Science.gov

Sample records for advanced nodal code

  1. Experience with advanced nodal codes at YAEC

    SciTech Connect

    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.

  2. Development of depletion perturbation theory for a reactor nodal code

    SciTech Connect

    Bowman, S.M.

    1981-09-01

    A generalized depletion perturbation (DPT) theory formulation for light water reactor (LWR) depletion problems is developed and implemented into the three-dimensional LWR nodal code SIMULATE. This development applies the principles of the original derivation by M.L. Williams to the nodal equations solved by SIMULATE. The present formulation is first described in detail, and the nodal coupling methodology in SIMULATE is used to determine partial derivatives of the coupling coefficients. The modifications to the original code and the new DPT options available to the user are discussed. Finally, the accuracy and the applicability of the new DPT capability to LWR design analysis are examined for several LWR depletion test cases. The cases range from simple static cases to a realistic PWR model for an entire fuel cycle. Responses of interest included K/sub eff/, nodal peaking, and peak nodal exposure. The nonlinear behavior of responses with respect to perturbations of the various types of cross sections was also investigated. The time-dependence of the sensitivity coefficients for different responses was examined and compared. Comparison of DPT results for these examples to direct calculations reveals the limited applicability of depletion perturbation theory to LWR design calculations at the present. The reasons for these restrictions are discussed, and several methods which might improve the computational accuracy of DPT are proposed for future research.

  3. A transient, Hex-Z nodal code corrected by discontinuity factors. Volume 1: The transient nodal code; Final report

    SciTech Connect

    Shatilla, Y.A.M.; Henry, A.F.

    1993-12-31

    This document constitutes Volume 1 of the Final Report of a three-year study supported by the special Research Grant Program for Nuclear Energy Research set up by the US Department of Energy. The original motivation for the work was to provide a fast and accurate computer program for the analysis of transients in heavy water or graphite-moderated reactors being considered as candidates for the New Production Reactor. Thus, part of the funding was by way of pass-through money from the Savannah River Laboratory. With this intent in mind, a three-dimensional (Hex-Z), general-energy-group transient, nodal code was created, programmed, and tested. In order to improve accuracy, correction terms, called {open_quotes}discontinuity factors,{close_quotes} were incorporated into the nodal equations. Ideal values of these factors force the nodal equations to provide node-integrated reaction rates and leakage rates across nodal surfaces that match exactly those edited from a more exact reference calculation. Since the exact reference solution is needed to compute the ideal discontinuity factors, the fact that they result in exact nodal equations would be of little practical interest were it not that approximate discontinuity factors, found at a greatly reduced cost, often yield very accurate results. For example, for light-water reactors, discontinuity factors found from two-dimensional, fine-mesh, multigroup transport solutions for two-dimensional cuts of a fuel assembly provide very accurate predictions of three-dimensional, full-core power distributions. The present document (volume 1) deals primarily with the specification, programming and testing of the three-dimensional, Hex-Z computer program. The program solves both the static (eigenvalue) and transient, general-energy-group, nodal equations corrected by user-supplied discontinuity factors.

  4. Three-Dimensional, Nodal, Neutron Diffusion Criticality Code System in Hex-Z Geometry.

    1992-07-27

    Version: 00 SIXTUS-3 is a 3D extention of SIXTUS-2 and is based on a response matrix nodal model. The code offers a fast and accurate analysis of critical systems in the regular hex-z geometry with the multigroup cross section representation including arbitrary upscattering.

  5. High-Speed Three-Dimensional Nodal Diffusion Code System.

    2001-03-21

    Version 00 MOSRA-Light is a three-dimensional diffusion calculation code for X-Y-Z geometry. It can be used in: validation of discontinuity factor for adjoint problem; benchmark on discontinuity factor (forward & adjoint cal.); DVP BWR Benchmark (2D,2G calculation); and void reactivity effect benchmark; etc. A utility code called More-MOSRA provides many useful functions with the file produced by MOSRA-Light.

  6. Theoretical basis of the linear nodal and linear characteristic methods in the TORT computer code

    SciTech Connect

    Childs, R.L.; Rhoades, W.A.

    1993-01-01

    Novel numerical procedures for solving the Boltzmann equation have been added to the Three Dimensional Oak Ridge Discrete Ordinates Transport Code (TORT). These procedures produce much more accuracy in theflux solutions for a given mesh size, or allow a smaller mesh to be used in order to reduce costs. The first method is a special adaptation of the linear nodal method proposed by Walters and O'Dell. The basic method has been extensively adapted in order to avoid numerical distortions that may occur in shielding problems. The second method is a characteristic procedure with linear expansion of sources and boundary flows. These methods are in widespread use in the TORT code.

  7. Theoretical basis of the linear nodal and linear characteristic methods in the TORT computer code

    SciTech Connect

    Childs, R.L.; Rhoades, W.A.

    1993-01-01

    Novel numerical procedures for solving the Boltzmann equation have been added to the Three Dimensional Oak Ridge Discrete Ordinates Transport Code (TORT). These procedures produce much more accuracy in theflux solutions for a given mesh size, or allow a smaller mesh to be used in order to reduce costs. The first method is a special adaptation of the linear nodal method proposed by Walters and O`Dell. The basic method has been extensively adapted in order to avoid numerical distortions that may occur in shielding problems. The second method is a characteristic procedure with linear expansion of sources and boundary flows. These methods are in widespread use in the TORT code.

  8. Recognizing nodal marginal zone lymphoma: recent advances and pitfalls. A systematic review

    PubMed Central

    van den Brand, Michiel; van Krieken, J. Han J.M.

    2013-01-01

    The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity. PMID:23813646

  9. Prevalence and distribution pattern of nodal metastases in advanced ovarian cancer

    PubMed Central

    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

  10. Advanced computational methods for nodal diffusion, Monte Carlo, and S(sub N) problems

    NASA Astrophysics Data System (ADS)

    Martin, W. R.

    1993-01-01

    This document describes progress on five efforts for improving effectiveness of computational methods for particle diffusion and transport problems in nuclear engineering: (1) Multigrid methods for obtaining rapidly converging solutions of nodal diffusion problems. An alternative line relaxation scheme is being implemented into a nodal diffusion code. Simplified P2 has been implemented into this code. (2) Local Exponential Transform method for variance reduction in Monte Carlo neutron transport calculations. This work yielded predictions for both 1-D and 2-D x-y geometry better than conventional Monte Carlo with splitting and Russian Roulette. (3) Asymptotic Diffusion Synthetic Acceleration methods for obtaining accurate, rapidly converging solutions of multidimensional SN problems. New transport differencing schemes have been obtained that allow solution by the conjugate gradient method, and the convergence of this approach is rapid. (4) Quasidiffusion (QD) methods for obtaining accurate, rapidly converging solutions of multidimensional SN Problems on irregular spatial grids. A symmetrized QD method has been developed in a form that results in a system of two self-adjoint equations that are readily discretized and efficiently solved. (5) Response history method for speeding up the Monte Carlo calculation of electron transport problems. This method was implemented into the MCNP Monte Carlo code. In addition, we have developed and implemented a parallel time-dependent Monte Carlo code on two massively parallel processors.

