Dynamic analysis of the tether transportation system using absolute nodal coordinate formulation
NASA Astrophysics Data System (ADS)
Sun, Xin; Xu, Ming; Zhong, Rui
2017-10-01
Long space tethers are becoming a rising concern as an alternate way for transportation in space. It benefits from fuel economizing. This paper focuses on the dynamics of the tether transportation system, which consists of two end satellites connected by a flexible tether, and a movable vehicle driven by the actuator carried by itself. The Absolute Nodal Coordinate Formulation is applied to the establishment of the equation of motion, so that the influence caused by the distributed mass and elasticity of the tether is introduced. Moreover, an approximated method for accelerating the calculation of the generalized gravitational forces on the tether is proposed by substituting the volume integral every step into summation of finite terms. Afterwards, dynamic evolutions of such a system in different configurations are illustrated using numerical simulations. The deflection of the tether and the trajectory of the crawler during the transportation is investigated. Finally, the effect on the orbit of the system due to the crawler is revealed.
A General-Coordinate Formulation For Boundary-Layer Flow
NASA Technical Reports Server (NTRS)
Steger, Joseph L.; Van Dalsem, William R.; Panaras, Argyris G.; Rao, K. V.
1991-01-01
Formulation for solution of equations of boundary-layer flow in general body-fitted curvilinear coordinates retains velocities in Cartesian coordinates. Increases stability of numerical simulations by avoiding coordinate source terms. In formulation, curvilinear coordinates do not have to be orthogonal, and much of software developed previously for use in numerical simulations of flow based on Navier-Stokes equations used.
Augmented weighted diamond form of the linear nodal scheme for Cartesian coordinate systems
Walters, W.F.
1985-01-01
The equations of the high order linear nodal numerical scheme are cast in an augmented weighted difference form for three-dimensional Cartesian nodes. The coupling exhibited by these equations indicate that this new algorithm is simpler and hence faster than previous nodal schemes of this degree of accuracy. A well-logging problem and a fast reactor problem are examined. The new scheme developed here is compared with the classical linear-linear nodal scheme and the diamond difference scheme. For the well-logging problem, it is found that the new scheme is both faster and simpler than the classical linear-linear nodal scheme while sacrificing little in accuracy. Even though the new scheme is more accurate than the diamond difference scheme for the reactor problem, the results indicate that state of the art acceleration methods are needed for nodal schemes.
Completed Beltrami-Michell Formulation in Polar Coordinates
NASA Technical Reports Server (NTRS)
Patnaik, Surya N.; Hopkins, Dale A.
2005-01-01
A set of conditions had not been formulated on the boundary of an elastic continuum since the time of Saint-Venant. This limitation prevented the formulation of a direct stress calculation method in elasticity for a continuum with a displacement boundary condition. The missed condition, referred to as the boundary compatibility condition, is now formulated in polar coordinates. The augmentation of the new condition completes the Beltrami-Michell formulation in polar coordinates. The completed formulation that includes equilibrium equations and a compatibility condition in the field as well as the traction and boundary compatibility condition is derived from the stationary condition of the variational functional of the integrated force method. The new method is illustrated by solving an example of a mixed boundary value problem for mechanical as well as thermal loads.
Minimal Coordinate Formulation of Contact Dynamics in Operational Space
NASA Technical Reports Server (NTRS)
Jain, Abhinandan; Crean, Cory; Ku, Calvin; Myint, Steven; vonBremen, Hubertus
2012-01-01
In recent years, complementarity techniques have been developed for modeling non-smooth contact and collision dynamics problems for multi-link robotic systems. Normally, in this approach, a linear complementarity problem (LCP) is set up using 6n non-minimal coordinates for a system with n links together with all the unilateral constraints and inter-link bilateral constraints on the system. In this paper, we use operational space dynamics to develop a complementarity formulation for contact and collision dynamics that uses minimal coordinates. The use of such non-redundant coordinates results in much smaller size LCP problems and the automatic enforcement of the inter-link bilateral constraints. Furthermore, we exploit operational space low-order computational algorithms to overcome some of the bottlenecks in using minimal coordinates.
Kinematically redundant arm formulations for coordinated multiple arm implementations
NASA Technical Reports Server (NTRS)
Bailey, Robert W.; Quiocho, Leslie J.; Cleghorn, Timothy F.
1990-01-01
Although control laws for kinematically redundant robotic arms were presented as early as 1969, redundant arms have only recently become recognized as viable solutions to limitations inherent to kinematically sufficient arms. The advantages of run-time control optimization and arm reconfiguration are becoming increasingly attractive as the complexity and criticality of robotic systems continues to progress. A generalized control law for a spatial arm with 7 or more degrees of freedom (DOF) based on Whitney's resolved rate formulation is given. Results from a simulation implementation utilizing this control law are presented. Furthermore, results from a two arm simulation are presented to demonstrate the coordinated control of multiple arms using this formulation.
2015-04-24
Technical Paper 971100. [3] Gruber, P., Sharp, R. S. and Crocombe, A. D., 2012, "Normal and Shear Forces in the Contact Patch of a Braked Racing Tyre ...Part 2: Development of a Physical Tyre Model", Vehicle System Dynamics, vol. 50, pp. 339-356. [4] Sugiyama, H., Yamashita, H. and Jayakumar, P., 2014
2014-03-07
the convergent solution in the case of the continuum mechanics based bi- linear shear deformable ANCF shell element. 5.3 Slit Annular Plate Subjected...UNCLASSIFIED: Distribution Statement A. Approved for public release. #24515 CONTINUUM MECHANICS BASED BI- LINEAR SHEAR DEFORMABLE SHELL ELEMENT...MAR 2014 2. REPORT TYPE Technical Report 3. DATES COVERED 07-01-2014 to 04-03-2014 4. TITLE AND SUBTITLE CONTINUUM MECHANICS BASED BI- LINEAR
Watanabe, Koki; Pištora, Jaromír; Nakatake, Yoshimasa
2012-04-23
This paper considers the electromagnetic scattering problem of periodically corrugated surface with local imperfection of structural periodicity, and presents a formulation based on the coordinate transformation method (C-method). The C-method is originally developed to analyze the plane-wave scattering from perfectly periodic structures, and uses the pseudo-periodic property of the fields. The fields in imperfectly periodic structures are not pseudo-periodic and the C-method cannot be directly applied. This paper introduces the pseudo-periodic Fourier transform to convert the fields in imperfectly periodic structures to pseudo-periodic ones, and the C-method becomes then applicable. © 2012 Optical Society of America
General formulation of vibronic spectroscopy in internal coordinates
NASA Astrophysics Data System (ADS)
Baiardi, Alberto; Bloino, Julien; Barone, Vincenzo
2016-02-01
Our general platform integrating time-independent and time-dependent evaluations of vibronic effects at the harmonic level for different kinds of absorption and emission one-photon, conventional and chiral spectroscopies has been extended to support various sets of internal coordinates. Thanks to the implementation of analytical first and second derivatives of different internal coordinates with respect to cartesian ones, both vertical and adiabatic models are available, with the inclusion of mode mixing and, possibly, Herzberg-Teller contributions. Furthermore, all supported non-redundant sets of coordinates are built from a fully automatized algorithm using only a primitive redundant set derived from a bond order-based molecular topology. Together with conventional stretching, bending, and torsion coordinates, the availability of additional coordinates (including linear and out-of-plane bendings) allows a proper treatment of specific systems, including, for instance, inter-molecular hydrogen bridges. A number of case studies are analysed, showing that cartesian and internal coordinates are nearly equivalent for semi-rigid systems not experiencing significant geometry distortions between initial and final electronic states. At variance, delocalized (possibly weighted) internal coordinates become much more effective than their cartesian counterparts for flexible systems and/or in the presence of significant geometry distortions accompanying electronic transitions.
General formulation of vibronic spectroscopy in internal coordinates.
Baiardi, Alberto; Bloino, Julien; Barone, Vincenzo
2016-02-28
Our general platform integrating time-independent and time-dependent evaluations of vibronic effects at the harmonic level for different kinds of absorption and emission one-photon, conventional and chiral spectroscopies has been extended to support various sets of internal coordinates. Thanks to the implementation of analytical first and second derivatives of different internal coordinates with respect to cartesian ones, both vertical and adiabatic models are available, with the inclusion of mode mixing and, possibly, Herzberg-Teller contributions. Furthermore, all supported non-redundant sets of coordinates are built from a fully automatized algorithm using only a primitive redundant set derived from a bond order-based molecular topology. Together with conventional stretching, bending, and torsion coordinates, the availability of additional coordinates (including linear and out-of-plane bendings) allows a proper treatment of specific systems, including, for instance, inter-molecular hydrogen bridges. A number of case studies are analysed, showing that cartesian and internal coordinates are nearly equivalent for semi-rigid systems not experiencing significant geometry distortions between initial and final electronic states. At variance, delocalized (possibly weighted) internal coordinates become much more effective than their cartesian counterparts for flexible systems and/or in the presence of significant geometry distortions accompanying electronic transitions.
NASA Astrophysics Data System (ADS)
Bazilevs, Y.; Long, C. C.; Akkerman, I.; Benson, D. J.; Shashkov, M. J.
2014-04-01
A recent Isogeometric Analysis (IGA) formulation of Lagrangian shock hydrodynamics [4] is extended to the 3D axisymmetric case. The Euler equations of compressible hydrodynamics are formulated using the rz-cylindrical coordinates, and are discretized in the weak form using NURBS-based IGA. Artificial shock viscosity and internal energy projection are added to stabilize the formulation. The resulting discretization exhibits good accuracy and robustness properties. It also gives exact symmetry preservation on the appropriately constructed meshes. Several benchmark examples are computed to examine the performance of the proposed formulation.
A formulation for the boundary-layer equations in general coordinates
NASA Technical Reports Server (NTRS)
Steger, Joseph L.; Vandalsem, William R.; Panaras, Argyris G.; Rao, K. V.
1988-01-01
This is a working paper in which a formulation is given for solving the boundary-layer equations in general body-fitted curvilinear coordinates while retaining the original Cartesian dependent variables. The solution procedure does not require that any of the coordinates be orthogonal, and much of the software developed for many Navier-Stokes schemes can be readily used. A limited number of calculations has been undertaken to validate the approach.
2012-08-01
an empirically derived constitutive model are two clear assumptions inherent in terramechanics based approaches. The (modified) Bekker soil models...an empirically derived constitutive model are two clear assumptions inherent in terramechanics based approaches. The (modified) Bekker soil models...relationships that could be used to predict at least qualitatively the response of soils under various conditions ( Bekker , 1969). Parametric models, which
Finite element method formulation in polar coordinates for transient heat conduction problems
NASA Astrophysics Data System (ADS)
Duda, Piotr
2016-04-01
The aim of this paper is the formulation of the finite element method in polar coordinates to solve transient heat conduction problems. It is hard to find in the literature a formulation of the finite element method (FEM) in polar or cylindrical coordinates for the solution of heat transfer problems. This document shows how to apply the most often used boundary conditions. The global equation system is solved by the Crank-Nicolson method. The proposed algorithm is verified in three numerical tests. In the first example, the obtained transient temperature distribution is compared with the temperature obtained from the presented analytical solution. In the second numerical example, the variable boundary condition is assumed. In the last numerical example the component with the shape different than cylindrical is used. All examples show that the introduction of the polar coordinate system gives better results than in the Cartesian coordinate system. The finite element method formulation in polar coordinates is valuable since it provides a higher accuracy of the calculations without compacting the mesh in cylindrical or similar to tubular components. The proposed method can be applied for circular elements such as boiler drums, outlet headers, flux tubes. This algorithm can be useful during the solution of inverse problems, which do not allow for high density grid. This method can calculate the temperature distribution in the bodies of different properties in the circumferential and the radial direction. The presented algorithm can be developed for other coordinate systems. The examples demonstrate a good accuracy and stability of the proposed method.
NASA Astrophysics Data System (ADS)
Yan, Zhongbo; Bi, Ren; Shen, Huitao; Lu, Ling; Zhang, Shou-Cheng; Wang, Zhong
2017-07-01
In topological semimetals, the valance band and conduction band meet at zero-dimensional nodal points or one-dimensional nodal rings, which are protected by band topology and symmetries. In this Rapid Communication, we introduce "nodal-link semimetals", which host linked nodal rings in the Brillouin zone. We put forward a general recipe based on the Hopf map for constructing models of nodal-link semimetals. The consequences of nodal ring linking in the Landau levels and Floquet properties are investigated.
Li, Sen; Zhang, Wei; Lian, Jianming; Kalsi, Karanjit
2016-03-01
This paper focuses on the coordination of a population of Thermostatically Controlled Loads (TCLs) with unknown parameters to achieve group objectives. The problem involves designing the bidding and market clearing strategy to motivate self-interested users to realize efficient energy allocation subject to a peak power constraint. Using the mechanism design approach, we propose a market-based coordination framework, which can effectively incorporate heterogeneous load dynamics, systematically deal with user preferences, account for the unknown load model parameters, and enable the real-world implementation with limited communication resources. This paper is divided into two parts. Part I presents a mathematical formulation of the problem and develops a coordination framework using the mechanism design approach. Part II presents a learning scheme to account for the unknown load model parameters, and evaluates the proposed framework through realistic simulations.
NASA Technical Reports Server (NTRS)
Avis, L. M.
1976-01-01
Tensor methods are used to express the continuum equations of motion in general curvilinear, moving, and deforming coordinate systems. The space-time tensor formulation is applicable to situations in which, for example, the boundaries move and deform. Placing a coordinate surface on such a boundary simplifies the boundary condition treatment. The space-time tensor formulation is also applicable to coordinate systems with coordinate surfaces defined as surfaces of constant pressure, density, temperature, or any other scalar continuum field function. The vanishing of the function gradient components along the coordinate surfaces may simplify the set of governing equations. In numerical integration of the equations of motion, the freedom of motion of the coordinate surfaces provides a potential for enhanced resolution of the continuum field function. An example problem of an incompressible, inviscid fluid with a top free surface is considered, where the surfaces of constant pressure (including the top free surface) are coordinate surfaces.
NASA Astrophysics Data System (ADS)
Klawonn, David
2009-05-01
It is shown that nodal sequences determine the underlying manifold up to scaling within classes of rectangles with Dirichlet boundary conditions, separable two-dimensional tori, two-dimensional flat Klein bottles and flat tori in two and three dimensions.
NASA Astrophysics Data System (ADS)
Baumgarte, Thomas W.; Montero, Pedro J.; Cordero-Carrión, Isabel; Müller, Ewald
2013-02-01
In the absence of symmetry assumptions most numerical relativity simulations adopt Cartesian coordinates. While Cartesian coordinates have some desirable properties, spherical polar coordinates appear better suited for certain applications, including gravitational collapse and supernova simulations. Development of numerical relativity codes in spherical polar coordinates has been hampered by the need to handle the coordinate singularities at the origin and on the axis, for example by careful regularization of the appropriate variables. Assuming spherical symmetry and adopting a covariant version of the Baumgarte-Shapiro-Shibata-Nakamura equations, Montero and Cordero-Carrión recently demonstrated that such a regularization is not necessary when a partially implicit Runge-Kutta method is used for the time evolution of the gravitational fields. Here we report on an implementation of the Baumgarte-Shapiro-Shibata-Nakamura equations in spherical polar coordinates without any symmetry assumptions. Using a partially implicit Runge-Kutta method we obtain stable simulations in three spatial dimensions without the need to regularize the origin or the axis. We perform and discuss a number of tests to assess the stability, accuracy and convergence of the code, namely weak gravitational waves, “hydro-without-hydro” evolutions of spherical and rotating relativistic stars in equilibrium, and single black holes.
2009-06-01
targets, whose dynamics are modeled by linear Gauss -Markov processes. They formulated the sensor scheduling problem as one of minimizing the variance...have been developed for overcoming the computational intractability of determining the optimal sensor schedule. For a linear Gauss -Markov system...correspondence,” IEEE Transactions on Aerospace and vol. 1, pp. 296-271, 1959. ahramani and M. I. Jordan , “Factorial hidden Markov models,” Machine
Sarvašová, Zuzana; Sálka, Jaroslav; Dobšinská, Zuzana
2013-09-01
Nature protection as a policy sector is not isolated and is directly or indirectly influenced by many other sectors (e.g. forestry, water management, rural development, energy, etc.). These policy sectors are neither completely segmented nor unaffected by the decisions taken in other policy sectors. Policy formulation in nature protection is therefore also influenced by different sectors. For that reason it is inevitable to stress the need for inter-sectoral coordination to assure their policy coherence. The aim of this article is to describe the mechanism and modes of cross-sectoral coordination and to analyze the relevant actors and their interaction, using the case of the Natura 2000 formulation process in Slovakia. The European Union (EU) set up an ecological network of special protected areas, known as Natura 2000 to ensure biodiversity by conserving natural habitats and wild fauna and flora in the territory of the Member States. An optimized nature protection must therefore carefully consider existing limits and crossdisciplinary relationships at the EU, national and regional levels. The relations between forestry and biodiversity protection are analyzed using the advocacy coalition framework (ACF). The ACF is used for analyzing how two coalitions, in this case ecological and forest owners' coalitions, advocate or pursue their beliefs from the nature protection and forestry policy field. The whole process is illustrated at the regional scale on the case study of Natura 2000 sites formulation in the Slovak Republic. For better reliability and validity of research, a combination of various empiric research methods was used, supported by existing theories. So called triangulation of sociological research or triangulation of methods consists of mutual results testing of individual methodological steps through identifying corresponding political-science theories, assessing their formal points using primary and secondary document analysis and assessing their
NASA Astrophysics Data System (ADS)
Bzdušek, Tomáš; Wu, Quansheng; Rüegg, Andreas; Sigrist, Manfred; Soluyanov, Alexey A.
2016-10-01
The band theory of solids is arguably the most successful theory of condensed-matter physics, providing a description of the electronic energy levels in various materials. Electronic wavefunctions obtained from the band theory enable a topological characterization of metals for which the electronic spectrum may host robust, topologically protected, fermionic quasiparticles. Many of these quasiparticles are analogues of the elementary particles of the Standard Model, but others do not have a counterpart in relativistic high-energy theories. A complete list of possible quasiparticles in solids is lacking, even in the non-interacting case. Here we describe the possible existence of a hitherto unrecognized type of fermionic excitation in metals. This excitation forms a nodal chain—a chain of connected loops in momentum space—along which conduction and valence bands touch. We prove that the nodal chain is topologically distinct from previously reported excitations. We discuss the symmetry requirements for the appearance of this excitation and predict that it is realized in an existing material, iridium tetrafluoride (IrF4), as well as in other compounds of this class of materials. Using IrF4 as an example, we provide a discussion of the topological surface states associated with the nodal chain. We argue that the presence of the nodal-chain fermions will result in anomalous magnetotransport properties, distinct from those of materials exhibiting previously known excitations.
NASA Astrophysics Data System (ADS)
Suh, Kyoung Whoan
2007-02-01
This paper proposes an efficient and comprehensive algorithm for computing the protection ratio and illustrates some results applicable to the initial planning of frequency coordination for fixed wireless networks. A net filter discrimination depending upon transmitter spectrum mask and overall receiver filter characteristic is also examined to see the effect of adjacent channel interferences. Numerical simulations for cochannel and adjacent channel protection ratios are performed for the 6.2 GHz frequency band, including transmitter spectrum mask and receiver filter response. According to results for 64-QAM (quadrature amplitude modulation) and 60 km at bit error ratio 10-6, fade margin and cochannel protection ratio are 41.1 and 74.9 dB, respectively. In addition, it is shown that the net filter discrimination for 30 MHz channel bandwidth provides 26.5 dB at the first adjacent channel, which yields adjacent channel protection ratio of 48.4 dB. The proposed method gives an easy and systematic method to compute the protection ratio and can be applied to frequency coordination in fixed wireless networks up to the millimeter wave band.
Topological nodal line semimetals
NASA Astrophysics Data System (ADS)
Fang, Chen; Weng, Hongming; Dai, Xi; Fang, Zhong
2016-11-01
We review the recent, mainly theoretical, progress in the study of topological nodal line semimetals in three dimensions. In these semimetals, the conduction and the valence bands cross each other along a one-dimensional curve in the three-dimensional Brillouin zone, and any perturbation that preserves a certain symmetry group (generated by either spatial symmetries or time-reversal symmetry) cannot remove this crossing line and open a full direct gap between the two bands. The nodal line(s) is hence topologically protected by the symmetry group, and can be associated with a topological invariant. In this review, (i) we enumerate the symmetry groups that may protect a topological nodal line; (ii) we write down the explicit form of the topological invariant for each of these symmetry groups in terms of the wave functions on the Fermi surface, establishing a topological classification; (iii) for certain classes, we review the proposals for the realization of these semimetals in real materials; (iv) we discuss different scenarios that when the protecting symmetry is broken, how a topological nodal line semimetal becomes Weyl semimetals, Dirac semimetals, and other topological phases; and (v) we discuss the possible physical effects accessible to experimental probes in these materials. Project partially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFA0302400 and 2016YFA0300604), partially by the National Natural Science Foundation of China (Grant Nos. 11274359 and 11422428), the National Basic Research Program of China (Grant No. 2013CB921700), and the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB07020100).
Stream-potential formulation of atmospheric dynamics in pressure-related coordinates
NASA Astrophysics Data System (ADS)
Rõõm, Rein
2014-05-01
Departing from non-hydrostatic covariant equations of motion (1) in isobaric coordinates [1]: δv-= F, v = {dx /dt,dy/dt,dp/dt} = {vx,vy,vp} = {u,v,ω} δt (1) equations of motion for 3D velocity divergence ξ0 and curl ξ are derived 0 δξ- = downtriangle·F, δξ-= downtriangle ×F, ξ0 = downtriangle ·v = δαv α, ξ = downtriangle ×v leftrightarrow ξi = ɛiαβδαvβ δt δt (2) Presenting 3D-velocity v in terms of 4D stream-potential {ψ0,ψx,ψy,ψp} 0 i iα 0 αβγ v = downtriangle ψ + downtriangle × ψ leftrightarrow v = G δα ψ + ɛ δβψγ, where Gij is the metric tensor of pressure (p) or hybrid (η) curved space, subsequent application of div and curl to v yields elliptic equations for {ψ0,ψx,ψy,ψp} ( ) L0ψ0 = ξ0, Liαψα = ξj,L0 = δαG αβδβ, Lij = δα GiαG βj - GiβGαj δβ (3) In native pressure coordinates or for low orography, when G becomes diagonal with main elements 11 22 33 2 2 G = G = 1, G = p /H , (H = RT /g istheheightscale) system (3) can be reduced to three independent equations (4) for three fields - scalar flow potential ψ0, horizontal divergence Ξ = δxψx + δyψy of stream function and vertical pessure-velocity ω = δxψy - δyψx ≠¡ dp/dt: ( ) p2 p2 δ2 p2 δ2 L0ψ0 = ξ0, L0Ξ = δp p2ξp/H2 ,Lω = H2- (δyξx - δxξy)L0 = H2-δp2+ downtriangle2, L = H2-δp2+downtriangle2. (4) As the velocity v is specified by the triplet ω,Ξ,ψ0, in full, Eqs. (2) and (4) represent alternate to (1) equations of motion and constitute along with the scale-height (temperature) and surface pressure equations dH R H ω RQ δps δ« ps -dt = c-p- + -g-, δt- = downtriangle · vdp p 0 (5) a complete set for non-hydrostatic modelling of atmospheric dynamics. Equations for ξ0,ψ0,ps represent the 'acoustic loop', which withdraws to the external wave equation for surface pressure fluctuation at slow quasi-hydrostatic motion limit (QHL: ψ0 → 0). Equations for ξ,Ξ,ω,H constitute a non-linear, third
Nodalization study for BETHSY experiment
Petelin, S.; Mavko, B.; Ravnikar, I.; Cebull, P.; Hassan, Y.A.
1996-08-01
The BETHSY experiment 9.1.b was used to assess different versions of the RELAP5 computer code using three various detailed nodalizations. This experimental transient scenario involved a scaled 2 inch cold leg break without high pressure safety injection and with delayed operator action for a secondary system depressurization. In order to optimize details of nodalization regard to satisfactory accuracy a detailed study of different RELAP5 codes and nodalizations was performed. Qualitative evolution of RELAP5 code was also analyzed.
NASA Astrophysics Data System (ADS)
Ishizuka, Ryosuke; Yoshida, Norio
2013-08-01
An extended molecular Ornstein-Zernike (XMOZ) integral equation is formulated to calculate the spatial distribution of solvent around a solute of arbitrary shape and solid surfaces. The conventional MOZ theory employs spherical harmonic expansion technique to treat the molecular orientation of components of solution. Although the MOZ formalism is fully exact analytically, the truncation of the spherical harmonic expansion requires at a finite order for numerical calculation and causes the significant error for complex molecules. The XMOZ integral equation is the natural extension of the conventional MOZ theory to a rectangular coordinate system, which is free from the truncation of spherical harmonic expansion with respect to solute orientation. In order to show its applicability, we applied the XMOZ theory to several systems using the hypernetted-chain (HNC) and Kovalenko-Hirata approximations. The quality of results obtained within our theory is discussed by comparison with values from the conventional MOZ theory, molecular dynamics simulation, and three-dimensional reference interaction site model theory. The spatial distributions of water around the complex of non-charged sphere and dumbbell were calculated. Using this system, the approximation level of the XMOZ and other methods are discussed. To assess our theory, we also computed the excess chemical potentials for three realistic molecules (water, methane, and alanine dipeptide). We obtained the qualitatively reasonable results by using the XMOZ/HNC theory. The XMOZ theory covers a wide variety of applications in solution chemistry as a useful tool to calculate solvation thermodynamics.
Universal nodal Fermi velocity
Zhou, X.J.; Yoshida, T.; Lanzara, A.; Bogdanov, P.V.; Kellar, S.A.; Shen, K.M.; Yang, W.L.; Ronning, F.; Sasagawa, T.; Kakeshita, T.; Noda, T.; Eisaki, H.; Uchida, S.; Lin, C.T.; Zhou, F.; Xiong, J.W.; Ti, W.X.; Zhao, Z.X.; Fujimori, A.; Hussain, Z.; Shen, Z.-X.
2003-05-27
The physical properties of cuprate superconductors vary dramatically as a function of doping, evolving from antiferromagnetic insulator to superconductors, and to normal metal upon doping. They also vary among different families of compounds, most prominent being the superconducting transition temperature (Tc), which ranges from 38 K for optimally-doped (La2-xSrx)CuO4 (x=0.15) to 135 K for Hg2Ba2Ca2Cu3O10. Such dramatic changes with doping and material family have been observed in transport properties, optical response, magnetic excitation spectra, the superconducting condensation energy and superfluid density. All these seem to imply that the underlying microscopic quantities of cup rates are generally non-universal. This paper presents a striking exception by providing experimental evidence that the nodal Fermi velocity, a quantity that governs the low-energy quasiparticle dynamics along the (0,0)-(p,p) direction where the d-wave superconducting gap is zero in cuprate superconductors , is actually universal. This conclusion is based on extensive measurements from a wide range of doping, and from five families of hole-doped cuprates whose maximum Tc varies by a factor of three or more. The invariance of the nodal Fermi velocity all the way to the Mott insulator boundary clearly signals the breakdown of the conventional Fermi liquid theory where the metal-insulator transition is realized by the divergence of the effective mass near the insulator boundary. A possible way to understand this behavior is the nanoscale phase separation where doped holes tend to create a preferred local environment so that the behavior of the individual hole is more or less the same for low energy dynamics
Long period nodal motion of sun synchronous orbits
NASA Technical Reports Server (NTRS)
Duck, K. I.
1975-01-01
An approximative model is formulated for assessing these perturbations that significantly affect long term modal motion of sun synchronous orbits. Computer simulations with several independent computer programs consider zonal and tesseral gravitational harmonics, third body gravitational disturbances induced by the sun and the moon, and atmospheric drag. A pendulum model consisting of evenzonal harmonics through order 4 and solar gravity dominated nodal motion approximation. This pendulum motion results from solar gravity inducing an inclination oscillation which couples into the nodal precession induced by the earth's oblateness. The pendulum model correlated well with simulations observed flight data.
Nodal line optimization and its application to violin top plate design
NASA Astrophysics Data System (ADS)
Yu, Yonggyun; Jang, In Gwun; Kim, In Kyum; Kwak, Byung Man
2010-10-01
In the literature, most problems of structural vibration have been formulated to adjust a specific natural frequency: for example, to maximize the first natural frequency. In musical instruments like a violin; however, mode shapes are equally important because they are related to sound quality in the way that natural frequencies are related to the octave. The shapes of nodal lines, which represent the natural mode shapes, are generally known to have a unique feature for good violins. Among the few studies on mode shape optimization, one typical study addresses the optimization of nodal point location for reducing vibration in a one-dimensional beam structure. However, nodal line optimization, which is required in violin plate design, has not yet been considered. In this paper, the central idea of controlling the shape of the nodal lines is proposed and then applied to violin top plate design. Finite element model for a violin top plate was constructed using shell elements. Then, optimization was performed to minimize the square sum of the displacement of selected nodes located along the target nodal lines by varying the thicknesses of the top plate. We conducted nodal line optimization for the second and the fifth modes together at the same time, and the results showed that the nodal lines obtained match well with the target nodal lines. The information on plate thickness distribution from nodal line optimization would be valuable for tailored trimming of a violin top plate for the given performances.
A composite nodal finite element for hexagons
Hennart, J.P.; Mund, E.H. |; Valle, E. Del
1997-10-01
A nodal algorithm for the solution of the multigroup diffusion equations in hexagonal arrays is analyzed. Basically, the method consists of dividing each hexagon into four quarters and mapping the hexagon quarters onto squares. The resulting boundary value problem on a quadrangular domain is solved in primal weak formulation. Nodal finite element methods like the Raviart-Thomas RTk schemes provide accurate analytical expansions of the solution in the hexagons. Transverse integration cannot be performed on the equations in the quadrangular domain as simply as it is usually done on squares because these equations have essentially variable coefficients. However, by considering an auxiliary problem with constant coefficients (on the same quadrangular domain) and by using a preconditioning approach, transverse integration can be performed as for rectangular geometry. A description of the algorithm is given for a one-group diffusion equation. Numerical results are presented for a simple model problem with a known analytical solution and for k{sub eff} evaluations of some benchmark problems proposed in the literature. For the analytical problem, the results indicate that the theoretical convergence orders of RTk schemes (k = 0,1) are obtained, yielding accurate solutions at the expense of a few preconditioning iterations.
Super-nodal methods for space-time kinetics
NASA Astrophysics Data System (ADS)
Mertyurek, Ugur
The purpose of this research has been to develop an advanced Super-Nodal method to reduce the run time of 3-D core neutronics models, such as in the NESTLE reactor core simulator and FORMOSA nuclear fuel management optimization codes. Computational performance of the neutronics model is increased by reducing the number of spatial nodes used in the core modeling. However, as the number of spatial nodes decreases, the error in the solution increases. The Super-Nodal method reduces the error associated with the use of coarse nodes in the analyses by providing a new set of cross sections and ADFs (Assembly Discontinuity Factors) for the new nodalization. These so called homogenization parameters are obtained by employing consistent collapsing technique. During this research a new type of singularity, namely "fundamental mode singularity", is addressed in the ANM (Analytical Nodal Method) solution. The "Coordinate Shifting" approach is developed as a method to address this singularity. Also, the "Buckling Shifting" approach is developed as an alternative and more accurate method to address the zero buckling singularity, which is a more common and well known singularity problem in the ANM solution. In the course of addressing the treatment of these singularities, an effort was made to provide better and more robust results from the Super-Nodal method by developing several new methods for determining the transverse leakage and collapsed diffusion coefficient, which generally are the two main approximations in the ANM methodology. Unfortunately, the proposed new transverse leakage and diffusion coefficient approximations failed to provide a consistent improvement to the current methodology. However, improvement in the Super-Nodal solution is achieved by updating the homogenization parameters at several time points during a transient. The update is achieved by employing a refinement technique similar to pin-power reconstruction. A simple error analysis based on the relative
PoroTomo: Map of DAS, Nodal, Vibroseis and Reftek Station Deployment
Kurt Feigl
2016-10-15
Map of DAS, nodal, vibroseis and Reftek stations during March 2016 deployment. The plot on the left has nodal stations labeled; the plot on the right has vibroseis observations labeled. Stations are shown in map-view using Brady's rotated X-Y coordinates with side plots denoting elevation with respect to the WGS84 ellipsoid. Blue circles denote vibroseis data, x symbols denote DAS (cyan for horizontal and magenta for vertical), black asterisks denote Reftek data, and red plus signs denote nodal data. This map can be found on UW-Madison's askja server at /PoroTomo/DATA/MAPS/Deployment_Stations.pdf
Polymorphic nodal elements and their application in discontinuous Galerkin methods
NASA Astrophysics Data System (ADS)
Gassner, Gregor J.; Lörcher, Frieder; Munz, Claus-Dieter; Hesthaven, Jan S.
2009-03-01
In this work, we discuss two different but related aspects of the development of efficient discontinuous Galerkin methods on hybrid element grids for the computational modeling of gas dynamics in complex geometries or with adapted grids. In the first part, a recursive construction of different nodal sets for hp finite elements is presented. They share the property that the nodes along the sides of the two-dimensional elements and along the edges of the three-dimensional elements are the Legendre-Gauss-Lobatto points. The different nodal elements are evaluated by computing the Lebesgue constants of the corresponding Vandermonde matrix. In the second part, these nodal elements are applied within the modal discontinuous Galerkin framework. We still use a modal based formulation, but introduce a nodal based integration technique to reduce computational cost in the spirit of pseudospectral methods. We illustrate the performance of the scheme on several large scale applications and discuss its use in a recently developed space-time expansion discontinuous Galerkin scheme.
Preserving spherical symmetry in axisymmetric coordinates for diffusion problems
Brunner, T. A.; Kolev, T. V.; Bailey, T. S.; Till, A. T.
2013-07-01
Persevering symmetric solutions, even in the under-converged limit, is important to the robustness of production simulation codes. We explore the symmetry preservation in both a continuous nodal and a mixed finite element method. In their standard formulation, neither method preserves spherical solution symmetry in axisymmetric (RZ) coordinates. We propose two methods, one for each family of finite elements, that recover spherical symmetry for low-order finite elements on linear or curvilinear meshes. This is a first step toward understanding achieving symmetry for higher-order elements. (authors)
Antiferromagnetic topological nodal line semimetals
NASA Astrophysics Data System (ADS)
Wang, Jing
2017-08-01
We study three-dimensional nodal line semimetals (NLSMs) with magnetic ordering and strong spin-orbit interaction. Two distinct classes of magnetic NLSMs are proposed. The first class is band-inversion NLSM where the accidental line node is induced by band inversion and locally protected by glide mirror plane and the combined time-reversal and inversion symmetries. This can be viewed as a trivial stacking of the two-dimensional antiferromagnetic Dirac semimetals. The second class is essential NLSM where the nodal features are filling enforced by specific magnetic symmetry group. We further provide two concrete tight-binding models for magnetic NLSMs which belong to these two different classes, respectively. We conclude with a brief discussion on the possible material venues and the experimental implications for such phases.
NASA Astrophysics Data System (ADS)
Kopp, Wassja A.; Leonhard, Kai
2016-12-01
We show how inverse metric tensors and rovibrational kinetic energy operators in terms of internal bond-angle coordinates can be obtained analytically following a factorization of the Jacobian worked out by Frederick and Woywod. The structure of these Jacobians is exploited in two ways: On one hand, the elements of the metric tensor as well as its determinant all have the form ∑rmsin (αn) cos (βo) . This form can be preserved by working with the adjugate metric tensor that can be obtained without divisions. On the other hand, the adjugate can be obtained with less effort by exploiting the lower triangular structure of the Jacobians. Together with a suitable choice of the wavefunction, we avoid singularities and show how to obtain analytical expressions for the rovibrational kinetic energy matrix elements.
Orbital nodal surfaces: Topological challenges for density functionals
NASA Astrophysics Data System (ADS)
Aschebrock, Thilo; Armiento, Rickard; Kümmel, Stephan
2017-06-01
Nodal surfaces of orbitals, in particular of the highest occupied one, play a special role in Kohn-Sham density-functional theory. The exact Kohn-Sham exchange potential, for example, shows a protruding ridge along such nodal surfaces, leading to the counterintuitive feature of a potential that goes to different asymptotic limits in different directions. We show here that nodal surfaces can heavily affect the potential of semilocal density-functional approximations. For the functional derivatives of the Armiento-Kümmel (AK13) [Phys. Rev. Lett. 111, 036402 (2013), 10.1103/PhysRevLett.111.036402] and Becke88 [Phys. Rev. A 38, 3098 (1988), 10.1103/PhysRevA.38.3098] energy functionals, i.e., the corresponding semilocal exchange potentials, as well as the Becke-Johnson [J. Chem. Phys. 124, 221101 (2006), 10.1063/1.2213970] and van Leeuwen-Baerends (LB94) [Phys. Rev. A 49, 2421 (1994), 10.1103/PhysRevA.49.2421] model potentials, we explicitly demonstrate exponential divergences in the vicinity of nodal surfaces. We further point out that many other semilocal potentials have similar features. Such divergences pose a challenge for the convergence of numerical solutions of the Kohn-Sham equations. We prove that for exchange functionals of the generalized gradient approximation (GGA) form, enforcing correct asymptotic behavior of the potential or energy density necessarily leads to irregular behavior on or near orbital nodal surfaces. We formulate constraints on the GGA exchange enhancement factor for avoiding such divergences.
Hejranfar, Kazem; Saadat, Mohammad Hossein; Taheri, Sina
2017-02-01
In this work, a high-order weighted essentially nonoscillatory (WENO) finite-difference lattice Boltzmann method (WENOLBM) is developed and assessed for an accurate simulation of incompressible flows. To handle curved geometries with nonuniform grids, the incompressible form of the discrete Boltzmann equation with the Bhatnagar-Gross-Krook (BGK) approximation is transformed into the generalized curvilinear coordinates and the spatial derivatives of the resulting lattice Boltzmann equation in the computational plane are solved using the fifth-order WENO scheme. The first-order implicit-explicit Runge-Kutta scheme and also the fourth-order Runge-Kutta explicit time integrating scheme are adopted for the discretization of the temporal term. To examine the accuracy and performance of the present solution procedure based on the WENOLBM developed, different benchmark test cases are simulated as follows: unsteady Taylor-Green vortex, unsteady doubly periodic shear layer flow, steady flow in a two-dimensional (2D) cavity, steady cylindrical Couette flow, steady flow over a 2D circular cylinder, and steady and unsteady flows over a NACA0012 hydrofoil at different flow conditions. Results of the present solution are compared with the existing numerical and experimental results which show good agreement. To show the efficiency and accuracy of the solution methodology, the results are also compared with the developed second-order central-difference finite-volume lattice Boltzmann method and the compact finite-difference lattice Boltzmann method. It is shown that the present numerical scheme is robust, efficient, and accurate for solving steady and unsteady incompressible flows even at high Reynolds number flows.
NASA Astrophysics Data System (ADS)
Hejranfar, Kazem; Saadat, Mohammad Hossein; Taheri, Sina
2017-02-01
In this work, a high-order weighted essentially nonoscillatory (WENO) finite-difference lattice Boltzmann method (WENOLBM) is developed and assessed for an accurate simulation of incompressible flows. To handle curved geometries with nonuniform grids, the incompressible form of the discrete Boltzmann equation with the Bhatnagar-Gross-Krook (BGK) approximation is transformed into the generalized curvilinear coordinates and the spatial derivatives of the resulting lattice Boltzmann equation in the computational plane are solved using the fifth-order WENO scheme. The first-order implicit-explicit Runge-Kutta scheme and also the fourth-order Runge-Kutta explicit time integrating scheme are adopted for the discretization of the temporal term. To examine the accuracy and performance of the present solution procedure based on the WENOLBM developed, different benchmark test cases are simulated as follows: unsteady Taylor-Green vortex, unsteady doubly periodic shear layer flow, steady flow in a two-dimensional (2D) cavity, steady cylindrical Couette flow, steady flow over a 2D circular cylinder, and steady and unsteady flows over a NACA0012 hydrofoil at different flow conditions. Results of the present solution are compared with the existing numerical and experimental results which show good agreement. To show the efficiency and accuracy of the solution methodology, the results are also compared with the developed second-order central-difference finite-volume lattice Boltzmann method and the compact finite-difference lattice Boltzmann method. It is shown that the present numerical scheme is robust, efficient, and accurate for solving steady and unsteady incompressible flows even at high Reynolds number flows.
ANOVA-HDMR structure of the higher order nodal diffusion solution
Bokov, P. M.; Prinsloo, R. H.; Tomasevic, D. I.
2013-07-01
Nodal diffusion methods still represent a standard in global reactor calculations, but employ some ad-hoc approximations (such as the quadratic leakage approximation) which limit their accuracy in cases where reference quality solutions are sought. In this work we solve the nodal diffusion equations utilizing the so-called higher-order nodal methods to generate reference quality solutions and to decompose the obtained solutions via a technique known as High Dimensional Model Representation (HDMR). This representation and associated decomposition of the solution provides a new formulation of the transverse leakage term. The HDMR structure is investigated via the technique of Analysis of Variance (ANOVA), which indicates why the existing class of transversely-integrated nodal methods prove to be so successful. Furthermore, the analysis leads to a potential solution method for generating reference quality solutions at a much reduced calculational cost, by applying the ANOVA technique to the full higher order solution. (authors)
Left–Right Determination: Involvement of Molecular Motor KIF3, Cilia, and Nodal Flow
Hirokawa, Nobutaka; Tanaka, Yosuke; Okada, Yasushi
2009-01-01
Mammalian left–right determination is a good example for how multiple cell biological processes coordinate in the formation of a basic body plan. The leftward movement of fluid at the ventral node, called nodal flow, is the central process in symmetry breaking on the left–right axis. Nodal flow is autonomously generated by the rotation of posteriorly tilted cilia that are built by transport via KIF3 motor on cells of the ventral node. How nodal flow is interpreted to create left–right asymmetry has been a matter of debate. Recent evidence suggests that the leftward movement of sheathed lipidic particles, called nodal vesicular parcels (NVPs), may result in the activation of the noncanonical hedgehog signaling pathway, an asymmetric elevation in intracellular Ca2+ and changes in gene expression. PMID:20066075
Heterogeneous treatment in the variational nodal method
Fanning, T.H.; Palmiotti, G.
1995-06-01
The variational nodal transport method is reduced to its diffusion form and generalized for the treatment of heterogeneous nodes while maintaining nodal balances. Adapting variational methods to heterogeneous nodes requires the ability to integrate over a node with discontinuous cross sections. In this work, integrals are evaluated using composite gaussian quadrature rules, which permit accurate integration while minimizing computing time. Allowing structure within a nodal solution scheme avoids some of the necessity of cross section homogenization, and more accurately defines the intra-nodal flux shape. Ideally, any desired heterogeneity can be constructed within the node; but in reality, the finite set of basis functions limits the practical resolution to which fine detail can be defined within the node. Preliminary comparison tests show that the heterogeneous variational nodal method provides satisfactory results even if some improvements are needed for very difficult, configurations.
A difference-equation formalism for the nodal domains of separable billiards
Manjunath, Naren; Samajdar, Rhine; Jain, Sudhir R.
2016-09-15
Recently, the nodal domain counts of planar, integrable billiards with Dirichlet boundary conditions were shown to satisfy certain difference equations in Samajdar and Jain (2014). The exact solutions of these equations give the number of domains explicitly. For complete generality, we demonstrate this novel formulation for three additional separable systems and thus extend the statement to all integrable billiards.
Optical conductivity of nodal metals
Homes, C. C.; Tu, J. J.; Li, J.; Gu, G. D.; Akrap, A.
2013-01-01
Fermi liquid theory is remarkably successful in describing the transport and optical properties of metals; at frequencies higher than the scattering rate, the optical conductivity adopts the well-known power law behavior σ1(ω) ∝ ω−2. We have observed an unusual non-Fermi liquid response σ1(ω) ∝ ω−1±0.2 in the ground states of several cuprate and iron-based materials which undergo electronic or magnetic phase transitions resulting in dramatically reduced or nodal Fermi surfaces. The identification of an inverse (or fractional) power-law behavior in the residual optical conductivity now permits the removal of this contribution, revealing the direct transitions across the gap and allowing the nature of the electron-boson coupling to be probed. The non-Fermi liquid behavior in these systems may be the result of a common Fermi surface topology of Dirac cone-like features in the electronic dispersion. PMID:24336241
Tiwari, Madhu; Kumar, Ashish; Shankar, Uma; Prakash, Rajiv
2016-11-15
The present report highlights a cost effective and portable AMT-Ag nanocrystalline coordination polymer (NCCP) based electrochemical sensor for an efficient sensing of biologically active drug molecule ciprofloxacin hydrochloride (CFX). The AMT-Ag NCCP, is synthesized using an easily accessible organic ligand 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) with silver nitrate. In the infinite polymer array of AMT-Ag, silver (I) centers are bridged by tecton AMT through the exocyclic thiol and amino linkage. A successful ultra‒trace detection of CFX has been achieved due to the prominent electron channeling through the pores of polymeric nano-crystallites. The efficient charge transfer arises at the interface of electrolyte and AMT-Ag nano-crystals anchored electrode through hydrophobic interaction and π-π electron coupling. The voltammogram reveals the critical redox features of CFX and provides a clear representation about the steps involved in the AMT-Ag assisted oxidation of CFX. This specific signature further applied in the voltammetric assay of CFX in pharmaceutical formulation (eye drops) and biological fluid (urine) by a significantly high sensitivity (0.002µA/µM and 0.007µA/µM) and detection limit (22nM and 60nM) respectively without any interference. Therefore, the developed AMT-Ag NCCP could serve as a highly valuable platform for the fabrication of high-performance electrochemical sensors for the detection of biologically important drug molecules. Copyright © 2016 Elsevier B.V. All rights reserved.
Distributions of Nodal Prices in PJM Market
NASA Astrophysics Data System (ADS)
Kunio, Matsumoto; Yoshio, Ichida; Michiko, Makino; Hiroaki, Tanaka
As the deregulation of electric business proceeds, it is important to analyze the distributions of prices in the power market. In this paper, we analyze the nodal prices of the PJM market, which is representative of power markets in the US. First, we verify Weibull’s property of the distribution of nodal prices. Then we verify Poisson’s property of the interval of loss process.
Nodal network generator for CAVE3
NASA Technical Reports Server (NTRS)
Palmieri, J. V.; Rathjen, K. A.
1982-01-01
A new extension of CAVE3 code was developed that automates the creation of a finite difference math model in digital form ready for input to the CAVE3 code. The new software, Nodal Network Generator, is broken into two segments. One segment generates the model geometry using a Tektronix Tablet Digitizer and the other generates the actual finite difference model and allows for graphic verification using Tektronix 4014 Graphic Scope. Use of the Nodal Network Generator is described.
Nodal signalling determines biradial asymmetry in Hydra.
Watanabe, Hiroshi; Schmidt, Heiko A; Kuhn, Anne; Höger, Stefanie K; Kocagöz, Yigit; Laumann-Lipp, Nico; Ozbek, Suat; Holstein, Thomas W
2014-11-06
In bilaterians, three orthogonal body axes define the animal form, with distinct anterior-posterior, dorsal-ventral and left-right asymmetries. The key signalling factors are Wnt family proteins for the anterior-posterior axis, Bmp family proteins for the dorsal-ventral axis and Nodal for the left-right axis. Cnidarians, the sister group to bilaterians, are characterized by one oral-aboral body axis, which exhibits a distinct biradiality of unknown molecular nature. Here we analysed the biradial growth pattern in the radially symmetrical cnidarian polyp Hydra, and we report evidence of Nodal in a pre-bilaterian clade. We identified a Nodal-related gene (Ndr) in Hydra magnipapillata, and this gene is essential for setting up an axial asymmetry along the main body axis. This asymmetry defines a lateral signalling centre, inducing a new body axis of a budding polyp orthogonal to the mother polyp's axis. Ndr is expressed exclusively in the lateral bud anlage and induces Pitx, which encodes an evolutionarily conserved transcription factor that functions downstream of Nodal. Reminiscent of its function in vertebrates, Nodal acts downstream of β-Catenin signalling. Our data support an evolutionary scenario in which a 'core-signalling cassette' consisting of β-Catenin, Nodal and Pitx pre-dated the cnidarian-bilaterian split. We presume that this cassette was co-opted for various modes of axial patterning: for example, for lateral branching in cnidarians and left-right patterning in bilaterians.
Preserved nodal number effects under equal reinforcement.
Wang, Ting; Dack, Charlotte; McHugh, Louise; Whelan, Robert
2011-09-01
The present set of experiments tested the hypothesis that the nodal number effects observed in previous studies of stimulus equivalence were due to the confounding factor of training structure that resulted in unequal reinforcement across trial types. In Experiment 1, two 5-member equivalence classes were trained across equal and unequal reinforcement conditions, both with and without a limited hold. A significant nodal effect, as measured by response speed, was found in the equal reinforcement, no-limited-hold condition. In Experiment 2, two 6-member equivalence classes were trained in equal and unequal reinforcement conditions without limited hold. In a transfer-of-function test, clear nodal effects were observed in the equal reinforcement condition. Experiment 3 replicated and extended the findings of Experiments 1 and 2 with an increased number of baseline training trials. The results of the present study suggest that the effects of nodal number are independent of differential reinforcement. Furthermore, a transfer-of-function test was most sensitive to nodal effects, response speed was the next most sensitive measure, and response accuracy was the least sensitive measure of nodal effects.
Nodal Quasiparticle in Pseudogapped Colossal Magnetoresistive Manganites
Mannella, N.
2010-06-02
A characteristic feature of the copper oxide high-temperature superconductors is the dichotomy between the electronic excitations along the nodal (diagonal) and antinodal (parallel to the Cu-O bonds) directions in momentum space, generally assumed to be linked to the d-wave symmetry of the superconducting state. Angle-resolved photoemission measurements in the superconducting state have revealed a quasiparticle spectrum with a d-wave gap structure that exhibits a maximum along the antinodal direction and vanishes along the nodal direction. Subsequent measurements have shown that, at low doping levels, this gap structure persists even in the high-temperature metallic state, although the nodal points of the superconducting state spread out in finite Fermi arcs. This is the so-called pseudogap phase, and it has been assumed that it is closely linked to the superconducting state, either by assigning it to fluctuating superconductivity or by invoking orders which are natural competitors of d-wave superconductors. Here we report experimental evidence that a very similar pseudogap state with a nodal-antinodal dichotomous character exists in a system that is markedly different from a superconductor: the ferromagnetic metallic groundstate of the colossal magnetoresistive bilayer manganite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}. Our findings therefore cast doubt on the assumption that the pseudogap state in the copper oxides and the nodal-antinodal dichotomy are hallmarks of the superconductivity state.
Primary extra nodal Hodgkin disease: Bone presentation.
Nikolica, Goran; Badnjar, Zorka; Cadjenovic, Tanja; Raceta-Masic, Dijana
2014-01-01
Extra nodal and extra lymphatic propagation of Hodgkin's disease is a characteristic of the fourth stage of disease when the organs are affected. Primary appearances of the disease outside the lymph node is a rare event. Therefore, it makes diagnostic problem. Skeletal system is possible localization of primary extra nodal Hodgkin's disease. Women, 42-years-old, was admitted to hospital because of swelling and pain in the right shoulder. After imaging and histological examination diagnosed Hodgkin's nodular sclerosing histological subtype disease has been established. The patient starts to receive chemotherapy. Primary extra nodal Hodgkin's disease of bone is manifested with painful swelling in geared area. Imaging method shows destruction of the affected bone, with swelling of the soft tissues. Propagation in soft tissue is not accompanied by their destruction, but rather manifested swelling of the surrounding soft tissue.
MURR nodal analysis with simple interactive simulation
NASA Astrophysics Data System (ADS)
Enani, Mohammad Abdulsamad
The main goal of this research is to design and produce computer codes that should do a NODAL analysis of the core of Missouri University Research Reactor 'MURR' with a simple neutron transient simulation. These codes should be executed on any of the family of the widely used modern IBM/PC (or IBM/PS) microcomputers (or compatibles). The nodal analysis code should find the power (or flux) distribution inside the reactor core and calculate fuel burnup for each of the fuel elements by using the nodal analysis technique described in chapter 3. The simulator code is a relatively simple, educational aid of MURR reactor kinetics simulation that uses one group point reactor model.
Fuerer, Christophe; Nostro, M. Cristina; Constam, Daniel B.
2014-01-01
The TGFβ family member Nodal is central to control pluripotent stem cell fate, but its use as a stem cell differentiation factor is limited by low specific activity. During development, Nodal depends on growth and differentiation factor (Gdf)-1 and on the shared co-receptor Cryptic to specify visceral left-right axis asymmetry. We therefore asked whether the functionality of Nodal can be augmented by Gdf1. Because Nodal and Gdf1 coimmunoprecipitate each other, they were predicted to form heterodimers, possibly to facilitate diffusion or to increase the affinity for signaling receptors. Here, we report that Gdf1 suppresses an unexpected dependence of Nodal on serum proteins and that it is critically required for non-autonomous signaling in cells expressing Cryptic. Nodal, Gdf1, and their cleaved propeptides copurified as a heterodimeric low molecular weight complex that stimulated Activin receptor (Acvr) signaling far more potently than Nodal alone. Although heterodimerization with Gdf1 did not increase binding of Nodal to Fc fusions of co-receptors or Acvr extracellular domains, it was essential for soluble Acvr2 to inhibit Nodal signaling. This implies that Gdf1 potentiates Nodal activity by stabilizing a low molecular weight fraction that is susceptible to neutralization by soluble Acvr2. Finally, in differentiating human ES cells, endodermal markers were more efficiently induced by Nodal·Gdf1 than by Nodal, suggesting that Nodal·Gdf1 is an attractive new reagent to direct stem cell differentiation. PMID:24798330
Percutaneous Radiofrequency Ablation of Nodal Metastases
Gervais, Debra A.; Arellano, Ronald S.; Mueller, Peter R.
2002-12-15
We report our experience with percutaneous image-guided radiofrequency (RF) ablation to treat isolated nodal metastases. Four patients underwent image-guided percutaneous RF ablation of metastatic disease involving retrocrural nodes,retroperitoneal nodes, or pelvic nodes. Coagulation necrosis was achieved in all cases.
Drift Hamiltonian in magnetic coordinates
White, R.B.; Boozer, A.H.; Hay, R.
1982-02-01
A Hamiltonian formulation of the guiding-center drift in arbitrary, steady state, magnetic and electric fields is given. The canonical variables of this formulation are simply related to the magnetic coordinates. The modifications required to treat ergodic magnetic fields using magnetic coordinates are explicitly given in the Hamiltonian formulation.
Pathology of extra-nodal non Hodgkin lymphomas.
Wright, D H
2012-06-01
In the management of extra-nodal lymphomas it is important to determine whether the tumour has disseminated and whether lymph nodes are involved. Some extra-nodal lymphomas may be the result of random spread of nodal lymphoma. Specific homing, however, determines the site of many extra-nodal lymphomas, as exemplified by cutaneous T-cell lymphomas, which seem to be derived from skin-homing T-cells and mucosa-associated lymphoid tissue lymphomas that show features of the mucosal immune system. Enteropathy-associated T-cell lymphoma is derived from mucosal T-cells in patients with coeliac disease. Immunological sanctuary accounts for the localisation of primary brain, eye and testicular lymphoma. Mantle cell lymphoma frequently causes tumours in the gastrointestinal tract. Random biopsies have shown that a high proportion of patients with this lymphoma have extensive occult involvement of the gastrointestinal tract at the time of first diagnosis. Follicular lymphoma occurs at both nodal and extra-nodal sites, but uncommonly at both sites at the same time. Extra-nodal follicular lymphomas frequently lack t(14;18)(q32;q21) and do not express bcl-2, which are characteristics of the nodal disease. At extra-nodal sites, follicular lymphoma is more likely to be curable than nodal follicular lymphoma. The behaviour of extra-nodal lymphomas cannot be assumed to follow that of their nodal counterparts.
State-Space Formulation for Circuit Analysis
ERIC Educational Resources Information Center
Martinez-Marin, T.
2010-01-01
This paper presents a new state-space approach for temporal analysis of electrical circuits. The method systematically obtains the state-space formulation of nondegenerate linear networks without using concepts of topology. It employs nodal/mesh systematic analysis to reduce the number of undesired variables. This approach helps students to…
State-Space Formulation for Circuit Analysis
ERIC Educational Resources Information Center
Martinez-Marin, T.
2010-01-01
This paper presents a new state-space approach for temporal analysis of electrical circuits. The method systematically obtains the state-space formulation of nondegenerate linear networks without using concepts of topology. It employs nodal/mesh systematic analysis to reduce the number of undesired variables. This approach helps students to…
NOKIN1D: one-dimensional neutron kinetics based on a nodal collocation method
NASA Astrophysics Data System (ADS)
Verdú, G.; Ginestar, D.; Miró, R.; Jambrina, A.; Barrachina, T.; Soler, Amparo; Concejal, Alberto
2014-06-01
The TRAC-BF1 one-dimensional kinetic model is a formulation of the neutron diffusion equation in the two energy groups' approximation, based on the analytical nodal method (ANM). The advantage compared with a zero-dimensional kinetic model is that the axial power profile may vary with time due to thermal-hydraulic parameter changes and/or actions of the control systems but at has the disadvantages that in unusual situations it fails to converge. The nodal collocation method developed for the neutron diffusion equation and applied to the kinetics resolution of TRAC-BF1 thermal-hydraulics, is an adaptation of the traditional collocation methods for the discretization of partial differential equations, based on the development of the solution as a linear combination of analytical functions. It has chosen to use a nodal collocation method based on a development of Legendre polynomials of neutron fluxes in each cell. The qualification is carried out by the analysis of the turbine trip transient from the NEA benchmark in Peach Bottom NPP using both the original 1D kinetics implemented in TRAC-BF1 and the 1D nodal collocation method.
Nodal resonance in a strong standing wave
NASA Astrophysics Data System (ADS)
Fernández C., David J.; Mielnik, Bogdan
1990-06-01
The motion of charged particles in a standing electromagnetic wave is considered. For amplitudes that are not too high, the wave causes an effect of attraction of particles to the nodal points, resembling the channeling effect reported by Salomon, Dalibard, Aspect, Metcalf, and Cohen-Tannoudji [Phys. Rev. Lett. 59, 1659 (1987)] consistent with the ``high-frequency potential'' of Kapitza [Zh. Eksp. Teor. Fiz. 21, 588 (1951)]. For high-field intensities, however, the nodal points undergo a qualitative metamorphosis, converting themselves from particle attractors into resonant centers. Some chaotic phenomena arise and the description of the oscillating field in terms of an ``effective potential'' becomes inappropriate. The question of a correct Floquet Hamiltonian that could describe the standing wave within this amplitude and frequency regime is open.
NASA Technical Reports Server (NTRS)
Borsody, J.
1976-01-01
Mathematical equations are derived by using the Maximum Principle to obtain the maximum payload capability of a reusable tug for planetary missions. The mathematical formulation includes correction for nodal precession of the space shuttle orbit. The tug performs this nodal correction in returning to this precessed orbit. The sample case analyzed represents an inner planet mission as defined by the declination (fixed) and right ascension of the outgoing asymptote and the mission energy. Payload capability is derived for a typical cryogenic tug and the sample case with and without perigee propulsion. Optimal trajectory profiles and some important orbital elements are also discussed.
Filho, J. F. P.
2013-07-01
In this work, an analytical discrete ordinates method is used to solve a nodal formulation of a neutron transport problem in x, y-geometry. The proposed approach leads to an important reduction in the order of the associated eigenvalue systems, when combined with the classical level symmetric quadrature scheme. Auxiliary equations are proposed, as usually required for nodal methods, to express the unknown fluxes at the boundary introduced as additional unknowns in the integrated equations. Numerical results, for the problem defined by a two-dimensional region with a spatially constant and isotropically emitting source, are presented and compared with those available in the literature. (authors)
Multiple nodal locoregional recurrence of pheochromocytoma
Ramírez-Plaza, César Pablo; Cárdenas, Elena Margarita Sanchiz; Humanes, Rocío Soler
2015-01-01
Introduction Malignancy is present in 10% of pheochromocytomas (PCC) and is defined as local/vascular infiltration of surrounding tissues or the presence of chromaffin cells deposits in distant organs. The presence of isolated nodal recurrence is very rare and only 7 cases have been reported in the medical literature. Presentation of the case The case of a 32-y male with a symptomatic recurrence of a previously operated (2-years ago) PCC is presented. Radiological and functional imaging studies confirmed the presence of multiple nodules in the surgical site. A radical left nephrectomy with extensive lymphatic clearance in order to get an R0 resection was performed. The pathologist confirmed the diagnosis of massive locoregional nodal invasion. Discussion A detailed histological report and a thorough genetic study must be considered in every operated PCC in order to identify mutations and profiles of risk for malignancy. When recurrence or metastastic disease is suspected, imaging and functional exams are done in order to obtain a proper staging. Radical surgery for the metastatic disease is the only treatment that may provide prolonged survival. If an R0 resection is not possible, then a debulking surgery is a good option when the benefit/risk ratio is acceptable. Conclusion Isolated lymph nodal recurrence is very rare in malignant PCC, with only 7 cases previously published. The role of surgery is essential to get long-term survival because provides clinical and functional control of the disease. PMID:26117450
Arbitrarily high order nodal and characteristic methods
Azmy, Y.Y.
1994-09-01
The quest for higher computational efficiency initially led researchers in the neutron transport area to develop and implement high-order approximations for solving the linear Boltzmann equational. This drive aimed at achieving higher accuracy on coarse meshes, thereby resulting in a net savings of computational resources represented by execution time and memory. Many endeavors succeeded in reaching this goal, producing a variety of elegent, albeit complicated, formalisms, that proved extremely accurate and efficient in solving test, as well as practical applications, problems. The two main classes of high order transport methods that recieved the most attention are the Nodal and Characteristic methods. A de facto linear order standard for the spatial approximation (even though Quadratic Nodal Methods were also considered) was dictated by the algebraic complexity of the derivation of the discrete variable equations, the programming complexity of implementing and verifying them in codes, and limitations on computational resources available to run such codes. The significant advances in computational resources in terms of hardware capacity and speed, as well as architectural innovations such as vector and parallel processing, all but eliminated the third (above) obstacle towards the development and implementation of even higher order methods. The algebraic and programming complexities, on the other hand, were alleviated to some extent by the development of Arbitrarily High Order Transport methods of the Nodal and the Characteristic types, which are discussed in this report.
NASA Astrophysics Data System (ADS)
Zhang, Xiaoming; Yu, Zhi-Ming; Sheng, Xian-Lei; Yang, Hui Ying; Yang, Shengyuan A.
2017-06-01
Topological metals with protected band-crossing points have been attracting great interest. Here we report topological band features in a family of metal diboride materials. Using first-principles calculations, we show that these materials are metallic, and close to Fermi level, there appears coexistence of one pair of nodal rings and one pair of triply degenerate nodal points (TNPs). The nodal ring here is distinct from the previously studied ones in that its formation requires four entangled bands, not just two as in previous cases, hence it is termed as a four-band nodal ring (FNR). Remarkably, we show that FNR features Dirac-cone-like surface states, in contrast to the usual drumhead surface states for two-band nodal rings. Due to the presence of inversion symmetry, the TNP here is also different from those discussed previously in inversion-asymmetric systems. Especially, when spin-orbit coupling is included, the TNP here transforms into a novel Dirac point that is close to the borderline between the type-I and type-II Dirac point categories. We discuss their respective symmetry protections, and construct effective models for their characterization. The large linear energy range (>2 eV) in these materials should facilitate the experimental detection of the signatures of these nontrivial band crossings.
A nodal triangle-based spectral element method for the shallow water equations on the sphere
NASA Astrophysics Data System (ADS)
Giraldo, F. X.; Warburton, T.
2005-07-01
A nodal triangle-based spectral element (SE) method for the shallow water equations on the sphere is presented. The original SE method uses quadrilateral elements and high-order nodal Lagrange polynomials, constructed from a tensor-product of the Legendre-Gauss-Lobatto points. In this work, we construct the high-order Lagrange polynomials directly on the triangle using nodal sets obtained from the electrostatics principle [J.S. Hesthaven, From electrostatics to almost optimal nodal sets for polynomial interpolation in a simplex, SIAM Journal on Numerical Analysis 35 (1998) 655-676] and Fekete points [M.A. Taylor, B.A. Wingate, R.E. Vincent, An algorithm for computing Fekete points in the triangle, SIAM Journal on Numerical Analysis 38 (2000) 1707-1720]. These points have good approximation properties and far better Lebesgue constants than any other nodal set derived for the triangle. By employing triangular elements as the basic building-blocks of the SE method and the Cartesian coordinate form of the equations, we can use any grid imaginable including adaptive unstructured grids. Results for six test cases are presented to confirm the accuracy and stability of the method. The results show that the triangle-based SE method yields the expected exponential convergence and that it can be more accurate than the quadrilateral-based SE method even while using 30-60% fewer grid points especially when adaptive grids are used to align the grid with the flow direction. However, at the moment, the quadrilateral-based SE method is twice as fast as the triangle-based SE method because the latter does not yield a diagonal mass matrix.
