals with advanced research on psychophysiology of flying activity to solve a triune task: to humanize the character and means of labour, to maintain a high level of working capacity and to develop professionally important psychophysiological features of flying personnel. The solution of the first task is associated with consecutive realization of the principle of actualization, an increase of psychophysiological capabilities of a man with the use of technical means in designing aeronautical engineering. Assurance of high functional reliability of flying personnel requires the development of the methods to evaluate and predict the state of psychophysiologic reserves during flying activities; the refinement of the norms of flight load on the basis of determining the quantitative interactions between a complexity level of flight assignments and a degree of decrease in reserve capabilities; the search for means and methods of correcting functional state directly in flight and accelerated recovery of performance postflight. The solution of psychophysiologic aspects of the professional reliability of pilot should be the development of a flight capabilities theory and theory-based improvement of estimation methods, development of methods and technical means for their improvements.

  4. Flower senescence: some molecular aspects.

    PubMed

    Shahri, Waseem; Tahir, Inayatullah

    2014-02-01

    Some molecular aspects of flower senescence have been reviewed. The isolation, identification and characterization of different genes from various flowers (mainly from petals) associated with senescence have been discussed. The isolated genes were divided into different groups. A large proportion of genes have been found to be upregulated during flower senescence while some genes were also found to be downregulated indicating that there exists a complex interplay between the expression patterns of various genes. The genes involved in petal expansion are found to be upregulated during normal flower development from anthesis to open flower stage, but XTH (Xyloglucan endotransglucosylase hydrolase) is found to be involved in petal expansion as well as abscission. Cysteine proteases or the genes encoding cysteine proteases (assigned a central role in protein degradation) have been identified from various flower systems, but no cysteine protease has been identified from senescing Mirabilis jalapa flowers. In addition to proteases, the genes encoding ubiquitin (exhibiting proteasomal degradation by 26S proteasomes) have also been identified suggesting the two alternate pathways for protein degradation. Genes encoding specific nucleases have also been identified, but they displayed an early increase in transcript abundance before the senescence symptoms become evident and characterize the involvement of PCD during flower senescence. A range of transcription factors are described and their possible role in flower senescence has been discussed. A detailed description of genes involved in ethylene synthesis and the components involved in ethylene signaling have been presented.

  5. Some Aspects of PDC Electrolysis

    NASA Astrophysics Data System (ADS)

    Poláčik, Ján; Pospíšil, Jiří

    2016-10-01

    In this paper, aspects of pulsed direct current (PDC) water splitting are described. Electrolysis is a simple and well-known method to produce hydrogen. The efficiency is relatively low in normal conditions using conventional DC. PDC in electrolysis brings about many advantages. It increases efficiency of hydrogen production, and performance of the electrolyser may be smoothly controlled without compromising efficiency of the process. In our approach, ultra-short pulses are applied. This method enhances efficiency of electrical energy in the process of decomposition of water into hydrogen and oxygen. Efficiency depends on frequency, shape and width of the electrical pulses. Experiments proved that efficiency was increased by 2 to 8 per cent. One of the prospects of PDC electrolysis producing hydrogen is in increase of efficiency of energy storage efficiency in the hydrogen. There are strong efforts to make the electrical grid more efficient and balanced in terms of production by installing electricity storage units. Using hydrogen as a fuel decreases air pollution and amount of carbon dioxide emissions in the air. In addition to energy storage, hydrogen is also important in transportation and chemical industry.

  6. Theoretical aspects of heterogeneous catalysis

    NASA Astrophysics Data System (ADS)

    Van Santen, R. A.

    Quantum chemical aspects of chemical bonding to metal surfaces are discussed. It is demonstrated that a Frontier Orbital Theory of chemisorption can be developed in which the group orbital local density of states at the Fermi level replaces the HOMO and LUMO interactions familiar in organic or organo-metallic chemistry. This appears to be a useful tool to describe elementary reactions at metal surfaces. Dissociation of the H2 molecule and hydrogen atom recombination is analysed in detail. Symmetry considerations can be applied. It is shown that the interaction with antisymmetric group orbitais lowers the activation energies. Such orbitais are also available at s-valence electron metal surfaces as long as the molecule interacts in bridging coordination sites. One finds that the interaction with metal d-valence electrons stabilizes coordination in the atop position. The relative contribution to bonding of metal s and d-valence electrons differs significantly for the transition metals. It is not only a function of metal-electron occupation, number, but also of the row in the periodic system in which the metal is placed. This information is used to explain the different hydrogenolysis behaviour of Ni and Pt.

  7. Psychosocial aspects of induced abortion.

    PubMed

    Stotland, N L

    1997-09-01

    US anti-abortion groups have used misinformation on the long-term psychological impact of induced abortion to advance their position. This article reviews the available research evidence on the definition, history, cultural context, and emotional and psychiatric sequelae of induced abortion. Notable has been a confusion of normative, transient reactions to unintended pregnancy and abortion (e.g., guilt, depression, anxiety) with serious mental disorders. Studies of the psychiatric aspects of abortion have been limited by methodological problems such as the impossibility of randomly assigning women to study and control groups, resistance to follow-up, and confounding variables. Among the factors that may impact on an unintended pregnancy and the decision to abort are ongoing or past psychiatric illness, poverty, social chaos, youth and immaturity, abandonment issues, ongoing domestic responsibilities, rape and incest, domestic violence, religion, and contraceptive failure. Among the risk factors for postabortion psychosocial difficulties are previous or concurrent psychiatric illness, coercion to abort, genetic or medical indications, lack of social supports, ambivalence, and increasing length of gestation. Overall, the literature indicates that serious psychiatric illness is at least 8 times more common among postpartum than among postabortion women. Abortion center staff should acknowledge that the termination of a pregnancy may be experienced as a loss even when it is a voluntary choice. Referrals should be offered to women who show great emotional distress, have had several previous abortions, or request psychiatric consultation.

  8. Hemodynamic aspects of Alzheimer's disease.

    PubMed

    Nagata, Ken; Sato, Mika; Satoh, Yuichi; Watahiki, Yasuhito; Kondoh, Yasushi; Sugawara, Maki; Box, Georgia; Wright, David; Leung, Sumie; Yuya, Hiromichi; Shimosegawa, Eku

    2002-11-01

    Neuroradiological functional imaging techniques demonstrate the patterns of hypoperfusion and hypometabolism that are thought to be useful in the differential diagnosis of Alzheimer's disease (AD) from other dementing disorders. Besides the distribution patterns of perfusion or energy metabolism, vascular transit time (VTT), vascular reactivity (VR), and oxygen extraction fraction (OEF), which can be measured with positron emission tomography (PET), provide hemodynamic aspects of brain pathophysiology. In order to evaluate the hemodynamic features of AD, PET studies were carried out in 20 patients with probable AD and 20 patients with vascular dementia (VaD). The PET findings were not included in their diagnostic process of AD. Using oxygen-15-labeled compounds, cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), OEF, cerebral blood volume, and VTT were measured quantitatively during resting state. To evaluate VR, CBF was also measured during CO(2) inhalation. There was a significant increase in OEF in and around the parietotemporal cortices, but both VTT and VR were well preserved in patients with AD. By contrast, VR was markedly depressed and VTT was mildly prolonged in patients with VaD. Thus, from the hemodynamic point of view, the preservation of vascular reserve may be a distinct difference between AD and VaD. Furthermore, this indicates a hemodynamic integrity of the vasculature in the level of arterioles in AD.

  9. Numerical Simulation in a Supercirtical CFB Boiler

    NASA Astrophysics Data System (ADS)

    Zhang, Yanjun; Gaol, Xiang; Luo, Zhongyang; Jiang, Xiaoguo

    The dimension of the hot circulation loop of the supercritical CFB boiler is large, and there are many unknowns and challenges that should be identified and resolved during the development. In order to realize a reasonable and reliable design of the hot circulation loop, numerical simulation of gas-solid flow in a supercritical CFB boiler was conducted by using FLUENT software. The working condition of hot circulation loop flow field, gas-solid flow affected by three unsymmetrical cyclones, air distribution and pressure drop in furnace were analyzed. The simulation results showed that the general arrangement of the 600MWe supercritical CFB boiler is reasonable.

  10. Green roof soil system affected by soil structural changes: A project initiation

    NASA Astrophysics Data System (ADS)

    Jelínková, Vladimíra; Dohnal, Michal; Šácha, Jan; Šebestová, Jana; Sněhota, Michal

    2014-05-01

    Anthropogenic soil systems and structures such as green roofs, permeable or grassed pavements comprise appreciable part of the urban watersheds and are considered to be beneficial regarding to numerous aspects (e.g. carbon dioxide cycle, microclimate, reducing solar absorbance and storm water). Expected performance of these systems is significantly affected by water and heat regimes that are primarily defined by technology and materials used for system construction, local climate condition, amount of precipitation, the orientation and type of the vegetation cover. The benefits and potencies of anthropogenic soil systems could be considerably threatened in case when exposed to structural changes of thin top soil layer in time. Extensive green roof together with experimental green roof segment was established and advanced automated monitoring system of micrometeorological variables was set-up at the experimental site of University Centre for Energy Efficient Buildings as an interdisciplinary research facility of the Czech Technical University in Prague. The key objectives of the project are (i) to characterize hydraulic and thermal properties of soil substrate studied, (ii) to establish seasonal dynamics of water and heat in selected soil systems from continuous monitoring of relevant variables, (iii) to detect structural changes with the use of X-ray Computed Tomography, (iv) to identify with the help of numerical modeling and acquired datasets how water and heat dynamics in anthropogenic soil systems are affected by soil structural changes. Achievements of the objectives will advance understanding of the anthropogenic soil systems behavior in conurbations with the temperate climate.

  11. Representing Cloud Processing of Aerosol in Numerical Models

    SciTech Connect

    Mechem, D.B.; Kogan, Y.L.

    2005-03-18

    The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the aerosol spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.

  12. Notes on the Heart: Affective Issues in the Writing Classroom.

    ERIC Educational Resources Information Center

    McLeod, Susan H.

    The most used model for empirical research on the writing process is based on cognitive psychology and does not take into account affective phenomena, although it has long been recognized that affect (that is, the noncognitive aspects of mental activity) plays a large role in writing and learning to write. To understand the complete picture, it is…

  13. Defining and Assessing Affective Outcomes in Undergraduate Pediatric Dentistry.

    ERIC Educational Resources Information Center

    Cullen, Claire L.

    1990-01-01

    The affective aspect of the curriculum is defined as the development of appropriate and measurable values such as ethical behavior, honesty, tolerance, and becoming a life-long learner. In outcome assessment of the affective category, the goal is to evaluate the transition of the student to a professional. (MLW)

  14. Numerical simulation of Bootstrap Current

    SciTech Connect

    Wu, Yanlin; White, R.B.

    1993-05-01

    The neoclassical theory of Bootstrap Current in toroidal systems is calculated in magnetic flux coordinates and confirmed by numerical simulation. The effects of magnetic ripple, loop voltage, and magnetic and electrostatic perturbations on bootstrap current for the cases of zero and finite plasma pressure are studied. The numerical results are in reasonable agreement with analytical estimates.

  15. Numerical simulation of dusty plasmas

    SciTech Connect

    Winske, D.

    1995-09-01

    The numerical simulation of physical processes in dusty plasmas is reviewed, with emphasis on recent results and unresolved issues. Three areas of research are discussed: grain charging, weak dust-plasma interactions, and strong dust-plasma interactions. For each area, we review the basic concepts that are tested by simulations, present some appropriate examples, and examine numerical issues associated with extending present work.

  16. Numerical Approaches to Spacetime Singularities.

    PubMed

    Berger, Beverly K

    1998-01-01

    This review updates a previous review article [22]. Numerical exploration of the properties of singularities could, in principle, yield detailed understanding of their nature in physically realistic cases. Examples of numerical investigations into the formation of naked singularities, critical behavior in collapse, passage through the Cauchy horizon, chaos of the Mixmaster singularity, and singularities in spatially inhomogeneous cosmologies are discussed.

  17. Aspects of the Solar Tachocline

    NASA Technical Reports Server (NTRS)

    Elliott, J. R.

    1997-01-01

    The splitting of the frequencies of p-mode multiplets enables information to be gained about the internal rotation of the sun. Such data have revealed a transition at the base of the convection zone from differential rotation similar to that observed at the surface to almost solid-body rotation in the radiative interior. This transition region, known as the tachocline, has been found to be relatively narrow and centered below the base of the convection zone. In this paper, the evolution of the transition region is investigated numerically. Without a large anisotropic viscosity, the depth to which it would spread in one solar age, under the assumption of a constant prescribed differential rotation at the base of the convection zone, is found to be greater than its extent as inferred from helioseismology. In the second part of the paper a highly anisotropic turbulent viscosity with a large horizontal component, as suggested by Spiegel & Zahn (1992), is assumed. In this case, a steady tachocline is formed in which the advection of angular momentum balances the Reynolds stresses. The horizontal component of turbulent viscosity required to match the thickness of the tachocline to that obtained by helioseismology, is estimated to be 5 x 1O sq cm/s The transport of helium is studied in this case and is found to yield a sound-speed increase similar to that required by helioseismology.

  18. Numerical Simulation of a Tornado Generating Supercell

    NASA Technical Reports Server (NTRS)

    Proctor, Fred H.; Ahmad, Nashat N.; LimonDuparcmeur, Fanny M.

    2012-01-01

    The development of tornadoes from a tornado generating supercell is investigated with a large eddy simulation weather model. Numerical simulations are initialized with a sounding representing the environment of a tornado producing supercell that affected North Carolina and Virginia during the Spring of 2011. The structure of the simulated storm was very similar to that of a classic supercell, and compared favorably to the storm that affected the vicinity of Raleigh, North Carolina. The presence of mid-level moisture was found to be important in determining whether a supercell would generate tornadoes. The simulations generated multiple tornadoes, including cyclonic-anticyclonic pairs. The structure and the evolution of these tornadoes are examined during their lifecycle.

  19. Family and social aspects of substance use disorders and treatment

    PubMed Central

    Daley, Dennis C.

    2014-01-01

    Substance use disorders (SUDs) are associated with numerous medical, psychiatric, psychological, spiritual, economic, social, family, and legal problems, creating a significant burden for affected individuals, their families, and society. This paper focuses on the effects of SUDs on family and social problems and emphasizes the need for clients in treatment to address these domains in their ongoing recovery. Individual, group, and family interventions to address these issues for clients with SUDs and their families are reviewed. PMID:25214748

  20. Lift augmentation via spanwise tip blowing - A numerical study

    NASA Technical Reports Server (NTRS)

    Childs, R. E.

    1986-01-01

    Numerical simulations of a low aspect ratio wing with and without a spanwise directed jet issuing from the wing tip have been performed. The results show that the tip vortex is displaced outward and upward by the blowing. This gives rise to a local lift augmentation mechanism, vortex lift caused by the vortex core being above the wing, and a global mechanism, the reduction of induced velocities due to greater apparent spin.

  1. Electrical Aspects of Impinging Flames

    NASA Astrophysics Data System (ADS)

    Chien, Yu-Chien

    This dissertation examines the use of electric fields as one mechanism for controlling combustion as flames are partially extinguished when impinging on nearby surfaces. Electrical aspects of flames, specifically, the production of chemi-ions in hydrocarbon flames and the use of convective flows driven by these ions, have been investigated in a wide range of applications in prior work but despite this fairly comprehensive effort to study electrical aspects of combustion, relatively little research has focused on electrical phenomena near flame extinguishment, nor for flames near impingement surfaces. Electrical impinging flames have complex properties under global influences of ion-driven winds and flow field disturbances from the impingement surface. Challenges of measurements when an electric field is applied in the system have limited an understanding of changes to the flame behavior and species concentrations caused by the field. This research initially characterizes the ability of high voltage power supplies to respond on sufficiently short time scales to permit real time electrical flame actuation. The study then characterizes the influence of an electric field on the impinging flame shape, ion current and flow field of the thermal plume associated with the flame. The more significant further examinations can be separated into two parts: 1) the potential for using electric fields to control the release of carbon monoxide (CO) from surface-impinging flames, and 2) an investigation of controlling electrically the heat transfer to a plate on which the flame impinges. Carbon monoxide (CO) results from the incomplete oxidation of hydrocarbon fuels and, while CO can be desirable in some syngas processes, it is usually a dangerous emission from forest fires, gas heaters, gas stoves, or furnaces where insufficient oxygen in the core reaction does not fully oxidize the fuel to carbon dioxide and water. Determining how carbon monoxide is released and how heat transfer

  2. Psychiatric aspects of Parkinson's disease

    PubMed Central

    Grover, Sandeep; Somaiya, Mansi; Kumar, Santhosh; Avasthi, Ajit

    2015-01-01

    Parkinson's disease (PD) is essentially characterized by the motor symptoms in the form of resting tremor, rigidity and bradykinesia. However, over the years it has been recognized that motor symptoms are just the “tip of the iceberg” of clinical manifestations of PD. Besides motor symptoms, PD characterized by many non-motor symptoms, which include cognitive decline, psychiatric disturbances (depression, psychosis and impulse control), sleep difficulties, autonomic failures (gastrointestinal, cardiovascular, urinary, thermoregulation) and pain syndrome. This review evaluates the various aspects of psychiatric disorders including cognitive decline and sleep disturbances in patients with PD. The prevalence rate of various psychiatric disorders is high in patients with PD. In terms of risk factors, various demographic, clinical and treatment-related variables have been shown to be associated with higher risk of development of psychiatric morbidity. Evidence also suggests that the presence of psychiatric morbidity is associated with poorer outcome. Randomized controlled trials, evaluating the various pharmacological and non-pharmacological treatments for management of psychiatric morbidity in patients with PD are meager. Available evidence suggests that tricyclic antidepressants like desipramine and nortriptyline are efficacious for management of depression. Among the antipsychotics, clozapine is considered to be the best choice for management of psychosis in patients with PD. Among the various cognitive enhancers, evidence suggest efficacy of rivastigmine in management of dementia in patients with PD. To conclude, this review suggests that psychiatric morbidity is highly prevalent in patients with PD. Hence, a multidisciplinary approach must be followed to improve the overall outcome of PD. Further studies are required to evaluate the efficacy of various other measures for management of psychiatric morbidity in patients with PD. PMID:25552854

  3. Aspects of topological string theory

    NASA Astrophysics Data System (ADS)

    Cook, Paul L. H.

    Two aspects of the topological string and its applications are considered in this thesis. Firstly, non-perturbative contributions to the OSV conjecture relating four-dimensional extremal black holes and the closed topological string partition function are studied. A new technique is formulated for encapsulating these contributions for the case of a Calabi-Yau manifold constructed by fibering two line bundle over a torus, with the unexpected property that the resulting non-perturbative completion of the topological string partition function is such that the black hole partition function is equal to a product of a chiral and an anti-chiral function. This new approach is considered both in the context of the requirement of background independence for the topological string, and for more general Calabi-Yau manifolds. Secondly, this thesis provides a microscopic derivation of the open topological string holomorphic anomaly equations proposed by Walcher in arXiv:0705.4098 under the assumption that open string moduli do not contribute. In doing so, however, new anomalies are found for compact Calabi-Yau manifolds when the disk one-point functions (string to boundary amplitudes) are non-zero. These new anomalies introduce coupling to wrong moduli (complex structure moduli in A-model and Kahler moduli in B-model), and spoil the recursive structure of the holomorphic anomaly equations. For vanishing disk one-point functions, the open string holomorphic anomaly equations can be integrated to solve for amplitudes recursively, using a Feynman diagram approach, for which a proof is presented.

  4. Direct Numerical Simulation of Automobile Cavity Tones

    NASA Technical Reports Server (NTRS)

    Kurbatskii, Konstantin; Tam, Christopher K. W.