  11. Advanced computational methods for nodal diffusion, Monte Carlo, and S[sub N] problems

    SciTech Connect

    Martin, W.R.

    1993-01-01

    This document describes progress on five efforts for improving effectiveness of computational methods for particle diffusion and transport problems in nuclear engineering: (1) Multigrid methods for obtaining rapidly converging solutions of nodal diffusion problems. A alternative line relaxation scheme is being implemented into a nodal diffusion code. Simplified P2 has been implemented into this code. (2) Local Exponential Transform method for variance reduction in Monte Carlo neutron transport calculations. This work yielded predictions for both 1-D and 2-D x-y geometry better than conventional Monte Carlo with splitting and Russian Roulette. (3) Asymptotic Diffusion Synthetic Acceleration methods for obtaining accurate, rapidly converging solutions of multidimensional SN problems. New transport differencing schemes have been obtained that allow solution by the conjugate gradient method, and the convergence of this approach is rapid. (4) Quasidiffusion (QD) methods for obtaining accurate, rapidly converging solutions of multidimensional SN Problems on irregular spatial grids. A symmetrized QD method has been developed in a form that results in a system of two self-adjoint equations that are readily discretized and efficiently solved. (5) Response history method for speeding up the Monte Carlo calculation of electron transport problems. This method was implemented into the MCNP Monte Carlo code. In addition, we have developed and implemented a parallel time-dependent Monte Carlo code on two massively parallel processors.

  12. Clinically Apparent Internal Mammary Nodal Metastasis in Patients With Advanced Breast Cancer: Incidence and Local Control

    SciTech Connect

    Zhang Yujing; Oh, Julia L.; Whitman, Gary J.

    2010-07-15

    Purpose: To investigate the incidence and local control of internal mammary lymph node metastases (IMN+) in patients with clinical N2 or N3 locally advanced breast cancer. Methods and Materials: We retrospectively reviewed the records of 809 breast cancer patients diagnosed with advanced nodal disease (clinical N2-3) who received radiation treatment at our institution from January 2000 December 2006. Patients were considered IMN+ on the basis of imaging studies. Results: We identified 112 of 809 patients who presented with IMN+ disease (13.8%) detected on ultrasound, computed tomography (CT), positron emission tomography/CT (PET/CT), and/or magnetic resonance imaging (MRI) studies. All 112 patients with IMN+ disease received anthracycline and taxane-based chemotherapy. Neoadjuvant chemotherapy (NCT) resulted in a complete response (CR) on imaging studies of IMN disease in 72.1% of patients. Excluding 16 patients with progressive disease, 96 patients received adjuvant radiation to the breast or the chest wall and the regional lymphatics including the IMN chain with a median dose of 60 Gy if the internal mammary lymph nodes normalized after chemotherapy and 66 Gy if they did not. The median follow-up of surviving patients was 41 months (8-118 months). For the 96 patients able to complete curative therapy, the actuarial 5-year IMN control rate, locoregional control, overall survival, and disease-free survival were 89%, 80%, 76%, and 56%. Conclusion: Over ten percent of patients with advanced nodal disease will have IMN metastases on imaging studies. Multimodality therapy including IMN irradiation achieves excellent rates of control in the IMN region and a DFS of more than 50% after curative treatment.

  13. Impact of Incidental Irradiation on Clinically Uninvolved Nodal Regions in Patients With Advanced Non-Small-Cell Lung Cancer Treated With Involved-Field Radiation Therapy: Does Incidental Irradiation Contribute to the Low Incidence of Elective Nodal Failure?

    SciTech Connect

    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.

  14. Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code

    SciTech Connect

    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.

  15. A Nodal Kinetics and Thermohydraulics Analysis (NOKTA) Code for Analyzing Rod-Ejection Accidents and Other Transients in Nuclear Power Reactor Cores

    SciTech Connect

    Kaya, Sadi; Yavuz, Hasbi

    2000-01-15

    For analyzing nuclear power reactor core transients, a three-dimensional nodal kinetics and thermohydraulics code, NOKTA, was developed. Nodal kinetics calculation is based on a one-group neutron diffusion approach. Thermal-hydraulics analysis is handled as in the COBRA-IV-I code. The NOKTA code was designed for analyzing especially large reactivity accidents, such as sudden rod ejection. It can also analyze intermediate transients, such as sharp power changes that may initiate xenon oscillations, and slow transients, such as boric acid density changes in the flow. The code dimensions are set at 125 subchannels and 30 axial levels. Calculation starts with a saturated xenon density, one-group neutronics parameters, and a flux profile, which is required as an input. Initially, k{sub eff} of each computation cell is set to unity.

  16. Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

    SciTech Connect

    Shih, Helen A. . E-mail: hshih@partners.org; Harisinghani, Mukesh; Zietman, Anthony L.; Wolfgang, John A.; Saksena, Mansi; Weissleder, Ralph

    2005-11-15

    Purpose: Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard 'four-field box.' We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer. Methods and Materials: Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to a common template based on its relation to skeletal or vascular anatomy. Results: Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort. Conclusions: Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities.

  17. Advanced Nodal P3/SP3 Axial Transport Solvers for the MPACT 2D/1D Scheme

    SciTech Connect

    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 P3/SP3 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 P3/SP3 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-SP3 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-SP3 solver is still under development, it is intended to resolve the issues with HY-NEM-SP3 but it will incur some additional computational burden by necessitating an additional 1D-CMFD-P3 solver to generate the second moment cell-averaged scalar flux.

  18. Advanced Code for Photocathode Design

    SciTech Connect

    Ives, Robert Lawrence; Jensen, Kevin; Montgomery, Eric; Bui, Thuc

    2015-12-15

    The Phase I activity demonstrated that PhotoQE could be upgraded and modified to allow input using a graphical user interface. Specific calls to platform-dependent (e.g. IMSL) function calls were removed, and Fortran77 components were rewritten for Fortran95 compliance. The subroutines, specifically the common block structures and shared data parameters, were reworked to allow the GUI to update material parameter data, and the system was targeted for desktop personal computer operation. The new structures overcomes the previous rigid and unmodifiable library structures by implementing new, materials library data sets and repositioning the library values to external files. Material data may originate from published literature or experimental measurements. Further optimization and restructuring would allow custom and specific emission models for beam codes that rely on parameterized photoemission algorithms. These would be based on simplified and parametric representations updated and extended from previous versions (e.g., Modified Fowler-Dubridge, Modified Three-Step, etc.).

  19. Parametric Analysis of a Turbine Trip Event in a BWR Using a 3D Nodal Code

    SciTech Connect

    Gorzel, A.