Plasticity underlies tumor progression: Role of Nodal signaling
Bodenstine, Thomas M.; Chandler, Grace S.; Seftor, Richard E. B.; Seftor, Elisabeth A.; Hendrix, Mary J. C.
2016-01-01
The transforming growth factor beta (TGFβ) superfamily member Nodal is an established regulator of early embryonic development, with primary roles in endoderm induction, left-right asymmetry and primitive streak formation. Nodal signals through TGFβ family receptors at the plasma membrane and induces signaling cascades leading to diverse transcriptional regulation. While conceptually simple, the regulation of Nodal and its molecular effects are profoundly complex and context dependent. Pioneering work by developmental biologists has characterized the signaling pathways, regulatory components, and provided detailed insight into the mechanisms by which Nodal mediates changes at the cellular and organismal levels. Nodal is also an important factor in maintaining pluripotency of embryonic stem cells through regulation of core transcriptional programs. Collectively, this work has led to an appreciation for Nodal as a powerful morphogen capable of orchestrating multiple cellular phenotypes. Although Nodal is not active in most adult tissues, its re-expression and signaling have been linked to multiple types of human cancer, and Nodal has emerged as a driver of tumor growth and cellular plasticity. In vitro and in vivo experimental evidence has demonstrated that inhibition of Nodal signaling reduces cancer cell aggressive characteristics, while clinical data have established associations with Nodal expression and patient outcomes. As a result, there is great interest in the potential targeting of Nodal activity in a therapeutic setting for cancer patients that may provide new avenues for suppressing tumor growth and metastasis. In this review, we evaluate our current understanding of the complexities of Nodal function in cancer and highlight recent experimental evidence that sheds light on the therapeutic potential of its inhibition. PMID:26951550
Small renal tumor with lymph nodal enlargement: A histopathological surprise
Thottathil, Mujeeburahiman; Verma, Ashish; D’souza, Nischith; Khan, Altaf
2016-01-01
Renal cancer with lymph nodal mass on the investigation is clinically suggestive of an advanced tumor. Small renal cancers are not commonly associated with lymph nodal metastasis. Association of renal cell carcinoma with renal tuberculosis (TB) in the same kidney is also rare. We report here a case of small renal cancer with multiple hilar and paraaortic lymph nodes who underwent radical nephrectomy, and histopathology report showed renal and lymph nodal TB too. PMID:27453671
The AN neutron transport by nodal diffusion
Barbarino, A.; Tomatis, D.
2013-07-01
The two group diffusion model combined to a nodal approach in space is the preferred scheme for the industrial simulation of nuclear water reactors. The main selling point is the speed of computation, allowing a large number of parametric studies. Anyway, the drawbacks of the underlying diffusion equation may arise with highly heterogeneous interfaces, often encountered in modern UO{sub 2} and MO{sub x} fuel loading patterns, and boron less controlled systems. This paper aims at showing how the simplified AN transport model, equivalent to the well known SPN, can be implemented in standard diffusion codes with minor modifications. Some numerical results are illustrated. (authors)
Topological surface states in nodal superconductors.
Schnyder, Andreas P; Brydon, Philip M R
2015-06-24
Topological superconductors have become a subject of intense research due to their potential use for technical applications in device fabrication and quantum information. Besides fully gapped superconductors, unconventional superconductors with point or line nodes in their order parameter can also exhibit nontrivial topological characteristics. This article reviews recent progress in the theoretical understanding of nodal topological superconductors, with a focus on Weyl and noncentrosymmetric superconductors and their protected surface states. Using selected examples, we review the bulk topological properties of these systems, study different types of topological surface states, and examine their unusual properties. Furthermore, we survey some candidate materials for topological superconductivity and discuss different experimental signatures of topological surface states.
Quantitative analytical theory for disordered nodal points
NASA Astrophysics Data System (ADS)
Sbierski, Björn; Madsen, Kevin A.; Brouwer, Piet W.; Karrasch, Christoph
2017-08-01
Disorder effects are especially pronounced around nodal points in linearly dispersing band structures as present in graphene or Weyl semimetals. Despite the enormous experimental and numerical progress, even a simple quantity like the average density of states cannot be assessed quantitatively by analytical means. We demonstrate how this important problem can be solved employing the functional renormalization group method, and, for the two-dimensional case, we demonstrate excellent agreement with reference data from numerical simulations based on tight-binding models. In three dimensions our analytic results also improve drastically on existing approaches.
Nodal lines and nodal loops in nonsymmorphic odd-parity superconductors
Micklitz, T.; Norman, M. R.
2017-01-01
We discuss the nodal structure of odd-parity superconductors in the presence of nonsymmorphic crystal symmetries, both with and without spin-orbit coupling, and with and without time-reversal symmetry. We comment on the relation of our work to previous work in the literature, and also the implications for unconventional superconductors such as UPt3.
Nodal lines and nodal loops in nonsymmorphic odd-parity superconductors
NASA Astrophysics Data System (ADS)
Micklitz, T.; Norman, M. R.
2017-01-01
We discuss the nodal structure of odd-parity superconductors in the presence of nonsymmorphic crystal symmetries, both with and without spin-orbit coupling, and with and without time-reversal symmetry. We comment on the relation of our work to previous work in the literature, and also the implications for unconventional superconductors such as UPt3.
New Anti-Nodal Monoclonal Antibodies Targeting the Nodal Pre-Helix Loop Involved in Cripto-1 Binding
Focà, Annalia; Sanguigno, Luca; Focà, Giuseppina; Strizzi, Luigi; Iannitti, Roberta; Palumbo, Rosanna; Hendrix, Mary J. C.; Leonardi, Antonio; Ruvo, Menotti; Sandomenico, Annamaria
2015-01-01
Nodal is a potent embryonic morphogen belonging to the TGF-β superfamily. Typically, it also binds to the ALK4/ActRIIB receptor complex in the presence of the co-receptor Cripto-1. Nodal expression is physiologically restricted to embryonic tissues and human embryonic stem cells, is absent in normal cells but re-emerges in several human cancers, including melanoma, breast, and colon cancer. Our aim was to obtain mAbs able to recognize Nodal on a major CBR (Cripto-Binding-Region) site and to block the Cripto-1-mediated signalling. To achieve this, antibodies were raised against hNodal(44–67) and mAbs generated by the hybridoma technology. We have selected one mAb, named 3D1, which strongly associates with full-length rhNodal (KD 1.4 nM) and recognizes the endogenous protein in a panel of human melanoma cell lines by western blot and FACS analyses. 3D1 inhibits the Nodal-Cripto-1 binding and blocks Smad2/3 phosphorylation. Data suggest that inhibition of the Nodal-Cripto-1 axis is a valid therapeutic approach against melanoma and 3D1 is a promising and interesting agent for blocking Nodal-Cripto mediated tumor development. These findings increase the interest for Nodal as both a diagnostic and prognostic marker and as a potential new target for therapeutic intervention. PMID:26370966
A nodal integral method for the Fokker-Planck equation
McArdle, K.R.; Dorning, J.J. )
1989-01-01
The Fokker-Planck equation is important in the kinetic theory of plasmas for the description of long-range coulomb collisions of charged particles. Hence, it is used extensively in modeling fusion devices, such as magnetic mirrors and certain aspects of tokamaks. The authors have developed a nodal integral method (NIM) for the accurate numerical solution of the Fokker-Planck equation, applied it to test problems, and compared the results obtained with those obtained using a finite difference method (FDM). These comparisons show that the NIM is more accurate and more computationally efficient than the FDM, especially in the calculation of particle and energy leakages and when applied to more difficult test problems. The new method significantly extends ideas developed previously to more complicated partial differential equations (PDEs) in two important ways. Since the nonlinearities in the Fokker-Planck equation are considerably more complicated than those that arise in the Navier-Stokes equations and the Boussinesq equations, the NIM developed here extends the general technique farther into the nonlinear regime. Further, since the Fokker-Planck equation is singular at the origin in spherical velocity coordinates, the geometry relevant to most practical problems, special origin equations had to be developed for the computational elements adjacent to the v = 0 boundary.
Nodal signaling and the evolution of deuterostome gastrulation.
Chea, Helen K; Wright, Christopher V; Swalla, Billie J
2005-10-01
Chordates, including vertebrates, evolved within a group of animals called the deuterostomes. All holoblastic deuterostomes gastrulate at the vegetal pole and the blastopore becomes the anus, while a mouth is formed at the anterior or to the oral side. Nodal is a member of the TGF-beta superfamily of signaling molecules that are important in signaling between cells during many embryonic processes in vertebrate embryos. Nodal has also been found in other invertebrate deuterostomes, such as ascidians and sea urchins, but, so far, is missing in protostomes. Nodal has been shown to be particularly important in determining left-right asymmetries in vertebrate embryos, but less information is available for its developmental role in the invertebrate deuterostomes. We review gastrulation in the deuterostomes, then examine nodal expression early during mesoderm formation and later during the establishment of asymmetries in both vertebrates and invertebrates. Nodal is expressed asymmetrically on the left side in chordates and on the presumptive oral side of the embryo in echinoid echinoderms. The expression of nodal is in different germ layers in embryos of different phyla. Expression is in the ectoderm in most of the invertebrate deuterostomes, and in the mesoderm in vertebrates. We summarize the work that has been published to date, especially nodal expression in the invertebrate deuterostomes, and suggest future experiments to better understand the evolution of nodal signaling and deuterostome gastrulation.
Market redesign and technology upgrade: a nodal implementation
Isemonger, Alan G.
2009-10-15
The California ISO and its market participants collectively cut over to a new nodal-based market on April 1, largely without incident and 11 years to the day from the initial startup in 1998. Thus far, the new nodal framework has proven robust, and the inevitable design and implementation issues that have emerged since cutover have been manageable. (author)
Topological nodal line semimetals predicted from first-principles calculations
NASA Astrophysics Data System (ADS)
Yu, Rui; Fang, Zhong; Dai, Xi; Weng, Hongming
2017-06-01
Topological semimetals are newly discovered states of quantum matter, which have extended the concept of topological states from insulators to metals and attracted great research interest in recent years. In general, there are three kinds of topological semimetals, namely Dirac semimetals, Weyl semimetals, and nodal line semimetals. Nodal line semimetals can be considered as precursor states for other topological states. For example, starting from such nodal line states, the nodal line structure might evolve into Weyl points, convert into Dirac points, or become a topological insulator by introducing the spin-orbit coupling (SOC) or mass term. In this review paper, we introduce theoretical materials that show the nodal line semimetal state, including the all-carbon Mackay-Terrones crystal (MTC), anti-perovskite Cu3PdN, pressed black phosphorus, and the CaP3 family of materials, and we present the design principles for obtaining such novel states of matter.
Radar response from vegetation with nodal structure
NASA Technical Reports Server (NTRS)
Blanchard, B. J.; Oneill, P. E.
1984-01-01
Radar images from the SEASAT synthetic aperture radar (SAR) produced unusually high returns from corn and sorghum fields, which seem to indicate a correlation between nodal separation in the stalk and the wavelength of the radar. These images also show no difference in return from standing or harvested corn. Further investigation using images from the Shuttle Imaging Radar (SIR-A) substantiated these observations and showed a degradation of the high return with time after harvest. From portions of corn and sweet sorghum stalks that were sampled to measure stalk water content, it was determined that near and after maturity the water becomes more concentrated in the stalk nodes. The stalk then becomes a linear sequence of alternating dielectrics as opposed to a long slender cylinder with uniform dielectric properties.
Experience with advanced nodal codes at YAEC
Cacciapouti, R.J.
1990-01-01
Yankee Atomic Electric Company (YAEC) has been performing reload licensing analysis since 1969. The basic pressurized water reactor (PWR) methodology involves the use of LEOPARD for cross-section generation, PDQ for radial power distributions and integral control rod worth, and SIMULATE for axial power distributions and differential control rod worth. In 1980, YAEC began performing reload licensing analysis for the Vermont Yankee boiling water reactor (BWR). The basic BWR methodology involves the use of CASMO for cross-section generation and SIMULATE for three-dimensional power distributions. In 1986, YAEC began investigating the use of CASMO-3 for cross-section generation and the advanced nodal code SIMULATE-3 for power distribution analysis. Based on the evaluation, the CASMO-3/SIMULATE-3 methodology satisfied all requirements. After careful consideration, the cost of implementing the new methodology is expected to be offset by reduced computing costs, improved engineering productivity, and fuel-cycle performance gains.
Effect of multiple-nodal basin drainage on cutaneous melanoma.
Federico, Andrea C; Chagpar, Anees B; Ross, Merrick I; Martin, Robert C G; Noyes, R Dirk; Goydos, James S; Beitsch, Peter D; Urist, Marshall M; Ariyan, Stephan; Sussman, Jeffrey J; McMasters, Kelly M; Scoggins, Charles R
2008-07-01
The number of nodal basins draining a primary cutaneous melanoma is not an independent predictor of outcome. Post hoc analysis of patients entered into a randomized, prospective study. Multi-institutional academic and community medical centers. Patients aged 18 to 70 years with melanoma 1.0 mm or greater Breslow thickness. Wide local excision and sentinel lymph node biopsy were performed on all patients; patients with sentinel lymph node metastases underwent completion lymphadenectomy. Patients with multiple-nodal basin drainage were compared with those with single-nodal basin drainage. Sentinel lymph node status, locoregional recurrence-free survival, disease-free survival, and overall survival. A total of 2060 patients with single-nodal basin drainage (n = 1709 [83% of cohort]) were included in the analysis, with a median follow-up of 50 months. On univariate analysis, the group with multiple-nodal basin drainage (n = 351) was associated with female sex and primary tumor regression (P < .001). In addition, multiple-nodal basin drainage was associated with truncal primary tumor location (73.2%), while single-nodal basin drainage was more common for extremity tumors (50.9%; P < .001). On multivariate analysis, there were no differences in the rate of sentinel lymph node metastasis, disease-free survival, or overall survival between the groups. Interestingly, locoregional recurrence was significantly worse in the single-nodal basin drainage group (P = .003). Multiple-nodal basin drainage does not confer a worse prognosis for patients with cutaneous melanoma. In fact, single-nodal basin drainage appears to be associated with a greater risk of locoregional recurrence.
Santarelli, P; Sosa, E; Denes, P
1982-01-01
A case is described with clinical and electrocardiographic findings of incessant junctional reciprocating tachycardia. Electrophysiological study showed that longitudinal dissociation of the atrioventricular node into two pathways was responsible for the maintenance of the arrhythmia. The two intranodal pathways had different refractory periods but reciprocally related and overlapping conduction times (anterograde fast, retrograde slow, and vice versa). Induction and termination of the arrhythmia was related to the presence of a partial atrio-nodal bypass tract. Images PMID:7082510
Topological semimetals with a double-helix nodal link
NASA Astrophysics Data System (ADS)
Chen, Wei; Lu, Hai-Zhou; Hou, Jing-Min
2017-07-01
Topological nodal line semimetals are characterized by the crossing of the conduction and valence bands along one or more closed loops in the Brillouin zone. Usually, these loops are either isolated or touch each other at some highly symmetric points. Here, we introduce a different kind of nodal line semimetal, that contains a pair of linked nodal loops. A concrete two-band model was constructed, which supports a pair of nodal lines with a double-helix structure, which can be further twisted into a Hopf link because of the periodicity of the Brillouin zone. The nodal lines are stabilized by the combined spatial inversion P and time reversal T symmetry; the individual P and T symmetries must be broken. The band exhibits nontrivial topology that each nodal loop carries a π Berry flux. Surface flatbands emerge at the open boundary and are exactly encircled by the projection of the nodal lines on the surface Brillouin zone. The experimental implementation of our model using cold atoms in optical lattices is discussed.
Esquivies, Luis; Blackler, Alissa; Peran, Macarena; Rodriguez-Esteban, Concepcion; Izpisua Belmonte, Juan Carlos; Booker, Evan; Gray, Peter C.; Ahn, Chihoon; Kwiatkowski, Witek; Choe, Senyon
2014-01-01
Nodal, a member of the TGF-β superfamily, plays an important role in vertebrate and invertebrate early development. The biochemical study of Nodal and its signaling pathway has been a challenge, mainly because of difficulties in producing the protein in sufficient quantities. We have developed a library of stable, chemically refoldable Nodal/BMP2 chimeric ligands (NB2 library). Three chimeras, named NB250, NB260, and NB264, show Nodal-like signaling properties including dependence on the co-receptor Cripto and activation of the Smad2 pathway. NB250, like Nodal, alters heart looping during the establishment of embryonic left-right asymmetry, and both NB250 and NB260, as well as Nodal, induce chondrogenic differentiation of human adipose-derived stem cells. This Nodal-induced differentiation is shown to be more efficient than BPM2-induced differentiation. Interestingly, the crystal structure of NB250 shows a backbone scaffold similar to that of BMP2. Our results show that these chimeric ligands may have therapeutic implications in cartilage injuries. PMID:24311780
The genetics of nodal marginal zone lymphoma
Spina, Valeria; Khiabanian, Hossein; Messina, Monica; Monti, Sara; Cascione, Luciano; Bruscaggin, Alessio; Spaccarotella, Elisa; Holmes, Antony B.; Arcaini, Luca; Lucioni, Marco; Tabbò, Fabrizio; Zairis, Sakellarios; Diop, Fary; Cerri, Michaela; Chiaretti, Sabina; Marasca, Roberto; Ponzoni, Maurilio; Deaglio, Silvia; Ramponi, Antonio; Tiacci, Enrico; Pasqualucci, Laura; Paulli, Marco; Falini, Brunangelo; Inghirami, Giorgio; Bertoni, Francesco; Foà, Robin; Rabadan, Raul; Gaidano, Gianluca
2016-01-01
Nodal marginal zone lymphoma (NMZL) is a rare, indolent B-cell tumor that is distinguished from splenic marginal zone lymphoma (SMZL) by the different pattern of dissemination. NMZL still lacks distinct markers and remains orphan of specific cancer gene lesions. By combining whole-exome sequencing, targeted sequencing of tumor-related genes, whole-transcriptome sequencing, and high-resolution single nucleotide polymorphism array analysis, we aimed at disclosing the pathways that are molecularly deregulated in NMZL and we compare the molecular profile of NMZL with that of SMZL. These analyses identified a distinctive pattern of nonsilent somatic lesions in NMZL. In 35 NMZL patients, 41 genes were found recurrently affected in ≥3 (9%) cases, including highly prevalent molecular lesions of MLL2 (also known as KMT2D; 34%), PTPRD (20%), NOTCH2 (20%), and KLF2 (17%). Mutations of PTPRD, a receptor-type protein tyrosine phosphatase regulating cell growth, were enriched in NMZL across mature B-cell tumors, functionally caused the loss of the phosphatase activity of PTPRD, and were associated with cell-cycle transcriptional program deregulation and increased proliferation index in NMZL. Although NMZL shared with SMZL a common mutation profile, NMZL harbored PTPRD lesions that were otherwise absent in SMZL. Collectively, these findings provide new insights into the genetics of NMZL, identify PTPRD lesions as a novel marker for this lymphoma across mature B-cell tumors, and support the distinction of NMZL as an independent clinicopathologic entity within the current lymphoma classification. PMID:27335277
Primary nodal hemangiosarcoma in four dogs.
Chan, Catherine M; Zwahlen, Courtney H; de Lorimier, Louis-Philippe; Yeomans, Stephen M; Hoffmann, Karon L; Moore, Antony S
2016-11-01
CASE DESCRIPTION 4 dogs with a slow-growing mass in the cervical region were evaluated. CLINICAL FINDINGS All dogs had no clinical signs at the time of the evaluation. There was no apparent evidence of visceral metastases or other primary tumor based on available CT or MRI data for any dog. TREATMENT AND OUTCOME For each dog, surgery to remove the mass was performed. Histologic examination of the excised tissue revealed a completely excised grade 1 or 2 lymph node hemangiosarcoma. All dogs received adjuvant chemotherapy; 2 dogs underwent curative intent chemotherapy, 1 dog underwent metronomic treatment with cyclophosphamide, and 1 dog underwent metronomic treatment with chlorambucil. The survival time was 259 days in 1 dog; 3 dogs were still alive 615, 399, and 365 days after surgery. CLINICAL RELEVANCE Primary nodal hemangiosarcoma in dogs is a rare and, to the authors' knowledge, previously undescribed disease that appears to develop in the cervical lymph nodes as a slow-growing mass or masses. Surgical excision and adjunct treatment resulted in long survival times for 3 of the 4 dogs of the present report. Given the aggressive biologic behavior of hemangiosarcomas in other body locations, adjunct chemotherapy should be considered for affected dogs, although its role in the cases described in this report was unclear. Additional clinical information is required to further characterize the biologic behavior of this tumor type and determine the expected survival times and associated risk factors in dogs.
Nodal Solutions for Supercritical Laplace Equations
NASA Astrophysics Data System (ADS)
Dalbono, Francesca; Franca, Matteo
2016-11-01
In this paper we study radial solutions for the following equation Δ u(x)+f (u(x), |x|) = 0, where {x in {Rn}}, n > 2, f is subcritical for r small and u large and supercritical for r large and u small, with respect to the Sobolev critical exponent {2^{*} = 2n/n-2}. The solutions are classified and characterized by their asymptotic behaviour and nodal properties. In an appropriate super-linear setting, we give an asymptotic condition sufficient to guarantee the existence of at least one ground state with fast decay with exactly j zeroes for any j ≥ 0. Under the same assumptions, we also find uncountably many ground states with slow decay, singular ground states with fast decay and singular ground states with slow decay, all of them with exactly j zeroes. Our approach, based on Fowler transformation and invariant manifold theory, enables us to deal with a wide family of potentials allowing spatial inhomogeneity and a quite general dependence on u. In particular, for the Matukuma-type potential, we show a kind of structural stability.
Josephson, Mark E
2016-01-01
Atrioventricular nodal reentrant tachycardia (AVNRT) should be classified as typical or atypical. The term ‘fast-slow AVNRT’ is rather misleading. Retrograde atrial activation during tachycardia should not be relied upon as a diagnostic criterion. Both typical and atypical atrioventricular nodal reentrant tachycardia are compatible with varying retrograde atrial activation patterns. Attempts at establishing the presence of a ‘lower common pathway’ are probably of no practical significance. When the diagnosis of AVNRT is established, ablation should be only directed towards the anatomic position of the slow pathway. If right septal attempts are unsuccessful, the left septal side should be tried. Ablation targeting earliest atrial activation sites during typical atrioventricular nodal reentrant tachycardia or the fast pathway in general for any kind of typical or atypical atrioventricular nodal reentrant tachycardia, are not justified. In this review we discuss current concepts about the tachycardia circuit, electrophysiologic diagnosis, and ablation of this arrhythmia. PMID:27617092
Adaptive Nodal Transport Methods for Reactor Transient Analysis
Thomas Downar; E. Lewis
2005-08-31
Develop methods for adaptively treating the angular, spatial, and time dependence of the neutron flux in reactor transient analysis. These methods were demonstrated in the DOE transport nodal code VARIANT and the US NRC spatial kinetics code, PARCS.
Nodal aberration theory for wild-filed asymmetric optical systems
NASA Astrophysics Data System (ADS)
Chen, Yang; Cheng, Xuemin; Hao, Qun
2016-10-01
Nodal Aberration Theory (NAT) was used to calculate the zero field position in Full Field Display (FFD) for the given aberration term. Aiming at wide-filed non-rotational symmetric decentered optical systems, we have presented the nodal geography behavior of the family of third-order and fifth-order aberrations. Meanwhile, we have calculated the wavefront aberration expressions when one optical element in the system is tilted, which was not at the entrance pupil. By using a three-piece-cellphone lens example in optical design software CodeV, the nodal geography is testified under several situations; and the wavefront aberrations are calculated when the optical element is tilted. The properties of the nodal aberrations are analyzed by using Fringe Zernike coefficients, which are directly related with the wavefront aberration terms and usually obtained by real ray trace and wavefront surface fitting.
Polynomial expansion nodal transport method in hexagonal geometry
Cho, Jin Young; Kim, Chang Hyo; Noh, Taewan
1997-12-01
Recently, the polynomial expansion nodal (PEN) method was developed as a new nodal diffusion scheme for hexagonal core analyses. Using the direct polynomial expansion for the node flux, the PEN method not only eliminates the complicated transverse integration procedures-especially in hexagonal geometry-which are frequently used in conventional nodal methods, but also provides a number of features such as the convenient energy group expendability and much enhanced accuracy with less computational effort. In this paper, we further develop the PEN method for the transport equation for the cases where the transport effects are important: highly heterogeneous, small (high-leakage), and fast reactors, etc. Here, we take the even-parity form of transport equation. The main reason is that the diffusion-like nature of the even-parity equation is adequate to establish the new nodal transport method (PEN-TR) using the earlier developed PEN method in diffusion theory.
Cilia and coordination of signaling networks during heart development
Koefoed, Karen; Veland, Iben Rønn; Pedersen, Lotte Bang; Larsen, Lars Allan; Christensen, Søren Tvorup
2014-01-01
Primary cilia are unique sensory organelles that coordinate a wide variety of different signaling pathways to control cellular processes during development and in tissue homeostasis. Defects in function or assembly of these antenna-like structures are therefore associated with a broad range of developmental disorders and diseases called ciliopathies. Recent studies have indicated a major role of different populations of cilia, including nodal and cardiac primary cilia, in coordinating heart development, and defects in these cilia are associated with congenital heart disease. Here, we present an overview of the role of nodal and cardiac primary cilia in heart development. PMID:24345806
Management of nodal recurrences of endometrial cancer with IMRT
Ho, Jennifer C.; Allen, Pamela K.; Jhingran, Anuja; Westin, Shannon N.; Lu, Karen H.; Eifel, Patricia J.; Klopp, Ann H.
2016-01-01
Objective Pelvic and paraortic lymph nodal regions are frequent sites of relapse in women with endometrial cancer who have not undergone adjuvant external beam radiation. We investigated outcomes after definitive management of nodal relapses of endometrial cancer with intensity modulated radiation therapy (IMRT). Methods Between 2002-2012, 38 patients with endometrial cancer who had no prior external beam radiation were treated definitively using IMRT for regionally confined pelvic or paraortic nodal recurrences. Thirteen (34%) had chemotherapy prior to radiation, and 21 (55%) received concurrent chemotherapy. The nodal basins were typically treated to 45-50 Gy, with a boost to the gross tumor to a median total of 64.7 Gy (range 59 – 73 Gy). Results The median overall survival from date of recurrence was 46.1 months and the 2-year survival was 71%. Patients who received concurrent chemotherapy had a significantly longer median survival (61.9 months versus 28.7 months, p=0.034). In-field failures were more frequent in patients who received chemotherapy prior to radiation, had a shorter recurrence-free interval, received a lower radiation dose, and had higher tumor grade. Three patients (8%) experienced grade 3-4 late gastrointestinal (GI) toxicity. Conclusions Long-term survival can be achieved in women with nodal recurrences of endometrial cancer. The use of concurrent chemotherapy and dose escalation with IMRT as feasible may improve survival for women with isolated nodal recurrences of endometrial cancer. PMID:26193429
Management of nodal recurrences of endometrial cancer with IMRT.
Ho, Jennifer C; Allen, Pamela K; Jhingran, Anuja; Westin, Shannon N; Lu, Karen H; Eifel, Patricia J; Klopp, Ann H
2015-10-01
Pelvic and paraortic lymph nodal regions are frequent sites of relapse in women with endometrial cancer who have not undergone adjuvant external beam radiation. We investigated outcomes after definitive management of nodal relapses of endometrial cancer with intensity modulated radiation therapy (IMRT). Between 2002-2012, 38 patients with endometrial cancer who had no prior external beam radiation were treated definitively using IMRT for regionally confined pelvic or paraortic nodal recurrences. Thirteen (34%) had chemotherapy prior to radiation, and 21 (55%) received concurrent chemotherapy. The nodal basins were typically treated to 45-50Gy, with a boost to the gross tumor to a median total of 64.7Gy (range 59-73Gy). The median overall survival from date of recurrence was 46.1months and the 2-year survival was 71%. Patients who received concurrent chemotherapy had a significantly longer median survival (61.9months versus 28.7months, p=0.034). In-field failures were more frequent in patients who received chemotherapy prior to radiation, had a shorter recurrence-free interval, received a lower radiation dose, and had higher tumor grade. Three patients (8%) experienced grade 3-4 late gastrointestinal (GI) toxicity. Long-term survival can be achieved in women with nodal recurrences of endometrial cancer. The use of concurrent chemotherapy and dose escalation with IMRT as feasible may improve survival for women with isolated nodal recurrences of endometrial cancer. Copyright © 2015 Elsevier Inc. All rights reserved.
Nodal signalling and asymmetry of the nervous system.
Signore, Iskra A; Palma, Karina; Concha, Miguel L
2016-12-19
The role of Nodal signalling in nervous system asymmetry is still poorly understood. Here, we review and discuss how asymmetric Nodal signalling controls the ontogeny of nervous system asymmetry using a comparative developmental perspective. A detailed analysis of asymmetry in ascidians and fishes reveals a critical context-dependency of Nodal function and emphasizes that bilaterally paired and midline-unpaired structures/organs behave as different entities. We propose a conceptual framework to dissect the developmental function of Nodal as asymmetry inducer and laterality modulator in the nervous system, which can be used to study other types of body and visceral organ asymmetries. Using insights from developmental biology, we also present novel evolutionary hypotheses on how Nodal led the evolution of directional asymmetry in the brain, with a particular focus on the epithalamus. We intend this paper to provide a synthesis on how Nodal signalling controls left-right asymmetry of the nervous system.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
Frederick N. Gleicher II; Abderrafi M. Ougouag
2009-09-01
A new diffusion-transport hybrid nodal method in R-Z is presented that can effectively treat non-multiplying zones in pebble bed reactors. The new method seamlessly combines the analytic coarse mesh finite difference (CMFD) diffusion formulation and a transport theory based response matrix formulation while retaining the properties and structure of the CMFD diffusion solver. The resulting combined formulation is utilized in selected non-multiplying nodes to capture angular effects on the flux. Test results indicate that the method has been implemented correctly into the CYNOD reactor kinetics code. This document also presents a status report on the development of a better source approximation for the Green’s function nodal solution in the radial direction of cylindrical geometry. The basic theory has been developed, including obtaining polynomials that are orthonormal over the domain of integration and the derivation of approximately half of the required matrix elements (single and double integrals in the source expansions).
The genetics of nodal marginal zone lymphoma.
Spina, Valeria; Khiabanian, Hossein; Messina, Monica; Monti, Sara; Cascione, Luciano; Bruscaggin, Alessio; Spaccarotella, Elisa; Holmes, Antony B; Arcaini, Luca; Lucioni, Marco; Tabbò, Fabrizio; Zairis, Sakellarios; Diop, Fary; Cerri, Michaela; Chiaretti, Sabina; Marasca, Roberto; Ponzoni, Maurilio; Deaglio, Silvia; Ramponi, Antonio; Tiacci, Enrico; Pasqualucci, Laura; Paulli, Marco; Falini, Brunangelo; Inghirami, Giorgio; Bertoni, Francesco; Foà, Robin; Rabadan, Raul; Gaidano, Gianluca; Rossi, Davide
2016-09-08
Nodal marginal zone lymphoma (NMZL) is a rare, indolent B-cell tumor that is distinguished from splenic marginal zone lymphoma (SMZL) by the different pattern of dissemination. NMZL still lacks distinct markers and remains orphan of specific cancer gene lesions. By combining whole-exome sequencing, targeted sequencing of tumor-related genes, whole-transcriptome sequencing, and high-resolution single nucleotide polymorphism array analysis, we aimed at disclosing the pathways that are molecularly deregulated in NMZL and we compare the molecular profile of NMZL with that of SMZL. These analyses identified a distinctive pattern of nonsilent somatic lesions in NMZL. In 35 NMZL patients, 41 genes were found recurrently affected in ≥3 (9%) cases, including highly prevalent molecular lesions of MLL2 (also known as KMT2D; 34%), PTPRD (20%), NOTCH2 (20%), and KLF2 (17%). Mutations of PTPRD, a receptor-type protein tyrosine phosphatase regulating cell growth, were enriched in NMZL across mature B-cell tumors, functionally caused the loss of the phosphatase activity of PTPRD, and were associated with cell-cycle transcriptional program deregulation and increased proliferation index in NMZL. Although NMZL shared with SMZL a common mutation profile, NMZL harbored PTPRD lesions that were otherwise absent in SMZL. Collectively, these findings provide new insights into the genetics of NMZL, identify PTPRD lesions as a novel marker for this lymphoma across mature B-cell tumors, and support the distinction of NMZL as an independent clinicopathologic entity within the current lymphoma classification. © 2016 by The American Society of Hematology.
Regional nodal irradiation in the conservative treatment of breast cancer
Haffty, B.G.; Fischer, D.; Fischer, J.J. )
1990-10-01
At this institution conservative treatment of breast cancer was begun in the 1960's. The following analysis represents our experience through 1984 with specific reference to the management of the regional lymph nodes. A total of 432 patients with clinical stage I and II breast cancer were treated between 1962 and 1984 with lumpectomy and radiation therapy. The breast was treated with tangential fields to a median dose of 4800 cGy and electron conedown to a total tumor bed dose of 6400 cGy. Axillary dissection was not routinely performed, particularly in the earlier years. More recently, axillary dissection has been used with increasing frequency if it was felt that the results of the dissection would influence systemic treatment. One hundred eighty-seven patients (43%) underwent axillary dissection and routinely received regional nodal irradiation to the internal mammary and supraclavicular lymph nodes. Two hundred forty-five patients (57%) did not undergo axillary dissection and routinely received regional nodal irradiation to the internal mammary, supraclavicular, and entire axillary regions to a total median dose of 4600 cGy. As of May 1989 with a median follow-up of 7.5 years, there have been a total of 12 nodal failures for an actuarial nodal control rate of 97% at 5 years and 96% at 10 years. The actuarial 5-year regional nodal control rate was the same for both the group of patients receiving regional RT alone without axillary dissection and the group of patients receiving axillary dissection and supraclavicular/internal mammary radiation. There has been minimal morbidity associated with this treatment policy. We conclude that regional nodal irradiation, with or without axillary dissection, results in a high rate of regional nodal control and minimal treatment morbidity in patients undergoing conservative treatment of early stage breast cancer.
Cunnane, Marybeth; Kyriazidis, Natalia; Kamani, Dipti; Juliano, Amy F; Kelly, Hillary R; Curtin, Hugh D; Barber, Samuel R; Randolph, Gregory W
2017-10-01
To evaluate the effectiveness, reproducibility, and usability of our proposed nodal nomenclature and classification system employed for several years in our high-volume thyroid cancer unit, for the adequate localization and mapping of lymph nodes in thyroid cancer patients with extensive nodal disease. Retrospective review. Thirty-three thyroid cancer patients with extensive nodal disease treated from January 2004 to May 2013 were included in our study. Preoperative ultrasound and computed tomography scans of these patients were reanalyzed by blinded radiologists to investigate the feasibility for the assignment of abnormal lymph nodes to compartments defined in our proposed nodal classification system and to identify areas of difficulty in the assignment. Analysis of nodal localization revealed a discrepancy in compartment agreement between the two radiologists in the assignment of abnormal nodes in nine patients (9/33, 27%). In six patients (6/33, 18%), discrepancy existed in labeling paratracheal and pretracheal nodes. In three patients (3/33, 9%), disagreement arose in the classification of retrocarotid nodes into lateral versus central compartment. A further refinement of the definition of key borderline regions of the pretracheal versus paratracheal and retrocarotid regions of our classification improved the agreement and demonstrated a complete concordance (100%) amongst the reviewing radiologists. The proposed nodal classification system, derived specifically for differentiated thyroid carcinoma, with readily identifiable anatomic boundaries on imaging and at surgery, facilitates communication among multidisciplinary physicians and aids in creating a uniform and reproducible radiographic nodal map to guide surgical therapy. 4 Laryngoscope, 127:2429-2436, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.
Type-II nodal loops: Theory and material realization
NASA Astrophysics Data System (ADS)
Li, Si; Yu, Zhi-Ming; Liu, Ying; Guan, Shan; Wang, Shan-Shan; Zhang, Xiaoming; Yao, Yugui; Yang, Shengyuan A.
2017-08-01
A nodal loop appears when two bands, typically one electronlike and one holelike, are crossing each other linearly along a one-dimensional manifold in reciprocal space. Here, we propose a type of nodal loop which emerges from the crossing between two bands which are both electronlike (or holelike) along a certain direction. Close to any point on such a loop (dubbed as a type-II nodal loop), the linear spectrum is strongly tilted and tipped over along one transverse direction, leading to marked differences in magnetic, optical, and transport responses compared with conventional (type-I) nodal loops. We show that the compound K4P3 is an example that hosts a pair of type-II nodal loops close to the Fermi level. Each loop traverses the whole Brillouin zone, and hence can only be annihilated in a pair when symmetry is preserved. The symmetry and topological protections of the loops as well as the associated surface states are discussed.
AV nodal dual pathway electrophysiology and Wenckebach periodicity.
Zhang, Youhua; Mazgalev, Todor N
2011-11-01
The precise mechanism(s) governing the phenomenon of AV nodal Wenckebach periodicity is not fully elucidated. Currently 2 hypotheses, the decremental conduction and the Rosenbluethian step-delay, are most frequently used. We have provided new evidence that, in addition, dual pathway (DPW) electrophysiology is directly involved in the manifestation of AV nodal Wenckebach phenomenon. AV nodal cellular action potentials (APs) were recorded from 6 rabbit AV node preparations during standard A1A2 and incremental pacing protocols. His electrogram alternans, a validated index of DPW electrophysiology, was used to monitor fast (FP) and slow (SP) pathway conduction. The data were collected in intact AV nodes, as well as after SP ablation. In all studied hearts the Wenckebach cycle started with FP propagation, followed by transition to SP until its ultimate block. During this process complex cellular APs were observed, with decremental foot formations reflecting the fading FP and second depolarizations produced by the SP. In addition, the AV node cells exhibited a progressive loss in maximal diastolic membrane potential (MDP) due to incomplete repolarization. The pause created with the blocked Wenckebach beat was associated with restoration of MDP and reinitiation of the conduction cycle via the FP wavefront. DPW electrophysiology is dynamically involved in the development of AV nodal Wenckebach periodicity. In the intact AV node, the cycle starts with FP that is progressively weakened and then replaced by SP propagation, until block occurs. AV nodal SP modification did not eliminate Wenckebach periodicity but strongly affected its paradigm. © 2011 Wiley Periodicals, Inc.
Three-dimensional transport with variational nodal methods
Lewis, E.E.; Palmiotti, G.; Shalil, H.S.; Laurin-Kovitz, K.; Fanning, T.; Hanebutte, U.R.
1996-12-31
The development of the variational nodal method contained in the three-dimensional transport code VARIANT is reviewed. This Argonne National Laboratory code treats two- and three- dimensional multigroup problems with anisotropic scattering in hexagonal and Cartesian geometries. The methodology couples hybrid finite elements in space, which enforce nodal balance, with spherical harmonics expansions in angle. The resulting response matrix equations are solved by red-black or four-color iterations. Several enhancements to VARIANT are discussed: The simplified spherical harmonics option provides near spherical harmonic accuracy for many problems at a fraction of the cost. Adjoint and perturbation calculations are performed without the physical- and mathematical adjoint dichotomy appearing in other nodal methods. Heterogeneous node methods extend the problem classes to which the method may be applied. Computational strategies and trade-offs are discussed and possible future research directions are outlined.
On the Nodal Lines of Eisenstein Series on Schottky Surfaces
NASA Astrophysics Data System (ADS)
Jakobson, Dmitry; Naud, Frédéric
2017-04-01
On convex co-compact hyperbolic surfaces {X=Γ backslash H2}, we investigate the behavior of nodal curves of real valued Eisenstein series {F_λ(z,ξ)}, where {λ} is the spectral parameter, {ξ} the direction at infinity. Eisenstein series are (non-{L^2}) eigenfunctions of the Laplacian {Δ_X} satisfying {Δ_X F_λ=(1/4+λ^2)F_λ}. As {λ} goes to infinity (the high energy limit), we show that, for generic {ξ}, the number of intersections of nodal lines with any compact segment of geodesic grows like {λ}, up to multiplicative constants. Applications to the number of nodal domains inside the convex core of the surface are then derived.
Spin-Orbit Nodal Semimetals in the Layer Groups
NASA Astrophysics Data System (ADS)
Wieder, Benjamin; Kim, Youngkuk; Kane, Charles
Recent interest in point and line node semimetals has lead to the proposal and discovery of these phenomena in numerous systems. Frequently, though, these nodal systems are described in terms of individual properties reliant on specific space group intricacies or band-tuning conditions. Restricting ourselves to cases with strong spin-orbit interaction, we develop a more general framework which captures existing systems and predicts new examples of nodal materials. In many previously proposed systems, the three-dimensional nature of the space group has obscured key generalities. Therefore, we show how within our framework one can predict and characterize a diverse set of nodal phenomena even in two-dimensional systems constructed of three-dimensional sites, known as the ``Layer Groups''. Introducing a set of simple models, we characterize the allowed semimetallic structures in the layer groups and draw connections to analogous three-dimensional systems.
Distant nodal metastasis: is it always an unresectable disease?
Celotti, Andrea; Molfino, Sarah; Baggi, Paolo; Tarasconi, Antonio; Baronio, Gianluca; Arru, Luca; Gheza, Federico; Tiberio, Guido; Portolani, Nazario
2017-01-01
This article aims at analyzing the published literature concerning the treatment of patients with gastric cancer and distant nodal metastases, actually considered metastatic disease. A systematic search was undertaken using Medline, Embase, Cochrane and Web-of-Science libraries. No specific restriction on year of publication was used; preference was given to English papers. Both clinical series and literature reviews were selected. Only 11 papers address the issue of surgery for nodal basins outside the D2 dissection area. From these papers, in selected cases extended surgery may prove useful in prolonging survival, when a comprehensive therapeutic pathway including chemotherapy is scheduled. In conclusion, in presence of nodal metastases outside the loco-regional nodes, surgery may be considered for metastatic nodes in stations 13 and 16, in selected cases. PMID:28217751
A computational study of nodal-based tetrahedral element behavior.
Gullerud, Arne S.
2010-09-01
This report explores the behavior of nodal-based tetrahedral elements on six sample problems, and compares their solution to that of a corresponding hexahedral mesh. The problems demonstrate that while certain aspects of the solution field for the nodal-based tetrahedrons provide good quality results, the pressure field tends to be of poor quality. Results appear to be strongly affected by the connectivity of the tetrahedral elements. Simulations that rely on the pressure field, such as those which use material models that are dependent on the pressure (e.g. equation-of-state models), can generate erroneous results. Remeshing can also be strongly affected by these issues. The nodal-based test elements as they currently stand need to be used with caution to ensure that their numerical deficiencies do not adversely affect critical values of interest.
A transient, quadratic nodal method for triangular-Z geometry
DeLorey, T.F.
1993-06-01
Many systematically-derived nodal methods have been developed for Cartesian geometry due to the extensive interest in Light Water Reactors. These methods typically model the transverse-integrated flux as either an analytic or low order polynomial function of position within the node. Recently, quadratic nodal methods have been developed for R-Z and hexagonal geometry. A static and transient quadratic nodal method is developed for triangular-Z geometry. This development is particularly challenging because the quadratic expansion in each node must be performed between the node faces and the triangular points. As a consequence, in the 2-D plane, the flux and current at the points of the triangles must be treated. Quadratic nodal equations are solved using a non-linear iteration scheme, which utilizes the corrected, mesh-centered finite difference equations, and forces these equations to match the quadratic equations by computing discontinuity factors during the solution. Transient nodal equations are solved using the improved quasi-static method, which has been shown to be a very efficient solution method for transient problems. Several static problems are used to compare the quadratic nodal method to the Coarse Mesh Finite Difference (CMFD) method. The quadratic method is shown to give more accurate node-averaged fluxes. However, it appears that the method has difficulty predicting node leakages near reactor boundaries and severe material interfaces. The consequence is that the eigenvalue may be poorly predicted for certain reactor configurations. The transient methods are tested using a simple analytic test problem, a heterogeneous heavy water reactor benchmark problem, and three thermal hydraulic test problems. Results indicate that the transient methods have been implemented correctly.
Nodal Structure and the Partitioning of Equivalence Classes
Fields, Lanny; Watanabe-Rose, Mari
2008-01-01
By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of A→B→C→D→E→F were produced by training AB, BC, CD, DE, and EF. Then, unique responses were trained to the C and D stimuli in each class. The responses trained to C generalized to B and A, while the responses trained to D generalized to E and F. Thus, each 4-node 6-member equivalence class was bifurcated into two 3-member functional classes: A→B→C and D→E→F, with class membership precisely predicted by nodal structure. A final emergent relations test documented the intactness of the underlying 4-node 6-member equivalence classes. The coexistence of the interchangeability of stimuli in an equivalence class and the bifurcation of such a class in terms of nodal structure was explained in the following manner. The conditional discriminations that are used to establish a class also imposes a nodal structure on the stimuli in the class. Thus, the stimuli in the class acquire two sets of relational properties. If the format of a test trial allows only one response option per class, responding on those trials will be in accordance with class membership and will not express the effects of nodal distance. If the format of a test trial allows more than one response option per class, responding on those trials will be determined by the nodal structure of the class. Thus, the relational properties expressed by the stimuli in an equivalence class are determined by the discriminative function served by the format of a test trial. PMID:18540220
Regional Nodal Irradiation in Early-Stage Breast Cancer.
Whelan, Timothy J; Olivotto, Ivo A; Parulekar, Wendy R; Ackerman, Ida; Chua, Boon H; Nabid, Abdenour; Vallis, Katherine A; White, Julia R; Rousseau, Pierre; Fortin, Andre; Pierce, Lori J; Manchul, Lee; Chafe, Susan; Nolan, Maureen C; Craighead, Peter; Bowen, Julie; McCready, David R; Pritchard, Kathleen I; Gelmon, Karen; Murray, Yvonne; Chapman, Judy-Anne W; Chen, Bingshu E; Levine, Mark N
2015-07-23
Most women with breast cancer who undergo breast-conserving surgery receive whole-breast irradiation. We examined whether the addition of regional nodal irradiation to whole-breast irradiation improved outcomes. We randomly assigned women with node-positive or high-risk node-negative breast cancer who were treated with breast-conserving surgery and adjuvant systemic therapy to undergo either whole-breast irradiation plus regional nodal irradiation (including internal mammary, supraclavicular, and axillary lymph nodes) (nodal-irradiation group) or whole-breast irradiation alone (control group). The primary outcome was overall survival. Secondary outcomes were disease-free survival, isolated locoregional disease-free survival, and distant disease-free survival. Between March 2000 and February 2007, a total of 1832 women were assigned to the nodal-irradiation group or the control group (916 women in each group). The median follow-up was 9.5 years. At the 10-year follow-up, there was no significant between-group difference in survival, with a rate of 82.8% in the nodal-irradiation group and 81.8% in the control group (hazard ratio, 0.91; 95% confidence interval [CI], 0.72 to 1.13; P=0.38). The rates of disease-free survival were 82.0% in the nodal-irradiation group and 77.0% in the control group (hazard ratio, 0.76; 95% CI, 0.61 to 0.94; P=0.01). Patients in the nodal-irradiation group had higher rates of grade 2 or greater acute pneumonitis (1.2% vs. 0.2%, P=0.01) and lymphedema (8.4% vs. 4.5%, P=0.001). Among women with node-positive or high-risk node-negative breast cancer, the addition of regional nodal irradiation to whole-breast irradiation did not improve overall survival but reduced the rate of breast-cancer recurrence. (Funded by the Canadian Cancer Society Research Institute and others; MA.20 ClinicalTrials.gov number, NCT00005957.).
Preoperative staging of nodal status in gastric cancer
Berlth, Felix; Chon, Seung-Hun; Chevallay, Mickael; Jung, Minoa Karin
2017-01-01
An accurate preoperative staging of nodal status is crucial in gastric cancer, because it has a great impact on prognosis and therapeutic decision-making. Different staging methods have been evaluated for gastric cancer in order to predict nodal involvement. So far, no technique could meet the necessary requirements, which include a high detection rate of infiltrated lymph nodes and a low frequency of false-positive results. This article summarizes different staging methods used to assess lymph node status in patients with gastric cancer, evaluates the evidence, and proposes to establish new methods. PMID:28217758
Regional Nodal Irradiation in Early-Stage Breast Cancer
Whelan, Timothy J.; Olivotto, Ivo A.; Parulekar, Wendy R.; Ackerman, Ida; Chua, Boon H.; Nabid, Abdenour; Vallis, Katherine A.; White, Julia R.; Rousseau, Pierre; Fortin, Andre; Pierce, Lori J.; Manchul, Lee; Chafe, Susan; Nolan, Maureen C.; Craighead, Peter; Bowen, Julie; McCready, David R.; Pritchard, Kathleen I.; Gelmon, Karen; Murray, Yvonne; Chapman, Judy-Anne W.; Chen, Bingshu E.; Levine, Mark N.
2015-01-01
BACKGROUND Most women with breast cancer who undergo breast-conserving surgery receive whole-breast irradiation. We examined whether the addition of regional nodal irradiation to whole-breast irradiation improved outcomes. METHODS We randomly assigned women with node-positive or high-risk node-negative breast cancer who were treated with breast-conserving surgery and adjuvant systemic therapy to undergo either whole-breast irradiation plus regional nodal irradiation (including internal mammary, supraclavicular, and axillary lymph nodes) (nodal-irradiation group) or whole-breast irradiation alone (control group). The primary outcome was overall survival. Secondary outcomes were disease-free survival, isolated locoregional disease-free survival, and distant disease-free survival. RESULTS Between March 2000 and February 2007, a total of 1832 women were assigned to the nodal-irradiation group or the control group (916 women in each group). The median follow-up was 9.5 years. At the 10-year follow-up, there was no significant between-group difference in survival, with a rate of 82.8% in the nodal-irradiation group and 81.8% in the control group (hazard ratio, 0.91; 95% confidence interval [CI], 0.72 to 1.13; P = 0.38). The rates of disease-free survival were 82.0% in the nodal-irradiation group and 77.0% in the control group (hazard ratio, 0.76; 95% CI, 0.61 to 0.94; P = 0.01). Patients in the nodal-irradiation group had higher rates of grade 2 or greater acute pneumonitis (1.2% vs. 0.2%, P = 0.01) and lymphedema (8.4% vs. 4.5%, P = 0.001). CONCLUSIONS Among women with node-positive or high-risk node-negative breast cancer, the addition of regional nodal irradiation to whole-breast irradiation did not improve overall survival but reduced the rate of breast-cancer recurrence. PMID:26200977
Nodal metastases in thyroid cancer: prognostic implications and management.
Wang, Laura Y; Ganly, Ian
2016-04-01
The significance of cervical lymph node metastases in differentiated thyroid cancer has been controversial and continues to evolve. Current staging systems consider nodal metastases to confer a poorer prognosis, particularly in older patients. Increasingly, the literature suggests that characteristics of the metastatic lymph nodes such as size and number are also prognostic. There is a growing trend toward less aggressive treatment of low-volume nodal disease. The aim of this review is to summarize the current literature and discuss prognostic and management implications of lymph node metastases in differentiated thyroid cancer.
Chiral Spin-Orbital Liquids with Nodal Lines
NASA Astrophysics Data System (ADS)
Natori, W. M. H.; Andrade, E. C.; Miranda, E.; Pereira, R. G.
2016-07-01
Strongly correlated materials with strong spin-orbit coupling hold promise for realizing topological phases with fractionalized excitations. Here, we propose a chiral spin-orbital liquid as a stable phase of a realistic model for heavy-element double perovskites. This spin liquid state has Majorana fermion excitations with a gapless spectrum characterized by nodal lines along the edges of the Brillouin zone. We show that the nodal lines are topological defects of a non-Abelian Berry connection and that the system exhibits dispersing surface states. We discuss some experimental signatures of this state and compare them with properties of the spin liquid candidate Ba2YMoO6.
Nodal metastases in thyroid cancer: prognostic implications and management
Wang, Laura Y; Ganly, Ian
2016-01-01
The significance of cervical lymph node metastases in differentiated thyroid cancer has been controversial and continues to evolve. Current staging systems consider nodal metastases to confer a poorer prognosis, particularly in older patients. Increasingly, the literature suggests that characteristics of the metastatic lymph nodes such as size and number are also prognostic. There is a growing trend toward less aggressive treatment of low-volume nodal disease. The aim of this review is to summarize the current literature and discuss prognostic and management implications of lymph node metastases in differentiated thyroid cancer. PMID:26948758
Universal phase transition and band structures for spinless nodal-line and Weyl semimetals
NASA Astrophysics Data System (ADS)
Okugawa, Ryo; Murakami, Shuichi
2017-09-01
We study a general phase transition between spinless topological nodal-line semimetal and Weyl semimetal phases. We classify topological nodal lines into two types based on their positions and shapes, and their phase transitions depend on their types. We show that a topological nodal-line semimetal becomes a Weyl semimetal by breaking time-reversal symmetry when the nodal lines enclose time-reversal-invariant momenta (type-A nodal lines). We also discuss an effect of crystallographic symmetries determining the band structure of the topological nodal-line semimetals. Thanks to protection by the symmetries, the topological nodal-line semimetals can transition into spinless Weyl semimetals or maintain the nodal lines in many crystals after inversion symmetry is broken.
Nodal Structure and the Partitioning of Equivalence Classes
ERIC Educational Resources Information Center
Fields, Lanny; Watanabe-Rose, Mari
2008-01-01
By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of…
PoroTomo Subtask 6.3 Nodal Seismometers Metadata
Lesley Parker
2016-03-28
Metadata for the nodal seismometer array deployed at the POROTOMO's Natural Laboratory in Brady Hot Spring, Nevada during the March 2016 testing. Metadata includes location and timing for each instrument as well as file lists of data to be uploaded in a separate submission.
Nodal Structure and the Partitioning of Equivalence Classes
ERIC Educational Resources Information Center
Fields, Lanny; Watanabe-Rose, Mari
2008-01-01
By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of…
The Penn State Nodal Expansion Transient Analysis Technique with thermal-hydraulic feedback
Borkowski, J.; Bandini, B.; Baratta, A. )
1989-11-01
The nuclear engineering department of the Pennsylvania State University has under development a nodal neutron kinetics code. The PEnn State Nodal Expansion TRansient Analysis TEchnique (PENETRATE) performs two-group, three-dimensional nodal kinetics calculations using the nodal expansion method (NEM). The focus of this discussion is its performance in the solution of the Langenbuch-Maurer-Werner light water rector (LMW LWR) problem. This transient requires an accurate model of both control rod motion and coupled thermal-hydraulic feedback.
Functional mathematical model of dual pathway AV nodal conduction.
Climent, A M; Guillem, M S; Zhang, Y; Millet, J; Mazgalev, T N
2011-04-01
Dual atrioventricular (AV) nodal pathway physiology is described as two different wave fronts that propagate from the atria to the His bundle: one with a longer effective refractory period [fast pathway (FP)] and a second with a shorter effective refractory period [slow pathway (SP)]. By using His electrogram alternance, we have developed a mathematical model of AV conduction that incorporates dual AV nodal pathway physiology. Experiments were performed on five rabbit atrial-AV nodal preparations to develop and test the presented model. His electrogram alternances from the inferior margin of the His bundle were used to identify fast and slow wave front propagations. The ability to predict AV conduction time and the interaction between FP and SP wave fronts have been analyzed during regular and irregular atrial rhythms (e.g., atrial fibrillation). In addition, the role of dual AV nodal pathway wave fronts in the generation of Wenckebach periodicities has been illustrated. Finally, AV node ablative modifications have been evaluated. The model accurately reproduced interactions between FP and SP during regular and irregular atrial pacing protocols. In all experiments, specificity and sensitivity higher than 85% were obtained in the prediction of the pathway responsible for conduction. It has been shown that, during atrial fibrillation, the SP ablation significantly increased the mean HH interval (204 ± 39 vs. 274 ± 50 ms, P < 0.05), whereas FP ablation did not produce significant slowing of ventricular rate. The presented mathematical model can help in understanding some of the intriguing AV node mechanisms and should be considered as a step forward in the studies of AV nodal conduction.
Phonon analog of topological nodal semimetals
NASA Astrophysics Data System (ADS)
Po, Hoi Chun; Bahri, Yasaman; Vishwanath, Ashvin
2016-05-01
Topological band structures in electronic systems like topological insulators and semimetals give rise to highly unusual physical properties. Analogous topological effects have also been discussed in bosonic systems, but the novel phenomena typically occur only when the system is excited by finite-frequency probes. A mapping recently proposed by C. L. Kane and T. C. Lubensky [Nat. Phys. 10, 39 (2014), 10.1038/nphys2835], however, establishes a closer correspondence. It relates the zero-frequency excitations of mechanical systems to topological zero modes of fermions that appear at the edges of an otherwise gapped system. Here we generalize the mapping to systems with an intrinsically gapless bulk. In particular, we construct mechanical counterparts of topological semimetals. The resulting gapless bulk modes are physically distinct from the usual acoustic Goldstone phonons and appear even in the absence of continuous translation invariance. Moreover, the zero-frequency phonon modes feature adjustable momenta and are topologically protected as long as the lattice coordination is unchanged. Such protected soft modes with tunable wave vector may be useful in designing mechanical structures with fault-tolerant properties.
47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 5 2010-10-01 2010-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...
47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 5 2012-10-01 2012-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...
47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 5 2014-10-01 2014-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...
47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 5 2011-10-01 2011-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...
47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 5 2013-10-01 2013-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...
Mitra, Nandita; Alonso-Basanta, Michelle; Adappa, Nithin D; Palmer, James N; O'Malley, Bert W; Rassekh, Christopher H; Chalian, Ara; Cohen, Roger B; Lin, Alexander
2016-01-01
Objective: Risk of nodal involvement in patients with sinonasal small-cell carcinoma and sinonasal undifferentiated carcinoma (SNUC) has not been well defined because of their rarity. We describe a population-based assessment of specific nodal level involvement in this group of rare neuroectodermal tumours. Methods: The Surveillance, Epidemiology and End Results (SEER) database from 2004 to 2011 identified patients with SNUC and sinonasal small-cell carcinoma. Overall neck involvement and individual nodal level involvement at presentation were assessed, and comparison was made with a contemporaneous cohort of patients with a borderline clinically significant risk of nodal involvement and recurrence. Results: Of 141 patients, 31 (22%) had gross nodal involvement at presentation (range 14–33% by site and histology). Non-nasal, non-ethmoid site with SNUC histology has the highest rates of initial nodal involvement, whereas higher stage and size do not predict for higher nodal involvement rates. Bilateral Levels 2–3 for all sinonasal small cell; Levels 2–3 for nasal or ethmoid SNUC; and bilateral Levels 1–3 in non-nasal/non-ethmoid SNUC have the highest rates of involvement compared with a clinical reference standard. Conclusion: We found high rates of initial nodal involvement in all SNUC and sinonasal small-cell carcinoma. We found higher initial involvement of Levels 2 and 3 and in certain cases to the Level 1 nodal levels, hypothesizing benefit for elective treatment to those levels. Advances in knowledge: With small single-institution series reporting conflicting nodal involvement rates, our data support high rates of nodal presentation at diagnosis, hypothesizing benefit for elective nodal treatment in this cohort. PMID:26559439
Thomas, Jonathan G; Kashani, Rojano; Balter, James M; Tatro, Daniel; Kong, Feng-Ming; Pan, Charlie C
2009-01-01
The purpose of this study was to determine the intra and interfraction motion of mediastinal lymph node regions. Ten patients with nonsmall-cell lung cancer underwent controlled inhale and exhale computed tomography (CT) scans during two sessions (40 total datasets) and mediastinal nodal stations 1-8 were outlined. Corresponding CT scans from different sessions were registered to remove setup error and, in this reference frame, the centroid of each nodal station was compared for right-left (RL), anterior-posterior (AP), and superior-inferior (SI) displacement. In addition, an anisotropic volume expansion encompassing the change of the nodal region margins in all directions was used. Intrafraction displacement was determined by comparing same session inhale-exhale scans. Interfraction reproducibility of nodal regions was determined by comparing the same respiratory phase scans between two sessions. Intrafraction displacement of centroid varied between nodal stations. All nodal regions moved posteriorly and superiorly with exhalation, and inferior nodal stations showed the most motion. Based on anisotropic expansion, nodal regions expanded mostly in the RL direction from inhale to exhale. The interpatient variations in intrafraction displacement were large compared with the displacements themselves. Moreover, there was substantial interfractional displacement ( approximately 5 mm). Mediastinal lymph node regions clearly move during breathing. In addition, deformation of nodal regions between inhale and exhale occurs. The degree of motion and deformation varies by station and by individual. This study indicates the potential advantage of characterizing individualized nodal region motion to safely maximize conformality of mediastinal nodal targets.
Ju, Guohao; Yan, Changxiang; Gu, Zhiyuan; Ma, Hongcai
2016-05-01
In active optics systems, one concern is how to quantitatively separate the effects of astigmatic and trefoil figure errors and misalignments that couple together in determining the total aberration fields when wavefront measurements are available at only a few field points. In this paper, we first quantitatively describe the impact of mount-induced trefoil deformation on the net aberration fields by proposing a modified theoretical formulation for the field-dependent aberration behavior of freeform surfaces based on the framework of nodal aberration theory. This formulation explicitly expresses the quantitative relationships between the magnitude of freeform surfaces and the induced aberration components where the freeform surfaces can be located away from the aperture stop and decentered from the optical axis. On this basis, and in combination with the mathematical presentation of nodal aberration theory for the effects of misalignments, we present the analytic expressions for the aberration fields of two-mirror telescopes in the presence of astigmatic primary mirror figure errors, mount-induced trefoil deformations on both mirrors, and misalignments. We quantitatively separate these effects using the analytical expressions with wavefront measurements at a few field points and pointing errors. Valuable insights are provided on how to separate these coupled effects in the computation process. Monte Carlo simulations are conducted to demonstrate the correctness and accuracy of the analytic method presented in this paper.
NASA Astrophysics Data System (ADS)
Tanaka, Satoyuki; Suzuki, Hirotaka; Sadamoto, Shota; Sannomaru, Shogo; Yu, Tiantang; Bui, Tinh Quoc
2016-08-01
Two-dimensional (2D) in-plane mixed-mode fracture mechanics problems are analyzed employing an efficient meshfree Galerkin method based on stabilized conforming nodal integration (SCNI). In this setting, the reproducing kernel function as meshfree interpolant is taken, while employing the SCNI for numerical integration of stiffness matrix in the Galerkin formulation. The strain components are smoothed and stabilized employing Gauss divergence theorem. The path-independent integral ( J-integral) is solved based on the nodal integration by summing the smoothed physical quantities and the segments of the contour integrals. In addition, mixed-mode stress intensity factors (SIFs) are extracted from the J-integral by decomposing the displacement and stress fields into symmetric and antisymmetric parts. The advantages and features of the present formulation and discretization in evaluation of the J-integral of in-plane 2D fracture problems are demonstrated through several representative numerical examples. The mixed-mode SIFs are evaluated and compared with reference solutions. The obtained results reveal high accuracy and good performance of the proposed meshfree method in the analysis of 2D fracture problems.
Off-diagonal Jacobian support for Nodal BCs
Peterson, John W.; Andrs, David; Gaston, Derek R.; Permann, Cody J.; Slaughter, Andrew E.
2015-01-01
In this brief note, we describe the implementation of o-diagonal Jacobian computations for nodal boundary conditions in the Multiphysics Object Oriented Simulation Environment (MOOSE) [1] framework. There are presently a number of applications [2{5] based on the MOOSE framework that solve complicated physical systems of partial dierential equations whose boundary conditions are often highly nonlinear. Accurately computing the on- and o-diagonal Jacobian and preconditioner entries associated to these constraints is crucial for enabling ecient numerical solvers in these applications. Two key ingredients are required for properly specifying the Jacobian contributions of nonlinear nodal boundary conditions in MOOSE and nite element codes in general: 1. The ability to zero out entire Jacobian matrix rows after \
Nodal failure index approach to groundwater remediation design
Lee, J.; Reeves, H.W.; Dowding, C.H.