    2000-01-01

    The Navier Stokes equation is solved computationally by the Dispersion-Relation-Preserving (DRP) scheme for the flow and acoustic fields associated with a laminar boundary layer flow over an automobile door cavity. In this work, the flow Reynolds number is restricted to R(sub delta*) < 3400; the range of Reynolds number for which laminar flow may be maintained. This investigation focuses on two aspects of the problem, namely, the effect of boundary layer thickness on the cavity tone frequency and intensity and the effect of the size of the computation domain on the accuracy of the numerical simulation. It is found that the tone frequency decreases with an increase in boundary layer thickness. When the boundary layer is thicker than a certain critical value, depending on the flow speed, no tone is emitted by the cavity. Computationally, solutions of aeroacoustics problems are known to be sensitive to the size of the computation domain. Numerical experiments indicate that the use of a small domain could result in normal mode type acoustic oscillations in the entire computation domain leading to an increase in tone frequency and intensity. When the computation domain is expanded so that the boundaries are at least one wavelength away from the noise source, the computed tone frequency and intensity are found to be computation domain size independent.

  5. The Beam Break-Up Numerical Simulator

    SciTech Connect

    Travish, G.A.

    1989-11-01

    Beam Break-Up (BBU) is a severe constraint in accelerator design, limiting beam current and quality. The control of BBU has become the focus of much research in the design of the next generation collider, recirculating and linear induction accelerators and advanced accelerators. Determining the effect on BBU of modifications to cavities, the focusing elements or the beam is frequently beyond the ability of current analytic models. A computer code was written to address this problem. The Beam Break-Up Numerical Simulator (BBUNS) was designed to numerically solve for beam break-up (BBU) due to an arbitrary transverse wakefield. BBUNS was developed to be as user friendly as possible on the Cray computer series. The user is able to control all aspects of input and output by using a single command file. In addition, the wakefield is specified by the user and read in as a table. The program can model energy variations along and within the beam, focusing magnetic field profiles can be specified, and the graphical output can be tailored. In this note we discuss BBUNS, its structure and application. Included are detailed instructions, examples and a sample session of BBUNS. This program is available for distribution. 50 refs., 18 figs., 5 tabs.

  6. Forensic aspects of alcohol abuse and homicide.

    PubMed

    Palijan, Tija Zarković; Kovacević, Drazen; Radeljak, Sanja; Kovac, Marina; Mustapić, Jelena

    2009-09-01

    Numerous investigations indicate a close link between violent behavior, homicide (murder) and alcohol intoxication. With increased frequency of drinking and the chronic consummation of alcohol, the risk of the fatal outcome or homicide and victimization caused by violence is more likely to occur. Studies conducted on convicted murderers suggested that about half of them were under the heavy influence of alcohol at the time of perpetration of murder. The sample in this survey consisted of 177 male offenders which committed criminal act of murder in Croatia from the year of 1990 until 2007 (capital murder and attempted murder). All were assigned for the forensic psychiatric evaluation by the Criminal Justice System (Court of Law) at the Department of Forensic Psychiatry, Neuropsychiatric Hospital, Popovaca, Croatia. For the purpose of this work the sample is divided in two groups of subjects: 1) offenders which were intoxicated at the time of murder and committed offence on intoxicated victim 2) offenders who were sober and committed offence on sober victims. Groups are compared according to the variables of crime and history of alcohol abuse. On the basis of obtained results we can conclude that there are significant differences in relation to the variables and modalities of criminal offence between two groups of offenders and victims. We could conclude that alcohol intoxication in offenders and victims at the time of murder could strongly affect the modalities of murder.

  7. General Aspects of Colorectal Cancer

    PubMed Central

    Centelles, Josep J.

    2012-01-01

    Colorectal cancer (CRC) is one of the main causes of death. Cancer is initiated by several DNA damages, affecting proto-oncogenes, tumour suppressor genes, and DNA repairing genes. The molecular origins of CRC are chromosome instability (CIN), microsatellite instability (MSI), and CpG island methylator phenotype (CIMP). A brief description of types of CRC cancer is presented, including sporadic CRC, hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndromes, familiar adenomatous polyposis (FAP), MYH-associated polyposis (MAP), Peutz-Jeghers syndrome (PJS), and juvenile polyposis syndrome (JPS). Some signalling systems for CRC are also described, including Wnt-β-catenin pathway, tyrosine kinase receptors pathway, TGF-β pathway, and Hedgehog pathway. Finally, this paper describes also some CRC treatments. PMID:23209942

  8. Evolutionary aspects of anxiety disorders

    PubMed Central

    Price, John S.

    2003-01-01

    Danger and harm are avoided by strategic decisions made at all three levels of the triune forebrain: rational (neomammalian), emotional (paleomammalian), and instinctive (reptilian). This applies also to potential harm from conspecifics, which leads to a choice between escalating and de-escalating strategies. Anxiety is a component of de-escalating strategies mediated by the paleomammalian and reptilian forebrains. When the neomammalian (rational) brain fails to deal with the threat of conspecific danger, these more primitive de-escalating strategies may be activated and may present as anxiety disorders. The capacity for concealment of anxiety and other forms of negative affect has also evolved, and excessive concealment may lead to psychopaihology by breaking the negative feedback loop of excessive motivation, leading to impaired performance, leading to signals of distress, and leading to reduced exhortation to succeed on the part of parents and teachers; this situation is illustrated by a model based on the Yerkes-Dodson law. PMID:22033473

  9. General aspects of colorectal cancer.

    PubMed

    Centelles, Josep J

    2012-01-01

    Colorectal cancer (CRC) is one of the main causes of death. Cancer is initiated by several DNA damages, affecting proto-oncogenes, tumour suppressor genes, and DNA repairing genes. The molecular origins of CRC are chromosome instability (CIN), microsatellite instability (MSI), and CpG island methylator phenotype (CIMP). A brief description of types of CRC cancer is presented, including sporadic CRC, hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndromes, familiar adenomatous polyposis (FAP), MYH-associated polyposis (MAP), Peutz-Jeghers syndrome (PJS), and juvenile polyposis syndrome (JPS). Some signalling systems for CRC are also described, including Wnt-β-catenin pathway, tyrosine kinase receptors pathway, TGF-β pathway, and Hedgehog pathway. Finally, this paper describes also some CRC treatments.

  10. Emerging aspects of Buruli ulcer.

    PubMed

    Thangaraj, Harry S; Phillips, Richard O; Evans, Mark R W; Wansbrough-Jones, Mark H

    2003-08-01

    Buruli ulcer, caused by the pathogen Mycobacterium ulcerans, is a major mycobacteriosis that affects people in scattered foci in the third world. It is amongst the most neglected of diseases in terms of primary healthcare strategies. However, this is changing as the World Health Organization launches a number of major global initiatives. Recent progress includes the unraveling of the genetic structure of the pathogen, examination of the mechanisms of virulence and the role of chemotherapy in disease treatment and prevention of recurrence, together with strategies aimed at reducing the economic burdens placed upon healthcare budgets of poorer nations. This review focuses upon the recent developments and the understanding of the disease, with particular focus on potential chemotherapy.

  11. Changing aspects of radiation enteropathy

    SciTech Connect

    Morgenstern, L.; Hart, M.; Lugo, D.; Friedman, N.B.

    1985-11-01

    Fifty-two patients with radiation enteropathy secondary to radiation for abdominal or pelvic malignant neoplasms are described. This series (1977 to 1984) is compared with a series of 50 patients from the same institution over an earlier period (1961 to 1977). Intestinal obstruction was the principal complication in both series; 96% of the patients underwent either intestinal resection or anastomotic bypass of the affected segment. Changes that have occurred since the last report are as follows: changes in source of radiation energy (linear accelerator); less evidence of mucosal damage; increased serosal reaction (''serosal peel''); and increased use of elemental diets, parenteral nutrition, and long intestinal tubes in surgical management. Since postoperative radiation injury occurs most frequently in the pelvis, new developments for the exclusion of small bowel from the pelvis during radiation are reviewed. Changes in fractionation of radiation dosage should also be considered in patients with enteric symptoms during radiation therapy.

  12. A model for roll stall and the inherent stability modes of low aspect ratio wings at low Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Shields, Matt

    The development of Micro Aerial Vehicles has been hindered by the poor understanding of the aerodynamic loading and stability and control properties of the low Reynolds number regime in which the inherent low aspect ratio (LAR) wings operate. This thesis experimentally evaluates the static and damping aerodynamic stability derivatives to provide a complete aerodynamic model for canonical flat plate wings of aspect ratios near unity at Reynolds numbers under 1 x 105. This permits the complete functionality of the aerodynamic forces and moments to be expressed and the equations of motion to solved, thereby identifying the inherent stability properties of the wing. This provides a basis for characterizing the stability of full vehicles. The influence of the tip vortices during sideslip perturbations is found to induce a loading condition referred to as roll stall, a significant roll moment created by the spanwise induced velocity asymmetry related to the displacement of the vortex cores relative to the wing. Roll stall is manifested by a linearly increasing roll moment with low to moderate angles of attack and a subsequent stall event similar to a lift polar; this behavior is not experienced by conventional (high aspect ratio) wings. The resulting large magnitude of the roll stability derivative, Cl,beta and lack of roll damping, Cl ,rho, create significant modal responses of the lateral state variables; a linear model used to evaluate these modes is shown to accurately reflect the solution obtained by numerically integrating the nonlinear equations. An unstable Dutch roll mode dominates the behavior of the wing for small perturbations from equilibrium, and in the presence of angle of attack oscillations a previously unconsidered coupled mode, referred to as roll resonance, is seen develop and drive the bank angle? away from equilibrium. Roll resonance requires a linear time variant (LTV) model to capture the behavior of the bank angle, which is attributed to the

  13. Comparative aspects of rodent and nonrodent animal models for mechanistic and translational diabetes research.

    PubMed

    Renner, Simone; Dobenecker, Britta; Blutke, Andreas; Zöls, Susanne; Wanke, Rüdiger; Ritzmann, Mathias; Wolf, Eckhard

    2016-07-01

    The prevalence of diabetes mellitus, which currently affects 387 million people worldwide, is permanently rising in both adults and adolescents. Despite numerous treatment options, diabetes mellitus is a progressive disease with severe comorbidities, such as nephropathy, neuropathy, and retinopathy, as well as cardiovascular disease. Therefore, animal models predictive of the efficacy and safety of novel compounds in humans are of great value to address the unmet need for improved therapeutics. Although rodent models provide important mechanistic insights, their predictive value for therapeutic outcomes in humans is limited. In recent years, the pig has gained importance for biomedical research because of its close similarity to human anatomy, physiology, size, and, in contrast to non-human primates, better ethical acceptance. In this review, anatomic, biochemical, physiological, and morphologic aspects relevant to diabetes research will be compared between different animal species, that is, mouse, rat, rabbit, pig, and non-human primates. The value of the pig as a model organism for diabetes research will be highlighted, and (dis)advantages of the currently available approaches for the generation of pig models exhibiting characteristics of metabolic syndrome or type 2 diabetes mellitus will be discussed.

  14. Working session 5: Operational aspects and risk analysis

    SciTech Connect

    Cizelj, L.; Donoghue, J.

    1997-02-01

    A general observation is that both operational aspects and risk analysis cannot be adequately discussed without information presented in other sessions. Some overlap of conclusions and recommendations is therefore to be expected. Further, it was assumed that recommendations concerning improvements in some related topics were generated by other sessions and are not repeated here. These include: (1) Knowledge on degradation mechanisms (initiation, progression, and failure). (2) Modeling of degradation (initiation, progression, and failure). (3) Capabilities of NDE methods. (4) Preventive maintenance and repair. One should note here, however, that all of these directly affect both operational and risk aspects of affected plants. A list of conclusions and recommendations is based on available presentations and discussions addressing risk and operational experience. The authors aimed at reaching as broad a consensus as possible. It should be noted here that there is no strict delineation between operational and safety aspects of degradation of steam generator tubes. This is caused by different risk perceptions in different countries/societies. The conclusions and recommendations were divided into four broad groups: human reliability; leakage monitoring; risk impact; and consequence assessment.

  15. Flying High: The Aeromedical Aspects of Marihuana

    DTIC Science & Technology

    A summary of the discussions from the Civil Aeromedical Institute Symposium on aeromedical aspects of marihuana is presented. The invited panel...discussed the legal aspects of marihuana use and aviation, the experiences of military aviation, and the acute and chronic effects of the drug. For civil...aviation, the panel proposed a 12-16 hour period between marihuana use and work in aviation, no radical changes in FAA policy towards marihuana use, and additional research on aeromedical aspects of marihuana .

  16. Numerical and Experimental Approaches Toward Understanding Lava Flow Heat Transfer

    NASA Astrophysics Data System (ADS)

    Rumpf, M.; Fagents, S. A.; Hamilton, C.; Crawford, I. A.

    2013-12-01

    We have performed numerical modeling and experimental studies to quantify the heat transfer from a lava flow into an underlying particulate substrate. This project was initially motivated by a desire to understand the transfer of heat from a lava flow into the lunar regolith. Ancient regolith deposits that have been protected by a lava flow may contain ancient solar wind, solar flare, and galactic cosmic ray products that can give insight into the history of our solar system, provided the records were not heated and destroyed by the overlying lava flow. In addition, lava-substrate interaction is an important aspect of lava fluid dynamics that requires consideration in lava emplacement models Our numerical model determines the depth to which the heat pulse will penetrate beneath a lava flow into the underlying substrate. Rigorous treatment of the temperature dependence of lava and substrate thermal conductivity and specific heat capacity, density, and latent heat release are imperative to an accurate model. Experiments were conducted to verify the numerical model. Experimental containers with interior dimensions of 20 x 20 x 25 cm were constructed from 1 inch thick calcium silicate sheeting. For initial experiments, boxes were packed with lunar regolith simulant (GSC-1) to a depth of 15 cm with thermocouples embedded at regular intervals. Basalt collected at Kilauea Volcano, HI, was melted in a gas forge and poured directly onto the simulant. Initial lava temperatures ranged from ~1200 to 1300 °C. The system was allowed to cool while internal temperatures were monitored by a thermocouple array and external temperatures were monitored by a Forward Looking Infrared (FLIR) video camera. Numerical simulations of the experiments elucidate the details of lava latent heat release and constrain the temperature-dependence of the thermal conductivity of the particulate substrate. The temperature-dependence of thermal conductivity of particulate material is not well known

  17. Incorporating Knowledge of Legal and Ethical Aspects into Computing Curricula of South African Universities

    ERIC Educational Resources Information Center

    Wayman, Ian; Kyobe, Michael

    2012-01-01

    As students in computing disciplines are introduced to modern information technologies, numerous unethical practices also escalate. With the increase in stringent legislations on use of IT, users of technology could easily be held liable for violation of this legislation. There is however lack of understanding of social aspects of computing, and…

  18. Systemic lupus erythematosus: Clinical and experimental aspects

    SciTech Connect

    Smolen, J.S.

    1987-01-01

    This text covers questions related to the history, etiology, pathogenesis, clinical aspects and therapy of systematic lupus erythematosus (SLE). Both animal models and human SLE are considered. With regard to basic science, concise information on cellular immunology, autoantibodies, viral aspects and molecular biology in SLE is provided. Clinical topics then deal with medical, dermatologic, neurologic, radiologic, pathologic, and therapeutic aspects. The book not only presents the most recent information on clinical and experimental insights, but also looks at future aspects related to the diagnosis and therapy of SLE.

  19. Food irradiation facilities: Requirements and technical aspects

    NASA Astrophysics Data System (ADS)

    Mittendorfer, Josef

    2016-12-01

    This survey presents some aspects and requirement for food irradiation facilities. Topics like radiation source, dose ranges and dose rate are discussed, together with logistics and operational considerations

  20. Effect of particle aspect ratio in magnetorheology

    NASA Astrophysics Data System (ADS)

    Morillas, Jose R.; Carreón-González, Elizabeth; de Vicente, Juan

    2015-12-01

    We investigate the influence of the aspect ratio of the dispersed particles in magnetorheology. Two systems are studied: conventional magnetorheological fluids prepared by dispersion of nickel nanowires, and inverse ferrofluids prepared by dispersion of glass fibers in a ferrofluid. In both cases the apparent yield stress is found to increase with aspect ratio in contradiction to available models in the literature. Experimental observations demonstrate that the particle volume fraction within the aggregates initially increases with increasing the aspect ratio of the dispersed particles. When the aspect ratio is further raised, a gel-like percolating structure forms inhibiting the formation of elongated clusters in the field direction.

  1. Numerical Hydrodynamics in General Relativity.

    PubMed

    Font, José A

    2000-01-01

    The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A representative sample of available numerical schemes is discussed and particular emphasis is paid to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of relevant astrophysical simulations in strong gravitational fields, including gravitational collapse, accretion onto black holes and evolution of neutron stars, is also presented.

  2. [Disease and contraception. Recent aspects].

    PubMed

    Rozenbaum, H

    1985-01-01

    copper IUDs do not have the bactericidal power formerly attributed to them. Numerous in vitro studies and statistical comparisons of the effect of spermicides in vivo have demonstrated that local methods provide protection against sexually transmitted diseases. OCs may favor vaginal infection, but some recent studies have indicated that they offer protection against pelvic infections. The protective effect of the condom against sexually transmitted diseases is well known. It has been estimated that, relative to non-users of OCs, each 100,000 users will have 235 fewer cases of benign breast disease, 35 fewer of ovarian cysts, 320 fewer of iron deficiency anemia, 600 fewer of pelivc infection, 117 fewer of extrauterine pregnancy, 32 fewer of rheumatoid arthritis, 1 fewer of endometrial cancer, and 3 fewer of ovarian cancer.

  3. Dean Flow Dynamics in Low-Aspect Ratio Spiral Microchannels

    PubMed Central

    Nivedita, Nivedita; Ligrani, Phillip; Papautsky, Ian

    2017-01-01

    A wide range of microfluidic cell-sorting devices has emerged in recent years, based on both passive and active methods of separation. Curvilinear channel geometries are often used in these systems due to presence of secondary flows, which can provide high throughput and sorting efficiency. Most of these devices are designed on the assumption of two counter rotating Dean vortices present in the curved rectangular channels and existing in the state of steady rotation and amplitude. In this work, we investigate these secondary flows in low aspect ratio spiral rectangular microchannels and define their development with respect to the channel aspect ratio and Dean number. This work is the first to experimentally and numerically investigate Dean flows in microchannels for Re > 100, and show presence of secondary Dean vortices beyond a critical Dean number. We further demonstrate the impact of these multiple vortices on particle and cell focusing. Ultimately, this work offers new insights into secondary flow instabilities for low-aspect ratio, spiral microchannels, with improved flow models for design of more precise and efficient microfluidic devices for applications such as cell sorting and micromixing. PMID:28281579

  4. Dean Flow Dynamics in Low-Aspect Ratio Spiral Microchannels

    NASA Astrophysics Data System (ADS)

    Nivedita, Nivedita; Ligrani, Phillip; Papautsky, Ian

    2017-03-01

    A wide range of microfluidic cell-sorting devices has emerged in recent years, based on both passive and active methods of separation. Curvilinear channel geometries are often used in these systems due to presence of secondary flows, which can provide high throughput and sorting efficiency. Most of these devices are designed on the assumption of two counter rotating Dean vortices present in the curved rectangular channels and existing in the state of steady rotation and amplitude. In this work, we investigate these secondary flows in low aspect ratio spiral rectangular microchannels and define their development with respect to the channel aspect ratio and Dean number. This work is the first to experimentally and numerically investigate Dean flows in microchannels for Re > 100, and show presence of secondary Dean vortices beyond a critical Dean number. We further demonstrate the impact of these multiple vortices on particle and cell focusing. Ultimately, this work offers new insights into secondary flow instabilities for low-aspect ratio, spiral microchannels, with improved flow models for design of more precise and efficient microfluidic devices for applications such as cell sorting and micromixing.

  5. [Molecular aspects of anthrax pathogenesis].