    2006-07-01

    Two essential thermal hydraulics safety criteria concerning the reactor core are that even during operational transients there is no fuel melting and not-permissible cladding temperatures are avoided. A common concept for boiling water reactors is to establish a minimum critical power ratio (MCPR) for steady state operation. For this MCPR it is shown that only a very small number of fuel rods suffers a short-term dryout during the transient. It is known from experience that the limiting transient for the determination of the MCPR is the turbine trip with blocked bypass system. This fast transient was simulated for a German BWR by use of the three-dimensional reactor analysis transient code SIMULATE-3K. The transient behaviour of the hot channels was used as input for the dryout calculation with the transient thermal hydraulics code FRANCESCA. By this way the maximum reduction of the CPR during the transient could be calculated. The fast increase in reactor power due to the pressure increase and to an increased core inlet flow is limited mainly by the Doppler effect, but automatically triggered operational measures also can contribute to the mitigation of the turbine trip. One very important method is the short-term fast reduction of the recirculation pump speed which is initiated e. g. by a pressure increase in front of the turbine. The large impacts of the starting time and of the rate of the pump speed reduction on the power progression and hence on the deterioration of CPR is presented. Another important procedure to limit the effects of the transient is the fast shutdown of the reactor that is caused when the reactor power reaches the limit value. It is shown that the SCRAM is not fast enough to reduce the first power maximum, but is able to prevent the appearance of a second - much smaller - maximum that would occur around one second after the first one in the absence of a SCRAM. (author)

  20. Status of the Development of an Embedded Transport Treatment of Control Rods and of Radial Flux Expansion in Cylindrical Nodal Diffusion Codes

    SciTech Connect

    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).

  1. Advanced Modulation and Coding Technology Conference

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The objectives, approach, and status of all current LeRC-sponsored industry contracts and university grants are presented. The following topics are covered: (1) the LeRC Space Communications Program, and Advanced Modulation and Coding Projects; (2) the status of four contracts for development of proof-of-concept modems; (3) modulation and coding work done under three university grants, two small business innovation research contracts, and two demonstration model hardware development contracts; and (4) technology needs and opportunities for future missions.

  2. Improvement of advanced nodal method used in 3D core design system

    SciTech Connect

    Rauck, S.; Dall'Osso, A.

    2006-07-01

    This paper deals with AREVA NP progress in the modelling of neutronic phenomena, evaluated through 3D determinist core codes and using 2-group diffusion theory. Our report highlights the advantages of taking into account the assembly environment in the process used for the building of the 2-group collapsed neutronic parameters, such as cross sections or discontinuity factors. The interest of the present method, developed in order to account for the impact of the environment on the above mentioned parameters, resides (i) in the very definition of a global correlation between collapsed neutronic data calculated in an infinite medium and those calculated in a 3D-geometry, and (ii) in the use of a re-homogenization method. Using this approach, computations match better with actual measurements on control rod worth. They also present smaller differences on pin by pin power values compared to the ones computed with another code considered as a reference since it relies on multigroup transport theory. (authors)

  3. Advanced computational methods for nodal diffusion, Monte Carlo, and S{sub N} problems. Progress report, January 1, 1992--March 31, 1993

    SciTech Connect

    Martin, W.R.

    1993-01-01

    This document describes progress on five efforts for improving effectiveness of computational methods for particle diffusion and transport problems in nuclear engineering: (1) Multigrid methods for obtaining rapidly converging solutions of nodal diffusion problems. A alternative line relaxation scheme is being implemented into a nodal diffusion code. Simplified P2 has been implemented into this code. (2) Local Exponential Transform method for variance reduction in Monte Carlo neutron transport calculations. This work yielded predictions for both 1-D and 2-D x-y geometry better than conventional Monte Carlo with splitting and Russian Roulette. (3) Asymptotic Diffusion Synthetic Acceleration methods for obtaining accurate, rapidly converging solutions of multidimensional SN problems. New transport differencing schemes have been obtained that allow solution by the conjugate gradient method, and the convergence of this approach is rapid. (4) Quasidiffusion (QD) methods for obtaining accurate, rapidly converging solutions of multidimensional SN Problems on irregular spatial grids. A symmetrized QD method has been developed in a form that results in a system of two self-adjoint equations that are readily discretized and efficiently solved. (5) Response history method for speeding up the Monte Carlo calculation of electron transport problems. This method was implemented into the MCNP Monte Carlo code. In addition, we have developed and implemented a parallel time-dependent Monte Carlo code on two massively parallel processors.

  4. Advanced coding and modulation schemes for TDRSS

    NASA Technical Reports Server (NTRS)

    Harrell, Linda; Kaplan, Ted; Berman, Ted; Chang, Susan

    1993-01-01

    This paper describes the performance of the Ungerboeck and pragmatic 8-Phase Shift Key (PSK) Trellis Code Modulation (TCM) coding techniques with and without a (255,223) Reed-Solomon outer code as they are used for Tracking Data and Relay Satellite System (TDRSS) S-Band and Ku-Band return services. The performance of these codes at high data rates is compared to uncoded Quadrature PSK (QPSK) and rate 1/2 convolutionally coded QPSK in the presence of Radio Frequency Interference (RFI), self-interference, and hardware distortions. This paper shows that the outer Reed-Solomon code is necessary to achieve a 10(exp -5) Bit Error Rate (BER) with an acceptable level of degradation in the presence of RFI. This paper also shows that the TCM codes with or without the Reed-Solomon outer code do not perform well in the presence of self-interference. In fact, the uncoded QPSK signal performs better than the TCM coded signal in the self-interference situation considered in this analysis. Finally, this paper shows that the E(sub b)/N(sub 0) degradation due to TDRSS hardware distortions is approximately 1.3 dB with a TCM coded signal or a rate 1/2 convolutionally coded QPSK signal and is 3.2 dB with an uncoded QPSK signal.

  5. Advanced Imaging Optics Utilizing Wavefront Coding.

    SciTech Connect

    Scrymgeour, David; Boye, Robert; Adelsberger, Kathleen

    2015-06-01

    Image processing offers a potential to simplify an optical system by shifting some of the imaging burden from lenses to the more cost effective electronics. Wavefront coding using a cubic phase plate combined with image processing can extend the system's depth of focus, reducing many of the focus-related aberrations as well as material related chromatic aberrations. However, the optimal design process and physical limitations of wavefront coding systems with respect to first-order optical parameters and noise are not well documented. We examined image quality of simulated and experimental wavefront coded images before and after reconstruction in the presence of noise. Challenges in the implementation of cubic phase in an optical system are discussed. In particular, we found that limitations must be placed on system noise, aperture, field of view and bandwidth to develop a robust wavefront coded system.

  6. Code System to Perform Neutronic and Thermal-Hydraulic Subchannel Analysis from Converged Coarse-Mesh Nodal Solutions.

    2000-06-14

    Version 00 NORMA-FP is an auxiliary program which can perform a neutronic and thermal-hydraulic subchannel analysis, starting from global core calculations carried out by both PSR-471/NORMA or PSR-492/QUARK codes. Detailed flux and power distributions inside homogenized nodes are computed by a two-stage bivariate interpolation method, upon separation of the axial variable for which an analytical solution is adopted. The actual heterogeneous structure of a node is accounted for by fuel rod power factors computed asmore » functions of burnup, burnup-weighted coolant density, and instantaneous coolant density.« less

  7. Progress in Advanced Spray Combustion Code Integration

    NASA Technical Reports Server (NTRS)

    Liang, Pak-Yan

    1993-01-01

    A multiyear project to assemble a robust, muitiphase spray combustion code is now underway and gradually building up to full speed. The overall effort involves several university and government research teams as well as Rocketdyne. The first part of this paper will give an overview of the respective roles of the different participants involved, the master strategy, the evolutionary milestones, and an assessment of the state-of-the-art of various key components. The second half of this paper will highlight the progress made to date in extending the baseline Navier-Stokes solver to handle multiphase, multispecies, chemically reactive sub- to supersonic flows. The major hurdles to overcome in order to achieve significant speed ups are delineated and the approaches to overcoming them will be discussed.