2008-01-01
Computer simulations often are used to design and to optimize groundwater remediation systems. We present a new computationally efficient approach that calculates the reliability of remedial design at every location in a model domain with a single simulation. The estimated reliability and other model information are used to select a best remedial option for given site conditions, conceptual model, and available data. To evaluate design performance, we introduce the nodal failure index (NFI) to determine the number of nodal locations at which the probability of success is below the design requirement. The strength of the NFI approach is that selected areas of interest can be specified for analysis and the best remedial design determined for this target region. An example application of the NFI approach using a hypothetical model shows how the spatial distribution of reliability can be used for a decision support system in groundwater remediation design. ?? 2008 ASCE.
Anomalous contagion and renormalization in networks with nodal mobility
NASA Astrophysics Data System (ADS)
Manrique, Pedro D.; Qi, Hong; Zheng, Minzhang; Xu, Chen; Hui, Pak Ming; Johnson, Neil F.
2016-07-01
A common occurrence in everyday human activity is where people join, leave and possibly rejoin clusters of other individuals —whether this be online (e.g. social media communities) or in real space (e.g. popular meeting places such as cafes). In the steady state, the resulting interaction network would appear static over time if the identities of the nodes are ignored. Here we show that even in this static steady-state limit, a non-zero nodal mobility leads to a diverse set of outbreak profiles that is dramatically different from known forms, and yet matches well with recent real-world social outbreaks. We show how this complication of nodal mobility can be renormalized away for a particular class of networks.
Radial nodalization effects on BWR (boiling water reactor) stability calculations
March-Leuba, J.
1990-01-01
Computer simulations have shown that stability calculations in boiling water reactors (BWRs) are very sensitive to a number of input parameters and modeling assumptions. In particular, the number of thermohydraulic regions (i.e., channels) used in the calculation can affect the results of decay ratio calculations by as much as 30%. This paper presents the background theory behind the observed effects of radial nodalization in BWR stability calculations. The theory of how a radial power distribution can be simulated in time or frequency domain codes by using representative'' regions is developed. The approximations involved in this method of solution are reviewed, and some examples of the effect of radial nodalization are presented based on LAPUR code solutions. 2 refs., 4 figs., 2 tabs.
NODAL PATHWAY GENES ARE DOWNREGULATED IN FACIAL ASYMMETRY
Nicot, Romain; Hottenstein, Molly; Raoul, Gwenael; Ferri, Joel; Horton, Michael; Tobias, John W.; Barton, Elisabeth; Gelé, Patrick; Sciote, James J.
2014-01-01
Purpose Facial asymmetry is a common comorbid condition in patients with jaw deformation malocclusion. Heritability of malocclusion is advancing rapidly, but very little is known regarding genetic contributions to asymmetry. This study identifies differences in expression of key asymmetry-producing genes which are down regulated in facial asymmetry patients. Material and Methods Masseter muscle samples were collected during BSSO orthognathic surgery to correct skeletal-based malocclusion. Patients were classified as Class II or III and open or deep bite malocclusion with or without facial asymmetry. Muscle samples were analyzed for gene expression differences on Affymetrix HT2.0 microarray global expression chips. Results Overall gene expression was different for asymmetric patients compared to other malocclusion classifications by principal component analysis (P<0.05). We identified differences in the nodal signaling pathway (NSP) which promotes development of mesoderm and endoderm and left-right patterning during embryogenesis. Nodal and Lefty expression was 1.39–1.84 fold greater (P<3.41×10−5) whereas integral membrane Nodal-modulators Nomo1,2,3 were −5.63 to −5.81 (P<3.05×10−4) less in asymmetry subjects. Fold differences among intracellular pathway members were negative in the range of −7.02 to −2.47 (P<0.003). Finally Pitx2, a upstream effector of Nodal known to influence the size of type II skeletal muscle fibers was also significantly decreased in facial asymmetry (P<0.05). Conclusions When facial asymmetry is part of skeletal malocclusion there are decreases of NSP genes in masseter muscle. This data suggests that the NSP is down regulated to help promote development of asymmetry. Pitx2 expression differences also contributed to both skeletal and muscle development in this condition. PMID:25364968
PoroTomo: Nodal Seismometer Active Source Data Sample
Kurt Feigl
2016-03-25
This data is in sac format and includes recordings of two active source events from 238 three-component nodal seismometers deployed at Bradys Hot Springs geothermal field as part of the PoroTomo project. The source was a viberoseis truck operating in P-wave vibrational mode and generating a swept-frequency signal. The files are 33 seconds long starting 4 seconds before each sweep was initiated. There is some overlap in the file times.
Nodal equivalence theory for hexagonal geometry, thermal reactor analysis
Zika, M.; Downar, T. )
1992-01-01
An important aspect of advanced nodal methods is the determination of equivalent few-group parameters for the relatively large homogenized regions used in the nodal flux solution. The theoretical foundation for light water reactor (LWR) assembly homogenization methods has been clearly established, and during the last several years, its successes have secured its position in the stable of dependable LWR analysis methods. Groupwise discontinuity factors that correct for assembly homogenization errors are routinely generated along with the group constants during lattice physics analysis. During the last several years, there has been interest in applying equivalence theory to other reactor types and other geometries. A notable effort has been the work at Argonne National Laboratory to incorporate nodal equivalence theory (NET) for hexagonal lattices into the nodal diffusion option of the DIF3D code. This work was originally intended to improve the neutronics methods used for the analysis of the Experimental Breeder Reactor II (EBR-II), and Ref. 4 discusses the success of that application. More recently, however, attempts were made to apply NET to advanced, thermal reactor designs such as the modular high-temperature gas reactor (MHTGR) and the new production heavy water reactor (NPR/HWR). The same methods that were successful for EBR-II have encountered problems for these reactors. Our preliminary analysis indicates that the sharp global flux gradients in these cores requires large discontinuity factors (greater than 4 or 5) to reproduce the reference solution. This disrupts the convergence of the iterative methods used to solve for the node-wise flux moments and partial currents. Several attempts to remedy the problem have been made over the last few years, including bounding the discontinuity factors and providing improved initial guesses for the flux solution, but nothing has been satisfactory.
NASA Astrophysics Data System (ADS)
Shukla, K.; Wang, Y.; Jaiswal, P.
2014-12-01
In a porous medium the seismic energy not only propagates through matrix but also through pore-fluids. The differential movement between sediment grains of the matrix and interstitial fluid generates a diffusive wave which is commonly referred to as the slow P-wave. A combined system of equation which includes both elastic and diffusive phases is known as the poroelasticity. Analyzing seismic data through poroelastic modeling results in accurate interpretation of amplitude and separation of wave modes, leading to more accurate estimation of geomehanical properties of rocks. Despite its obvious multi-scale application, from sedimentary reservoir characterization to deep-earth fractured crust, poroelasticity remains under-developed primarily due to the complex nature of its constituent equations. We present a detail formulation of poroleastic wave equations for isotropic media by combining the Biot's and Newtonian mechanics. System of poroelastic wave equation constitutes for eight time dependent hyperbolic PDEs in 2D whereas in case of 3D number goes up to thirteen. Eigen decomposition of Jacobian of these systems confirms the presence of an additional slow-P wave phase with velocity lower than shear wave, posing stability issues on numerical scheme. To circumvent the issue, we derived a numerical scheme using nodal discontinuous Galerkin approach by adopting the triangular meshes in 2D which is extended to tetrahedral for 3D problems. In our nodal DG approach the basis function over a triangular element is interpolated using Legendre-Gauss-Lobatto (LGL) function leading to a more accurate local solutions than in the case of simple DG. We have tested the numerical scheme for poroelastic media in 1D and 2D case, and solution obtained for the systems offers high accuracy in results over other methods such as finite difference , finite volume and pseudo-spectral. The nodal nature of our approach makes it easy to convert the application into a multi-threaded algorithm
Histogenesis of metaplastic breast carcinoma and axillary nodal metastases.
Osako, Tomo; Horii, Rie; Ogiya, Akiko; Iijima, Kotaro; Iwase, Takuji; Akiyama, Futoshi
2009-02-01
A 40-year-old breast-feeding woman presented with left breast swelling. On physical examination a 7 cm mass was found in the breast. Because biopsy demonstrated malignant tissue, mastectomy with axillary nodal dissection was performed. Pathological findings were consistent with metaplastic breast carcinoma with nodal metastases. The primary tumor consisted of three types of invasion: ductal, squamous, and sarcomatous. Furthermore, three morphological transitions were observed: ductal-squamous, ductal-sarcomatous, and squamous-sarcomatous. Ductal-squamous (12/18 microscopy slides) and squamous-sarcomatous transitions (10/18) were more commonly observed than ductal-sarcomatous transition (3/18). Furthermore, immunohistochemistry showed loss of epithelial marker (cytokeratin) and acquisition of mesenchymal markers (vimentin and alpha-smooth muscle actin) in the sarcomatous component. These findings suggested that epithelial-mesenchymal transition had occurred in the tumor and that two pathways, ductal-squamous-sarcomatous and ductal-sarcomatous transition, were involved in progression of metaplastic breast carcinoma. The main pathway appeared to be ductal-squamous-sarcomatous transition. Regarding the nodal metastases, of 13 positive nodes, ductal, squamous, and sarcomatous components were observed in 13, seven, and two nodes, respectively. Moreover, as in the primary tumor, ductal-squamous and squamous-sarcomatous transitions were observed. This suggested that the ductal component metastasized to the nodes and that epithelial-mesenchymal transition subsequently occurred within the nodes.
LSST Telescope Alignment Plan Based on Nodal Aberration Theory
NASA Astrophysics Data System (ADS)
Sebag, J.; Gressler, W.; Schmid, T.; Rolland, J. P.; Thompson, K. P.
2012-04-01
The optical alignment of the Large Synoptic Survey Telescope (LSST) is potentially challenging, due to its fast three-mirror optical design and its large 3.5° field of view (FOV). It is highly advantageous to align the three-mirror optical system prior to the integration of the complex science camera on the telescope, which corrects the FOV via three refractive elements and includes the operational wavefront sensors. A telescope alignment method based on nodal aberration theory (NAT) is presented here to address this challenge. Without the science camera installed on the telescope, the on-axis imaging performance of the telescope is diffraction-limited, but the field of view is not corrected. The nodal properties of the three-mirror telescope design have been analyzed and an alignment approach has been developed using the intrinsically linear nodal behavior, which is linked via sensitivities to the misalignment parameters. Since mirror figure errors will exist in any real application, a methodology to introduce primary-mirror figure errors into the analysis has been developed and is also presented.
Anomalous scaling of the penetration depth in nodal superconductors
NASA Astrophysics Data System (ADS)
She, Jian-Huang; Lawler, Michael J.; Kim, Eun-Ah
2015-07-01
Recent findings of anomalous superlinear scaling of low-temperature (T ) penetration depth (PD) in several nodal superconductors near putative quantum critical points suggest that the low-temperature PD can be a useful probe of quantum critical fluctuations in a superconductor. On the other hand, cuprates, which are poster child nodal superconductors, have not shown any such anomalous scaling of PD, despite growing evidence of quantum critical points (QCP). Then it is natural to ask when and how can quantum critical fluctuations cause anomalous scaling of PD? Carrying out the renormalization group calculation for the problem of two-dimensional superconductors with point nodes, we show that quantum critical fluctuations associated with a point group symmetry reduction result in nonuniversal logarithmic corrections to the T dependence of the PD. The resulting apparent power law depends on the bare velocity anisotropy ratio. We then compare our results to data sets from two distinct nodal superconductors: YBa2Cu3O6.95 and CeCoIn5. Considering all symmetry-lowering possibilities of the point group of interest, C4 v, we find our results to be remarkably consistent with YBa2Cu3O6.95 being near a vertical nematic QCP and CeCoIn5 being near a diagonal nematic QCP. Our results motivate a search for diagonal nematic fluctuations in CeCoIn5.
Topological phase transitions in line-nodal superconductors
NASA Astrophysics Data System (ADS)
Han, SangEun; Cho, Gil Young; Moon, Eun-Gook
2017-03-01
Fathoming interplay between symmetry and topology of many-electron wave functions has deepened our understanding of quantum many-body systems, particularly after the discovery of topological insulators. Topology of electron wave functions often enforces and protects emergent gapless excitation, and symmetry is intrinsically tied to the topological protection of the excitations. Namely, unless the symmetry is broken, the topological nature of the excitations is intact. We show intriguing phenomena of interplay between symmetry and topology in three-dimensional topological phase transitions associated with line-nodal superconductors. More specifically, we discover an exotic universality class out of topological line-nodal superconductors. The order parameter of broken symmetries is strongly correlated with underlying line-nodal fermions, and this gives rise to a large anomalous dimension in sharp contrast to that of the Landau-Ginzburg theory. Remarkably, hyperscaling violation and emergent relativistic scaling appear in spite of the presence of nonrelativistic fermionic excitation. We also propose characteristic experimental signatures around the phase transitions, for example, a linear phase boundary in a temperature-tuning parameter phase diagram, and discuss the implication of recent experiments in pnictides and heavy-fermion systems.
Improved pressurized water reactor radial reflector modeling in nodal analysis
Mueller, E.Z. )
1991-10-01
A one-dimensional method based on a combination of the nodal equivalence theory and response matrix homogenization methods was previously described for determining environment-insensitive equivalent few-group diffusion theory parameters for homogenized radial reflector nodes of a pressurized water reactor. This reflector model, called the NGET-RM model, yields equivalent nodal parameters that do not account for the two-dimensional structure of the baffle at core corners; this can lead to significant errors in computed two-dimensional core power distributions. A semi-empirical correction procedure is proposed for reducing the two-dimensional effects associated with this particular one-dimensional reflector model. Numerical two-group experiments are performed for a given reflector configuration (and soluble boron concentration) to determine optimal values of the two empirical factors defined by this model. In this paper it is shown that the resultant factors are rather insensitive to core configuration or core conditions and that their application yields improved two-group NGET-RM reflector parameters with which accurate nodal power distributions can be obtained. The results are also compared with those obtained with another one-dimensional environment-insensitive model that has an extra degree of freedom utilized here to reduce two-dimensional effects. Some practical aspects related to the application of the proposed correction procedure are briefly discussed.
Topological Phase Transitions in Line-nodal Superconductors
NASA Astrophysics Data System (ADS)
Cho, Gil Young; Han, Sangeun; Moon, Eun-Gook
Fathoming interplay between symmetry and topology of many-electron wave-functions deepens our understanding in quantum nature of many particle systems. Topology often protects zero-energy excitation, and in a certain class, symmetry is intrinsically tied to the topological protection. Namely, unless symmetry is broken, topological nature is intact. We study one specific case of such class, symmetry-protected line-nodal superconductors in three spatial dimensions (3d). Mismatch between phase spaces of order parameter fluctuation and line-nodal fermion excitation induces an exotic universality class in a drastic contrast to one of the conventional ϕ4 theory in 3d. Hyper-scaling violation and relativistic dynamic scaling with unusually large quantum critical region are main characteristics, and their implication in experiments is discussed. For example, continuous phase transition out of line-nodal superconductors has a linear phase boundary in a temperature-tuning parameter phase-diagram. This work was supported by the Brain Korea 21 PLUS Project of Korea Government and KAIST start-up funding.
A nodal domain theorem for integrable billiards in two dimensions
Samajdar, Rhine; Jain, Sudhir R.
2014-12-15
Eigenfunctions of integrable planar billiards are studied — in particular, the number of nodal domains, ν of the eigenfunctions with Dirichlet boundary conditions are considered. The billiards for which the time-independent Schrödinger equation (Helmholtz equation) is separable admit trivial expressions for the number of domains. Here, we discover that for all separable and non-separable integrable billiards, ν satisfies certain difference equations. This has been possible because the eigenfunctions can be classified in families labelled by the same value of mmodkn, given a particular k, for a set of quantum numbers, m,n. Further, we observe that the patterns in a family are similar and the algebraic representation of the geometrical nodal patterns is found. Instances of this representation are explained in detail to understand the beauty of the patterns. This paper therefore presents a mathematical connection between integrable systems and difference equations. - Highlights: • We find that the number of nodal domains of eigenfunctions of integrable, planar billiards satisfy a class of difference equations. • The eigenfunctions labelled by quantum numbers (m,n) can be classified in terms of mmodkn. • A theorem is presented, realising algebraic representations of geometrical patterns exhibited by the domains. • This work presents a connection between integrable systems and difference equations.
High-order nodal discontinuous Galerkin methods for the Maxwell eigenvalue problem.
Hesthaven, J S; Warburton, T
2004-03-15
The Maxwell eigenvalue problem is known to pose difficulties for standard numerical methods, predominantly due to its large null space. As an alternative to the widespread use of Galerkin finite-element methods based on curl-conforming elements, we propose to use high-order nodal elements in a discontinuous element scheme. We consider both two- and three-dimensional problems and show the former to be without problems in a wide range of cases. Numerical experiments suggest the validity of this for general problems. For the three-dimensional eigenproblem, we encounter difficulties with a naive formulation of the scheme and propose minor modifications, intimately related to the discontinuous nature of the formulation, to overcome these concerns. We conclude by connecting the findings to time domain solution of Maxwell's equations. The discussion, analysis, and numerous computational experiments suggest that using discontinuous element schemes for solving Maxwell's equation in the frequency- or time-domain present a high-order accurate, efficient and robust alternative to classical Galerkin finite-element methods.
Cripto recruits Furin and PACE4 and controls Nodal trafficking during proteolytic maturation.
Blanchet, Marie-Hélène; Le Good, J Ann; Mesnard, Daniel; Oorschot, Viola; Baflast, Stéphane; Minchiotti, Gabriella; Klumperman, Judith; Constam, Daniel B
2008-10-08
The glycosylphosphatidylinositol (GPI)-anchored proteoglycan Cripto binds Nodal and its type I receptor Alk4 to activate Smad2,3 transcription factors, but a role during Nodal precursor processing has not been described. We show that Cripto also binds the proprotein convertases Furin and PACE4 and localizes Nodal processing at the cell surface. When coexpressed as in early embryonic cells, Cripto and uncleaved Nodal already associated during secretion, and a Cripto-interacting region in the Nodal propeptide potentiated the effect of proteolytic maturation on Nodal signalling. Disruption of the trans-Golgi network (TGN) by brefeldin A blocked secretion, but export of Cripto and Nodal to the cell surface was not inhibited, indicating that Nodal is exposed to extracellular convertases before entering the TGN/endosomal system. Density fractionation and antibody uptake experiments showed that Cripto guides the Nodal precursor in detergent-resistant membranes to endocytic microdomains marked by GFP-Flotillin. We conclude that Nodal processing and endocytosis are coupled in signal-receiving cells.
Guo, Qiang; Ning, Fen; Fang, Rui; Wang, Hong-Sheng; Zhang, Ge; Quan, Mei-Yu; Cai, Shao-Hui; Du, Jun
2015-01-01
Nodal, an important embryonic morphogen, has been reported to modulate tumorigenesis. Epithelial-mesenchymal transition (EMT) plays an important role in cancer metastasis. We have previously reported that recombinant Nodal treatment can promote melanoma undergoing EMT, but the effects of endogenous Nodal on EMT are still unknown. Here we generated both Nodal-overexpression and -knockdown stable cell lines to investigate the in vitro and in vivo characteristics of Nodal-induced EMT in murine melanoma cells. Nodal-overexpression cells displayed increased migration ability, accompanied by typical phenotype changes of EMT. In contrast, Nodal-knockdown stable cells repressed the EMT phenotype as well as reduced cell motility. Results of animal experiments confirmed that overexpression of Nodal can promote the metastasis of melanoma tumor in vivo. Mechanistically, we found that Nodal-induced expression of Snail and Slug involves its activation of ALK/Smads and PI3k/AKT pathways, which is an important process in the Nodal-induced EMT. However, we also found that the EMT phenotype was not completely inhibited by blocking the paracrine activity of Nodal in Nodal overexpression cell line suggesting the presence of additional mechanism(s) in the Nodal-induced EMT. This study provides a better understanding of Nodal function in melanoma, and suggests targeting Nodal as a potential strategy for melanoma therapey. PMID:26269769
Li, Xian-Ying; Hu, Shi-Min
2013-02-01
Harmonic functions are the critical points of a Dirichlet energy functional, the linear projections of conformal maps. They play an important role in computer graphics, particularly for gradient-domain image processing and shape-preserving geometric computation. We propose Poisson coordinates, a novel transfinite interpolation scheme based on the Poisson integral formula, as a rapid way to estimate a harmonic function on a certain domain with desired boundary values. Poisson coordinates are an extension of the Mean Value coordinates (MVCs) which inherit their linear precision, smoothness, and kernel positivity. We give explicit formulas for Poisson coordinates in both continuous and 2D discrete forms. Superior to MVCs, Poisson coordinates are proved to be pseudoharmonic (i.e., they reproduce harmonic functions on n-dimensional balls). Our experimental results show that Poisson coordinates have lower Dirichlet energies than MVCs on a number of typical 2D domains (particularly convex domains). As well as presenting a formula, our approach provides useful insights for further studies on coordinates-based interpolation and fast estimation of harmonic functions.
Response of millet and sorghum to a varying water supply around the primary and nodal roots.
Rostamza, M; Richards, R A; Watt, M
2013-07-01
Cereals have two root systems. The primary system originates from the embryo when the seed germinates and can support the plant until it produces grain. The nodal system can emerge from stem nodes throughout the plant's life; its value for yield is unclear and depends on the environment. The aim of this study was to test the role of nodal roots of sorghum and millet in plant growth in response to variation in soil moisture. Sorghum and millet were chosen as both are adapted to dry conditions. Sorghum and millet were grown in a split-pot system that allowed the primary and nodal roots to be watered separately. When primary and nodal roots were watered (12 % soil water content; SWC), millet nodal roots were seven times longer than those of sorghum and six times longer than millet plants in dry treatments, mainly from an 8-fold increase in branch root length. When soil was allowed to dry in both compartments, millet nodal roots responded and grew 20 % longer branch roots than in the well-watered control. Sorghum nodal roots were unchanged. When only primary roots received water, nodal roots of both species emerged and elongated into extremely dry soil (0.6-1.5 % SWC), possibly with phloem-delivered water from the primary roots in the moist inner pot. Nodal roots were thick, short, branchless and vertical, indicating a tropism that was more pronounced in millet. Total nodal root length increased in both species when the dry soil was covered with plastic, suggesting that stubble retention or leaf mulching could facilitate nodal roots reaching deeper moist layers in dry climates. Greater nodal root length in millet than in sorghum was associated with increased shoot biomass, water uptake and water use efficiency (shoot mass per water). Millet had a more plastic response than sorghum to moisture around the nodal roots due to (1) faster growth and progression through ontogeny for earlier nodal root branch length and (2) partitioning to nodal root length from primary roots
Topological nodal-line semimetal in nonsymmorphic Cmce -phase Ag2S
NASA Astrophysics Data System (ADS)
Huang, Huaqing; Jin, Kyung-Hwan; Liu, Feng
2017-09-01
Based on first-principles calculations and symmetry analysis, we discovery that the Ag2S with C m c e symmetry is a topological nodal-line semimetal in the absence of spin-orbit coupling. A single nodal loop as protected by the glide symmetry exists around the center of the Brillouin zone, dispersing slightly in the momentum space to form both electron and hole pockets around the loop. Moreover, a nearly flat drumheadlike surface state appears on the (001) surface of this material. The nodal-line semimetal phase and its drumheadlike surface states are expected to be experimentally detectable in C m c e -phase Ag2S because spin-orbit coupling will only open a negligible gap comparing to the energy dispersion of the nodal loop. Our finding provides a different member to the growing family of nodal-line semimetals with a single nodal loop structure.
Topological Dirac nodal lines and surface charges in fcc alkaline earth metals
NASA Astrophysics Data System (ADS)
Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi; Murakami, Shuichi
2017-01-01
In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin-orbit interaction is neglected. In particular, Ca becomes a nodal-line semimetal at high pressure. Owing to nodal lines, the Zak phase becomes either π or 0, depending on the wavevector k, and the π Zak phase leads to surface polarization charge. Carriers eventually screen it, leaving behind large surface dipoles. In materials with nodal lines, both the large surface polarization charge and the emergent drumhead surface states enhance Rashba splitting when heavy adatoms are present, as we have shown to occur in Bi/Sr(111) and in Bi/Ag(111).
Topological nodal line semimetals with and without spin-orbital coupling
NASA Astrophysics Data System (ADS)
Fang, Chen; Chen, Yige; Kee, Hae-Young; Fu, Liang
2015-08-01
We theoretically study three-dimensional topological semimetals (TSMs) with nodal lines protected by crystalline symmetries. Compared to TSMs with point nodes, e.g., Weyl semimetals and Dirac semimetals, where the conduction and the valence bands touch at discrete points, in these TSMs the two bands cross at closed lines in the Brillouin zone. We propose two different classes of symmetry protected nodal lines in the absence and in the presence of spin-orbital coupling (SOC), respectively. In the former, we discuss nodal lines that are protected by a combination of inversion symmetry and time-reversal symmetry, yet, unlike previously studied nodal lines in the same symmetry class, each nodal line has a Z2 monopole charge and can only be created (annihilated) in pairs. In the second class, with SOC, we show that a nonsymmorphic symmetry (screw axis) protects a four-band crossing nodal line in systems having both inversion and time-reversal symmetries.
Park, C B; Dufort, D
2011-03-01
Nodal, a secreted signaling protein in the transforming growth factor-beta (TGF-β) superfamily, has established roles in vertebrate development. However, components of the Nodal signaling pathway are also expressed at the maternal-fetal interface and have been implicated in many processes of mammalian reproduction. Emerging evidence indicates that Nodal and its extracellular inhibitor Lefty are expressed in the uterus and complex interactions between the two proteins mediate menstruation, decidualization and embryo implantation. Furthermore, several studies have shown that Nodal from both fetal and maternal sources may regulate trophoblast cell fate and facilitate placentation as both embryonic and uterine-specific Nodal knockout mouse strains exhibit disrupted placenta morphology. Here we review the established and prospective roles of Nodal signaling in facilitating successful pregnancy, including recent evidence supporting a potential link to parturition and preterm birth. Copyright © 2011 Elsevier Ltd. All rights reserved.
Topological Dirac nodal lines and surface charges in fcc alkaline earth metals.
Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi; Murakami, Shuichi
2017-01-11
In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin-orbit interaction is neglected. In particular, Ca becomes a nodal-line semimetal at high pressure. Owing to nodal lines, the Zak phase becomes either π or 0, depending on the wavevector k, and the π Zak phase leads to surface polarization charge. Carriers eventually screen it, leaving behind large surface dipoles. In materials with nodal lines, both the large surface polarization charge and the emergent drumhead surface states enhance Rashba splitting when heavy adatoms are present, as we have shown to occur in Bi/Sr(111) and in Bi/Ag(111).
A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality
NASA Astrophysics Data System (ADS)
Noël, Emily S.; Verhoeven, Manon; Lagendijk, Anne Karine; Tessadori, Federico; Smith, Kelly; Choorapoikayil, Suma; den Hertog, Jeroen; Bakkers, Jeroen
2013-11-01
Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind regulation of organ laterality. Here we identify a Nodal-independent mechanism that drives asymmetric heart looping in zebrafish embryos. In a unique mutant defective for the Nodal-related southpaw gene, preferential dextral looping in the heart is maintained, whereas gut and brain asymmetries are randomized. As genetic and pharmacological inhibition of Nodal signalling does not abolish heart asymmetry, a yet undiscovered mechanism controls heart chirality. This mechanism is tissue intrinsic, as explanted hearts maintain ex vivo retain chiral looping behaviour and require actin polymerization and myosin II activity. We find that Nodal signalling regulates actin gene expression, supporting a model in which Nodal signalling amplifies this tissue-intrinsic mechanism of heart looping.
Topological insulating phases from two-dimensional nodal loop semimetals
NASA Astrophysics Data System (ADS)
Li, Linhu; Araújo, Miguel A. N.
2016-10-01
Starting from a minimal model for a two-dimensional nodal loop semimetal, we study the effect of chiral mass gap terms. The resulting Dirac loop anomalous Hall insulator's Chern number is the phase-winding number of the mass gap terms on the loop. We provide simple lattice models, analyze the topological phases, and generalize a previous index characterizing topological transitions. The responses of the Dirac loop anomalous Hall and quantum spin Hall insulators to a magnetic field's vector potential are also studied both in weak- and strong-field regimes, as well as the edge states in a ribbon geometry.
Approximate Schur complement preconditioning of the lowest order nodal discretizations
Moulton, J.D.; Ascher, U.M.; Morel, J.E.
1996-12-31
Particular classes of nodal methods and mixed hybrid finite element methods lead to equivalent, robust and accurate discretizations of 2nd order elliptic PDEs. However, widespread popularity of these discretizations has been hindered by the awkward linear systems which result. The present work exploits this awkwardness, which provides a natural partitioning of the linear system, by defining two optimal preconditioners based on approximate Schur complements. Central to the optimal performance of these preconditioners is their sparsity structure which is compatible with Dendy`s black box multigrid code.
Evaluation of the use of nodal methods for MTR neutronic analysis
Reitsma, F.; Mueller, E.Z.
1997-08-01
Although modern nodal methods are used extensively in the nuclear power industry, their use for research reactor analysis has been very limited. The suitability of nodal methods for material testing reactor analysis is investigated with the emphasis on the modelling of the core region (fuel assemblies). The nodal approach`s performance is compared with that of the traditional finite-difference fine mesh approach. The advantages of using nodal methods coupled with integrated cross section generation systems are highlighted, especially with respect to data preparation, simplicity of use and the possibility of performing a great variety of reactor calculations subject to strict time limitations such as are required for the RERTR program.
Magnon nodal-line semimetals and drumhead surface states in anisotropic pyrochlore ferromagnets
NASA Astrophysics Data System (ADS)
Mook, Alexander; Henk, Jürgen; Mertig, Ingrid
2017-01-01
We introduce a type of topological magnon matter: the magnonic pendant to electronic nodal-line semimetals. Magnon spectra of anisotropic pyrochlore ferromagnets feature twofold degeneracies of magnon bands along a closed loop in reciprocal space. These magnon nodal lines are topologically protected by the coexistence of inversion and time-reversal symmetry; they require the absence of spin-orbit interaction (no Dzyaloshinskii-Moriya interaction). We calculate the topological invariants of the nodal lines and show that details of the associated magnon drumhead surface states depend strongly on the termination of the surface. Magnon nodal-line semimetals complete the family of topological magnons in three-dimensional ferromagnetic materials.
Radiotherapy studies and extra-nodal non-Hodgkin lymphomas, progress and challenges.
Specht, L
2012-06-01
Extra-nodal lymphomas may arise in any organ, and different histological subtypes occur in distinct patterns. Prognosis and treatment depend not only on the histological subtype and disease extent, but also on the particular involved extra-nodal organ. The clinical course and response to treatment for the more common extra-nodal organs, e.g. stomach, Waldeyer's ring, skin and brain, are fairly well known and show significant variation. A few randomised trials have been carried out testing the role of radiotherapy in these lymphomas. However, for most extra-nodal lymphomas, randomised trials have not been carried out, and treatment decisions are made on small patient series and extrapolations from nodal lymphomas. Hopefully, wide international collaboration will make controlled clinical trials possible in the less common extra-nodal lymphomas. Modern highly conformal radiotherapy allows better coverage of extra-nodal lymphomatous involvement with better sparing of normal tissues. The necessary radiation doses and volumes need to be defined for the different extra-nodal lymphoma entities. The challenge is to optimise the use of radiotherapy in the modern multimodality treatment of extra-nodal lymphomas.
Pseudospin Vortex Ring with a Nodal Line in Three Dimensions
NASA Astrophysics Data System (ADS)
Lim, Lih-King; Moessner, Roderich
2017-01-01
We present a model of a topological semimetal in three dimensions whose energy spectrum exhibits a nodal line acting as a vortex ring; this in turn is linked by a pseudospin structure akin to that of a smoke ring. Contrary to a Weyl point node spectrum, the vortex ring gives rise to Skyrmionic pseudospin patterns in cuts on both sides of the nodal ring plane; this pattern covers the full Brillouin zone, thus leading to a fully extended chiral Fermi arc and a new, "maximal," anomalous Hall effect in a 3D semimetal. Tuning a model parameter shrinks the vortex ring until it vanishes, giving way to a pair of Weyl nodes of opposite chirality. This establishes a connection between two distinct momentum-space topologies—that of a vortex ring (a circle of singularity) and a monopole-antimonopole pair (two point singularities). We present the model both as a low-energy continuum and a two-band tight-binding lattice model. Its simplicity permits an analytical computation of its Landau level spectrum.
Symmetry Breaking in a Model for Nodal Cilia
NASA Astrophysics Data System (ADS)
Brokaw, Charles J.
2005-03-01
Nodal cilia are very short cilia found in the embryonic node on the ventral surface of early mammalian embryos. They create a right to left fluid flow that is responsible for determining the normal asymmetry of the internal organs of the mammalian body. To do this, the distal end of the cilium must circle in a counterclockwise sense. Computer simulations with 3-dimensional models of flagella allow examination of 3-dimensional movements such as those of nodal cilia. 3-dimensional circling motions of short cilia can be achieved with velocity controlled models, in which dynein activity is regulated by sliding velocity. If dyneins on one outer doublet are controlled by the sliding velocity experienced by that doublet, the system is symmetric, and the 3-dimensional models can show either clockwise or counterclockwise circling. My computer simulations have examined two possible symmetry breaking mechanisms: 1) dyneins on doublet N are regulated by a mixture of the sliding velocities experienced by doublets N and N+1 (numbered in a clockwise direction, looking from the base). or 2) symmetry is broken by an off-axis force that produces a right-handed twist of the axoneme, consistent with observations that some dyneins can rotate their substrate microtubules in a clockwise direction.
Amyloid precursor protein at node of Ranvier modulates nodal formation
Xu, De-En; Zhang, Wen-Min; Yang, Zara Zhuyun; Zhu, Hong-Mei; Yan, Ke; Li, Shao; Bagnard, Dominique; Dawe, Gavin S; Ma, Quan-Hong; Xiao, Zhi-Cheng
2014-01-01
Amyloid precursor protein (APP), commonly associated with Alzheimer disease, is upregulated and distributes evenly along the injured axons, and therefore, also known as a marker of demyelinating axonal injury and axonal degeneration. However, the physiological distribution and function of APP along myelinated axons was unknown. We report that APP aggregates at nodes of Ranvier (NOR) in the myelinated central nervous system (CNS) axons but not in the peripheral nervous system (PNS). At CNS NORs, APP expression co-localizes with tenascin-R and is flanked by juxtaparanodal potassium channel expression demonstrating that APP localized to NOR. In APP-knockout (KO) mice, nodal length is significantly increased, while sodium channels are still clustered at NORs. Moreover, APP KO and APP-overexpressing transgenic (APP TG) mice exhibited a decreased and an increased thickness of myelin in spinal cords, respectively, although the changes are limited in comparison to their littermate WT mice. The thickness of myelin in APP KO sciatic nerve also increased in comparison to that in WT mice. Our observations indicate that APP acts as a novel component at CNS NORs, modulating nodal formation and has minor effects in promoting myelination. PMID:25482638
Dirac Magnon Nodal Loops in Quasi-2D Quantum Magnets.
Owerre, S A
2017-07-31
In this report, we propose a new concept of one-dimensional (1D) closed lines of Dirac magnon nodes in two-dimensional (2D) momentum space of quasi-2D quantum magnetic systems. They are termed "2D Dirac magnon nodal-line loops". We utilize the bilayer honeycomb ferromagnets with intralayer coupling J and interlayer coupling J L , which is realizable in the honeycomb chromium compounds CrX3 (X ≡ Br, Cl, and I). However, our results can also exist in other layered quasi-2D quantum magnetic systems. Here, we show that the magnon bands of the bilayer honeycomb ferromagnets overlap for J L ≠ 0 and form 1D closed lines of Dirac magnon nodes in 2D momentum space. The 2D Dirac magnon nodal-line loops are topologically protected by inversion and time-reversal symmetry. Furthermore, we show that they are robust against weak Dzyaloshinskii-Moriya interaction Δ DM < J L and possess chiral magnon edge modes.
Tumor satellite in predicting occult nodal metastasis of tongue cancer.
Yang, Tsung-Lin; Lou, Pei-Jen; Chang, Yih-Leong; Wu, Chen-Tu; Wang, Cheng-Ping; Ko, Jenq-Yuh
2011-10-01
Tongue cancer is well known to have a high potential for locoregional metastasis. However, controversy about electively treating the neck in early-stage tongue cancer remains. Although many risk factors related to cervical occult nodal metastasis (ONM) have been investigated, the ability of the tumor to spread, a phenomenon that results from the intrinsic property of the tumor and its interaction with the surrounding environment, has seldom been addressed. Retrospective case series with chart review. Tertiary referral hospital of university. Patients with early-stage squamous cell carcinoma of the oral tongue. In 71 eligible enrolled patients, ONM was detected in 19 (27%) patients, while the results were negative (ONM(-)) in 52 (73%) patients. The average tumor satellite distance (TSD) in the ONM(+) group was 4.1 ± 4.3 mm, in contrast to that in the ONM(-) group (1.0 ± 1.5 mm; P < .001). When stratified by increased TSD values, the significance of the difference between the 2 groups increased. For clinical applications, the optimal TSD threshold for determining the ONM probability was 3.5 mm. Multivariate analyses demonstrated that TSD was an independent prognosticator. The results indicate that TSD is a feasible pathological parameter that is useful for determining the status of cervical nodal metastasis. It can be used as an indicator of potential cervical subclinical disease and as a guideline for deciding the necessity and modality of neck treatment.
Nodal Diffusion Burnable Poison Treatment for Prismatic Reactor Cores
A. M. Ougouag; R. M. Ferrer
2010-10-01
The prismatic block version of the High Temperature Reactor (HTR) considered as a candidate Very High Temperature Reactor (VHTR)design may use burnable poison pins in locations at some corners of the fuel blocks (i.e., assembly equivalent structures). The presence of any highly absorbing materials, such as these burnable poisons, within fuel blocks for hexagonal geometry, graphite-moderated High Temperature Reactors (HTRs) causes a local inter-block flux depression that most nodal diffusion-based method have failed to properly model or otherwise represent. The location of these burnable poisons near vertices results in an asymmetry in the morphology of the assemblies (or blocks). Hence the resulting inadequacy of traditional homogenization methods, as these “spread” the actually local effect of the burnable poisons throughout the assembly. Furthermore, the actual effect of the burnable poison is primarily local with influence in its immediate vicinity, which happens to include a small region within the same assembly as well as similar regions in the adjacent assemblies. Traditional homogenization methods miss this artifact entirely. This paper presents a novel method for treating the local effect of the burnable poison explicitly in the context of a modern nodal method.
Thomas, Jonathan G.; Kashani, Rojano; Balter, James M.; Tatro, Daniel; Kong, Feng-Ming; Pan, Charlie C.
2009-01-01
Purpose/Objective The purpose of this study is to determine the intra- and inter-fraction motion of mediastinal lymph node regions. Materials/Methods Ten patients with non-small cell lung cancer underwent controlled inhale and exhale CT scans during two sessions (40 total data sets) and mediastinal nodal stations 1–8 [Chapet, et al, IJROBP 2005;63:170–8] were outlined. Corresponding CT scans from different sessions were registered to remove setup error and in this reference frame, the center-of-mass (COM) of each nodal station was compared for right-left (RL), anterior-posterior (AP), and superior-inferior (SI) displacement. In addition, an anisotropic volume expansion encompassing the change of the nodal region margins in all directions was used. Intra-fraction displacement was determined by comparing same session inhale-exhale scans. Inter-fraction reproducibility of nodal regions was determined by comparing the same respiratory phase scans between two sessions. Results Intra-fraction displacement of COM varied between nodal stations. All nodal regions moved posteriorly and superiorly with exhalation, and inferior nodal stations showed the most motion. Based on anisotropic expansion, nodal regions expanded mostly in the RL direction from inhale to exhale. The inter-patient variations in intra-fraction displacement were large compared to the displacements themselves. Moreover, there was substantial inter-fractional displacement (∼5 mm). Conclusions Mediastinal lymph node regions clearly move during breathing. Additionally, deformation of nodal regions between inhale and exhale occurs. The degree of motion and deformation varies by station and by individual. This study indicates the potential advantage of characterizing individualized nodal region motion to safely maximize conformality of mediastinal nodal targets. PMID:19410142
The impact of audit and feedback on nodal harvest in colorectal cancer
2011-01-01
Background Adequate nodal harvest (≥ 12 lymph nodes) in colorectal cancer has been shown to optimize staging and proposed as a quality indicator of colorectal cancer care. An audit within a single health district in Nova Scotia, Canada presented and published in 2002, revealed that adequate nodal harvest occurred in only 22% of patients. The goal of this current study was to identify factors associated with adequate nodal harvest, and specifically to examine the impact of the audit and feedback strategy on nodal harvest. Methods This population-based study included all patients undergoing resection for primary colorectal cancer in Nova Scotia, Canada, from 01 January 2001 to 31 December 2005. Linkage of the provincial cancer registry with other databases (hospital discharge, physician claims data, and national census data) provided clinicodemographic, diagnostic, and treatment-event data. Factors associated with adequate nodal harvest were examined using multivariate logistic regression. The specific interaction between year and health district was examined to identify any potential effect of dissemination of the previously-performed audit. Results Among the 2,322 patients, the median nodal harvest was 8; overall, 719 (31%) had an adequate nodal harvest. On multivariate analysis, audited health district (p < 0.0001), year (p < 0.0001), younger age (p < 0.0001), non-emergent surgery (p < 0.0001), more advanced stage (p = 0.008), and previous cancer history (p = 0.03) were associated with an increased likelihood of an adequate nodal harvest. Interaction between year and audited health district was identified (p = 0.006) such that the increase in adequate nodal harvest over time was significantly greater in the audited health district. Conclusions Improvements in colorectal cancer nodal harvest did occur over time. A published audit demonstrating suboptimal nodal harvest appeared to be an effective knowledge translation tool, though more so for the audited health
Von Neumann stability analysis of the u- p reproducing kernel formulation for saturated porous media
NASA Astrophysics Data System (ADS)
Chi, Sheng-Wei; Siriaksorn, Thanakorn; Lin, Shih-Po
2017-02-01
This paper introduces the von Neumann method to investigate the temporal stability of the displacement-pressure (u{-}p) reproducing kernel formulation for saturated porous media. Both dynamic and quasi-static formulations are considered and the critical time steps are derived. The effect of lumped and consistent matrices on temporal stability is analyzed under explicit temporal discretization. It is shown that lumped matrices have better temporal stability than consistent matrices. The study also shows that nodal support size greatly affects the critical time step size of the formulations. For consistent matrices, larger support size results in smaller critical time step size; however, opposite relation occurs if lumped scheme is used. The numerical study shows that stabilization parameter of the stabilized nodal integration methods reduces the critical time step size. Transient analyses are performed to verify the results from von Neumann analysis.
Luo, Yijun; Liu, Yuhui; Wang, Xiaoli; Zhang, Bin; Yu, Jinming; Wang, Chengang; Huang, Yong
2016-01-01
Background To map detail distribution of metastatic supraclavicular (SCV) lymph nodes (LN) in esophageal cancer (EC) patients and determine the precise radiation therapy clinical target volume (CTV). Methods A total of 101 thoracic esophageal carcinoma patients after surgery experienced SCV LN metastasis were retrospectively examined. The SCV region is further divided into four subgroups. Using hand drawings registration, nodes were mapped to a template computed tomogram to provide a visual impression of nodal frequencies and anatomic distribution. Results In all, 158 nodes were considered to be clinical metastatic in the SCV region in the 101 patients, 74 on the left and 84 on the right. Seven of 158 (4.4%) positive LN were located in group I, 78 of 158 (49.37%) were located in group II, 72 of 158 nodes (45.6%) were located in group III, 1 of 158 (0.63%) located in group IV. Conclusions According to our results, the SCV group II and group III are considered to be the high risk regions of esophageal squamous cell carcinoma (ESCC) LN metastasis, which were defined as elective nodal irradiation (ENI) areas. PMID:28066592
ERIC Educational Resources Information Center
CLEAVES, PAUL C.; AND OTHERS
THE INSTRUCTIONAL MATERIALS CENTER IS LOCATED IN THE LOCAL HIGH SCHOOL AND SUPPLIES ALL SCHOOLS IN THE AREA. AUDIOVISUAL EQUIPMENT ORDERS, AFTER SELECTIONS ARE MADE BY THE CLASSROOM TEACHER, ARE PROCESSED BY THE CENTER, CONFIRMED AND DELIVERED BY TRUCK THREE TIMES EACH WEEK. EACH SCHOOL HAS A BUILDING COORDINATOR WHO CHECKS THE ORDERS INTO THE…
ERIC Educational Resources Information Center
CLEAVES, PAUL C.; AND OTHERS
THE INSTRUCTIONAL MATERIALS CENTER IS LOCATED IN THE LOCAL HIGH SCHOOL AND SUPPLIES ALL SCHOOLS IN THE AREA. AUDIOVISUAL EQUIPMENT ORDERS, AFTER SELECTIONS ARE MADE BY THE CLASSROOM TEACHER, ARE PROCESSED BY THE CENTER, CONFIRMED AND DELIVERED BY TRUCK THREE TIMES EACH WEEK. EACH SCHOOL HAS A BUILDING COORDINATOR WHO CHECKS THE ORDERS INTO THE…
Prevention of AV Nodal Reentry Tachycardia by Oral Amiodarone: An Alternative Mechanism of Action
Gold, Robert L.; Haffajee, Charles I.; Entes, Kenneth L.
1987-01-01
A 73-year-old man was noted to have atrioventricular (AV) nodal reentry tachycardia, which was induced during programmed electrical stimulation. After 1 month of oral amiodarone therapy, AV nodal reentry tachycardia was prevented by the prolongation of atrial refractoriness and not by direct action on the AV node itself. (Texas Heart Institute Journal 1987; 14:99-101) PMID:15227337
Gale, Robert Peter; Wang, Li; Xu, Ji; Qu, Xiao-Yan; Fan, Lei; Li, Tian-Lv; Li, Jian-Yong; Xu, Wei
2017-01-01
We analyzed data from 54 newly-diagnosed persons with extra-nodal natural killer/T-cell (NK/T) lymphoma, who had a pretreatment 18F-FDG PET/CT study, to determine whether the sum of SUVmax of all the nodal and extra-nodal lesions predicted progression-free survival (PFS) and/or overall survival (OS). Three models (WB1SUVmax, WB2SUVmax, WB3SUVmax) based on the basis of the sum of SUVmax of the whole-body SUVmax of 11 nodal and 10 extra-nodal lesions were tested. The discrimination value of these models was evaluated using time-dependent receiver-operator characteristic (ROC) curves and corresponding areas under the curve (AUC) in training and validation cohorts. Findings were validated in an independent cohort of 15 subjects. ROC curve analysis showed the optimal cut-off values for WB1SUVmax, WB2SUVmax and WB3SUVmax were 15.8 (sensitivity 92%, specificity 67%, AUC 0.811; P<0.001), 12.7 (sensitivity 96%; specificity 57%; AUC 0.785; P<0.001) and 15.8 (sensitivity 88%; specificity 70%; AUC 0.793; P<0.001). Multivariate analyses indicated WB3SUVmax was independently associated with PFS (hazard ratio [HR]=3.67, 95% confidence interval [95% CI]=1.19, 11.29; P=0.023) and OS (HR= 4.51 [1.02, 19.91]; P=0.047). WB3SUVmax calculated based of the sum of the SUVmax of 3 nodal and 10 extra-nodal lesions was significantly associated with PFS and OS. PMID:27974685
Neutron-transport equation in a general curvelinear coordinate system
Takahashi, H
1981-01-01
Different from a fission reactor, a fusion reactor has complex geometry, such as toroidal geometry. Neutron transport equation for the toroidal coordinate system has been derived by using coordinate transformation from the cartesian coordinate. These methods require rather tedious calculations. Presented here is a simple method to formulate the neutron transport equation in the general curvelinear coordinate system. The equations for parabolic cylinder and toroidal coordinate systems are derived as an example.
Nodal staging of colorectal carcinomas and sentinel nodes
Cserni, G
2003-01-01
This review surveys the staging systems used for the classification of colorectal carcinomas, including the TNM system, and focuses on the assessment of the nodal stage of the disease. It reviews the quantitative requirements for a regional metastatic work up, and some qualitative features of lymph nodes that may help in the selection of positive and negative lymph nodes. Identification of the sentinel lymph nodes (those lymph nodes that have direct drainage from the primary tumour site) is one such qualitative feature that is claimed to allow the upstaging of colorectal carcinomas via an oriented, enhanced pathological work up. Current evidence in favour of a change in the requisite of assessing as may lymph nodes as is possible, and concentrating the efforts on only a selected number of lymph nodes, is weak. PMID:12719450
Contemporary Management of Recurrent Nodal Disease in Differentiated Thyroid Carcinoma
Na’ara, Shorook; Amit, Moran; Fridman, Eran; Gil, Ziv
2016-01-01
Differentiated thyroid carcinoma (DTC) comprises over 90% of thyroid tumors and includes papillary and follicular carcinomas. Patients with DTC have an excellent prognosis, with a 10-year survival rate of over 90%. However, the risk of recurrent tumor ranges between 5% and 30% within 10 years of the initial diagnosis. Cervical lymph node disease accounts for the majority of recurrences and in most cases is detected during follow-up by ultrasound or elevated levels of serum thyroglobulin. Recurrent disease is accompanied by increased morbidity. The mainstay of treatment of nodal recurrence is surgical management. We provide an overview of the literature addressing surgical management of recurrent or persistent lymph node disease in patients with DTC. PMID:26886954
CAISO flicks switch on nodal scheme and lights stay on
2009-06-15
In 2000-01, two years after introducing a competitive wholesale power auction in California - with a separate day-ahead zonal market operated by the California Power Exchange and a zonal market for ancillary services and balancing energy operated by the California Independent System Operator (CAISO) - the California market collapsed from exorbitant prices, flagrant gaming, and abuse of market power. Nine years later, CAISO introduced a nodal pricing auction for the wholesale market in April, replacing the zonal scheme, which was among many causes of the original market's demise. With nearly 3,000 nodes on the network, high prices in one region do not affect prices everywhere on the system. After investing some $200 million to upgrade the software, countless delays, and 18 months of market simulation and testing, the new auction was introduced and nothing unusual happened.
Improving the Accuracy of High-Order Nodal Transport Methods
Azmy, Y.Y.; Buscaglia, G.C.; Zamonsky, O.M.
1999-09-27
This paper outlines some recent advances towards improving the accuracy of neutron transport calculations using the Arbitrarily High Order Transport-Nodal (AHOT-N) Method. These advances consist of several contributions: (a) A formula for the spatial weights that allows for the polynomial order to be raised arbitrarily high without suffering adverse effects from round-off error; (b) A reconstruction technique for the angular flux, based upon a recursive formula, that reduces the pointwise error by one ordeq (c) An a posterior error indicator that estimates the true error and its distribution throughout the domain, so that it can be used for adaptively refining the approximation. Present results are mainly for ID, extension to 2D-3D is in progress.
Improving the Accuracy of High-Order Nodal Transport Methods
Azmy, Y.Y.; Buscaglia, G.C.; Zamonsky, O.M.
1999-09-27
This paper outlines some recent advances towards improving the accuracy of neutron calculations using the Arbitrarily High Order Transport-Nodal (AHOT-N) Method. These transport advances consist of several contributions: (a) A formula for the spatial weights that allows for the polynomial order to be raised arbitrarily high without suffering from pollution from round-off, error; (b) A reconstruction technique for the angular flux, based upon a recursive formula, that reduces the pointwise error by one order; (c) An a posterior error indicator that estimates the true error and its distribution throughout the domain, so that it can be used for adaptively reftig the approximation. Present results are mainly for ID, extension to 2D-3D is in progress.
Magnetic susceptibility in three-dimensional nodal semimetals
NASA Astrophysics Data System (ADS)
Koshino, Mikito; Hizbullah, Intan Fatimah
2016-01-01
We study the magnetic susceptibility in various three-dimensional gapless systems, including Dirac and Weyl semimetals, and a line-node semimetal. The susceptibility is decomposed into the orbital term, the spin term and also the spin-orbit cross term, which is caused by the spin-orbit interaction. We show that the orbital susceptibility logarithmically diverges at the band touching energy in the point-node case, while it exhibits a stronger δ -function singularity in the line node case. The spin-orbit cross term is shown to be paramagnetic in the electron side while diamagnetic in the hole side, in contrast with other two terms which are both even functions in Fermi energy. The spin-orbit cross term in the nodal semimetal is found to be directly related to the chiral surface current induced by the topological surface modes.
Magnetic response in three-dimensional nodal semimetals
NASA Astrophysics Data System (ADS)
Koshino, Mikito; Hizbullah, Intan Fatimah
We study the magnetic response in various three-dimensional gapless systems, including Dirac and Weyl semimetals and a line-node semimetal. We show that the susceptibility is decomposed into the orbital term, the spin term and also the spin-orbit cross term which is caused by the spin-orbit interaction. We show that the orbital susceptibility logarithmically diverges at the band touching energy in the point-node case, while it exhibits a stronger delta-function singularity in the line node case. The spin-orbit cross term is shown to be paramagnetic in the electron side while diamagnetic in the hole side, in contrast with other two terms which are both even functions in Fermi energy. The spin-orbit cross term in the nodal semimetal is found to be directly related to the chiral surface current induced by the topological surface modes.
Nodal domains on isospectral quantum graphs: the resolution of isospectrality?
NASA Astrophysics Data System (ADS)
Band, Ram; Shapira, Talia; Smilansky, Uzy
2006-11-01
We present and discuss isospectral quantum graphs which are not isometric. These graphs are the analogues of the isospectral domains in {\\bb R}^{2} which were introduced recently in Gordon et al (1992 Bull. Am. Math. Soc. 27 134-8), Chapman (1995 Am. Math. Mon. 102 124), Buser et al (1994 Int. Math. Res. Not. 9 391-400), Okada and Shudo (2001 J. Phys. A: Math. Gen. 34 5911-22), Jakobson et al (2006 J. Comput. Appl. Math. 194 141-55) and Levitin et al (2006 J. Phys. A: Math. Gen. 39 2073-82)) all based on Sunada's construction of isospectral domains (Sunada T 1985 Ann. Math. 121 196-86). After presenting some of the properties of these graphs, we discuss a few examples which support the conjecture that by counting the nodal domains of the corresponding eigenfunctions one can resolve the isospectral ambiguity.
Static benchmarking of the NESTLE advanced nodal code
Mosteller, R.D.
1997-05-01
Results from the NESTLE advanced nodal code are presented for multidimensional numerical benchmarks representing four different types of reactors, and predictions from NESTLE are compared with measured data from pressurized water reactors (PWRs). The numerical benchmarks include cases representative of PWRs, boiling water reactors (BWRs), CANDU heavy water reactors (HWRs), and high-temperature gas-cooled reactors (HTGRs). The measured PWR data include critical soluble boron concentrations and isothermal temperature coefficients of reactivity. The results demonstrate that NESTLE correctly solves the multigroup diffusion equations for both Cartesian and hexagonal geometries, that it reliably calculates k{sub eff} and reactivity coefficients for PWRs, and that--subsequent to the incorporation of additional thermal-hydraulic models--it will be able to perform accurate calculations for the corresponding parameters in BWRs, HWRs, and HTGRs as well.
On-line application of the PANTHER advanced nodal code
Hutt, P.K.; Knight, M.P. )
1992-01-01
Over the last few years, Nuclear Electric has developed an integrated core performance code package for both light water reactors (LWRs) and advanced gas-cooled reactors (AGRs) that can perform a comprehensive range of calculations for fuel cycle design, safety analysis, and on-line operational support for such plants. The package consists of the following codes: WIMS for lattice physics, PANTHER whole reactor nodal flux and AGR thermal hydraulics, VIPRE for LWR thermal hydraulics, and ENIGMA for fuel performance. These codes are integrated within a UNIX-based interactive system called the Reactor Physics Workbench (RPW), which provides an interactive graphic user interface and quality assurance records/data management. The RPW can also control calculational sequences and data flows. The package has been designed to run both off-line and on-line accessing plant data through the RPW.
ProNodal acts via FGFR3 to govern duration of Shh expression in the prechordal mesoderm
Ellis, Pamela S.; Burbridge, Sarah; Soubes, Sandrine; Ohyama, Kyoji; Ben-Haim, Nadav; Chen, Canhe; Dale, Kim; Shen, Michael M.; Constam, Daniel; Placzek, Marysia
2015-01-01
The secreted glycoprotein sonic hedgehog (Shh) is expressed in the prechordal mesoderm, where it plays a crucial role in induction and patterning of the ventral forebrain. Currently little is known about how Shh is regulated in prechordal tissue. Here we show that in the embryonic chick, Shh is expressed transiently in prechordal mesoderm, and is governed by unprocessed Nodal. Exposure of prechordal mesoderm microcultures to Nodal-conditioned medium, the Nodal inhibitor CerS, or to an ALK4/5/7 inhibitor reveals that Nodal is required to maintain both Shh and Gsc expression, but whereas Gsc is largely maintained through canonical signalling, Nodal signals through a non-canonical route to maintain Shh. Further, Shh expression can be maintained by a recombinant Nodal cleavage mutant, proNodal, but not by purified mature Nodal. A number of lines of evidence suggest that proNodal acts via FGFR3. ProNodal and FGFR3 co-immunoprecipitate and proNodal increases FGFR3 tyrosine phosphorylation. In microcultures, soluble FGFR3 abolishes Shh without affecting Gsc expression. Further, prechordal mesoderm cells in which Fgfr3 expression is reduced by Fgfr3 siRNA fail to bind to proNodal. Finally, targeted electroporation of Fgfr3 siRNA to prechordal mesoderm in vivo results in premature Shh downregulation without affecting Gsc. We report an inverse correlation between proNodal-FGFR3 signalling and pSmad1/5/8, and show that proNodal-FGFR3 signalling antagonises BMP-mediated pSmad1/5/8 signalling, which is poised to downregulate Shh. Our studies suggest that proNodal/FGFR3 signalling governs Shh duration by repressing canonical BMP signalling, and that local BMPs rapidly silence Shh once endogenous Nodal-FGFR3 signalling is downregulated. PMID:26417042
An boldsymbol{E} -based mixed formulation for a time-dependent eddy current problem
NASA Astrophysics Data System (ADS)
Acevedo, Ramiro; Meddahi, Salim; Rodriguez, Rodolfo
2009-12-01
In this paper, we analyze a mixed form of a time-dependent eddy current problem formulated in terms of the electric field boldsymbol{E} . We show that this formulation admits a well-posed saddle point structure when the constraints satisfied by the primary unknown in the dielectric material are handled by means of a Lagrange multiplier. We use Nedelec edge elements and standard nodal finite elements to define a semi-discrete Galerkin scheme. Furthermore, we introduce the corresponding backward-Euler fully-discrete formulation and prove error estimates.
Stable and flux-conserved meshfree formulation to model shocks
NASA Astrophysics Data System (ADS)
Roth, Michael J.; Chen, Jiun-Shyan; Slawson, Thomas R.; Danielson, Kent T.
2016-05-01
Accurate shock modeling requires that two critical issues be addressed: (1) correct representation of the essential shock physics, and (2) control of Gibbs phenomenon oscillation at the discontinuity. In this work a stable (oscillation limiting) and flux-conserved formulation under the reproducing kernel particle method is developed for shock modeling. A smoothed flux divergence is constructed under the framework of stabilized conforming nodal integration, which is locally-enriched with a Riemann solution to satisfy the entropy production constraints. This Riemann-enriched flux divergence is embedded into the reproducing kernel formulation through a velocity correction that also provides oscillation control at the shock. The correction is constrained to the shock region by an automatic shock detection algorithm that is constructed using the intrinsic spectral decomposition feature of the reproducing kernel approximation. Several numerical examples are provided to verify accuracy of the proposed formulation.
Covariant Formulations of Superstring Theories.
NASA Astrophysics Data System (ADS)
Mikovic, Aleksandar Radomir
1990-01-01
Chapter 1 contains a brief introduction to the subject of string theory, and tries to motivate the study of superstrings and covariant formulations. Chapter 2 describes the Green-Schwarz formulation of the superstrings. The Hamiltonian and BRST structure of the theory is analysed in the case of the superparticle. Implications for the superstring case are discussed. Chapter 3 describes the Siegel's formulation of the superstring, which contains only the first class constraints. It is shown that the physical spectrum coincides with that of the Green-Schwarz formulation. In chapter 4 we analyse the BRST structure of the Siegel's formulation. We show that the BRST charge has the wrong cohomology, and propose a modification, called first ilk, which gives the right cohomology. We also propose another superparticle model, called second ilk, which has infinitely many coordinates and constraints. We construct the complete BRST charge for it, and show that it gives the correct cohomology. In chapter 5 we analyse the properties of the covariant vertex operators and the corresponding S-matrix elements by using the Siegel's formulation. We conclude that the knowledge of the ghosts is necessary, even at the tree level, in order to obtain the correct S-matrix. In chapter 6 we attempt to calculate the superstring loops, in a covariant gauge. We calculate the vacuum-to -vacuum amplitude, which is also the cosmological constant. We show that it vanishes to all loop orders, under the assumption that the free covariant gauge-fixed action exists. In chapter 7 we present our conclusions, and briefly discuss the random lattice approach to the string theory, as a possible way of resolving the problem of the covariant quantization and the nonperturbative definition of the superstrings.
Lawrence, Mitchell G.; Margaryan, Naira V.; Loessner, Daniela; Collins, Angus; Kerr, Kris M.; Turner, Megan; Seftor, Elisabeth A.; Stephens, Carson R.; Lai, John; BioResource, APC; Postovit, Lynne-Marie; Clements, Judith A.; Hendrix, Mary J.C.
2011-01-01
Background Nodal is a member of the Transforming Growth Factor β (TGFβ) superfamily that directs embryonic patterning and promotes the plasticity and tumorigenicity of tumor cells, but its role in the prostate is unknown. The goal of this study was to characterize the expression and function of Nodal in prostate cancer and determine whether, like other TGFβ ligands, it modulates androgen receptor (AR) activity. Methods Nodal expression was investigated using immunohistochemistry of tissue microarrays and Western blots of prostate cell lines. The functional role of Nodal was examined using Matrigel and soft agar growth assays. Cross-talk between Nodal and AR signaling was assessed with luciferase reporter assays and expression of endogenous androgen regulated genes. Results Significantly increased Nodal expression was observed in cancer compared with benign prostate specimens. Nodal was only expressed by DU145 and PC3 cells. All cell lines expressed Nodal’s co-receptor, Cripto-1, but lacked Lefty, a critical negative regulator of Nodal signaling. Recombinant human Nodal triggered downstream Smad2 phosphorylation in DU145 and LNCaP cells, and stable transfection of pre-pro-Nodal enhanced the growth of LNCaP cells in Matrigel and soft agar. Finally, Nodal attenuated AR signaling, reducing the activity of a PSA promoter construct in luciferase assays and down-regulating the endogenous expression of androgen regulated genes. Conclusions An aberrant Nodal signaling pathway is re-expressed and functionally active in prostate cancer cells. PMID:21656830
Liu, Xiuli; Ma, Yuanqing; Zhang, Congwei; Wei, Shi; Cao, Yu; Wang, Qiang
2013-10-20
Nodal, a member of the transforming growth factor β (TGF-β) superfamily, has been shown to play a role in mesendoderm induction and gastrulation movements. The activity of Nodal signaling can be modulated by microRNAs (miRNAs) as previously reported, but little is known about which miRNAs are regulated by Nodal during gastrulation. In the present study, we found that the expression of mir206, one of the most abundant miRNAs during zebrafish early embryo development, is regulated by Nodal signaling. Abrogation of Nodal signal activity results in defective convergence and extension (CE) movements, and these cell migration defects can be rescued by supplying an excess of mir206, suggesting that mir206 acts downstream of Nodal signaling to regulate CE movements. Furthermore, in mir206 morphants, the expression of cell adhesion molecule E-cadherin is significantly increased, while the key transcriptional repressor of E-cadherin, snail1a, is depressed. Our study uncovers a novel mechanism by which Nodal-regulated mir206 modulates gastrulation movements in connection with the Snail/E-cadherin pathway.
Xantivin suppresses the activity of EGF-CFC genes to regulate nodal signaling.