    PubMed

    Noskov, A N

    2014-01-01

    A model of anthrax infection with the role determined for main pathogenicity factors of Bacillus anthracis exotoxin and capsule is presented. After spore phagocytosis by macrophages, synthesis of the main exotoxin component begins - a protective antigen that in oligomeric form disrupts phagosome membrane. This accelerates the transition of the pathogen from phagosome into the macrophage cytoplasm. Poly-D-glutamine capsule synthesized by the pathogen triggers the exit (exocytosis) of vegetative cells from macrophages and protects them from re-phagocytosis in lymphatic node lumen. The vegetative cells, that actively and freely replicate in lymphatic node, secret an exotoxin that disrupts endothelial septum between lymph and blood due to cytotoxic activity. As a result the vegetative cells get into blood and bacteremia develops. Pathogenetic pattern during anthrax (multiple hemorrhages in various organs etc.) is associated with local microcirculation disorders of various organs caused by the effect of bacterial exoproteases via activation of Willebrand factor. This results in a rapid local increase of microbial mass and consequent powerful cytotoxic effect of exotoxin on the tissue cells of the affected organ. Death of the infected organism takes place at the final stage of infec- tion due to toxic shock caused by the exotoxin. A reduction of body temperature takes place after death and the process of spore formation begins in the dead animal: capsule depolymerization, chain shortening, peptidoglycan cortex formation. Spores in this form are the prolonged source of infectious agent conservation and spread of infection in nature.

  6. Biochemical aspects of Huntington's chorea.

    PubMed Central

    Caraceni, T; Calderini, G; Consolazione, A; Riva, E; Algeri, S; Girotti, F; Spreafico, R; Branciforti, A; Dall'olio, A; Morselli, P L

    1977-01-01

    Fifteen patients affected by Huntington's chorea were divided into two groups, 'slow' and 'fast', according to IQ scores on the Wechsler-Bellevue scale, and scores on some motor performance tests. A possible correlation was looked for between some biochemical data (cerebrospinal fluid (CSF), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5HIAA) levels, plasma dopamine-beta-hydroxylase (DBH), dopamine (DA) uptake by platelets), and clinical data (duration of illness, severity of symptoms, age of patients, IQ scores, 'slow' and 'fast' groups). The CSF, HVA, and 5HIAA levels were found to be significantly lowered in comparison with normal controls. DBH activity and DA uptake by platelets did not differ significantly from normal subjects. Treatment with haloperidol in all patients and with dipropylacetic acid in three patients did not appear to modify the CSF, HVA, and 5HIAA concentrations, the plasma DBH activity, or the DA uptake. There were no significant differences in the CSF, HVA, and 5HIAA contents between the two groups of patients, and there was no correlation between biochemical data and clinical features. PMID:143508

  7. Onychomycosis in Israel: epidemiological aspects.

    PubMed

    Segal, Rina; Shemer, Avner; Hochberg, Malca; Keness, Yoram; Shvarzman, Rima; Mandelblat, Marina; Frenkel, Michael; Segal, Esther

    2015-03-01

    Onychomycosis is a fungal infection treated orally for prolonged periods of treatment, caused primarily by Dermatophytes, Candida species and non-dermatophyte moulds (NDMs). The prevalence of specific aetiology may differ in dependence of environmental, geographic and demographic factors, and may affect management of the infection. The objective of this survey was to analyse epidemiologic parameters of onychomycosis in Israel. Data of a cohort of 27,093 patients were collected from six centres during a 2- and 10-year period. The diagnosis was based on microscopy of KOH/calcofluor mounts of nail scrapings and culture isolation. A positive result indicates isolation of a fungus in culture. Data were analysed for each centre and expressed as range for the whole cohort, using the spss v18 software. Analysis included three epidemiologic parameters: fungal aetiology in toe- and fingernails; association with gender; association with age group. Dermatophytes were the major causative agents and Trichophyton rubrum the most frequent isolate. Candida species were more frequent in women fingernails; frequency increased with age and C. parapsilosis the most frequent species. NDMs were isolated at low rate and Aspergillus terreus was the most frequent isolate. This is a first large cohort of onychomycosis patients from Israel analysed by defined epidemiological parameters.

  8. [Reproductive aspects of celiac disease].

    PubMed

    Stazi, Anna Velia; Trinti, Biagino

    2005-01-01

    In the past, celiac disease (CD), or intolerance to gluten, was considered a rare disease of infancy characterized by chronic diarrhea with malabsorption and delayed growth. Besides the overt enteropathy, there are other clinic and subclinical forms which appear later in life. Target organs are not limited to the gut, but include liver, thyroid, skin and female and male reproductive systems. CD interference on reproduction is related to the multifactorial nature of the disease, whose pathological manifestations can be modulated, besides gluten, by different concurrent genetic and environmental factors. CD induces malabsorption with consequent deficiencies of micronutrients such as iron, folic acid and vitamin K, which are essential for organogenesis, and fat-soluble vitamins important for spermatogenesis. Regarding endocrine disorders, the deficiencies of specific trace elements on ovarian function could explain its involvement in the increased risk of female osteoporosis in CD patients. Affected males show a picture of tissue resistance to androgens; the increases of follicle-stimulating hormone and prolactin, not associated with infertility, may indicate an imbalance at hypothalamus-pituitary level, with general effects on health. Since reproductive alterations are reversible, adoption of a gluten-free diet supported by early diagnosis is important. Therefore, the detection of early biomarkers, such as deficiencies of vitamins and/or iron and andrological or endocrinological dysfunctions, should trigger timely strategies for prevention and treatment.

  9. Exploring New Dimensions of Mathematics-Related Affect: Embodied and Social Theories

    ERIC Educational Resources Information Center

    Hannula, Markku S.

    2012-01-01

    This paper will review theoretical approaches for research on mathematics-related affect from the 1990s until today. In order to organise this field, a metatheory of the affective domain is developed, based on distinctions along three dimensions: 1) cognitive, motivational and emotional aspects of affect; 2) rapidly changing affective states…

  10. Alcohol and suicide: neurobiological and clinical aspects.

    PubMed

    Sher, Leo

    2006-06-21

    Alcohol, primarily in the form of ethyl alcohol (ethanol), has occupied an important place in the history of humankind for at least 8,000 years. In most Western societies, at least 90% of people consume alcohol at some time during their lives, and 30% or more of drinkers develop alcohol-related problems. Severe alcohol-related life impairment, alcohol dependence (alcoholism), is observed at some time during their lives in about 10% of men and 3-5% of women. An additional 5-10% of each sex develops persistent, but less intense, problems that are diagnosed as alcohol abuse. It this review, neurobiological aspects of suicidal behavior in alcoholism is discussed. In individuals with comorbid depression and alcoholism, greater serotonergic impairment may be associated with higher risk of completed suicide. Dopaminergic dysfunction may play an important role in the pathophysiology of suicidal behavior in alcoholism. Brain damage and neurobehavioral deficits are associated with alcohol use disorders and may contribute to suicidal behavior in persons with alcohol dependence or abuse. Aggression/impulsivity and alcoholism severity affect risk for suicide among individuals with alcoholism. Major depressive episodes and stressful life events particularly, partner-relationship disruptions, may precipitate suicidal behavior in individuals with alcohol use disorders. Alcohol misuse and psychosocial adversity can combine to increase stress on the person, and, thereby, potentially, increase the risk for suicidal behavior. The management of suicidal patients with alcohol use disorders is also discussed. It is to be hoped that the efforts of clinicians will reduce morbidity and mortality associated with alcohol misuse.

  11. Genus Paracoccidioides: Species Recognition and Biogeographic Aspects

    PubMed Central

    Theodoro, Raquel Cordeiro; Teixeira, Marcus de Melo; Felipe, Maria Sueli Soares; Paduan, Karina dos Santos; Ribolla, Paulo Martins; San-Blas, Gioconda; Bagagli, Eduardo

    2012-01-01

    Background Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3), and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. Methodology/Principal Findings Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3) were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE) analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11–32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. Conclusions/Significance The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides. PMID:22666382

  12. Numerical Simulation of Nix's Rotation

    NASA Video Gallery

    This is a numerical simulation of the orientation of Nix as seen from the center of the Pluto system. It has been sped up so that one orbit of Nix around Pluto takes 2 seconds instead of 25 days. L...

  13. Oral Allergy Syndrome (OAS). General and stomatological aspects.

    PubMed

    Ausukua, Martina; Dublin, Igone; Echebarria, Maria A; Aguirre, Jose M

    2009-11-01

    Oral Allergy Syndrome (OAS) is a special contact allergy conditioned by specific amino acids in food allergens, usually fruits, as well as some proteins from different pollens. It is usually manifested in the mouth, however relatively little is known about the syndrome in Odontology. OAS is a fairly common adverse reaction that occurs after ingesting certain foods, such as peaches or apples, produced in atopic individuals who usually suffer from rhinitis, bronchial asthma or both. This syndrome mainly affects the oral cavity and oropharynx, provoking minor local alterations, although there may be serious systematic reactions, making it important to distinguish it from other oral processes when making the diagnosis. One of the more severe forms of OAS is anaphylaxis, which is food-induced. In this study, we will analyze the key etiopathogenic, clinical and therapeutic aspects of this syndrome, focusing specifically on the stomatological aspects.

  14. Deformation mechanisms in negative Poisson's ratio materials - Structural aspects

    NASA Technical Reports Server (NTRS)

    Lakes, R.

    1991-01-01

    Poisson's ratio in materials is governed by the following aspects of the microstructure: the presence of rotational degrees of freedom, non-affine deformation kinematics, or anisotropic structure. Several structural models are examined. The non-affine kinematics are seen to be essential for the production of negative Poisson's ratios for isotropic materials containing central force linkages of positive stiffness. Non-central forces combined with pre-load can also give rise to a negative Poisson's ratio in isotropic materials. A chiral microstructure with non-central force interaction or non-affine deformation can also exhibit a negative Poisson's ratio. Toughness and damage resistance in these materials may be affected by the Poisson's ratio itself, as well as by generalized continuum aspects associated with the microstructure.

  15. Subjective Aspects of Cognitive Control at Different Stages of Processing

    PubMed Central

    Morsella, Ezequiel; Wilson, Lilian E.; Berger, Christopher C.; Honhongva, Mikaela; Gazzaley, Adam; Bargh, John A.

    2009-01-01

    While research on cognitive control has addressed the effects that different forms of cognitive interference have on behavior and the activities of certain brain regions, until recently scientific approaches have been silent regarding the effects of interference on subjective experience. We demonstrate that, at the level of the individual trial, participants can reliably introspect the subjective aspects (e.g., perceptions of difficulty, competition, and control) of responding in interference paradigms. Similar subjective effects were obtained for both expressed and unexpressed (subvocalized) actions. Few participants discerned the source of these effects. These basic findings illuminate aspects of cognitive control and cognitive effort. In addition, these data have implications for the study of response interference in affect and self-control, and they begin to address theories regarding the function of consciousness. PMID:19933564

  16. Numerical Investigation of the Dynamic Compressive Behaviour of Rock Materials at High Strain Rate

    NASA Astrophysics Data System (ADS)

    Hao, Y.; Hao, H.

    2013-03-01

    The dynamic compressive strength of rock materials increases with the strain rate. They are usually obtained by conducting laboratory tests such as split Hopkinson pressure bar (SHPB) test or drop-weight test. It is commonly agreed now that the dynamic increase factor (DIF) obtained from impact test is affected by lateral inertia confinement, friction confinement between the specimen and impact materials and the specimen sizes and geometries. Therefore, those derived directly from testing data do not necessarily reflect the true dynamic material properties. The influences of these parameters, however, are not straightforward to be quantified in laboratory tests. Therefore, the empirical DIF relations of rock materials obtained directly from impact tests consist of contributions from lateral inertia and end friction confinements, which need be eliminated to reflect the true dynamic material properties. Moreover, different rocks, such as granite, limestone and tuff have different material parameters, e.g., equation of state (EOS) and strength, which may also affect the DIF of materials but are not explicitly studied in the open literature. In the present study, numerical models of granite, limestone and tuff materials with different EOS and strength under impact loads are developed to simulate SHPB tests and to study the influences of EOS and strength, lateral inertia confinement and end friction confinement effects on their respective DIFs in the strain rate range between 1 and 1,000 s-1. The commercial software AUTODYN with user-provided subroutines is used to perform the numerical simulations of SHPB tests. Numerical simulation results indicate that the lateral inertia confinement, friction confinement and specimen aspect ( L/ D) ratio significantly influence DIF obtained from impact tests and the inertia confinement effect is different for different rocks. Based on the numerical results, quantifications on the relative contributions from the lateral inertia

  17. Numerical Approaches to Spacetime Singularities.

    PubMed

    Berger, Beverly K

    2002-01-01

    This Living Review updates a previous version [25] which is itself an update of a review article [31]. Numerical exploration of the properties of singularities could, in principle, yield detailed understanding of their nature in physically realistic cases. Examples of numerical investigations into the formation of naked singularities, critical behavior in collapse, passage through the Cauchy horizon, chaos of the Mixmaster singularity, and singularities in spatially inhomogeneous cosmologies are discussed.

  18. Numerical Optimization Using Computer Experiments

    NASA Technical Reports Server (NTRS)

    Trosset, Michael W.; Torczon, Virginia

    1997-01-01

    Engineering design optimization often gives rise to problems in which expensive objective functions are minimized by derivative-free methods. We propose a method for solving such problems that synthesizes ideas from the numerical optimization and computer experiment literatures. Our approach relies on kriging known function values to construct a sequence of surrogate models of the objective function that are used to guide a grid search for a minimizer. Results from numerical experiments on a standard test problem are presented.

  19. Numerical modeling of preburner flowfield

    NASA Astrophysics Data System (ADS)

    Chow, A. S.; Mo, J. D.; Jin, K. R.

    1993-06-01

    This work is intended to numerically predict the flowfields inside the preburner of the Space Shuttle Main Engine. The computer code (FDNS) based on pressure correction method is modified and adapted with an elliptic grid generator. The original configuration of the preburner in conjunction with downstream gas turbines has been simplified geometrically and numerically modeled at its full power in this work. The computational results are presented and qualitatively discussed with test data collected in NASA/MSFC.

  20. Forensic aspects of sexual harassment.

    PubMed

    Rosman, J P; McDonald, J J

    1999-03-01

    Sexual harassment law presents a complex set of issues not only for lawyers but also for psychiatrists in their roles both as evaluators and clinicians. Judge Reinhardt of the US Court of Appeals for the 9th Circuit, summed up these complexities: "We tend these days, far more than in earlier times, to find our friends, lovers, and even mates in the workplace. We ... often discover that our interests and values are closer to those of our colleagues or fellow employees than to those of people we meet in connection with other activities. In short, increased proximity breeds increased volitional sexual activity." On the other hand, he notes that Title VII "entitles individuals to a workplace that is free from the evil of sexual intimidation or repression. It is frequently difficult to reconcile the two competing values." He goes on to ask, "When does a healthy constructive interest in romance become sexual harassment? To what extent is pursuit of a co-worker proper but of a subordinate forbidden? Is wooing or courting a thing of the past? Must a suitor cease his attentions at the first sign of disinterest or resistance? Must there be an express agreement before the person seeking romance may even hold the hand of the subject of his affection? Is it now verboten to steal a kiss? In the workplace? Everywhere? Under all circumstances or only some? Has the art of romantic persuasion lost its charm? Questions relating to love and sex are among the most difficult for society to answer." The US Supreme Court has stressed the need for common sense in evaluating cases of sexual harassment. Perhaps psychiatrists can play a sobering role in developing answers to these questions.

  1. Grasping numbers: evidence for automatic influence of numerical magnitude on grip aperture.

    PubMed

    Namdar, Gal; Tzelgov, Joseph; Algom, Daniel; Ganel, Tzvi

    2014-06-01

    Previous research has shown that the fingers' aperture during grasp is affected by the numerical values of numbers embedded in the grasped objects: Numerically larger digits lead to larger grip apertures than do numerically smaller digits during the initial stages of the grasp. The relationship between numerical magnitude and visuomotor control has been taken to support the idea of a common underlying neural system mediating the processing of magnitude and the computation of object size for motor control. The purpose of the present study was to test whether the effect of magnitude on motor preparation is automatic. During grasping, we asked participants to attend to the colors of the digit while ignoring numerical magnitude. The results showed that numerical magnitude affected grip aperture during the initial stages of the grasp, even when magnitude information was irrelevant to the task at hand. These findings suggest that magnitude affects grasping preparation in an automatic fashion.

  2. Bidirectional Modulation of Numerical Magnitude.

    PubMed

    Arshad, Qadeer; Nigmatullina, Yuliya; Nigmatullin, Ramil; Asavarut, Paladd; Goga, Usman; Khan, Sarah; Sander, Kaija; Siddiqui, Shuaib; Roberts, R E; Cohen Kadosh, Roi; Bronstein, Adolfo M; Malhotra, Paresh A

    2016-05-01

    Numerical cognition is critical for modern life; however, the precise neural mechanisms underpinning numerical magnitude allocation in humans remain obscure. Based upon previous reports demonstrating the close behavioral and neuro-anatomical relationship between number allocation and spatial attention, we hypothesized that these systems would be subject to similar control mechanisms, namely dynamic interhemispheric competition. We employed a physiological paradigm, combining visual and vestibular stimulation, to induce interhemispheric conflict and subsequent unihemispheric inhibition, as confirmed by transcranial direct current stimulation (tDCS). This allowed us to demonstrate the first systematic bidirectional modulation of numerical magnitude toward either higher or lower numbers, independently of either eye movements or spatial attention mediated biases. We incorporated both our findings and those from the most widely accepted theoretical framework for numerical cognition to present a novel unifying computational model that describes how numerical magnitude allocation is subject to dynamic interhemispheric competition. That is, numerical allocation is continually updated in a contextual manner based upon relative magnitude, with the right hemisphere responsible for smaller magnitudes and the left hemisphere for larger magnitudes.

  3. Numerical anomalies mimicking physical effects

    SciTech Connect

    Menikoff, R.

    1995-09-01

    Numerical simulations of flows with shock waves typically use finite-difference shock-capturing algorithms. These algorithms give a shock a numerical width in order to generate the entropy increase that must occur across a shock wave. For algorithms in conservation form, steady-state shock waves are insensitive to the numerical dissipation because of the Hugoniot jump conditions. However, localized numerical errors occur when shock waves interact. Examples are the ``excess wall heating`` in the Noh problem (shock reflected from rigid wall), errors when a shock impacts a material interface or an abrupt change in mesh spacing, and the start-up error from initializing a shock as a discontinuity. This class of anomalies can be explained by the entropy generation that occurs in the transient flow when a shock profile is formed or changed. The entropy error is localized spatially but under mesh refinement does not decrease in magnitude. Similar effects have been observed in shock tube experiments with partly dispersed shock waves. In this case, the shock has a physical width due to a relaxation process. An entropy anomaly from a transient shock interaction is inherent in the structure of the conservation equations for fluid flow. The anomaly can be expected to occur whenever heat conduction can be neglected and a shock wave has a non-zero width, whether the width is physical or numerical. Thus, the numerical anomaly from an artificial shock width mimics a real physical effect.

  4. Bidirectional Modulation of Numerical Magnitude

    PubMed Central

    Arshad, Qadeer; Nigmatullina, Yuliya; Nigmatullin, Ramil; Asavarut, Paladd; Goga, Usman; Khan, Sarah; Sander, Kaija; Siddiqui, Shuaib; Roberts, R. E.; Cohen Kadosh, Roi; Bronstein, Adolfo M.; Malhotra, Paresh A.