  8. Foundational development of an advanced nuclear reactor integrated safety code.

    SciTech Connect

    Clarno, Kevin; Lorber, Alfred Abraham; Pryor, Richard J.; Spotz, William F.; Schmidt, Rodney Cannon; Belcourt, Kenneth; Hooper, Russell Warren; Humphries, Larry LaRon

    2010-02-01

    This report describes the activities and results of a Sandia LDRD project whose objective was to develop and demonstrate foundational aspects of a next-generation nuclear reactor safety code that leverages advanced computational technology. The project scope was directed towards the systems-level modeling and simulation of an advanced, sodium cooled fast reactor, but the approach developed has a more general applicability. The major accomplishments of the LDRD are centered around the following two activities. (1) The development and testing of LIME, a Lightweight Integrating Multi-physics Environment for coupling codes that is designed to enable both 'legacy' and 'new' physics codes to be combined and strongly coupled using advanced nonlinear solution methods. (2) The development and initial demonstration of BRISC, a prototype next-generation nuclear reactor integrated safety code. BRISC leverages LIME to tightly couple the physics models in several different codes (written in a variety of languages) into one integrated package for simulating accident scenarios in a liquid sodium cooled 'burner' nuclear reactor. Other activities and accomplishments of the LDRD include (a) further development, application and demonstration of the 'non-linear elimination' strategy to enable physics codes that do not provide residuals to be incorporated into LIME, (b) significant extensions of the RIO CFD code capabilities, (c) complex 3D solid modeling and meshing of major fast reactor components and regions, and (d) an approach for multi-physics coupling across non-conformal mesh interfaces.

  9. 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

  10. Advances in space radiation shielding codes.

    PubMed

    Wilson, John W; Tripathi, Ram K; Qualls, Garry D; Cucinotta, Francis A; Prael, Richard E; Norbury, John W; Heinbockel, John H; Tweed, John; De Angelis, Giovanni

    2002-12-01

    Early space radiation shield code development relied on Monte Carlo methods and made important contributions to the space program. Monte Carlo methods have resorted to restricted one-dimensional problems leading to imperfect representation of appropriate boundary conditions. Even so, intensive computational requirements resulted and shield evaluation was made near the end of the design process. Resolving shielding issues usually had a negative impact on the design. Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary concept to the final design. For the last few decades, we have pursued deterministic solutions of the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard Finite Element Method (FEM) geometry common to engineering design methods. A single ray trace in such geometry requires 14 milliseconds and limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given.

  11. Recent advances in the Mercury Monte Carlo particle transport code

    SciTech Connect

    Brantley, P. S.; Dawson, S. A.; McKinley, M. S.; O'Brien, M. J.; Stevens, D. E.; Beck, B. R.; Jurgenson, E. D.; Ebbers, C. A.; Hall, J. M.

    2013-07-01

    We review recent physics and computational science advances in the Mercury Monte Carlo particle transport code under development at Lawrence Livermore National Laboratory. We describe recent efforts to enable a nuclear resonance fluorescence capability in the Mercury photon transport. We also describe recent work to implement a probability of extinction capability into Mercury. We review the results of current parallel scaling and threading efforts that enable the code to run on millions of MPI processes. (authors)

  12. Development of UMARC (University of Maryland Advanced Rotorcraft Code)

    NASA Technical Reports Server (NTRS)

    Bir, Gunjit; Chopra, Inderjit; Nguyen, Khanh

    1990-01-01

    The University of Maryland Advanced Rotorcraft Code (UMARC) is a user-friendly, FEM-based comprehensive helicopter rotor simulation code of high numerical robustness and computational efficiency. UMARC formulates the rotor-fuselage equations using Hamilton's principle, and are discretized using finite elements in space and time. The FEM formulation allows the code to analyze a wide variety of rotor designs. Dynamic inflow modeling is used for unsteady wake inflow computations. Predicted stability, response, and blade-load data are validated with experimental data for several configurations, including representative articulated, hingeless, and bearingless rotors.

  13. Recent advances in neutral particle transport methods and codes

    NASA Astrophysics Data System (ADS)

    Azmy, Yousry Y.

    1997-02-01

    An overview of Oak Ridge National Laboratory's (ORNL) 3D neural particle transport code, TORT, is presented. Special features of the code that make it invaluable for large applications are summarized for the prospective user. Advanced capabilities currently under development and installation in the production release of TORT are discussed in some detail. These include: multitasking on Cray platforms running the UNICOS operating system; adjacent-cell preconditioning acceleration scheme; and graphics codes for displaying computed quantities such as the flux. Further developments for TORT and its companion codes to enhance its present capabilities, as well as expand its range of applications will be discussed. Speculation on the next generation of neutral particle transport codes at ORNL, especially regarding unstructured grids and high order spatial approximations, will also be mentioned.

  14. Recent advances in neutral particle transport methods and codes

    SciTech Connect

    Azmy, Y.Y.

    1996-06-01

    An overview of ORNL`s three-dimensional neutral particle transport code, TORT, is presented. Special features of the code that make it invaluable for large applications are summarized for the prospective user. Advanced capabilities currently under development and installation in the production release of TORT are discussed; they include: multitasking on Cray platforms running the UNICOS operating system; Adjacent cell Preconditioning acceleration scheme; and graphics codes for displaying computed quantities such as the flux. Further developments for TORT and its companion codes to enhance its present capabilities, as well as expand its range of applications are disucssed. Speculation on the next generation of neutron particle transport codes at ORNL, especially regarding unstructured grids and high order spatial approximations, are also mentioned.

  15. KEK NODAL system

    SciTech Connect

    Kurokawa, S.; Abe, K.; Akiyama, A.; Katoh, T.; Kikutani, E.; Koiso, H.; Kurihara, N.; Oide, K.; Shinomoto, M.

    1985-10-01

    The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fiber token ring network of twenty-four minicomputers (Hitachi HIDIC 80's) to control the TRISTAN accelerator complex, now being constructed at KEK. KEK NODAL retains main features of the original NODAL: the interpreting scheme, the multi-computer programming facility, and the data-module concept. In addition, it has the following characteristics: fast execution due to the compiler-interpreter method, a multicomputer file system, a full-screen editing facility, and a dynamic linkage scheme of data modules and NODAL functions. The structure of the KEK NODAL system under PMS, a real-time multitasking operating system of HIDIC 80, is described; the NODAL file system is also explained.