Tanegashima, Kousuke; Haramoto, Yoshikazu; Yokota, Chika; Takahashi, Shuji; Asashima, Makoto
2004-06-01
Lefty, antivin and related genes act in a feedback inhibition mechanism for nodal signaling at a number of stages of vertebrate embryogenesis. To analyze the function of the feedback inhibitor of nodal signaling, Xantivin in Xenopus embryos, we designed a morpholino antisense oligonucleotide (XatvMO) for this gene. XatvMO caused the expansion of mesodermal tissue and head defects. XatvMO-injected gastrulae showed up-regulated expression of the mesodermal markers Xbra, Xwnt8, Xnot, and Chordin, suggesting expansion of the trunk-tail organizer. As expected, depletion of Xantivin also up-regulated nodal signaling as confirmed by the enhanced ectopic expression of Xantivin mRNA, a known target gene of nodal signaling. Furthermore, we investigated the relationship between Xantivin and the EGF-CFC gene FRL-1, which is a component of the nodal receptor. In animal cap assays, FRL-1 could not induce expression of nodal-responsive genes, but could up-regulate expression of these genes when FRL-1 was coinjected with a low dose of Xnr1; coinjection of Xantivin suppressed this up-regulation by FRL-1. We also found that Xantivin can rescue the caudalized phenotype induced by overexpression of FRL-1. Co-immunoprecipitation assays showed that Xantivin interacted with the EGF-CFC proteins, FRL-1 and cripto. Taken together, these results suggest that Xantivin opposes the activity of EGF-CFC genes and thereby antagonizes nodal signaling.
McAllister, Josephine C; Zhan, Qian; Weishaupt, Carsten; Hsu, Mei-Yu; Murphy, George F
2010-04-01
Formation of channel-like structures, also termed vasculogenic mimicry (VM), describes the ability of aggressive melanoma cells to form PAS-positive anastomosing structures that correlate with tumor virulence. This phenomenon may indicate differentiation plasticity, a feature melanoma cells may share with stem cells in the developing embryo. Recent studies have indicated that VM and tumorigenicity of human malignant melanoma may depend on the signaling pathways of an embryonic morphogen, Nodal. However, given the secretory nature of Nodal protein and melanoma cell heterogeneity, it remains unclear whether the Nodal-expressing cells participate directly or indirectly in VM that is potentially related to tumorigenic growth. We have developed a humanized murine xenograft model in which developing human melanomas may be sequentially studied during early stages of tumorigenic growth within a physiological human dermal microenvironment. Nodal protein localized diffusely to melanoma cell membranes, with occasional foci of accentuated reactivity in patterns suggestive of channel formation. Similar findings were detected in a limited number of patient-derived tumors. In situ hybridization confirmed Nodal mRNA to be restricted to tumor cells within xenografts that formed arborizing networks in patterns consistent with VM. These data indicate that Nodal gene expression is associated with formation of VM-like structures in a physiologically relevant model of human melanoma tumorigenesis, and further support a key role for Nodal expression in the formation of channel-like structures. The humanized xenograft model should be useful in future studies to define the mechanistic pathways responsible for VM and melanoma progression.
Nodal signals mediate interactions between the extra-embryonic and embryonic tissues in zebrafish.
Fan, Xiang; Hagos, Engda G; Xu, Bo; Sias, Christina; Kawakami, Koichi; Burdine, Rebecca D; Dougan, Scott T
2007-10-15
In many vertebrates, extra-embryonic tissues are important signaling centers that induce and pattern the germ layers. In teleosts, the mechanism by which the extra-embryonic yolk syncytial layer (YSL) patterns the embryo is not understood. Although the Nodal-related protein Squint is expressed in the YSL, its role in this tissue is not known. We generated a series of stable transgenic lines with GFP under the control of squint genomic sequences. In all species, nodal-related genes induce their own expression through a positive feedback loop. We show that two tissue specific enhancers in the zebrafish squint gene mediate the response to Nodal signals. Expression in the blastomeres depends upon a conserved Nodal response element (NRE) in the squint first intron, while expression in the extra-embryonic enveloping layer (EVL) is mediated by an element upstream of the transcription start site. Targeted depletion experiments demonstrate that the zebrafish Nodal-related proteins Squint and Cyclops are required in the YSL for endoderm and head mesoderm formation. Thus, Nodal signals mediate interactions between embryonic and extra-embryonic tissues in zebrafish that maintain nodal-related gene expression in the margin. Our results demonstrate a high degree of functional conservation between the extra-embryonic tissues of mouse and zebrafish.
Nicalin and its binding partner Nomo are novel Nodal signaling antagonists.
Haffner, Christof; Frauli, Mélanie; Topp, Stephanie; Irmler, Martin; Hofmann, Kay; Regula, Jörg T; Bally-Cuif, Laure; Haass, Christian
2004-08-04
Nodals are signaling factors of the transforming growth factor-beta (TGFbeta) superfamily with a key role in vertebrate development. They control a variety of cell fate decisions required for the establishment of the embryonic body plan. We have identified two highly conserved transmembrane proteins, Nicalin and Nomo (Nodal modulator, previously known as pM5), as novel antagonists of Nodal signaling. Nicalin is distantly related to Nicastrin, a component of the Alzheimer's disease-associated gamma-secretase, and forms a complex with Nomo. Ectopic expression of both proteins in zebrafish embryos causes cyclopia, a phenotype that can arise from a defect in mesendoderm patterning mediated by the Nodal signaling pathway. Accordingly, downregulation of Nomo resulted in an increase in anterior axial mesendoderm and the development of an enlarged hatching gland. Inhibition of Nodal signaling by ectopic expression of Lefty was rescued by reducing Nomo levels. Furthermore, Nodal- as well as Activin-induced signaling was inhibited by Nicalin and Nomo in a cell-based reporter assay. Our data demonstrate that the Nicalin/Nomo complex antagonizes Nodal signaling during mesendodermal patterning in zebrafish.
Nicalin and its binding partner Nomo are novel Nodal signaling antagonists
Haffner, Christof; Frauli, Mélanie; Topp, Stephanie; Irmler, Martin; Hofmann, Kay; Regula, Jörg T; Bally-Cuif, Laure; Haass, Christian
2004-01-01
Nodals are signaling factors of the transforming growth factor-β (TGFβ) superfamily with a key role in vertebrate development. They control a variety of cell fate decisions required for the establishment of the embryonic body plan. We have identified two highly conserved transmembrane proteins, Nicalin and Nomo (Nodal modulator, previously known as pM5), as novel antagonists of Nodal signaling. Nicalin is distantly related to Nicastrin, a component of the Alzheimer's disease-associated γ-secretase, and forms a complex with Nomo. Ectopic expression of both proteins in zebrafish embryos causes cyclopia, a phenotype that can arise from a defect in mesendoderm patterning mediated by the Nodal signaling pathway. Accordingly, downregulation of Nomo resulted in an increase in anterior axial mesendoderm and the development of an enlarged hatching gland. Inhibition of Nodal signaling by ectopic expression of Lefty was rescued by reducing Nomo levels. Furthermore, Nodal- as well as Activin-induced signaling was inhibited by Nicalin and Nomo in a cell-based reporter assay. Our data demonstrate that the Nicalin/Nomo complex antagonizes Nodal signaling during mesendodermal patterning in zebrafish. PMID:15257293
NASA Astrophysics Data System (ADS)
Cohen, R. J.
2004-06-01
The Radio Regulations set out complex procedures to ensure that when new systems start to use the frequency bands allocated to them there is minimal disruption to existing systems using the same bands. The process of satellite coordination is described, and the issues for radio astronomy are discussed. In order to be protected by the ITU-R machinery radio telescopes need to be officially registered. The issue of paper satellites highlights the need for early registration to gain priority over incoming systems. Modern developments including the use of complex Monte-Carlo simulations to predict interference levels, and the issue of adjacent band interference, are discussed.
Nodal signaling is required for closure of the anterior neural tube in zebrafish
Aquilina-Beck, Allisan; Ilagan, Kristine; Liu, Qin; Liang, Jennifer O
2007-01-01
Background Nodals are secreted signaling proteins with many roles in vertebrate development. Here, we identify a new role for Nodal signaling in regulating closure of the rostral neural tube of zebrafish. Results We find that the neural tube in the presumptive forebrain fails to close in zebrafish Nodal signaling mutants. For instance, the cells that will give rise to the pineal organ fail to move from the lateral edges of the neural plate to the midline of the diencephalon. The open neural tube in Nodal signaling mutants may be due in part to reduced function of N-cadherin, a cell adhesion molecule expressed in the neural tube and required for neural tube closure. N-cadherin expression and localization to the membrane are reduced in fish that lack Nodal signaling. Further, N-cadherin mutants and morphants have a pineal phenotype similar to that of mutants with deficiencies in the Nodal pathway. Overexpression of an activated form of the TGFβ Type I receptor Taram-A (Taram-A*) cell autonomously rescues mesendoderm formation in fish with a severe decrease in Nodal signaling. We find that overexpression of Taram-A* also corrects their open neural tube defect. This suggests that, as in mammals, the mesoderm and endoderm have an important role in regulating closure of the anterior neural tube of zebrafish. Conclusion This work helps establish a role for Nodal signals in neurulation, and suggests that defects in Nodal signaling could underlie human neural tube defects such as exencephaly, a fatal condition characterized by an open neural tube in the anterior brain. PMID:17996054
Mohapatra, Bhagyalaxmi; Casey, Brett; Li, Hua; Ho-Dawson, Trang; Smith, Liana; Fernbach, Susan D.; Molinari, Laura; Niesh, Stephen R.; Jefferies, John Lynn; Craigen, William J.; Towbin, Jeffrey A.; Belmont, John W.; Ware, Stephanie M.
2009-01-01
NODAL and its signaling pathway are known to play a key role in specification and patterning of vertebrate embryos. Mutations in several genes encoding components of the NODAL signaling pathway have previously been implicated in the pathogenesis of human left–right (LR) patterning defects. Therefore, NODAL, a member of TGF-β superfamily of developmental regulators, is a strong candidate to be functionally involved in congenital LR axis patterning defects or heterotaxy. Here we have investigated whether variants in NODAL are present in patients with heterotaxy and/or isolated cardiovascular malformations (CVM) thought to be caused by abnormal heart tube looping. Analysis of a large cohort of cases (n = 269) affected with either classic heterotaxy or looping CVM revealed four different missense variants, one in-frame insertion/deletion and two conserved splice site variants in 14 unrelated subjects (14/269, 5.2%). Although similar with regard to other associated defects, individuals with the NODAL mutations had a significantly higher occurrence of pulmonary valve atresia (P = 0.001) compared with cases without a detectable NODAL mutation. Functional analyses demonstrate that the missense variant forms of NODAL exhibit significant impairment of signaling as measured by decreased Cripto (TDGF-1) co-receptor-mediated activation of artificial reporters. Expression of these NODAL proteins also led to reduced induction of Smad2 phosphorylation and impaired Smad2 nuclear import. Taken together, these results support a role for mutations and rare deleterious variants in NODAL as a cause for sporadic human LR patterning defects. PMID:19064609
Calvanese, Luisa; Sandomenico, Annamaria; Caporale, Andrea; Focà, Annalia; Focà, Giuseppina; D'Auria, Gabriella; Falcigno, Lucia; Ruvo, Menotti
2015-04-01
Nodal, a member of the TGF-β superfamily, is a potent embryonic morphogen also implicated in tumor progression. As for other TGF-βs, it triggers the signaling functions through the interaction with the extracellular domains of type I and type II serine/threonine kinase receptors and with the co-receptor Cripto. Recently, we reported the molecular models of Nodal in complex with its type I receptors (ALK4 and ALK7) as well as with Cripto, as obtained by homology modeling and docking simulations. From such models, potential binding epitopes have been identified. To validate such hypotheses, a series of mutated Nodal fragments have been synthesized. These peptide analogs encompass residues 44-67 of the Nodal protein, corresponding to the pre-helix loop and the H3 helix, and reproduce the wild-type sequence or bear some modifications to evaluate the hot-spot role of modified residues in the receptor binding. Here, we show the structural characterization in solution by CD and NMR of the Nodal peptides and the measurement of binding affinity toward Cripto by surface plasmon resonance. Data collected by both conformational analyses and binding measurements suggest a role for Y58 of Nodal in the recognition with Cripto and confirm that previously reported for E49 and E50. Surface plasmon resonance binding assays with recombinant proteins show that Nodal interacts in vitro also with ALK7 and ALK4 and preliminary data, generated using the Nodal synthetic fragments, suggest that Y58 of Nodal may also be involved in the recognition with these protein partners.
Cerberus-Nodal-Lefty-Pitx signaling cascade controls left-right asymmetry in amphioxus.
Li, Guang; Liu, Xian; Xing, Chaofan; Zhang, Huayang; Shimeld, Sebastian M; Wang, Yiquan
2017-04-04
Many bilaterally symmetrical animals develop genetically programmed left-right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left-right asymmetry as a larva. We show that Cerberus, Nodal, Lefty, and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal, Lefty, and Pitx, whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal, whereas Pitx activates Nodal These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left-right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left-right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.
Simulation of turbulent flows using nodal integral method
NASA Astrophysics Data System (ADS)
Singh, Suneet
Nodal methods are the backbone of the production codes for neutron-diffusion and transport equations. Despite their high accuracy, use of these methods for simulation of fluid flow is relatively new. Recently, a modified nodal integral method (MNIM) has been developed for simulation of laminar flows. In view of its high accuracy and efficiency, extension of this method for the simulation of turbulent flows is a logical step forward. In this dissertation, MNIM is extended in two ways to simulate incompressible turbulent flows---a new MNIM is developed for the 2D k-epsilon equations; and 3D, parallel MNIM is developed for direct numerical simulations. Both developments are validated, and test problems are solved. In this dissertation, a new nodal numerical scheme is developed to solve the k-epsilon equations to simulate turbulent flows. The MNIM developed earlier for laminar flow equations is modified to incorporate eddy viscosity approximation and coupled with the above mentioned schemes for the k and epsilon equations, to complete the implementation of the numerical scheme for the k-epsilon model. The scheme developed is validated by comparing the results obtained by the developed method with the results available in the literature obtained using direct numerical simulations (DNS). The results of current simulations match reasonably well with the DNS results. The discrepancies in the results are mainly due to the limitations of the k-epsilon model rather than the deficiency in the developed MNIM. A parallel version of the MNIM is needed to enhance its capability, in order to carry out DNS of the turbulent flows. The parallelization of the scheme, however, presents some unique challenges as dependencies of the discrete variables are different from those that exist in other schemes (for example in finite volume based schemes). Hence, a parallel MNIM (PMNIM) is developed and implemented into a computer code with communication strategies based on the above mentioned
Detection of 18.6 year nodal induced drought in the Patagonian Andes
NASA Astrophysics Data System (ADS)
Currie, Robert G.
1983-11-01
Analysis of tree-ring chronologies from the Patagonian Andes yields evidence for the 18.6 yr lunar nodal term in drought/flood. The mean discrepancy between epochs of drought/flood and the nodal tide since AD 1600 is 0.7 ± 2.2 yr, but the polarity of the signal is apparently bimodal. From nodal epoch 1750.0 through 1898.9 drought and tide were in phase, whereas prior to 1750.0 and subsequent to 1898.9 drought and tide were out of phase. There is evidence also for the solar cycle drought signal in the data.
[Method for optimal sensor placement in water distribution systems with nodal demand uncertainties].
Liu, Shu-Ming; Wu, Xue; Ouyang, Le-Yan
2013-08-01
The notion of identification fitness was proposed for optimizing sensor placement in water distribution systems. Nondominated Sorting Genetic Algorithm II was used to find the Pareto front between minimum overlap of possible detection times of two events and the best probability of detection, taking nodal demand uncertainties into account. This methodology was applied to an example network. The solutions show that the probability of detection and the number of possible locations are not remarkably affected by nodal demand uncertainties, but the sources identification accuracy declines with nodal demand uncertainties.
On the inverse nodal problems for discontinuous Sturm-Liouville operators
NASA Astrophysics Data System (ADS)
Wang, Yu Ping; Yurko, V. A.
2016-03-01
In this paper, we discuss the inverse nodal problems for discontinuous Sturm-Liouville operators with Robin boundary conditions. We show that the potential q up to its mean value on the interval [ 0 , 1 ] and coefficients h, H, b/a can be uniquely determined by the twin-dense nodal subset on the subinterval [a0 ,b0 ], a0 <1/2
Micropropagation of Calophyllum brasiliense (Cambess.) from nodal segments.
Silveira, S S; Cordeiro-Silva, R; Degenhardt-Goldbach, J; Quoirin, M
2016-05-03
Micropropagation of Calophyllum brasiliense Cambess. (Clusiaceae) is a way to overcome difficulties in achieving large-scale plant production, given the recalcitrant nature of the seeds, irregular fructification and absence of natural vegetative propagation of the species. Cultures were established using nodal segments 2 cm in length, obtained from 1-2 year old seedlings, maintained in a greenhouse. Mercury chloride and Plant Preservative Mixture™ were used in the surface sterilizing stage, better results being achieved with Plant Preservative Mixture™ incorporation in culture medium, at any concentration. Polyvinylpyrrolidone, activated charcoal, cysteine, ascorbic acid or citric acid were added to the culture medium to avoid oxidation. After 30 days of culture, polyvinylpirrolidone and ascorbic acid gave better results, eliminating oxidation in most explants. For shoot multiplication, benzylaminopurine was used in concentrations of 4.4 and 8.8 µM in Woody Plant Medium, resulting in an average of 4.43 and 4.68 shoots per explant, respectively, after 90 days. Indole-3-butyric acid and α-naphthalene acetic acid were used to induce root formation, reaching a maximum rooting rate of 24% with 20µM α-naphthalene acetic acid. For acclimatization. the rooted plants were transferred to Plantmax® substrate and cultured in a greenhouse, reaching 79% of survival after 30 days and 60% after one year.
Micropropagation of commercially cultivated Henna (Lawsonia inermis) using nodal explants.
Ram, Kheta; Shekhawat, N S
2011-07-01
Lawsonia inermis Linn. (Mehandi) is cultivated as cash crop in India particularly in Sojat area of Pali district, Rajasthan. Present investigation describes an efficient regeneration system for elite genotype of L. inermis using nodal segments. Optimum response in terms of percent cultures responding, days to bud break and average shoot length was observed on MS medium supplemented with 6-benzylaminopurine (BA; 2.0 mg l(-1)). Shoot multiplication was influenced by plant growth regulators, repeated transfer of explants and addition of ammonium sulphate. Maximum shoots were regenerated on MS medium supplemented with BA (0.25 mg l(-1)), kinetin (Kn; 0.25 mg l(-1)), indole-3-acetic acid (IAA; 0.1 mg l(-1)) and ammonium sulphate (150 mg l(-1)). To reduce resources, time and labours costs, we have also attempted ex vitro rooting of shoots. About 95 % shoots were rooted ex vitro on soilrite after treatment with indole-3-butyric acid (IBA; 300 mg l(-1)) and 2-naphthoxy acetic acid (NOA; 100 mg l(-1)) and establishment in soil successfully.
Peters, Arne
2016-01-01
The enduring stages of entomopathogenic nematodes of the genera Steinernema and Heterorhabditis are infective juveniles, which require a high humidity and sufficient ventilation for survival. Formulations must account for these requirements. Nematodes may be formulated inside the insects in which they reproduced or they need to be cleaned and mixed with a suitable binder to maintain humidity but allowing for gas exchange. Another method for formulation is the encapsulation in beads of Ca-alginate. Generic procedures for these formulation techniques are described.
Dose-dependent Nodal/Smad signals pattern the early mouse embryo.
Robertson, Elizabeth J
2014-08-01
Nodal signals in the early post-implantation stage embryo are essential to establish initial proximal-distal (P-D) polarity and generate the final anterior-posterior (A-P) body axis. Nodal signaling in the epiblast results in the phosphorylation of Smad2 in the overlying visceral endoderm necessary to induce the AVE, in part via Smad2-dependent activation of the T-box gene Eomesodermin. Slightly later following mesoderm induction a continuum of dose-dependent Nodal signaling during the process of gastrulation underlies specification of mesodermal and definitive endoderm progenitors. Dynamic Nodal expression during the critical 72 h time window immediately following implantation, accomplished by a series of feed-back and feed-forward mechanisms serves to provide key positional cues required for establishment of the body plan and controls cell fate decisions in the early mammalian embryo.
Nodal Domain Statistics for Quantum Maps, Percolation, and Stochastic Loewner Evolution
Keating, J. P.; Marklof, J.; Williams, I. G.
2006-07-21
We develop a percolation model for nodal domains in the eigenvectors of quantum chaotic torus maps. Our model follows directly from the assumption that the quantum maps are described by random matrix theory. Its accuracy in predicting statistical properties of the nodal domains is demonstrated for perturbed cat maps and supports the use of percolation theory to describe the wave functions of general Hamiltonian systems. We also demonstrate that the nodal domains of the perturbed cat maps obey the Cardy crossing formula and find evidence that the boundaries of the nodal domains are described by stochastic Loewner evolution with diffusion constant {kappa} close to the expected value of 6, suggesting that quantum chaotic wave functions may exhibit conformal invariance in the semiclassical limit.
Relation between finite element methods and nodal methods in transport theory
Walters, W.F.
1985-01-01
This paper examines the relationship between nodal methods and finite-element methods for solving the discrete-ordinates form of the transport equation in x-y geometry. Specifically, we will examine the relation of three finite-element schemes to the linear-linear (LL) and linear-nodal (LN) nodal schemes. The three finite-element schemes are the linear-continuous-diamond-difference (DD) scheme, the linear-discontinuous (LD) scheme, and the quadratic-discontinuous (QD) scheme. A brief derivation of the (LL) and (LN) nodal schemes is given in the third section of this paper. The approximations that cause the LL scheme to reduce to the DD, LD, and QD schemes are then indicated. An extremely simple method of deriving the finite-element schemes is then introduced.
The Application of Modern Nodal Methods to Pwr Reactor Physics Analysis.
NASA Astrophysics Data System (ADS)
Knight, M. P.
Available from UMI in association with The British Library. The objective of this research is to develop efficient computational procedures for PWR reactor calculations, based on modern nodal methods. The analytic nodal method, which is characterised by the use of exact exponential expansions in transverse-integrated equations, is implemented within an existing finite-difference code. This shows considerable accuracy and efficiency on standard benchmark problems, very much in line with existing experience with nodal methods. Assembly powers can be calculated to within 2.0% with just one mesh per assembly. The recovery of fine detail from a nodal solution based on such a coarse mesh requires additional effort. Techniques are develolped in this thesis which allow the basic nodal equations to be used in this reconstruction, and therefore provide a consistent approach. Pin powers can be recovered from assembly-averaged values with little further loss of accuracy. A similar investigation is followed with the transverse leakage distribution. An improvement, which uses known local behaviour, is shown to be very effective in some limited applications, but overall provides little advantage over the much simpler quadratic model. For heterogeneous calculations it is essential that the homogenisation techniques are well matched to the nodal method. The asymmetric design of some assemblies provides a severe test. Techniques are devised that allow some overall representation of this asymmetry to be retained in the reactor calculation, even when using one mesh per assembly. Extensions of this procedure provide an almost exact global representation of a heterogeneous assembly. A complete comparison is performed between reactor calculations at one mesh per pin, and at one mesh per assembly using nodal and homogenisation methods. Homogenisation errors and nodal coarse-mesh errors are shown to be very similar, amounting to about 0.1% on reactor eigenvalue, 2.0% on assembly power and
Trichas, Georgios; Wilkins, Vivienne; Clements, Melanie; Tada, Masazumi; Rodriguez, Tristan A.; Srinivas, Shankar
2011-01-01
The anterior visceral endoderm (AVE), a signalling centre within the simple epithelium of the visceral endoderm (VE), is required for anterior-posterior axis specification in the mouse embryo. AVE cells migrate directionally within the VE, thereby properly positioning the future anterior of the embryo and orientating the primary body axis. AVE cells consistently come to an abrupt stop at the border between the anterior epiblast and extra-embryonic ectoderm, which represents an end-point to their proximal migration. Little is known about the underlying basis for this barrier and how surrounding cells in the VE respond to or influence AVE migration. We use high-resolution 3D reconstructions of protein localisation patterns and time-lapse microscopy to show that AVE cells move by exchanging neighbours within an intact epithelium. Cell movement and mixing is restricted to the VE overlying the epiblast, characterised by the enrichment of Dishevelled-2 (Dvl2) to the lateral plasma membrane, a hallmark of Planar Cell Polarity (PCP) signalling. AVE cells halt upon reaching the adjoining region of VE overlying the extra-embryonic ectoderm, which displays reduced neighbour exchange and in which Dvl2 is excluded specifically from the plasma membrane. Though a single continuous sheet, these two regions of VE show distinct patterns of F-actin localisation, in cortical rings and an apical shroud, respectively. We genetically perturb PCP signalling and show that this disrupts the localisation pattern of Dvl2 and F-actin and the normal migration of AVE cells. In Nodal null embryos, membrane localisation of Dvl2 is reduced, while in mutants for the Nodal inhibitor Lefty1, Dvl2 is ectopically membrane localised, establishing a role for Nodal in modulating PCP signalling. These results show that the limits of AVE migration are determined by regional differences in cell behaviour and protein localisation within an otherwise apparently uniform VE. In addition to coordinating global
A quasi-static polynomial nodal method for nuclear reactor analysis
Gehin, J.C.
1992-09-01
Modern nodal methods are currently available which can accurately and efficiently solve the static and transient neutron diffusion equations. Most of the methods, however, are limited to two energy groups for practical application. The objective of this research is the development of a static and transient, multidimensional nodal method which allows more than two energy groups and uses a non-linear iterative method for efficient solution of the nodal equations. For both the static and transient methods, finite-difference equations which are corrected by the use of discontinuity factors are derived. The discontinuity factors are computed from a polynomial nodal method using a non-linear iteration technique. The polynomial nodal method is based upon a quartic approximation and utilizes a quadratic transverse-leakage approximation. The solution of the time-dependent equations is performed by the use of a quasi-static method in which the node-averaged fluxes are factored into shape and amplitude functions. The application of the quasi-static polynomial method to several benchmark problems demonstrates that the accuracy is consistent with that of other nodal methods. The use of the quasi-static method is shown to substantially reduce the computation time over the traditional fully-implicit time-integration method. Problems involving thermal-hydraulic feedback are accurately, and efficiently, solved by performing several reactivity/thermal-hydraulic updates per shape calculation.
Topological Dirac nodal lines and surface charges in fcc alkaline earth metals
Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi; Murakami, Shuichi
2017-01-01
In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin–orbit interaction is neglected. In particular, Ca becomes a nodal-line semimetal at high pressure. Owing to nodal lines, the Zak phase becomes either π or 0, depending on the wavevector k, and the π Zak phase leads to surface polarization charge. Carriers eventually screen it, leaving behind large surface dipoles. In materials with nodal lines, both the large surface polarization charge and the emergent drumhead surface states enhance Rashba splitting when heavy adatoms are present, as we have shown to occur in Bi/Sr(111) and in Bi/Ag(111). PMID:28074835
Dmitriy Y. Anistratov; Marvin L. Adams; Todd S. Palmer; Kord S. Smith; Kevin Clarno; Hikaru Hiruta; Razvan Nes
2003-08-04
OAK (B204) Final Report, NERI Project: ''An Innovative Reactor Analysis Methodology Based on a Quasidiffusion Nodal Core Model'' The present generation of reactor analysis methods uses few-group nodal diffusion approximations to calculate full-core eigenvalues and power distributions. The cross sections, diffusion coefficients, and discontinuity factors (collectively called ''group constants'') in the nodal diffusion equations are parameterized as functions of many variables, ranging from the obvious (temperature, boron concentration, etc.) to the more obscure (spectral index, moderator temperature history, etc.). These group constants, and their variations as functions of the many variables, are calculated by assembly-level transport codes. The current methodology has two main weaknesses that this project addressed. The first weakness is the diffusion approximation in the full-core calculation; this can be significantly inaccurate at interfaces between different assemblies. This project used the nodal diffusion framework to implement nodal quasidiffusion equations, which can capture transport effects to an arbitrary degree of accuracy. The second weakness is in the parameterization of the group constants; current models do not always perform well, especially at interfaces between unlike assemblies. The project developed a theoretical foundation for parameterization and homogenization models and used that theory to devise improved models. The new models were extended to tabulate information that the nodal quasidiffusion equations can use to capture transport effects in full-core calculations.
The nodal inhibitor Coco is a critical target of leftward flow in Xenopus.
Schweickert, Axel; Vick, Philipp; Getwan, Maike; Weber, Thomas; Schneider, Isabelle; Eberhardt, Melanie; Beyer, Tina; Pachur, Anke; Blum, Martin
2010-04-27
Vertebrate laterality, which is manifested by asymmetrically placed organs [1], depends on asymmetric activation of the Nodal signaling cascade in the left lateral plate mesoderm [2]. In fish, amphibians, and mammals, a cilia-driven leftward flow of extracellular fluid acts upstream of the Nodal cascade [3-6]. The direct target of flow has remained elusive. In Xenopus, flow occurs at the gastrocoel roof plate (GRP) in the dorsal midline of the embryo [4, 7]. The GRP is bordered by a second, bilaterally symmetrical Nodal expression domain [8]. Here we identify the Nodal inhibitor Coco as a critical target of flow. Coco and Xenopus Nodal-related 1 (Xnr1) are coexpressed in the lateralmost ciliated GRP cells. Coco becomes downregulated on the left side of the GRP as a direct readout of flow. Ablation of flow prevented Coco repression, whereas Xnr1 expression was independent of flow. Loss of flow-induced laterality defects were rescued by knockdown of Coco on the left side. Parallel knockdown of Coco and Xnr1 in GRP cells restored laterality defects in flow-impaired embryos, demonstrating that Coco acted through GRP-expressed Xnr1. Coco thus acts as a critical target of flow, suggesting that symmetry is broken by flow-mediated left-asymmetric release of Nodal repression at the midline.
Influence of FDG-PET on primary nodal target volume definition for head and neck carcinomas.
van Egmond, Sylvia L; Piscaer, Vera; Janssen, Luuk M; Stegeman, Inge; Hobbelink, Monique G; Grolman, Wilko; Terhaard, Chris H
The role of 2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in routine diagnostic staging remains controversial. In case of discordance between FDG-PET and CT, a compromise has to be made between the risk of false positive FDG-PET and the risk of delaying appropriate salvage intervention. Second, with intensity modulated radiation therapy (IMRT), smaller radiation fields allow tissue sparing, but could also lead to more marginal failures. We retrospectively studied 283 patients with head and neck carcinoma scheduled for radiotherapy between 2002 and 2010. We analyzed the influence of FDG-PET/CT versus CT alone on defining nodal target volume definition and evaluated its long-term clinical results. Second, the location of nodal recurrences was related to the radiation regional dose distribution. In 92 patients, CT and FDG-PET, performed in mold, showed discordant results. In 33%, nodal staging was altered by FDG-PET. In 24%, FDG-PET also led to an alteration in nodal treatment, including a nodal upstage of 18% and downstage of 6%. In eight of these 92 patients, a regional recurrence occurred. Only two patients had a recurrence in the discordant node on FDG-PET and CT and both received a boost (high dose radiation). These results support the complementary value of FDG-PET/CT compared to CT alone in defining nodal target volume definition for radiotherapy of head and neck cancer.
Cilia are required for asymmetric nodal induction in the sea urchin embryo.
Tisler, Matthias; Wetzel, Franziska; Mantino, Sabrina; Kremnyov, Stanislav; Thumberger, Thomas; Schweickert, Axel; Blum, Martin; Vick, Philipp
2016-08-23
Left-right (LR) organ asymmetries are a common feature of metazoan animals. In many cases, laterality is established by a conserved asymmetric Nodal signaling cascade during embryogenesis. In most vertebrates, asymmetric nodal induction results from a cilia-driven leftward fluid flow at the left-right organizer (LRO), a ciliated epithelium present during gastrula/neurula stages. Conservation of LRO and flow beyond the vertebrates has not been reported yet. Here we study sea urchin embryos, which use nodal to establish larval LR asymmetry as well. Cilia were found in the archenteron of embryos undergoing gastrulation. Expression of foxj1 and dnah9 suggested that archenteron cilia were motile. Cilia were polarized to the posterior pole of cells, a prerequisite of directed flow. High-speed videography revealed rotating cilia in the archenteron slightly before asymmetric nodal induction. Removal of cilia through brief high salt treatments resulted in aberrant patterns of nodal expression. Our data demonstrate that cilia - like in vertebrates - are required for asymmetric nodal induction in sea urchin embryos. Based on these results we argue that the anterior archenteron represents a bona fide LRO and propose that cilia-based symmetry breakage is a synapomorphy of the deuterostomes.
Ougouag, Abderrafi Mohammed-El-Ami; Terry, William Knox
2002-04-01
The usual strategy for solving the neutron diffusion equation in two or three dimensions by nodal methods is to reduce the multidimensional partial differential equation to a set of ordinary differential equations (ODEs) in the separate spatial coordinates. This reduction is accomplished by “transverse integration” of the equation.1 For example, in three-dimensional Cartesian coordinates, the three-dimensional equation is first integrated over x and y to obtain an ODE in z, then over x and z to obtain an ODE in y, and finally over y and z to obtain an ODE in x. Then the ODEs are solved to obtain onedimensional solutions for the neutron fluxes averaged over the other two dimensions. These solutions are found in regions (“nodes”) small enough for the material properties and cross sections in them to be adequately represented by average values. Because the solution in each node is an exact analytical solution, the nodes can be much larger than the mesh elements used in finite-difference solutions. Then the solutions in the different nodes are coupled by applying interface conditions, ultimately fixing the solutions to the external boundary conditions.
On Formulations of Discontinuous Galerkin and Related Methods for Conservation Laws
NASA Technical Reports Server (NTRS)
Huynh, H. T.
2014-01-01
A formulation for the discontinuous Galerkin (DG) method that leads to solutions using the differential form of the equation (as opposed to the standard integral form) is presented. The formulation includes (a) a derivative calculation that involves only data within each cell with no data interaction among cells, and (b) for each cell, corrections to this derivative that deal with the jumps in fluxes at the cell boundaries and allow data across cells to interact. The derivative with no interaction is obtained by a projection, but for nodal-type methods, evaluating this derivative by interpolation at the nodal points is more economical. The corrections are derived using the approximate (Dirac) delta functions. The formulation results in a family of schemes: different approximate delta functions give rise to different methods. It is shown that the current formulation is essentially equivalent to the flux reconstruction (FR) formulation. Due to the use of approximate delta functions, an energy stability proof simpler than that of Vincent, Castonguay, and Jameson (2011) for a family of schemes is derived. Accuracy and stability of resulting schemes are discussed via Fourier analyses. Similar to FR, the current formulation provides a unifying framework for high-order methods by recovering the DG, spectral difference (SD), and spectral volume (SV) schemes. It also yields stable, accurate, and economical methods.
Schlange, Thomas; Arnold, Hans-Henning; Brand, Thomas
2002-07-01
A model of left-right axis formation in the chick involves inhibition of bone morphogenetic proteins by the antagonist Car as a mechanism of upregulating Nodal in the left lateral plate mesoderm. By contrast, expression of CFC, a competence factor, which is absolutely required for Nodal signaling in the lateral plate mesoderm is dependent on a functional BMP signaling pathway. We have therefore investigated the relationship between BMP and Nodal in further detail. We implanted BMP2 and Noggin-expressing cells into the left lateral plate and paraxial mesoderm and observed a strong upregulation of Nodal and its target genes Pitx2 and Nkx3.2. In addition Cfc, the Nodal type II receptor ActrIIa and Snr were found to depend on BMP signaling for their expression. Comparison of the expression domains of Nodal, Bmp2, Car and Cfc revealed co-expression of Nodal, Cfc and Bmp2, while Car and Nodal only partially overlapped. Ectopic application of BMP2, Nodal, and Car as well as combinations of this signaling molecules to the right lateral plate mesoderm revealed that BMP2 and Car need to synergize in order to specify left identity. We propose a novel model of left-right axis formation, which involves BMP as a positive regulator of Nodal signaling in the chick embryo.
Postmastectomy internal mammary nodal irradiation: a long-term outcome.
Aleknavičius, Eduardas; Atkočius, Vydmantas; Kuzmickienė, Irena; Steponavičienė, Rita
2014-01-01
The internal mammary lymph nodes (IMN) have been recognized as a potential site of regional breast cancer spread. The aim of this study was to evaluate the impact of internal mammary node radiotherapy (RT) to on clinical outcomes in breast cancer patients treated with mastectomy and postoperative radiation therapy. This cohort study included 588 patients with breast cancers located in the central and medial quadrants. IMN RT was applied to 320 patients and 268 patients did not receive it IMN RT. Inside the IMN RT group, 165 patients received external beam IMN irradiation (IMN-EB). Mastectomy combined with using Californium-252 neutron source implantation was applied to 155 patients (IMN-BT). Cox proportional hazards modeling was used to determine the influence of IMN RT on clinical outcome. Age, tumor size, lymph nodal status, adjuvant radiotherapy, chemotherapy and hormonal therapy were assessed. IMN-EB resulted in a significant improvement of distant metastasis-free survival, breast cancer-specific survival and overall survival (P=0.033, P=0.037 and P=0.011, respectively). The IMN-EB radiotherapy has a significant impact on event-free survival (HR, 0.67; 95% CI, 0.46-0.91; P=0.043) and breast cancer-specific survival (HR, 0.64; 95% CI, 45-0.91; P=0.013) in patients with moderate-risk (stage T1-2N1). There was no association between IMN RT and clinical outcomes of patients with high-risk disease (stage T3-4N2-3) in any of the study end points. The effects of IMN-EB radiotherapy on event-free survival and breast cancer-specific survival were benefit for women with moderate-risk breast cancer. Copyright © 2014 Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Catheter Ablation of Atypical Atrioventricular Nodal Reentrant Tachycardia.
Katritsis, Demosthenes G; Marine, Joseph E; Contreras, Fernando M; Fujii, Akira; Latchamsetty, Rakesh; Siontis, Konstantinos C; Katritsis, George D; Zografos, Theodoros; John, Roy M; Epstein, Lawrence M; Michaud, Gregory F; Anter, Elad; Sepahpour, Ali; Rowland, Edward; Buxton, Alfred E; Calkins, Hugh; Morady, Fred; Stevenson, William G; Josephson, Mark E
2016-11-22
Because of its low prevalence, data on atypical atrioventricular nodal reentrant tachycardia (AVNRT) are scarce, and the optimal ablation method has not been established. Our study aimed at assessing the efficacy and safety of conventional slow pathway ablation, as applied for typical cases, in atypical AVNRT. We studied 2079 patients with AVNRT subjected to slow pathway ablation. In 113 patients, mean age 48.5±18.1 years, 68 female, atypical AVNRT or coexistent atypical and typical AVNRT without other concomitant arrhythmia was diagnosed. Ablation data and outcomes were compared with a group of age- and sex-matched control patients with typical AVNRT. Fluoroscopy and radiofrequency current delivery times were not different in the atypical and typical groups, 20.3±12.2 versus 20.8±12.9 minutes (P=0.730) and 5.9±5.0 versus 5.5±4.5 minutes (P=0.650), respectively. Slow pathway ablation was accomplished from the right septum in 110 patients, and from the left septum in 3 patients, in the atypical group. There was no need for additional ablation lesions at other anatomic sites, and no cases of atrioventricular block were encountered. Recurrence rates of the arrhythmia were 5.6% in the atypical (6/108 patients) and 1.8% in the typical (2/111 patients) groups in the next 3 months following ablation (P=0.167). Conventional ablation at the anatomic area of the slow pathway is the therapy of choice for symptomatic AVNRT, regardless of whether the typical or atypical form is present. © 2016 American Heart Association, Inc.
TGF-β promotes glioma cell growth via activating Nodal expression through Smad and ERK1/2 pathways
Sun, Jing; Liu, Su-zhi; Lin, Yan; Cao, Xiao-pan; Liu, Jia-ming
2014-01-17
Highlights: •TGF-β promoted Nodal expression in glioma cells. •TGF-β promoted Nodal expression via activating Smad and ERK1/2 pathways. •TGF-β promotes glioma cell growth via activating Nodal expression. -- Abstract: While there were certain studies focusing on the mechanism of TGF-β promoting the growth of glioma cells, the present work revealed another novel mechanism that TGF-β may promote glioma cell growth via enhancing Nodal expression. Our results showed that Nodal expression was significantly upregulated in glioma cells when TGF-β was added, whereas the TGF-β-induced Nodal expression was evidently inhibited by transfection Smad2 or Smad3 siRNAs, and the suppression was especially significant when the Smad3 was downregulated. Another, the attenuation of TGF-β-induced Nodal expression was observed with blockade of the ERK1/2 pathway also. Further detection of the proliferation, apoptosis, and invasion of glioma cells indicated that Nodal overexpression promoted the proliferation and invasion of tumor cells and inhibited their apoptosis, resembling the effect of TGF-β addition. Downregulation of Nodal expression via transfection Nodal-specific siRNA in the presence of TGF-β weakened the promoting effect of the latter on glioma cells growth, and transfecting Nodal siRNA alone in the absence of exogenous TGF-β more profoundly inhibited the growth of glioma cells. These results demonstrated that while both TGF-β and Nodal promoted glioma cells growth, the former might exert such effect by enhancing Nodal expression, which may form a new target for glioma therapy.
Numerical simulations, analytical expressions, and observations of apsidal and nodal superhumps
NASA Astrophysics Data System (ADS)
Montgomery-Bobertz, Michele Marie
2004-10-01
We use theory and numerical simulations, as constrained by observations, to better understand nodal and apsidal superhumps in Cataclysmic Variable (CV) systems. We verify the postulated tilted accretion disk theory by generating artificial light curves and associated Fourier transforms containing nodal and/or apsidal superhumps from numerical simulations of tilted accretion disks. We consider main sequence secondaries only. Apsidal superhumps are adequately described by dynamical motions of particles in a progradely precessing accretion disk due to a tidally perturbing secondary less the pressure effects due to the spiral arms. Nodal superhumps are numerically and kinematically described by the secondary tidally inducing a retrograde precession of a disk tilted out of the orbital plane ˜3° 10°. We suggest that disk tilt is neither caused by thermal instabilities nor tidal instabilities that induce apsidal precession. We find that the disk cannot remain tilted by a steady accretion rate typical of SU UMa's that strikes the inner disk. We find that the accretion disk tilt is a pattern that the disk and secondary pass through, and that the secondary maintains facing the minor axis of the elliptical accretion disk. We extend the mass ratio lower to q = 0.025 and the upper limit to q = 0.35 for apsidally precessing systems. We find no mass ratio limit on nodal precession in our simulations with an imposed disk tilt. Our analytical expressions and numerical simulations agree with observations, on average. For nodal precession, we apply the lunisolar precessional theory to CVs. The ratio of our analytical expressions and numerical simulations of apsidal to-nodal precessions is nearly 2:1, the same ratio found in observations and in the lunisolar precessional theory. We question whether V1159 Ori and ER UMa truly are nodally precessing systems. We suggest that TV Col has a non-main sequence secondary and that an extended campaign be conducted. We find that primary mass
Pitch-Angle Diffusion in Canonical Coordinates: A Theoretical Formulation.
1981-08-21
begenerated from the above set by procedures analogous to the Rayleigh- Schr ~ dinger perturbation theory used in quantum mechanics. The avail-ability...the time -independent Schrbdinger equation (d 2 gn/d 2 ) + k g n = 0. (30) This is achieved by introducing the new variable =f (Dzz/Dz,z,)dz’, (31) 0...Radiation Belts 20 VISTRACT (Continu, on reveres aide if neesseary and Identify by block numb.,) -4he equation for pitch-angle diffusion (at constant
NASA Astrophysics Data System (ADS)
Ilas, Germina
In the first part, an accurate and fast computational method is presented as an alternative to the Monte Carlo or deterministic transport theory codes currently used to determine the subcriticality of spent fuel storage lattices. The method is capable of analyzing storage configurations with simple or complex lattice cell geometry. It is developed based on two-group nodal diffusion theory, with the nodal cross sections and discontinuity factors determined from continuous-energy Monte Carlo simulations of each unique node (spent fuel assembly type). Three different approaches are developed to estimate the node-averaged diffusion coefficient. The applicability and the accuracy of the nodal method are assessed in two-dimensional geometry through several benchmark configurations typical at Savannah River Site. It is shown that the multiplication constant of the analyzed configurations is within 1% of the MCNP results. In the second part, the high-order cross section homogenization method, recently developed by McKinley and Rahnema, is implemented in the context of two-group nodal diffusion theory. The method corrects the generalized equivalence theory homogenization parameters for the effect of the core environment. The reconstructed fine-mesh (fuel pin) flux and power distributions are a natural byproduct of this method. The method was not tested for multigroup problems, where it was assumed that the multigroup flux expansion in terms of the perturbation parameter is a convergent series. Here the applicability of the method to two-group problems is studied, and it is shown that the perturbation expansion series converges for the multigroup case. A two-group nodal diffusion code with a bilinear intra-nodal flux shape is developed for the implementation of the high-order homogenization method in the context of the generalized equivalence theory. The method is tested by using as a benchmark a core configuration typical of a BWR in slab geometry, which has large
A new formulation of the conservation equations of fluid dynamics
NASA Technical Reports Server (NTRS)
Vinokur, M.
1974-01-01
The computation of time-dependent flows has inspired a new, higher-dimensional formulation of the conservation equations of fluid dynamics in which time is treated as a fourth coordinate. The formulation is derived for a constant-density flow, and then extended to a variable-density flow by introducing a fifth, fictitious coordinate. This new coordinate can also act as a source coordinate, so that external source terms can be included. The analysis is carried out for both incompressible, stratified flow, and compressible equilibrium flow. The results are then extended to non-equilibrium and magnetohydrodynamic flows. Several applications of the new formulation to the computation of time-dependent flows are discussed.
Nonlinear finite element analysis: An alternative formulation
NASA Technical Reports Server (NTRS)
Merazzi, S.; Stehlin, P.
1980-01-01
A geometrical nonlinear analysis based on an alternative definition of strain is presented. Expressions for strain are obtained by computing the change in length of the base vectors in the curvilinear element coordinate system. The isoparametric element formulation is assumed in the global Cartesian coordinate system. The approach is based on the minimization of the strain energy, and the resulting nonlinear equations are solved by the modified Newton method. Integration of the first and second variation of the strain energy is performed numerically in the case of two and three dimensional elements. Application is made to a simple long cantilever beam.
Development of a phenotyping platform for high throughput screening of nodal root angle in sorghum.
Joshi, Dinesh C; Singh, Vijaya; Hunt, Colleen; Mace, Emma; van Oosterom, Erik; Sulman, Richard; Jordan, David; Hammer, Graeme
2017-01-01
In sorghum, the growth angle of nodal roots is a major component of root system architecture. It strongly influences the spatial distribution of roots of mature plants in the soil profile, which can impact drought adaptation. However, selection for nodal root angle in sorghum breeding programs has been restricted by the absence of a suitable high throughput phenotyping platform. The aim of this study was to develop a phenotyping platform for the rapid, non-destructive and digital measurement of nodal root angle of sorghum at the seedling stage. The phenotyping platform comprises of 500 soil filled root chambers (50 × 45 × 0.3 cm in size), made of transparent perspex sheets that were placed in metal tubs and covered with polycarbonate sheets. Around 3 weeks after sowing, once the first flush of nodal roots was visible, roots were imaged in situ using an imaging box that included two digital cameras that were remotely controlled by two android tablets. Free software (openGelPhoto.tcl) allowed precise measurement of nodal root angle from the digital images. The reliability and efficiency of the platform was evaluated by screening a large nested association mapping population of sorghum and a set of hybrids in six independent experimental runs that included up to 500 plants each. The platform revealed extensive genetic variation and high heritability (repeatability) for nodal root angle. High genetic correlations and consistent ranking of genotypes across experimental runs confirmed the reproducibility of the platform. This low cost, high throughput root phenotyping platform requires no sophisticated equipment, is adaptable to most glasshouse environments and is well suited to dissect the genetic control of nodal root angle of sorghum. The platform is suitable for use in sorghum breeding programs aiming to improve drought adaptation through root system architecture manipulation.
Utility of SUVmax on (18) F-FDG PET in detecting cervical nodal metastases.
Lim, Rebecca S M; Ramdave, Shakher; Beech, Paul; Billah, Baki; Karim, Md Nazmul; Smith, Julian A; Safdar, Adnan; Sigston, Elizabeth
2016-11-08
The presence of cervical lymph node metastasis is an important prognostic factor for patients with head and neck squamous cell carcinomas (HNSCC). Accurate assessment of lymph node metastasis in these patients is essential for appropriate prognostic and management purposes. Here, we evaluated the effectiveness of the maximum standardized uptake value (SUVmax) on positron emission tomography (PET) in assessing lymph node metastasis in HNSCC prior to surgery. A retrospective review of 74 patients with HNSCC who underwent PET/CT prior to neck dissection were examined. Pre-operative PET/CT scans were reviewed by two experienced nuclear medicine physicians and SUVmax of the largest node in each nodal basin documented. These were compared with the histology results of the neck dissection. A total of 359 nodal basins including 86 basins with metastatic nodes were evaluated. A nodal SUVmax ≥3.16 yielded a sensitivity of 74.4 % and specificity of 84.9 % in detecting metastatic nodes. The nodal SUVmax/Liver SUVmax ratio was found on receiver operating characteristic (ROC) to be effective in detecting metastatic nodes with an area under ROC curve of 0.90. A nodal SUVmax/Liver SUVmax ratio ≥0.90 yielded a sensitivity of 74.1 % and specificity of 93.4 %. By comparison, visual inspection yielded sensitivities of 66.3 and 61.6 % in observers 1 and 2 respectively. The corresponding specificities were 77.7 and 86.5 %. Nodal SUVmax and nodal SUVmax/liver SUVmax are both useful in the pre-operative detection of metastatic nodes with the latter being superior to visual inspection. The ratio is likely to be more useful as it corrects for inter-scanner variability.
Extra-nodal extension is a significant prognostic factor in lymph node positive breast cancer
Aziz, Sura; Wik, Elisabeth; Davidsen, Benedicte; Aas, Hans; Aas, Turid; Akslen, Lars A.
2017-01-01
Presence of lymph node (LN) metastasis is a strong prognostic factor in breast cancer, whereas the importance of extra-nodal extension and other nodal tumor features have not yet been fully recognized. Here, we examined microscopic features of lymph node metastases and their prognostic value in a population-based cohort of node positive breast cancer (n = 218), as part of the prospective Norwegian Breast Cancer Screening Program NBCSP (1996–2009). Sections were reviewed for the largest metastatic tumor diameter (TD-MET), nodal afferent and efferent vascular invasion (AVI and EVI), extra-nodal extension (ENE), number of ENE foci, as well as circumferential (CD-ENE) and perpendicular (PD-ENE) diameter of extra-nodal growth. Number of positive lymph nodes, EVI, and PD-ENE were significantly increased with larger primary tumor (PT) diameter. Univariate survival analysis showed that several features of nodal metastases were associated with disease-free (DFS) or breast cancer specific survival (BCSS). Multivariate analysis demonstrated an independent prognostic value of PD-ENE (with 3 mm as cut-off value) in predicting DFS and BCSS, along with number of positive nodes and histologic grade of the primary tumor (for DFS: P = 0.01, P = 0.02, P = 0.01, respectively; for BCSS: P = 0.02, P = 0.008, P = 0.02, respectively). To conclude, the extent of ENE by its perpendicular diameter was independently prognostic and should be considered in line with nodal tumor burden in treatment decisions of node positive breast cancer. PMID:28199370
Psychiatrists' use of formulation
Hughes, Patricia M.
2016-01-01
Both psychologists and psychiatrists are trained to write formulations of their patients' illnesses, with some differences in how they do this. Psychologists focus on psychological understanding, while psychiatrists' formulation brings together aetiology, functioning and a management plan. Mohtashemi et al's study records how some psychiatrists understand formulation and its usefulness. Time pressure was an important barrier to making a full formulation, and some believed the medical role of the psychiatrist was a priority. The study illustrates some of the challenges facing psychiatrists working in the NHS in terms of maintaining high clinical standards and a holistic approach to patient care. PMID:27512593
[Lipid formulations of amphotericin].
Botero, Martha C; Puentes-Herrera, Marcela; Cortés, Jorge A
2014-10-01
Amphotericin B deoxycholate use has increased during the past years in parallel with the increase in the number of immunosuppressed patients suffering invasive fungal infections. This drug is associated with a high rate of side effects, especially renal toxicity. Lipid formulations (liposomal, lipid complex, colloidal suspension and the Indian liposomal formulation) have been developed, which share the same antifungal spectrum but differ in efficacy and toxicity. A review of amphotericin lipid formulations is presented, focusing on differences in efficacy and, especially renal toxicity. The main problem for use of these formulations in Latin America is their highcost.
Minerva: Cylindrical coordinate extension for Athena
NASA Astrophysics Data System (ADS)
Skinner, M. Aaron; Ostriker, Eve C.
2013-02-01
Minerva is a cylindrical coordinate extension of the Athena astrophysical MHD code of Stone, Gardiner, Teuben, and Hawley. The extension follows the approach of Athena's original developers and has been designed to alter the existing Cartesian-coordinates code as minimally and transparently as possible. The numerical equations in cylindrical coordinates are formulated to maintain consistency with constrained transport (CT), a central feature of the Athena algorithm, while making use of previously implemented code modules such as the Riemann solvers. Angular momentum transport, which is critical in astrophysical disk systems dominated by rotation, is treated carefully.
Heavy fermions: From nodal metals to super-spins
NASA Astrophysics Data System (ADS)
Ramires Neves de Oliveira, Aline
Condensed matter physics is an area of research which lies at a sweet spot between two complementary perspectives: the atomistic point of view which takes into account all the details of the system of interest; and the framework of universality and emergent phenomena, which allows us to make drastic simplifications to the microscopic description of materials while still being able to explain much of the experimentally observed phenomena. This thesis addresses problems from both perspectives, focusing on heavy fermion systems. Heavy fermion systems are prototype materials for the study of strongly correlations and quantum criticality. Theoretical understanding of these systems is important for the design of new materials and for the fundamental understanding of quantum critical phenomena. This thesis is strongly motivated by recent experiments in an intrinsically quantum critical material, beta-YbAlB 4. This system shows anomalous critical exponents in transport and thermodynamics. In Chapter 2 we construct a phenomenological theory for the heavy fermion metal beta-YbAlB4 based on the Anderson model, taking into account the peculiarities of this specific material. We analyze the consequences of a non-trivial, momentum-dependent, hybridization matrix between f-electrons and conduction electrons, which gives rise to a nodal metal with unusual dispersion and singular thermodynamic properties, in accordance with experiments. In Chapter 3 we analyze the Electron Spin Resonance experiments in this same material and propose a theory including spin-orbit coupling, crystal electric fields and hyperfine coupling which can account for many of the features of the experimentally observed signal. Within a broader perspective on heavy fermion systems, the absence of a single unified theoretical description which can account for the plethora of phenomena observed in this class of materials also motivates us to consider new theoretical approaches. In Chapter 4 we generalize the
Gong, Wenchen; Sun, Baocun; Sun, Huizhi; Zhao, Xiulan; Zhang, Danfang; Liu, Tieju; Zhao, Nan; Gu, Qiang; Dong, Xueyi; Liu, Fang
2017-01-01
Nodal signaling plays several vital roles in the embryogenesis process. However, its reexpression in breast cancer is correlated with cancer progression, metastasis and poor prognosis. Recently, Nodal has also been reported to regulate self-renewal capacity in pancreatic cancer. This study aimed to explore the role of Nodal in breast cancer stem cells (BCSCs) and the underlying mechanisms. Therefore, the immunohistochemistry staining of Nodal in 135 human breast cancer cases was performed to analyzed the relationship of Nodal signaling, clinical outcomes and BCSC marker. And the results showed that high Nodal expression was positively correlated with poor prognosis and BCSC marker expression in breast cancer samples. We further assessed the effects of Nodal in regulating the BCSC properties in breast cancer cell lines and xenografts. Then, SB431542 was administered in vitro and in vivo to explore the function of the Smad2/3 pathway. And we demonstrated that Nodal signaling up-regulated the expression of ALDH1, CD44, CD133, Sox2, Oct4 and Nanog by activating the Smad2/3 pathway, thereby enhancing the tumorigenicity and sphere-forming ability of breast cancer cells. Furthermore, treatment with SB431542 could inhibit the properties of BCSCs in vitro and in vivo. In conclusion, these findings indicate that Nodal signaling may play a vital role in maintaining the BCSC phenotype in breast cancer and serve as a potential target to explore BCSC-specific therapies. PMID:28401007
Topological nodal-line fermions in spin-orbit metal PbTaSe2
Bian, Guang; Chang, Tay-Rong; Sankar, Raman; ...
2016-02-02
Here we discuss how topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe2 with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe2 are not only protected by the reflection symmetry but also characterizedmore » by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems.« less
The impact of surgical technique on neck dissection nodal yield: making a difference.
Lörincz, Balazs B; Langwieder, Felix; Möckelmann, Nikolaus; Sehner, Susanne; Knecht, Rainald
2016-05-01
The nodal yield of neck dissections is an independent prognostic factor in several types of head and neck cancer. The authors aimed to determine whether the applied dissection technique has a significant impact on nodal yield. This is a single-institution, prospective study with internal control group (level of evidence: 2A). Data of 150 patients undergoing 223 neck dissections between February 2011 and March 2013 have been collected in a comprehensive cancer centre. Eighty-two patients underwent neck dissection with unwrapping the cervical fascia from lateral to medial, while 68 patients were operated without specifically unwrapping the fascia, in a caudal to cranial fashion. The standardised, horizontal neck dissection technique along the fascial planes resulted in a significantly higher nodal count in Levels I, II, III and IV, as well as in terms of overall nodal yield (mean: n = 22.53) than that of the vertical dissection applied in the control group (mean: n = 15.00). This is the first publication showing a direct correlation between neck dissection nodal yield and surgical technique. Therefore, it is paramount to optimise the applied surgical concept to maximise the oncological benefit.
Interplay between short-range correlated disorder and Coulomb interaction in nodal-line semimetals
NASA Astrophysics Data System (ADS)
Wang, Yuxuan; Nandkishore, Rahul M.
2017-09-01
In nodal-line semimetals, Coulomb interactions and short-range correlated disorder are both marginal perturbations to the clean noninteracting Hamiltonian. We analyze their interplay using a weak-coupling renormalization group approach. In the clean case, the Coulomb interaction has been found to be marginally irrelevant, leading to Fermi liquid behavior. We extend the analysis to incorporate the effects of disorder. The nodal line structure gives rise to kinematical constraints similar to that for a two-dimensional Fermi surface, which plays a crucial role in the one-loop renormalization of the disorder couplings. For a twofold degenerate nodal loop (Weyl loop), we show that disorder flows to strong coupling along a unique fixed trajectory in the space of symmetry inequivalent disorder couplings. Along this fixed trajectory, all symmetry inequivalent disorder strengths become equal. For a fourfold degenerate nodal loop (Dirac loop), disorder also flows to strong coupling, however, the strengths of symmetry inequivalent disorder couplings remain different. We show that feedback from disorder reverses the sign of the beta function for the Coulomb interaction, causing the Coulomb interaction to flow to strong coupling as well. However, the Coulomb interaction flows to strong coupling asymptotically more slowly than disorder. Extrapolating our results to strong coupling, we conjecture that at low energies nodal line semimetals should be described by a noninteracting nonlinear sigma model. We discuss the relation of our results with possible many-body localization at zero temperatures in such materials.
The distance between breast cancer and the skin is associated with axillary nodal metastasis.
Eom, Yong Hwa; Kim, Eun Jin; Chae, Byung Joo; Song, Byung Joo; Jung, Sang Seol
2015-06-01
More superficially located tumors may be more likely than deeper tumors to metastasize to the axillary nodes via the lymphatics. The aim of this study was to determine whether breast cancer distance from the skin affects axillary node metastasis, ipsilateral breast cancer recurrence, or recurrence-free survival. A total of 1,005 consecutive patients with breast cancer who underwent surgery between January 2003 and December 2009 were selected. The distance of the tumor from the skin was measured from the skin to the most anterior hypoechoic leading edge of the lesion. In total, 603 (68%) patients had no axillary nodal metastasis, and 288 (32%) had axillary nodal metastasis. A breast cancer distance from the skin <3 mm induced more axillary nodal metastasis (P = 0.039). However, no significant correlation was observed between breast cancer distance from the skin <3 mm and ipsilateral breast cancer recurrence (P = 0.788) or recurrence-free survival (P = 0.353). Breast cancers located closer to the skin had a higher incidence of axillary nodal metastasis. Therefore, tumor distance from the skin should be considered when evaluating a patient with breast cancer and considering the risk of nodal metastasis. © 2015 Wiley Periodicals, Inc.
Topological nodal-line fermions in spin-orbit metal PbTaSe2
Bian, Guang; Chang, Tay-Rong; Sankar, Raman; Xu, Su-Yang; Zheng, Hao; Neupert, Titus; Chiu, Ching-Kai; Huang, Shin-Ming; Chang, Guoqing; Belopolski, Ilya; Sanchez, Daniel S.; Neupane, Madhab; Alidoust, Nasser; Liu, Chang; Wang, BaoKai; Lee, Chi-Cheng; Jeng, Horng-Tay; Zhang, Chenglong; Yuan, Zhujun; Jia, Shuang; Bansil, Arun; Chou, Fangcheng; Lin, Hsin; Hasan, M. Zahid
2016-02-02
Here we discuss how topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe_{2} with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe_{2} are not only protected by the reflection symmetry but also characterized by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems.
Topological nodal-line fermions in spin-orbit metal PbTaSe2
Bian, Guang; Chang, Tay-Rong; Sankar, Raman; Xu, Su-Yang; Zheng, Hao; Neupert, Titus; Chiu, Ching-Kai; Huang, Shin-Ming; Chang, Guoqing; Belopolski, Ilya; Sanchez, Daniel S.; Neupane, Madhab; Alidoust, Nasser; Liu, Chang; Wang, BaoKai; Lee, Chi-Cheng; Jeng, Horng-Tay; Zhang, Chenglong; Yuan, Zhujun; Jia, Shuang; Bansil, Arun; Chou, Fangcheng; Lin, Hsin; Hasan, M. Zahid
2016-01-01
Topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe2 with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe2 are not only protected by the reflection symmetry but also characterized by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems. PMID:26829889
Role of Nodal-PITX2C signaling pathway in glucose-induced cardiomyocyte hypertrophy.
Su, Dongmei; Jing, Sun; Guan, Lina; Li, Qian; Zhang, Huiling; Gao, Xiaobo; Ma, Xu
2014-06-01
Pathological cardiac hypertrophy is a major cause of morbidity and mortality in cardiovascular disease. Recent studies have shown that cardiomyocytes, in response to high glucose (HG) stimuli, undergo hypertrophic growth. While much work still needs to be done to elucidate this important mechanism of hypertrophy, previous works have showed that some pathways or genes play important roles in hypertrophy. In this study, we showed that sublethal concentrations of glucose (25 mmol/L) could induce cardiomyocyte hypertrophy with an increase in the cellular surface area and the upregulation of the atrial natriuretic peptide (ANP) gene, a hypertrophic marker. High glucose (HG) treatments resulted in the upregulation of the Nodal gene, which is under-expressed in cardiomyocytes. We also determined that the knockdown of the Nodal gene resisted HG-induced cardiomyocyte hypertrophy. The overexpression of Nodal was able to induce hypertrophy in cardiomyocytes, which was associated with the upregulation of the PITX2C gene. We also showed that increases in the PITX2C expression, in response to Nodal, were mediated by the Smad4 signaling pathway. This study is highly relevant to the understanding of the effects of the Nodal-PITX2C pathway on HG-induced cardiomyocyte hypertrophy, as well as the related molecular mechanisms.