    2016-01-01

    Numerical cognition is critical for modern life; however, the precise neural mechanisms underpinning numerical magnitude allocation in humans remain obscure. Based upon previous reports demonstrating the close behavioral and neuro-anatomical relationship between number allocation and spatial attention, we hypothesized that these systems would be subject to similar control mechanisms, namely dynamic interhemispheric competition. We employed a physiological paradigm, combining visual and vestibular stimulation, to induce interhemispheric conflict and subsequent unihemispheric inhibition, as confirmed by transcranial direct current stimulation (tDCS). This allowed us to demonstrate the first systematic bidirectional modulation of numerical magnitude toward either higher or lower numbers, independently of either eye movements or spatial attention mediated biases. We incorporated both our findings and those from the most widely accepted theoretical framework for numerical cognition to present a novel unifying computational model that describes how numerical magnitude allocation is subject to dynamic interhemispheric competition. That is, numerical allocation is continually updated in a contextual manner based upon relative magnitude, with the right hemisphere responsible for smaller magnitudes and the left hemisphere for larger magnitudes. PMID:26879093

  5. Preliminary Aspects of Language Course Evaluation

    ERIC Educational Resources Information Center

    Zohrabi, Mohammad

    2012-01-01

    Program and /or course evaluation is a process in which different types of data are collected systematically in order to study the virtues and weaknesses of a language instruction program. Program evaluation is, in fact, one of the essential aspects of any curriculum. It is a kind of quality control in which various aspects of an instructional…

  6. Preliminary Aspects of Language Course Evaluation

    ERIC Educational Resources Information Center

    Zohrabi, Mohammad

    2012-01-01

    Program and/or course evaluation is a process in which different types of data are collected systematically in order to study the virtues and weaknesses of a language instruction program. Program evaluation is, in fact, one of the essential aspects of any curriculum. It is a kind of quality control in which various aspects of an instructional…

  7. Some medical aspects of radionuclide intakes

    SciTech Connect

    Poda, G A

    1983-01-01

    In the field of medicine, particularly industrial medicine, the radiation aspect of the practice probably takes about 1/10 of 1% of our time. All the health physicist's tools of principles of internal dosimetry, lung models, mathematics, chemistry, etc. have little meaning until applied to an individual who has had an intake. This article discusses some of the medical aspects of internal dosimetry.

  8. [Legal aspects of psychiatry in Soviet legislation].

    PubMed

    Babayan, E A

    1977-01-01

    The Author examines and describes in detail the normative and organizational aspects of forensic-psychiatric services in the URSS. Both criminal expert opinions and civil aspects are described. The problem of civil rights of mentally ill persons are discussed together with education and training of the experts employed in institutions and by the courts.

  9. Key Aspects of Providing Healthcare Services in Disaster Response Stage

    PubMed Central

    POURHOSSEINI, Samira Sadat; ARDALAN, Ali; MEHROLHASSANI, Mohammad Hossien

    2015-01-01

    Abstract Background Health care management in disasters is one of the main parts of disaster management. Health in disasters is affected by performance of various sectors, and has an interactive impact on various aspects of disaster management. The aim of this study was to identify the most important themes affecting the healthcare management in disaster. Method In this qualitative study with a content analysis approach, in-depth interviews in two steps with 30 disaster experts and managers were conducted to collect the data. Results Eleven themes affecting healthcare management in disasters were identified. These themes were related to human resources management, resources management, victims’ management transfer, environmental hygiene monitoring, nutrition management, mental health control, inter-agency coordination, training, technology management, information and communication management, and budget management. Conclusion Providing effective health care service in disasters requires a comprehensive look at the various aspects of disaster management. Effective factors on the success of healthcare in disaster are not limited to the scope of healthcare. There should be a close relationship and interaction between different sectors of disaster management. PMID:26060782

  10. How Temporal and Spatial Aspects of Presenting Visualizations Affect Learning about Locomotion Patterns

    ERIC Educational Resources Information Center

    Imhof, Birgit; Scheiter, Katharina; Edelmann, Jorg; Gerjets, Peter

    2012-01-01

    Two studies investigated the effectiveness of dynamic and static visualizations for a perceptual learning task (locomotion pattern classification). In Study 1, seventy-five students viewed either dynamic, static-sequential, or static-simultaneous visualizations. For tasks of intermediate difficulty, dynamic visualizations led to better…

  11. Behavioural aspects of patients with Autism Spectrum Disorders (ASD) that affect their dental management

    PubMed Central

    Limeres-Posse, Jacobo; Castaño-Novoa, Patricia; Abeleira-Pazos, Maite; Ramos-Barbosa, Isabel

    2014-01-01

    Dental treatment in patients with Autism Spectrum Disorders (ASD) can be complicated due to the presence of behavioral alterations. In this group, there are no specific behavioral profiles that allow dentist to anticipate the attitude that a patient will show during a visit. Thus, behavioral attitudes have been described that vary from total permissiveness and collaboration during even bloody procedures, to the absolute impossibility in conducting a simple oral examination. There is no effective behavioral management technique for all ASD patients. Prior information, such as the type of ASD or the presence of certain concurrent pathologies can help predict the patient’s likely behavior. Therefore, gathering all the information in a preliminary interview with the parents/guardians of the patient is recommended. Knowing these factors will allow individualized behavioral management strategies to be designed and facilitates the planning of dental treatment. Key words:Dentistry, autism, ASD, behavior management. PMID:24608219

  12. Identifying Aspects of Parental Involvement that Affect the Academic Achievement of High School Students

    ERIC Educational Resources Information Center

    Roulette-McIntyre, Ovella; Bagaka's, Joshua G.; Drake, Daniel D.

    2005-01-01

    This study identified parental practices that relate positively to high school students' academic performance. Parents of 643 high school students participated in the study. Data analysis, using a multiple linear regression model, shows parent-school connection, student gender, and race are significant predictors of student academic performance.…

  13. Cognitive, Attitudinal, and Affective Aspects of Death and Dying in Adulthood: Implications For Care Providers.

    ERIC Educational Resources Information Center

    Educational Gerontology, 1981

    1981-01-01

    Assessed relationships among general anxiety, age, and measures of conscious and unconscious death anxiety in three groups of adult subjects varying in age and extent of contact with elderly persons. Data suggested that these relationships are complex, but that some degree of overlap exists among these factors. (Author)

  14. Behavioural aspects of patients with Autism Spectrum Disorders (ASD) that affect their dental management.

    PubMed

    Limeres-Posse, Jacobo; Castaño-Novoa, Patricia; Abeleira-Pazos, Maite; Ramos-Barbosa, Isabel

    2014-09-01

    Dental treatment in patients with Autism Spectrum Disorders (ASD) can be complicated due to the presence of behavioral alterations. In this group, there are no specific behavioral profiles that allow dentist to anticipate the attitude that a patient will show during a visit. Thus, behavioral attitudes have been described that vary from total permissiveness and collaboration during even bloody procedures, to the absolute impossibility in conducting a simple oral examination. There is no effective behavioral management technique for all ASD patients. Prior information, such as the type of ASD or the presence of certain concurrent pathologies can help predict the patient's likely behavior. Therefore, gathering all the information in a preliminary interview with the parents/guardians of the patient is recommended. Knowing these factors will allow individualized behavioral management strategies to be designed and facilitates the planning of dental treatment.

  15. Homogenization and Numerical Methods for Hyperbolic Equations

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Guo

    1990-01-01

    This dissertation studies three aspects of analysis and numerical methods for partial differential equations with oscillatory solutions. 1. Homogenization theory for certain linear hyperbolic equations is developed. We derive the homogenized convection equations for linear convection problems with rapidly varying velocity in space and time. We find that the oscillatory solutions are very sensitive to the arithmetic properties of certain parameters, such as the corresponding rotation number and the ratio between the components of the mean velocity field in linear convection. We also show that the oscillatory velocity field in two dimensional incompressible flow behaves like shear flows. 2. The homogenization of scalar nonlinear conservation laws in several space variables with oscillatory initial data is also discussed. We prove that the initial oscillations will be eliminated for any positive time when the equations are non-degenerate. This is also true for degenerate equations if there is enough mixing among the initial oscillations in the degenerate direction. Otherwise, the initial oscillation, for which the homogenized equation is obtained, will survive and be propagated. The large-time behavior of conservation laws with several space variables is studied. We show that, under a new nondegenerate condition (the second derivatives of the flux functions are linearly independent in any interval), a piecewise smooth periodic solution with converge strongly to the mean value of initial data. This generalizes Glimm and Lax's result for the one dimensional problem (3). 3. Numerical simulations of the oscillatory solutions are also carried out. We give some error estimate for varepsilon-h resonance ( varepsilon: oscillation wave length, h: numerical step) and prove essential convergence (24) of order alpha < 1 for some numerical schemes. These include upwind schemes and particle methods for linear hyperbolic equations with oscillatory coefficients. A stochastic analysis

  16. Static friction, differential algebraic systems and numerical stability

    NASA Astrophysics Data System (ADS)

    Chen, Jian; Schinner, Alexander; Matuttis, Hans-Georg

    We show how Differential Algebraic Systems (Ordinary Differential Equations with algebraic constraints) in mechanics are affected by stability issues and we implement Lubich's projection method to reduce the error to practically zero. Then, we explain how the "numerically exact" implementation for static friction by Differential Algebraic Systems can be stabilized. We conclude by comparing the corresponding steps in the "Contact mechanics" introduced by Moreau.

  17. The Effects of Physical Manipulatives on Children's Numerical Strategies

    ERIC Educational Resources Information Center

    Manches, Andrew; O'Malley, Claire

    2016-01-01

    This article focuses on how the representational properties of manipulatives affect the strategies children employ in problem solving. Two studies examined the effect of physical materials on 4-7-year-old children's problem solving strategies in a numerical (i.e., additive composition) task. The first study showed how children not only identified…

  18. [Affect and mimetic behavior].

    PubMed

    Zepf, S; Ullrich, B; Hartmann, S

    1998-05-01

    The relationship between facial expression and experienced affect presents many problems. The two diametrically opposed positions proposing solutions to this problem are exemplified using the conceptions of Mandler u. Izard. The underlying premises of both conceptions still prevail in various forms. The authors reject the concepts according to which facial expression is merely correlated to the affects (see Mandler 1975) as well as the view that facial expression controls the affects (see Izard 1977). The relationship between affect and facial expression is reexamined, subjecting it to a semiotic, essentially semantic analysis similar to the Ogden and Richards' language and meaning approach. This analysis involves a critical discussion of Scherer's attempt of a purely communicational interpretation using Bühler's organon model. In the author's approach, facial expression is seen not simply as a system of signals, but as a system of representative signs which signify the affects and refer to the emotive meaning of things for the subject. The authors develop the thesis that human beings are not born simply with the ability to speak, but also with the abstract possibility of performing facial expressions. This ability develops by way of coordinating patterns of expressions, which are presumably phylogenetically determined, with affects that take on a socially determined individual form, similar to language acquisition during socialisation. The authors discuss the methodological implications arising for studies investigating the affective meaning of facial expressions.

  19. Generation of large-scale structures and vortex systems in numerical experiments for rotating annular channels

    NASA Astrophysics Data System (ADS)

    Gledzer, A. E.

    2016-12-01

    Methods for solving shallow-water equations that describe flows in rotating annular channels are considered and the results of numerical calculations are analyzed for the possible generation of global large-scale flows, narrow jets, and numerous small-scale vortices in laboratory experiments. External effects in fluids are induced using a mass source-sink and the MHD-method of interaction of radial electric current with the magnetic field generated by the field of permanent magnets. A central-upwind scheme modified to suit the specific aspects of geophysical hydrodynamics. Initially, this method was used to solve shallow-water equations only in hydraulic problems, such as for flows in dam breaks, channels, rivers, and lakes. Geophysical hydrodynamics (in addition to free surface and topography) requires a rotation of the system as a whole, which is accompanied by the appearance of a complex system of vortices, jets, and turbulence (these should be taken into account in the formulation of the problem). Accordingly, the basic features of the central-upwind method should be changed. The modifications should ensure that the scheme is well-balanced and choose interpolation methods for desired variables. The main result of this modification is the control over numerical viscosity affecting the fluid motion variety. The active dynamics of a large number of vortices transformed into jets or generating large-scale streams is the general result of modifications suitable for geophysical hydrodynamics. Because there are technical difficulties in the creation of an appropriate laboratory setup for modeling of geophysical flows with the help of numerous source-sinks, it will be appropriate to use numerical experiments for studying the motions generated by this method. Unlike this method, the MHD-method can be rather easily used in laboratory conditions to generate a large variety of flows and vortex currents in the channel by a relatively small number of permanent magnets

  20. Numerical and experimental approaches to study soil transport and clogging in granular filters

    NASA Astrophysics Data System (ADS)

    Kanarska, Y.; Smith, J. J.; Ezzedine, S. M.; Lomov, I.; Glascoe, L. G.

    2012-12-01

    the soil transport in granular filters we investigated sensitivity of particle clogging mechanisms to various aspects such as particle size ration, the amplitude of hydraulic gradient, particle concentration and contact properties. By averaging the results derived from the grain-scale simulations, we investigated how those factors affect the semi-empirical multiphase model parameters in the large-scale simulation tool. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. The Department of Homeland Security Science and Technology Directorate provided funding for this research.

  1. The ART approach: clinical aspects reviewed.

    PubMed

    Molina, Gustavo Fabián; Cabral, Ricardo Juan; Frencken, Jo E

    2009-01-01

    The success of ART as a caries management approach is supported by more than 20 years of scientific evidence. ART follows the contemporary concepts of modern cariology and restorative dentistry. It challenges treatment concepts such as step-wise excavation and the need for complete removal of affected dentine. The ART approach so far has mainly used high-viscosity glass-ionomer as the sealant and restorative material. Cariostatic and remineralization properties have been ascribed to this material which requires further research to establish its clinical relevance. The adhesion of high-viscosity glass-ionomer to enamel in pits and fissures is apparently strong, as its remnants, blocking the pits and fissures, have been considered a possible reason for the low prevalence of carious lesion development after the glass-ionomer has clinically disappeared from it. Encapsulated high-viscosity glass-ionomers may lead to higher restoration survival results than those of the hand-mixed version and should, therefore, not be neglected when using ART. Similarly, the use of resin-modified glass-ionomer with ART should be researched. The effectiveness of ART when compared to conventional caries management approaches has been shown in numerous studies. Proper case selection is an important factor for long-lasting ART restoration survival. This is based on the caries risk situation of the individual, the size of the cavity opening, the strategic position of the cavitated tooth and the presence of adequate caries control measures. As the operator is one of the main causes for failure of ART restorations, attending a well-conducted ART training course is mandatory for successful implementation of ART.

  2. Flow visualization study in high aspect ratio cooling channels for rocket engines

    NASA Technical Reports Server (NTRS)

    Meyer, Michael L.; Giuliani, James E.

    1993-01-01

    geometry. The fluid dynamic and conjugate heat transfer problem of high aspect ratio rocket engine coolant channels are being investigated numerically, but these efforts have been hampered by a lack of validating data. Wall temperature data is available for the conjugate problem for channels without curvature and aspect ratio = 5.0, and unheated fluid dynamic data are available for square and circular cross section channels with curvature at Reynold's numbers up to 40,000. But the effects of aspect ratio on secondary flow development have not been experimentally studied. To provide some insight into the effects of channel aspect ratio on secondary flow and to qualitatively provide anchoring for the numerical codes, a flow visualization experiment was initiated at the NASA Lewis Research Center.

  3. Mycorrhizal aspects in slope stabilisation

    NASA Astrophysics Data System (ADS)

    Graf, Frank

    2016-04-01

    In order to re-colonise and stabilise slopes affected by superficial soil failure with plants essential requirements have to be met: the plants must grow the plants must survive sustainably plant succession must start and continuously develop These requirements, however, are anything but easy given, particularly under the often hostile environmental conditions dominating on bare and steep slopes. Mycorrhizal fungi, the symbiotic partners of almost all plants used in eco-engineering, are said to improve the plants' ability to overcome periods governed by strongly (growth) limiting factors. Subsequently, results of investigations are presented of mycorrhizal effects on different plant and soil functions related to eco-engineering in general and soil and slope stabilisation in particular. Generally, inoculation yielded higher biomass of the host plants above as well as below ground. Furthermore, the survival rate was higher for mycorrhized compared to non-mycorrhized plants, particularly under extreme environmental conditions. However, the scale of the mycorrhizal impact may be species specific of both the plant host as well as the fungal partner(s) and often becomes evident only after a certain time lag. Depending on the plant-fungus combination the root length per soil volume was found to be between 0 and 2.5 times higher for inoculated compared to non-inoculated specimens. On an alpine graded ski slope the survival of inoculated compared to non-treated Salix herbacea cuttings was significant after one vegetation period only for one of the three added mycorrhizal fungus species. However, after three years all of the inoculated plantlets performed significantly better than the non-inoculated controls. The analysis of the potential for producing and stabilising soil aggregates of five different ectomycorrhizal fungi showed high variation and, for the species Inocybe lacera, no significant difference compared to untreated soil. Furthermore, inoculation of Salix

  4. [Medicolegal aspects of driving ability and discussion of study methods].

    PubMed

    Berghaus, G

    2008-06-01

    Medicolegal aspects of driving ability primarily concern patients themselves, because they are responsible when driving in traffic while under drug treatment. Pain patients taking analgesic medication prescribed by a doctor do not commit an offence, insofar as they are able to drive. A doctor's main duty consists of informing the patient about the way a given disease or drug intake affects driving ability. Patients have the duty to inform themselves about the drug they are taking and to assess their driving ability each time before they drive a car.

  5. Compounds affecting cholesterol absorption

    NASA Technical Reports Server (NTRS)

    Hua, Duy H. (Inventor); Koo, Sung I. (Inventor); Noh, Sang K. (Inventor)

    2004-01-01

    A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof.

  6. Minnowbrook IV: 2003 Workshop on Transition and Unsteady Aspects of Turbomachinery Flows

    NASA Technical Reports Server (NTRS)

    LaGraff, John E. (Editor); Ashpis, David E.

    2004-01-01

    This Minnowbrook IV 2003 workshop on Transition and Unsteady Aspects of Turbomachinery Flows includes the following topics: 1) Current Issues in Unsteady Turbomachinery Flows; 2) Global Instability and Control of Low-Pressure Turbine Flows; 3) Influence of End Wall Leakage on Secondary Flow Development in Axial Turbines; 4) Active and Passive Flow Control on Low Pressure Turbine Airfoils; 5) Experimental and Numerical Investigation of Transitional Flows as Affected by Passing Wakes; 6) Effects of Freestream Turbulence on Turbine Blade Heat Transfer; 7) Bypass Transition Via Continuous Modes and Unsteady Effects on Film Cooling; 8) High Frequency Surface Heat Flux Imaging of Bypass Transition; 9) Skin Friction and Heat Flux Oscillations in Upstream Moving Wave Packets; 10) Transition Mechanisms and Use of Surface Roughness to Enhance the Benefits of Wake Passing in LP Turbines; 11) Transient Growth Approach to Roughness-Induced Transition; 12) Roughness- and Freestream-Turbulence-Induced Transient Growth as a Bypass Transition Mechanism; 13) Receptivity Calculations as a Means to Predicting Transition; 14) On Streamwise Vortices in a Curved Wall Jet and Their Effect on the Mean Flow; 15) Plasma Actuators for Separation Control of Low Pressure Turbine Blades; 16) Boundary-Layer Separation Control Under Low-Pressure-Turbine Conditions Using Glow-Discharge Plasma Actuators; 17) Control of Separation for Low Pressure Turbine Blades: Numerical Simulation; 18) Effects of Elevated Free-Stream Turbulence on Active Control of a Separation Bubble; 19) Wakes, Calming and Transition Under Strong Adverse Pressure Gradients; 20) Transitional Bubble in Periodic Flow Phase Shift; 21) Modelling Spots: The Calmed Region, Pressure Gradient Effects and Background; 22) Modeling of Unsteady Transitional Flow on Axial Compressor Blades; 23) Challenges in Predicting Component Efficiencies in Turbomachines With Low Reynolds Number Blading; 24) Observations on the Causal Relationship Between

  7. Numeral Incorporation in Japanese Sign Language

    ERIC Educational Resources Information Center

    Ktejik, Mish

    2013-01-01

    This article explores the morphological process of numeral incorporation in Japanese Sign Language. Numeral incorporation is defined and the available research on numeral incorporation in signed language is discussed. The numeral signs in Japanese Sign Language are then introduced and followed by an explanation of the numeral morphemes which are…

  8. Comparing Happiness and Hypomania Risk: A Study of Extraversion and Neuroticism Aspects.

    PubMed

    Kirkland, Tabitha; Gruber, June; Cunningham, William A

    2015-01-01

    Positive affect has long been considered a hallmark of subjective happiness. Yet, high levels of positive affect have also been linked with hypomania risk: a set of cognitive, affective, and behavioral characteristics that constitute a dispositional risk for future episodes of hypomania and mania. At a personality level, two powerful predictors of affective experience are extraversion and neuroticism: extraversion has been linked to positive affect, and neuroticism to negative affect. As such, a single personality trait--extraversion--has been linked to both beneficial and harmful outcomes associated with positivity. It is clear that positive affect, in different forms, has divergent consequences for well-being, but previous research has struggled to articulate the nature of these differences. We suggest that the relationship between affect and well-being needs to be situated within the psychological context of the individual--both in terms of more specific forms of extraversion and neuroticism, but also in terms of interactions among personality aspects. Consistent with this idea, we found that two aspects of extraversion (enthusiasm and assertiveness) differentially predicted subjective happiness from hypomania risk and two aspects of neuroticism (volatility and withdrawal) interacted to predict hypomania risk: the highest levels of hypomania risk were associated with the combination of high volatility and low withdrawal. These findings underscore the importance of examining personality at the right level of resolution to understand well-being and dysfunction.