  16. Advances in Parallel Electromagnetic Codes for Accelerator Science and Development

    SciTech Connect

    Ko, Kwok; Candel, Arno; Ge, Lixin; Kabel, Andreas; Lee, Rich; Li, Zenghai; Ng, Cho; Rawat, Vineet; Schussman, Greg; Xiao, Liling; /SLAC

    2011-02-07

    Over a decade of concerted effort in code development for accelerator applications has resulted in a new set of electromagnetic codes which are based on higher-order finite elements for superior geometry fidelity and better solution accuracy. SLAC's ACE3P code suite is designed to harness the power of massively parallel computers to tackle large complex problems with the increased memory and solve them at greater speed. The US DOE supports the computational science R&D under the SciDAC project to improve the scalability of ACE3P, and provides the high performance computing resources needed for the applications. This paper summarizes the advances in the ACE3P set of codes, explains the capabilities of the modules, and presents results from selected applications covering a range of problems in accelerator science and development important to the Office of Science.

  17. Improved orthogonal frequency division multiplexing communications through advanced coding

    NASA Astrophysics Data System (ADS)

    Westra, Jeffrey; Patti, John

    2005-08-01

    Orthogonal Frequency Division Multiplexing (OFDM) is a communications technique that transmits a signal over multiple, evenly spaced, discrete frequency bands. OFDM offers some advantages over traditional, single-carrier modulation techniques, such as increased immunity to inter-symbol interference. For this reason OFDM is an attractive candidate for sensor network application; it has already been included in several standards, including Digital Audio Broadcast (DAB); digital television standards in Europe, Japan and Australia; asymmetric digital subscriber line (ASDL); and wireless local area networks (WLAN), specifically IEEE 802.11a. Many of these applications currently make use of a standard convolutional code with Viterbi decoding to perform forward error correction (FEC). Replacing such convolutional codes with advanced coding techniques using iterative decoding, such as Turbo codes, can substantially improve the performance of the OFDM communications link. This paper demonstrates such improvements using the 802.11a wireless LAN standard.

  18. Risk of Subclinical Micrometastatic Disease in the Supraclavicular Nodal Bed According to the Anatomic Distribution in Patients With Advanced Breast Cancer

    SciTech Connect

    Reed, Valerie K.; Cavalcanti, Jose L.; Strom, Eric A.; Perkins, George H.; Oh, Julia L.; Tereffe, Welela; Yu, T.-K.; Yeung, Henry; Whitman, Gary J.; Bedrosian, Isabelle; Macapinlac, Homer A.; Buchholz, Thomas A.; Woodward, Wendy A.

    2008-06-01

    Purpose: To determine the anatomic distribution of gross supraclavicular nodes within the supraclavicular fossa using 2-deoxy-2-[F-18] fluoro-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT) scans, and to evaluate likely coverage of specific regions of the supraclavicular fossa using standard radiation fields. Methods and Materials: We identified 33 patients with advanced or metastatic breast cancer who had a PET/CT scan demonstrating hypermetabolic supraclavicular lymph nodes in 2005. The locations of the involved lymph nodes were mapped onto a single CT set of images of the supraclavicular fossa. These lymph nodes were also mapped onto the treatment-planning CT dataset of 4 patients treated in our institution (2 patients with biopsy-proven supraclavicular nodes and 2 patients with clinically negative supraclavicular nodes). Results: We were able to determine the distribution of 52 supraclavicular lymph nodes in 32 patients. Of 32 patients, 28 (87%) had a history of metastatic disease, and 2 patients had isolated nodal recurrences. Five patients had supraclavicular nodes posterior to the vertebral body transverse process, and several lymph nodes were in close proximity to the medial field border, raising the possibility of geographic miss in these areas. Conclusions: In patients with locally advanced disease, increased coverage of the supraclavicular fossa medially and posteriorly may be warranted.

  19. ADVANCED ELECTRIC AND MAGNETIC MATERIAL MODELS FOR FDTD ELECTROMAGNETIC CODES

    SciTech Connect

    Poole, B R; Nelson, S D; Langdon, S

    2005-05-05

    The modeling of dielectric and magnetic materials in the time domain is required for pulse power applications, pulsed induction accelerators, and advanced transmission lines. For example, most induction accelerator modules require the use of magnetic materials to provide adequate Volt-sec during the acceleration pulse. These models require hysteresis and saturation to simulate the saturation wavefront in a multipulse environment. In high voltage transmission line applications such as shock or soliton lines the dielectric is operating in a highly nonlinear regime, which require nonlinear models. Simple 1-D models are developed for fast parameterization of transmission line structures. In the case of nonlinear dielectrics, a simple analytic model describing the permittivity in terms of electric field is used in a 3-D finite difference time domain code (FDTD). In the case of magnetic materials, both rate independent and rate dependent Hodgdon magnetic material models have been implemented into 3-D FDTD codes and 1-D codes.

  20. User's manual: Subsonic/supersonic advanced panel pilot code

    NASA Technical Reports Server (NTRS)

    Moran, J.; Tinoco, E. N.; Johnson, F. T.

    1978-01-01

    Sufficient instructions for running the subsonic/supersonic advanced panel pilot code were developed. This software was developed as a vehicle for numerical experimentation and it should not be construed to represent a finished production program. The pilot code is based on a higher order panel method using linearly varying source and quadratically varying doublet distributions for computing both linearized supersonic and subsonic flow over arbitrary wings and bodies. This user's manual contains complete input and output descriptions. A brief description of the method is given as well as practical instructions for proper configurations modeling. Computed results are also included to demonstrate some of the capabilities of the pilot code. The computer program is written in FORTRAN IV for the SCOPE 3.4.4 operations system of the Ames CDC 7600 computer. The program uses overlay structure and thirteen disk files, and it requires approximately 132000 (Octal) central memory words.

  1. Extension of the linear nodal method to large concrete building calculations

    SciTech Connect

    Childs, R.L.; Rhoades, W.A.

    1985-01-01

    The implementation of the linear nodal method in the TORT code is described, and the results of a mesh refinement study to test the effectiveness of the linear nodal and weighted diamond difference methods available in TORT are presented.

  2. Code qualification of structural materials for AFCI advanced recycling reactors.

    SciTech Connect

    Natesan, K.; Li, M.; Majumdar, S.; Nanstad, R.K.; Sham, T.-L.

    2012-05-31

    This report summarizes the further findings from the assessments of current status and future needs in code qualification and licensing of reference structural materials and new advanced alloys for advanced recycling reactors (ARRs) in support of Advanced Fuel Cycle Initiative (AFCI). The work is a combined effort between Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL) with ANL as the technical lead, as part of Advanced Structural Materials Program for AFCI Reactor Campaign. The report is the second deliverable in FY08 (M505011401) under the work package 'Advanced Materials Code Qualification'. The overall objective of the Advanced Materials Code Qualification project is to evaluate key requirements for the ASME Code qualification and the Nuclear Regulatory Commission (NRC) approval of structural materials in support of the design and licensing of the ARR. Advanced materials are a critical element in the development of sodium reactor technologies. Enhanced materials performance not only improves safety margins and provides design flexibility, but also is essential for the economics of future advanced sodium reactors. Code qualification and licensing of advanced materials are prominent needs for developing and implementing advanced sodium reactor technologies. Nuclear structural component design in the U.S. must comply with the ASME Boiler and Pressure Vessel Code Section III (Rules for Construction of Nuclear Facility Components) and the NRC grants the operational license. As the ARR will operate at higher temperatures than the current light water reactors (LWRs), the design of elevated-temperature components must comply with ASME Subsection NH (Class 1 Components in Elevated Temperature Service). However, the NRC has not approved the use of Subsection NH for reactor components, and this puts additional burdens on materials qualification of the ARR. In the past licensing review for the Clinch River Breeder Reactor Project (CRBRP) and the

  3. Nodal equivalence theory for hexagonal geometry, thermal reactor analysis

    SciTech Connect

    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.