Saab, Jad; Santos-Zabala, Maria Laureana; Loda, Massimo; Stack, Edward C; Hollmann, Travis J
2017-06-13
Melanoma is a potentially lethal form of skin cancer for which the current standard therapy is complete surgical removal of the primary tumor followed by sentinel lymph node biopsy when indicated. Histologic identification of metastatic melanoma in a sentinel node has significant prognostic and therapeutic implications, routinely guiding further surgical management with regional lymphadenectomy. While melanocytes in a lymph node can be identified by routine histopathologic and immunohistochemical examination, the distinction between nodal nevus cells and melanoma can be morphologically problematic. Previous studies have shown that malignant melanoma can over-express metabolic genes such as fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC). This immunohistochemical study aims to compare the utility of FASN and ACC in differentiating sentinel lymph nodes with metastatic melanomas from those with benign nodal nevi in patients with cutaneous melanoma. Using antibodies against FASN and ACC, 13 sentinel lymph nodes from 13 patients with metastatic melanoma and 14 lymph nodes harboring benign intracapsular nevi from 14 patients with cutaneous malignant melanoma were examined. A diagnosis of nodal melanoma was based on cytologic atypia and histologic comparison with the primary melanoma. All nodal nevi were intracapsular and not trabecular. Immunohistochemistry for Melan-A, S100, human melanoma black 45 (HMB45), FASN, and ACC were performed. The percentage of melanocytes staining with HMB45, FASN, and ACC was determined and graded in 25% increments; staining intensity was graded as weak, moderate, or strong. All metastatic melanomas tested had at least 25% tumor cell staining for both FASN and ACC. Greater than 75% of the tumor cells stained with FAS in 7/13 cases and for ACC in 5/12 cases. Intensity of staining was variable; strong staining for FASN and ACC was observed in 69% and 50% of metastatic melanoma, respectively. HMB45 was negative in 40% of nodal
Autoantibody responses to nodal and paranodal antigens in chronic inflammatory neuropathies.
Mathey, E K; Garg, N; Park, S B; Nguyen, T; Baker, S; Yuki, N; Yiannikas, C; Lin, C S; Spies, J M; Ghaoui, R; Barnett, M H; Vucic, S; Pollard, J D; Kiernan, M C
2017-08-15
Autoantibodies to nodal/paranodal proteins have been reported in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). To determine the frequency of anti-paranodal antibodies in our cohort of CIDP patients and to validate the presence anti-nodal antibodies in MMN, sera were screened for IgG against human neurofascin 155, contactin-1, neurofascin 186 and gliomedin using ELISA. In CIDP patients, 7% were anti-NF155 IgG4 positive and 7% were anti-CNTN1 IgG4 positive. Positive results were confirmed using cell based assays and indirect immunofluorescence on teased nerve fibres. We did not detect IgG autoantibodies against these nodal/paranodal antigens in MMN patients. Copyright © 2017 Elsevier B.V. All rights reserved.
The role of nodal and internodal responses in gravitropism and autotropism in Galium aparine L
NASA Technical Reports Server (NTRS)
Heathcote, D. G.; Brown, A. H. (Principal Investigator)
1987-01-01
This time course and location of gravitropically induced curvatures in stems of goosegrass (Gallium aparine L.), a member of the Rubiaceae, have been investigated. In the early stages of the response (0-5 h), curvature develops throughout the growing region, and is followed by an autotropic straightening which affects the internodes only, leading to the production of essentially straight internodes some 15 h after the onset of gravistimulation. Curvatures developing in the nodal regions, however, continue to increase over this period, and are not subject to reversal by autotropism. The nodal curvatures are not entirely dependent on the presence of any other part of the plant, since marked curvatures can be induced in isolated nodal segments. This pattern of response leads ultimately to correction of the growth direction of the plant by means of curvature responses confined exclusively to the nodes, despite the initial participation of both nodes and internodes in the gravitropic reaction.
Potential for Infra-Nodal Heart Block and Cardiogenic Shock With Propofol Administration
Olson, Nicholas; Lim, Michael J.; Ferreira, Scott W.; Mehdirad, Ali A.
2013-01-01
We report a case of infra-nodal complete heart block and cardiogenic shock in a previously healthy 64-year-old man after administration of 180 mg of intravenous Propofol. Although bradycardia, hypotension, and heart block are commonly seen with propofol administration, such findings are transient and respond quickly to administration of vagolytic or sympathomimetic agents suggesting an AV nodal mechanism of heart block. Sustained left ventricular systolic dysfunction and cardiogenic shock by an alternative, non-autonomic mechanism has also been described in the setting of Propofol administration. Our case is the first to note sustained complete infra-nodal heart block in this setting. Early recognition of such a complication, restoration of atrio-ventricular (A-V) synchrony with dual chamber pacing, and aggressive circulatory support is essential in bridging such patients to recovery.
Hu, Haili; Liu, Jianjun; Fan, Zhigang
2013-07-29
In this paper we succeeded in deriving changes in the nodal positions of aberrations that belong to the fifth-order class in pupil dependence by applying a system level pupil decentration vector. Our treatment is specifically for rotationally symmetric multi-mirror optical designs that simply use an offset pupil as a means of creating an unobscured optical design. When the pupil is offset, only the vectors to determine the node locations are modified by the pupil decentration vector, while the nodal properties originally developed for titled/decentered optical systems are retained. In general, the modifications to the nodal vectors for any particular aberration type are contributed only by terms of higher order pupil dependence.
Topological nodal line semimetals in the CaP3 family of materials
NASA Astrophysics Data System (ADS)
Xu, Qiunan; Yu, Rui; Fang, Zhong; Dai, Xi; Weng, Hongming
2017-01-01
By using first-principles calculations and a k .p model analysis, we propose that the three-dimensional topological nodal line semimetal state can be realized in the CaP3 family of materials, which includes CaP3,CaAs3,SrP3,SrAs3, and BaAs3, when spin-orbit coupling (SOC) is ignored. The closed topological nodal line near the Fermi energy is protected by time reversal symmetry and spatial inversion symmetry. Moreover, drumheadlike two-dimensional surface states are also obtained on the c -direction surface of these materials. When SOC is included, the gaps open along the nodal line and these materials become strong topological insulators with Z2 indices as (1 ;010 ) .
Doping-Dependent Nodal Fermi Velocity in Bi-2212 Revealed by High-Resolution ARPES
Vishik, I. M.
2011-08-19
The improved resolution of laser-based angle-resolved photoemission spectroscopy (ARPES) allows reliable access to fine structures in the spectrum. We present a systematic, doping-dependent study of a recently discovered low-energy kink in the nodal dispersion of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212), which demonstrates the ubiquity and robustness of this kink in underdoped Bi-2212. The renormalization of the nodal velocity due to this kink becomes stronger with underdoping, revealing that the nodal Fermi velocity is non-universal, in contrast to assumed phenomenology. This is used together with laser-ARPES measurements of the gap velocity, v{sub 2}, to resolve discrepancies with thermal conductivity measurements.
Single Nodal Loop of Accidental Degeneracies in Minimal Symmetry: Triclinic CaAs3
NASA Astrophysics Data System (ADS)
Quan, Y.; Yin, Z. P.; Pickett, W. E.
2017-04-01
The existence of closed loops of degeneracies in crystals has been intimately connected with associated crystal symmetries, raising the following question: What is the minimum symmetry required for topological character, and can one find an example? Triclinic CaAs3 , in the space group P 1 ¯ with only a center of inversion, has been found to display, without need for tuning, a nodal loop of accidental degeneracies with topological character, centered on one face of the Brillouin zone that is otherwise fully gapped. The small loop is very flat in energy, yet is cut four times by the Fermi energy, a condition that results in an intricate repeated touching of inversion related pairs of Fermi surfaces at Weyl points. Spin-orbit coupling lifts the fourfold degeneracy along the loop, leaving trivial Kramers pairs. With its single nodal loop that emerges without protection from any point group symmetry, CaAs3 represents the primal "hydrogen atom" of nodal loop systems.
RW Per - Nodal motion changes its amplitude by 1.4 mag
NASA Technical Reports Server (NTRS)
Schaefer, Bradley E.; Fried, Robert E.
1991-01-01
RW Per was found to have large secular changes in its eclipse amplitude. In blue light, for example, the amplitude was 3.2 mag in the early 1900s, 2.2 mag in the late 1960s, and 1.75 mag in 1990. Throughout this time, the brightness at maximum was constant in all colors. It is shown that the only possible explanation is nodal motion, where the inclination varies with a period of roughly 100,000 yr. The nodal motion is caused by a third star, for which the light curve, the colors, and the O - C curve already provide evidence. Thus, RW Per is only the fourth known star with large changes of eclipse amplitude and is only the second example of nodal motion.
Dirac nodal lines and induced spin Hall effect in metallic rutile oxides
NASA Astrophysics Data System (ADS)
Sun, Yan; Zhang, Yang; Liu, Chao-Xing; Felser, Claudia; Yan, Binghai
2017-06-01
We have found Dirac nodal lines (DNLs) in the band structures of metallic rutile oxides IrO2, OsO2, and RuO2 and have revealed a large spin Hall conductivity contributed by these nodal lines, which explains a strong spin Hall effect (SHE) of IrO2 discovered recently. Two types of DNLs exist. The first type forms DNL networks that extend in the whole Brillouin zone and appears only in the absence of spin-orbit coupling (SOC), which induces surface states on the boundary. Because of SOC-induced band anticrossing, a large intrinsic SHE can be realized in these compounds. The second type appears at the Brillouin zone edges and is stable against SOC because of the protection of nonsymmorphic symmetry. Besides reporting these DNL materials, our work reveals the general relationship between DNLs and the SHE, indicating a way to apply Dirac nodal materials for spintronics.
Constructing a polynomial whose nodal set is the three-twist knot 52
NASA Astrophysics Data System (ADS)
Dennis, Mark R.; Bode, Benjamin
2017-06-01
We describe a procedure that creates an explicit complex-valued polynomial function of three-dimensional space, whose nodal lines are the three-twist knot 52. The construction generalizes a similar approach for lemniscate knots: a braid representation is engineered from finite Fourier series and then considered as the nodal set of a certain complex polynomial which depends on an additional parameter. For sufficiently small values of this parameter, the nodal lines form the three-twist knot. Further mathematical properties of this map are explored, including the relationship of the phase critical points with the Morse-Novikov number, which is nonzero as this knot is not fibred. We also find analogous functions for other simple knots and links. The particular function we find, and the general procedure, should be useful for designing knotted fields of particular knot types in various physical systems.
Formulation of Complex Action Theory
NASA Astrophysics Data System (ADS)
Nagao, K.; Nielsen, H. B.
2011-12-01
We formulate a complex action theory which includes operators of coordinate and momentum hat{q} and hat{p} being replaced with non-hermitian operators hat{q}_{new} and hat{p}_{new}, and their eigenstates | q >_{new} and | p >_{new} with complex eigenvalues q and p. Introducing a philosophy of keeping the analyticity in path integration variables, we define a modified set of complex conjugate, real and imaginary parts, hermitian conjugates and bras, and explicitly construct hat{q}_{new}, hat{p}_{new}, |q >_{new} and |p >_{new} by formally squeezing coherent states. We also pose a theorem on the relation between functions on the phase space and the corresponding operators. Only in our formalism can we describe a complex action theory or a real action theory with complex saddle points in the tunneling effect etc. in terms of bras and kets in the functional integral. Furthermore, in a system with a non-hermitian diagonalizable bounded Hamiltonian, we show that the mechanism to obtain a hermitian Hamiltonian after a long time development proposed in our paper [Prog. Theor. Phys. 125 (2011), 633] works also in the complex coordinate formalism. If the hermitian Hamiltonian is given in a local form, a conserved probability current density can be constructed with two kinds of wave functions.
The 18.6 yr nodal modulation in the tides of Southern European coasts
NASA Astrophysics Data System (ADS)
Shaw, A. G. P.; Tsimplis, M. N.
2010-02-01
The nodal modulation of the diurnal ( K1 and O1) and semi-diurnal ( M2 and K2) tidal constituents at the coasts of the Mediterranean Sea and the eastern Atlantic is estimated and its spatial variability mapped. Fourteen hourly tide gauge records each spanning more than 18 years are considered in this analysis. Ten tide gauges are located in the Mediterranean Sea and four in the Bay of Biscay. The nodal modulation of the most energetic tidal constituent ( M2) reaches up to 5 cm at the eastern Atlantic coasts, while within the Mediterranean Sea its modulation is in general less than 1.1 cm. The largest K2 nodal modulation found is 3.7 cm in the eastern Atlantic coasts. In the Mediterranean Sea, smaller modulation amplitudes, ranging between 0.4 and 1.4 cm are found. The K1 tide constituent has the largest amplitude nodal modulation within the Mediterranean Sea of 1.9 cm in the north Adriatic Sea, which is also larger than the modulation of this constituent at the eastern Atlantic coasts. The O1 tide constituent has the highest amplitude nodal modulation (1.4 cm) at the eastern Atlantic coasts. In the Mediterranean Sea the maximum value is 1 cm in the north Adriatic Sea. The derived nodal modulations of the diurnal and semi-diurnal constituents follow, in general, the equilibrium tidal theory. The tidal amplitudes for all four components do not indicate significant secular trends for most tide gauges. The tidal phases indicate significant negative trends for all four tidal constituents within the central and eastern Mediterranean Sea.
Zaman, Maseeh uz; Fatima, Nosheen; Sajjad, Zafar; Akhtar, Jaweed; Islam, Najmul; Masood, Qamar; Ahmed, Asma
2012-01-01
In papillary and follicular thyroid cancers (PTC, FTC), nodal and distant metastasis are generally considered important determinants of recurrence and survival, respectively. However, there is no consensus about the threshold primary tumour size (PTS) for these determinants. The aim of this study was to assess size relationships for developing nodal, pulmonary, bone and overall distant metastases. This prospective study covered 139 (93 females and 46 males) consecutive biopsy proven patients with PTC (114/139, mean age 41.0 ± 15.7 years, M: F, 35%:65%) and FTC (25/139, mean age 39.2 ± 14.3 years, M: F: 24%:76%). Average primary tumor size was 23.4 ± 11.1 mm and 26.5 ± 13.1 mm for PTC and FTC respectively (p value=0.223). Nodal metastasis was found more common in PTC than FTC (49% vs 28%, p value <0.05), whereas overall distant metastasis was approximately the same (13% and 24%, p value =0.277); however, bone metastasis was significantly higher in FTC than PTC (24% vs 5%, p value <0.05). Cumulative risk for nodal and distant metastases for FTC and PTC starts at PTS <20 mm and may indicate an unusual aggressive tumor behavior in the studied population. Highest cumulative risk for nodal and pulmonary metastases in PTC and for bone metastasis in FTC was found to be ≥ 50 mm PTS. We conclude that a PTS of <20 mm may indicate an unusual aggressive tumor behavior with highest cumulative risk for nodal and pulmonary metastases in PTC and for bone metastasis in FTC with a cutoff of ≥ 50 mm.
What is the incidence of isolated paraaortic nodal recurrence in grade 1 endometrial carcinoma?
Abu-Rustum, Nadeem R; Chi, Dennis S; Leitao, Mario; Oke, Eniola A; Hensley, Martee L; Alektiar, Kaled M; Barakat, Richard R
2008-10-01
To describe the incidence of isolated paraaortic nodal recurrences in patients with a final diagnosis of grade 1 endometrial carcinoma initially treated with surgery. Records from a prospectively maintained endometrial carcinoma database were reviewed to identify sites of recurrence. Patients with any papillary serous or clear cell carcinoma, leiomyosarcoma, endometrial stromal sarcoma, squamous carcinoma, or adenosarcoma were excluded. Recurrence sites were classified into 4 main categories: 1) pelvic (including vaginal and other soft tissue pelvic sites); 2) abdominal (including peritoneum, omentum and liver); 3) distant (including lung, brain, supraclavicular, and groins); and 4) isolated paraaortic nodal recurrence (including any nodal recurrence between the midcommon iliac to renal vessels). Between 1/93 and 5/06, 1453 patients with endometrial carcinoma met the study inclusion criteria. Final grade distribution included: grade 1 endometrial adenocarcinoma, 310 (21%); grade 2, 578 (40%); grade 3, 481 (33%); and incomplete, 84 (5.8%). In all, 154 patients (11%) had documented recurrences. Recurrence sites for all patients/all grades included: pelvis, 52 (34%); abdomen, 51 (33%); distant, 41 (27%), and isolated paraaortic, 10 (6%). None of the isolated paraaortic recurrences occurred in patients with a final diagnosis of grade 1 carcinoma. Furthermore, 9/10 (90%) isolated paraaortic nodal recurrences were in grade 3 tumors. Only 8 (2.6%) of 310 patients with grade 1 tumors recurred. Sites of recurrence for grade 1 tumors included: abdomen, 3; pelvis, 3; and distant, 2. This large series of endometrial carcinoma patients initially treated with surgery confirms that isolated paraaortic nodal recurrence in women with a final diagnosis of grade 1 endometrial carcinoma is extremely rare. These rare isolated paraaortic nodal recurrences appear to be limited to high-grade endometrial carcinomas.
Pentheroudakis, George; Stoyianni, Aikaterini; Pavlidis, Nicholas
2011-04-01
Midline nodal cancer of unknown primary (CUP) has varying definitions and an unclear natural history compared to that of extragonadal germ cell cancer (EGCC) and neuroendocrine tumors. We systematically reviewed all published series of patients with midline nodal CUP using three distinct definitions and presented our own retrospective cohort. Sixty four fit patients (median age 64) with poorly differentiated carcinoma or adenocarcinoma in midline nodal areas were treated from 1998 to 2008 at our center. Only two patients had elevated serum germ cell markers. Forty-eight percentage of patients responded to platinum-based chemotherapy (CR 11%). The median survival was 12 months (2-year survival 18%). Good PS (Hazard Ratio HR 0.287, p=0.058) and administration of platinum (HR 0.340, p=0.08) predicted for more favourable outcome. A subgroup of 15 male patients selected with stricter criteria had a CR rate of 33% and median survival of 18 months (2-year survival 24%). We identified 10 series of midline nodal CUP patients defined with discordant criteria. Despite high response rates (35-65%) to platinum chemotherapy, the median survival clustered around 12 months. Predictive factors for superior survival were low tumor bulk, patient fitness, female gender, carcinomatous histology, and absence of visceral metastases. There were differences between midline nodal CUP patients and EGCC as well as neuroendocrine tumors (age, tumor markers, response to therapy, long-term survival). Midline nodal CUP patients are poorly defined, fare less well than EGCC or neuroendocrine cancer and probably constitute a heterogeneous entity with a minority harbouring atypical germ cell cancer. Copyright © 2010 Elsevier Ltd. All rights reserved.
Moss-Lourenco, Patricia; Fields, Lanny
2011-01-01
Three experiments used postclass formation within-class preference test performances to evaluate the effects of nodal distance on the relatedness of stimuli in equivalence classes. In Experiment 1, two 2-node four-member equivalence classes were established using the simultaneous protocol in which all of the baseline relations were trained together, after which all emergent relations probes were presented together. All training and testing was done using match-to-sample trials that contained two comparisons. After class formation, the effects of nodal distance were evaluated using within-class preference tests that contained samples and both comparisons from the same class. These tests yielded inconsistent performances for most participants. Experiment 2 replicated Experiment 1, but a third null comparison was used on all trials during class formation. Thereafter, virtually all of the within-class probes, for all participants, evoked performances that were consistent with the predicted effects of nodal distance, that is, the selection of comparisons that were nodally closer to the samples. It appears, then, that the establishment of the equivalence classes with a third null comparison induced control by nodal structure of the classes. Experiment 3 demonstrated the generality of these findings with larger classes that contained more nodal separations, that is, three-node five-member classes. Emergent-relations tests conducted immediately after the within-class tests showed the classes to be intact. Thus, the differential relatedness of stimuli in a class or their interchangeability depended on the content of a test trial: within-class probes occasioned responding indicative of differential strength among the stimuli in the class, while cross-class tests occasioned responding indicative of interchangeability of stimuli in the same class. PMID:21547071
A predictive index of axillary nodal involvement in operable breast cancer.
De Laurentiis, M.; Gallo, C.; De Placido, S.; Perrone, F.; Pettinato, G.; Petrella, G.; Carlomagno, C.; Panico, L.; Delrio, P.; Bianco, A. R.
1996-01-01
We investigated the association between pathological characteristics of primary breast cancer and degree of axillary nodal involvement and obtained a predictive index of the latter from the former. In 2076 cases, 17 histological features, including primary tumour and local invasion variables, were recorded. The whole sample was randomly split in a training (75% of cases) and a test sample. Simple and multiple correspondence analysis were used to select the variables to enter in a multinomial logit model to build an index predictive of the degree of nodal involvement. The response variable was axillary nodal status coded in four classes (N0, N1-3, N4-9, N > or = 10). The predictive index was then evaluated by testing goodness-of-fit and classification accuracy. Covariates significantly associated with nodal status were tumour size (P < 0.0001), tumour type (P < 0.0001), type of border (P = 0.048), multicentricity (P = 0.003), invasion of lymphatic and blood vessels (P < 0.0001) and nipple invasion (P = 0.006). Goodness-of-fit was validated by high concordance between observed and expected number of cases in each decile of predicted probability in both training and test samples. Classification accuracy analysis showed that true node-positive cases were well recognised (84.5%), but there was no clear distinction among the classes of node-positive cases. However, 10 year survival analysis showed a superimposible prognostic behaviour between predicted and observed nodal classes. Moreover, misclassified node-negative patients (i.e. those who are predicted positive) showed an outcome closer to patients with 1-3 metastatic nodes than to node-negative ones. In conclusion, the index cannot completely substitute for axillary node information, but it is a predictor of prognosis as accurate as nodal involvement and identifies a subgroup of node-negative patients with unfavourable prognosis. PMID:8630286
Margaryan, Naira V; Gilgur, Alina; Seftor, Elisabeth A; Purnell, Chad; Arva, Nicoleta C; Gosain, Arun K; Hendrix, Mary J C; Strizzi, Luigi
2016-03-22
Expression of Nodal, a Transforming Growth Factor-beta (TGF-β) related growth factor, is associated with aggressive melanoma. Nodal expression in adult dysplastic nevi may predict the development of aggressive melanoma in some patients. A subset of pediatric patients diagnosed with giant or large congenital melanocytic nevi (LCMN) has shown increased risk for development of melanoma. Here, we investigate whether Nodal expression can help identify the rare cases of LCMN that develop melanoma and shed light on why the majority of these patients do not. Immunohistochemistry (IHC) staining results show varying degree of Nodal expression in pediatric dysplastic nevi and LCMN. Moreover, median scores from Nodal IHC expression analysis were not significantly different between these two groups. Additionally, none of the LCMN patients in this study developed melanoma, regardless of Nodal IHC levels. Co-culture experiments revealed reduced tumor growth and lower levels of Nodal and its signaling molecules P-SMAD2 and P-ERK1/2 when melanoma cells were grown in vivo or in vitro with normal melanocytes. The same was observed in melanoma cells cultured with melanocyte conditioned media containing pigmented melanocyte derived melanosomes (MDM). Since MDM contain molecules capable of inactivating radical oxygen species, to investigate potential anti-oxidant effect of MDM on Nodal expression and signaling in melanoma, melanoma cells were treated with either N-acetyl-l-cysteine (NAC), a component of the anti-oxidant glutathione or synthetic melanin, which in addition to providing pigmentation can also exert free radical scavenging activity. Melanoma cells treated with NAC or synthetic melanin showed reduced levels of Nodal, P-SMAD2 and P-ERK1/2 compared to untreated melanoma cells. Thus, the potential role for Nodal in melanoma development in LCMN is less evident than in adult dysplastic nevi possibly due to melanocyte cross-talk in LCMN capable of offsetting or delaying the pro
Advanced Nodal P_{3}/SP_{3} Axial Transport Solvers for the MPACT 2D/1D Scheme
Stimpson, Shane G; Collins, Benjamin S
2015-01-01
As part of its initiative to provide multiphysics simulations of nuclear reactor cores, the Consortium for Advanced Simulation of Light Water Reactors (CASL) is developing the Virtual Environment for Reactor Applications Core Simulator (VERA-CS). The MPACT code, which is the primary neutron transport solver of VERA-CS, employs the two-dimensional/one-dimensional (2D/1D) method to solve 3-dimensional neutron transport problems and provide sub-pin-level resolution of the power distribution. While 2D method of characteristics is used to solve for the transport effects within each plane, 1D-nodal methods are used axially. There have been extensive studies of the 2D/1D method with a variety nodal methods, and the P_{3}/SP_{3} solver has proved to be an effective method of providing higher-fidelity solutions while maintaining a low computational burden.The current implementation in MPACT wraps a one-node nodal expansion method (NEM) kernel for each moment, iterating between them and performing multiple sweeps to resolve flux distributions. However, it has been observed that this approach is more sensitive to convergence problems. This paper documents the theory and application two new nodal P_{3}/SP_{3} approaches to be used within the 2D/1D method in MPACT. These two approaches aim to provide enhanced stability compared with the pre-existing one-node approach. Results from the HY-NEM-SP_{3} solver show that the accuracy is consistent with the one-node formulations and provides improved convergence for some problems; but the solver has issues with cases in thin planes. Although the 2N-SENM-SP_{3} solver is still under development, it is intended to resolve the issues with HY-NEM-SP_{3} but it will incur some additional computational burden by necessitating an additional 1D-CMFD-P_{3} solver to generate the second moment cell-averaged scalar flux.
Audits of radiopharmaceutical formulations
Castronovo, F.P. Jr. )
1992-03-01
A procedure for auditing radiopharmaceutical formulations is described. To meet FDA guidelines regarding the quality of radiopharmaceuticals, institutional radioactive drug research committees perform audits when such drugs are formulated away from an institutional pharmacy. All principal investigators who formulate drugs outside institutional pharmacies must pass these audits before they can obtain a radiopharmaceutical investigation permit. The audit team meets with the individual who performs the formulation at the site of drug preparation to verify that drug formulations meet identity, strength, quality, and purity standards; are uniform and reproducible; and are sterile and pyrogen free. This team must contain an expert knowledgeable in the preparation of radioactive drugs; a radiopharmacist is the most qualified person for this role. Problems that have been identified by audits include lack of sterility and apyrogenicity testing, formulations that are open to the laboratory environment, failure to use pharmaceutical-grade chemicals, inadequate quality control methods or records, inadequate training of the person preparing the drug, and improper unit dose preparation. Investigational radiopharmaceutical formulations, including nonradiolabeled drugs, must be audited before they are administered to humans. A properly trained pharmacist should be a member of the audit team.
ANS shell elements with improved transverse shear accuracy. [Assumed Natural Coordinate Strain
NASA Technical Reports Server (NTRS)
Jensen, Daniel D.; Park, K. C.
1992-01-01
A method of forming assumed natural coordinate strain (ANS) plate and shell elements is presented. The ANS method uses equilibrium based constraints and kinematic constraints to eliminate hierarchical degrees of freedom which results in lower order elements with improved stress recovery and displacement convergence. These techniques make it possible to easily implement the element into the standard finite element software structure, and a modified shape function matrix can be used to create consistent nodal loads.
On bistable phasing of 18.6 year nodal induced flood in India
NASA Astrophysics Data System (ADS)
Currie, Robert G.
1984-01-01
In agreement with Campbell (1983), Flood Area Indices (FAI) for India are interpreted as being modulated by tidal forcing at the 18.6 yr lunar nodal period. There is evidence maximum flood was approximately out of phase with nodal epoch 1898.9 whereas at epochs 1917.5, 1936,1, 1954.7, and 1973.3 maximum flood was approximately in phase. This interpretation implies that India should be experiencing widespread dryness in an interval ±2 to 3 years centered at mid-epoch 1982.6.
Nodal superconductivity in FeS: Evidence from quasiparticle heat transport
NASA Astrophysics Data System (ADS)
Ying, T. P.; Lai, X. F.; Hong, X. C.; Xu, Y.; He, L. P.; Zhang, J.; Wang, M. X.; Yu, Y. J.; Huang, F. Q.; Li, S. Y.
2016-09-01
We report low-temperature heat transport measurements on superconducting iron sulfide FeS with Tc≈5 K, which has the same crystal structure and similar electronic band structure to the superconducting iron selenide FeSe. In zero magnetic field, a significant residual linear term κ0/T is observed. At low field, κ0/T increases rapidly with increasing field. These results suggest a nodal superconducting gap in FeS. We compare it with the sister compound FeSe and other iron-based superconductors with nodal gaps.
Weyl and Nodal Ring Magnons in Three-Dimensional Honeycomb Lattices
NASA Astrophysics Data System (ADS)
Li, Kang-Kang; Hu, Jiang-Ping
2017-07-01
We study the topological properties of magnon excitations in a wide class of three dimensional (3D) honeycomb lattices with ferromagnetic ground states. It is found that they host nodal ring magnon excitations. These rings locate on the same plane in the momentum space. The rings can be gapped by Dzyaloshinskii-Moriya (DM) interactions to form two Weyl points with opposite charges. We explicitly discuss these physics in the simplest 3D honeycomb lattice, the hyperhoneycomb lattice and show drumhead and arc surface states in the nodal ring and Weyl phases, respectively, due to the bulk-boundary correspondence.
Quasiparticle interference and resonant states in normal and superconducting line nodal semimetals
NASA Astrophysics Data System (ADS)
Setty, Chandan; Phillips, Philip W.; Narayan, Awadhesh
2017-04-01
We study impurity scattering in the normal and d -wave superconducting states of line nodal semimetals and show that, due to additional scattering phase space available for impurities on the surface, the quasiparticle interference pattern acquires an extended character instead of a discrete collection of delta function peaks. Moreover, using the T -matrix formalism, we demonstrate that the conventional behavior of a scalar impurity in a d -wave superconductor breaks down on the surface of a line nodal semimetal in the quasi-flat-band limit.
Riou, O; Bourgier, C; Fenoglietto, P; Azria, D
2015-06-01
Treatment volume is a major risk factor of radiation-induced toxicity. As nodal irradiation increases treatment volume, radiation toxicity should be greater. Nevertheless, scientific randomised data do not support this fact. However, a radiation-induced toxicity is possible outside tangential fields in the nodal volumes not related to breast-only treatment. Treatment should not be adapted only to the disease but personalized to the individual risk of toxicity for each patient. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.
Theoretical and Experimental Evidence for a Nodal Energy Gap in MgB2
2017-02-17
1 Theoretical and Experimental Evidence for a Nodal Energy Gap in MgB2 Y. Dan Agassia and Daniel E. Oatesb aConsultant, Jerusalem, Israel bMIT...the smaller of the two energy gaps in MgB2, the so-called gap, contains nodal lines with a six-fold symmetry (i-wave). The model also indicates that...in MgB2 and the Coulomb repulsion. It is based on a phononic pairing mechanism and assumes no coupling between the two energy gaps in MgB2 at zero
Numerical study of bipolar coordinate Jeffery-Hamel flow
NASA Astrophysics Data System (ADS)
Matyas, Alpar; Nagy, Botond
2017-07-01
In this paper we report the bipolar coordinate formulation of Jeffery-Hamel (JH) flow and study vorticity-stream function, bipolar coordinate JH and conventional JH solutions. It is shown that our derived equation can intrinsically describe the flow behavior in curved geometries and it gives improved results as compared to conventional JH theory.
Reactive decontamination formulation
Giletto, Anthony; White, William; Cisar, Alan J.; Hitchens, G. Duncan; Fyffe, James
2003-05-27
The present invention provides a universal decontamination formulation and method for detoxifying chemical warfare agents (CWA's) and biological warfare agents (BWA's) without producing any toxic by-products, as well as, decontaminating surfaces that have come into contact with these agents. The formulation includes a sorbent material or gel, a peroxide source, a peroxide activator, and a compound containing a mixture of KHSO.sub.5, KHSO.sub.4 and K.sub.2 SO.sub.4. The formulation is self-decontaminating and once dried can easily be wiped from the surface being decontaminated. A method for decontaminating a surface exposed to chemical or biological agents is also disclosed.
Formulation techniques for nanofluids.
Rivera-Solorio, Carlos I; Payán-Rodríguez, Luis A; García-Cuéllar, Alejandro J; Ramón-Raygoza, E D; L Cadena-de-la-Peña, Natalia; Medina-Carreón, David
2013-11-01
Fluids with suspended nanoparticles, commonly known as nanofluids, may be formulated to improve the thermal performance of industrial heat transfer systems and applications. Nanofluids may show enhanced thermal and electrical properties such as thermal conductivity, viscosity, heat transfer coefficient, dielectric strength, etc. However, stability problems may arise as nanoparticles usually have the tendency to agglomerate and sediment producing deterioration in the increment of these properties. In this review, we discuss patents that report advances in the formulation of nanofluids including: production methods, selection of components (nanoparticles, base fluid and surfactants), their chemical compositions and morphologies, and characterization techniques. Finally, current and future directions in the development of nanofluid formulation are discussed.
Topological crystalline materials: General formulation, module structure, and wallpaper groups
NASA Astrophysics Data System (ADS)
Shiozaki, Ken; Sato, Masatoshi; Gomi, Kiyonori
2017-06-01
We formulate topological crystalline materials on the basis of the twisted equivariant K theory. Basic ideas of the twisted equivariant K theory are explained with application to topological phases protected by crystalline symmetries in mind, and systematic methods of topological classification for crystalline materials are presented. Our formulation is applicable to bulk gapful topological crystalline insulators/superconductors and their gapless boundary and defect states, as well as bulk gapless topological materials such as Weyl and Dirac semimetals, and nodal superconductors. As an application of our formulation, we present a complete classification of topological crystalline surface states, in the absence of time-reversal invariance. The classification works for gapless surface states of three-dimensional insulators, as well as full gapped two-dimensional insulators. Such surface states and two-dimensional insulators are classified in a unified way by 17 wallpaper groups, together with the presence or the absence of (sublattice) chiral symmetry. We identify the topological numbers and their representations under the wallpaper group operation. We also exemplify the usefulness of our formulation in the classification of bulk gapless phases. We present a class of Weyl semimetals and Weyl superconductors that are topologically protected by inversion symmetry.
Nodal Quasiparticle Meltdown in Ultra-High Resolution Pump-Probe Angle-Resolved Photoemission
Graf, Jeff; Jozwiak, Chris; Smallwood, Chris L.; Eisaki, H.; Kaindl, Robert A.; Lee, Dung-Hai; Lanzara, Alessandra
2011-06-03
High-T{sub c} cuprate superconductors are characterized by a strong momentum-dependent anisotropy between the low energy excitations along the Brillouin zone diagonal (nodal direction) and those along the Brillouin zone face (antinodal direction). Most obvious is the d-wave superconducting gap, with the largest magnitude found in the antinodal direction and no gap in the nodal direction. Additionally, while antin- odal quasiparticle excitations appear only below T{sub c}, superconductivity is thought to be indifferent to nodal excitations as they are regarded robust and insensitive to T{sub c}. Here we reveal an unexpected tie between nodal quasiparticles and superconductivity using high resolution time- and angle-resolved photoemission on optimally doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} . We observe a suppression of the nodal quasiparticle spectral weight following pump laser excitation and measure its recovery dynamics. This suppression is dramatically enhanced in the superconducting state. These results reduce the nodal-antinodal dichotomy and challenge the conventional view of nodal excitation neutrality in superconductivity. The electronic structures of high-Tc cuprates are strongly momentum-dependent. This is one reason why the momentum-resolved technique of angle-resolved photoemission spectroscopy (ARPES) has been a central tool in the field of high-temperature superconductivity. For example, coherent low energy excitations with momenta near the Brillouin zone face, or antinodal quasiparticles (QPs), are only observed below T{sub c} and have been linked to superfluid density. They have therefore been the primary focus of ARPES studies. In contrast, nodal QPs, with momenta along the Brillouin zone diagonal, have received less attention and are usually regarded as largely immune to the superconducting transition because they seem insensitive to perturbations such as disorder, doping, isotope exchange, charge ordering, and temperature. Clearly
Minimal formulation of joint motion for biomechanisms
Seth, Ajay; Sherman, Michael; Eastman, Peter; Delp, Scott
2010-01-01
Biomechanical systems share many properties with mechanically engineered systems, and researchers have successfully employed mechanical engineering simulation software to investigate the mechanical behavior of diverse biological mechanisms, ranging from biomolecules to human joints. Unlike their man-made counterparts, however, biomechanisms rarely exhibit the simple, uncoupled, pure-axial motion that is engineered into mechanical joints such as sliders, pins, and ball-and-socket joints. Current mechanical modeling software based on internal-coordinate multibody dynamics can formulate engineered joints directly in minimal coordinates, but requires additional coordinates restricted by constraints to model more complex motions. This approach can be inefficient, inaccurate, and difficult for biomechanists to customize. Since complex motion is the rule rather than the exception in biomechanisms, the benefits of minimal coordinate modeling are not fully realized in biomedical research. Here we introduce a practical implementation for empirically-defined internal-coordinate joints, which we call “mobilizers.” A mobilizer encapsulates the observations, measurement frame, and modeling requirements into a hinge specification of the permissible-motion manifold for a minimal set of internal coordinates. Mobilizers support nonlinear mappings that are mathematically equivalent to constraint manifolds but have the advantages of fewer coordinates, no constraints, and exact representation of the biomechanical motion-space—the benefits long enjoyed for internal-coordinate models of mechanical joints. Hinge matrices within the mobilizer are easily specified by user-supplied functions, and provide a direct means of mapping permissible motion derived from empirical data. We present computational results showing substantial performance and accuracy gains for mobilizers versus equivalent joints implemented with constraints. Examples of mobilizers for joints from human biomechanics
Kimura, Tomoki; Togami, Taro; Nishiyama, Yoshihiro; Ohkawa, Motoomi; Takashima, Hitoshi
2010-06-01
Purpose: To evaluate the incidental irradiation dose to elective nodal regions in the treatment of advanced non-small-cell lung cancer with involved-field radiation therapy (IF-RT) and the pattern of elective nodal failure (ENF). Methods and Materials: Fifty patients with advanced non-small-cell lung cancer, who received IF-RT at Kagawa University were enrolled. To evaluate the dose of incidental irradiation, we delineated nodal regions with a Japanese map and the American Thoracic Society map (levels 1-11) in each patient retrospectively and calculated the dose parameters such as mean dose, D95, and V95 (40 Gy as the prescribed dose of elective nodal irradiation). Results: Using the Japanese map, the median mean dose was more than 40 Gy in most of the nodal regions, except at levels 1, 3, and 7. In particular, each dosimetric parameter of level 1 was significantly lower than those at other levels, and each dosimetric parameter of levels 10 to 11 ipsilateral (11I) was significantly higher than those in other nodal regions. Using the American Thoracic Society map, basically, the results were similar to those of the Japanese map. ENF was observed in 4 patients (8%), five nodal regions, and no mean dose to the nodal region exceeded 40 Gy. On the Japanese map, each parameter of these five nodal region was significantly lower than those of the other nodal regions. Conclusions: These results show that a high dose of incidental irradiation may contribute to the low incidence of ENF in patients who have received IF-RT.
Synthesis of planar five-connected nodal ligands.
Oms, Olivier; Jarrosson, Thibaut; Tong, Lok H; Vaccaro, Andrea; Bernardinelli, Gérald; Williams, Alan F
2009-01-01
Synthetic routes to a penta(4-pyridyl)cyclopentadienyl ligand are explored. The most successful route uses a palladium-catalysed pentapyridation of di(tert-butyl)phosphinoferrocene by using a procedure developed by Hartwig. The same method allows the synthesis of cyclopentadiene ligands substituted with 4-benzaldehydes or 4-phenylthiols. The pyridine ligands are formally five-connected nodes that may be linked by linear coordination metals to give closed spherical complexes of composition [(metal)(30)(ligand)(12)] as shown by molecular modelling. Experiment shows that the ligand complexes copper(I) and silver(I) with the expected 1:2.5 stoichiometry, and the (1)H NMR spectrum of the resulting product shows the ligands to be equivalent. NMR diffusion and light-scattering measurements support the formation of a species with a hydrodynamic radius of the order of 15 A, in agreement with the modelling studies. The resulting complex would be topologically identical to the C(60) fullerene structure.
Performance of mixed formulations for the particle finite element method in soil mechanics problems
NASA Astrophysics Data System (ADS)
Monforte, Lluís; Carbonell, Josep Maria; Arroyo, Marcos; Gens, Antonio
2016-11-01
This paper presents a computational framework for the numerical analysis of fluid-saturated porous media at large strains. The proposal relies, on one hand, on the particle finite element method (PFEM), known for its capability to tackle large deformations and rapid changing boundaries, and, on the other hand, on constitutive descriptions well established in current geotechnical analyses (Darcy's law; Modified Cam Clay; Houlsby hyperelasticity). An important feature of this kind of problem is that incompressibility may arise either from undrained conditions or as a consequence of material behaviour; incompressibility may lead to volumetric locking of the low-order elements that are typically used in PFEM. In this work, two different three-field mixed formulations for the coupled hydromechanical problem are presented, in which either the effective pressure or the Jacobian are considered as nodal variables, in addition to the solid skeleton displacement and water pressure. Additionally, several mixed formulations are described for the simplified single-phase problem due to its formal similitude to the poromechanical case and its relevance in geotechnics, since it may approximate the saturated soil behaviour under undrained conditions. In order to use equal-order interpolants in displacements and scalar fields, stabilization techniques are used in the mass conservation equation of the biphasic medium and in the rest of scalar equations. Finally, all mixed formulations are assessed in some benchmark problems and their performances are compared. It is found that mixed formulations that have the Jacobian as a nodal variable perform better.
Performance of mixed formulations for the particle finite element method in soil mechanics problems
NASA Astrophysics Data System (ADS)
Monforte, Lluís; Carbonell, Josep Maria; Arroyo, Marcos; Gens, Antonio
2017-07-01
This paper presents a computational framework for the numerical analysis of fluid-saturated porous media at large strains. The proposal relies, on one hand, on the particle finite element method (PFEM), known for its capability to tackle large deformations and rapid changing boundaries, and, on the other hand, on constitutive descriptions well established in current geotechnical analyses (Darcy's law; Modified Cam Clay; Houlsby hyperelasticity). An important feature of this kind of problem is that incompressibility may arise either from undrained conditions or as a consequence of material behaviour; incompressibility may lead to volumetric locking of the low-order elements that are typically used in PFEM. In this work, two different three-field mixed formulations for the coupled hydromechanical problem are presented, in which either the effective pressure or the Jacobian are considered as nodal variables, in addition to the solid skeleton displacement and water pressure. Additionally, several mixed formulations are described for the simplified single-phase problem due to its formal similitude to the poromechanical case and its relevance in geotechnics, since it may approximate the saturated soil behaviour under undrained conditions. In order to use equal-order interpolants in displacements and scalar fields, stabilization techniques are used in the mass conservation equation of the biphasic medium and in the rest of scalar equations. Finally, all mixed formulations are assessed in some benchmark problems and their performances are compared. It is found that mixed formulations that have the Jacobian as a nodal variable perform better.
The 18.6 yr nodal cycle and its impact on tidal sedimentation
NASA Astrophysics Data System (ADS)
Oost, A. P.; de Haas, H.; Ijnsen, F.; van den Boogert, J. M.; de Boer, P. L.
1993-09-01
The 18.6 yr nodal cycle modulates tidal amplitudes and currents, and consequently sedimentation in tide-influenced sedimentary environments. Data are presented which show that such effects are obvious along the coast of the Dutch barrier islands and in the sedimentary fill of abandoned channels.
Lin, Pan; Yang, Yong; Jovicich, Jorge; De Pisapia, Nicola; Wang, Xiang; Zuo, Chun S; Levitt, James Jonathan
2016-03-01
Characterization of the default mode network (DMN) as a complex network of functionally interacting dynamic systems has received great interest for the study of DMN neural mechanisms. In particular, understanding the relationship of intrinsic resting-state DMN brain network with cognitive behaviors is an important issue in healthy cognition and mental disorders. However, it is still unclear how DMN functional connectivity links to cognitive behaviors during resting-state. In this study, we hypothesize that static and dynamic DMN nodal topology is associated with upcoming cognitive task performance. We used graph theory analysis in order to understand better the relationship between the DMN functional connectivity and cognitive behavior during resting-state and task performance. Nodal degree of the DMN was calculated as a metric of network topology. We found that the static and dynamic posterior cingulate cortex (PCC) nodal degree within the DMN was associated with task performance (Reaction Time). Our results show that the core node PCC nodal degree within the DMN was significantly correlated with reaction time, which suggests that the PCC plays a key role in supporting cognitive function.
Minimizing the caliber of myelinated axons by means of nodal constrictions
Johnson, Christopher; Holmes, William R.; Brown, Anthony
2015-01-01
In myelinated axons, most of the voltage-gated ion channels are concentrated at the nodes of Ranvier, which are short gaps in the myelin sheath. This arrangement leads to saltatory conduction and a larger conduction velocity than in nonmyelinated axons. Intriguingly, axons in the peripheral nervous system that exceed about 2 μm in diameter exhibit a characteristic narrowing of the axon at nodes that results in a local reduction of the axonal cross-sectional area. The extent of constriction increases with increasing internodal axonal caliber, reaching a threefold reduction in diameter for the largest axons. In this paper, we use computational modeling to investigate the effect of nodal constrictions on axonal conduction velocity. For a fixed number of ion channels, we find that there is an optimal extent of nodal constriction which minimizes the internodal axon caliber that is required to achieve a given target conduction velocity, and we show that this is sensitive to the precise geometry of the axon and myelin sheath in the flanking paranodal regions. Thus axonal constrictions at nodes of Ranvier appear to be a biological adaptation to minimize axonal volume, thereby maximizing the spatial and metabolic efficiency of these processes, which can be a significant evolutionary constraint. We show that the optimal nodal morphologies are relatively insensitive to changes in the number of nodal sodium channels. PMID:26224772
Theory of nodal s ± -wave pairing symmetry in the Pu-based 115 superconductor family.
Das, Tanmoy; Zhu, Jian-Xin; Graf, Matthias J
2015-02-27
The spin-fluctuation mechanism of superconductivity usually results in the presence of gapless or nodal quasiparticle states in the excitation spectrum. Nodal quasiparticle states are well established in copper-oxide, and heavy-fermion superconductors, but not in iron-based superconductors. Here, we study the pairing symmetry and mechanism of a new class of plutonium-based high-Tc superconductors and predict the presence of a nodal s(±) wave pairing symmetry in this family. Starting from a density-functional theory (DFT) based electronic structure calculation we predict several three-dimensional (3D) Fermi surfaces in this 115 superconductor family. We identify the dominant Fermi surface "hot-spots" in the inter-band scattering channel, which are aligned along the wavevector Q = (π, π, π), where degeneracy could induce sign-reversal of the pairing symmetry. Our calculation demonstrates that the s(±) wave pairing strength is stronger than the previously thought d-wave pairing; and more importantly, this pairing state allows for the existence of nodal quasiparticles. Finally, we predict the shape of the momentum- and energy-dependent magnetic resonance spectrum for the identification of this pairing symmetry.
ERIC Educational Resources Information Center
Moss-Lourenco, Patricia; Fields, Lanny
2011-01-01
Three experiments used postclass formation within-class preference test performances to evaluate the effects of nodal distance on the relatedness of stimuli in equivalence classes. In Experiment 1, two 2-node four-member equivalence classes were established using the simultaneous protocol in which all of the baseline relations were trained…
Coexistence of topological nodal lines, Weyl points, and triply degenerate points in TaS
NASA Astrophysics Data System (ADS)
Sun, Jian-Peng; Zhang, Dong; Chang, Kai
2017-07-01
We theoretically propose that the single-crystal formed TaS is a new type of topological metal, hosting ring-shaped gapless nodal lines and triply degenerate points (TDPs) in the absence of spin-orbit coupling (SOC). In the presence of SOC, each TDP splits into four TDPs along the high-symmetric line in momentum space, and one of the nodal rings remains closed due to the protection of the mirror reflection symmetry, while another nodal ring is fully gapped and transforms into six pairs of Weyl points (WPs) carrying opposite chirality. The electronic structures of the projected surfaces are also discussed, the unique Fermi arcs are observed, and the chirality remains or vanishes depending on the projection directions. On the (010) projected surface, one may observe a Lifshitz transition. The new type of topological metal TaS is stable and experimentally achievable, and the coexistence of topological nodal lines, WPs, and TDPs in TaS makes it a potential candidate to study the interplay between different types of topological fermions.
NASA Astrophysics Data System (ADS)
Grootendorst, Diederik J.; Fratila, Raluca M.; Visscher, Martijn; Ten Haken, Bennie; van Wezel, Richard; Steenbergen, Wiendelt; Manohar, Srirang; Ruers, Theo J. M.
2013-02-01
Detection of tumor metastases in the lymphatic system is essential for accurate staging of various malignancies, however fast, accurate and cost-effective intra-operative evaluation of the nodal status remains difficult to perform with common available medical imaging techniques. In recent years, numerous studies have confirmed the additional value of superparamagnetic iron oxide dispersions (SPIOs) for nodal staging purposes, prompting the clearance of different SPIO dispersions for clinical practice. We evaluate whether a combination of photoacoustic (PA) imaging and a clinically approved SPIO dispersion, could be applied for intra-operative nodal staging. Metastatic adenocarcinoma was inoculated in Copenhagen rats for 5 or 8 days. After SPIO injection, the lymph nodes were photoacoustically imaged both in vivo and ex vivo whereafter imaging results were correlated with MR and histology. Results were compared to a control group without tumor inoculation. In the tumor groups clear irregularities, as small as 1 mm, were observed in the PA contrast pattern of the nodes together with an decrease of PA response. These irregularities could be correlated to the absence of contrast in the MR images and could be linked to metastatic deposits seen in the histological slides. The PA and MR images of the control animals did not show these features. We conclude that the combination of photoacoustic imaging with a clinically approved iron oxide nanoparticle dispersion is able to detect lymph node metastases in an animal model. This approach opens up new possibilities for fast intra-operative nodal staging in a clinical setting.
Targeting melanoma with front-line therapy does not abrogate Nodal-expressing tumor cells.
Hendrix, Mary Jc; Kandela, Irawati; Mazar, Andrew P; Seftor, Elisabeth A; Seftor, Richard Eb; Margaryan, Naira V; Strizzi, Luigi; Murphy, George F; Long, Georgina V; Scolyer, Richard A
2017-02-01
Metastatic melanoma is a highly aggressive skin cancer with a poor prognosis. It is the leading cause of skin cancer deaths with a median overall survival for advanced-stage metastatic disease of <6 months. Despite advances in the field with conventional and targeted therapies, the heterogeneity of melanoma poses the greatest ongoing challenge, ultimately leading to relapse and progression to a more drug-resistant tumor in most patients. Particularly noteworthy are recent findings, indicating that these therapies exert selective pressure on tumors resulting in the activation of pathways associated with cancer stem cells that are unresponsive to current therapy. Our previous studies have shown how Nodal, an embryonic morphogen of the transforming growth factor-beta superfamily, is one of these critical factors that is reactivated in aggressive melanoma and resistant to conventional chemotherapy, such as dacarbazine. In the current study, we sought to determine whether BRAF inhibitor (BRAFi) therapy targeted Nodal-expressing tumor cells in uniquely matched unresectable stage III and IV melanoma patient samples before and after therapy that preceded their eventual death due to disease. The results demonstrate that BRAFi treatment failed to affect Nodal levels in melanoma tissues. Accompanying experiments in soft agar and in nude mice showed the advantage of using combinatorial treatment with BRAFi plus anti-Nodal monoclonal antibody to suppress tumor growth and metastasis. These data provide a promising new approach using front-line therapy combined with targeting a cancer stem cell-associated molecule-producing a more efficacious response than monotherapy.
Prevalence and distribution pattern of nodal metastases in advanced ovarian cancer
Bachmann, Cornelia; Bachmann, Robert; Kraemer, Bernhard; Brucker, Sara Yvonne; Staebler, Anette; Fend, Falko; Rothmund, Ralf; Wallwiener, Diethelm
2016-01-01
The objective of this study was to examine the relevance of pelvic and para-aortic lymph node involvement and the tumour characteristics affecting nodal metastases and survival in primary advanced ovarian cancer. A total of 130 consecutive patients were retrospectively investigated. All the patients received stage-related surgery with pelvic and para-aortic lymphadenectomy. The median follow-up was 53.5 months. The clinicopathological parameters and distribution pattern of nodal metastases were evaluated. Lymph node metastases were detectable in 74.62% of the cases. Overall, both pelvic and para-aortic nodes were affected in 35.9% of the patients, whereas 13.3% had metastases only in the pelvic and 13.3% only in the para-aortic lymph nodes. Histological grade 1/2 and 3, serous and endometrioid histology were independent predictors of nodal metastasis. Serous and endometrioid cancers have shown a predilection for metastasis to the pelvic lymph nodes alone, both to the pelvic and the para-aortic nodes, or the para-aortic nodes alone. Overall survival was significantly positively affected by serous histology with positive nodes (P=0.043). It is crucial to investigate the risk factors and metastatic patterns of such patients in a multicenter analysis to evaluate individual subgroups. Prospective studies are required to investigate the prognostic effect of lymphadenectomy in advanced ovarian cancer and its association with histology and distribution pattern of nodal metastasis. PMID:27703680
Cervical nodal metastases in squamous cell carcinoma of the head and neck: what to expect.
Mukherji, S K; Armao, D; Joshi, V M
2001-11-01
The treatment and management of malignancies of the head and neck is directly altered by the presence of metastatic cervical adenopathy. The treatment of nodal metastases in squamous cell carcinoma of the head and neck (HNSCCA) is determined by the lymphatic drainage of the upper aerodigestive tract. The lymphatic drainage is site-specific and occurs in a predictable manner. The purpose of this text is to provide an overview of the normal routes of lymphatic drainage in the head and neck and correlate this with the current nodal classification system. The specific aims of this manuscript are to 1) illustrate the expected lymphatic drainage patterns of HNSCCA arising in the different subsites (nasopharynx, oropharynx, oral cavity, larynx, and hypopharynx) and 2) review the expected frequency of metastases within nodal groups for HNSCCA that arise in these locations. An understanding of the topographical distribution and incidence of cervical lymph node metastases plays an integral role in the physical examination and radiological evaluation of patients with HNSCCA. For the neuroradiologist, this information may increases the ability to identify those nodal groups at risk for metastatic involvement. Copyright 2001 John Wiley & Sons, Inc. Head Neck 23: 995-1005, 2001.
Nodal-line entanglement entropy: Generalized Widom formula from entanglement Hamiltonians
NASA Astrophysics Data System (ADS)
Pretko, Michael
2017-06-01
A system of fermions forming a Fermi surface exhibits a large degree of quantum entanglement, even in the absence of interactions. In particular, the usual case of a codimension one Fermi surface leads to a logarithmic violation of the area law for entanglement entropy as dictated by the Widom formula. We here generalize this formula to the case of arbitrary codimension, which is of particular interest for nodal lines in three dimensions. We first re-derive the standard Widom formula by calculating an entanglement Hamiltonian for Fermi-surface systems, obtained by repurposing a trick commonly applied to relativistic theories. The entanglement Hamiltonian will take a local form in terms of a low-energy patch theory for the Fermi surface, although it is nonlocal with respect to the microscopic fermions. This entanglement Hamiltonian can then be used to derive the entanglement entropy, yielding a result in agreement with the Widom formula. The method is then generalized to arbitrary codimension. For nodal lines, the area law is obeyed, and the magnitude of the coefficient for a particular partition is nonuniversal. However, the coefficient has a universal dependence on the shape and orientation of the nodal line relative to the partitioning surface. By comparing the relative magnitude of the area law for different partitioning cuts, entanglement entropy can be used as a tool for diagnosing the presence and shape of a nodal line in a ground-state wave function.
Nodal surface approximations to the P, G, D and I-WP triply periodic minimal surfaces
NASA Astrophysics Data System (ADS)
Gandy, Paul J. F.; Bardhan, Sonny; Mackay, Alan L.; Klinowski, Jacek
2001-03-01
The cubic P, G, D and I-WP triply periodic minimal surfaces (TPMS) may be closely approximated using periodic nodal surfaces (PNS) with few Fourier terms, thus enabling easy generation of TPMS for use in various chemical and physical applications. The accuracy of such approximations is quantitatively discussed and represented visually using a colour coding.
Anomalous nodal count and singularities in the dispersion relation of honeycomb graphs
NASA Astrophysics Data System (ADS)
Band, Ram; Berkolaiko, Gregory; Weyand, Tracy
2015-12-01
We study the nodal count of the so-called bi-dendral graphs and show that it exhibits an anomaly: the nodal surplus is never equal to 0 or β, the first Betti number of the graph. According to the nodal-magnetic theorem, this means that bands of the magnetic spectrum (dispersion relation) of such graphs do not have maxima or minima at the "usual" symmetry points of the fundamental domain of the reciprocal space of magnetic parameters. In search of the missing extrema, we prove a necessary condition for a smooth critical point to happen inside the reciprocal fundamental domain. Using this condition, we identify the extrema as the singularities in the dispersion relation of the maximal Abelian cover of the graph (the honeycomb graph being an important example). In particular, our results show that the anomalous nodal count is an indication of the presence of conical points in the dispersion relation of the maximal universal cover. We also discover that the conical points are present in the dispersion relation of graphs with much less symmetry than was required in previous investigations.
A.A. Bingham; R.M. Ferrer; A.M. ougouag
2009-09-01
An accurate and computationally efficient two or three-dimensional neutron diffusion model will be necessary for the development, safety parameters computation, and fuel cycle analysis of a prismatic Very High Temperature Reactor (VHTR) design under Next Generation Nuclear Plant Project (NGNP). For this purpose, an analytical nodal Green’s function solution for the transverse integrated neutron diffusion equation is developed in two and three-dimensional hexagonal geometry. This scheme is incorporated into HEXPEDITE, a code first developed by Fitzpatrick and Ougouag. HEXPEDITE neglects non-physical discontinuity terms that arise in the transverse leakage due to the transverse integration procedure application to hexagonal geometry and cannot account for the effects of burnable poisons across nodal boundaries. The test code being developed for this document accounts for these terms by maintaining an inventory of neutrons by using the nodal balance equation as a constraint of the neutron flux equation. The method developed in this report is intended to restore neutron conservation and increase the accuracy of the code by adding these terms to the transverse integrated flux solution and applying the nodal Green’s function solution to the resulting equation to derive a semi-analytical solution.
Precision evaluation of lens systems using a nodal slide/MTF optical bench
NASA Astrophysics Data System (ADS)
Doherty, Victor J.; Chapnik, Philip D.
1992-01-01
A compact, self-contained production instrument designed to permit the rapid and precise performance characterization of a wide variety of lenses and optical systems has been developed by Eidolon Corporation. The Eidolon Production Nodal Slide/MTF Measurement System can be used to measure effective focal length (EFL), distortion, field curvature, chromatic aberration, spot size, and modulation transfer function (MTF).
New nonlinear iterative scheme for the analytic function expansion nodal method
Moon, Kap Suk; Noh, Jae Man; Cho, Nam Zin
1997-12-01
The nonlinear scheme has turned out to be very effective computing time, and in minimizing memory requirements, computing time, and implementing effort associated with higher order nodal methods. This scheme solves the modified finite difference method (FDM) current equation given for the interface of nodes n and n + 1 with side-length h.
A Developmentally Based Categorization of Branching in Trifolium repens L.: Influence of Nodal Roots
THOMAS, R. G.; HAY, M. J. M.; NEWTON, P. C. D.
2002-01-01
This study describes the successive stages of development of branches from axillary buds in fully rooted plants of Trifolium repens grown in near optimal conditions, and the way in which this developmental pathway differs when nodal root formation is prevented as plants grow out from a rooted base. Cuttings of a single genotype were established in a glasshouse with nodal root systems on the two basal phytomers and grown on so that nodal rooting was either permitted (+R) or prevented (–R). In +R plants, axillary tissues could be assigned to one of four developmental categories: unemerged buds, emerged buds, unbranched lateral branches or secondarily branched lateral branches. In –R plants, branch development was retarded, with the retardation becoming increasingly pronounced as the number of –R phytomers on the primary stolon increased. Retarded elongation of the internodes of lateral shoots on –R plants resulted in the formation of a distinct fifth developmental category: short shoots (defined as branches with two or more leaves but with mean internode length equal to, or less than, 10 % of that of the immediately proximal internode on the parent stolon) which had reduced phytomer appearance rates but retained the potential to develop into lateral branches. Transfer of +R plants to –R conditions, and vice versa, after 66 d demonstrated that subsequent branch development was wholly under the control of the youngest nodal root present, regardless of the age and number of root systems proximal to it. PMID:12234150
ERIC Educational Resources Information Center
Chatzarakis, G. E.
2009-01-01
This paper presents a new pedagogical method for nodal analysis optimization based on the use of virtual current sources, applicable to any linear electric circuit (LEC), regardless of its complexity. The proposed method leads to straightforward solutions, mostly arrived at by inspection. Furthermore, the method is easily adapted to computer…
ERIC Educational Resources Information Center
Chatzarakis, G. E.
2009-01-01
This paper presents a new pedagogical method for nodal analysis optimization based on the use of virtual current sources, applicable to any linear electric circuit (LEC), regardless of its complexity. The proposed method leads to straightforward solutions, mostly arrived at by inspection. Furthermore, the method is easily adapted to computer…
Bohora, Shomu; Singh, Parvindar; Shah, Kaushal
2016-01-01
A 58 year old gentleman with complaints of palpitations and documented tachycardia was found to have a dilated right atrium, right ventricle and coronary sinus, which were due to partial unroofed coronary sinus without a left superior vena cava. He had upper septal ventricular tachycardia and atrio-ventricular nodal reentrant tachycardia, which was successfully treated by radiofrequency ablation. PMID:25852246
Bud emergence and shoot growth from mature citrus nodal stem segments
USDA-ARS?s Scientific Manuscript database
Bud emergence and shoot growth from adult phase citrus nodal cultures were studied using Citrus mitis (calamondin), Citrus paradisi (grapefruit), and Citrus sinensis (sweet orange). The effects of 6-benzylaminopurine (BA), indole 3-acetic acid (IAA), and citrus type on shoot quality and growth fro...
Analysis of nodal aberration properties in off-axis freeform system design.
Shi, Haodong; Jiang, Huilin; Zhang, Xin; Wang, Chao; Liu, Tao
2016-08-20
Freeform surfaces have the advantage of balancing off-axis aberration. In this paper, based on the framework of nodal aberration theory (NAT) applied to the coaxial system, the third-order astigmatism and coma wave aberration expressions of an off-axis system with Zernike polynomial surfaces are derived. The relationship between the off-axis and surface shape acting on the nodal distributions is revealed. The nodal aberration properties of the off-axis freeform system are analyzed and validated by using full-field displays (FFDs). It has been demonstrated that adding Zernike terms, up to nine, to the off-axis system modifies the nodal locations, but the field dependence of the third-order aberration does not change. On this basis, an off-axis two-mirror freeform system with 500 mm effective focal length (EFL) and 300 mm entrance pupil diameter (EPD) working in long-wave infrared is designed. The field constant aberrations induced by surface tilting are corrected by selecting specific Zernike terms. The design results show that the nodes of third-order astigmatism and coma move back into the field of view (FOV). The modulation transfer function (MTF) curves are above 0.4 at 20 line pairs per millimeter (lp/mm) which meets the infrared reconnaissance requirement. This work provides essential insight and guidance for aberration correction in off-axis freeform system design.
Mammographic Density and Prediction of Nodal Status in Breast Cancer Patients
Hack, C. C.; Häberle, L.; Geisler, K.; Schulz-Wendtland, R.; Hartmann, A.; Fasching, P. A.; Uder, M.; Wachter, D. L.; Jud, S. M.; Loehberg, C. R.; Lux, M. P.; Rauh, C.; Beckmann, M. W.; Heusinger, K.
2013-01-01
Aim: Nodal status remains one of the most important prognostic factors in breast cancer. The cellular and molecular reasons for the spread of tumor cells to the lymph nodes are not well understood and there are only few predictors in addition to tumor size and multifocality that give an insight into additional mechanisms of lymphatic spread. Aim of our study was therefore to investigate whether breast characteristics such as mammographic density (MD) add to the predictive value of the presence of lymph node metastases in patients with primary breast cancer. Methods: In this retrospective study we analyzed primary, metastasis-free breast cancer patients from one breast center for whom data on MD and staging information were available. A total of 1831 patients were included into this study. MD was assessed as percentage MD (PMD) using a semiautomated method and two readers for every patient. Multiple logistic regression analyses with nodal status as outcome were used to investigate the predictive value of PMD in addition to age, tumor size, Ki-67, estrogen receptor (ER), progesterone receptor (PR), grading, histology, and multi-focality. Results: Multifocality, tumor size, Ki-67 and grading were relevant predictors for nodal status. Adding PMD to a prediction model which included these factors did not significantly improve the prediction of nodal status (p = 0.24, likelihood ratio test). Conclusion: Nodal status could be predicted quite well with the factors multifocality, tumor size, Ki-67 and grading. PMD does not seem to play a role in the lymphatic spread of tumor cells. It could be concluded that the amount of extracellular matrix and stromal cell content of the breast which is reflected by MD does not influence the probability of malignant breast cells spreading from the primary tumor to the lymph nodes. PMID:24771910
An approach to model reactor core nodalization for deterministic safety analysis
NASA Astrophysics Data System (ADS)
Salim, Mohd Faiz; Samsudin, Mohd Rafie; Mamat @ Ibrahim, Mohd Rizal; Roslan, Ridha; Sadri, Abd Aziz; Farid, Mohd Fairus Abd
2016-01-01
Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH1.6, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D® computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.