  9. Inhomogeneous cosmology with numerical relativity

    NASA Astrophysics Data System (ADS)

    Macpherson, Hayley J.; Lasky, Paul D.; Price, Daniel J.

    2017-03-01

    We perform three-dimensional numerical relativity simulations of homogeneous and inhomogeneous expanding spacetimes, with a view toward quantifying nonlinear effects from cosmological inhomogeneities. We demonstrate fourth-order convergence with errors less than one part in 1 06 in evolving a flat, dust Friedmann-Lemaître-Roberston-Walker spacetime using the Einstein Toolkit within the Cactus framework. We also demonstrate agreement to within one part in 1 03 between the numerical relativity solution and the linear solution for density, velocity and metric perturbations in the Hubble flow over a factor of ˜350 change in scale factor (redshift). We simulate the growth of linear perturbations into the nonlinear regime, where effects such as gravitational slip and tensor perturbations appear. We therefore show that numerical relativity is a viable tool for investigating nonlinear effects in cosmology.

  10. A numerical method of regenerator

    NASA Astrophysics Data System (ADS)

    Zhu, Shaowei; Matsubara, Yoichi

    2004-02-01

    A numerical method for regenerators is introduced in this paper. It is not only suitable for the regenerators in cryocoolers and Stirling engines, but also suitable for the stacks in acoustic engines and the pulse tubes in pulse tube refrigerators. The numerical model is one dimensional periodic unsteady flow model. The numerical method is based on the control volume concept with the implicitly solve method. The iteration acceleration method, which considers the one-dimensional periodic unsteady problem as the steady two-dimensional problem, is used for decreasing the calculation time. By this method, the regenerator in an inertance tube pulse tube refrigerator was simulated. The result is useful for understanding how the inefficiency of the regenerator changes with the inertance effect.

  11. Numerical Simulation of Black Holes

    NASA Astrophysics Data System (ADS)

    Teukolsky, Saul

    2003-04-01

    Einstein's equations of general relativity are prime candidates for numerical solution on supercomputers. There is some urgency in being able to carry out such simulations: Large-scale gravitational wave detectors are now coming on line, and the most important expected signals cannot be predicted except numerically. Problems involving black holes are perhaps the most interesting, yet also particularly challenging computationally. One difficulty is that inside a black hole there is a physical singularity that cannot be part of the computational domain. A second difficulty is the disparity in length scales between the size of the black hole and the wavelength of the gravitational radiation emitted. A third difficulty is that all existing methods of evolving black holes in three spatial dimensions are plagued by instabilities that prohibit long-term evolution. I will describe the ideas that are being introduced in numerical relativity to deal with these problems, and discuss the results of recent calculations of black hole collisions.

  12. Numerical Package in Computer Supported Numeric Analysis Teaching

    ERIC Educational Resources Information Center

    Tezer, Murat

    2007-01-01

    At universities in the faculties of Engineering, Sciences, Business and Economics together with higher education in Computing, it is stated that because of the difficulty, calculators and computers can be used in Numerical Analysis (NA). In this study, the learning computer supported NA will be discussed together with important usage of the…

  13. Energy Aspects of Green Buildings - International Experience

    NASA Astrophysics Data System (ADS)

    Kauskale, L.; Geipele, I.; Zeltins, N.; Lecis, I.

    2016-12-01

    At present, reduction of greenhouse gas emissions is one of the main environmental priorities globally, and implementation of sustainability aspects in the construction industry, including energy aspects, is of major importance for long-term environmental development, as buildings have a long life cycle and require many resources both for construction and operation periods. The aim of the research is to analyse energy aspects of green buildings. The results of research show that the construction of green buildings can significantly result in energy savings and has other benefits for different market participants. Future research directions have been identified as well.

  14. Effect of tip vortices on membrane vibration of flexible wings with different aspect ratios

    NASA Astrophysics Data System (ADS)

    Genç, Mustafa Serdar; Hakan Açikel, Halil; Demir, Hacımurat; Özden, Mustafa; Çağdaş, Mücahit; Isabekov, Iliasbek

    2016-03-01

    In this study, the effect of the aspect ratio on the aerodynamics characteristic of flexible membrane wings with different aspect ratios (AR = 1 and AR = 3) is experimentally investigated at Reynolds number of 25000. Time accurate measurements of membrane deformation using Digital Image Correlation system (DIC) is carried out while normal forces of the wing will be measured by helping a load-cell system and flow on the wing was visualized by means of smoke wire technic. The characteristics of high aspect ratio wings are shown to be affected by leading edge separation bubbles at low Reynolds number. It is concluded that the camber of membrane wing excites the separated shear layer and this situation increases the lift coefficient relatively more as compared to rigid wings. In membrane wings with low aspect ratio, unsteadiness included tip vortices and vortex shedding, and the combination of tip vortices and vortex shedding causes complex unsteady deformations of these membrane wings. The characteristic of high aspect ratio wings was shown to be affected by leading edge separation bubbles at low Reynolds numbers whereas the deformations of flexible wing with low aspect ratio affected by tip vortices and leading edge separation bubbles.

  15. Effect of slot aspect ratio on droplet formation from silicon straight-through microchannels.

    PubMed

    Kobayashi, Isao; Mukataka, Sukekuni; Nakajima, Mitsutoshi

    2004-11-01

    We recently proposed a novel technique for preparing monodisperse emulsions using an array of microfabricated through-holes with an oblong section; we called this array a straight-through microchannel (MC). This paper reports how the slot aspect ratio of the straight-through MC affects droplet formation characteristics. Straight-through MCs with different slot aspect ratios and equivalent diameters of about 20 microm were used. Experimental observation showed that slot aspect ratios exceeding a threshold of approximately 3 were needed to successfully prepare monodisperse emulsions with coefficients of variation below 2%.

  16. Cognitive Psychophysiological Substrates of Affective Temperaments.

    PubMed

    Poyraz, Burç Çağrı; Sakallı Kani, Ayşe; Aksoy Poyraz, Cana; Öcek Baş, Tuba; Arıkan, Mehmet Kemal

    2017-03-01

    Affective temperaments are the subclinical manifestations or phenotypes of mood states and hypothetically represent one healthy end of the mood disorder spectrum. However, there is a scarcity of studies investigating the neurobiological basis of affective temperaments. One fundamental aspect of temperament is the behavioral reactivity to environmental stimuli, which can be effectively evaluated by use of cognitive event-related potentials (ERPs) reflecting the diversity of information processing. The aim of the present study is to explore the associations between P300 and the affective temperamental traits in healthy individuals. We recorded the P300 ERP waves using an auditory oddball paradigm in 50 medical student volunteers (23 females, 27 males). Participants' affective temperaments were evaluated using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-auto questionnaire version (TEMPS-A). In bivariate analyses, depressive temperament score was significantly correlated with P300 latency ( rs = 0.37, P < .01). In a multiple linear regression analysis, P300 latency showed a significant positive correlation with scores of depressive temperament (β = 0.40, P < .01) and a significant negative one with scores of cyclothymic temperament (β = -0.29, P = .03). Affective temperament scores were not associated with P300 amplitude and reaction times. These results indicate that affective temperaments are related to information processing in the brain. Depressive temperament may be characterized by decreased physiological arousal and slower information processing, while the opposite was observed for cyclothymic temperament.

  17. Numerical modelling of river morphodynamics: Latest developments and remaining challenges

    NASA Astrophysics Data System (ADS)

    Siviglia, Annunziato; Crosato, Alessandra

    2016-07-01

    Numerical morphodynamic models provide scientific frameworks for advancing our understanding of river systems. The research on involved topics is an important and socially relevant undertaking regarding our environment. Nowadays numerical models are used for different purposes, from answering questions about basic morphodynamic research to managing complex river engineering problems. Due to increasing computer power and the development of advanced numerical techniques, morphodynamic models are now more and more used to predict the bed patterns evolution to a broad spectrum of spatial and temporal scales. The development and the success of application of such models are based upon a wide range of disciplines from applied mathematics for the numerical solution of the equations to geomorphology for the physical interpretation of the results. In this light we organized this special issue (SI) soliciting multidisciplinary contributions which encompass any aspect needed for the development and applications of such models. Most of the papers in the SI stem from contributions to session HS9.5/GM7.11 on numerical modelling and experiments in river morphodynamics at the European Geosciences Union (EGU) General Assembly held in Vienna, April 27th to May 2nd 2014.

  18. Numerical relativity and spectral methods

    NASA Astrophysics Data System (ADS)

    Grandclement, P.

    2016-12-01

    The term numerical relativity denotes the various techniques that aim at solving Einstein's equations using computers. Those computations can be divided into two families: temporal evolutions on the one hand and stationary or periodic solutions on the other one. After a brief presentation of those two classes of problems, I will introduce a numerical tool designed to solve Einstein's equations: the KADATH library. It is based on the the use of spectral methods that can reach high accuracy with moderate computational resources. I will present some applications about quasicircular orbits of black holes and boson star configurations.

  19. The representation of numerical magnitude

    PubMed Central

    Brannon, Elizabeth M

    2006-01-01

    The combined efforts of many fields are advancing our understanding of how number is represented. Researchers studying numerical reasoning in adult humans, developing humans and non-human animals are using a suite of behavioral and neurobiological methods to uncover similarities and differences in how each population enumerates and compares quantities to identify the neural substrates of numerical cognition. An important picture emerging from this research is that adult humans share with non-human animals a system for representing number as language-independent mental magnitudes and that this system emerges early in development. PMID:16546373

  20. Feeling worse to feel better: pain-offset relief simultaneously stimulates positive affect and reduces negative affect.

    PubMed

    Franklin, Joseph C; Lee, Kent M; Hanna, Eleanor K; Prinstein, Mitchell J

    2013-04-01

    Although pain itself induces negative affect, the removal (or offset) of pain induces a powerful state of relief. Despite being implicated in a wide range of psychological and behavioral phenomena, relief remains a poorly understood emotion. In particular, some theorists associate relief with increased positive affect, whereas others associate relief with diminished negative affect. In the present study, we examined the affective nature of relief in a pain-offset paradigm with psychophysiological measures that were specific to negative valence (startle eyeblink reactivity) and positive valence (startle postauricular reactivity). Results revealed that pain offset simultaneously stimulates positive affect and diminishes negative affect for at least several seconds. Results also indicated that pain intensity differentially affects the positive and negative valence aspects of relief. These findings clarify the affective nature of relief and provide insight into why people engage in both normal and abnormal behaviors associated with relief.

  1. Psychological factors affecting oncology conditions.

    PubMed

    Grassi, Luigi; Biancosino, Bruno; Marmai, Luciana; Rossi, Elena; Sabato, Silvana

    2007-01-01

    The area of psychological factors affecting cancer has been the object of research starting from the early 1950s and consolidating from the 1970s with the development of psychooncology. A series of problems in the DSM and ICD nosological systems, such as the difficult application of the criteria for psychiatric diagnoses (i.e. major depression, adjustment disorders) and the scarce space dedicated to the rubric of psychosocial implications of medical illness (i.e. Psychological Factors Affecting a Medical Condition under 'Other Conditions That May Be a Focus of Clinical Attention' in the DSM-IV) represent a major challenge in psycho-oncology. The application of the Diagnostic Criteria for Psychosomatic Research (DCPR) has been shown to be useful in a more precise identification of several psychological domains in patients with cancer. The DCPR dimensions of health anxiety, demoralization and alexithymia have been shown to be quite frequent in cancer patient (37.7, 28.8 and 26%, respectively). The overlap between a formal DSM-IV diagnosis and the DCPR is low, with 58% of patients being categorized as non-cases on the DSM-IV having at least one DCPR syndrome. The specific quality of the DCPR in characterizing psychosocial aspects secondary to cancer is also confirmed by the fact that some dimensions of coping (e.g. Mini-Mental Adjustment to Cancer subscale hopelessness) correlate with the DCPR dimension of demoralization, while a quantitative approach on symptom assessment (e.g. stress symptoms on the Brief Symptom Inventory) is not useful in discriminating the patients with and without DCPR syndromes. More research is needed in order to understand the relationship between DCPR constructs (e.g. alexithymia) and psychosocial factors which have been shown to be significant in oncology (e.g. emotional repression and avoidance). The role of specific DCPR constructs in influencing the course of illness is also an area that should be investigated.

  2. Affective responses to dance.

    PubMed

    Christensen, Julia F; Pollick, Frank E; Lambrechts, Anna; Gomila, Antoni

    2016-07-01

    The objective of the present work was the characterization of mechanisms by which affective experiences are elicited in observers when watching dance movements. A total of 203 dance stimuli from a normed stimuli library were used in a series of independent experiments. The following measures were obtained: (i) subjective measures of 97 dance-naïve participants' affective responses (Likert scale ratings, interviews); and (ii) objective measures of the physical parameters of the stimuli (motion energy, luminance), and of the movements represented in the stimuli (roundedness, impressiveness). Results showed that (i) participants' ratings of felt and perceived affect differed, (ii) felt and perceived valence but not arousal ratings correlated with physical parameters of the stimuli (motion energy and luminance), (iii) roundedness in posture shape was related to the experience of more positive emotion than edgy shapes (1 of 3 assessed rounded shapes showed a clear effect on positiveness ratings while a second reached trend level significance), (iv) more impressive movements resulted in more positive affective responses, (v) dance triggered affective experiences through the imagery and autobiographical memories it elicited in some people, and (vi) the physical parameters of the video stimuli correlated only weakly and negatively with the aesthetics ratings of beauty, liking and interest. The novelty of the present approach was twofold; (i) the assessment of multiple affect-inducing mechanisms, and (ii) the use of one single normed stimulus set. The results from this approach lend support to both previous and present findings. Results are discussed with regards to current literature in the field of empirical aesthetics and affective neuroscience.

  3. Dosimetric aspects of radiolabeled antibodies for tumor therapy

    SciTech Connect

    Humm, J.L.

    1986-09-01

    Radioimmunotherapy (RIT) is rapidly attracting interest as a potential new weapon in the arsenal for cancer therapy. This article concentrates on some of the dosimetric aspects affecting the potential success of RIT, and examines factors which influence the choice of a radiolabel for RIT. No radionuclide is likely to give an optimum tumor/nontumor insult for all tumor types; therefore, the concept of matching the source to tumor morphology is introduced. Lists of candidate radionuclides are given, classified according to the type of decay, range, and energy of the emission. The article examines how the choice of radionuclide for radiolabeling the antibody affects the local energy deposition in the tumor. Both the effect of tumor size on the energy absorbed fraction and the problem of antibody binding heterogeneity are discussed. The approach to RIT is to relate the choice of radionuclide to the physical properties of the tumor. 26 references.

  4. [Affective disorders: endocrine and metabolic comorbidities].

    PubMed

    Cermolacce, M; Belzeaux, R; Adida, M; Azorin, J-M

    2014-12-01

    Links between affective and endocrine-metabolic disorders are numerous and complex. In this review, we explore most frequent endocrine-metabolic comorbidities. On the one hand, these comorbidities imply numerous iatrogenic effects from antipsychotics (metabolic side-effects) or from lithium (endocrine side-effects). On the other hand, these comorbidities are also associated with affective disorders independently from medication. We will successively examine metabolic syndrome, glycemic disturbances, obesity and thyroid disorders among patients with affective disorders. Endocrinemetabolic comorbidities can be individually encountered, but can also be associated. Therefore, they substantially impact morbidity and mortality by increasing cardiovascular risk factors. Two distinct approaches give an account of processes involved in these comorbidities: common environmental factors (iatrogenic effects, lifestyle), and/or shared physiological vulnerabilities. In conclusion, we provide a synthesis of important results and recommendations related to endocrine-metabolic comorbidities in affective disorders : heavy influence on morbidity and mortality, undertreatment of somatic diseases, importance of endocrine and metabolic side effects from main mood stabilizers, impact from sex and age on the prevalence of comorbidities, influence from previous depressive episodes in bipolar disorders, and relevance of systematic screening for subclinical (biological) disturbances.

  5. Properties of numerical experiments in chaotic dynamical systems

    NASA Astrophysics Data System (ADS)

    Yuan, Guo-Cheng

    1999-10-01

    This dissertation contains four projects that I have worked on during my graduate study at University of Maryland at College Park. These projects are all related to numerical simulations of chaotic dynamical systems. In particular, the two conjectures in Chapter 1 are inspired by the numerical discoveries in Hunt and Ott [1, 2]. In Chapter 2, statistical properties of scalar transport in chaotic flows are investigated by using numerical simulations. In Chapters 3 and 4, I take a different angle and discuss the limitations of numerical simulations; i.e. for certain ``bad'' systems numerical simulations will yield incorrect or at least unreliable results no matter how many digits of precision are used. Chapter 1 discusses the properties of optimal orbits. Given a dynamical system and a function f from the state space to the real numbers, an optimal orbit for f is an orbit over which the average of f is maximal. In this chapter we discuss some basic mathematical aspects of optimal orbits: existence, sensitivity to perturbations of f, and approximability by periodic orbits with low period. For hyperbolic systems, we conjecture that (1)for (topologically) generic smooth functions, there exists an optimal periodic orbit, and (2)the optimal average can be approximated exponentially well by averages over certain periodic orbits with increasing period. In Chapter 2 we theoretically study the power spectrum of passive scalars transported in two dimensional chaotic fluid flows. Using a wave-packet method introduced by Antonsen et al. [3] [4], we numerically investigate several model flows, and confirm that the power spectrum has the k -l- scaling predicted by Batchelor [5]. In Chapter 3 we consider a class of nonhyperbolic systems, for which there are two fixed points in an attractor having a dense trajectory; the unstable manifold of one fixed point has dimension one and the other's is two dimensional. Under the condition that there exists a direction which is more expanding

  6. Circulation patterns in open, wide and deep lacustrine embayments with different aspect ratios

    NASA Astrophysics Data System (ADS)

    Razmi, Amir Mehdi; Barry, David Andrew; Lemmin, Ulrich

    2013-04-01

    Numerical simulations were carried out to examine the effect of different horizontal aspect ratios on wind-induced circulation within open, wide and deep lacustrine embayments. Two adjacent embayments in Lake Geneva, Switzerland, located between Morges and Lausanne on the north shore of the lake, were compared. These embayments were selected because of their similar exposure with respect to wind forcing. However, their aspect ratios are different, making them ideal case studies to evaluate the impact of the aspect ratio on the resulting circulation pattern. A previously validated 3D hydrodynamic model (Delft3D-FLOW) was employed to simulate currents in the lake for the year 2010. Detailed over-lake maps of wind, temperature and humidity were used as input to drive the model. The embayments were compared in terms of circulation patterns and conditions leading to gyre formation. Furthermore, we carried out a systematic comparison, focusing on the embayment aspect ratio by constructing different "synthetic" embayments with aspect ratios in the range 1 - 4. Subsequently, the flow field within these embayments was computed for typical meteorological regimes (dominant wind regimes and seasonality). In particular, the generation of gyres was compared for different cases. The results revealed that, even for large aspect ratios (~ 3), wind-induced circulation can still occur in open, wide, and deep lacustrine embayments. The results showed that, as expected, gyres are formed less frequently as the embayment aspect ratio increases. For this reason, gyres are much more probable in the Morges embayment than in Vidy Bay.