  4. Beam Optics Analysis - An Advanced 3D Trajectory Code

    SciTech Connect

    Ives, R. Lawrence; Bui, Thuc; Vogler, William; Neilson, Jeff; Read, Mike; Shephard, Mark; Bauer, Andrew; Datta, Dibyendu; Beal, Mark

    2006-01-03

    Calabazas Creek Research, Inc. has completed initial development of an advanced, 3D program for modeling electron trajectories in electromagnetic fields. The code is being used to design complex guns and collectors. Beam Optics Analysis (BOA) is a fully relativistic, charged particle code using adaptive, finite element meshing. Geometrical input is imported from CAD programs generating ACIS-formatted files. Parametric data is inputted using an intuitive, graphical user interface (GUI), which also provides control of convergence, accuracy, and post processing. The program includes a magnetic field solver, and magnetic information can be imported from Maxwell 2D/3D and other programs. The program supports thermionic emission and injected beams. Secondary electron emission is also supported, including multiple generations. Work on field emission is in progress as well as implementation of computer optimization of both the geometry and operating parameters. The principle features of the program and its capabilities are presented.

  5. Beam Optics Analysis — An Advanced 3D Trajectory Code

    NASA Astrophysics Data System (ADS)

    Ives, R. Lawrence; Bui, Thuc; Vogler, William; Neilson, Jeff; Read, Mike; Shephard, Mark; Bauer, Andrew; Datta, Dibyendu; Beal, Mark

    2006-01-01

    Calabazas Creek Research, Inc. has completed initial development of an advanced, 3D program for modeling electron trajectories in electromagnetic fields. The code is being used to design complex guns and collectors. Beam Optics Analysis (BOA) is a fully relativistic, charged particle code using adaptive, finite element meshing. Geometrical input is imported from CAD programs generating ACIS-formatted files. Parametric data is inputted using an intuitive, graphical user interface (GUI), which also provides control of convergence, accuracy, and post processing. The program includes a magnetic field solver, and magnetic information can be imported from Maxwell 2D/3D and other programs. The program supports thermionic emission and injected beams. Secondary electron emission is also supported, including multiple generations. Work on field emission is in progress as well as implementation of computer optimization of both the geometry and operating parameters. The principle features of the program and its capabilities are presented.

  6. Modern transform design for advanced image/video coding applications

    NASA Astrophysics Data System (ADS)

    Tran, Trac D.; Topiwala, Pankaj N.

    2008-08-01

    This paper offers an overall review of recent advances in the design of modern transforms for image and video coding applications. Transforms have been an integral part of signal coding applications from the beginning, but emphasis had been on true floating-point transforms for most of that history. Recently, with the proliferation of low-power handheld multimedia devices, a new vision of integer-only transforms that provide high performance yet very low complexity has quickly gained ascendency. We explore two key design approaches to creating integer transforms, and focus on a systematic, universal method based on decomposition into lifting steps, and use of (dyadic) rational coefficients. This method provides a wealth of solutions, many of which are already in use in leading media codecs today, such as H.264, HD Photo/JPEG XR, and scalable audio. We give early indications in this paper, and more fully elsewhere.

  7. Small renal tumor with lymph nodal enlargement: A histopathological surprise

    PubMed Central

    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

  8. Automatic differentiation of advanced CFD codes for multidisciplinary design

    SciTech Connect

    Bischof, C.; Corliss, G.; Griewank, A.; Green, L.; Haigler, K.; Newman, P.

    1992-12-31

    Automated multidisciplinary design of aircraft and other flight vehicles requires the optimization of complex performance objectives with respect to a number of design parameters and constraints. The effect of these independent design variables on the system performance criteria can be quantified in terms of sensitivity derivatives which must be calculated and propagated by the individual discipline simulation codes. Typical advanced CFD analysis codes do not provide such derivatives as part of a flow solution; these derivatives are very expensive to obtain by divided (finite) differences from perturbed solutions. It is shown here that sensitivity derivatives can be obtained accurately and efficiently using the ADIFOR source translator for automatic differentiation. In particular, it is demonstrated that the 3-D, thin-layer Navier-Stokes, multigrid flow solver called TLNS3D is amenable to automatic differentiation in the forward mode even with its implicit iterative solution algorithm and complex turbulence modeling. It is significant that using computational differentiation, consistent discrete nongeometric sensitivity derivatives have been obtained from an aerodynamic 3-D CFD code in a relatively short time, e.g. O(man-week) not O(man-year).

  9. Automatic differentiation of advanced CFD codes for multidisciplinary design

    SciTech Connect

    Bischof, C.; Corliss, G.; Griewank, A. ); Green, L.; Haigler, K.; Newman, P. . Langley Research Center)

    1992-01-01

    Automated multidisciplinary design of aircraft and other flight vehicles requires the optimization of complex performance objectives with respect to a number of design parameters and constraints. The effect of these independent design variables on the system performance criteria can be quantified in terms of sensitivity derivatives which must be calculated and propagated by the individual discipline simulation codes. Typical advanced CFD analysis codes do not provide such derivatives as part of a flow solution; these derivatives are very expensive to obtain by divided (finite) differences from perturbed solutions. It is shown here that sensitivity derivatives can be obtained accurately and efficiently using the ADIFOR source translator for automatic differentiation. In particular, it is demonstrated that the 3-D, thin-layer Navier-Stokes, multigrid flow solver called TLNS3D is amenable to automatic differentiation in the forward mode even with its implicit iterative solution algorithm and complex turbulence modeling. It is significant that using computational differentiation, consistent discrete nongeometric sensitivity derivatives have been obtained from an aerodynamic 3-D CFD code in a relatively short time, e.g. O(man-week) not O(man-year).

  10. Advanced coding techniques for few mode transmission systems.

    PubMed

    Okonkwo, Chigo; van Uden, Roy; Chen, Haoshuo; de Waardt, Huug; Koonen, Ton

    2015-01-26

    We experimentally verify the advantage of employing advanced coding schemes such as space-time coding and 4 dimensional modulation formats to enhance the transmission performance of a 3-mode transmission system. The performance gain of space-time block codes for extending the optical signal-to-noise ratio tolerance in multiple-input multiple-output optical coherent spatial division multiplexing transmission systems with respect to single-mode transmission performance are evaluated. By exploiting the spatial diversity that few-mode-fibers offer, with respect to single mode fiber back-to-back performance, significant OSNR gains of 3.2, 4.1, 4.9, and 6.8 dB at the hard-decision forward error correcting limit are demonstrated for DP-QPSK 8, 16 and 32 QAM, respectively. Furthermore, by employing 4D constellations, 6 × 28Gbaud 128 set partitioned quadrature amplitude modulation is shown to outperform conventional 8 QAM transmission performance, whilst carrying an additional 0.5 bit/symbol.