Combined-modality therapy for patients with regional nodal metastases from melanoma
Ballo, Matthew T. . E-mail: mballo@mdanderson.org; Ross, Merrick I.; Cormier, Janice N.; Myers, Jeffrey N.; Lee, Jeffrey E.; Gershenwald, Jeffrey E.; Hwu, Patrick; Zagars, Gunar K.
2006-01-01
Purpose: To evaluate the outcome and patterns of failure for patients with nodal metastases from melanoma treated with combined-modality therapy. Methods and Materials: Between 1983 and 2003, 466 patients with nodal metastases from melanoma were managed with lymphadenectomy and radiation, with or without systemic therapy. Surgery was a therapeutic procedure for clinically apparent nodal disease in 434 patients (regionally advanced nodal disease). Adjuvant radiation was generally delivered with a hypofractionated regimen. Adjuvant systemic therapy was delivered to 154 patients. Results: With a median follow-up of 4.2 years, 252 patients relapsed and 203 patients died of progressive disease. The actuarial 5-year disease-specific, disease-free, and distant metastasis-free survival rates were 49%, 42%, and 44%, respectively. By multivariate analysis, increasing number of involved lymph nodes and primary ulceration were associated with an inferior 5-year actuarial disease-specific and distant metastasis-free survival. Also, the number of involved lymph nodes was associated with the development of brain metastases, whereas thickness was associated with lung metastases, and primary ulceration was associated with liver metastases. The actuarial 5-year regional (in-basin) control rate for all patients was 89%, and on multivariate analysis there were no patient or disease characteristics associated with inferior regional control. The risk of lymphedema was highest for those patients with groin lymph node metastases. Conclusions: Although regional nodal disease can be satisfactorily controlled with lymphadenectomy and radiation, the risk of distant metastases and melanoma death remains high. A management approach to these patients that accounts for the competing risks of distant metastases, regional failure, and long-term toxicity is needed.
Noh, O Kyu; Lee, Sang-wook; Yoon, Sang Min; Kim, Sung Bae; Kim, Sang Yoon; Kim, Chang Jin; Jo, Kyung Ja; Choi, Eun Kyung; Song, Si Yeol; Kim, Jong Hoon; Ahn, Seung Do
2011-02-01
Purpose: The role of elective nodal irradiation (ENI) in radiotherapy for esthesioneuroblastoma (ENB) has not been clearly defined. We analyzed treatment outcomes of patients with ENB and the frequency of cervical nodal failure in the absence of ENI. Methods and Materials: Between August 1996 and December 2007, we consulted with 19 patients with ENB regarding radiotherapy. Initial treatment consisted of surgery alone in 2 patients; surgery and postoperative radiotherapy in 4; surgery and adjuvant chemotherapy in 1; surgery, postoperative radiotherapy, and chemotherapy in 3; and chemotherapy followed by radiotherapy or concurrent chemoradiotherapy in 5. Five patients did not receive planned radiotherapy because of disease progression. Including 2 patients who received salvage radiotherapy, 14 patients were treated with radiotherapy. Elective nodal irradiation was performed in 4 patients with high-risk factors, including 3 with cervical lymph node metastasis at presentation. Results: Fourteen patients were analyzable, with a median follow-up of 27 months (range, 7-64 months). The overall 3-year survival rate was 73.4%. Local failure occurred in 3 patients (21.4%), regional cervical failure in 3 (21.4%), and distant failure in 2 (14.3%). No cervical nodal failure occurred in patients treated with combined systemic chemotherapy regardless of ENI. Three cervical failures occurred in the 4 patients treated with ENI or neck dissection (75%), none of whom received systemic chemotherapy. Conclusions: ENI during radiotherapy for ENB seems to play a limited role in preventing cervical nodal failure. Omitting ENI may be an option if patients are treated with a combination of radiotherapy and chemotherapy.
Correlation effects and quantum oscillations in topological nodal-loop semimetals
NASA Astrophysics Data System (ADS)
Liu, Jianpeng; Balents, Leon
2017-02-01
We study the unique physical properties of topological nodal-loop semimetals protected by the coexistence of time-reversal and inversion symmetries with negligible spin-orbit coupling. We argue that strong correlation effects occur at the surface of such systems for relatively small Hubbard interaction U , due to the narrow bandwidth of the "drumhead" surface states. In the Hartree-Fock approximation, at small U we obtain a surface ferromagnetic phase through a continuous quantum phase transition characterized by the surface-mode divergence of the spin susceptibility, while the bulk states remain very robust against local interactions and remain nonordered. At slightly increased interaction strength, the system quickly changes from a surface ferromagnetic phase to a surface charge-ordered phase through a first-order transition. When Rashba-type spin-orbit coupling is applied to the surface states, a canted ferromagnetic phase occurs at the surface for intermediate values of U . The quantum critical behavior of the surface ferromagnetic transition is nontrivial in the sense that the surface spin order parameter couples to Fermi-surface excitations from both surface and bulk states. This leads to unconventional Landau damping and consequently a naïve dynamical critical exponent z ≈1 when the Fermi level is close to the bulk nodal energy. We also show that, already without interactions, quantum oscillations arise due to bulk states, despite the absence of a Fermi surface when the chemical potential is tuned to the energy of the nodal loop. The bulk magnetic susceptibility diverges logarithmically whenever the nodal loop exactly overlaps with a quantized magnetic orbit in the bulk Brillouin zone. These correlation and transport phenomena are unique signatures of nodal-loop states.
ARPES Study of Nodal Quasiparticles Using Low-Energy Tunable Photons
NASA Astrophysics Data System (ADS)
Ino, Akihiro
2006-03-01
Low-energy quasiparticle excitations govern the thermodynamic properties of a superconductor both in the zero-field and vortex-mixed states. For a d-wave superconductor, nodal quasiparticles are crucial excitations starting from zero energy. So far, however, the nodal quasiparticle dynamics of high-Tc cuprates has been controversial. For example, it has been reported by an angle-resolved-photoemission (ARPES) experiment that the marginal-Fermi-liquid behavior persists into the superconducting state without appreciable change in the scattering rate, while microwave conductivity increases upon the superconducting transition. Here, we show a new ARPES result that solves the controversies with unprecedented momentum-resolution. Low-energy tunable photons have enabled us to resolve a small nodal bilayer splitting clearly, and to reveal the detailed temperature- and energy-dependence of the scattering rate, indicating the behaviors unique to the nodal quasiparticles. Due to the opening of the d-wave gap, the nodal scattering rate is remarkably suppressed, and shows a linear energy dependence. The difference in the energy-linear term between the bilayer-resolved scattering rates hints the nature of impurities involved. This work was done in collaboration with T. Yamasaki, T. Kamo, K. Yamazaki, H. Anzai, M. Arita, H. Namatame, M. Taniguchi, Grad. Sch. of Science and Hiroshima Synchrotron Radiation Center, Hiroshima Univ., A. Fujimori, Dept. of Complexity Science and Engineering, Univ. of Tokyo, Z.-X. Shen, Dept. of Physics, Applied Physics and SSRL, Stanford Univ., M. Ishikado, K. Fujita, and S. Uchida, Dept. of Physics, Univ. of Tokyo.
An approach to model reactor core nodalization for deterministic safety analysis
Salim, Mohd Faiz Samsudin, Mohd Rafie; Mamat Ibrahim, Mohd Rizal; Roslan, Ridha Sadri, Abd Aziz; Farid, Mohd Fairus Abd
2016-01-22
Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH{sub 1.6}, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D{sup ®} computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.
The impact of nodal tumour burden on lymphoscintigraphic imaging in patients with melanomas.
Kretschmer, Lutz; Bertsch, Hans Peter; Bardzik, Pawel; Meller, Johannes; Hellriegel, Simin; Thoms, Kai-Martin; Schön, Michael Peter; Sahlmann, Carsten Oliver
2015-02-01
To retrospectively study the influence of nodal tumour burden on lymphoscintigraphic imaging in 509 consecutive patients with melanomas. Bidirectional lymphatic drainage, the clear depiction of an afferent lymphatic vessel, time to depiction of the first sentinel lymph node (SLN) and number of depicted and excised nodes were recorded. Nodal tumour load was classified as SLN-negative, SLN micrometastases or macrometastases. In the overall population, using multivariate regression analysis, a short SLN depiction time was significantly associated with the depiction of a greater number of radioactive nodes, a short distance between the primary tumour site and the nodal basin, younger age and lower nodal tumour burden. The proportion of patients with clear depiction of an afferent lymphatic vessel depended on the nodal tumour load (46% in SLN-negative patients, 57% in SLN positive patients, and 69% in patients with macrometastases; P = 0.009). Macrometastasis was significantly associated with delayed depiction of the first radioactive node and a greater number of depicted hotspots. In patients with clinically nonsuspicious nodes, i.e. the classical target group for SLN biopsy, clear depiction of an afferent vessel was significantly associated with a higher number of SLNs during dynamic acquisition, SLN micrometastasis and a higher overall number of metastatic lymph nodes after SLN biopsy plus completion lymphadenectomy. The excision of more than two SLNs did not increase the metastasis detection rate. In patients with bidirectional or tridirectional lymphatic drainage, the SLN positivity rates for the first, second and third basin were 25.4%, 11.7% and 0.0 %, respectively (P = 0.002). In patients with clinically nonsuspicious lymph nodes, clear depiction of an afferent lymph vessel may be a sign of micrometastasis. Macrometastasis is associated with prominent afferent vessels, delayed depiction of the first radioactive node and a higher number of depicted
Formulations and nebulizer performance.
O'Riordan, Thomas G
2002-11-01
To deliver a drug by nebulization, the drug must first be dispersed in a liquid (usually aqueous) medium. After application of a dispersing force (either a jet of gas or ultrasonic waves), the drug particles are contained within the aerosol droplets, which are then inhaled. Some drugs readily dissolve in water, whereas others need a cosolvent such as ethanol or propylene glycol. Some drugs are delivered as suspensions, and the efficiency of nebulizers can be different for solutions and suspensions. Solutions are delivered more efficiently with most devices. In general, conventional ultrasonic nebulizers should not be used to aerosolize suspensions, because of low efficiency. Newer strategies to improve the delivery of non-water-soluble drugs include the use of liposomes and the milling of the drug into very small "nanoparticles." In addition to the active therapeutic ingredient and solvents, drug formulations may include buffers (the solubility of some medications is influenced by pH), stabilizers, and, in the case of multi-dose preparations, antibacterial agents. Though formulations are designed to optimize drug solubility and stability, changes in formulation can also affect inhaled mass, particle size, and treatment time, though the differences between nebulizer brands probably have a greater impact than differences in formulation. Ultrasonic and jet nebulizers may damage protein and other complex agents through heat or shear stress. Additives to multi-dose formulations, especially antimicrobial and chelating agents, may cause adverse events, so there is a trend towards single-use, preservative-free vials.
Temporally coordinated signals progressively pattern the anteroposterior and dorsoventral body axes
Tuazon, Francesca B; Mullins, Mary C
2015-01-01
The vertebrate body plan is established through the precise spatiotemporal coordination morphogen signaling pathways that pattern the anteroposterior (AP) and dorsoventral (DV) axes. Patterning along the AP axis is directed by posteriorizing signals Wnt, fibroblast growth factor (FGF), Nodal, and retinoic acid (RA), while patterning along the DV axis is directed by bone morphogenetic proteins (BMP) ventralizing signals. This review addresses the current understanding of how Wnt, FGF, RA and BMP pattern distinct AP and DV cell fates during early development and how their signaling mechanisms are coordinated to concomitantly pattern AP and DV tissues. PMID:26123688
Granulated decontamination formulations
Tucker, Mark D.
2007-10-02
A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a sorbent additive, and water. A highly adsorbent sorbent additive (e.g., amorphous silica, sorbitol, mannitol, etc.) is used to "dry out" one or more liquid ingredients into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.
Sunscreen product formulation.
Tanner, Paul R
2006-01-01
On the surface, sunscreen products are pretty simple. They consist of a delivery vehicle containing one or more sunscreen active ingredients. When applied to the skin, these sunscreen actives intercept solar ultraviolet (UV) rays before they can damage the underlying skin. However, while conceptually simple, a detailed analysis reveals that sunscreen formulations are quite complex, requiring careful selection of sunscreen active and vehicle components to control multiple performance and in-use parameters.Thus, to enable a better understanding and appreciation of sunscreen products, the typical steps in formulating a sunscreen product are described. Throughout this process, the key is to apply scientific principles together with a bit of formulation art to holistically create the best sunscreen product that meets the design targets--a sunscreen product that people will use regularly and properly.
Wang, Wei
2015-01-01
It is well recognized that protein product development is far more challenging than that for small-molecule drugs. The major challenges include inherent sensitivity to different types of stresses during the drug product manufacturing process, high rate of physical and chemical degradation during long-term storage, and enhanced aggregation and/or viscosity at high protein concentrations. In the past decade, many novel formulation concepts and technologies have been or are being developed to address these product development challenges for proteins. These concepts and technologies include use of uncommon/combination of formulation stabilizers, conjugation or fusion with potential stabilizers, site-specific mutagenesis, and preparation of nontraditional types of dosage forms—semiaqueous solutions, nonfreeze-dried solid formulations, suspensions, and other emerging concepts. No one technology appears to be mature, ideal, and/or adequate to address all the challenges. These gaps will likely remain in the foreseeable future and need significant efforts for ultimate resolution. PMID:25858529
Lubrication in tablet formulations.
Wang, Jennifer; Wen, Hong; Desai, Divyakant
2010-05-01
Theoretical aspects and practical considerations of lubrication in tablet compression are reviewed in this paper. Properties of the materials that are often used as lubricants, such as magnesium stearate, in tablet dosage form are summarized. The manufacturing process factors that may affect tablet lubrication are discussed. As important as the lubricants in tablet formulations are, their presence can cause some changes to the tablet physical and chemical properties. Furthermore, a detailed review is provided on the methodologies used to characterize lubrication process during tablet compression with relevant process analytical technologies. Finally, the Quality-by-Design considerations for tablet formulation and process development in terms of lubrication are discussed.
Developmental coordination disorder
... with visual or fine motor coordination (for example, writing, using scissors, tying shoelaces, or tapping one finger ... take notes may help children who have trouble writing. Children with developmental coordination disorder are more likely ...
Belkacemi, Y; Kaidar-Person, O; Poortmans, P; Ozsahin, M; Valli, M-C; Russell, N; Kunkler, I; Hermans, J; Kuten, A; van Tienhoven, G; Westenberg, H
2015-03-01
Predicting outcome of breast cancer (BC) patients based on sentinel lymph node (SLN) status without axillary lymph node dissection (ALND) is an area of uncertainty. It influences the decision-making for regional nodal irradiation (RNI). The aim of the NORA (NOdal RAdiotherapy) survey was to examine the patterns of RNI. A web-questionnaire, including several clinical scenarios, was distributed to 88 EORTC-affiliated centers. Responses were received between July 2013 and January 2014. A total of 84 responses were analyzed. While three-dimensional (3D) radiotherapy (RT) planning is carried out in 81 (96%) centers, nodal areas are delineated in only 51 (61%) centers. Only 14 (17%) centers routinely link internal mammary chain (IMC) and supraclavicular node (SCN) RT indications. In patients undergoing total mastectomy (TM) with ALND, SCN-RT is recommend by 5 (6%), 53 (63%) and 51 (61%) centers for patients with pN0(i+), pN(mi) and pN1, respectively. Extra-capsular extension (ECE) is the main factor influencing decision-making RNI after breast conserving surgery (BCS) and TM. After primary systemic therapy (PST), 49 (58%) centers take into account nodal fibrotic changes in ypN0 patients for RNI indications. In ypN0 patients with inner/central tumors, 23 (27%) centers indicate SCN-RT and IMC-RT. In ypN1 patients, SCN-RT is delivered by less than half of the centers in patients with ypN(i+) and ypN(mi). Twenty-one (25%) of the centers recommend ALN-RT in patients with ypN(mi) or 1-2N+ after ALND. Seventy-five (90%) centers state that age is not considered a limiting factor for RNI. The NORA survey is unique in evaluating the impact of SLNB/ALND status on adjuvant RNI decision-making and volumes after BCS/TM with or without PST. ALN-RT is often indicated in pN1 patients, particularly in the case of ECE. Besides the ongoing NSABP-B51/RTOG and ALLIANCE trials, NORA could help to design future specific RNI trials in the SLNB era without ALND in patients receiving or not PST.
Röttinger, Eric; DuBuc, Timothy Q.; Amiel, Aldine R.; Martindale, Mark Q.
2015-01-01
ABSTRACT Nodal signaling plays crucial roles in vertebrate developmental processes such as endoderm and mesoderm formation, and axial patterning events along the anteroposterior, dorsoventral and left-right axes. In echinoderms, Nodal plays an essential role in the establishment of the dorsoventral axis and left-right asymmetry, but not in endoderm or mesoderm induction. In protostomes, Nodal signaling appears to be involved only in establishing left-right asymmetry. Hence, it is hypothesized that Nodal signaling has been co-opted to pattern the dorsoventral axis of deuterostomes and for endoderm, mesoderm formation as well as anteroposterior patterning in chordates. Hemichordata, together with echinoderms, represent the sister taxon to chordates. In this study, we analyze the role of Nodal signaling in the indirect developing hemichordate Ptychodera flava. In particular, we show that during gastrulation nodal transcripts are detected in a ring of cells at the vegetal pole that gives rise to endomesoderm and in the ventral ectoderm at later stages of development. Inhibition of Nodal function disrupts dorsoventral fates and also blocks formation of the larval mesoderm. Interestingly, molecular analysis reveals that only mesodermal, apical and ventral gene expression is affected while the dorsal side appears to be patterned correctly. Taken together, this study suggests that the co-option of Nodal signaling in mesoderm formation and potentially in anteroposterior patterning has occurred prior to the emergence of chordates and that Nodal signaling on the ventral side is uncoupled from BMP signaling on the dorsal side, representing a major difference from the molecular mechanisms of dorsoventral patterning events in echinoderms. PMID:25979707
Röttinger, Eric; DuBuc, Timothy Q; Amiel, Aldine R; Martindale, Mark Q
2015-05-15
Nodal signaling plays crucial roles in vertebrate developmental processes such as endoderm and mesoderm formation, and axial patterning events along the anteroposterior, dorsoventral and left-right axes. In echinoderms, Nodal plays an essential role in the establishment of the dorsoventral axis and left-right asymmetry, but not in endoderm or mesoderm induction. In protostomes, Nodal signaling appears to be involved only in establishing left-right asymmetry. Hence, it is hypothesized that Nodal signaling has been co-opted to pattern the dorsoventral axis of deuterostomes and for endoderm, mesoderm formation as well as anteroposterior patterning in chordates. Hemichordata, together with echinoderms, represent the sister taxon to chordates. In this study, we analyze the role of Nodal signaling in the indirect developing hemichordate Ptychodera flava. In particular, we show that during gastrulation nodal transcripts are detected in a ring of cells at the vegetal pole that gives rise to endomesoderm and in the ventral ectoderm at later stages of development. Inhibition of Nodal function disrupts dorsoventral fates and also blocks formation of the larval mesoderm. Interestingly, molecular analysis reveals that only mesodermal, apical and ventral gene expression is affected while the dorsal side appears to be patterned correctly. Taken together, this study suggests that the co-option of Nodal signaling in mesoderm formation and potentially in anteroposterior patterning has occurred prior to the emergence of chordates and that Nodal signaling on the ventral side is uncoupled from BMP signaling on the dorsal side, representing a major difference from the molecular mechanisms of dorsoventral patterning events in echinoderms.
Cognitive Personal Coordination Assistants
2005-03-01
of TÆMS [2, 7], DTC agent scheduling [16, 19, 12], GPGP agent coordination [2, 1, 6], and a similar approach to team coordination [17]. From the...a tactical TÆMS view, and how a Generalized Partial Global Planning ( GPGP ) coordination mechanism operates over the tactical views. Although we don’t...Norman Carver, Alan Garvey, Daniel Neiman, and Nagendra Prasad. Evolution of the GPGP Domain-Independent Coordination Framework. Computer Science
Opportunities in care coordination.
Meckes, Cathy S
2005-10-01
The growing incidence of chronic illness and the increase in the number of elderly individuals wishing to live in their own homes as long as possible have created opportunities for care coordination services. Home care providers are well positioned to take advantage of the need for care coordination. The developing nature of the market for these services means providers ready to offer care coordination can influence how care coordination services will be packaged, delivered, and funded.
Processing Coordination Ambiguity
ERIC Educational Resources Information Center
Engelhardt, Paul E.; Ferreira, Fernanda
2010-01-01
We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based…
Literacy Coordinators' Handbook.
ERIC Educational Resources Information Center
Department for Education and Skills, London (England).
This handbook is designed to provide support for England's National Literacy Strategy's Literacy Coordinators leading and coordinating literacy across the school. The handbook is designed as a working document and will contain additional materials, LEA (local education authorities) guidance, and additional papers which Coordinators may choose to…
NASA Technical Reports Server (NTRS)
Nothnagel, A.
2013-01-01
We present the IVS analysis coordination issues of 2012. The IVS Analysis Coordinator is responsible for generating and disseminating the official IVS products. This requires consistency of the input data by strict adherence to models and conventions. The term of the current IVS Analysis Coordinator will end on February 28, 2013.
Processing Coordination Ambiguity
ERIC Educational Resources Information Center
Engelhardt, Paul E.; Ferreira, Fernanda
2010-01-01
We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based…
Motté, G; Belhassen, B; Bodereau, P
1979-03-01
In a series of 48 patients undergoing electrophysiological investigation for attacks of reciprocating tachycardia related to concealed or overt Wolff-Parkinson-White syndrome in sinus rhythm, 4 patients were found to have duality of nodal conduction. This association was responsible for several tachycardia circuits: in 2 patients the activation passed constantly retrogradely through the accessory pathway and then either through the slow nodal pathway or the rapid nodal pathway in the anterograde direction. In the other two patients, in addition to classical orthodromic tachycardia, purely intranodal reciprocating rhythms giving rise to sustained tachycardia in one case and to simple echos in the other, were observed.
Garg, Sanjay; Tambwekar, Kaustubh R; Vermani, Kavita; Kandarapu, Raghupathi; Garg, Alka; Waller, Donald P; Zaneveld, Lourens J D
2003-08-01
In recent years, AIDS and sexually transmitted diseases (STDs) have become a burgeoning problem and are spreading at an alarming rate. Microbicides are being developed as a new therapeutic category for prevention of transmission of sexually transmitted infections (STIs) and HIV. Many of the microbicide formulations (MF) may fail to elicit a protective response either because of a lack of efficacy or inadequate formulation. Manufacturing a stable, efficacious, safe, and optimal product is the main objective of formulation development programs. Preformulation parameters (PP), as discussed in Part I of this series, influence formulation development significantly and should be considered carefully before designing a formulation strategy. Initially, based on PP and market research, a target product profile (TPP) is generated, which defines product attributes that can be normally classified as "essential" and "desirable." A complex and dynamic process begins thereafter that takes into consideration myriad factors starting from selection of delivery system, selection of excipients, compatibility study, prototype composition, selection of process and optimization, stability testing, scale up, manufacturing under good manufacturing practices (GMP), and packaging development. Prototype formulations are evaluated for several performance characteristics (e.g., dispersion behavior, bioadhesion, retention, spreading, rheology). These compositions are also subjected to biologic evaluation by various in vitro and in vivo models. Such a well-planned, well-coordinated, and well-implemented formulation development program not only accelerates overall development but also minimizes failures in subsequent clinical development studies. The objective of this review is to highlight the importance of formulation science, outline the steps involved in this process, and explore how these can be exploited for achieving optimal MF.
New Variational Formulations of Hybrid Stress Elements
NASA Technical Reports Server (NTRS)
Pian, T. H. H.; Sumihara, K.; Kang, D.
1984-01-01
In the variational formulations of finite elements by the Hu-Washizu and Hellinger-Reissner principles the stress equilibrium condition is maintained by the inclusion of internal displacements which function as the Lagrange multipliers for the constraints. These versions permit the use of natural coordinates and the relaxation of the equilibrium conditions and render considerable improvements in the assumed stress hybrid elements. These include the derivation of invariant hybrid elements which possess the ideal qualities such as minimum sensitivity to geometric distortions, minimum number of independent stress parameters, rank sufficient, and ability to represent constant strain states and bending moments. Another application is the formulation of semiLoof thin shell elements which can yield excellent results for many severe test cases because the rigid body nodes, the momentless membrane strains, and the inextensional bending modes are all represented.
Scale Invariant Gravity - a Simple Formulation
NASA Astrophysics Data System (ADS)
Wesson, P. S.
1981-09-01
Using the Cosmological Principle as justification, it is suggested that the scale-invariant theory of gravity be based on a Conspiracy Hypothesis (CH). The CH says: The matter parameters of a system (mass, density, pressure, etc.), the "constants" of physics and the coordinates occur together in dimensionless combinations (η-numbers) in which the components may vary but in such a manner that the variations conspire to keep the -numbers constant. This hypothesis yields a formulation of the scale-invariant theory that is simpler than other versions of it in which the Newtonian gravitational parameter G is treated as a field variable (Dirac, Hoyle/Narlikar, Canuto et al.). This simple formulation of scale-invariant gravity agrees with a recent reformulation of the (Perfect) Cosmological Principle. It also agrees with observations that have been made to date, and the equations suggest several new tests that can possibly be carried out.
Formulation and application of Russell's method
NASA Technical Reports Server (NTRS)
Hou, J. W.
1985-01-01
It is shown that the numerical technique of Russell's momentum approach can be derived by using Hamilton's principle and Vance's numerical scheme. It results in a set of first order differnce equations for solving the angular velocities. The numerical examples show that the method is reliable. The algorithm is modified next to perform the analysis of N-body systems with closed loop topology. To increase the formulation flexibility, the equations of motion are represented by using Cartesian coordinates and Lagrange multipliers. The algorithm consists of two parts, Vance's scheme and an unconstrained minimization. The Vance's scheme is used to find the angular velocities, and the unconstrained minimization is applied to provide the correct angular displacements. The proposed scheme is further extended to find the design sensitivity of an N-body system with closed loop configuration, and to carry out the design optimization as well. The numerical example of a small-scaled mechanical system is presented to verify the proposed formulation.
Gauge-Invariant Formulation of Circular Dichroism.
Raimbault, Nathaniel; de Boeij, Paul L; Romaniello, Pina; Berger, J A
2016-07-12
Standard formulations of magnetic response properties, such as circular dichroism spectra, are plagued by gauge dependencies, which can lead to unphysical results. In this work, we present a general gauge-invariant and numerically efficient approach for the calculation of circular dichroism spectra from the current density. First we show that in this formulation the optical rotation tensor, the response function from which circular dichroism spectra can be obtained, is independent of the origin of the coordinate system. We then demonstrate that its trace is independent of the gauge origin of the vector potential. We also show how gauge invariance can be retained in practical calculations with finite basis sets. As an example, we explain how our method can be applied to time-dependent current-density-functional theory. Finally, we report gauge-invariant circular dichroism spectra obtained using the adiabatic local-density approximation. The circular dichroism spectra we thus obtain are in good agreement with experiment.
New Variational Formulations of Hybrid Stress Elements
NASA Technical Reports Server (NTRS)
Pian, T. H. H.; Sumihara, K.; Kang, D.
1984-01-01
In the variational formulations of finite elements by the Hu-Washizu and Hellinger-Reissner principles the stress equilibrium condition is maintained by the inclusion of internal displacements which function as the Lagrange multipliers for the constraints. These versions permit the use of natural coordinates and the relaxation of the equilibrium conditions and render considerable improvements in the assumed stress hybrid elements. These include the derivation of invariant hybrid elements which possess the ideal qualities such as minimum sensitivity to geometric distortions, minimum number of independent stress parameters, rank sufficient, and ability to represent constant strain states and bending moments. Another application is the formulation of semiLoof thin shell elements which can yield excellent results for many severe test cases because the rigid body nodes, the momentless membrane strains, and the inextensional bending modes are all represented.
Bochev, Pavel Blagoveston
2011-06-01
We develop a new formulation of the Control Volume Finite Element Method (CVFEM) with a multidimensional Scharfetter-Gummel (SG) upwinding for the drift-diffusion equations. The formulation uses standard nodal elements for the concentrations and expands the flux in terms of the lowest-order Nedelec H(curl; {Omega})-compatible finite element basis. The SG formula is applied to the edges of the elements to express the Nedelec element degree of freedom on this edge in terms of the nodal degrees of freedom associated with the endpoints of the edge. The resulting upwind flux incorporates the upwind effects from all edges and is defined at the interior of the element. This allows for accurate evaluation of integrals on the boundaries of the control volumes for arbitrary quadrilateral elements. The new formulation admits efficient implementation through a standard loop over the elements in the mesh followed by loops over the element nodes (associated with control volume fractions in the element) and element edges (associated with flux degrees of freedom). The quantities required for the SG formula can be precomputed and stored for each edge in the mesh for additional efficiency gains. For clarity the details are presented for two-dimensional quadrilateral grids. Extension to other element shapes and three dimensions is straightforward.
NASA Technical Reports Server (NTRS)
Yu, Jr-Kai; Holland, Linda Z.; Holland, Nicholas D.
2002-01-01
The full-length sequence and zygotic expression of an amphioxus nodal gene are described. Expression is first detected in the early gastrula just within the dorsal lip of the blastopore in a region of hypoblast that is probably comparable with the vertebrate Spemann's organizer. In the late gastrula and early neurula, expression remains bilaterally symmetrical, limited to paraxial mesoderm and immediately overlying regions of the neural plate. Later in the neurula stage, all neural expression disappears, and mesodermal expression disappears from the right side. All along the left side of the neurula, mesodermal expression spreads into the left side of the gut endoderm. Soon thereafter, all expression is down-regulated except near the anterior and posterior ends of the animal, where transcripts are still found in the mesoderm and endoderm on the left side. At this time, expression also begins in the ectoderm on the left side of the head, in the region where the mouth later forms. These results suggest that amphioxus and vertebrate nodal genes play evolutionarily conserved roles in establishing Spemann's organizer, patterning the mesoderm rostrocaudally and setting up the asymmetrical left-right axis of the body.
Huang, Wei; Huang, Yong; Sun, Jujie; Liu, Xibin; Zhang, Jian; Zhou, Tao; Zhang, Baijiang; Li, Baosheng
2015-07-01
To construct an anatomical atlas of thoracic lymph node regions of esophageal cancer (EC) based on definitions from The Japan Esophageal Society (JES) and generate a consensus to delineate the nodal clinical target volume (CTVn) for elective nodal radiation (ENI) of esophageal squamous cell carcinoma (ESCC). An interdisciplinary group including two dedicated radiation oncologists, an experienced radiologist, a pathologist and two thoracic surgeons were gathered to generate a three-dimensional radiological description for the mediastinal lymph node regions of EC on axial CT scans. Then the radiological boundaries of lymph node regions were validated by a relatively large number of physicians in multiple institutions. An atlas of detailed anatomic boundaries of lymph node station No. 105-114 was defined on axial CT, along with illustrations. From the previous work, the study provided a guide of CTVn contouring for ENI of thoracic ESCC from a single center. It is feasible to use such an atlas of thoracic lymph node stations for radiotherapy planning. A phase III study based on the atlas is ongoing in China to measure quantitatively the ENI received by patients with ESCC. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Hypervelocity, minimum-radii, coordinated turns
NASA Technical Reports Server (NTRS)
Tauber, Michael E.
1990-01-01
An analytic solution is presented for the most basic powered-flight maneuver, consisting of a constant-altitude coordinated turn and expressions for minimum-turn radii; associated flight conditions are derived. It is shown that the formulation for hypervelocity turns differs from that for subsonic and hypersonic speeds. Illustrative calculations using approximate aerodynamics based on Newtonian theory are presented, and these demonstrate the differences of hypersonic flight conditions and their associated turning radii from those at lower speeds.
Self-energy of a nodal fermion in a d -wave superconductor
NASA Astrophysics Data System (ADS)
Chubukov, A. V.; Tsvelik, A. M.
2006-06-01
We reconsider the self-energy of a nodal (Dirac) fermion in a two-dimensional d -wave superconductor. A conventional belief is that ImΣ(ω,T)˜max(ω3,T3) . We show that Σ(ω,k,T) for k along the nodal direction is actually a complex function of ω,T , and the deviation from the mass shell. In particular, the second-order self-energy diverges at a finite T when either ω or k-kF vanish. We show that the full summation of infinite diagrammatic series recovers a finite result for Σ , but the full angle-resolved photoemission spectroscopy spectral function is nonmonotonic and has a kink whose location compared to the mass shell differs qualitatively for spin-and charge-mediated interactions.
Final Trial Report of Sentinel-Node Biopsy versus Nodal Observation in Melanoma
Morton, D.L.; Thompson, J.F.; Cochran, A.J.; Mozzillo, N.; Nieweg, O.E.; Roses, D.F.; Hoekstra, H.J.; Karakousis, C.P.; Puleo, C.A.; Coventry, B.J.; Kashani-Sabet, M.; Smithers, B.M.; Paul, E.; Kraybill, W.G.; McKinnon, J.G.; Wang, H.-J.; Elashoff, R.; Faries, M.B.
2014-01-01
Background Sentinel-node biopsy, a minimally invasive procedure for regional melanoma staging, was evaluated in a phase 3 trial. Methods We evaluated outcomes in 2001 patients with primary cutaneous melanomas randomly assigned to undergo wide excision and nodal observation, with lymphadenectomy for nodal relapse (observation group), or wide excision and sentinel-node biopsy, with immediate lymphadenectomy for nodal metastases detected on biopsy (biopsy group). Results No significant treatment-related difference in the 10-year melanoma-specific survival rate was seen in the overall study population (20.8% with and 79.2% without nodal metastases). Mean (±SE) 10-year disease-free survival rates were significantly improved in the biopsy group, as compared with the observation group, among patients with intermediate-thickness melanomas, defined as 1.20 to 3.50 mm (71.3±1.8% vs. 64.7±2.3%; hazard ratio for recurrence or metastasis, 0.76; P = 0.01), and those with thick melanomas, defined as >3.50 mm (50.7±4.0% vs. 40.5±4.7%; hazard ratio, 0.70; P = 0.03). Among patients with intermediate-thickness melanomas, the 10-year melanoma-specific survival rate was 62.1±4.8% among those with metastasis versus 85.1±1.5% for those without metastasis (hazard ratio for death from melanoma, 3.09; P<0.001); among patients with thick melanomas, the respective rates were 48.0±7.0% and 64.6±4.9% (hazard ratio, 1.75; P = 0.03). Biopsy-based management improved the 10-year rate of distant disease–free survival (hazard ratio for distant metastasis, 0.62; P = 0.02) and the 10-year rate of melanoma-specific survival (hazard ratio for death from melanoma, 0.56; P = 0.006) for patients with intermediate-thickness melanomas and nodal metastases. Accelerated-failure-time latent-subgroup analysis was performed to account for the fact that nodal status was initially known only in the biopsy group, and a significant treatment benefit persisted. Conclusions Biopsy-based staging of
Weyl points and topological nodal superfluids in a face-centered-cubic optical lattice
NASA Astrophysics Data System (ADS)
Lang, Li-Jun; Zhang, Shao-Liang; Law, K. T.; Zhou, Qi
2017-07-01
We point out that a face-centered-cubic (fcc) optical lattice, which can be realized by a simple scheme using three lasers, provides one a highly controllable platform for creating Weyl points and topological nodal superfluids in ultracold atoms. In noninteracting systems, Weyl points automatically arise in the Floquet band structure when shaking such fcc lattices, and sophisticated design of the tunneling is not required. More interestingly, in the presence of attractive interaction between two hyperfine spin states, which experience the same shaken fcc lattice, a three-dimensional topological nodal superfluid emerges, and Weyl points show up as the gapless points in the quasiparticle spectrum. One could either create a double Weyl point of charge 2, or split it into two Weyl points of charge 1, which can be moved in the momentum space by tuning the interactions. Correspondingly, the Fermi arcs at the surface may be linked with each other or separated as individual ones.
NASA Technical Reports Server (NTRS)
Harvey, Jason; Moore, Michael
2013-01-01
The General-Use Nodal Network Solver (GUNNS) is a modeling software package that combines nodal analysis and the hydraulic-electric analogy to simulate fluid, electrical, and thermal flow systems. GUNNS is developed by L-3 Communications under the TS21 (Training Systems for the 21st Century) project for NASA Johnson Space Center (JSC), primarily for use in space vehicle training simulators at JSC. It has sufficient compactness and fidelity to model the fluid, electrical, and thermal aspects of space vehicles in real-time simulations running on commodity workstations, for vehicle crew and flight controller training. It has a reusable and flexible component and system design, and a Graphical User Interface (GUI), providing capability for rapid GUI-based simulator development, ease of maintenance, and associated cost savings. GUNNS is optimized for NASA's Trick simulation environment, but can be run independently of Trick.
The ancestral role of nodal signalling in breaking L/R symmetry in the vertebrate forebrain.
Lagadec, Ronan; Laguerre, Laurent; Menuet, Arnaud; Amara, Anis; Rocancourt, Claire; Péricard, Pierre; Godard, Benoît G; Rodicio, Maria Celina; Rodriguez-Moldes, Isabel; Mayeur, Hélène; Rougemont, Quentin; Mazan, Sylvie; Boutet, Agnès
2015-03-30
Left-right asymmetries in the epithalamic region of the brain are widespread across vertebrates, but their magnitude and laterality varies among species. Whether these differences reflect independent origins of forebrain asymmetries or taxa-specific diversifications of an ancient vertebrate feature remains unknown. Here we show that the catshark Scyliorhinus canicula and the lampreys Petromyzon marinus and Lampetra planeri exhibit conserved molecular asymmetries between the left and right developing habenulae. Long-term pharmacological treatments in these species show that nodal signalling is essential to their generation, rather than their directionality as in teleosts. Moreover, in contrast to zebrafish, habenular left-right differences are observed in the absence of overt asymmetry of the adjacent pineal field. These data support an ancient origin of epithalamic asymmetry, and suggest that a nodal-dependent asymmetry programme operated in the forebrain of ancestral vertebrates before evolving into a variable trait in bony fish.
NASA Astrophysics Data System (ADS)
Vorontsov, Anton; Vekhter, Ilya
2006-03-01
We present a calculation of electronic specific heat and heat conductivity in a vortex state of quasi-two dimensional d-wave superconductors. We employ quasiclassical theory and use the Brand-Pesch-Tewordt approximation to model the superconducting state at moderate to high magnetic fields. Within this framework we investigate the dependence of heat capacity and heat conductivity on the angle of rotation of magnetic field with respect to the nodal directions. We find that the fourfold anisotropy due to nodal structure in both quantities changes sign in the temperature-field plane. This result helps resolve the apparent disagreement about the gap symmetry reached from the specific heat and the thermal conductivity measurements in CeCoIn5. We comment on the physics behind the difference between our results and those obtained in the Doppler shift approximation.
The effect of viscosity on steady transonic flow with a nodal solution topology
NASA Technical Reports Server (NTRS)
Owocki, Stanley P.; Zank, Gary P.
1991-01-01
The effect of viscosity on a steady, transonic flow for which the inviscid limit has a nodal solution topology near the critical point is investigated. For the accelerating case, viscous solutions tend to repel each other, so that a very delicate choice of initial conditions is required to prevent them from diverging. Only the two critical solutions extend to arbitrarily large distances into both the subsonic and supersonic flows. For the decelerating case, the solutions tend to attract, and so an entire two-parameter family of solutions now extends over large distances. The general effect of viscosity on the solution degeneracy of a nodal topology is thus to reduce or limit it for the accelerating case and to enhance it for the decelerating case. The astrophysical implications of these findings are addressed.
Normal State Spectral Lineshapes of Nodal Quasiparticles in Single Layer Bi2201 Superconductor
Lanzara, A.
2010-04-30
A detailed study of the normal state photoemission lineshapes and quasiparticle dispersion for the single layer Bi{sub 2}Sr{sub 2-x}La{sub x}CuO{sub 6+{delta}}(Bi2201) superconductor is presented. We report the first experimental evidence of a double peak structure and a dip of spectral intensity in the energy distribution curves (EDCs) along the nodal direction. The double peak structure is well identified in the normal state, up to ten times the critical temperature. As a result of the same self-energy effect, a strong mass renormalization of the quasiparticle dispersion, i.e. kink, and an increase of the quasiparticle lifetime in the normal state are also observed. Our results provide unambiguous evidence on the existence of bosonic excitation in the normal state, and support a picture where nodal quasiparticles are strongly coupled to the lattice.
On the development of hierarchical solution strategies for nonlinear finite element formulations
NASA Technical Reports Server (NTRS)
Padovan, J.; Lackney, J.
1984-01-01
This paper develops a hierarchical type solution scheme which can handle the field equations associated with nonlinear finite element simulations. The overall procedure possesses various levels of application namely degree of freedom, nodal, elemental, substructural as well as global. In particular iteration, updating, assembly and solution control occurs at the various hierarchical levels. Due to the manner of formulation, the degree of matrix inversion depends on the size of the various hierarchical partitioned groups. In this context, degree of freedom partitioning requires no inversion. To benchmark the overall scheme, the results of several numerical examples are presented.
Akdeniz, Z. Istanbul Univ. . Dept. of Physics); Tosi, M.P. . Dipt. di Fisica Teorica Argonne National Lab., IL )
1988-11-01
The stability of local fourfold coordination for divalent and trivalent metal ions in liquid mixtures of polyvalent metal halides and alkali halides is classified by means of structural coordinates obtained from properties of the elements. In parallel with earlier classifications of compound crystal structures and molecular shapes, the elemental properties are taken from first-principles calculations of valence electron orbitals in atoms, in the form of (i) the nodal radii of Andreoni, Baldereschi and Guizzetti or (ii) the pseudopotential radii or Zunger and Cohen. As a third alternative a classification based on Pettifor's phenomenological chemical scale of the elements is also considered. The alternative structural classification schemes that are developed from these elemental properties are generally successfully in distinguishing molten mixtures in which the available experimental evidence indicates long-lived fourfold coordination of polyvalent metal ions. In addition, Pettifor's chemical scale scheme is useful in sorting out finer details of local coordination in the liquid state. 3 figs., 71 refs.
EXTENSION OF THE 1D FOUR-GROUP ANALYTIC NODAL METHOD TO FULL MULTIGROUP
B. D. Ganapol; D. W. Nigg
2008-09-01
In the mid 80’s, a four-group/two-region, entirely analytical 1D nodal benchmark appeared. It was readily acknowledged that this special case was as far as one could go in terms of group number and still achieve an analytical solution. In this work, we show that by decomposing the solution to the multigroup diffusion equation into homogeneous and particular solutions, extension to any number of groups is a relatively straightforward exercise using the mathematics of linear algebra.
NODAL in the Uterus Is Necessary for Proper Placental Development and Maintenance of Pregnancy1
Park, Craig B.; DeMayo, Francesco J.; Lydon, John P.; Dufort, Daniel
2012-01-01
Preterm birth is the single leading cause of perinatal mortality in developed countries, affecting approximately 12% of pregnancies and accounting for 75% of neonatal loss in the United States. Despite the prevalence and severity of premature delivery, the causes and mechanisms that underlie spontaneous and idiopathic preterm birth remain unknown. Our inability to elucidate these fundamental causes has been attributed to a poor understanding of the signaling pathways associated with the premature induction of parturition and a lack of suitable animal models available for preterm birth research. In this study, we describe the generation and analysis of a novel conditional knockout of the transforming growth factor beta (TGFB) superfamily member, Nodal, from the maternal reproductive tract of mice. Strikingly, uterine Nodal knockout females exhibited a severe malformation of the maternal decidua basalis during placentation, leading to significant intrauterine growth restriction, and ultimately preterm birth and fetal loss on Day 17.5 of gestation. Using several approaches, we characterized aberrant placental development and demonstrated that reduced proliferation combined with increased apoptosis resulted in a diminished decidua basalis and compromised maternal-fetal interface. Last, we evaluated various components of the established parturition cascade and determined that preterm birth derived from the maternal Nodal knockout occurs prior to PTGS2 (COX-2) upregulation at the placental interface. Taken together, the results presented in this study highlight an in vivo role for maternal NODAL during placentation, present an interesting link between disrupted decidua basalis formation and premature parturition, and describe a potentially valuable model toward elucidating the complex processes that underlie preterm birth. PMID:22378764
NODAL in the uterus is necessary for proper placental development and maintenance of pregnancy.
Park, Craig B; DeMayo, Francesco J; Lydon, John P; Dufort, Daniel
2012-06-01
Preterm birth is the single leading cause of perinatal mortality in developed countries, affecting approximately 12% of pregnancies and accounting for 75% of neonatal loss in the United States. Despite the prevalence and severity of premature delivery, the causes and mechanisms that underlie spontaneous and idiopathic preterm birth remain unknown. Our inability to elucidate these fundamental causes has been attributed to a poor understanding of the signaling pathways associated with the premature induction of parturition and a lack of suitable animal models available for preterm birth research. In this study, we describe the generation and analysis of a novel conditional knockout of the transforming growth factor beta (TGFB) superfamily member, Nodal, from the maternal reproductive tract of mice. Strikingly, uterine Nodal knockout females exhibited a severe malformation of the maternal decidua basalis during placentation, leading to significant intrauterine growth restriction, and ultimately preterm birth and fetal loss on Day 17.5 of gestation. Using several approaches, we characterized aberrant placental development and demonstrated that reduced proliferation combined with increased apoptosis resulted in a diminished decidua basalis and compromised maternal-fetal interface. Last, we evaluated various components of the established parturition cascade and determined that preterm birth derived from the maternal Nodal knockout occurs prior to PTGS2 (COX-2) upregulation at the placental interface. Taken together, the results presented in this study highlight an in vivo role for maternal NODAL during placentation, present an interesting link between disrupted decidua basalis formation and premature parturition, and describe a potentially valuable model toward elucidating the complex processes that underlie preterm birth.
Zhao Kuaile; Ma Jinbo; Liu Guang; Wu Kailiang; Shi Xuehui; Jiang Guoliang
2010-02-01
Purpose: To evaluate the local control, survival, and toxicity associated with three-dimensional conformal radiotherapy (3D-CRT) for squamous cell carcinoma (SCC) of the esophagus, to determine the appropriate target volumes, and to determine whether elective nodal irradiation is necessary in these patients. Methods and Materials: A prospective study of 3D-CRT was undertaken in patients with esophageal SCC without distant metastases. Patients received 68.4 Gy in 41 fractions over 44 days using late-course accelerated hyperfractionated 3D-CRT. Only the primary tumor and positive lymph nodes were irradiated. Isolated out-of-field regional nodal recurrence was defined as a recurrence in an initially uninvolved regional lymph node. Results: All 53 patients who made up the study population tolerated the irradiation well. No acute or late Grade 4 or 5 toxicity was observed. The median survival time was 30 months (95% confidence interval, 17.7-41.8). The overall survival rate at 1, 2, and 3 years was 77%, 56%, and 41%, respectively. The local control rate at 1, 2, and 3 years was 83%, 74%, and 62%, respectively. Thirty-nine of the 53 patients (74%) showed treatment failure. Seventeen of the 39 (44%) developed an in-field recurrence, 18 (46%) distant metastasis with or without regional failure, and 3 (8%) an isolated out-of-field nodal recurrence only. One patient died of disease in an unknown location. Conclusions: In patients treated with 3D-CRT for esophageal SCC, the omission of elective nodal irradiation was not associated with a significant amount of failure in lymph node regions not included in the planning target volume. Local failure and distant metastases remained the predominant problems.
Tumour thickness predicts cervical nodal metastases and survival in early oral tongue cancer.
O-charoenrat, P; Pillai, G; Patel, S; Fisher, C; Archer, D; Eccles, S; Rhys-Evans, P
2003-06-01
Squamous cell carcinoma (SCC) of the oral tongue is characterized by a high propensity for cervical nodal metastasis, which affects the probability of regional control and survival. Until now, elective treatment of the clinically negative neck in early lesions (T(1-2)) of the oral tongue cancer remains controversial. This study attempted to identify predictive factor(s) for cervical nodal metastasis and treatment outcomes in patients with early stage SCC of the oral tongue treated primarily by surgery. Fifty patients with previously untreated Stage I/II primary tongue carcinomas with available archival specimens treated at the Royal Marsden Hospital between 1981 and 1998 were reviewed. Clinico-pathological features including age, gender, alcohol and tobacco consumption, tumour location, histological grade, tumour-stromal border, growth pattern, tumour thickness, and clinical stage were evaluated and the correlations with cervical metastases and outcome analysis were determined. The overall occult nodal metastatic rate was 40% (20/50). Tumour thickness exceeding 5 mm was statistically significantly correlated with cervical metastases (P = 0.003; relative risk = 2.429). No statistical correlation was observed between other clinico-pathological parameters and nodal metastasis. With a median follow-up of 98 months, 5-year actuarial overall, disease-specific (DSS), and relapse-free survival were 65.71, 67.77, and 68.18%, respectively. Univariate analysis for DSS showed poorer outcomes for patients with age > 60 years (P = 0.0423) and tumour thickness > 5 mm (P = 0.0067). The effect of tumour thickness was maintained (P = 0.005) on multivariate analysis. The present study indicates that the thickness of primary tumour has a strong predictive value for occult cervical metastasis and poor outcomes in patients with Stage I/II oral tongue SCC. Thus, elective neck treatment (surgery or irradiation) is indicated for tumours exceeding 5 mm thickness. Copyright 2003 Elsevier
Nodal soliton solutions for generalized quasilinear Schrödinger equations
Deng, Yinbin Peng, Shuangjie; Wang, Jixiu
2014-05-15
This paper is concerned with constructing nodal radial solutions for generalized quasilinear Schrödinger equations in R{sup N} which arise from plasma physics, fluid mechanics, as well as high-power ultashort laser in matter. For any given integer k ⩾ 0, by using a change of variables and minimization argument, we obtain a sign-changing minimizer with k nodes of a minimization problem.
Verdu, G.; Capilla, M.; Talavera, C. F.; Ginestar, D.
2012-07-01
PL equations are classical high order approximations to the transport equations which are based on the expansion of the angular dependence of the angular neutron flux and the nuclear cross sections in terms of spherical harmonics. A nodal collocation method is used to discretize the PL equations associated with a neutron source transport problem. The performance of the method is tested solving two 1D problems with analytical solution for the transport equation and a classical 2D problem. (authors)
Masè, Michela; Glass, Leon; Disertori, Marcello; Ravelli, Flavia
2012-11-15
The genesis of complex ventricular rhythms during atrial tachyarrhythmias in humans is not fully understood. To clarify the dynamics of atrioventricular (AV) conduction in response to a regular high-rate atrial activation, 29 episodes of spontaneous or pacing-induced atrial flutter (AFL), covering a wide range of atrial rates (cycle lengths from 145 to 270 ms), were analyzed in 10 patients. AV patterns were identified by applying firing sequence and surrogate data analysis to atrial and ventricular activation series, whereas modular simulation with a difference-equation AV node model was used to correlate the patterns with specific nodal properties. AV node response at high atrial rate was characterized by 1) AV patterns of decreasing conduction ratios at the shortening of atrial cycle length (from 236.3 ± 32.4 to 172.6 ± 17.8 ms) according to a Farey sequence ordering (conduction ratio from 0.34 ± 0.12 to 0.23 ± 0.06; P < 0.01); 2) the appearance of high-order alternating Wenckebach rhythms, such as 6:2, 10:2, and 12:2, associated with ventricular interval oscillations of large amplitude (407.7 ± 150.4 ms); and 3) the deterioration of pattern stability at advanced levels of block, with the percentage of stable patterns decreasing from 64.3 ± 35.2% to 28.3 ± 34.5% (P < 0.01). Simulations suggested these patterns to originate from the combined effect of nodal recovery, dual pathway physiology, and concealed conduction. These results indicate that intrinsic nodal properties may account for the wide spectrum of AV block patterns occurring during regular atrial tachyarrhythmias. The characterization of AV nodal function during different AFL forms constitutes an intermediate step toward the understanding of complex ventricular rhythms during atrial fibrillation.
Disrupted Nodal and Hub Organization Account for Brain Network Abnormalities in Parkinson’s Disease
Koshimori, Yuko; Cho, Sang-Soo; Criaud, Marion; Christopher, Leigh; Jacobs, Mark; Ghadery, Christine; Coakeley, Sarah; Harris, Madeleine; Mizrahi, Romina; Hamani, Clement; Lang, Anthony E.; Houle, Sylvain; Strafella, Antonio P.
2016-01-01
The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson’s disease (PD). This study aimed to investigate functional changes in sensorimotor and cognitive networks in Parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls (HCs) and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the HC and patient groups. We found nodal and hub changes in patients compared with HCs, including the right pre-supplementary motor area (SMA), left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex (DLPFC), and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e., right pre-SMA and right mid-insula) displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral DLPFC possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of PD. PMID:27891090
Chen, Chuanben; Zhang, Mingwei; Xu, Yuanji; Yue, Qiuyuan; Bai, Penggang; Zhou, Lin; Xiao, Youping; Zheng, Dechun; Lin, Kongqi; Qiu, Sufang; Chen, Yunbin; Pan, Jianji
2016-01-01
Abstract The aim of the study was to evaluate whether short axis and long axis on axial and coronal magnetic resonance imaging planes would reflect the tumor burden or alteration in size after induction chemotherapy in nasopharyngeal carcinoma. Patients with pathologically confirmed nasopharyngeal carcinoma (n = 37) with at least 1 positive cervical lymph node (axial short axis ≥15 mm) were consecutively enrolled in this prospective study. Lymph nodal measurements were performed along its short axis and long axis in both axial and coronal magnetic resonance imaging planes at diagnosis and after 2 cycles of induction chemotherapy. In addition, lymph nodal volumes were automatically calculated in 3D treatment-planning system, which were used as reference standard. Student's t test or nonparametric Mann–Whitney U test was used to compare the continuous quantitative variables. Meanwhile, the κ statistic and McNemar's test were used to evaluate the degree of agreement and discordance in response categorization among different measurements. Axial short axis was significantly associated with volumes at diagnosis (P < 0.001). A good agreement (κ=0.583) was found between axial short axis and volumetric criteria. However, the inconsistent lymph nodal shrinkage in 4 directions was observed. Axial short-axis shrinking was more rapid than the other 3 parameters. Interestingly, when utilizing the alternative planes for unidimensional measurements to assess tumor response, coronal short-axis showed the best concordance (κ=0.792) to the volumes. Axial short axis may effectively reflect tumor burden or change in tumor size in the assessment of target lymph nodal response after induction chemotherapy for nasopharyngeal carcinoma. However, it should be noted that axial short axis may amplify the therapeutic response. In addition, the role of coronal short axis in the assessment of tumor response needs further evaluation. PMID:26945354
Oster, Matthew E; Yang, Zhou; Stewart-Huey, Kay; Glanville, Michelle; Porter, Arlene; Campbell, Robert; Webb, Brad; Strieper, Margaret
2017-03-01
It is unclear whether cryoablation or radiofrequency ablation offers better value for treating atrioventricular nodal re-entrant tachycardia in children. We aimed to compare the value of these procedures for treating atrioventricular nodal re-entrant tachycardia in children, with value being outcomes relative to costs. We performed a retrospective cohort study of all atrioventricular nodal re-entrant tachycardia ablations for children (age⩽18 years) from July, 2009 to June, 2011 at our institution. Costs included fixed costs, miscellaneous hospital costs, and labour costs, and key outcomes were acute and long-term success (6 months) of the ablations. We conducted T-tests and regression analyses to investigate the associations between the ablation procedure type and the cost and success of the ablations. Of 96 unique cases performed by three paediatric electrophysiologists, 48 were cryoablation only, 42 radiofrequency ablation only, and six were a combination. Acute success was 100% for the cryoablation only and radiofrequency ablation only cases and 83% for the combination cases. There were no notable adverse events. The average total cost was $9636 for cryoablation cases, $9708 for radiofrequency ablation cases, and $10,967 for combination cases (p=0.51 for cryoablation only versus radiofrequency ablation only). The long-term success rate was 79.1% for cryoablation only, 92.8% for radiofrequency ablation only, and 66.7% for the combination (p=0.01 for cryoablation only versus radiofrequency ablation only), but long-term success varied notably by provider. Cryoablation and radiofrequency ablation offer similar value in the short term for the treatment of atrioventricular nodal re-entrant tachycardia in children. Differences in long-term success may vary substantially by physician, and thus may lead to differences in long-term value.
Numerical divergence effects of equivalence theory in the nodal expansion method
Zika, M.R.; Downar, T.J. )
1993-11-01
Accurate solutions of the advanced nodal equations require the use of discontinuity factors (DFs) to account for the homogenization errors that are inherent in all coarse-mesh nodal methods. During the last several years, nodal equivalence theory (NET) has successfully been implemented for the Cartesian geometry and has received widespread acceptance in the light water reactor industry. The extension of NET to other reactor types has had limited success. Recent efforts to implement NET within the framework of the nodal expansion method have successfully been applied to the fast breeder reactor. However, attempts to apply the same methods to thermal reactors such as the Modular High-Temperature Gas Reactor (MHTGR) have led to numerical divergence problems that can be attributed directly to the magnitude of the DFs. In the work performed here, it was found that the numerical problems occur in the inner and upscatter iterations of the solution algorithm. These iterations use a Gauss-Seidel iterative technique that is always convergent for problems with unity DFs. However, for an MHTGR model that requires large DFs, both the inner and upscatter iterations were divergent. Initial investigations into methods for bounding the DFs have proven unsatisfactory as a means of remedying the convergence problems. Although the DFs could be bounded to yield a convergent solution, several cases were encountered where the resulting flux solution was less accurate than the solution without DFs. For the specific case of problems without upscattering, an alternate numerical method for the inner iteration, an LU decomposition, was identified and shown to be feasible.
Gastroblastoma in a 28-year-old man with nodal metastasis: proof of the malignant potential.
Wey, Elizabeth A; Britton, Andrew J; Sferra, Joseph J; Kasunic, Tim; Pepe, Linda R; Appelman, Henry D
2012-08-01
Gastroblastoma is a newly defined neoplasm of children and young adults with only 4 reported cases to date. Morphologically, the tumor is a mixture of epithelial structures and stromal elements with minimal cytologic atypia. In these 4 reported cases, there were no metastases or postresection recurrences. We report a case of gastroblastoma in a 28-year-old man with a histologic nodal metastasis and clinical distant metastases.
[Inhibition of the sodium inactivation of the nodal membrane by anemonia sulcata toxin II].
Bergman, C; Dubois, J M; Rojas, E; Rathmayer, W
1976-05-31
A neurotoxin (ATX-II) extracted from the tentacles of Anemonia sulcata has been found to interact with the sodium channel of the nodal membrane in myelinated nerve fibres from Rana esculenta. If externally applied at low concentration (Kd = 20 muM), it reduces considerably the rate of inactivation of the sodium conductance without affecting the activation. At such concentrations, the potassium conductance is not affected. If internally applied ATX-II does not affect the membrane conductance.
Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review
Barake, Walid; Caldwell, Jane; Baranchuk, Adrian
2013-01-01
This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875
Ionic mechanisms involved in the nodal swelling of myelinated axons caused by marine toxins.
Benoit, Evelyne; Mattei, Cesar; Ouanounou, Gilles; Meunier, Frederic A; Suput, Dusan; Le Gall, Frederic; Marquais, Michel; Dechraoui, Marie Y; Molgo, Jordi
2002-01-01
This review describes the ionic mechanisms involved in the nodal swelling of frog myelinated axons caused by specific marine neurotoxins (ciguatoxins, brevetoxins, Conus consors toxin and equinatoxin-II), analysed using confocal laser scanning microscopy. We have focussed on toxins that either target neuronal voltage-dependent Na+ channels, or that form cation-selective pores and indirectly affect the functioning of the Na(+)-Ca(++)exchanger.
NASA Technical Reports Server (NTRS)
Song, Y. T.
1998-01-01
A Jacobian formulation of the pressure gradient force for use in models with topography following coordinates is proposed. It can be used in conjunction with any vertical coordinate system and is easily implemented.
NASA Technical Reports Server (NTRS)
Song, Y. T.
1998-01-01
A Jacobian formulation of the pressure gradient force for use in models with topography following coordinates is proposed. It can be used in conjunction with any vertical coordinate system and is easily implemented.
Raya, Ángel; Kawakami, Yasuhiko; Rodríguez-Esteban, Concepción; Büscher, Dirk; Koth, Christopher M.; Itoh, Tohru; Morita, Masanobu; Raya, R. Marina; Dubova, Ilir; Bessa, Joaquín Grego; de la Pompa, José Luis; Belmonte, Juan Carlos Izpisúa
2003-01-01
Left-sided expression of Nodal in the lateral plate mesoderm is a conserved feature necessary for the establishment of normal left–right asymmetry during vertebrate embryogenesis. By using gain- and loss-of-function experiments in zebrafish and mouse, we show that the activity of the Notch pathway is necessary and sufficient for Nodal expression around the node, and for proper left–right determination. We identify Notch-responsive elements in the Nodal promoter, and unveil a direct relationship between Notch activity and Nodal expression around the node. Our findings provide evidence for a mechanism involving Notch activity that translates an initial symmetry-breaking event into asymmetric gene expression. PMID:12730123
Photoinduced filling of near-nodal gap in Bi2Sr2CaCu2O8 +δ
NASA Astrophysics Data System (ADS)
Zhang, Z.; Piovera, C.; Papalazarou, E.; Marsi, M.; d'Astuto, M.; van der Beek, C. J.; Taleb-Ibrahimi, A.; Perfetti, L.
2017-08-01
We report time- and angle-resolved spectroscopic measurements in optimally doped Bi2Sr2CaCu2O8 +δ . The photoelectron intensity maps are monitored as a function of temperature, photoexcitation density, and delay time from the pump pulse. We evince that thermal fluctuations are effective only for temperatures near the critical value whereas photoinduced fluctuations scale linearly at low pumping fluence. The minimal energy to fully disrupt the superconducting gap slightly increases when moving off the nodal direction. No evidence of a pseudogap arising from other phenomena than pairing has been detected in the explored region of reciprocal space. On the other hand, a model accounting for the finite pair breaking explains the gap filling both in the near-nodal as well as in the off-nodal direction. Finally, we observed that nodal quasiparticles develop a faster dynamics when pumping the superconductor with fluence large enough to induce the total collapse of the gap.
Uehara, Masayuki; Yashiro, Kenta; Takaoka, Katsuyoshi; Yamamoto, Masamichi; Hamada, Hiroshi
2009-01-01
The abundance of retinoic acid (RA) is determined by the balance between its synthesis by retinaldehyde dehydrogenase (RALDH) and its degradation by CYP26. In particular, the dynamic expression of three CYP26 genes controls the regional level of RA within the body. Pregastrulation mouse embryos express CYP26 but not RALDH. We now show that mice lacking all three CYP26 genes manifest duplication of the body axis as a result of expansion of the Nodal expression domain throughout the epiblast. Mouse Nodal was found to contain an RA-responsive element in intron 1 that is highly conserved among mammals. In the absence of CYP26, maternally derived RA activates Nodal expression in the entire epiblast of pregastrulation embryos via this element. These observations suggest that maternal RA must be removed by embryonic CYP26 for correct Nodal expression during embryonic patterning. PMID:19605690
Nguyen, Dinh Q.; Sobczak, Henrik; Brandts, Bodo
2017-01-01
Most tachycardias in the pulmonary venous atrium are inaccessible by direct means and require either a retrograde approach or a transseptal approach for ablation. We present a case in which successful radiofrequency ablation of common atrioventricular nodal reentrant tachycardia was accomplished via a retrograde transaortic approach guided by nonfluoroscopic mapping with use of the NavX™ mapping system. The patient was a 49-year-old woman who at the age of 4 years had undergone Mustard repair for complete dextrotransposition of the great arteries. Three-dimensional reconstructions of the ascending aorta, right ventricle, systemic venous atrium, left ventricle, and superior vena cava–inferior vena cava baffle complex were created, and the left-sided His bundle was marked. After a failed attempt at ablation from the systemic venous side, we eliminated the atrioventricular nodal reentrant tachycardia by ablation from the pulmonary venous side. This case is, to our knowledge, the first report of successful radiofrequency ablation of common atrioventricular nodal reentrant tachycardia after Mustard repair for this congenital cardiac malformation in which ablation was guided by 3-dimensional nonfluoroscopic imaging. This imaging technique enabled accurate anatomic location of the ablation catheters in relation to the His bundle marked from the systemic venous side. PMID:28265215
Reticulin and NM23 staining in the interpretation of lymph nodal nevus rests.