  7. Multiple sclerosis: Experimental and clinical aspects

    SciTech Connect

    Scheinberg, L.; Raine, C.S.

    1984-01-01

    This book discusses the experimental and clinical aspects of multiple sclerosis. Specifically discussed are - Association of Epstein Barr Virus with pathology of central nervous system; immunology of viruses; and immunosuppression.

  8. Some Legal Aspects of Higher Education

    ERIC Educational Resources Information Center

    Kowalski, Casimir J.; And Others

    1977-01-01

    This article explores some legal aspects of public and private education, as well as several Amendments to the Constitution and their relationships to higher education: the First, Fourth, Fifth, Sixth, and Fourteenth Amendments. (Author)

  9. Aspects of prehistoric astronomy in India

    NASA Astrophysics Data System (ADS)

    Rao, N. Kameswara

    2005-12-01

    Some archeoastronomical aspects regarding the development of observational astronomy in India during prehistoric times are described. A plea is made for the preservation of megalithic monuments of possible astronomical significance.

  10. Blepharospasm: Update on Epidemiology, Clinical Aspects, and Pathophysiology

    PubMed Central

    Valls-Sole, Josep; Defazio, Giovanni

    2016-01-01

    Blepharospasm (BSP) is a rather distressing form of focal dystonia. Although many aspects of its pathophysiological mechanisms are already known, we lack fundamental evidence on etiology, prevention, and treatment. To advance in our knowledge, we need to review what is already known in various aspects of the disorder and use these bases to find future lines of interest. Some of the signs observed in BSP are cause, while others are consequence of the disorder. Non-motor symptoms and signs may be a cue for understanding better the disease. Various cerebral sites have been shown to be functionally abnormal in BSP, including the basal ganglia, the cortex, and the cerebellum. However, we still do not know if the dysfunction or structural change affecting these brain regions is cause or consequence of BSP. Further advances in neurophysiology and neuroimaging may eventually clarify the pathophysiological mechanisms implicated. In this manuscript, we aim to update what is known regarding epidemiology, clinical aspects, and pathophysiology of the disorder and speculate on the directions of research worth pursuing in the near future. PMID:27064462

  11. Clarifying the Relation Between Extraversion and Positive Affect.

    PubMed

    Smillie, Luke D; DeYoung, Colin G; Hall, Phillip J

    2015-10-01

    This article clarifies two sources of ambiguity surrounding the relation between extraversion and positive affect. First, positive affect is defined differently across major models of the structure of affect. Second, no previous research has examined potentially diverging associations of lower-order aspects of extraversion (i.e., assertiveness and enthusiasm) with positive affect. Australian (Study 1: N = 437, 78% female, Mage  = 20.41) and American (Study 2: N = 262, 39% female, Mage  = 33.86) participants completed multiple measures of extraversion and positive affect. Correlations were employed to examine relations among these measures. In both studies, extraversion was most clearly associated with positive affect as conceptualized within a major factor model of affect-specifically, as positive activation (Watson & Tellegen, 1985)-rather than the valence-based conceptualization of positive affect provided by a circumplex model of affect (Russell, 1980). This was also the case for the assertiveness and enthusiasm aspects of extraversion. Our findings clarify the nature of the positive affective component of extraversion, which is best described in terms of both positive valence and high activation.

  12. Technical aspects of ileoanal pouch surgery.

    PubMed

    Carne, Peter W G; Pemberton, John H

    2004-02-01

    Ileal pouch-anal anastomosis has become the surgical procedure of choice for chronic ulcerative colitis. Since the initial description of the technique, various modifications have facilitated its evolution into a safe operation with excellent long-term outcomes. However, some aspects of the operation remain contentious. Our aim is to describe the technical aspects of ileal pouch-anal anastomosis and review the current literature in the areas of controversy.

  13. Approaches to high aspect ratio triangulations

    NASA Technical Reports Server (NTRS)

    Posenau, M.-A.

    1993-01-01

    In aerospace computational fluid dynamics calculations, high aspect ratio, or stretched, triangulations are necessary to adequately resolve the features of a viscous flow around bodies. In this paper, we explore alternatives to the Delaunay triangulation which can be used to generate high aspect ratio triangulations of point sets. The method is based on a variation of the lifting map concept which derives Delaunay triangulations from convex hull calculations.

  14. Critiquing the ethical aspects of a study.

    PubMed

    Pat, F

    1995-09-01

    The task of critiquing the ethical aspects of a study is complicated by convention. Research reports are written in a standardised way that may lead to ethical issues being ignored or mentioned only in passing ( 1 ). This can leave room for author and reader to make vastly different assumptions. The reader of a research paper must leant to recognise aspects of the research process which may be in conflict with accepted research ethics.

  15. A numerical investigation of convective sedimentation

    NASA Astrophysics Data System (ADS)

    Snyder, Patrick J.; Hsu, Tian-Jian

    2011-09-01

    Understanding the fate of riverine sediment in the coastal environment is critical to the health of the coastal ecosystem and the changing morphology. One of the least understood mechanisms of initial deposition is the convective sedimentation of hypopycnal plumes. This study aims at investigating convective sedimentation by means of a numerical model for fine sediment transport solving the non-hydrostatic Reynolds-averaged Navier-Stokes equations for stratified turbulent flow. Model validation is sought by comparison to laboratory results for turbidity and saline currents over a changing slope. The model is shown to be capable of predicting both the upstream supercritical and the downstream subcritical flows. The numerical model is then utilized to study convective sedimentation and its depositional and mixing characteristics. By analyzing model results of more than 40 runs for different inlet sediment concentration (density ratio γ), settling velocity (particle Reynolds number Rep), and inlet velocity/height (inlet Reynolds number Re), four distinct flow regimes are revealed. For large γ, we observe divergent plumes with significant deposits near the inlet. For intermediate γ and large Rep, intense convective fingers are predicted which are only marginally affected by ambient shear flow. Further reducing the density ratio γ or Rep gives weak convective fingers that are significantly affected by the ambient shear flow. Eventually, no convective fingers are observed during the computation for very small γ or Rep. Sediment deposits in the divergent plume and intense convective finger regimes are relatively insensitive to Re. Deposit increases with Re in the weak convective finger regime.

  16. [A current and global review of sweeteners. Regulatory aspects].

    PubMed

    García-Almeida, J M; Casado Fdez, Gracia M; García Alemán, J

    2013-07-01

    In this chapter we review the role and potential benefits of non-caloric sweeteners, as part of the diet. After appearing and interest in the beneficial effects attributed to them, face different situations and conditions (obesity, diabetes...), more and more numerous studies, show their ineffective use. In conclusion, further research and results are needed to provide convincing evidence of their long-term effectiveness and the absence of negative effects from their use. The interest of the chapter lies in examining the distinctive aspects of sweeteners compared with sugar, measured as the standard of comparison. We will focus then on the other substances that are commonly used to sweeten foods instead of sugar.

  17. GPU Accelerated Numerical Simulation of Viscous Flow Down a Slope

    NASA Astrophysics Data System (ADS)

    Gygax, Remo; Räss, Ludovic; Omlin, Samuel; Podladchikov, Yuri; Jaboyedoff, Michel

    2014-05-01

    Numerical simulations are an effective tool in natural risk analysis. They are useful to determine the propagation and the runout distance of gravity driven movements such as debris flows or landslides. To evaluate these processes an approach on analogue laboratory experiments and a GPU accelerated numerical simulation of the flow of a viscous liquid down an inclined slope is considered. The physical processes underlying large gravity driven flows share certain aspects with the propagation of debris mass in a rockslide and the spreading of water waves. Several studies have shown that the numerical implementation of the physical processes of viscous flow produce a good fit with the observation of experiments in laboratory in both a quantitative and a qualitative way. When considering a process that is this far explored we can concentrate on its numerical transcription and the application of the code in a GPU accelerated environment to obtain a 3D simulation. The objective of providing a numerical solution in high resolution by NVIDIA-CUDA GPU parallel processing is to increase the speed of the simulation and the accuracy on the prediction. The main goal is to write an easily adaptable and as short as possible code on the widely used platform MATLAB, which will be translated to C-CUDA to achieve higher resolution and processing speed while running on a NVIDIA graphics card cluster. The numerical model, based on the finite difference scheme, is compared to analogue laboratory experiments. This way our numerical model parameters are adjusted to reproduce the effective movements observed by high-speed camera acquisitions during the laboratory experiments.

  18. Conditional Convergence of Numerical Series

    ERIC Educational Resources Information Center

    Gomez, E.; Plaza, A.

    2002-01-01

    One of the most astonishing properties when studying numerical series is that the sum is not commutative, that is the sum may change when the order of its elements is altered. In this note an example is given of such a series. A well-known mathematical proof is given and a MATLAB[C] program used for different rearrangements of the series…

  19. Numerical calculations of flow fields

    NASA Technical Reports Server (NTRS)

    Anderson, D.; Vogel, J. M.

    1973-01-01

    Numerical calculations were made of flow fields generated by various aerodynamic configurations. Data cover flow fields generated by a finitely thick lifting three dimensional wing with subsonic tips moving at supersonic speeds, cross flow instability associated with lifting delta wing configurations such as space shuttles, and flow fields produced by a lifting elliptic cone. Finite difference techniques were used to determine elliptic cone flow.

  20. Numerical Investigation of Thermal and Thermo-mechanical Effective Properties for Short Fibre Reinforced Composite

    NASA Astrophysics Data System (ADS)

    Ioannou, Ioannis; Hodzic, Alma; Gitman, Inna M.

    2016-12-01

    This study aims to investigate the thermal conductivity and the linear coefficient of thermal expansion for short fibre reinforced composites. The study combines numerical and statistical analyses in order to primarily examine the representative size and the effective properties of the volume element. Effects of various micromechanical parameters, such as fibre's aspect ratio and fibre's orientation, on the minimum representative size are discussed. The numerically acquired effective properties, obtained for the representative size, are presented and compared with analytical models.

  1. The Thomas–Fermi quark model: Non-relativistic aspects

    SciTech Connect

    Liu, Quan Wilcox, Walter

    2014-02-15

    The first numerical investigation of non-relativistic aspects of the Thomas–Fermi (TF) statistical multi-quark model is given. We begin with a review of the traditional TF model without an explicit spin interaction and find that the spin splittings are too small in this approach. An explicit spin interaction is then introduced which entails the definition of a generalized spin “flavor”. We investigate baryonic states in this approach which can be described with two inequivalent wave functions; such states can however apply to multiple degenerate flavors. We find that the model requires a spatial separation of quark flavors, even if completely degenerate. Although the TF model is designed to investigate the possibility of many-quark states, we find surprisingly that it may be used to fit the low energy spectrum of almost all ground state octet and decuplet baryons. The charge radii of such states are determined and compared with lattice calculations and other models. The low energy fit obtained allows us to extrapolate to the six-quark doubly strange H-dibaryon state, flavor symmetric strange states of higher quark content and possible six quark nucleon–nucleon resonances. The emphasis here is on the systematics revealed in this approach. We view our model as a versatile and convenient tool for quickly assessing the characteristics of new, possibly bound, particle states of higher quark number content. -- Highlights: • First application of the statistical Thomas–Fermi quark model to baryonic systems. • Novel aspects: spin as generalized flavor; spatial separation of quark flavor phases. • The model is statistical, but the low energy baryonic spectrum is successfully fit. • Numerical applications include the H-dibaryon, strange states and nucleon resonances. • The statistical point of view does not encourage the idea of bound many-quark baryons.

  2. Numerical simulation of solar coronal magnetic fields

    NASA Technical Reports Server (NTRS)

    Dahlburg, Russell B.; Antiochos, Spiro K.; Zang, T. A.

    1990-01-01

    Many aspects of solar activity are believed to be due to the stressing of the coronal magnetic field by footpoint motions at the photosphere. The results are presented of a fully spectral numerical simulation which is the first 3-D time dependent simulation of footpoint stressing in a geometry appropriate for the corona. An arcade is considered that is initially current-free and impose a smooth footpoint motion that produces a twist in the field of approx 2 pi. The footprints were fixed and the evolution was followed until the field relaxes to another current-free state. No evidence was seen for any instability, either ideal or resistive and no evidence for current sheet formation. The most striking feature of the evolution is that in response to photospheric motions, the field expands rapidly upward to minimize the stress. The expansion has two important effects. First, it suppresses the development of dips in the field that could support dense, cool material. For the motions assumed, the magnetic field does not develop a geometry suitable for prominence formation. Second, the expansion inhibits ideal instabilities such as kinking. The results indicate that simple stearing of a single arcade is unlikely to lead to solar activity such as flares or prominences. Effects are discussed that might possibly lead to such activity.

  3. Impact of numerical models on fragmentation processes

    NASA Astrophysics Data System (ADS)

    Renouf, Mathieu; Gezahengn, Belien; Abbas, Micheline; Bourgeois, Florent

    2013-06-01

    Simulated fragmentation process in granular assemblies is a challenging problem which date back the beginning of the 90'. If first approaches have focus on the fragmentation on a single particle, with the development of robust, fast numerical method is is possible today to simulated such process in a large collection of particles. But the question of the fragmentation problem is still open: should the fragmentation be done dynamically (one particle becoming two fragments) and according which criterion or should the fragment paths be defined initially and which is the impact of the discretization and the model of fragments? The present contribution proposes to investigate the second aspect i.e. the impact of fragment modeling on the fragmentation processes. First to perform such an analysis, the geometry of fragments (disks/sphere or polygon/polyhedra), their behavior (rigid/deformable) and the law governing their interactions are investigated. Then such model will be used in a grinding application where the evolution of fragments and impact on the behavior of the whole packing are investigate.

  4. High Rayleigh number convection in rectangular enclosures with differentially heated vertical walls and aspect ratios between zero and unity

    NASA Technical Reports Server (NTRS)

    Kassemi, Siavash A.

    1988-01-01

    High Rayleigh number convection in a rectangular cavity with insulated horizontal surfaces and differentially heated vertical walls was analyzed for an arbitrary aspect ratio smaller than or equal to unity. Unlike previous analytical studies, a systematic method of solution based on linearization technique and analytical iteration procedure was developed to obtain approximate closed-form solutions for a wide range of aspect ratios. The predicted velocity and temperature fields are shown to be in excellent agreement with available experimental and numerical data.

  5. High Rayleigh number convection in rectangular enclosures with differentially heated vertical walls and aspect ratios between zero and unity

    SciTech Connect

    Kassemi, S.A.

    1988-04-01

    High Rayleigh number convection in a rectangular cavity with insulated horizontal surfaces and differentially heated vertical walls was analyzed for an arbitrary aspect ratio smaller than or equal to unity. Unlike previous analytical studies, a systematic method of solution based on linearization technique and analytical iteration procedure was developed to obtain approximate closed-form solutions for a wide range of aspect ratios. The predicted velocity and temperature fields are shown to be in excellent agreement with available experimental and numerical data.

  6. Aspect Ratio Analysis for Ground States of Bosons in Anisotropic Traps

    PubMed Central

    Ilinski, Kirill N.; Moroz, Alexander

    1996-01-01

    Characteristics of the initial condensate in the recent experiment on Bose-Einstein condensation (BEC) of 87Rb atoms in an anisotropic magnetic trap are discussed. Given the aspect ratio R, the quality of BEC is estimated. A simple analytical ansatz for the initial condensate wave function is proposed as a function of the aspect ratio which, in contrast to the Baym-Pethick trial wave function, can be used for any interaction strength, reproduces both the weak and the strong interaction limits, and which is in better agreement with numerical results than the latter. PMID:27805109

  7. On current aspects of finite element computational fluid mechanics for turbulent flows

    NASA Technical Reports Server (NTRS)

    Baker, A. J.

    1982-01-01

    A set of nonlinear partial differential equations suitable for the description of a class of turbulent three-dimensional flow fields in select geometries is identified. On the basis of the concept of enforcing a penalty constraint to ensure accurate accounting of ordering effects, a finite element numerical solution algorithm is established for the equation set and the theoretical aspects of accuracy, convergence and stability are identified and quantized. Hypermatrix constructions are used to formulate the reduction of the computational aspects of the theory to practice. The robustness of the algorithm, and the computer program embodiment, have been verified for pertinent flow configurations.

  8. Individual Differences in Affect.

    ERIC Educational Resources Information Center

    Haviland, Jeannette

    This paper argues that infants' affect patterns are innate and are meaningful indicators of individual differences in internal state. Videotapes of seven infants' faces were coded using an ethogram; the movement of the eyebrow, eye direction, eye openness, mouth shape, mouth position, lip position, and tongue protrusion were assessed…

  9. Affective Factors: Anxiety

    ERIC Educational Resources Information Center

    Tasnimi, Mahshad

    2009-01-01

    Affective factors seem to play a crucial role in success or failure in second language acquisition. Negative attitudes can reduce learners' motivation and harm language learning, while positive attitudes can do the reverse. Discovering students' attitudes about language will help both teacher and student in teaching learning process. Anxiety is…

  10. How Body Affects Brain.

    PubMed

    Suzuki, Wendy A

    2016-08-09

    Studies show that physical exercise can affect a range of brain and cognitive functions. However, little is known about the peripheral signals that initiate these central changes. Moon et al. (2016) provide exciting new evidence that a novel myokine, cathepsin B (CTSB), released with exercise is associated with improved memory.

  11. What Variables Affect Solubility?

    ERIC Educational Resources Information Center

    Baker, William P.; Leyva, Kathryn

    2003-01-01

    Helps middle school students understand the concept of solubility through hands-on experience with a variety of liquids and solids. As they explore factors that affect solubility and saturation, students gain content mastery and an understanding of the inquiry process. Also enables teachers to authentically assess student performance on several…

  12. Food Affects Human Behavior.

    ERIC Educational Resources Information Center

    Kolata, Gina

    1982-01-01

    A conference on whether food and nutrients affect human behavior was held on November 9, 1982 at the Massachusetts Institute of Technology. Various research studies on this topic are reviewed, including the effects of food on brain biochemistry (particularly sleep) and effects of tryptophane as a pain reducer. (JN)

  13. Factors affecting soil cohesion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erodibility is a measure of a soil’s resistance against erosive forces and is affected by both intrinsic (or inherent) soil property and the extrinsic condition at the time erodibility measurement is made. Since soil erodibility is usually calculated from results obtained from erosion experimen...

  14. Further Aspects of Transitions in Two-Dimensional Thermal Convection.

    NASA Astrophysics Data System (ADS)

    Zivkovi, Marina; Agee, Ernest M.

    1988-12-01

    In this paper we present the results of numerical investigation of a two-dimensional nonlinear set of Boussinesq equations governing Bénard-Rayleigh convection using spectral representation in the horizontal direction and finite-difference formulation in the vertical direction. Integrations were characterized by high resolution (up to 171 horizontal modes on 32 levels in the vertical direction) and large domain size (ten linear cells were represented). The results presented were obtained for moderate values of Rayleigh number (1150 < Ra < 33 000) that was varied in a near continuous fashion.It is found that two-dimensional heat flux transitions lead to simulations of various temporal states when sufficient resolution and high aspect-ratio domain of integration are used. The change of slope of the time-averaged logarithmic heat flux curve (log Nu) is simulated in a gradual manner by means of a series of bifurcated solutions.This study demonstrates that transition from steady to time-dependent convection in two-dimensional simulations is the generic property of the Boussinesq equations. The findings highlight the roles of scale truncation and large domain aspect-ratio in simulations of self-organizing properties of thermal convection. They also provide useful information for the application of nonlinear spectral models to the study of organized convection.