  11. Human Cerberus Prevents Nodal-Receptor Binding, Inhibits Nodal Signaling, and Suppresses Nodal-Mediated Phenotypes

    PubMed Central

    Aykul, Senem; Ni, Wendi; Mutatu, Washington; Martinez-Hackert, Erik

    2015-01-01

    The Transforming Growth Factor-ß (TGFß) family ligand Nodal is an essential embryonic morphogen that is associated with progression of breast and other cancers. It has therefore been suggested that Nodal inhibitors could be used to treat breast cancers where Nodal plays a defined role. As secreted antagonists, such as Cerberus, tightly regulate Nodal signaling during embryonic development, we undertook to produce human Cerberus, characterize its biochemical activities, and determine its effect on human breast cancer cells. Using quantitative methods, we investigated the mechanism of Nodal signaling, we evaluated binding of human Cerberus to Nodal and other TGFß family ligands, and we characterized the mechanism of Nodal inhibition by Cerberus. Using cancer cell assays, we examined the ability of Cerberus to suppress aggressive breast cancer cell phenotypes. We found that human Cerberus binds Nodal with high affinity and specificity, blocks binding of Nodal to its signaling partners, and inhibits Nodal signaling. Moreover, we showed that Cerberus profoundly suppresses migration, invasion, and colony forming ability of Nodal expressing and Nodal supplemented breast cancer cells. Taken together, our studies provide mechanistic insights into Nodal signaling and Nodal inhibition with Cerberus and highlight the potential value of Cerberus as anti-Nodal therapeutic. PMID:25603319

  12. Advances in pleural disease management including updated procedural coding.

    PubMed

    Haas, Andrew R; Sterman, Daniel H

    2014-08-01

    Over 1.5 million pleural effusions occur in the United States every year as a consequence of a variety of inflammatory, infectious, and malignant conditions. Although rarely fatal in isolation, pleural effusions are often a marker of a serious underlying medical condition and contribute to significant patient morbidity, quality-of-life reduction, and mortality. Pleural effusion management centers on pleural fluid drainage to relieve symptoms and to investigate pleural fluid accumulation etiology. Many recent studies have demonstrated important advances in pleural disease management approaches for a variety of pleural fluid etiologies, including malignant pleural effusion, complicated parapneumonic effusion and empyema, and chest tube size. The last decade has seen greater implementation of real-time imaging assistance for pleural effusion management and increasing use of smaller bore percutaneous chest tubes. This article will briefly review recent pleural effusion management literature and update the latest changes in common procedural terminology billing codes as reflected in the changing landscape of imaging use and percutaneous approaches to pleural disease management.

  13. Nodal-chain metals

    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.

  14. Recent advances in the COMMIX and BODYFIT codes

    SciTech Connect

    Sha, W.T.; Chen, B.C.J.; Domanus, H.M.; Wood, P.M.

    1983-01-01

    Two general-purpose computer programs for thermal-hydraulic analysis have been developed. One is the COMMIX (COMponent MIXing code. The other one is the BODYFIT (BOunDary FITted Coordinate Transformation) code. Solution procedures based on both elliptical and parabolic systems of partial differential equations are provided in these two codes. The COMMIX code is designed to provide global analysis of thermal-hydraulic behavior of a component or multicomponent of engineering problems. The BODYFIT code is capable of treating irregular boundaries and gives more detailed local information on a subcomponent or component. These two codes are complementary to each other and represent the state-of-the-art of thermal-hydraulic analysis. Effort will continue to make further improvements and include additional capabilities in these codes.

  15. A semianalytic two-group nodal model for SIMULATE-3

    SciTech Connect

    Esser, P.D.; Smith, K.S. )

    1993-01-01

    Light water reactor (LWR) cores containing highly enriched ([ge] 10% Pu) mixed-oxide (MOX) fuel exhibit steep thermal flux gradients near MOX-UO[sub 2] assembly interfaces. The fourth-order polynomial representation of the internodal flux used in many polynomial nodal methods (including the QPANDA nodal model in the SIMULATE-3 core analysis code) has already been verified against low-enriched MOX fuel but cannot accurately portray the severe flux variations near highly enriched MOX interfaces. This paper describes the development of an enhanced nodal model that includes transcendental components in the thermal flux profile.

  16. Increased frequency and suppressive activity of CD127(low/-) regulatory T cells in the peripheral circulation of patients with head and neck squamous cell carcinoma are associated with advanced stage and nodal involvement.

    PubMed

    Drennan, Samantha; Stafford, Nicholas D; Greenman, John; Green, Victoria L

    2013-11-01

    The presence of regulatory T (Treg) cells is thought to be an important mechanism by which head and neck squamous cell carcinoma (HNSCC) successfully evades the immune system. Using multicolour flow cytometry, the frequency and functional capacity of two CD4(+)  CD127(low/-) Treg cell populations, separated on the basis of different levels of CD25 expression (CD25(inter) and CD25(high) ), from the peripheral circulation of newly presenting HNSCC patients were assessed with regard to clinicopathological features and healthy controls. The frequency of circulating Treg cells was similar between HNSCC patients and healthy controls, and for patients with HNSCC developing from different subsites (laryngeal compared with oropharyngeal). However, patients with advanced stage tumours and those with nodal involvement had significantly elevated levels of CD4(+)  CD25(high)  CD127(low/-) Treg cells compared with patients who had early stage tumours (P = 0·03) and those without nodal involvement (P = 0·03), respectively. CD4(+)  CD25(high)  CD127(low/-) Treg cells from the entire HNSCC patient cohort and from patients whose tumours had metastasized to the lymph nodes were also shown to suppress the proliferation of effector T cells significantly more, compared with those from healthy controls (P = 0·04) or patients with no nodal involvement (P = 0·04). Additionally, CD4(+)  CD25(inter)  CD127(low/-) Treg cells consistently induced greater suppressive activity than CD4(+)  CD25(high)  CD127(low/-) Treg cells on the proliferation of the effector T-cell populations (CD4(+)  CD25(-)  CD127(-/+) and CD4(+)  CD25(+)  CD127(+) ). Peripheral Treg cells, identified by the CD127(low/-) phenotype, have been shown to be influenced by a patient's tumour stage and/or nodal status in HNSCC; suggesting a role in tumour progression that could be manipulated by future immunotherapy.