Kanner, William A; Barry, Catherine I; Smart, Chandra N; Frishberg, David P; Binder, Scott W; Wick, Mark R
2013-06-01
Melanocytic nevus rests in lymph nodes are a known diagnostic challenge, especially in patients with a history of melanoma. Reticulin and NM23 have been studied in this context. The pattern of reticulin staining in melanomas surrounds groups/nests of melanocytes but individual cells in benign nevi. NM23, a metastasis-suppressor gene, has an association with metastatic potential in melanomas and some carcinomas. Twenty-eight cases (14 cases of metastatic melanoma to lymph nodes and 14 cases of lymph node nevus rests, all confirmed with Melan-A staining) were stained with reticulin and NM23. The pattern of reticulin staining was reported as surrounding groups if staining was noted in approximately 5-10 melanocytes in greater than 50% of the lesion but was otherwise reported as surrounding individual melanocytes. Cytoplasmic staining was considered to represent reactivity for NM23. Reticulin staining around groups of melanocytes was identified in all 14 cases of metastatic melanoma. Regarding nodal nevus rest cases, 12 of 14 cases (86%) demonstrated staining around individual melanocytes, whereas in 2 cases, reticulin surrounded melanocytic groups. NM23 staining was equivocal in all cases. Reticulin staining reliably invests groups of melanocytes in cases of metastatic melanoma, whereas in nodal nevus rests, it predominantly surrounds individual melanocytes. NM23 demonstrated no discriminatory value in this analysis. In cases in which a collection of melanocytes is present within a lymph node, reticulin deposition around individual melanocytes supports a diagnosis of lymph nodal nevus rest.
Topological protection from exceptional points in Weyl and nodal-line semimetals
NASA Astrophysics Data System (ADS)
González, J.; Molina, R. A.
2017-07-01
We investigate the topological protection of surface states in Weyl and nodal-line semimetals by characterizing them as evanescent states when the band structure is extended to complex momenta. We find in this way a sequence of exceptional points—that is, branch points with zero energy in the complex spectrum—allowing us to identify the set of surface states with complex momentum signaling the decay into the 3D semimetal. From this point of view, Weyl and nodal-line semimetals can be classified in two types depending on the way surface states decay. Type A semimetals have surface states with smaller penetration length and oscillating decay while type B semimetals have longer simple exponential decays. The difference between both types reflects in the way the branch cuts in the spectrum accommodate in the complex plane. The stability of the surface states stems in this approach from the complex structure that develops around the exceptional points, with a topological protection which is based on the fact that the branch cuts cannot be closed by small perturbations. We check this property when nodal-line semimetals are placed under circularly polarized light, where we observe that the exceptional points survive the effect of such a perturbation, though appropriate boundary conditions for zero-energy surface states cannot be satisfied in general due to the breakdown of time-reversal invariance by the radiation field.
Sesn1 is a novel gene for left-right asymmetry and mediating nodal signaling.
Peeters, Hilde; Voz, Marianne L; Verschueren, Kristin; De Cat, Bart; Pendeville, Hélène; Thienpont, Bernard; Schellens, Ann; Belmont, John W; David, Guido; Van De Ven, Wim J M; Fryns, Jean-Pierre; Gewillig, Marc; Huylebroeck, Danny; Peers, Bernard; Devriendt, Koen
2006-11-15
Remarkable progress has been made in understanding the molecular mechanisms underlying left-right asymmetry in vertebrate animal models but little is known on left-right axis formation in humans. Previously, we identified SESN1 (also known as PA26) as a candidate gene for heterotaxia by positional cloning of the breakpoint regions of a de novo translocation in a heterotaxia patient. In this study, we show by means of a zebrafish sesn1-knockdown model that Sesn1 is required for normal embryonic left-right determination. In this model, developmental defects and expression data of genes implicated in vertebrate left-right asymmetry indicate a role for Sesn1 in mediating Nodal signaling. In the lateral plate mesoderm, Nodal signaling plays a central role in left-right axis formation in vertebrates and is mediated by FoxH1 transcriptional induction. In line with this, we show that Sesn1 physically interacts with FoxH1 or a FoxH1-containing complex. Mutation analysis in a panel of 234 patients with isolated heterotaxia did not reveal mutations, indicating that these are only exceptional causes of human heterotaxia. In this study, we identify SESN1 as an indispensable gene for vertebrate left-right asymmetry and a new player in mediating Nodal signaling.
Peng, Yingying; Meng, Jianqiao; Mou, Daixiang; He, Junfeng; Zhao, Lin; Wu, Yue; Liu, Guodong; Dong, Xiaoli; He, Shaolong; Zhang, Jun; Wang, Xiaoyang; Peng, Qinjun; Wang, Zhimin; Zhang, Shenjin; Yang, Feng; Chen, Chuangtian; Xu, Zuyan; Lee, T K; Zhou, X J
2013-01-01
The parent compound of the copper-oxide high-temperature superconductors is a Mott insulator. Superconductivity is realized by doping an appropriate amount of charge carriers. How a Mott insulator transforms into a superconductor is crucial in understanding the unusual physical properties of high-temperature superconductors and the superconductivity mechanism. Here we report high-resolution angle-resolved photoemission measurement on heavily underdoped Bi₂Sr₂-xLaxCuO(₆+δ) system. The electronic structure of the lightly doped samples exhibit a number of characteristics: existence of an energy gap along the nodal direction, d-wave-like anisotropic energy gap along the underlying Fermi surface, and coexistence of a coherence peak and a broad hump in the photoemission spectra. Our results reveal a clear insulator-superconductor transition at a critical doping level of ~0.10 where the nodal energy gap approaches zero, the three-dimensional antiferromagnetic order disappears, and superconductivity starts to emerge. These observations clearly signal a close connection between the nodal gap, antiferromagnetism and superconductivity.
Anisotropic density fluctuations, plasmons, and Friedel oscillations in nodal line semimetal
NASA Astrophysics Data System (ADS)
Rhim, Jun-Won; Kim, Yong Baek
2016-04-01
Motivated by recent experimental efforts on three-dimensional semimetals, we investigate the static and dynamic density response of the nodal line semimetal by computing the polarizability for both undoped and doped cases. The nodal line semimetal in the absence of doping is characterized by a ring-shape zero energy contour in momentum space, which may be considered as a collection of Dirac points. In the doped case, the Fermi surface has a torus shape and two independent processes of the momentum transfer contribute to the singular features of the polarizability even though we only have a single Fermi surface. In the static limit, there exist two independent singularities in the second derivative of the static polarizability. This results in the highly anisotropic Friedel oscillations which show the angle-dependent algebraic power law and the beat phenomena in the oscillatory electron density near a charged impurity. Furthermore, the dynamical polarizability has two singular lines along {\\hslash }ω =γ p and {\\hslash }ω =γ p{sin}η , where η is the angle between the external momentum {p} and the plane where the nodal ring lies. From the dynamical polarizability, we obtain the plasmon modes in the doped case, which show anisotropic dispersions and angle-dependent plasma frequencies. Qualitative differences between the low and high doping regimes are discussed in light of future experiments.
Garnier, Camille; Martin-Blondel, Guillaume; Debuisson, Cécile; Dubois, Damien; Debard, Alexa; Cuzin, Lise; Massip, Patrice; Delobel, Pierre; Marchou, Bruno
2016-02-01
Cat scratch disease (CSD)'s lymphadenitis may have a protracted course with painful suppuration necessitating several needle aspirations or surgical drainage. The objective of this study was to evaluate the benefit of an intra-nodal injection of gentamicin add-on oral azithromycin treatment on the outcome of suppurated CSD's lymphadenitis. We performed a retrospective monocentric study including 51 consecutive patients diagnosed between Jan 2009 and Mar 2014 with suppurated CSD who had a positive PCR for Bartonella henselae DNA in pus collected from lymph node by needle aspiration, and who were treated with azithromycin. Among them, 26/51 patients (51%) received oral azithromycin only, of whom 8 patients (31%) were cured and 18 patients (69%) had complications, while 25/51 patients (49%) received an intra-nodal injection of gentamicin add-on oral azithromycin, of whom 16 patients (64 %) were cured and 9 patients (36%) had complications. In univariate analysis, the combined treatment was the only variable related to cure without complications (64 versus 31%, p = 0.01), but this difference did not remain statistically significant in multivariate analysis (OR = 3.84, 95% CI: 0.95-15.56, p = 0.06). Intra-nodal injection of gentamicin add-on oral azithromycin treatment might improve the outcome of patients with suppurated CSD's lymphadenitis, deserving further randomized studies.
A Computational Model of Dynein Activation Patterns that Can Explain Nodal Cilia Rotation
Chen, Duanduan; Zhong, Yi
2015-01-01
Normal left-right patterning in vertebrates depends on the rotational movement of nodal cilia. In order to produce this ciliary motion, the activity of axonemal dyneins must be tightly regulated in a temporal and spatial manner; the specific activation pattern of the dynein motors in the nodal cilia has not been reported. Contemporary imaging techniques cannot directly assess dynein activity in a living cilium. In this study, we establish a three-dimensional model to mimic the ciliary ultrastructure and assume that the activation of dynein proteins is related to the interdoublet distance. By employing finite-element analysis and grid deformation techniques, we simulate the mechanical function of dyneins by pairs of point loads, investigate the time-variant interdoublet distance, and simulate the dynein-triggered ciliary motion. The computational results indicate that, to produce the rotational movement of nodal cilia, the dynein activity is transferred clockwise (looking from the tip) between the nine doublet microtubules, and along each microtubule, the dynein activation should occur faster at the basal region and slower when it is close to the ciliary tip. Moreover, the time cost by all the dyneins along one microtubule to be activated can be used to deduce the dynein activation pattern; it implies that, as an alternative method, measuring this time can indirectly reveal the dynein activity. The proposed protein-structure model can simulate the ciliary motion triggered by various dynein activation patterns explicitly and may contribute to furthering the studies on axonemal dynein activity. PMID:26153700
Haissaguerre, M; Warin, J F; Lemetayer, P; Saoudi, N; Guillem, J P; Blanchot, P
1989-02-16
We applied a new technique of catheter ablation to treat atrioventricular nodal reentrant tachycardia and preserve anterograde conduction, performing this procedure in 21 patients with repetitive episodes of tachycardia refractory to antiarrhythmic drugs. Using atrial activation in the His-bundle lead as a reference, we selected the optimal site of ablation by positioning an electrode catheter so that atrial activation occurred simultaneously with or earlier than the reference activation during tachycardia. At this site, the His-bundle deflection was completely absent or was present only at a low amplitude (less than 0.1 mV). In the majority of patients, these criteria could be met by withdrawing the catheter 5 to 10 mm from the site of the His-bundle recording (adjacent to the reference catheter). Shocks of 160 or 240 J were delivered at this site (cumulative energy [mean +/- SD], 689 +/- 442 J). Treatment resulted in preferential abolition or impairment of retrograde nodal conduction. Anterograde conduction, although modified, was preserved in 19 patients; complete heart block persisted in 2 patients. Sixteen patients remained free of arrhythmia, without medication or implantation of a pacemaker, for a mean follow-up period of 14 +/- 8 months (range, 7 to 42). Tachycardia was not inducible in 14 patients in a follow-up electrophysiologic study performed 3.6 +/- 6 months after the procedure. We conclude that catheter ablation is an effective alternative for the treatment of atrioventricular nodal tachycardia in patients with drug-resistant tachycardia.
A coarse-mesh nodal method-diffusive-mesh finite difference method
Joo, H.; Nichols, W.R.
1994-05-01
Modern nodal methods have been successfully used for conventional light water reactor core analyses where the homogenized, node average cross sections (XSs) and the flux discontinuity factors (DFs) based on equivalence theory can reliably predict core behavior. For other types of cores and other geometries characterized by tightly-coupled, heterogeneous core configurations, the intranodal flux shapes obtained from a homogenized nodal problem may not accurately portray steep flux gradients near fuel assembly interfaces or various reactivity control elements. This may require extreme values of DFs (either very large, very small, or even negative) to achieve a desired solution accuracy. Extreme values of DFs, however, can disrupt the convergence of the iterative methods used to solve for the node average fluxes, and can lead to a difficulty in interpolating adjacent DF values. Several attempts to remedy the problem have been made, but nothing has been satisfactory. A new coarse-mesh nodal scheme called the Diffusive-Mesh Finite Difference (DMFD) technique, as contrasted with the coarse-mesh finite difference (CMFD) technique, has been developed to resolve this problem. This new technique and the development of a few-group, multidimensional kinetics computer program are described in this paper.
Measurement of the Nodal Precession of WASP-33 b via Doppler Tomography
NASA Astrophysics Data System (ADS)
Johnson, Marshall C.; Cochran, William D.; Collier Cameron, Andrew; Bayliss, Daniel
2015-09-01
We have analyzed new and archival time series spectra taken six years apart during transits of the hot Jupiter WASP-33 b, and spectroscopically resolved the line profile perturbation caused by the Rossiter-McLaughlin effect. The motion of this line profile perturbation is determined by the path of the planet across the stellar disk, which we show to have changed between the two epochs due to nodal precession of the planetary orbit. We measured rates of change of the impact parameter and the sky-projected spin-orbit misalignment of {db}/{dt}={-0.0228}-0.0018+0.0050 {{yr}}-1 and dλ /{dt}={-0\\buildrel{\\circ}\\over{.} 487}-0.076+0.089 {{yr}}-1, respectively, corresponding to a rate of nodal precession of d{{Ω }}/{dt}=0\\buildrel{\\circ}\\over{.} {373}-0.083+0.031 {{yr}}-1. This is only the second measurement of nodal precession for a confirmed exoplanet transiting a single star. Finally, we used the rate of precession to set limits on the stellar gravitational quadrupole moment of 0.0054≤slant {J}2≤slant 0.035.
NASA Astrophysics Data System (ADS)
Tsutsumi, Yasumasa; Nomoto, Takuya; Ikeda, Hiroaki; Machida, Kazushige
2016-12-01
We propose a spectroscopic method to identify the nodal gap structure in unconventional superconductors. This method is best suited for locating the horizontal line node and for pinpointing the isolated point nodes by measuring polar angle (θ ) resolved zero-energy density of states N (θ ) . This is measured by specific heat or thermal conductivity at low temperatures under a magnetic field. We examine a variety of uniaxially symmetric nodal structures, including point and/or line nodes with linear and quadratic dispersions, by solving the Eilenberger equation in vortex states. It is found that (a) the maxima of N (θ ) continuously shift from the antinodal to the nodal direction (θn) as a field increases accompanying the oscillation pattern reversal at low and high fields. Furthermore, (b) local minima emerge next to θn on both sides, except for the case of the linear point node. These features are robust and detectable experimentally. Experimental results of N (θ ) performed on several superconductors, UPd2Al3,URu2Si2,CuxBi2Se3 , and UPt3, are examined and commented on in light of the present theory.
Formin DAAM1 Organizes Actin Filaments in the Cytoplasmic Nodal Actin Network
Luo, Weiwei; Lieu, Zi Zhao; Manser, Ed; Bershadsky, Alexander D.; Sheetz, Michael P.
2016-01-01
A nodal cytoplasmic actin network underlies actin cytoplasm cohesion in the absence of stress fibers. We previously described such a network that forms upon Latrunculin A (LatA) treatment, in which formin DAAM1 was localized at these nodes. Knock down of DAAM1 reduced the mobility of actin nodes but the nodes remained. Here we have investigated DAAM1 containing nodes after LatA washout. DAAM1 was found to be distributed between the cytoplasm and the plasma membrane. The membrane binding likely occurs through an interaction with lipid rafts, but is not required for F-actin assembly. Interesting the forced interaction of DAAM1 with plasma membrane through a rapamycin-dependent linkage, enhanced F-actin assembly at the cell membrane (compared to the cytoplasm) after the LatA washout. However, immediately after addition of both rapamycin and LatA, the cytoplasmic actin nodes formed transiently, before DAAM1 moved to the membrane. This was consistent with the idea that DAAM1 was initially anchored to cytoplasmic actin nodes. Further, photoactivatable tracking of DAAM1 showed DAAM1 was immobilized at these actin nodes. Thus, we suggest that DAAM1 organizes actin filaments into a nodal complex, and such nodal complexes seed actin network recovery after actin depolymerization. PMID:27760153
Fuerschbach, Kyle; Rolland, Jannick P; Thompson, Kevin P
2012-08-27
This paper introduces the path forward for the integration of freeform optical surfaces, particularly those related to φ-polynomial surfaces, including Zernike polynomial surfaces, with nodal aberration theory. With this formalism, the performance of an optical system throughout the field of view can be anticipated analytically accounting for figure error, mount-induced errors, and misalignment. Previously, only misalignments had been described by nodal aberration theory, with the exception of one special case for figure error. As an example of these new results, three point mounting error that results in a Zernike trefoil deformation is studied for the secondary mirror of a two mirror and three mirror telescope. It is demonstrated that for the case of trefoil deformation applied to a surface not at the stop, there is the anticipated field constant contribution to elliptical coma (also called trefoil) as well as a newly identified field dependent contribution to astigmatism: field linear, field conjugate astigmatism. The magnitude of this astigmatic contribution varies linearly with the field of view; however, it has a unique variation in orientation with field that is described mathematically by a concept that is unique to nodal aberration theory known as the field conjugate vector.
Liposomal formulations for inhalation.
Cipolla, David; Gonda, Igor; Chan, Hak-Kim
2013-08-01
No marketed inhaled products currently use sustained release formulations such as liposomes to enhance drug disposition in the lung, but that may soon change. This review focuses on the interaction between liposomal formulations and the inhalation technology used to deliver them as aerosols. There have been a number of dated reviews evaluating nebulization of liposomes. While the information they shared is still accurate, this paper incorporates data from more recent publications to review the factors that affect aerosol performance. Recent reviews have comprehensively covered the development of dry powder liposomes for aerosolization and only the key aspects of those technologies will be summarized. There are now at least two inhaled liposomal products in late-stage clinical development: ARIKACE(®) (Insmed, NJ, USA), a liposomal amikacin, and Pulmaquin™ (Aradigm Corp., CA, USA), a liposomal ciprofloxacin, both of which treat a variety of patient populations with lung infections. This review also highlights the safety of inhaled liposomes and summarizes the clinical experience with liposomal formulations for pulmonary application.
Jani, S; Kishan, A; O'Connell, D; King, C; Steinberg, M; Low, D; Lamb, J
2014-06-01
Purpose: To investigate if pelvic nodal coverage for prostate patients undergoing intensity modulated radiotherapy (IMRT) can be predicted using mutual image information computed between planning and cone-beam CTs (CBCTs). Methods: Four patients with high-risk prostate adenocarcinoma were treated with IMRT on a Varian TrueBeam. Plans were designed such that 95% of the nodal planning target volume (PTV) received the prescription dose of 45 Gy (N=1) or 50.4 Gy (N=3). Weekly CBCTs (N=25) were acquired and the nodal clinical target volumes and organs at risk were contoured by a physician. The percent nodal volume receiving prescription dose was recorded as a ground truth. Using the recorded shifts performed by the radiation therapists at the time of image acquisition, CBCTs were aligned with the planning kVCT. Mutual image information (MI) was calculated between the CBCT and the aligned planning CT within the contour of the nodal PTV. Due to variable CBCT fields-of-view, CBCT images covering less than 90% of the nodal volume were excluded from the analysis, resulting in the removal of eight CBCTs. Results: A correlation coefficient of 0.40 was observed between the MI metric and the percent of the nodal target volume receiving the prescription dose. One patient's CBCTs had clear outliers from the rest of the patients. Upon further investigation, we discovered image artifacts that were present only in that patient's images. When those four images were excluded, the correlation improved to 0.81. Conclusion: This pilot study shows the potential of predicting pelvic nodal dosimetry by computing the mutual image information between planning CTs and patient setup CBCTs. Importantly, this technique does not involve manual or automatic contouring of the CBCT images. Additional patients and more robust exclusion criteria will help validate our findings.
Han, Tae Jin; Kim, Hak Jae; Wu, Hong-Gyun; Heo, Dae-Seog; Kim, Young Whan; Lee, Se-Hoon
2012-10-01
The present study was performed to assess the usefulness of involved-field irradiation and the impact of (18)F-fluorodeoxyglucose-positron emission tomography-based staging on treatment outcomes in limited-stage small cell lung cancer. Eighty patients who received definitive chemoradiotherapy for limited-stage small cell lung cancer were retrospectively analyzed. Fifty patients were treated with involved-field irradiation, which means that the radiotherapy portal includes only clinically identifiable tumors. The other 30 patients were irradiated with a comprehensive portal, including uninvolved mediastinal and/or supraclavicular lymph nodes, so-called elective nodal irradiation. No significant difference was seen in clinical factors between the two groups. At a median follow-up of 27 months (range, 5-75 months), no significant differences were observed in 3 year overall survival (44.6 vs. 54.1%, P= 0.220) and 3 year progression-free survival (24.4 vs. 42.8%, P= 0.133) between the involved-field irradiation group and the elective nodal irradiation group, respectively. For patients who did not undergo positron emission tomography scans, 3 year overall survival (29.3 vs. 56.3%, P= 0.022) and 3 year progression-free survival (11.0 vs. 50.0%, P= 0.040) were significantly longer in the elective nodal irradiation group. Crude incidences of isolated nodal failure were 6.0% in the involved-field irradiation group and 0% in the elective nodal irradiation group, respectively. All isolated nodal failures were developed in patients who had not undergone positron emission tomography scans in their initial work-ups. If patients did not undergo positron emission tomography-based staging, the omission of elective nodal irradiation resulted in impaired survival outcomes and raised the risk of isolated nodal failure. Therefore, involved-field irradiation for limited-stage small cell lung cancer might be reasonable only with positron emission tomography scan implementation.
Balasubramanian, Deepak; Ebrahimi, Ardalan; Gupta, Ruta; Gao, Kan; Elliott, Michael; Palme, Carsten E; Clark, Jonathan R
2014-12-01
To identify whether tumour thickness as a predictor of nodal metastases in oral squamous cell carcinoma differs between tongue and floor of mouth (FOM) subsites. Retrospective review of 343 patients treated between 1987 and 2012. The neck was considered positive in the presence of pathologically proven nodal metastases on neck dissection or during follow-up. There were 222 oral tongue and 121 FOM tumours. In patients with FOM tumours 2.1-4mm thick, the rate of nodal metastases was 41.7%. In contrast, for tongue cancers of a similar thickness the rate was only 11.2%. This increased to 38.5% in patients with tongue cancers that were 4.1-6mm thick. Comparing these two subsites, FOM cancers cross the critical 20% threshold of probability for nodal metastases between 1 and 2mm whereas tongue cancers cross the 20% threshold just under 4mm thickness. On logistic regression adjusting for relevant covariates, there was a significant difference in the propensity for nodal metastases based on tumour thickness according to subsite (p=0.028). Thin FOM tumours (2.1-4mm) have a high rate of nodal metastases. Elective neck dissection is appropriate in FOM tumours ⩾2mm thick and in tongue tumours ⩾4mm thick. Copyright © 2014 Elsevier Ltd. All rights reserved.
Kirton, O C; Windsor, J; Wedderburn, R; Gomez, E; Shatz, D V; Hudson-Civetta, J; Komanduri, S; Civetta, J M
1997-05-01
Paroxysmal atrioventricular nodal reentrant tachycardia is an infrequently encountered supraventricular arrhythmia that continues to present difficult management problems in the critically ill surgical patient. The purpose of this study was to evaluate the efficacy of a new treatment algorithm involving the sequential administration of different classes of antiarrhythmic agents until conversion to sinus rhythm was achieved. Nonrandomized, consecutive, protocol-driven descriptive cohort. University hospital surgical and trauma intensive care unit (ICU). During an 11-month period, we prospectively evaluated all hemodynamically stable patients who sustained new-onset atrioventricular nodal reentrant tachycardia. Vagal maneuver, followed by the rapid, sequential infusion of antiarrhythmic agents (i.e., adenosine, verapamil, and esmolol, respectively) until the arrhythmia was terminated. Twenty-seven patients (4% of all admissions) were evaluated, including 16 trauma patients (injury Severity Score of 20 +/- 8) and 11 general surgical patients (Acute Physiology and Chronic Health Evaluation II score of 17 +/- 7). Time from ICU admission to onset of atrioventricular nodal reentrant tachycardia was 4.5 +/- 5 days (median 2.5). Arrhythmia termination was achieved in all patients within minutes (mean 13 +/- 10 [SD]). Incremental sequential adenosine administration alone, however, was successful in affecting conversion to sinus rhythm in only 44% of initial episodes of atrioventricular nodal reentrant tachycardia (95% confidence interval 21% to 67%). A total of 14 (52%) patients developed 38 relapses of paroxysmal supraventricular tachycardia in the ICU after initial conversion to sinus rhythm. These relapses required additional antiarrhythmic therapy. Adenosine was only effective in 34% of the relapses (95% confidence interval 17% to 53%). Seven (50%) of these 14 patients developed multiple relapses. However, only two patients were receiving suppressive calcium-channel or
Formulations of entomopathogens as bioinsecticides
USDA-ARS?s Scientific Manuscript database
Developing a proper formulation is a necessary component for commercialization of entomopathogenic microbes as biological insecticides. The objective of this chapter is to present broad-ranging information about formulations to foster research toward developing commercial microbial-based insecticide...
Shuttle program. MCC Level C formulation requirements: Entry guidance and entry autopilot
NASA Technical Reports Server (NTRS)
Harpold, J. C.; Hill, O.
1980-01-01
A set of preliminary entry guidance and autopilot software formulations is presented for use in the Mission Control Center (MCC) entry processor. These software formulations meet all level B requirements. Revision 2 incorporates the modifications required to functionally simulate optimal TAEM targeting capability (OTT). Implementation of this logic in the MCC must be coordinated with flight software OTT implementation and MCC TAEM guidance OTT. The entry guidance logic is based on the Orbiter avionics entry guidance software. This MCC requirements document contains a definition of coordinate systems, a list of parameter definitions for the software formulations, a description of the entry guidance detailed formulation requirements, a description of the detailed autopilot formulation requirements, a description of the targeting routine, and a set of formulation flow charts.
Analytical and Characterization Studies of Organic Chemicals, Drugs, and Drug Formulation
2011-11-21
of the bulk drugs, drug products, to determine their stability under defined conditions, to prepare formulations of bulk drugs for biological...testing, and to coordinate ongoing stability studies on an artesunate dosage form with a subcontractor. 15. SUBJECT TERMS Anti-Parasitic Drugs, Chemical...Defense Agents, Chemical Analyses, Stability Studies, Formulation Development 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18
Body-oriented coordinates applied to the finite-element method
Cook, W.A.
1986-10-01
The objective of this research is to increase the accuracy of the finite-element method using coordinates intrinsic to the shape of the body being analyzed. We refer to these coordinates as body coordinates. Existing finite elements use Cartesian coordinates and are more accurate for solving rectangular-shaped problems than for solving nonrectangular-shaped problems. To check the feasibility of this research, we developed finite-element codes that used both cylindrical and Cartesian coordinates to solve problems in which the bodies were cylindrical-shaped. We obtained the most accurate solutions using the code that used cylindrical coordinates. Body coordinates become Cartesian coordinates for rectangular-shaped bodies and cylindrical coordinates for circular-shaped bodies. The body coordinate's finite-element formulation uses coordinate transformations from the body to the Cartesian coordinates. These transformations are developed using blending functions and boundary functions. Gradients of the Cartesian coordinates, with respect to body coordinates, are needed for stiffness calculations. Thus, the criterion for the blending function derivation is ''the nearest boundaries dominate,'' both for coordinate transformations and for gradient of coordinate transformations. For our studies, we developed two codes, one that uses body coordinates and one that uses Cartesian coordinates. These codes have been used to solve six example problems. 7 refs., 14 figs.
Toxicity of agrochemical formulations.
Carmichael, Neil G
2005-01-01
Most agrochemicals have physicochemical properties that make it impractical to apply them directly to crops and other targets. It is necessary to provide a concentrate of the active ingredient, to which formulation agents have been added to allow dilution with water for spraying. These ingredients perform several functions, including emulsifying, solubilizing, antifoaming, and the like. The properties of these materials are not intended to include pesticidal activity. However, some of these materials may have intrinsic toxicologic properties that should be taken into account in an overall evaluation of the safety of the product. In agriculture, exposure to these materials is sporadic and seasonal. The testing of the complete formulation is based on the evaluation of this risk, and it is concentrated on the evaluation of the short-term exposure to the concentrated product. Many of these substances are rather banal and are generally regarded as safe. Exceptions to this rule do exist, particularly concerning solvents; in such cases a fuller data package is necessary to perform risk assessment.
ERIC Educational Resources Information Center
Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.
2011-01-01
The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…
Gorman, Jamie C; Amazeen, Polemnia G; Cooke, Nancy J
2010-07-01
Team coordination consists of both the dynamics of team member interaction and the environmental dynamics to which a team is subjected. Focusing on dynamics, an approach is developed that contrasts with traditional aggregate-static concepts of team coordination as characterized by the shared mental model approach. A team coordination order parameter was developed to capture momentary fluctuations in coordination. Team coordination was observed in three-person uninhabited air vehicle teams across two experimental sessions. The dynamics of the order parameter were observed under changes of a team familiarity control parameter. Team members returned for the second session to either the same (Intact) or different (Mixed) team. 'Roadblock' perturbations, or novel changes in the task environment, were introduced in order to probe the stability of team coordination. Nonlinear dynamic methods revealed differences that a traditional approach did not: Intact and Mixed team coordination dynamics looked very different; Mixed teams were more stable than Intact teams and explored the space of solutions without the need for correction. Stability was positively correlated with the number of roadblock perturbations that were overcome successfully. The novel and non-intuitive contribution of a dynamical analysis was that Mixed teams, who did not have a long history working together, were more adaptive. Team coordination dynamics carries new implications for traditional problems such as training adaptive teams.
Transition Coordinators: Define Yourselves.
ERIC Educational Resources Information Center
Asselin, Susan B.; Todd-Allen, Mary; deFur, Sharon
1998-01-01
Describes a technique that was used successfully to identify the changing roles and responsibilities of special educators as transition coordinators. The Developing a Curriculum (DACUM) model uses people who are currently working in the occupation to define job responsibilities. The duties of a transition coordinator are identified. (CR)
ERIC Educational Resources Information Center
Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.
2011-01-01
The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…
The collective coordinates Jacobian
NASA Astrophysics Data System (ADS)
Schwartz, Moshe; Vinograd, Guy
2002-05-01
We develop an expansion for the Jacobian of the transformation from particle coordinates to collective coordinates. As a demonstration, we use the lowest order of the expansion in conjunction with a variational principle to obtain the Percus Yevick equation for a monodisperse hard sphere system and the Lebowitz equations for a polydisperse hard sphere system.
Coordinate Structures in English.
ERIC Educational Resources Information Center
Meyer, Charles F.
1996-01-01
Examines comparable speech and writing samples in the British and American components of the International Corpus of English (ICE) to study properties of coordinate structures in English. Findings indicate that "and" is a primary coordinator, that "but" and "or" are more peripheral, and that the concept of…
IVS Technology Coordinator Report
NASA Technical Reports Server (NTRS)
Whitney, Alan
2013-01-01
This report of the Technology Coordinator includes the following: 1) continued work to implement the new VLBI2010 system, 2) the 1st International VLBI Technology Workshop, 3) a VLBI Digital- Backend Intercomparison Workshop, 4) DiFX software correlator development for geodetic VLBI, 5) a review of progress towards global VLBI standards, and 6) a welcome to new IVS Technology Coordinator Bill Petrachenko.
A Finite Layer Formulation for Groundwater Flow to Horizontal Wells.
Xu, Jin; Wang, Xudong
2016-09-01
A finite layer approach for the general problem of three-dimensional (3D) flow to horizontal wells in multilayered aquifer systems is presented, in which the unconfined flow can be taken into account. The flow is approximated by an integration of the standard finite element method in vertical direction and the analytical techniques in the other spatial directions. Because only the vertical discretization is involved, the horizontal wells can be completely contained in one specific nodal plane without discretization. Moreover, due to the analytical eigenfunctions introduced in the formulation, the weighted residual equations can be decoupled, and the formulas for the global matrices and flow vector corresponding to horizontal wells can be obtained explicitly. Consequently, the bandwidth of the global matrices and computational cost rising from 3D analysis can be significantly reduced. Two comparisons to the existing solutions are made to verify the validity of the formulation, including transient flow to horizontal wells in confined and unconfined aquifers. Furthermore, an additional numerical application to horizontal wells in three-layered systems is presented to demonstrate the applicability of the present method in modeling flow in more complex aquifer systems.
Argañaraz, Martin Eduardo; Apichela, Silvana Andrea; Kenngott, Rebecca; Vermeheren, Margarethe; Rodler, Daniela; Palma, Gustavo Adolfo; Miceli, Dora Cristina; Sinowatz, Fred
2013-01-01
Members of TGF-β superfamily play a major role in the endometrial changes involved in the establishment and maintenance of pregnancy. Their deregulated expression and action could lead to absolute or partial failure of embryo implantation. Nonetheless, the precise function and mechanism of many of these cytokines remain unclear. Nodal, a transforming growth factor beta (TGF-β) superfamily member, was characterized in the human and rodent uterus and implicated in the tissue remodeling events during menstruation and embryo implantation. In order to study its possible role in the cattle reproductive process, we have analyzed Nodal expression pattern and localization in the oviduct and uterine horn during the oestrus cycle and early pregnancy (day 20). Nodal was detected both in oviduct and uterus during either the oestrus cycle or pregnancy; however, it shows a differential expression profile in the uterine horn at dioestrus and pregnancy, decreasing 1.5 and 1.4 folds in comparison with oestrus. Nodal immunostaining intensity was observed in stromal and in epithelial cells of the surface and the glandular epithelium. The staining pattern correlates with the RT-qPCR expression profile. This work is the first to evidence the presence of Nodal in the bovine reproductive tract; our data suggest that Nodal is a novel cytokine that would be involved in the remodelling occurring in the endometrium of cattle during the oestrus cycle and in the embryo implantation. The identification of new molecules that participate in endometrium cycling and/or pregnancy may be useful for predicting the ability of the uterine tissue to establish and maintain pregnancy or for detecting the infertility processes. These results highlight Nodal as a possible novel marker of the fertility process, nevertheless further studies should be done to determine its role in the reproductive system.
Ganesan, Anand N; Brooks, Anthony G; Roberts-Thomson, Kurt C; Lau, Dennis H; Kalman, Jonathan M; Sanders, Prashanthan
2012-02-21
The aim of this study was to systematically review the medical literature to evaluate the impact of AV nodal ablation in patients with heart failure and coexistent atrial fibrillation (AF) receiving cardiac resynchronization therapy (CRT). CRT has a substantial evidence base in patients in sinus rhythm with significant systolic dysfunction, symptomatic heart failure, and prolonged QRS duration. The role of CRT is less well established in AF patients with coexistent heart failure. AV nodal ablation has recently been suggested to improve outcomes in this group. Electronic databases and reference lists through September 15, 2010, were searched. Two reviewers independently evaluated citation titles, abstracts, and articles. Studies reporting the outcomes after AV nodal ablation in patients with AF undergoing CRT for symptomatic heart failure and left ventricular dyssynchrony were selected. Data were extracted from 6 studies, including 768 CRT-AF patients, composed of 339 patients who underwent AV nodal ablation and 429 treated with medical therapy aimed at rate control alone. AV nodal ablation in CRT-AF patients was associated with significant reductions in all-cause mortality (risk ratio: 0.42 [95% confidence interval: 0.26 to 0.68]), cardiovascular mortality (risk ratio: 0.44 [95% confidence interval: 0.24 to 0.81]), and improvement in mean New York Heart Association functional class (risk ratio: -0.52 [95% confidence interval: -0.87 to -0.17]). AV nodal ablation was associated with a substantial reduction in all-cause mortality and cardiovascular mortality and with improvements in New York Heart Association functional class compared with medical therapy in CRT-AF patients. Randomized controlled trials are warranted to confirm the efficacy and safety of AV nodal ablation in this patient population. © 2012 American College of Cardiology Foundation.
A Superspace Description of Chern-Simons Theory in Batalin-Vilkovisky Formulation
NASA Astrophysics Data System (ADS)
Upadhyay, Sudhaker; Dwivedi, Manoj Kumar; Mandal, Bhabani Prasad
2015-06-01
We discuss the extended BRST and anti-BRST symmetry (including shift symmetry) in the Batalin-Vilkovisky (BV) formulation for the Chern-Simons (CS) theories in (2 + 1) spacetime dimensions. Further we develop the superspace description of BV formulation for such theories. Interestingly, the extended BRST invariant CS theories can be described in superspace in covariant manner with the help of one more (Grassmann) coordinate. However, a superspace with two Grassmann coordinates are required for a manifestly covariant formulation of the extended BRST and extended anti-BRST invariant actions for these theories.
Delineation of Internal Mammary Nodal Target Volumes in Breast Cancer Radiation Therapy.
Jethwa, Krishan R; Kahila, Mohamed M; Hunt, Katie N; Brown, Lindsay C; Corbin, Kimberly S; Park, Sean S; Yan, Elizabeth S; Boughey, Judy C; Mutter, Robert W
2017-03-15
The optimal clinical target volume for internal mammary (IM) node irradiation is uncertain in an era of increasingly conformal volume-based treatment planning for breast cancer. We mapped the location of gross internal mammary lymph node (IMN) metastases to identify areas at highest risk of harboring occult disease. Patients with axial imaging of IMN disease were identified from a breast cancer registry. The IMN location was transferred onto the corresponding anatomic position on representative axial computed tomography images of a patient in the treatment position and compared with consensus group guidelines of IMN target delineation. The IMN location in 67 patients with 130 IMN metastases was mapped. The location was in the first 3 intercostal spaces in 102 of 130 nodal metastases (78%), whereas 18 of 130 IMNs (14%) were located caudal to the third intercostal space and 10 of 130 IMNs (8%) were located cranial to the first intercostal space. Of the 102 nodal metastases within the first 3 intercostal spaces, 54 (53%) were located within the Radiation Therapy Oncology Group consensus volume. Relative to the IM vessels, 19 nodal metastases (19%) were located medially with a mean distance of 2.2 mm (SD, 2.9 mm) whereas 29 (28%) were located laterally with a mean distance of 3.6 mm (SD, 2.5 mm). Ninety percent of lymph nodes within the first 3 intercostal spaces would have been encompassed within a 4-mm medial and lateral expansion on the IM vessels. In women with indications for elective IMN irradiation, a 4-mm medial and lateral expansion on the IM vessels may be appropriate. In women with known IMN involvement, cranial extension to the confluence of the IM vein with the brachiocephalic vein with or without caudal extension to the fourth or fifth interspace may be considered provided that normal tissue constraints are met. Copyright © 2016 Elsevier Inc. All rights reserved.
Rieken, Malte; Kluth, Luis A; Seitz, Christian; Abufaraj, Mohammad; Foerster, Beat; Mathieu, Romain; Karakiewicz, Pierre I; Bachmann, Alexander; Briganti, Alberto; Rouprê, Morgan; Gönen, Mithat; Shariat, Shahrokh F; Seebacher, Veronika
2017-08-24
We sought to externally validate our pathologic nodal staging score (pNSS) model, which allows for quantification of the likelihood that a pathologically node-negative patient will not have lymph node (LN) metastasis after radical prostatectomy for prostate cancer (PCa) in a population-based cohort. We analyzed data from 50,598 patients treated with radical prostatectomy and pelvic LN dissection using the Surveillance, Epidemiology, and End Results database. We estimated the sensitivity of pathologic nodal staging using a β-binomial model and developed a novel pNSS model, which represents the probability that a patient's PCa has been correctly staged as node negative as a function of the number of examined LNs. These findings were compared against those from the original cohort of 7135 patients. The mean and median number of LNs removed was 6.5 and 5, respectively (range, 1-89; interquartile range, 2-8), and 96.9% of the patients (n = 49,020) had stage pN0. Similar to the original cohort, the probability of missing a positive LN decreased with the increasing number of LNs examined. In both the validation and the original cohort, the number of LNs needed to correctly stage a patient's disease as node negative increased with more advanced tumor stage, higher Gleason sum, positive surgical margins, and higher preoperative prostate-specific antigen levels. We have confirmed that the number of examined LNs needed for adequate nodal staging in PCa depends on the pathologic tumor stage, Gleason sum, surgical margins status, and preoperative prostate-specific antigen. We externally validated our pNSS in a population-based cohort, which could help to refine decision-making regarding the administration of adjuvant therapy. Copyright © 2017 Elsevier Inc. All rights reserved.
Plant regeneration from single-nodal-stem explants of legume tree Prosopis alba Griseb.
Castillo de Meier, G; Bovo, O A
2000-08-01
Seeds of Prosopis alba were scarified with abrasive paper and placed to germinate on MS (Murashige and Skoog 1962) nutrient medium. After 7 days of culture, the basal part of cotyledons was removed and pieces of 4 mm" from distal parts were cultured on Murashige and Skoog (1962) mineral salts and vitamins (MS) (3% sucrose) supplemented with growth regulators. Callus proliferation took place in the majority of the media tested. A low percentage of calluses with green buds that developed on MS basal medium containing 0.1 mg.L-1 2,4-D alone or supplemented with BAP at 0.1 mg.L-1 was observed. Neither cotyledonary segments in any medium assayed regenerated the whole plants. Bud elongation (near 70%) was achieved when single-nodal-stem segments cut from 20 days old seedlings were cultured on MS salts supplemented with 3 mg.L-1 NAA or 3 mg.L-1 IBA combined with 0.05 mg.L-1 KIN after 60 days in culture. Multiple shoots per bud were also observed. Single-nodal-stem segments from five-year-old plants were also cultured on the same media used for seedling explants. Maximal frequency of explants with bud elongation (near 70%) was found on MS with 0.1 mg.L-1 NAA plus 1 mg.L-1 BAP after 60 days of culture. Single-nodal-stem explants cut from adult trees (more than 20 years) were also employed, but the number of bud elongation was lesser. For rooting, the elongated shoots were transferred to a semisolid or liquid MS culture medium employing a paper bridge, supplemented with 0.5 mg.L-1 IBA or 0.1 mg.L-1 NAA.
Integrated rate-dependent and dual pathway AV nodal functions: principles and assessment framework.
Billette, Jacques; Tadros, Rafik
2014-01-15
The atrioventricular (AV) node conducts slowly and has a long refractory period. These features sustain the filtering of atrial impulses and hence are often modulated to optimize ventricular rate during supraventricular tachyarrhythmias. The AV node is also the site of a clinically common reentrant arrhythmia. Its function is assessed for a variety of purposes from its responses to a premature protocol (S1S2, test beats introduced at different cycle lengths) repeatedly performed at different basic rates and/or to an incremental pacing protocol (increasingly faster rates). Puzzlingly, resulting data and interpretation differ with protocols as well as with chosen recovery and refractory indexes, and are further complicated by the presence of built-in fast and slow pathways. This problem applies to endocavitary investigations of arrhythmias as well as to many experimental functional studies. This review supports an integrated framework of rate-dependent and dual pathway AV nodal function that can account for these puzzling characteristics. The framework was established from AV nodal responses to S1S2S3 protocols that, compared with standard S1S2 protocols, allow for an orderly quantitative dissociation of the different factors involved in changes in AV nodal conduction and refractory indexes under rate-dependent and dual pathway function. Although largely based on data from experimental studies, the proposed framework may well apply to the human AV node. In conclusion, the rate-dependent and dual pathway properties of the AV node can be integrated within a common functional framework the contribution of which to individual responses can be quantitatively determined with properly designed protocols and analytic tools.
Shariat, Shahrokh F; Rink, Michael; Ehdaie, Behfar; Xylinas, Evanguelos; Babjuk, Marek; Merseburger, Axel S; Svatek, Robert S; Cha, Eugene K; Tagawa, Scott T; Fajkovic, Harun; Novara, Giacomo; Karakiewicz, Pierre I; Trinh, Quoc-Dien; Daneshmand, Siamak; Lotan, Yair; Kassouf, Wassim; Fritsche, Hans-Martin; Chun, Felix K; Sonpavde, Guru; Joual, Abdennabi; Scherr, Douglas S; Gonen, Mithat
2013-02-01
Radical cystectomy (RC) with pelvic lymph node dissection (PLND) is the standard of care for high-risk non-muscle-invasive and muscle-invasive bladder cancer (BCa). To develop a model that allows quantification of the likelihood that a pathologically node-negative patient has, indeed, no positive nodes. We analyzed data from 4335 patients treated with RC and PLND without neoadjuvant chemotherapy at 12 international academic centers. Patients underwent RC and PLND. We estimated the sensitivity of pathologic nodal staging using a beta-binomial model and developed a pathologic (postoperative) nodal staging score (pNSS) that represents the probability that a patient is correctly staged as node negative as a function of the number of examined nodes. Overall, the probability of missing a positive node decreases with the increasing number of nodes examined (52% if 3 nodes are examined, 40% if 5 are examined, and 26% if 10 are examined). The proportion of having a positive node increased proportionally with advancing pathologic T stage and lymphovascular invasion (LVI). Patients with LVI who had 25 examined nodes would have a pNSS of 80% (pT1), 88% (pT2), and 66% (pT3-T4), whereas 10 examined nodes were sufficient for pNSS exceeding 90% in patients without LVI and pT0-T2 tumors. This study is limited because of its retrospective design and multicenter nature. We developed a tool that estimates the likelihood of lymph node (LN) metastasis in BCa patients treated with RC by evaluating the number of examined nodes, the pathologic T stage, and LVI. The pNSS indicates the adequacy of nodal staging in LN-negative patients. This tool could help to refine clinical decision making regarding adjuvant chemotherapy, follow-up scheduling, and inclusion in clinical trials. Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Scaling of Harmonic Oscillator Eigenfunctions and Their Nodal Sets Around the Caustic
NASA Astrophysics Data System (ADS)
Hanin, Boris; Zelditch, Steve; Zhou, Peng
2017-03-01
We study the scaling asymptotics of the eigenspace projection kernels Π_{hbar, E}(x,y) of the isotropic Harmonic Oscillator {hat{H}_{hbar} = - hbar^2 Δ +|x|^2} of eigenvalue {E = hbar(N + d/2)} in the semi-classical limit {hbar to 0} . The principal result is an explicit formula for the scaling asymptotics of Π_{hbar, E}(x,y) for x, y in a {hbar^{2/3}} neighborhood of the caustic C_E as {hbar → 0.} The scaling asymptotics are applied to the distribution of nodal sets of Gaussian random eigenfunctions around the caustic as {hbar to 0} . In previous work we proved that the density of zeros of Gaussian random eigenfunctions of {hat{H}_{hbar}} have different orders in the Planck constant {hbar} in the allowed and forbidden regions: In the allowed region the density is of order {hbar^{-1}} while it is {hbar^{-1/2}} in the forbidden region. Our main result on nodal sets is that the density of zeros is of order {hbar^{-2/3}} in an {hbar^{2/3}} -tube around the caustic. This tube radius is the `critical radius'. For annuli of larger inner and outer radii {hbar^{α}} with {0 < α < 2/3} we obtain density results that interpolate between this critical radius result and our prior ones in the allowed and forbidden region. We also show that the Hausdorff ( d-2)-dimensional measure of the intersection of the nodal set with the caustic is of order {hbar^{- 2/3}}.
Papagiannis, John; Beissel, Daniel Joseph; Krause, Ulrich; Cabrera, Michel; Telishevska, Marta; Seslar, Stephen; Johnsrude, Christopher; Anderson, Charles; Tisma-Dupanovic, Svjetlana; Connelly, Diana; Avramidis, Dimosthenis; Carter, Christopher; Kornyei, Laszlo; Law, Ian; Von Bergen, Nicholas; Janusek, Jan; Silva, Jennifer; Rosenthal, Eric; Willcox, Mark; Kubus, Peter; Hessling, Gabriele; Paul, Thomas
2017-07-01
The relationship of atrioventricular nodal reentrant tachycardia to congenital heart disease (CHD) and the outcome of catheter ablation in this population have not been studied adequately. A multicenter retrospective study was performed on patients with CHD who had atrioventricular nodal reentrant tachycardia and were treated with catheter ablation. There were 109 patients (61 women), aged 22.1±13.4 years. The majority, 86 of 109 (79%), had CHD resulting in right heart pressure or volume overload. Patients were divided into 2 groups: group A (n=51) with complex CHD and group B (n=58) with simple CHD. There were no significant differences between groups in patients' growth parameters, use of 3-dimensional imaging, and type of ablation (radiofrequency versus cryoablation). Procedure times (251±117 versus 174±94 minutes; P=0.0006) and fluoroscopy times (median 20.8 versus 16.6 minutes; P=0.037) were longer in group A versus group B. There were significant differences between groups in the acute success of ablation (82% versus 97%; P=0.04), risk of atrioventricular block (14 versus 0%; P=0.004), and need for chronic pacing (10% versus 0%; P=0.008). There was no permanent atrioventricular block in patients who underwent cryoablation. After 3.2±2.7 years of follow-up, long-term success was 86% in group A and 100% in group B (P=0.004). Atrioventricular nodal reentrant tachycardia can complicate the course of patients with CHD. This study demonstrates that the outcome of catheter ablation is favorable in patients with simple CHD. Patients with complex CHD have increased risk of procedural failure and atrioventricular block. © 2017 American Heart Association, Inc.
Mirk, Paoletta; Treglia, Giorgio; Salsano, Marco; Basile, Pietro; Giordano, Alessandro; Bonomo, Lorenzo
2011-01-01
Aim. to compare 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) to sentinel lymph node biopsy (SLNB) for regional lymph nodal staging in patients with melanoma. Methods. We performed a literature review discussing original articles which compared FDG-PET to SLNB for regional lymph nodal staging in patients with melanoma. Results and Conclusions. There is consensus in the literature that FDG-PET cannot replace SLNB for regional lymph nodal staging in patients with melanoma. PMID:22242204
Rosai-Dorfman Disease with nodal and extranodal involvements: A case report
Najafi-Sani, Mehri; Saneian, Hossein; Mahjoub, Fatemeh
2011-01-01
Rosai-Dorfman disease (RDD) is a rare lymphoproliferative disorder with nodal and extranodal involvements. Here we report a case of RDD in a 15-year-old female who presented with epigastric pain, fatigue, Raynaud phenomenon in fingers, submandibular lymphadenopathy, proptosis, hepatosplenomegaly, and round shape painless patches on the extensor surfaces. Histological examination of the submandibular lymph nodes and skin biopsy demonstrated evidences of RDD. Patient was treated with prednisone and thereafter, with azathioprine. After one year, prednisone was discontinued and all of the symptoms and signs, except proptosis, were resolved. This report highlights the extranodal manifestations of RDD. The presentation, differential diagnosis, and treatment are discussed. PMID:22973396
NASA Technical Reports Server (NTRS)
Van Patten, R. A.; Everitt, C. W. F.
1975-01-01
In 1918, J. Lense and H. Thirring calculated that a moon in orbit around a massive rotating planet would experience a nodal dragging effect due to general relativity. We describe an experiment to measure this effect with two counter-orbiting drag-free satellites in polar earth orbit. For a 2 1/2 year experiment, the measurement accuracy should approach 1%. In addition to precision tracking data from existing ground stations, satellite-to-satellite Doppler ranging data are taken at points of passing near the poles. New geophysical information on both earth harmonics and tidal effects is inherent in the polar ranging data.
PoroTomo Subtask 6.3 Nodal Seismometer Earthquake Data
Kurt Feigl
2016-03-21
90-second records of data from 238 three-component nodal seismometer deployed at Bradys geothermal field. The time window catches an earthquake arrival. Earthquake data from USGS online catalog: Magnitude: 4.3 ml Â± 0.4 Location: 38.479Â°N 118.366Â°W Â± 0.7 km Depth: 9.9 km Â± 0.7 Date and Time: 2016-03-21 07:37:10.535 UTC http://earthquake.usgs.gov/earthquakes/eventpage/nn00536374#executive
NASA Technical Reports Server (NTRS)
Wilson, Deborah A.; Weigel, Russell, C.; Wheeler, Raymond M.; Sager, John C.
1993-01-01
The effects of light spectral quality on the growth of in vitro nodal cutting of potato (Solanum tuberosum) cultivars Norland, Superior, Kennebec, and Denali were examined. The different light spectra were provided by Vita-Lite fluorescent (VF) (a white light control), blue fluorescent (BF), red fluorescent (RF), low-pressure sodium (LPS), and a combination of low-pressure sodium plus cool-white fluorescent lamp (LPS/CWF). Results suggested that shoot morphologic development of in vitro grown potato plants can be controlled by controlling irradiant spectral quality.
Statistics of nodal points of in-plane random waves in elastic media.
Maksimov, Dmitrii N; Sadreev, Almas F
2008-05-01
We consider the nodal points (NPs) u=0 and v=0 of the in-plane vectorial displacements u=(u,v) which obey the Navier-Cauchy equation. Similar to the Berry conjecture of quantum chaos, we present the in-plane eigenstates of chaotic billiards as the real part of the superposition of longitudinal and transverse plane waves with random phases. By an average over random phases we derive the mean density and correlation function of NPs. Consequently we consider the distribution of the nearest distances between NPs.
Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code
Sullivan, T.J.
1986-05-01
In support of the US Department of Energy's Stirling Engine Highway Vehicle Systems program, the NASA Lewis Research Center investigated whether bypassing the P-40 Stirling engine heater during regenerative cooling would improve the engine thermal efficiency. The investigation was accomplished by using the Lewis nodal-analysis Stirling engine computer model. Bypassing the P-40 Stirling engine heater at full power resulted in a rise in the indicated thermal efficiency from 40.6 to 41.0 percent. For the idealized (some losses not included) heater bypass that was analyzed, this benefit is not considered significant.
Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code
NASA Technical Reports Server (NTRS)
Sullivan, T. J.
1986-01-01
In support of the U.S. Department of Energy's Stirling Engine Highway Vehicle Systems program, the NASA Lewis Research Center investigated whether bypassing the P-40 Stirling engine heater during regenerative cooling would improve engine performance. The Lewis nodal-analysis Stirling engine computer simulation was used for this investigation. Results for the heater-bypass concept showed no significant improvement in the indicated thermal efficiency for the P-40 Stirling engine operating at full-power and part-power conditions. Optimizing the heater tube length produced a small increase in the indicated thermal efficiency with the heater-bypass concept.
A nodal expansion method for the neutron diffusion equation in cylindrical geometry
Komlev, O.G.; Suslov, I.R.
1995-12-31
A polynomial nodal expansion method (NEM) is applied to solve multigroup diffusion equations in cylindrical R-Z geometry, Fourth-order polynomials are used to approximate one dimensional (1D) transverse integrated fluxes. The special set of the basis functions is used in R-direction. The transverse integrated leakages are approximated by both constant and quadratic polynomials. Preliminary efficiency evaluation of the NEM is carried out for a fast breeder reactor (FBR) model problem. Results indicate computational efficiency of NEM in comparison with finite-difference method (FDM).
Gnanaraj, Wesely Edward; Antonisamy, Johnson Marimuthu; R B, Mohanamathi; Subramanian, Kavitha Marappampalyam
2012-01-01
To develop the reproducible in vitro propagation protocols for the medicinally important plants viz., Achyranthes aspera (A. aspera) L. and Achyranthes bidentata (A. bidentata) Blume using nodal segments as explants. Young shoots of A. aspera and A. bidentata were harvested and washed with running tap water and treated with 0.1% bavistin and rinsed twice with distilled water. Then the explants were surface sterilized with 0.1% (w/v) HgCl2 solutions for 1 min. After rinsing with sterile distilled water for 3-4 times, nodal segments were cut into smaller segments (1 cm) and used as the explants. The explants were placed horizontally as well as vertically on solid basal Murashige and Skoog (MS) medium supplemented with 3% sucrose, 0.6% (w/v) agar (Hi-Media, Mumbai) and different concentration and combination of 6-benzyl amino purine (BAP), kinetin (Kin), naphthalene acetic acid (NAA) and indole acetic acid (IAA) for direct regeneration. Adventitious proliferation was obtained from A. aspera and A. bidentata nodal segments inoculated on MS basal medium with 3% sucrose and augmented with BAP and Kin with varied frequency. MS medium augmented with 3.0 mg/L of BAP showed the highest percentage (93.60±0.71) of shootlets formation for A. aspera and (94.70±0.53) percentages for A. bidentata. Maximum number of shoots/explants (10.60±0.36) for A. aspera and (9.50±0.56) for A. bidentata was observed in MS medium fortified with 5.0 mg/L of BAP. For A. aspera, maximum mean length (5.50±0.34) of shootlets was obtained in MS medium augmented with 3.0 mg/L of Kin and for A. bidentata (5.40±0.61) was observed in the very same concentration. The highest percentage, maximum number of rootlets/shootlet and mean length of rootlets were observed in 1/2 MS medium supplemented with 1.0 mg/L of IBA. Seventy percentages of plants were successfully established in polycups. Sixty eight percentages of plants were well established in the green house condition. Sixty five percentages of
NASA Technical Reports Server (NTRS)
Wilson, Deborah A.; Weigel, Russell, C.; Wheeler, Raymond M.; Sager, John C.
1993-01-01
The effects of light spectral quality on the growth of in vitro nodal cutting of potato (Solanum tuberosum) cultivars Norland, Superior, Kennebec, and Denali were examined. The different light spectra were provided by Vita-Lite fluorescent (VF) (a white light control), blue fluorescent (BF), red fluorescent (RF), low-pressure sodium (LPS), and a combination of low-pressure sodium plus cool-white fluorescent lamp (LPS/CWF). Results suggested that shoot morphologic development of in vitro grown potato plants can be controlled by controlling irradiant spectral quality.
Nodal quasiparticles and the onset of spin-density-wave order in cuprate superconductors.
Pelissetto, Andrea; Sachdev, Subir; Vicari, Ettore
2008-07-11
We present a theory for the onset of spin-density-wave order in the superconducting ground state of the cuprates. We compute the scaling dimensions of allowed perturbations of a "relativistic" fixed point with O4 x O(3) symmetry, including those associated with the fermionic nodal Bogoliubov quasiparticles. Analyses of up to six loops show that all perturbations with square lattice symmetry are likely irrelevant. We demonstrate that the fermion spectral functions are primarily damped by the coupling to fluctuations of a composite field with Ising nematic order. A number of other experimental implications are also discussed.
A p-adaptive LCP formulation for the compressible Navier-Stokes equations
NASA Astrophysics Data System (ADS)
Cagnone, J. S.; Vermeire, B. C.; Nadarajah, S.
2013-01-01
This paper presents a polynomial-adaptive lifting collocation penalty (LCP) formulation for the compressible Navier-Stokes equations. The LCP formulation is a high-order nodal scheme in differential form. This format, although computationally efficient, complicates the treatment of non-uniform polynomial approximations. In Cagnone and Nadarajah (2012) [9], we proposed to circumvent this difficulty by employing specially designed elements inserted at the interface where the interpolation degree varies. In the present study we examine the applicability of this approach to the discretization of the Navier-Stokes equations, with focus put on the treatment of the viscous fluxes. The stability of the scheme is analyzed with the scalar diffusion equation and the merits of the approach are demonstrated with various p-adaptive simulations.
Gong, Yuehua; Guo, Ying; Hai, Yanan; Yang, Hao; Liu, Yang; Yang, Shi; Zhang, Zhenzhen; Ma, Meng; Liu, Linhong; Li, Zheng; He, Zuping
2014-01-01
Colorectal cancer is one of the most common and fatal tumors. However, molecular mechanisms underlying carcinogenesis of colorectal cancer remain largely undefined. Here, we explored the expression and function of Nodal in colon cancer stem cells (CCSCs). Nodal and its receptors were present in numerous human colorectal cancer cell lines. NODAL and ALK-4 were coexpressed in human colon cancerous tissues, and NODAL, CD24, and CD44, markers for CCSCs, were expressed at higher levels in human colon cancerous tissues than adjacent noncancerous colon tissues. Human CCSCs were isolated by magnetic activated cell sorting using anti-CD24 and anti-CD44. Nodal transcript and protein were hardly detectable in CD44- or CD24-negative human colorectal cancer cell lines, whereas Nodal and its receptors were present in CCSCs. Notably, Nodal facilitated spheroid formation of human CCSCs, and phosphorylation of Smad2 and Smad3 was activated by Nodal in cells of spheres derived from human CCSCs. Collectively, these results suggest that Nodal promotes the self-renewal of human CCSCs and mediate carcinogenesis of human colorectal cancer via an autocrine manner through Smad2/3 pathway. This study provides a novel insight into molecular mechanisms controlling fate of human CCSCs and offers new targets for gene therapy of human colorectal cancer.
Brown, Stephanie; Teo, Adrian; Pauklin, Siim; Hannan, Nicholas; Cho, Candy H-H; Lim, Bing; Vardy, Leah; Dunn, N Ray; Trotter, Matthew; Pedersen, Roger; Vallier, Ludovic
2011-08-01
Activin/Nodal signaling is necessary to maintain pluripotency of human embryonic stem cells (hESCs) and to induce their differentiation toward endoderm. However, the mechanisms by which Activin/Nodal signaling achieves these opposite functions remain unclear. To unravel these mechanisms, we examined the transcriptional network controlled in hESCs by Smad2 and Smad3, which represent the direct effectors of Activin/Nodal signaling. These analyses reveal that Smad2/3 participate in the control of the core transcriptional network characterizing pluripotency, which includes Oct-4, Nanog, FoxD3, Dppa4, Tert, Myc, and UTF1. In addition, similar experiments performed on endoderm cells confirm that a broad part of the transcriptional network directing differentiation is downstream of Smad2/3. Therefore, Activin/Nodal signaling appears to control divergent transcriptional networks in hESCs and in endoderm. Importantly, we observed an overlap between the transcriptional network downstream of Nanog and Smad2/3 in hESCs; whereas, functional studies showed that both factors cooperate to control the expression of pluripotency genes. Therefore, the effect of Activin/Nodal signaling on pluripotency and differentiation could be dictated by tissue specific Smad2/3 partners such as Nanog, explaining the mechanisms by which signaling pathways can orchestrate divergent cell fate decisions. Copyright © 2011 AlphaMed Press.
Evidence of Topological Nodal-Line Fermions in ZrSiSe and ZrSiTe
NASA Astrophysics Data System (ADS)
Hu, Jin; Tang, Zhijie; Liu, Jinyu; Liu, Xue; Zhu, Yanglin; Graf, David; Myhro, Kevin; Tran, Son; Lau, Chun Ning; Wei, Jiang; Mao, Zhiqiang
2016-07-01
A Dirac nodal-line semimetal phase, which represents a new quantum state of topological materials, has been experimentally realized only in a few systems, including PbTaSe2 , PtSn4 , and ZrSiS. In this Letter, we report evidence of nodal-line fermions in ZrSiSe and ZrSiTe probed in de Haas-van Alphen quantum oscillations. Although ZrSiSe and ZrSiTe share a similar layered structure with ZrSiS, our studies show the Fermi surface (FS) enclosing a Dirac nodal line has a 2D character in ZrSiTe, in contrast with 3D-like FS in ZrSiSe and ZrSiS. Another important property revealed in our experiment is that the nodal-line fermion density in this family of materials (˜1020 cm-3 ) is much higher than the Dirac fermion density of other topological materials with discrete nodes. In addition, we have demonstrated ZrSiSe and ZrSiTe single crystals can be thinned down to 2D atomic thin layers through microexfoliation, which offers the first platform to explore exotic properties of topological nodal-line fermions in low dimensions.
Evidence of Topological Nodal-Line Fermions in ZrSiSe and ZrSiTe.
Hu, Jin; Tang, Zhijie; Liu, Jinyu; Liu, Xue; Zhu, Yanglin; Graf, David; Myhro, Kevin; Tran, Son; Lau, Chun Ning; Wei, Jiang; Mao, Zhiqiang
2016-07-01
A Dirac nodal-line semimetal phase, which represents a new quantum state of topological materials, has been experimentally realized only in a few systems, including PbTaSe_{2}, PtSn_{4}, and ZrSiS. In this Letter, we report evidence of nodal-line fermions in ZrSiSe and ZrSiTe probed in de Haas-van Alphen quantum oscillations. Although ZrSiSe and ZrSiTe share a similar layered structure with ZrSiS, our studies show the Fermi surface (FS) enclosing a Dirac nodal line has a 2D character in ZrSiTe, in contrast with 3D-like FS in ZrSiSe and ZrSiS. Another important property revealed in our experiment is that the nodal-line fermion density in this family of materials (∼10^{20} cm^{-3}) is much higher than the Dirac fermion density of other topological materials with discrete nodes. In addition, we have demonstrated ZrSiSe and ZrSiTe single crystals can be thinned down to 2D atomic thin layers through microexfoliation, which offers the first platform to explore exotic properties of topological nodal-line fermions in low dimensions.