  15. Evaluation of environmental aspects significance in ISO 14001.

    PubMed

    Põder, Tõnis

    2006-05-01

    The methodological framework set by standards ISO 14001 and ISO 14004 gives only general principles for environmental aspects assessment, which is regarded as one of the most critical stages of implementing environmental management system. In Estonia, about 100 organizations have been certified to the ISO 14001. Experience obtained from numerous companies has demonstrated that limited transparency and reproducibility of the assessment process serves as a common shortcoming. Despite rather complicated assessment schemes sometimes used, the evaluation procedures have been largely based on subjective judgments because of ill-defined and inadequate assessment criteria. A comparison with some similar studies in other countries indicates a general nature of observed inconsistencies. The diversity of approaches to the aspects' assessment in concept literature and to the related problems has been discussed. The general structure of basic assessment criteria, compatible with environmental impact assessment and environmental risk analysis has also been outlined. Based on this general structure, the article presents a tiered approach to help organize the assessment in a more consistent manner.

  16. Computational Aspects of Data Assimilation and the ESMF

    NASA Technical Reports Server (NTRS)

    daSilva, A.

    2003-01-01

    The scientific challenge of developing advanced data assimilation applications is a daunting task. Independently developed components may have incompatible interfaces or may be written in different computer languages. The high-performance computer (HPC) platforms required by numerically intensive Earth system applications are complex, varied, rapidly evolving and multi-part systems themselves. Since the market for high-end platforms is relatively small, there is little robust middleware available to buffer the modeler from the difficulties of HPC programming. To complicate matters further, the collaborations required to develop large Earth system applications often span initiatives, institutions and agencies, involve geoscience, software engineering, and computer science communities, and cross national borders.The Earth System Modeling Framework (ESMF) project is a concerted response to these challenges. Its goal is to increase software reuse, interoperability, ease of use and performance in Earth system models through the use of a common software framework, developed in an open manner by leaders in the modeling community. The ESMF addresses the technical and to some extent the cultural - aspects of Earth system modeling, laying the groundwork for addressing the more difficult scientific aspects, such as the physical compatibility of components, in the future. In this talk we will discuss the general philosophy and architecture of the ESMF, focussing on those capabilities useful for developing advanced data assimilation applications.

  17. A new clinical tool for assessing numerical abilities in neurological diseases: numerical activities of daily living

    PubMed Central

    Semenza, Carlo; Meneghello, Francesca; Arcara, Giorgio; Burgio, Francesca; Gnoato, Francesca; Facchini, Silvia; Benavides-Varela, Silvia; Clementi, Maurizio; Butterworth, Brian

    2014-01-01

    The aim of this study was to build an instrument, the numerical activities of daily living (NADL), designed to identify the specific impairments in numerical functions that may cause problems in everyday life. These impairments go beyond what can be inferred from the available scales evaluating activities of daily living in general, and are not adequately captured by measures of the general deterioration of cognitive functions as assessed by standard clinical instruments like the MMSE and MoCA. We assessed a control group (n = 148) and a patient group affected by a wide variety of neurological conditions (n = 175), with NADL along with IADL, MMSE, and MoCA. The NADL battery was found to have satisfactory construct validity and reliability, across a wide age range. This enabled us to calculate appropriate criteria for impairment that took into account age and education. It was found that neurological patients tended to overestimate their abilities as compared to the judgment made by their caregivers, assessed with objective tests of numerical abilities. PMID:25126077

  18. Frequency Analysis of Chaotic Flow in Transition to Turbulence in Taylor-Couette System with Small Aspect Ratio

    NASA Astrophysics Data System (ADS)

    Fujii, Tatsuya; Oishi, Yoshihiko; Kawai, Hideki; Kikura, Hiroshige; Stepanus Situmorang, Riky; Ambarita, Himsar

    2017-01-01

    Taylor-Couette flow with small aspect ratio has characteristics such as the different vortex structure, because of a boundary layer of the upper and lower wall and the acceleration of the inner cylinder. In this study, the mechanism of Taylor-Couette system with the small aspect ratio is measured and analyzed by using an ultrasound measurement and a numerical simulation. The process of transition to turbulent flow is observed by using a spectra analysis in a radial and an axial direction. The experimental and numerical results confirmed the characteristics of the broadband component in Taylor-Couette system.

  19. Noise spectroscopy of nanowire structures: fundamental limits and application aspects

    NASA Astrophysics Data System (ADS)

    Vitusevich, Svetlana; Zadorozhnyi, Ihor

    2017-04-01

    Nanowires (NWs) have recently emerged as a new class of materials demonstrating unique properties which may completely differ from their bulk counterparts. The main aim of this work is to give an overview of results on noise and fluctuation phenomena in NW-based structures. We emphasize that noise is one of the main parameters, which determines the characteristics of the device structures and sets the fundamental limits of the working principles and operation regimes of NWs as key electronic elements, including field-effect transistors (FETs). We review the studies focusing on the understanding of noise sources and the main application aspects of noise spectroscopy. Noise application aspects will provide information about the performance of core–shell NW structures, the gate-coupling effect and its advantages for detection of the useful signal with prospects to extract it from the noise level, random telegraph signal as a useful tool for enhanced sensitivity, novel components of noise reflecting dielectric polarization fluctuation processes and fluctuation phenomena as a sensitive tool for molecular charge dynamics in NW FETs. Moreover, noise spectroscopy assists understanding of electronic transport regimes and effects, transport peculiarities in topological materials and aspects reflecting Majorana bound states. Thus noise in NWs on the basis of Si, Ge, Si/Ge, GaAs, InAs, InGaAs, Au, GaAs/AlGaAs, GaAsSb, SnO2, GaN, ZnO, CuO, In2O3 and AlGaN/GaN materials reflects a great variety of phenomena and processes, information about their stability and reliability. It can be utilized for numerous different applications in nanoelectronics and bioelectronics.

  20. Centrifugal pump inlet pressure site affects measurement.

    PubMed

    Augustin, Simon; Horton, Alison; Butt, Warwick; Bennett, Martin; Horton, Stephen

    2010-09-01

    During extracorporeal life support (ECLS), blood is exposed to a myriad of unphysiological factors that can affect outcome. One aspect of this is the sub-atmospheric pressure generated by the ECLS pump and imparted to blood elements along the pump inlet line. This pressure can be measured on the inlet line close to the pump head by adding a connector, or at the venous cannula connection site. We compared the two measurement sites located at both points; between the venous cannula-inlet tubing and inlet tubing-pump, with a range of cannulae and flows. We also investigated the effects on inlet pressure from pump afterload and increasing inlet tubing length.

  1. Dynamic musical communication of core affect.

    PubMed

    Flaig, Nicole K; Large, Edward W

    2014-01-01

    Is there something special about the way music communicates feelings? Theorists since Meyer (1956) have attempted to explain how music could stimulate varied and subtle affective experiences by violating learned expectancies, or by mimicking other forms of social interaction. Our proposal is that music speaks to the brain in its own language; it need not imitate any other form of communication. We review recent theoretical and empirical literature, which suggests that all conscious processes consist of dynamic neural events, produced by spatially dispersed processes in the physical brain. Intentional thought and affective experience arise as dynamical aspects of neural events taking place in multiple brain areas simultaneously. At any given moment, this content comprises a unified "scene" that is integrated into a dynamic core through synchrony of neuronal oscillations. We propose that (1) neurodynamic synchrony with musical stimuli gives rise to musical qualia including tonal and temporal expectancies, and that (2) music-synchronous responses couple into core neurodynamics, enabling music to directly modulate core affect. Expressive music performance, for example, may recruit rhythm-synchronous neural responses to support affective communication. We suggest that the dynamic relationship between musical expression and the experience of affect presents a unique opportunity for the study of emotional experience. This may help elucidate the neural mechanisms underlying arousal and valence, and offer a new approach to exploring the complex dynamics of the how and why of emotional experience.

  2. Dynamic musical communication of core affect

    PubMed Central

    Flaig, Nicole K.; Large, Edward W.

    2013-01-01

    Is there something special about the way music communicates feelings? Theorists since Meyer (1956) have attempted to explain how music could stimulate varied and subtle affective experiences by violating learned expectancies, or by mimicking other forms of social interaction. Our proposal is that music speaks to the brain in its own language; it need not imitate any other form of communication. We review recent theoretical and empirical literature, which suggests that all conscious processes consist of dynamic neural events, produced by spatially dispersed processes in the physical brain. Intentional thought and affective experience arise as dynamical aspects of neural events taking place in multiple brain areas simultaneously. At any given moment, this content comprises a unified “scene” that is integrated into a dynamic core through synchrony of neuronal oscillations. We propose that (1) neurodynamic synchrony with musical stimuli gives rise to musical qualia including tonal and temporal expectancies, and that (2) music-synchronous responses couple into core neurodynamics, enabling music to directly modulate core affect. Expressive music performance, for example, may recruit rhythm-synchronous neural responses to support affective communication. We suggest that the dynamic relationship between musical expression and the experience of affect presents a unique opportunity for the study of emotional experience. This may help elucidate the neural mechanisms underlying arousal and valence, and offer a new approach to exploring the complex dynamics of the how and why of emotional experience. PMID:24672492

  3. Dynamic Synchronization of Teacher-Students Affection in Affective Instruction

    ERIC Educational Resources Information Center

    Zhang, Wenhai; Lu, Jiamei

    2011-01-01

    Based on Bower's affective network theory, the article links the dynamic analysis of affective factors in affective instruction, and presents affective instruction strategic of dynamic synchronization between teacher and students to implement the best ideal mood that promotes students' cognition and affection together. In the process of teaching,…

  4. Computational aspects of pseudospectral Laguerre approximations

    NASA Technical Reports Server (NTRS)

    Funaro, Daniele

    1989-01-01

    Pseudospectral approximations in unbounded domains by Laguerre polynomials lead to ill-conditioned algorithms. Introduced are a scaling function and appropriate numerical procedures in order to limit these unpleasant phenomena.

  5. Definition of sanitary boundaries to prevent ISAv spread between salmon farms in southern Chile based on numerical simulations of currents

    NASA Astrophysics Data System (ADS)

    Olivares, Gonzalo; Sepúlveda, H. H.; Yannicelli, B.

    2015-06-01

    The infectious Salmon Anemia virus (ISAv) is a pathogen that mainly affects the Atlantic Salmon (Salmo salar). It was detected in Norway in 1984 and in June 2007 appeared in Chile, producing a drop of more than 30% in the country's production level. It is expected that with certain regularity, outbreaks will continue to appear in Chile without the need of reintroducing the virus from foreign countries. We present a numerical study of the influence of winds and tides in the dispersion of lagrangian particles to simulate the transport of ISAv in the Aysen region, in southern Chile. This study combines the use of numerical models of the ocean and atmosphere, lagrangian tracking and biological aspects of ISAv infections. As in previous results, a wider dispersion of ISAv was observed during spring tides. Temporal changes in wind significantly modified the transport of viral particles from an infected center. Under similar forcing conditions, the areas of risk associated to culture sites separated by a few kilometers could be very different. Our main results remark the importance of the use of a detailed knowledge of hydrographic and atmospheric circulation in the definition of boundaries for sanitary management areas. We suggest that a methodology similar to the one presented in this study should be considered to define sanitary strategies to minimize the occurrence of native outbreaks of ISAv.

  6. Numerical Modelling of Electrical Discharges

    NASA Astrophysics Data System (ADS)

    Durán-Olivencia, F. J.; Pontiga, F.; Castellanos, A.

    2014-03-01

    The problem of the propagation of an electrical discharge between a spherical electrode and a plane has been solved by means of finite element methods (FEM) using a fluid approximation and assuming weak ionization and local equilibrium with the electric field. The numerical simulation of this type of problems presents the usual difficulties of convection-diffusion-reaction problems, in addition to those associated with the nonlinearities of the charged species velocities, the formation of steep gradients of the electric field and particle densities, and the coexistence of very different temporal scales. The effect of using different temporal discretizations for the numerical integration of the corresponding system of partial differential equations will be here investigated. In particular, the so-called θ-methods will be used, which allows to implement implicit, semi-explicit and fully explicit schemes in a simple way.

  7. Numerical simulation of heat exchanger

    SciTech Connect

    Sha, W.T.

    1985-01-01

    Accurate and detailed knowledge of the fluid flow field and thermal distribution inside a heat exchanger becomes invaluable as a large, efficient, and reliable unit is sought. This information is needed to provide proper evaluation of the thermal and structural performance characteristics of a heat exchanger. It is to be noted that an analytical prediction method, when properly validated, will greatly reduce the need for model testing, facilitate interpolating and extrapolating test data, aid in optimizing heat-exchanger design and performance, and provide scaling capability. Thus tremendous savings of cost and time are realized. With the advent of large digital computers and advances in the development of computational fluid mechanics, it has become possible to predict analytically, through numerical solution, the conservation equations of mass, momentum, and energy for both the shellside and tubeside fluids. The numerical modeling technique will be a valuable, cost-effective design tool for development of advanced heat exchangers.

  8. Numerical Hydrodynamics in Special Relativity.

    PubMed

    Martí, José Maria; Müller, Ewald

    2003-01-01

    This review is concerned with a discussion of numerical methods for the solution of the equations of special relativistic hydrodynamics (SRHD). Particular emphasis is put on a comprehensive review of the application of high-resolution shock-capturing methods in SRHD. Results of a set of demanding test bench simulations obtained with different numerical SRHD methods are compared. Three applications (astrophysical jets, gamma-ray bursts and heavy ion collisions) of relativistic flows are discussed. An evaluation of various SRHD methods is presented, and future developments in SRHD are analyzed involving extension to general relativistic hydrodynamics and relativistic magneto-hydrodynamics. The review further provides FORTRAN programs to compute the exact solution of a 1D relativistic Riemann problem with zero and nonzero tangential velocities, and to simulate 1D relativistic flows in Cartesian Eulerian coordinates using the exact SRHD Riemann solver and PPM reconstruction.

  9. Numerical simulation of gravel packing

    SciTech Connect

    Winterfeld, P.H.; Schroeder, D.E. Jr. )

    1992-08-01

    To obtain maximum productivity from unconsolidated formations where sand control is required, it is important to understand the mechanics of gravel packing. This paper describes a finite-element, numerical simulator that can predict gravel placement in the perforations and annulus of a wellbore. The equations for the simulator include mass and momentum conservation. Wellbore geometry, physical properties, and fluid and gravel-pack properties are simulator input. Experiments in a 100-ft full-scale wellbore model for three gravel-packing configurations have been successfully simulated. These configurations are a circulating pack with a washpipe, a squeeze pack, and a circulating/squeeze pack with a washpipe and a lower telltale screen. The low cost, speed, and extrapolation capabilities of the numerical simulator will greatly enhance our ability to predict gravel placement in a wellbore.

  10. Moore's Law and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Voller, V. R.; Porté-Agel, F.

    2002-07-01

    An estimate of the rate of increase in numerical simulation grid sizes with time is obtained by counting the grids (measured in terms of number of node points) reported in the nine volumes of an established proceedings on the numerical modeling of solidification phenomena dating back to 1980. It is shown that the largest grids used in a given year increase at a rate consistent with the well-known Moore's law on computing power, i.e., the number of nodes in the grids double every 18 months. From this observation, approximate bounds on the available grid size in a current year are established. This approximation is used to provide projections as to when, assuming Moore's law continues to hold, direct simulations of physical phenomena, which resolve to the smallest scale present, will be achievable.

  11. Numerical solutions for patterns statistics on Markov chains.

    PubMed

    Nuel, Gregory

    2006-01-01

    We propose here a review of the methods available to compute pattern statistics on text generated by a Markov source. Theoretical, but also numerical aspects are detailed for a wide range of techniques (exact, Gaussian, large deviations, binomial and compound Poisson). The SPatt package (Statistics for Pattern, free software available at http://stat.genopole.cnrs.fr/spatt) implementing all these methods is then used to compare all these approaches in terms of computational time and reliability in the most complete pattern statistics benchmark available at the present time.

  12. Numerical simulation of a hovering rotor using embedded grids

    NASA Technical Reports Server (NTRS)

    Duque, Earl-Peter N.; Srinivasan, Ganapathi R.

    1992-01-01

    The flow field for a rotor blade in hover was computed by numerically solving the compressible thin-layer Navier-Stokes equations on embedded grids. In this work, three embedded grids were used to discretize the flow field - one for the rotor blade and two to convect the rotor wake. The computations were performed at two hovering test conditions, for a two-bladed rectangular rotor of aspect ratio six. The results compare fairly with experiment and illustrates the use of embedded grids in solving helicopter type flow fields.

  13. Feasibility study for a numerical aerodynamic simulation facility: Summary

    NASA Technical Reports Server (NTRS)

    Lincoln, N. R.

    1979-01-01

    The Ames Research Center of NASA is engaged in the development and investigation of numerical methods and computer technologies to be employed in conjunction with physical experiments, particularly utilizing wind tunnels in the furtherance of the field of aircraft and aerodynamic body design. Several studies, aimed primarily at the areas of development and production of extremely high-speed computing facilities, were conducted. The studies focused on evaluating the aspects of feasibility, reliability, costs, and practicability of designing, constructing, and bringing into effect production of a special-purpose system. An executive summary of the activities for this project is presented in this volume.

  14. Numerical simulation of Ulysses nutation

    NASA Technical Reports Server (NTRS)

    Marirrodriga, C. Garcia; Zeischka, J.; Boslooper, E. C.

    1993-01-01

    A numerical simulation has been performed on the in-orbit instability of the Ulysses Spacecraft. The thermal excitation from the solar flux, the flexible axial boom and its deployment mechanism have been modeled and analyzed. The simulation shows that the nutation build-up has been originated by the solar input on the axial boom coupled with the system nutation frequency of the spacecraft. The results agree with the observed behavior.

  15. Numerical Simulation of Protoplanetary Vortices

    DTIC Science & Technology

    2003-12-01

    UNCLASSIFIED Center for Turbulence Research 81 Annual Research Briefs 2003 Numerical simulation of protoplanetary vortices By H. Lin, J.A. Barranco t AND P.S...planetesimals and planets. In earlier works ( Barranco & Marcus 2000; Barranco et al. 2000; Lin et al. 2000) we have briefly described the possible physical...transport. In particular, Barranco et al. (2000) provided a general mathe- matical framework that is suitable for the asymptotic regime of the disk

  16. Cuba: Multidimensional numerical integration library

    NASA Astrophysics Data System (ADS)

    Hahn, Thomas

    2016-08-01

    The Cuba library offers four independent routines for multidimensional numerical integration: Vegas, Suave, Divonne, and Cuhre. The four algorithms work by very different methods, and can integrate vector integrands and have very similar Fortran, C/C++, and Mathematica interfaces. Their invocation is very similar, making it easy to cross-check by substituting one method by another. For further safeguarding, the output is supplemented by a chi-square probability which quantifies the reliability of the error estimate.

  17. A numerical study of scaling issues for trench power MOSFETs

    NASA Astrophysics Data System (ADS)

    Roig, J.; Cortés, I.; Jiménez, D.; Flores, D.; Iñiguez, B.; Hidalgo, S.; Rebollo, J.

    2005-06-01

    The effect of the scaling down on the electrical performance of trench power MOSFET structures is investigated in this work by means of numerical simulation tools. Layout dimensions of trench power MOSFETs have been continuously reduced in order to decrease the specific on-resistance, maintaining equal vertical dimensions. Nowadays, the last scaling efforts provide trench width and distance between two consecutive trenches in the submicron range. The resultant short distance between gates is expected to induce significant modifications in the device electrical performances, since the fully depletion condition will be feasible in the body region. Hence, the influence of the fully depleted body on the on-state resistance, threshold voltage, breakdown voltage, parasitic bipolar transistor and internal capacitances are features of particular interest. Furthermore, device reliability aspects, such as hot-carrier and self-heating effects, are evaluated by numerical simulation in trench power MOSFETs for the first time.

  18. A Comparison of Metamodeling Techniques via Numerical Experiments

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.