Lim, R S; Evans, L; George, A P; de Alwis, N; Stimpson, P; Merriel, S; Giddings, C E B; Billah, B; Smith, J A; Safdar, A; Sigston, E
2017-01-01
Nodal metastasis is an important prognostic factor in head and neck squamous cell carcinoma. This study aimed to determine the average nodal basin yield per level of neck dissection, and to investigate if age, gender, body mass index, tumour size, depth of tumour invasion and p16 status influence nodal yield. A retrospective review of 185 patients with head and neck squamous cell carcinoma generated 240 neck dissection specimens. The respective mean nodal yields for levels I, II, III, IV and V were 5.27, 9.43, 8.49, 7.43 and 9.02 in non-cutaneous squamous cell carcinoma patients, and 4.2, 7.57, 9.65, 4.33 and 12.29 in cutaneous squamous cell carcinoma patients. Multiple regression analysis revealed that p16-positive patients with mucosal squamous cell carcinoma yielded, on average, 2.4 more nodes than their p16-negative peers (p = 0.04, 95 per cent confidence interval = 0.116 to 4.693). This figure was 3.84 (p = 0.008, 95 per cent confidence interval = 1.070 to 6.605) for p16-positive patients with oral cavity squamous cell carcinoma. In mucosal squamous cell carcinoma, p16-positive status significantly influenced nodal yield, with the impact being more pronounced in oral cavity squamous cell carcinoma patients.
Castellanos, A; Agha, A S; Mendoza, I J; Sung, R J
1977-01-01
Invasive electrophysiological studies were performed in 2 symptomatic patients with recurrent arrhythmias in which impulse formation presumably occured within atrioventricular nodal bypass tracts. Case 1 had ectopic beats arising within, or close to, the upper end of a left-sided atrioventricular nodal bypass tract of the type described by Brechenmacher. In addition, this conduction was 'concealed' during sinus rhythm and right atrial pacing because the relatively prolonged right-to-left atrial conduction time allowed right atrial impulses to reach the His bundle via the atrioventricular node before they could do so through the atrioventricular nodal bypass tract. Case 2 had ectopic beats arising in a right-sided atrioventricular nodal bypass tract which did not conduct in either forward or retrograde directions, its presence being detected only when initiating impulses. However, it could not be determined whether this tract was an 'abnormal' atrio-His connection or a 'normal' transitional (atrio-atrioventricular nodal) tract. Though intracardiac studies complement body surface recordings, they should be interpreted with knowledge of their inherent limitations. PMID:884022
General curvilinear coordinate systems
NASA Technical Reports Server (NTRS)
Thompson, J. P.
1982-01-01
The basic ideas of the construction and use of numerically-generated boundary-fitted coordinate systems for the numerical solution of partial differential equations are discussed. With such coordinate systems, all computation can be done on a fixed square grid in the rectangular transformed region regardless of the shape or movement of the physical boundaries. A number of different types of configurations for the transformed region and the basic transformation relations from a cartesian system to a general curvilinear system are given. The material of this paper is applicable to all types of coordinate system generation.
Evans, H.T.
1963-01-01
A review of the known crystal structures containing the uranyl ion shows that plane-pentagon coordination is equally as prevalent as plane-square or plane-hexagon. It is suggested that puckered-hexagon configurations of OH - or H2O about the uranyl group will tend to revert to plane-pentagon coordination. The concept of pentagonal coordination is invoked for possible explanations of the complex crystallography of the natural uranyl hydroxides and the unusual behavior of polynuclear ions in hydrolyzed uranyl solutions.
Data Assimilation by delay-coordinate nudging
NASA Astrophysics Data System (ADS)
Pazo, Diego; Lopez, Juan Manuel; Carrassi, Alberto
2016-04-01
A new nudging method for data assimilation, delay-coordinate nudging, is presented. Delay-coordinate nudging makes explicit use of present and past observations in the formulation of the forcing driving the model evolution at each time-step. Numerical experiments with a low order chaotic system show that the new method systematically outperforms standard nudging in different model and observational scenarios, also when using an un-optimized formulation of the delay-nudging coefficients. A connection between the optimal delay and the dominant Lyapunov exponent of the dynamics is found based on heuristic arguments and is confirmed by the numerical results, providing a guideline for the practical implementation of the algorithm. Delay-coordinate nudging preserves the easiness of implementation, the intuitive functioning and the reduced computational cost of the standard nudging, making it a potential alternative especially in the field of seasonal-to-decadal predictions with large Earth system models that limit the use of more sophisticated data assimilation procedures.
Enhancing healthcare sector coordination through infrastructure and logistics support.
Zoraster, Richard M
2010-01-01
The International Response to the 2004 Southeast Asia Tsunami was noted to have multiple areas of poor coordination, and in 2005, the "Health Cluster"approach to coordination was formulated. However, the 2010 Haiti response suggests that many of the same problems continue and that there are significant limitations to the cluster meetings. These limitations include the inconsistent attendance, poor dissemination of information, and perceived lack of benefit to providers. This article proposes that healthcare coordination would be greatly improved with logistical support, leading to improved efficiency and outcomes for those affected by disasters.
Coordinated planning for science in communist europe.
Jordan, L F
1967-02-17
The Council is not engaged in the supranational formulation of policy and planning on scientific research and technology, but has made considerable progress in coordinating research policies and plans on a limited number of scientific and technical problems of priority interest and of common concern to all members. The establishment of national science-planning institutions in CEMA countries and the adoption of a uniform approach to the formulation of national science policies and plans must be considered basic procedures for achieving international coordination of their efforts. The creation of organizational units within CEMA to deal specifically with the coordination of science policies and plans represents a strengthening of the institutional framework that is necessary for coordination of an internationally cooperative effort in research and technology. Moreover, CEMA's 1-year plan for science and technology has probably been of considerable value as a pilot project for the formulation of the research plan for 1966-70. The delineation of a limited number of important scientific and technical problems of common interest to the members, and the allocation of research projects to a country having the highest capability to conduct them, hold considerable promise for financial savings and for improved utilization of the limited scientific manpower and research facilities of the CEMA countries. While all these measures are significant in CEMA's attempt to improve coordination of science policy and planning, only time will enable true assessment of their effectiveness. The Council's scheme for the specialization of labor in research and technology has met and will undoubtedly continue to meet, considerable opposition by various segments of the scientific communities because of deep-rooted and long-standing national prejudices, and reluctance of vested interests to give up research activities in which they are interested and to which their professional futures are
A new formulation of hybrid/mixed finite element
NASA Technical Reports Server (NTRS)
Pian, T. H. H.; Kang, D.; Chen, D.-P.
1983-01-01
A new formulation of finite element method is accomplished by the Hellinger-Reissner principle for which the stress equilibrium conditions are not introduced initially but are brought-in through the use of additional internal displacement parameters. The method can lead to the same result as the assumed stress hybrid model. However, it is more general and more flexible. The use of natural coordinates for stress assumptions leads to elements which are less sensitive to the choice of reference coordinates. Numerical solutions by 3-D solid element indicate that more efficient elements can be constructed by assumed stresses which only partially satisfy the equilibrium conditions.
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Environmental Compliance Issue Coordination
An order to establish the Department of Energy (DOE) requirements for coordination of significant environmental compliance issues to ensure timely development and consistent application of Departmental environmental policy and guidance
Plutonium Immobilization Project Baseline Formulation
Ebbinghaus, B.
1999-02-01
A key milestone for the Immobilization Project (AOP Milestone 3.2a) in Fiscal Year 1998 (FY98) is the definition of the baseline composition or formulation for the plutonium ceramic form. The baseline formulation for the plutonium ceramic product must be finalized before the repository- and plant-related process specifications can be determined. The baseline formulation that is currently specified is given in Table 1.1. In addition to the baseline formulation specification, this report provides specifications for two alternative formulations, related compositional specifications (e.g., precursor compositions and mixing recipes), and other preliminary form and process specifications that are linked to the baseline formulation. The preliminary specifications, when finalized, are not expected to vary tremendously from the preliminary values given.
Abdollah, Firas; Cozzarini, Cesare; Suardi, Nazareno; Gallina, Andrea; Capitanio, Umberto; Bianchi, Marco; Tutolo, Manuela; Salonia, Andrea; La Macchia, Mariangela; Di Muzio, Nadia; Rigatti, Patrizio; Montorsi, Francesco; Briganti, Alberto
2012-06-01
Purpose: Previous studies have criticized the predicting ability of the Roach formula in assessing the risk of lymph node invasion (LNI) in contemporary patients with prostate cancer (PCa) due to a significant overestimation of LNI rates. However, all those studies included patients treated with limited pelvic lymph node dissection (PLND), which is associated with high rates of false negative findings. We hypothesized that the Roach formula is still an accurate tool for LNI predictions if an extended PLND (ePLND) is performed. Methods and Materials: We included 3,115 consecutive patients treated with radical prostatectomy and ePLND between 2000 and 2010 at a single tertiary referral center. Extended PLND consisted of removal of obturator, external iliac, and hypogastric lymph nodes. We externally validated the Roach formula by using the area under the receiver operating characteristics curve and calibration plot method. Moreover, we tested the performance characteristics of different formula-generated cutoff values ranging from 1% to 20%. Results: The accuracy of the Roach formula was 80.3%. The calibration showed only a minor underestimation of the LNI risk in high-risk patients (6.7%). According to the Roach formula, the use of 15% cut off would have allowed 74.2% (2,311/3,115) of patients to avoid nodal irradiation, while up to 32.7% (111/336) of all patients with LNI would have been missed. When the cut off was lowered to 6%, nodal treatment would have been spared in 1,541 (49.5%) patients while missing 41 LNI patients. The sensitivity, specificity, and negative predictive values associated with the 6% cut off were 87.9%, 54%, and 97.3%, respectively. Conclusions: The Roach formula is still accurate and does not overestimate the rate of LNI in contemporary prostate cancer patients if they are treated with ePLND. However, the recommended cut off of 15% would miss approximately one-third of patients with LNI. Based on our results, the cut off should be lowered to
Electrical conductive coordination polymers.
Givaja, Gonzalo; Amo-Ochoa, Pilar; Gómez-García, Carlos J; Zamora, Félix
2012-01-07
Coordination polymers are currently one of the hottest topics in Inorganic and Supramolecular Chemistry. This critical review summarizes the current state-of-the-art on electrical conductive coordination polymers (CPs), also named metal-organic frameworks (MOFs). The data were collected following two sort criteria of the CPs structure: dimensionality and bridging ligands (151 references). This journal is © The Royal Society of Chemistry 2012
Geometry optimization of periodic systems using internal coordinates.
Bucko, Tomás; Hafner, Jürgen; Angyán, János G
2005-03-22
An algorithm is proposed for the structural optimization of periodic systems in internal (chemical) coordinates. Internal coordinates may include in addition to the usual bond lengths, bond angles, out-of-plane and dihedral angles, various "lattice internal coordinates" such as cell edge lengths, cell angles, cell volume, etc. The coordinate transformations between Cartesian (or fractional) and internal coordinates are performed by a generalized Wilson B-matrix, which in contrast to the previous formulation by Kudin et al. [J. Chem. Phys. 114, 2919 (2001)] includes the explicit dependence of the lattice parameters on the positions of all unit cell atoms. The performance of the method, including constrained optimizations, is demonstrated on several examples, such as layered and microporous materials (gibbsite and chabazite) as well as the urea molecular crystal. The calculations used energies and forces from the ab initio density functional theory plane wave method in the projector-augmented wave formalism.
Explosive Formulation Code Naming SOP
Martz, H. E.
2014-09-19
The purpose of this SOP is to provide a procedure for giving individual HME formulations code names. A code name for an individual HME formulation consists of an explosive family code, given by the classified guide, followed by a dash, -, and a number. If the formulation requires preparation such as packing or aging, these add additional groups of symbols to the X-ray specimen name.
Nodal predictive error model and Bayesian approach for thermal diffusivity and heat source mapping
NASA Astrophysics Data System (ADS)
Massard, H.; Fudym, Olivier; Orlande, H. R. B.; Batsale, J. C.
2010-07-01
This article aims at solving a two-dimensional inverse heat conduction problem in order to retrieve both the thermal diffusivity and heat source field in a thin plate. A spatial random heat pulse is applied to the plate and the thermal response is analysed. The inverse approach is based on the minimisation of a nodal predictive error model, which yields a linear estimation problem. As a result of this approach, the sensitivity matrix is directly filled with experimental data, and thus is partially noisy. Bayesian estimators, such as the Maximum A Posteriori and a Markov Chain Monte Carlo approach (Metropolis-Hastings), are implemented and compared with the Ordinary Least Squares solution. Simulated temperature measurements are used in the inverse analysis. The nodal strategy relies on the availability of temperature measurements with fine spatial resolution and high frequency, typical of nowadays infrared cameras. The effects of both the measurement errors and of the model errors on the inverse problem solution are also analysed.
2012-01-01
Background Radiotherapy (RT) is widely used in the treatment of pancreatic cancer. Currently, recommendation has been given for the delineation of the clinical target volume (CTV) in adjuvant RT. Based on recently reviewed pathologic data, the aim of this study is to propose criteria for the CTV definition and delineation including elective nodal irradiation (ENI) in the preoperative and definitive treatment of pancreatic cancer. Methods The anatomical structures of interest, as well as the abdominal vasculature were identified on intravenous contrast-enhanced CT scans of two different patients with pancreatic cancer of the head and the body. To delineate the lymph node area, a margin of 10 mm was added to the arteries. Results We proposed a set of guidelines for elective treatment of high-risk nodal areas and CTV delineation. Reference CT images were provided. Conclusions The proposed guidelines could be used for preoperative or definitive RT for carcinoma of the head and body of the pancreas. Further clinical investigations are needed to validate the defined CTVs. PMID:22691275
Misalignment-induced nodal aberration fields in two-mirror astronomical telescopes.
Schmid, Tobias; Thompson, Kevin P; Rolland, Jannick P
2010-06-01
We present the effects of misalignments on the field dependence of the third-order aberration fields of traditional, two-mirror astronomical telescopes in the context of nodal aberration theory, which we believe is the most general and extensible framework for describing and improving on-station performance. While many of the advantages of nodal aberration theory, compared to other, often power series expansion-based descriptions of misalignment effects on aberrations, become particularly important when analyzing telescopes with more than two mirrors, or in the presence of figure errors; this paper aims to provide and demonstrate the fundamental concepts needed to fully describe the state of correction of misaligned two-mirror telescopes. Importantly, it is shown that the assumption that perfect performance on axis ensures a fully aligned telescope is false, and we demonstrate that if Ritchey-Chrétien telescopes are aligned for zero coma on axis as the sole criterion, formidable misalignments will likely remain, leading to image quality degradation, particularly beyond midfield caused by astigmatism with binodal field dependence (i.e., astigmatism goes to zero at two points in the field).
Vollmer, Robin T
2005-05-01
This article deals with and formalizes 2 notions common to the practice of pathology. The first is that the number of lymph nodes found positive for metastasis relates directly to the total number of lymph nodes examined. The second is that for any patient, there is a chance that the absence of lymph node metastases is a false-negative result. I introduce the Poisson probability density function to deal with the first notion and the Bayes probability rule to deal with the second. To illustrate the insight these 2 models provide, I apply them to data regarding lymph nodal metastases in malignant melanoma. In this preliminary study, the results of these 2 models correlate well with observed survival probabilities in patients with stage N0 melanoma and with observed rates of false-negative results in sentinel lymph node biopsy technology. With further development, the combination of these models should provide a way to estimate the probability of nodal metastasis when, in fact, none have been observed. Thus, these models might provide useful tools for evaluating patients with stage N0 malignant neoplasms.
Deserno, Willem M.L.L.G.; Debats, Oscar A.; Rozema, Tom; Fortuin, Ansje S.; Heesakkers, Roel A.M.; Hoogeveen, Yvonne; Peer, Petronella G.M.; Barentsz, Jelle O.; Lin, Emile N.J.T. van
2011-09-01
Purpose: To compare the nodal risk formula (NRF) as a predictor for lymph node (LN) metastasis in patients with prostate cancer with magnetic resonance lymphography (MRL) using Ultrasmall Super-Paramagnetic particles of Iron Oxide (USPIO) and with histology as gold standard. Methods and Materials: Logistic regression analysis was performed with the results of histopathological evaluation of the LN as dependent variable and the nodal risk according to the NRF and the result of MRL as independent input variables. Receiver operating characteristic (ROC) analysis was performed to assess the performance of the models. Results: The analysis included 375 patients. In the single-predictor regression models, the NRF and MRL results were both significantly (p <0.001) predictive of the presence of LN metastasis. In the models with both predictors included, NRF was nonsignificant (p = 0.126), but MRL remained significant (p <0.001). For NRF, sensitivity was 0.79 and specificity was 0.38; for MRL, sensitivity was 0.82 and specificity was 0.93. After a negative MRL result, the probability of LN metastasis is 4% regardless of the NRF result. After a positive MRL, the probability of having LN metastasis is 68%. Conclusions: MRL is a better predictor of the presence of LN metastasis than NRF. Using only the NRF can lead to a significant overtreatment on the pelvic LN by radiation therapy. When the MRL result is available, the NRF is no longer of added value.
Reflector modelling of small high leakage cores making use of multi-group nodal equivalence theory
Theron, S. A.; Reitsma, F.
2012-07-01
This research focuses on modelling reflectors in typical material testing reactors (MTRs). Equivalence theory is used to homogenise and collapse detailed transport solutions to generate equivalent nodal parameters and albedo boundary conditions for reflectors, for subsequent use in full core nodal diffusion codes. This approach to reflector modelling has been shown to be accurate for two-group large commercial light water reactor (LWR) analysis, but has not been investigated for MTRs. MTRs are smaller, with much larger leakage, environment sensitivity and multi-group spectrum dependencies than LWRs. This study aims to determine if this approach to reflector modelling is an accurate and plausible homogenisation technique for the modelling of small MTR cores. The successful implementation will result in simplified core models, better accuracy and improved efficiency of computer simulations. Codes used in this study include SCALE 6.1, OSCAR-4 and EQUIVA (the last two codes are developed and used at Necsa). The results show a five times reduction in calculational time for the proposed reduced reactor model compared to the traditional explicit model. The calculated equivalent parameters however show some sensitivity to the environment used to generate them. Differences in the results compared to the current explicit model, require more careful investigation including comparisons with a reference result, before its implementation can be recommended. (authors)
Successful catheter ablation of a slow AV-nodal pathway from the left posteroseptal region.
Wieczorek, M; Höltgen, R; Djajadisastra, I
2005-08-01
We present the case of a 44 year old woman with recurrent episodes of supraventricular tachycardia due to AV-nodal reentry (AVNRT). She was refractory to conventional medical treatment and referred to our hospital with the view to catheter ablation of the slow AV-nodal pathway. AVNRT of the common type was easily induced performing stimulation from the high right atrium and proximal coronary sinus. Other forms of supraventricular tachycardia were definitely ruled out during further electrophysiologic study. Repetitive RF applications around the right posteroseptal region failed to cure the tachycardia which remained inducible with a typical jump in the AH interval. Extensive RF applications from posteroinferior to the midseptum including the area of the proximal coronary sinus and its os were ineffective as well.AVNRT was transiently but reproducibly eliminated while burns were applied to the high midseptum but AVNRT reoccured within 20 minutes. Finally after retrograde passage of the aortic valve with a 4 mm tip ablation catheter, RF was applied to the left postero to midseptal region. An accelerated junctional rhythm was immediately observed and AVNRT remained non-inducible from that time onwards. It is concluded that an atypical posterior extension of the AV node with predominant leftatrial course might be responsible for this unusual success of slow pathway elimination from left posteroseptal.
Topological nodal points in two coupled Su-Schrieffer-Heeger chains
NASA Astrophysics Data System (ADS)
Li, C.; Lin, S.; Zhang, G.; Song, Z.
2017-09-01
We study a two coupled Su-Schrieffer-Heeger (SSH) chains system, which is shown to contain rich quantum phases associated with topological invariants protected by symmetries. In the weak coupling region, the system supports two nontrivial topological insulating phases, characterized by winding number N =±1 , and two types of edge states. The boundary between the two topological phases arises from two band closing points, which exhibit topological characteristics in one-dimensional k space. By mapping Bloch states on a vector field in k space, the band degenerate points correspond to a pair of kinks of the field, with opposite topological charges. Two topological nodal points move and merge as the interchain coupling strength varies. This topological invariant is protected by the translational and inversion symmetries, rather than the antiunitary operation. Furthermore, we find that when a pair of nodal points is created, a second order quantum phase transition (QPT) occurs, associating with a gap closing and spontaneously symmetry breaking. This simple model demonstrates several central concepts in the field of quantum materials and provides a theoretical connection between them.
Cooperative Wnt-Nodal Signals Regulate the Patterning of Anterior Neuroectoderm
Yaguchi, Junko; Takeda, Noriyo; Inaba, Kazuo; Yaguchi, Shunsuke
2016-01-01
When early canonical Wnt is experimentally inhibited, sea urchin embryos embody the concept of a Default Model in vivo because most of the ectodermal cell fates are specified as anterior neuroectoderm. Using this model, we describe here how the combination of orthogonally functioning anteroposterior Wnt and dorsoventral Nodal signals and their targeting transcription factors, FoxQ2 and Homeobrain, regulates the precise patterning of normal neuroectoderm, of which serotonergic neurons are differentiated only at the dorsal/lateral edge. Loss-of-function experiments revealed that ventral Nodal is required for suppressing the serotonergic neural fate in the ventral side of the neuroectoderm through the maintenance of foxQ2 and the repression of homeobrain expression. In addition, non-canonical Wnt suppressed homeobrain in the anterior end of the neuroectoderm, where serotonergic neurons are not differentiated. Canonical Wnt, however, suppresses foxQ2 to promote neural differentiation. Therefore, the three-dimensionally complex patterning of the neuroectoderm is created by cooperative signals, which are essential for the formation of primary and secondary body axes during embryogenesis. PMID:27101101
The lunar nodal tide and the distance to tne Moon during the Precambrian era
NASA Technical Reports Server (NTRS)
Walker, J. C. G.; Zahnle, K. J.
1986-01-01
The origin and early evolution of life on Earth occurred under physical and chemical conditions distinctly different from those of the present day. The broad goal of this research program is to characterize these conditions. One aspect involves the dynamics of the Earth-Moon system, the distance of the Moon from the Earth, and the length of the day. These have evolved during the course of Earth history as a result of the dissipation of tidal energy. As the moon has receded the amplitude of oceanic tides has decreased while the increasing length of the day should have influenced climate and the circulation of atmosphere and ocean. A 23.3 year periodicity preserved in a 2500 million year old banded iron-formation was interpreted as reflecting the climatic influence of the lunar nodal tide. The corresponding lunar distance would then have been approx. 52 Earth radii. The influence of the lunar nodal tide is also apparent in rocks with an age of 680 million years B.P. The derived value for lunar distance 2500 million years ago is the only datum on the dynamics of the Earth-Moon system during the Precambrian era of Earth history. The implied development of Precambrian tidal friction is in accord with more recent paleontological evidence as well as the long term stability of the lunar orbit.
Conservation defines functional motifs in the squint/nodal-related 1 RNA dorsal localization element
Gilligan, Patrick C.; Kumari, Pooja; Lim, Shimin; Cheong, Albert; Chang, Alex; Sampath, Karuna
2011-01-01
RNA localization is emerging as a general principle of sub-cellular protein localization and cellular organization. However, the sequence and structural requirements in many RNA localization elements remain poorly understood. Whereas transcription factor-binding sites in DNA can be recognized as short degenerate motifs, and consensus binding sites readily inferred, protein-binding sites in RNA often contain structural features, and can be difficult to infer. We previously showed that zebrafish squint/nodal-related 1 (sqt/ndr1) RNA localizes to the future dorsal side of the embryo. Interestingly, mammalian nodal RNA can also localize to dorsal when injected into zebrafish embryos, suggesting that the sequence motif(s) may be conserved, even though the fish and mammal UTRs cannot be aligned. To define potential sequence and structural features, we obtained ndr1 3′-UTR sequences from approximately 50 fishes that are closely, or distantly, related to zebrafish, for high-resolution phylogenetic footprinting. We identify conserved sequence and structural motifs within the zebrafish/carp family and catfish. We find that two novel motifs, a single-stranded AGCAC motif and a small stem-loop, are required for efficient sqt RNA localization. These findings show that comparative sequencing in the zebrafish/carp family is an efficient approach for identifying weak consensus binding sites for RNA regulatory proteins. PMID:21149265
Oyster Creek cycle 10 nodal model parameter optimization study using PSMS
Dougher, J.D.
1987-01-01
The power shape monitoring system (PSMS) is an on-line core monitoring system that uses a three-dimensional nodal code (NODE-B) to perform nodal power calculations and compute thermal margins. The PSMS contains a parameter optimization function that improves the ability of NODE-B to accurately monitor core power distributions. This functions iterates on the model normalization parameters (albedos and mixing factors) to obtain the best agreement between predicted and measured traversing in-core probe (TIP) reading on a statepoint-by-statepoint basis. Following several statepoint optimization runs, an average set of optimized normalization parameters can be determined and can be implemented into the current or subsequent cycle core model for on-line core monitoring. A statistical analysis of 19 high-power steady-state state-points throughout Oyster Creek cycle 10 operation has shown a consistently poor virgin model performance. The normalization parameters used in the cycle 10 NODE-B model were based on a cycle 8 study, which evaluated only Exxon fuel types. The introduction of General Electric (GE) fuel into cycle 10 (172 assemblies) was a significant fuel/core design change that could have altered the optimum set of normalization parameters. Based on the need to evaluate a potential change in the model normalization parameters for cycle 11 and in an attempt to account for the poor cycle 10 model performance, a parameter optimization study was performed.
Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates
Harrison, N.; Ramshaw, B. J.; Shekhter, A.
2015-01-01
The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whose primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport, and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y PMID:26039222
Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates
Harrison, N.; Ramshaw, B. J.; Shekhter, A.
2015-06-03
The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whosemore » primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport, and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y« less
A generalized framework for nodal first derivative summation-by-parts operators
NASA Astrophysics Data System (ADS)
Del Rey Fernández, David C.; Boom, Pieter D.; Zingg, David W.
2014-06-01
A generalized framework is presented that extends the classical theory of finite-difference summation-by-parts (SBP) operators to include a wide range of operators, where the main extensions are (i) non-repeating interior point operators, (ii) nonuniform nodal distribution in the computational domain, (iii) operators that do not include one or both boundary nodes. Necessary and sufficient conditions are proven for the existence of nodal approximations to the first derivative with the SBP property. It is proven that the positive-definite norm matrix of each SBP operator must be associated with a quadrature rule; moreover, given a quadrature rule there exists a corresponding SBP operator, where for diagonal-norm SBP operators the weights of the quadrature rule must be positive. The generalized framework gives a straightforward means of posing many known approximations to the first derivative as SBP operators; several are surveyed, such as discontinuous Galerkin discretizations based on the Legendre-Gauss quadrature points, and shown to be SBP operators. Moreover, the new framework provides a method for constructing SBP operators by starting from quadrature rules; this is illustrated by constructing novel SBP operators from known quadrature rules. To demonstrate the utility of the generalization, the Legendre-Gauss and Legendre-Gauss-Radau quadrature points are used to construct SBP operators that do not include one or both boundary nodes.
Nodal mantle cell lymphoma: a descriptive study from a tertiary care center in South India.
Roy, Arun; Kar, Rakhee; Basu, Debdatta
2013-01-01
Mantle cell lymphoma (MCL) is a type of B-cell non-Hodgkin lymphoma (NHL) with distinctive morphologic, immunophenotypic and a characteristic cytogenetic abnormality, the t(11;14)(q13;q32) and overexpression of cyclin D1. The common histologic features include effaced lymphoid architecture by a monomorphic lymphoid population with a vaguely nodular, diffuse or mantle zone growth pattern. The classic cytomorphologic features include small to medium sized lymphoid cells with irregular nuclear contours and scanty cytoplasm, closely resembling centrocytes. This retrospective study comprises 13 cases of MCL over a period of 5½ years in our department, comprising 4% of all nodal NHL diagnosed. All cases were diagnosed on lymph node biopsy. The mean age of the presentation was 57 years. There was a male preponderance (M:F = 2.25:1). The disease was nodal in all cases. Most patients (84.5%) had generalized lymphadenopathy and/or hepatosplenomegaly. Bone marrow involvement was seen in 81.8% of cases. Three cases showed a nodular pattern on lymph node biopsy while remaining ten had a diffuse pattern. Immunophenotyping showed positivity for CD20, CD5 and cyclin D1 and CD23 negativity. Despite certain morphological similarity to other low-grade/intermediate-grade lymphomas, MCL has a characteristic appearance of its own. Since it is more aggressive than other low-grade lymphomas it needs to be accurately diagnosed.
Slow pathway modification in patients presenting with only two consecutive AV nodal echo beats.
Wegner, Felix K; Silvano, Maria; Bögeholz, Nils; Leitz, Patrick R; Frommeyer, Gerrit; Dechering, Dirk G; Zellerhoff, Stephan; Kochhäuser, Simon; Lange, Philipp S; Köbe, Julia; Wasmer, Kristina; Mönnig, Gerold; Eckardt, Lars; Pott, Christian
2017-02-01
Slow pathway modification (SPM) is the therapy of choice for AV-nodal reentry tachycardia (AVNRT). When AVNRT is not inducible, empirical ablation can be considered, however, the outcome in patients with two AV nodal echo beats (AVNEBs) is unknown. Out of a population of 3003 patients who underwent slow pathway modification at our institution between 1993 and 2013, we retrospectively included 32 patients with a history of symptomatic tachycardia, lack of paroxysmal supraventricular tachycardia (pSVT) inducibility but occurrence of two AVNEBs. pSVT documentation by electrocardiography (ECG) was present in 20 patients. The procedural endpoint was inducibility of less than two AVNEBs. This was reached in 31 (97%) patients. Long-term success was assessed by a telephone questionnaire (follow-up time 63±9 months). A total 94% of the patients benefited from the procedure (59% freedom from symptoms; 34% improvement in symptoms). Among those patients in whom ECG documentation was not present, 100% benefited (58% freedom from symptoms, 42% improvement). This is the first collective analysis of a group of patients presenting with symptoms of pSVT and inducibility of only two AVNEBs. Procedural success and clinical long-term follow-up were in the range of the reported success rates of slow pathway modification of inducible AVNRT, independent of whether ECG documentation was present. Thus, SPM is a safe and effective therapy in patients with two AVNEBs. Copyright © 2016. Published by Elsevier Ltd.
Inland waterway ports nodal attraction indices relevant in development strategies on regional level
NASA Astrophysics Data System (ADS)
Dinu, O.; Burciu, Ş.; Oprea, C.; Ilie, A.; Rosca, M.
2016-08-01
Present paper aims to propose a set of ranking indices and related criteria, concerning mainly spatial analysis, for the inland waterway port, with special view on inland ports of Danube. Commonly, the attraction potential of a certain transport node is assessed by its spatial accessibility indices considering both spatial features of the location provided by the networks that connect into that node and its economic potential defining the level of traffic flows depending on the economic centers of its hinterland. Paper starts with a overview of the critical needs that are required for potential sites to become inland waterway ports and presents nodal functions that coexist at different levels, leading to a port hierarchy from the points of view of: capacity, connection to hinterland, traffic structure and volume. After a brief review of the key inland waterway port ranking criterion, a selection of nodal attraction measures is made. Particular considerations for the Danube inland port case follows proposed methodology concerning indices of performance for network scale and centrality. As expected, the shorter the distance from an inland port to the nearest access point the greater accessibility. Major differences in ranking, dependent on selected criterion, were registered.
An Otx/Nodal Regulatory Signature for Posterior Neural Development in Ascidians
Roure, Agnès; Lemaire, Patrick; Darras, Sébastien
2014-01-01
In chordates, neural induction is the first step of a complex developmental process through which ectodermal cells acquire a neural identity. In ascidians, FGF-mediated neural induction occurs at the 32-cell stage in two blastomere pairs, precursors respectively of anterior and posterior neural tissue. We combined molecular embryology and cis-regulatory analysis to unveil in the ascidian Ciona intestinalis the remarkably simple proximal genetic network that controls posterior neural fate acquisition downstream of FGF. We report that the combined action of two direct FGF targets, the TGFβ factor Nodal, acting via Smad- and Fox-binding sites, and the transcription factor Otx suffices to trigger ascidian posterior neural tissue formation. Moreover, we found that this strategy is conserved in the distantly related ascidian Phallusia mammillata, in spite of extreme sequence divergence in the cis-regulatory sequences involved. Our results thus highlight that the modes of gene regulatory network evolution differ with the evolutionary scale considered. Within ascidians, developmental regulatory networks are remarkably robust to genome sequence divergence. Between ascidians and vertebrates, major fate determinants, such as Otx and Nodal, can be co-opted into different networks. Comparative developmental studies in ascidians with divergent genomes will thus uncover shared ascidian strategies, and contribute to a better understanding of the diversity of developmental strategies within chordates. PMID:25121599
Nodal/Activin Pathway is a Conserved Neural Induction Signal in Chordates.
Le Petillon, Yann; Luxardi, Guillaume; Scerbo, Pierluigi; Cibois, Marie; Leon, Anthony; Subirana, Lucie; Irimia, Manuel; Kodjabachian, Laurent; Escriva, Hector; Bertrand, Stephanie
2017-08-01
Neural induction is the process through which pluripotent cells are committed to a neural fate. This first step of Central Nervous System formation is triggered by the "Spemann organizer" in amphibians and by homologous embryonic regions in other vertebrates. Studies in classical vertebrate models have produced contrasting views about the molecular nature of neural inducers and no unifying scheme could be drawn. Moreover, how this process evolved in the chordate lineage remains an unresolved issue. In this work, by using graft and micromanipulation experiments, we definitively establish that the dorsal blastopore lip of the cephalochordate amphioxus is homologous to the vertebrate organizer and is able to trigger the formation of neural tissues in a host embryo. In addition, we demonstrate that Nodal/Activin is the main signal eliciting neural induction in amphioxus, and that it also functions as a bona fide neural inducer in the classical vertebrate model Xenopus. Altogether, our results allow us to propose that Nodal/Activin was a major player of neural induction in the ancestor of chordates. This study further reveals the diversity of neural inducers deployed during chordate evolution and advocates against a universally conserved molecular explanation for this process.
Observation of topological nodal fermion semimetal phase in ZrSiS
NASA Astrophysics Data System (ADS)
Neupane, Madhab; Belopolski, Ilya; Hosen, M. Mofazzel; Sanchez, Daniel S.; Sankar, Raman; Szlawska, Maria; Xu, Su-Yang; Dimitri, Klauss; Dhakal, Nagendra; Maldonado, Pablo; Oppeneer, Peter M.; Kaczorowski, Dariusz; Chou, Fangcheng; Hasan, M. Zahid; Durakiewicz, Tomasz
2016-05-01
Unveiling new topological phases of matter is one of the current objectives in condensed matter physics. Recent experimental discoveries of Dirac and Weyl semimetals prompt the search for other exotic phases of matter. Here we present a systematic angle-resolved photoemission spectroscopy study of ZrSiS, a prime topological nodal semimetal candidate. Our wider Brillouin zone (BZ) mapping shows multiple Fermi surface pockets such as the diamond-shaped Fermi surface, elliptical-shaped Fermi surface, and a small electron pocket encircling at the zone center (Γ ) point, the M point, and the X point of the BZ, respectively. We experimentally establish the spinless nodal fermion semimetal phase in ZrSiS, which is supported by our first-principles calculations. Our findings evidence that the ZrSiS-type of material family is a new platform on which to explore exotic states of quantum matter; these materials are expected to provide an avenue for engineering two-dimensional topological insulator systems.
NASA Astrophysics Data System (ADS)
Laundal, K. M.; Richmond, A. D.
2017-03-01
Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.
Mapping brains without coordinates
Kötter, Rolf; Wanke, Egon
2005-01-01
Brain mapping has evolved considerably over the last century. While most emphasis has been placed on coordinate-based spatial atlases, coordinate-independent parcellation-based mapping is an important technique for accessing the multitude of structural and functional data that have been reported from invasive experiments, and provides for flexible and efficient representations of information. Here, we provide an introduction to motivations, concepts, techniques and implications of coordinate-independent mapping of microstructurally or functionally defined brain structures. In particular, we explain the problems of constructing mapping paths and finding adequate heuristics for their evaluation. We then introduce the three auxiliary concepts of acronym-based mapping (AM), of a generalized hierarchy (GM ontology), and of a topographically oriented regional map (RM) with adequate granularity for mapping between individual brains with different cortical folding and between humans and non-human primates. Examples from the CoCoMac database of primate brain connectivity demonstrate how these concepts enhance coordinate-independent mapping based on published relational statements. Finally, we discuss the strengths and weaknesses of spatial coordinate-based versus coordinate-independent microstructural brain mapping and show perspectives for a wider application of parcellation-based approaches in the integration of multi-modal structural, functional and clinical data. PMID:15971361
Elizalde, J; Lorente, M
2006-01-01
The progressive incorporation of organ transplants as a therapeutic resource resulted in organisational adaptation and overall transplant management, leading to the emergence of the figure of the transplant coordinator in the mid-1980s. In Spain, the National Organisation of Transplants (Organización Nacional de Transplantes - ONT) was created, establishing a system - called the "Spanish model" - based on a network of coordinators at three levels: national, the autonomous community and the hospital. This organisational structure is a point of reference at the world level. The prevalence of the Intensive Medicine specialisation amongst hospital transplant coordinators is remarkable. The majority of organs proceed from brain-dead patients with beating hearts and this requires the infrastructure offered by intensive care units. The functions of the coordinator can be summarised in guaranteeing a synchrony of all the elements and teams that come together in an organisational chain that has come to be called the "process of donation". Schematically, the crucial points that the hospital coordinator develops are the following: - Detection of the potential donor. - Maintenance of the donor. - Diagnosis of brain death. - Family consent. - Preparation of the hospital logistics. - Helping the relatives. - Direct involvement in the Program of Guarantee of Quality. - Person of reference in any activity related to the transplant. It would be desirable to achieve the creation of transplant coordination teams, with univocal messages, professionalism and a permanent input of the so-called "human factor", which is so necessary and also so close to the transplant world.
NASA Astrophysics Data System (ADS)
Laundal, K. M.; Richmond, A. D.
2016-07-01
Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.
Valence, Covalence, Hypervalence, Oxidation State, and Coordination Number
ERIC Educational Resources Information Center
Smith, Derek W.
2005-01-01
Valence as a numerical measure of an atom's combining power, expressed by the number of bonds it forms in a molecular formulation of the compound in question, was unable to cope with coordination compounds. The covalence of an atom is the nearest model equivalent, but is subject to ambiguity since it often depends on which bonding model is being…
Modelling and control of two coordinated robot arms
NASA Technical Reports Server (NTRS)
Tarn, T. J.; Yun, X.; Bejczy, A. K.
1988-01-01
Two coordinated robot arms are modeled by considering the two arms as working on the same object simultaneously and as a closed kinematic chain. In both formulations, a novel dynamic control method is used which is based on feedback linearization and simultaneous output decoupling.
Nonrecursive formulations of multibody dynamics and concurrent multiprocessing
NASA Technical Reports Server (NTRS)
Kurdila, Andrew J.; Menon, Ramesh
1993-01-01
Since the late 1980's, research in recursive formulations of multibody dynamics has flourished. Historically, much of this research can be traced to applications of low dimensionality in mechanism and vehicle dynamics. Indeed, there is little doubt that recursive order N methods are the method of choice for this class of systems. This approach has the advantage that a minimal number of coordinates are utilized, parallelism can be induced for certain system topologies, and the method is of order N computational cost for systems of N rigid bodies. Despite the fact that many authors have dismissed redundant coordinate formulations as being of order N(exp 3), and hence less attractive than recursive formulations, we present recent research that demonstrates that at least three distinct classes of redundant, nonrecursive multibody formulations consistently achieve order N computational cost for systems of rigid and/or flexible bodies. These formulations are as follows: (1) the preconditioned range space formulation; (2) penalty methods; and (3) augmented Lagrangian methods for nonlinear multibody dynamics. The first method can be traced to its foundation in equality constrained quadratic optimization, while the last two methods have been studied extensively in the context of coercive variational boundary value problems in computational mechanics. Until recently, however, they have not been investigated in the context of multibody simulation, and present theoretical questions unique to nonlinear dynamics. All of these nonrecursive methods have additional advantages with respect to recursive order N methods: (1) the formalisms retain the highly desirable order N computational cost; (2) the techniques are amenable to concurrent simulation strategies; (3) the approaches do not depend upon system topology to induce concurrency; and (4) the methods can be derived to balance the computational load automatically on concurrent multiprocessors. In addition to the presentation of
NASA Astrophysics Data System (ADS)
Ahn, Kyo-Hoon; Lee, Kwan-Woo; Pickett, Warren E.
2015-09-01
NbP is one member of a new class of nodal loop semimetals characterized by the cooperative effects of spin-orbit coupling (SOC) and a lack of inversion center. Here transport and spectroscopic properties of NbP are evaluated using density functional theory methods. SOC together with the lack of inversion symmetry splits degeneracies, giving rise to "Russian doll nested" Fermi surfaces containing 4 ×10-4 electron (hole) carriers/f.u. Due to the modest SOC strength in Nb, the Fermi surfaces map out the Weyl nodal loops. Calculated structure around T*≈100 K in transport properties reproduces well the observed transport behavior only when SOC is included, attesting to the precision of the (delicate) calculations and the stoichiometry of the samples. Low-energy collective electron-hole excitations (plasmons) in the 20-60 meV range result from the nodal loop splitting.
NASA Astrophysics Data System (ADS)
Das, T.; Figueira de Morisson Faria, C.
2016-08-01
We analyze the imprint of nodal planes in high-order-harmonic spectra from aligned diatomic molecules in intense laser fields whose components exhibit orthogonal polarizations. We show that the typical suppression in the spectra associated to nodal planes is distorted, and that this distortion can be employed to map the electron's angle of return to its parent ion. This investigation is performed semianalytically at the single-molecule response and single-active orbital level, using the strong-field approximation and the steepest descent method. We show that the velocity form of the dipole operator is superior to the length form in providing information about this distortion. However, both forms introduce artifacts that are absent in the actual momentum-space wave function. Furthermore, elliptically polarized fields lead to larger distortions in comparison to two-color orthogonally polarized fields. These features are investigated in detail for O2, whose highest occupied molecular orbital provides two orthogonal nodal planes.
Baseline LAW Glass Formulation Testing
Kruger, Albert A.; Mooers, Cavin; Bazemore, Gina; Pegg, Ian L.; Hight, Kenneth; Lai, Shan Tao; Buechele, Andrew; Rielley, Elizabeth; Gan, Hao; Muller, Isabelle S.; Cecil, Richard
2013-06-13
The major objective of the baseline glass formulation work was to develop and select glass formulations that are compliant with contractual and processing requirements for each of the LAW waste streams. Other objectives of the work included preparation and characterization of glasses with respect to the properties of interest, optimization of sulfate loading in the glasses, evaluation of ability to achieve waste loading limits, testing to demonstrate compatibility of glass melts with melter materials of construction, development of glass formulations to support ILAW qualification activities, and identification of glass formulation issues with respect to contract specifications and processing requirements.
Lithography overlay controller formulation
NASA Astrophysics Data System (ADS)
Bode, Christopher A.; Toprac, Anthony J.; Edwards, Richard D.; Edgar, Thomas F.
2000-08-01
Lithography overlay refers to the measurement of the alignment of successive patterns within the manufacture of semiconductor devices. Control of overlay has become of great importance in semiconductor manufacturing, as the tolerance for overlay error is continually shrinking in order to manufacture next-generation semiconductor products. Run-to-run control has become an attractive solution to many control problems within the industry, including overlay. The term run-to-run control refers to any automated procedure whereby recipe settings are updated between successive process runs in order to keep the process under control. The following discussion will present the formulation of such a controller by examining control of overlay. A brief introduction of overlay will be given, highlighting the control challenge overlay presents. A data management methodology that groups like processes together in order to improve controllability, referred to as control threads, will then be presented. Finally, a discussion of linear model predictive control will show its utility in feedback run-to-run control.
Development of a standing-wave fluorescence microscope with high nodal plane flatness.
Freimann, R; Pentz, S; Hörler, H
1997-09-01
This article reports about the development and application of a standing-wave fluorescence microscope (SWFM) with high nodal plane flatness. As opposed to the uniform excitation field in conventional fluorescence microscopes as SWFM uses a standing-wave pattern of laser light. This pattern consists of alternating planar nodes and antinodes. By shifting it along the axis of the microscope a set of different fluorescent structures can be distinguished. Their axial separation may just be a fraction of a wavelength so that an SWFM allows distinction of structures which would appear axially unresolved in a conventional or confocal fluorescence microscope. An SWFM is most powerful when the axial extension of the specimen is comparable to the wavelength of light. Otherwise several planes are illuminated simultaneously and their separation is hardly feasible. The objective of this work was to develop a new SWFM instrument which allows standing-wave fluorescence microscopy with controlled high nodal plane flatness. Earlier SWFMs did not allow such a controlled flatness, which impeded image interpretation and processing. Another design goal was to build a compact, easy-to-use instrument to foster a more widespread use of this new technique. The instrument developed uses a green-emitting helium-neon laser as the light source, a piezoelectric movable beamsplitter to generate two mutually coherent laser beams of variable relative phase and two single-mode fibres to transmit these beams to the microscope. Each beam is passed on to the specimen by a planoconvex lens and an objective lens. The only reflective surface whose residual curvature could cause wavefront deformations is a dichroic beamsplitter. Nodal plane flatness is controlled via interference fringes by a procedure which is similar to the interferometric test of optical surfaces. The performance of the instrument was tested using dried and fluorescently labelled cardiac muscle cells of rats. The SWFM enabled the
NASA Astrophysics Data System (ADS)
Cao, Meng
The goal of this dissertation is to develop a generally covariant Hamiltonian approach to the generalized harmonic formulation of general relativity. As en route investigations, an important class of coordinate transformations in the context of the 3 + 1 decomposition, foliation preserving transformations, is defined; transformation rules of various 3 + 1 decomposition variables under this change of coordinates are investigated; the notion of covariant time derivative under foliation preserving transformations is defined; gauge conditions of various numerical relativity formulations are rewritten in generally covariant form. The Hamiltonian formulation of the generalized harmonic system is defined in the latter part of this dissertation. With the knowledge of covariant time derivative, the Hamiltonian formulation is extended to achieve general covariance. The Hamiltonian formulation is further proved to be symmetric hyperbolic.
MCC level C formulation requirements. Entry guidance and entry autopilot, optional TAEM targeting
NASA Technical Reports Server (NTRS)
Harpold, J. C.
1980-01-01
The level C software formulations requirements for the entry guidance and the simplified autopilot to be used by the Mission Control Center (MCC) entry processor are presented. The modifications required to functionally simulate optional Terminal Area Energy Management (TAEM) targeting capability (OTT) are incorporated. Implementation of this logic in the MCC must be coordinated with flight software OTT implementation and MCC TAEM guidance OTT. The entry guidance logic is based on the orbiter avionics entry guidance software. Descriptions of the entry guidance detailed formulation requirements, the detailed autopilot formulation requirements, and the targeting routine are given. Also included are a definition of coordinate systems, a list of parameter definitions for the software formulations, and a set of formulation flow charts.
NASA Astrophysics Data System (ADS)
Agosta, E.
2013-05-01
The present work will show for first time some statistical evidences that the lunar nodal cycle can influence the low-frequency variability of summer rainfalls in the plains to the east of subtropical Andes, a region known as 'Nuevo Cuyo' (NC) in South America. The link can be established through the sea surface temperature (SST) modulation that is induced by the nodal amplitudes of diurnal tides over the southwestern South Atlatnci (SWSA) region. In years of strong (weak) diurnal tides, nodal tide-induced diapycnical mixing makes SST cooler (warmer) that are accompanied by negative (positive) sea level pressure (SLP) anomalies affecting the mid-latitudes low-level tropospheric circulation. The SST variations would presumably affect the lower tropospheric baroclinicity in the surroundings of the Malvinas/Falklands Islands in the SWSA, which in turn would induce shifts of mid-latitude stormtracks. Tropospheric circulation anomalies being located over the SWSA directly affect the interannual variability of summer rainfalls in NC. It is further shown that such an influence can be extended to the bidecadal variability observed in the summer rainfalls owing to the nodal modulation effect. The identification of the nodal periodicity in the NC summer rainfall variability is statistically robust. Although the 1976/77 climate shift has mitigated the bidecadal component of the summer rainfalls until the early 2000s, the nodal cycle has always been present. Hence it could improve the interdecadal predictability of the mean conditions of summer rainfalls and of those socio-economic variables being sensitive to precipitation such as grape yield in the Mendoza Province.
Balch, Charles M.; Gershenwald, Jeffrey E.; Soong, Seng-jaw; Thompson, John F.; Ding, Shouluan; Byrd, David R.; Cascinelli, Natale; Cochran, Alistair J.; Coit, Daniel G.; Eggermont, Alexander M.; Johnson, Timothy; Kirkwood, John M.; Leong, Stanley P.; McMasters, Kelly M.; Mihm, Martin C.; Morton, Donald L.; Ross, Merrick I.; Sondak, Vernon K.
2010-01-01
Purpose To determine the survival rates and independent predictors of survival using a contemporary international cohort of patients with stage III melanoma. Patients and Methods Complete clinicopathologic and follow-up data were available for 2,313 patients with stage III disease in an updated and expanded American Joint Committee on Cancer (AJCC) melanoma staging database. Kaplan-Meier and Cox multivariate survival analyses were performed. Results Among all 2,313 patients with stage III disease, 81% had micrometastases, and 19% had clinically detectable macrometastases. The 5-year overall survival was 63%; it was 67% for patients with nodal micrometastases, and it was 43% for those with nodal macrometastases (P < .001). Tremendous heterogeneity in survival was observed, particularly in the microscopically detected nodal metastasis subset (from 23% to 87% for 5-year survival). Multivariate analysis demonstrated that in patients with nodal micrometastases, number of tumor-containing lymph nodes, primary tumor thickness, patient age, ulceration, and anatomic site of the primary independently predicted survival (all P < .01). When added to the model, primary tumor mitotic rate was the second-most powerful predictor of survival after the number of tumor-containing nodes. In contrast, for patients with nodal macrometastases, the number of tumor-containing nodes, primary ulceration, and patient age independently predicted survival (P < .01). Conclusion In this multi-institutional analysis, we demonstrated remarkable heterogeneity of prognosis among patients with stage III melanoma, especially among those with nodal micrometastases. These results should be incorporated into the design and interpretation of future clinical trials involving patients with stage III melanoma. PMID:20368546
Young, Amy V.; Wortham, Angela; Wernick, Iddo; Evans, Andrew; Ennis, Ronald D.
2011-03-01
Purpose: Accurate target delineation of the nodal volumes is essential for three-dimensional conformal and intensity-modulated radiotherapy planning for endometrial cancer adjuvant therapy. We hypothesized that atlas-based segmentation ('autocontouring') would lead to time savings and more consistent contours among physicians. Methods and Materials: A reference anatomy atlas was constructed using the data from 15 postoperative endometrial cancer patients by contouring the pelvic nodal clinical target volume on the simulation computed tomography scan according to the Radiation Therapy Oncology Group 0418 trial using commercially available software. On the simulation computed tomography scans from 10 additional endometrial cancer patients, the nodal clinical target volume autocontours were generated. Three radiation oncologists corrected the autocontours and delineated the manual nodal contours under timed conditions while unaware of the other contours. The time difference was determined, and the overlap of the contours was calculated using Dice's coefficient. Results: For all physicians, manual contouring of the pelvic nodal target volumes and editing the autocontours required a mean {+-} standard deviation of 32 {+-} 9 vs. 23 {+-} 7 minutes, respectively (p = .000001), a 26% time savings. For each physician, the time required to delineate the manual contours vs. correcting the autocontours was 30 {+-} 3 vs. 21 {+-} 5 min (p = .003), 39 {+-} 12 vs. 30 {+-} 5 min (p = .055), and 29 {+-} 5 vs. 20 {+-} 5 min (p = .0002). The mean overlap increased from manual contouring (0.77) to correcting the autocontours (0.79; p = .038). Conclusion: The results of our study have shown that autocontouring leads to increased consistency and time savings when contouring the nodal target volumes for adjuvant treatment of endometrial cancer, although the autocontours still required careful editing to ensure that the lymph nodes at risk of recurrence are properly included in the target
Tracking a maneuvering target in spherical coordinates
NASA Astrophysics Data System (ADS)
Douglas, Andrew P.; Blanchard, Jeffrey A.; Grabbe, Michael T.
2003-08-01
This paper presents an Extended Kalman Filter for tracking a maneuvering target, where the kinematics of a typical target aircraft maneuver have been incorporated into the filter state equations. Such a formulation allows the target's motion to be accurately determined through estimation of heading and lateral acceleration. This is an improvement over the the typical approach of modeling target motion with acceleration terms represented by random processes, such as that used in the Singer model. In the following pages, a three-dimensional target maneuver model is formulated in conjunction with the kinematic equations of a sensor tracking a target in spherical coordinates. Three degree-of-freedom simulation results of the proposed filter, simplified for planar target maneuvers, are compared to a filter modeling target motion with the Singer model.
NASA Astrophysics Data System (ADS)
Hurd, O.; Zoback, M. D.
2011-12-01
In this study we revisit the question of slip on faults in the New Madrid seismic zone in the context of the regional stress field. Specifically, we utilize newly available data to investigate whether fault slip is compatible with the regional stress field and laboratory-determined coefficients of friction (as originally argued by M.D. Zoback and M.L. Zoback, Science, 1981) or if there is evidence for either local sources of stress or anomalously low fault strength. Ten new, well-constrained earthquake focal plane mechanisms from the New Madrid seismic zone are available to update regional stress data and two earthquake focal plane mechanisms originally published in the 1970's have recently been revised. Utilizing these data, we demonstrate that the earthquakes occur on nodal planes which are optimally-oriented for shear failure in the current stress field assuming hydrostatic pore pressure in the brittle crust and coefficients of friction (μ) of about 0.6. The average SHmax orientation inferred from P-axes of the 12 focal mechanisms is N84E +/- 21°, which is consistent with the overall trend of SHmax in the region. In a manner similar to the study by M.L. Zoback (JGR, 1992), which utilized a slightly smaller (and in two cases, less reliable) set of focal mechanisms in this area, we use the orientation of the focal mechanism nodal planes combined with independent stress data to investigate the compatibility of slip on both nodal planes in the current stress field. First, the relative magnitudes of the three principal stresses are calculated from the nodal plane and stress orientations. Next, we utilize Mohr-Coulomb failure criterion to calculate the theoretically-optimal orientation of a fault plane for different coefficients of friction. Lastly, we calculate the difference in orientation between the theoretically-optimal planes and the focal mechanism nodal planes and identify the nodal plane with the smaller difference as the preferred nodal plane. For μ = 0
Zhou, Tao; Gao, Yi; Zhu, Jian -Xin
2015-03-07
Recenmore » tly it was revealed that the whole Fermi surface is fully gapped for several families of underdoped cuprates. The existence of the finite energy gap along the d-wave nodal lines (nodal gap) contrasts the common understanding of the d-wave pairing symmetry, which challenges the present theories for the high-Tcsuperconductors. Here we propose that the incommensurate diagonal spin-density-wave order can account for the above experimental observation. The Fermi surface and the local density of states are also studied. Our results are in good agreement with many important experiments in high-Tcsuperconductors.« less
NASA Astrophysics Data System (ADS)
Wintermeyer, Niklas; Winters, Andrew R.; Gassner, Gregor J.; Kopriva, David A.
2017-07-01
We design an arbitrary high-order accurate nodal discontinuous Galerkin spectral element approximation for the non-linear two dimensional shallow water equations with non-constant, possibly discontinuous, bathymetry on unstructured, possibly curved, quadrilateral meshes. The scheme is derived from an equivalent flux differencing formulation of the split form of the equations. We prove that this discretization exactly preserves the local mass and momentum. Furthermore, combined with a special numerical interface flux function, the method exactly preserves the mathematical entropy, which is the total energy for the shallow water equations. By adding a specific form of interface dissipation to the baseline entropy conserving scheme we create a provably entropy stable scheme. That is, the numerical scheme discretely satisfies the second law of thermodynamics. Finally, with a particular discretization of the bathymetry source term we prove that the numerical approximation is well-balanced. We provide numerical examples that verify the theoretical findings and furthermore provide an application of the scheme for a partial break of a curved dam test problem.
Saltstone Clean Cap Formulation
Langton, C
2005-04-22
The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 weight percent cement/slag/fly ash) and domestic water that resembled as closely as possible the properties of the Saltstone slurry. In addition, options were investigated that may offer advantages such as less bleed water and less heat generation. The options with less bleed water required addition of dispersants. The options with lower heat contained more fly ash and less slag. A mix containing 10/45/45 weight percent cement/slag/fly ash with a water to premix ratio of 0.60 is recommended for the Clean Cap. Although this mix may generate more than 3 volume percent standing water (bleed water), it has rheological, mixing and flow properties that are similar to previously processed Saltstone. The recommended
Quantum mechanics with coordinate dependent noncommutativity
NASA Astrophysics Data System (ADS)
Kupriyanov, V. G.
2013-11-01
Noncommutative quantum mechanics can be considered as a first step in the construction of quantum field theory on noncommutative spaces of generic form, when the commutator between coordinates is a function of these coordinates. In this paper we discuss the mathematical framework of such a theory. The noncommutativity is treated as an external antisymmetric field satisfying the Jacobi identity. First, we propose a symplectic realization of a given Poisson manifold and construct the Darboux coordinates on the obtained symplectic manifold. Then we define the star product on a Poisson manifold and obtain the expression for the trace functional. The above ingredients are used to formulate a nonrelativistic quantum mechanics on noncommutative spaces of general form. All considered constructions are obtained as a formal series in the parameter of noncommutativity. In particular, the complete algebra of commutation relations between coordinates and conjugated momenta is a deformation of the standard Heisenberg algebra. As examples we consider a free particle and an isotropic harmonic oscillator on the rotational invariant noncommutative space.
Quantum mechanics with coordinate dependent noncommutativity
Kupriyanov, V. G.
2013-11-15
Noncommutative quantum mechanics can be considered as a first step in the construction of quantum field theory on noncommutative spaces of generic form, when the commutator between coordinates is a function of these coordinates. In this paper we discuss the mathematical framework of such a theory. The noncommutativity is treated as an external antisymmetric field satisfying the Jacobi identity. First, we propose a symplectic realization of a given Poisson manifold and construct the Darboux coordinates on the obtained symplectic manifold. Then we define the star product on a Poisson manifold and obtain the expression for the trace functional. The above ingredients are used to formulate a nonrelativistic quantum mechanics on noncommutative spaces of general form. All considered constructions are obtained as a formal series in the parameter of noncommutativity. In particular, the complete algebra of commutation relations between coordinates and conjugated momenta is a deformation of the standard Heisenberg algebra. As examples we consider a free particle and an isotropic harmonic oscillator on the rotational invariant noncommutative space.
Existence of frozen-in coordinate systems
NASA Technical Reports Server (NTRS)
Chertkov, A. D.
1995-01-01
The 'frozen-in' coordinate systems were first introduced in the works on 'reconnection' and 'magnetic barrier' theories (see review by M.l.Pudovkin and V.S.Semenov, Space Sci. Rev. 41,1 1985). The idea was to utilize the mathematical apparatus developed for 'general relativity' theory to simplify obtaining solutions to the ideal MHD equations set. Magnetic field (B), plasma velocity (v), and their vector product were used as coordinate vectors. But there exist no stationary solutions of ideal MHD set that satisfies the required boundary conditions at infinity (A.D.Chertkov, Solar Wind Seven Conf.,Pergamon Press,1992,165) having non-zero vector product of v and B where v and B originate from the same sphere. The existence of a solution is the hidden mine of the mentioned theories. The solution is constructed in the coordinate system, which is unknown and indeterminate before obtaining this solution. A substitution of the final solution must be done directly into the initial MHD set in order to check the method. One can demonstrate that 'solutions' of Petschek's problem, obtained by 'frozen-in' coordinate systems, does not satisfy just the 'frozen-in' equation, i.e. induction equation. It stems from the fact that Petschek's 're-connection' model, treated as a boundary problem, is over determined. This problem was incorrectly formulated.
Operator Formulation of Classical Mechanics.
ERIC Educational Resources Information Center
Cohn, Jack
1980-01-01
Discusses the construction of an operator formulation of classical mechanics which is directly concerned with wave packets in configuration space and is more similar to that of convential quantum theory than other extant operator formulations of classical mechanics. (Author/HM)
Biopsychosocial Formulation: Recognizing Educational Shortcomings
ERIC Educational Resources Information Center
McClain, Tina; O'Sullivan, Patricia S.; Clardy, James A.
2004-01-01
Objective: Since Engel introduced the biopsychosocial model, it has been extensively examined. The authors expect psychiatrists to formulate cases using the biopsychosocial model. However, resident psychiatrists' ability to generate formulations using this model has received little attention. Methods: The authors evaluated resident biopsychosocial…
Operator Formulation of Classical Mechanics.
ERIC Educational Resources Information Center
Cohn, Jack
1980-01-01
Discusses the construction of an operator formulation of classical mechanics which is directly concerned with wave packets in configuration space and is more similar to that of convential quantum theory than other extant operator formulations of classical mechanics. (Author/HM)
Biopsychosocial Formulation: Recognizing Educational Shortcomings
ERIC Educational Resources Information Center
McClain, Tina; O'Sullivan, Patricia S.; Clardy, James A.
2004-01-01
Objective: Since Engel introduced the biopsychosocial model, it has been extensively examined. The authors expect psychiatrists to formulate cases using the biopsychosocial model. However, resident psychiatrists' ability to generate formulations using this model has received little attention. Methods: The authors evaluated resident biopsychosocial…
Hilbert, Sebastian; Kosiuk, Jedrzej; John, Silke; Hindricks, Gerhard; Bollmann, Andreas
2016-01-01
A 74-year old was considered for atrioventricular (AV) nodal ablation in view of atrial fibrillation (AF) with poorly controlled ventricular rate despite being on amiodarone. Targeted AV nodal ablation was successfully performed after identifying the target site for ablation by reviewing an ultra high-density map of the His region produced by automatic electrogram annotation. PMID:25852249
Transport and optics at the node in a nodal loop semimetal
NASA Astrophysics Data System (ADS)
Mukherjee, S. P.; Carbotte, J. P.
2017-06-01
We use a Kubo formalism to calculate both AC conductivity and DC transport properties of a dirty nodal loop semimetal. The optical conductivity as a function of photon energy Ω exhibits an extended flat background σBG as in graphene provided the scattering rate Γ is small as compared to the radius of the nodal ring b (in energy units). Modifications to the constant background arise for Ω ≤Γ and the minimum DC conductivity σDC, which is approached as Ω2/Γ2 as Ω →0 , is found to be proportional to √{Γ/2+b2 }vF with vF the Fermi velocity. For b =0 we recover the known three-dimensional point node Dirac result σDC˜Γ/vF while for b >Γ , σDC becomes independent of Γ (universal) and the ratio σ/DCσBG=8/π2 where all reference to material parameters has dropped out. As b is reduced and becomes of the order Γ , the flat background is lost as the optical response evolves towards that of a three-dimensional point node Dirac semimetal which is linear in Ω for the clean limit. For finite Γ there are modifications from linearity in the photon region Ω ≤Γ . When the chemical potential μ (temperature T ) is nonzero the DC conductivity increases as μ2/Γ2 (T2/Γ2 ) for μ/Γ (T/Γ )≤1 . Such laws apply as well for thermal conductivity and thermopower with coefficients of the quadratic law only slightly modified from their value in the three-dimensional point node Dirac case. However in the μ =T =0 limit both have the same proportionality factor of √{Γ2+b2 } as does σDC. Consequently the Lorentz number is largely unmodified. For larger values of μ >Γ away from the nodal region the conductivity shows a Drude-like contribution about Ω ≊0 which is followed by a dip in the Pauli blocked region Ω ≤2 μ after which it increases to merge with the flat background (two-dimensional graphene like) for μ b .