    2016-01-01

    This paper presents a comparative analysis of a few metamodeling techniques using numerical experiments for the single input-single output case. These experiments enable comparing the models' predictions with the phenomenon they are aiming to describe as more data is made available. These techniques include (i) prediction intervals associated with a least squares parameter estimate, (ii) Bayesian credible intervals, (iii) Gaussian process models, and (iv) interval predictor models. Aspects being compared are computational complexity, accuracy (i.e., the degree to which the resulting prediction conforms to the actual Data Generating Mechanism), reliability (i.e., the probability that new observations will fall inside the predicted interval), sensitivity to outliers, extrapolation properties, ease of use, and asymptotic behavior. The numerical experiments describe typical application scenarios that challenge the underlying assumptions supporting most metamodeling techniques.

  19. SToRM: A numerical model for environmental surface flows

    USGS Publications Warehouse

    Simoes, Francisco J.

    2009-01-01

    SToRM (System for Transport and River Modeling) is a numerical model developed to simulate free surface flows in complex environmental domains. It is based on the depth-averaged St. Venant equations, which are discretized using unstructured upwind finite volume methods, and contains both steady and unsteady solution techniques. This article provides a brief description of the numerical approach selected to discretize the governing equations in space and time, including important aspects of solving natural environmental flows, such as the wetting and drying algorithm. The presentation is illustrated with several application examples, covering both laboratory and natural river flow cases, which show the model’s ability to solve complex flow phenomena.

  20. Numerical Relativity Simulations for Black Hole Merger Astrophysics

    NASA Technical Reports Server (NTRS)

    Baker, John G.

    2010-01-01

    Massive black hole mergers are perhaps the most energetic astronomical events, establishing their importance as gravitational wave sources for LISA, and also possibly leading to observable influences on their local environments. Advances in numerical relativity over the last five years have fueled the development of a rich physical understanding of general relativity's predictions for these events. Z will overview the understanding of these event emerging from numerical simulation studies. These simulations elucidate the pre-merger dynamics of the black hole binaries, the consequent gravitational waveform signatures ' and the resulting state, including its kick velocity, for the final black hole produced by the merger. Scenarios are now being considered for observing each of these aspects of the merger, involving both gravitational-wave and electromagnetic astronomy.

  1. Merger of binary neutron stars in numerical relativity

    NASA Astrophysics Data System (ADS)

    Shibata, Masaru

    2014-09-01

    The merger of binary neutron stars is one of most promising sources of gravitational waves. It is also a promising candidate for the central engine of short-hard gamma-ray bursts and a source of the strong transient electromagnetic signal that could be the counterpart of gravitational-wave signals. Numerical relativity is probably the unique tool for theoretically exploring the merger process, and now, it is powerful enough to provide us a wide variety of aspects of the binary-neutron-star merger. In this talk, I will summarize our current understanding of the entire merger event that is obtained by a large-scale numerical-relativity simulations. In particular, I focus on the relation between the neutron-star equation of state and gravitational waves emitted during the late inspiral and merger phase, and observable electromagnetic signal that is likely to be emitted by the dynamical ejecta through r-process nucleosynthesis.

  2. Requirements definition by numerical simulation

    NASA Astrophysics Data System (ADS)

    Hickman, James J.; Kostas, Chris; Tsang, Kang T.

    1994-10-01

    We are investigating the issues involved in requirements definition for narcotics interdiction: how much of a particular signature is possible, how does this amount change for different conditions, and what is the temporal relationship in various scenarios. Our approach has been to simulate numerically the conditions that arise during vapor or particulate transport. The advantages of this approach are that (1) a broad range of scenarios can be rapidly and inexpensively analyzed by simulation, and (2) simulations can display quantities that are difficult or impossible to measure. The drawback of this approach is that simulations cannot include all of the phenomena present in a real measurement, and therefore the fidelity of the simulation results is always an issue. To address this limitation, we will ultimately combine the results of numerical simulations with measurements of physical parameters for inclusion in the simulation. In this paper, we discuss these issues and how they apply to the current problems in narcotics interdictions, especially cargo containers. We also show the results of 1D and 3D numerical simulations, and compare these results with analytical solutions. The results indicate that this approach is viable. We also present data from 3D simulations of vapor transport in a loaded cargo container and some of the issues present in this ongoing work.

  3. In Praise of Numerical Computation

    NASA Astrophysics Data System (ADS)

    Yap, Chee K.

    Theoretical Computer Science has developed an almost exclusively discrete/algebraic persona. We have effectively shut ourselves off from half of the world of computing: a host of problems in Computational Science & Engineering (CS&E) are defined on the continuum, and, for them, the discrete viewpoint is inadequate. The computational techniques in such problems are well-known to numerical analysis and applied mathematics, but are rarely discussed in theoretical algorithms: iteration, subdivision and approximation. By various case studies, I will indicate how our discrete/algebraic view of computing has many shortcomings in CS&E. We want embrace the continuous/analytic view, but in a new synthesis with the discrete/algebraic view. I will suggest a pathway, by way of an exact numerical model of computation, that allows us to incorporate iteration and approximation into our algorithms’ design. Some recent results give a peek into how this view of algorithmic development might look like, and its distinctive form suggests the name “numerical computational geometry” for such activities.

  4. Numerical simulation of conservation laws

    NASA Technical Reports Server (NTRS)

    Chang, Sin-Chung; To, Wai-Ming

    1992-01-01

    A new numerical framework for solving conservation laws is being developed. This new approach differs substantially from the well established methods, i.e., finite difference, finite volume, finite element and spectral methods, in both concept and methodology. The key features of the current scheme include: (1) direct discretization of the integral forms of conservation laws, (2) treating space and time on the same footing, (3) flux conservation in space and time, and (4) unified treatment of the convection and diffusion fluxes. The model equation considered in the initial study is the standard one dimensional unsteady constant-coefficient convection-diffusion equation. In a stability study, it is shown that the principal and spurious amplification factors of the current scheme, respectively, are structurally similar to those of the leapfrog/DuFort-Frankel scheme. As a result, the current scheme has no numerical diffusion in the special case of pure convection and is unconditionally stable in the special case of pure diffusion. Assuming smooth initial data, it will be shown theoretically and numerically that, by using an easily determined optimal time step, the accuracy of the current scheme may reach a level which is several orders of magnitude higher than that of the MacCormack scheme, with virtually identical operation count.

  5. Numerical methods for turbulent flow

    NASA Technical Reports Server (NTRS)

    Turner, James C., Jr.

    1988-01-01

    It has generally become accepted that the Navier-Strokes equations predict the dynamic behavior of turbulent as well as laminar flows of a fluid at a point in space away form a discontinuity such as a shock wave. Turbulence is also closely related to the phenomena of non-uniqueness of solutions of the Navier-Strokes equations. These second order, nonlinear partial differential equations can be solved analytically for only a few simple flows. Turbulent flow fields are much to complex to lend themselves to these few analytical methods. Numerical methods, therefore, offer the only possibility of achieving a solution of turbulent flow equations. In spite of recent advances in computer technology, the direct solution, by discrete methods, of the Navier-Strokes equations for turbulent flow fields is today, and in the foreseeable future, impossible. Thus the only economically feasible way to solve practical turbulent flow problems numerically is to use statistically averaged equations governing mean-flow quantities. The objective is to study some recent developments relating to the use of numerical methods to study turbulent flow.

  6. A Study on Students' Affective Factors in Junior High School English Teaching

    ERIC Educational Resources Information Center

    Zhu, Biyi; Zhou, Yaping

    2012-01-01

    Affect is considered as aspects of emotion, feeling, mood or attitude which condition behaviors in second language acquisition. Positive affect is good for studying while negative affect will inevitably hinder learners' learning process. As we know, students in junior high school are special groups as they are experiencing great changes both in…

  7. Drama and the Representation of Affect--Structures of Feeling and Signs of Learning

    ERIC Educational Resources Information Center

    Franks, Anton

    2014-01-01

    The way in which school students represent affective aspects of human relationships in drama and what this reveals about learning in drama is the focus of this paper. Such an enquiry traverses the borders between affect, intellect, and physicality. Affect and its representation in drama have been themes in the history of drama and theatre and is a…

  8. Cognitive and Affective Dimensions in Health Related Education. Proceedings of a Conference (Gainesville, Florida, January 1974).

    ERIC Educational Resources Information Center

    Morgan, Margaret K., Ed.; And Others

    Ten papers dealing with various aspects of cognitive and affective dimensions of the allied health student are presented. They are: "A Review of Research on Cognitive and Affective Dimensions of Education for the Health Related Professions" by Margaret K. Morgan, "Methodological Problems in the Study of Affective and Cognitive…

  9. Affect in electoral politics.

    PubMed

    Glaser, J; Salovey, P

    1998-01-01

    Recent U.S. history provides vivid illustrations of the importance of politicians' emotional displays in subsequent judgments of them. Yet, a review of empirical research on the role of affect (emotion, mood, and evaluation) in electoral politics reveals little work that has focused on the impact of candidates' emotional expression on voters' preferences for them. A theoretical framework is proposed to identify psychological mechanisms by which a target's displays of emotion influence judgments of that target. Findings from the emerging literature on emotions and politics challenge the traditional assumption of political science that voters make decisions based solely on the cold consideration of nonaffectively charged information. The affect and politics literature, although somewhat unfocused and broad, represents an interdisciplinary domain of study that contributes to the understanding of both electoral politics and social interaction more generally.

  10. Conditions affecting the foreskin.

    PubMed

    Hunter, David

    This article aims to provide an update on the anatomy of, and some of the conditions affecting, the foreskin. The cultural and religious significance of the foreskin will be explored, as well as nursing care and health promotion needs of men. The possible link between circumcision status and human immunodeficiency virus will be briefly discussed. Maintaining cleanliness of the genitals is advocated to reduce the incidence of inflammatory conditions.

  11. Comprehensive affected environment

    SciTech Connect

    1995-10-01

    Energy Vision 2020 evaluates the affected environment to help provide a baseline for measuring the environmental consequences of alternative energy strategies. Because this report is also an environmental impact statement, special emphasis is given to the environment. This regional perspective takes in both natural conditions and those resulting from human development. It considers socioeconomic, air, water, and land resources. This section of the Energy Vision 2020 draft report provides the overview for the environmental assessment.

  12. How differentiated do children experience affect? An investigation of the within- and between-person structure of children's affect.

    PubMed

    Leonhardt, Anja; Könen, Tanja; Dirk, Judith; Schmiedek, Florian

    2016-05-01

    Research on the structure of children's affect is limited. It is possible that children's perception of their own affect might be less differentiated than that of adults. Support for the 2-factor model of positive and negative affect and the pleasure-arousal model suggests that children in middle childhood can distinguish positive and negative affect as well as valence and arousal. Whether children are able to differentiate further aspects of affect, as proposed by the 3-dimensional model of affect (good-bad mood, alertness-tiredness, calmness-tension), is an unresolved issue. The aim of our study was the comparison of these 3 affect models to establish how differentiated children experience their affect and which model best describes affect in children. We examined affect structures on the between- and within-person level, acknowledging that affect varies across time and that no valid interpretation of either level is feasible if both are confounded. For this purpose, 214 children (age 8-11 years) answered affect items once a day for 5 consecutive days on smartphones. We tested all affect models by means of 2-level confirmatory factor analysis. Although all affect models had an acceptable fit, the 3-dimensional model best described affect in children on both the within- and between-person level. Thus, children in middle childhood can already describe affect in a differentiated way. Also, affect structures were similar on the within- and between-person level. We conclude that in order to acquire a thorough picture of children's affect, measures for children should include items of all 3 affect dimensions. (PsycINFO Database Record

  13. A study of radar aspect sensitivity in the lower atmosphere

    NASA Astrophysics Data System (ADS)

    Chen, Charlie Yann-Ting

    2001-09-01

    The goal of this thesis is related to atmospheric temperature measurements using in situ techniques in tandem with a direct numerical simulation to better understand the zenith angle dependence of VHF (30-300 MHz) radar backscatter from the atmosphere. We begin our study with a high-resolution balloon-borne in situ temperature measurement made over Wichita, KS, in 1995. Very steep vertical temperature gradients were found at the edges of vertical potential steps, regions of near zero vertical potential temperature gradient. We use wavelet analysis to isolate the organized components of the signal and, after subtraction from the original signal, the residual signal is found to have the characteristics of isotropic turbulence. This confirms our hypothesis that the measured temperature profile is a superposition of coherent structures and a background isotropic turbulence. From a radar perspective, we show that this wavelet analysis allows us to predict the radar backscatter as a function of zenith angle from a high- resolution one-dimensional temperature measurement. Unfortunately, radar measurements were not available at this point. We next explore the cause of aspect sensitivity directly via a multi-instrument investigation of the lower atmosphere over the Jicamarca Radio Observatory (JRO) near Lima, Peru. The joint analysis of radar backscatter and in situ measurements of the temperature structure shows that a combination of Fresnel scattering and turbulence is the most likely explanation for aspect sensitive echoes. Furthermore, the strong backscatter seems to originate from vertical potential temperature steps; such as those observed over Wichita, KS. Finally, we show that the measured potential temperature steps and the structures seen in a direct numerical simulation (DNS) of a Kelvin-Helmholtz instability (KHI) are remarkably similar. Not only do we find good agreement between the observation and the simulation; the similarity is also seen in the wavelet

  14. Nutritional Aspects of Treatment in Epileptic Patients

    PubMed Central

    SOLTANI, Danesh; GHAFFAR POUR, Majid; TAFAKHORI, Abbas; SARRAF, Payam; BITARAFAN, Sama

    2016-01-01

    Epilepsy is a neurological disorder characterized by interruption of normal neuronal functions that is manifested by behavioral disorders, changing of awareness level, and presence of some sensory, autonomic and motor symptoms or signs. It is resulted from many different causes. Many antiepileptic drugs (AEDs) are considered to manage epileptic attacks. Some of them change metabolism and absorption of many nutrients. Therefore, epileptic patients may be in higher risk of nutrient deficiency and its unwelcome effects. In the present paper, we intend to review the relationship between nutrition and epilepsy in two aspects. In one aspect we discuss the nutritional status in epileptic patients, the causes of nutritional deficiencies and the way of compensation of the nutrient deficiencies. It will guide these patients to have a healthy life. In another aspect we explain the role of some nutrients and specific diets in management of epileptic attacks. It can help to better control of epileptic attacks in these patients. PMID:27375750

  15. Nutritional Aspects of Treatment in Epileptic Patients.

    PubMed

    Soltani, Danesh; Ghaffar Pour, Majid; Tafakhori, Abbas; Sarraf, Payam; Bitarafan, Sama

    2016-01-01

    Epilepsy is a neurological disorder characterized by interruption of normal neuronal functions that is manifested by behavioral disorders, changing of awareness level, and presence of some sensory, autonomic and motor symptoms or signs. It is resulted from many different causes. Many antiepileptic drugs (AEDs) are considered to manage epileptic attacks. Some of them change metabolism and absorption of many nutrients. Therefore, epileptic patients may be in higher risk of nutrient deficiency and its unwelcome effects. In the present paper, we intend to review the relationship between nutrition and epilepsy in two aspects. In one aspect we discuss the nutritional status in epileptic patients, the causes of nutritional deficiencies and the way of compensation of the nutrient deficiencies. It will guide these patients to have a healthy life. In another aspect we explain the role of some nutrients and specific diets in management of epileptic attacks. It can help to better control of epileptic attacks in these patients.

  16. Affect integration in dreams and dreaming.

    PubMed

    Grenell, Gary

    2008-03-01

    The processes by which dreaming aids in the ongoing integration of affects into the mind are approached here from complementary psychoanalytic and nonpsychoanalytic perspectives. One relevant notion is that the dream provides a psychological space wherein overwhelming, contradictory, or highly complex affects that under waking conditions are subject to dissociation, splitting, or disavowal may be brought together for observation by the dreaming ego. This process serves the need for psychological balance and equilibrium. A brief discussion of how the mind processes information during dreaming is followed by a consideration of four component aspects of the integrative process: the nature and use of the dream-space, the oscillating "me / not me" quality of the dream, the apparent reality of the dream, and the use of nonpathological projective identification in dreaming. Three clinical illustrations are offered and discussed.

  17. Numerical and experimental study of strata behavior and land subsidence in an underground coal gasification project

    NASA Astrophysics Data System (ADS)

    Sirdesai, N. N.; Singh, R.; Singh, T. N.; Ranjith, P. G.

    2015-11-01

    Underground Coal Gasification, with enhanced knowledge of hydrogeological, geomechanical and environmental aspects, can be an alternative technique to exploit the existing unmineable reserves of coal. During the gasification process, petro-physical and geomechanical properties undergo a drastic change due to heating to elevated temperatures. These changes, caused due to the thermal anisotropy of various minerals, result in the generation of thermal stresses; thereby developing new fracture pattern. These fractures cause the overhead rock strata to cave and fill the gasification chamber thereby causing subsidence. The degree of subsidence, change in fluid transport and geomechanical properties of the rock strata, in and around the subsidence zone, can affect the groundwater flow. This study aims to predict the thermo-geomechanical response of the strata during UCG. Petro-physical and geomechanical properties are incorporated in the numerical modelling software COMSOL Multiphysics and an analytical strength model is developed to validate and further study the mechanical response and heat conduction of the host rock around the gasification chamber. Once the problems are investigated and solved, the enhanced efficiency and the economic exploitation of gasification process would help meet country's energy demand.

  18. A modified pseudoisochromatic ishihara colour vision test based on eastern arabic numerals.

    PubMed

    Heidary, Fatemeh; Gharebaghi, Reza

    2013-01-01

    Congenital colour vision defects affect about 8% and 0.5% of the male and female population, respectively. Pseudoisochromatic Ishihara plates have shown to be successful in an early diagnosis of colour vision defects. This commonly used colour vision test was initially intended to identify those who suffered from red-green aspect of congenital colour blindness; however, it may be of use to reveal acquired colour vision defects as well. Despite the Ishihara plates' value, there are a number of shortcomings in their current layout. We proposing a new colour plate modified from original Ishihara test. To best assist illiterates who are not able to read English, standard Ishihara plates have been translated to Eastern Arabic numerals, which are used in most parts of the Middle East, Central Asia and Africa populations. The purpose of the present modification was to present the new plates to these regions, but more research and study is required to work on the validity, reliability, and repeatability of these new plates.

  19. A participatory modelling approach to developing a numerical sediment dynamics model

    NASA Astrophysics Data System (ADS)

    Jones, Nicholas; McEwen, Lindsey; Parker, Chris; Staddon, Chad

    2016-04-01

    Fluvial geomorphology is recognised as an important consideration in policy and legislation in the management of river catchments. Despite this recognition, limited knowledge exchange occurs between scientific researchers and river management practitioners. An example of this can be found within the limited uptake of numerical models of sediment dynamics by river management practitioners in the United Kingdom. The uptake of these models amongst the applied community is important as they have the potential to articulate how, at the catchment-scale, the impacts of management strategies of land-use change affect sediment dynamics and resulting channel quality. This paper describes and evaluates a new approach which involves river management stakeholders in an iterative and reflexive participatory modelling process. The aim of this approach was to create an environment for knowledge exchange between the stakeholders and the research team in the process of co-constructing a model. This process adopted a multiple case study approach, involving four groups of river catchment stakeholders in the United Kingdom. These stakeholder groups were involved in several stages of the participatory modelling process including: requirements analysis, model design, model development, and model evaluation. Stakeholders have provided input into a number of aspects of the modelling process, such as: data requirements, user interface, modelled processes, model assumptions, model applications, and model outputs. This paper will reflect on this process, in particular: the innovative methods used, data generated, and lessons learnt.

  20. Numerical approaches to combustion modeling

    SciTech Connect

    Oran, E.S.; Boris, J.P. )

    1991-01-01

    This book presents a series of topics ranging from microscopic combustion physics to several aspects of macroscopic reactive-flow modeling. As the reader progresses into the book, the successive chapters generally include a wider range of physical and chemical processes in the mathematical model. Including more processes, however, usually means that they will be represented phenomenologically at a cruder level. In practice the detailed microscopic models and simulations are often used to develop and calibrate the phenomenologies used in the macroscopic models. The book first describes computations of the most microscopic chemical processes, then considers laminar flames and detonation modeling, and ends with computations of complex, multiphase combustion systems.