  17. Code System to Solve the Few-Group Neutron Diffusion Equation Utilizing the Nodal Expansion Method (NEM) for Eigenvalue, Adjoint, and Fixed-Source

    2004-04-21

    Version 04 NESTLE solves the few-group neutron diffusion equation utilizing the NEM. The NESTLE code can solve the eigenvalue (criticality), eigenvalue adjoint, external fixed-source steady-state, and external fixed-source or eigenvalue initiated transient problems. The eigenvalue problem allows criticality searches to be completed, and the external fixed-source steady-state problem can search to achieve a specified power level. Transient problems model delayed neutrons via precursor groups. Several core properties can be input as time dependent. Two- ormore » four-energy groups can be utilized, with all energy groups being thermal groups (i.e., upscatter exits) if desired. Core geometries modeled include Cartesian and hexagonal. Three-, two-, and one-dimensional models can be utilized with various symmetries. The thermal conditions predicted by the thermal-hydraulic model of the core are used to correct cross sections for temperature and density effects. Cross sections are parameterized by color, control rod state (i.e., in or out), and burnup, allowing fuel depletion to be modeled. Either a macroscopic or microscopic model may be employed.« less

  18. The H.264/MPEG4 advanced video coding

    NASA Astrophysics Data System (ADS)

    Gromek, Artur

    2009-06-01

    H.264/MPEG4-AVC is the newest video coding standard recommended by International Telecommunication Union - Telecommunication Standardization Section (ITU-T) and the ISO/IEC Moving Picture Expert Group (MPEG). The H.264/MPEG4-AVC has recently become leading standard for generic audiovisual services, since deployment for digital television. Nowadays is commonly used in wide range of video application ranging like mobile services, videoconferencing, IPTV, HDTV, video storage and many more. In this article, author briefly describes the technology applied in the H.264/MPEG4-AVC video coding standard, the way of real-time implementation and the way of future development.

  19. Recent advances in genetic code engineering in Escherichia coli.

    PubMed

    Hoesl, Michael Georg; Budisa, Nediljko

    2012-10-01

    The expansion of the genetic code is gradually becoming a core discipline in Synthetic Biology. It offers the best possible platform for the transfer of numerous chemical reactions and processes from the chemical synthetic laboratory into the biochemistry of living cells. The incorporation of biologically occurring or chemically synthesized non-canonical amino acids into recombinant proteins and even proteomes via reprogrammed protein translation is in the heart of these efforts. Orthogonal pairs consisting of aminoacyl-tRNA synthetase and its cognate tRNA proved to be a general tool for the assignment of certain codons of the genetic code with a maximum degree of chemical liberty. Here, we highlight recent developments that should provide a solid basis for the development of generalist tools enabling a controlled variation of chemical composition in proteins and even proteomes. This will take place in the frame of a greatly expanded genetic code with emancipated codons liberated from the current function or with totally new coding units.

  20. Coded aperture Fast Neutron Analysis: Latest design advances

    NASA Astrophysics Data System (ADS)

    Accorsi, Roberto; Lanza, Richard C.

    2001-07-01

    Past studies have showed that materials of concern like explosives or narcotics can be identified in bulk from their atomic composition. Fast Neutron Analysis (FNA) is a nuclear method capable of providing this information even when considerable penetration is needed. Unfortunately, the cross sections of the nuclear phenomena and the solid angles involved are typically small, so that it is difficult to obtain high signal-to-noise ratios in short inspection times. CAFNAaims at combining the compound specificity of FNA with the potentially high SNR of Coded Apertures, an imaging method successfully used in far-field 2D applications. The transition to a near-field, 3D and high-energy problem prevents a straightforward application of Coded Apertures and demands a thorough optimization of the system. In this paper, the considerations involved in the design of a practical CAFNA system for contraband inspection, its conclusions, and an estimate of the performance of such a system are presented as the evolution of the ideas presented in previous expositions of the CAFNA concept.

  1. An Advanced simulation Code for Modeling Inductive Output Tubes

    SciTech Connect

    Thuc Bui; R. Lawrence Ives

    2012-04-27

    During the Phase I program, CCR completed several major building blocks for a 3D large signal, inductive output tube (IOT) code using modern computer language and programming techniques. These included a 3D, Helmholtz, time-harmonic, field solver with a fully functional graphical user interface (GUI), automeshing and adaptivity. Other building blocks included the improved electrostatic Poisson solver with temporal boundary conditions to provide temporal fields for the time-stepping particle pusher as well as the self electric field caused by time-varying space charge. The magnetostatic field solver was also updated to solve for the self magnetic field caused by time changing current density in the output cavity gap. The goal function to optimize an IOT cavity was also formulated, and the optimization methodologies were investigated.

  2. Three-dimensional transport with variational nodal methods

    SciTech Connect

    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.

  3. The AN neutron transport by nodal diffusion

    SciTech Connect

    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)

  4. ASPECT: An advanced specified-profile evaluation code for tokamaks

    SciTech Connect

    Stotler, D.P.; Reiersen, W.T.; Bateman, G.

    1993-03-01

    A specified-profile, global analysis code has been developed to evaluate the performance of fusion reactor designs. Both steady-state and time-dependent calculations are carried out; the results of the former can be used in defining the parameters of the latter, if desired. In the steady-state analysis, the performance is computed at a density and temperature chosen to be consistent with input limits (e.g., density and beta) of several varieties. The calculation can be made at either the intersection of the two limits or at the point of optimum performance as the density and temperature are varied along the limiting boundaries. Two measures of performance are available for this purpose: the ignition margin or the confinement level required to achieve a prescribed ignition margin. The time-dependent calculation can be configured to yield either the evolution of plasma energy as a function of time or, via an iteration scheme, the amount of auxiliary power required to achieve a desired final plasma energy.

  5. THEHYCO-3DT: Thermal hydrodynamic code for the 3 dimensional transient calculation of advanced LMFBR core

    SciTech Connect

    Vitruk, S.G.; Korsun, A.S.; Ushakov, P.A.

    1995-09-01

    The multilevel mathematical model of neutron thermal hydrodynamic processes in a passive safety core without assemblies duct walls and appropriate computer code SKETCH, consisted of thermal hydrodynamic module THEHYCO-3DT and neutron one, are described. A new effective discretization technique for energy, momentum and mass conservation equations is applied in hexagonal - z geometry. The model adequacy and applicability are presented. The results of the calculations show that the model and the computer code could be used in conceptual design of advanced reactors.

  6. Micromechanics Based Design/Analysis Codes for Advanced Composites

    NASA Technical Reports Server (NTRS)

    Mital, Subodh K.; Murthy, Pappu L. N.; Gyekenyesi, John P.

    2002-01-01

    Advanced high temperature Ceramic Matrix Composites (CMC) hold an enormous potential for use in aero and space related applications specifically for propulsion system components. Consequently, this has led to a multitude of research activities pertaining to fabrication, testing and modeling of these materials. The efforts directed at the development of ceramic matrix composites have focused primarily on improving the properties of the constituents as individual phases. It has, however, become increasingly clear that for CMC to be successfully employed in high temperature applications, research and development efforts should also focus on optimizing the synergistic performance of the constituent phases within the as-produced microstructure of the complex shaped CMC part. Despite their attractive features, the introduction of these materials in a wide spectrum of applications has been excruciatingly slow. The reasons are the high costs associated with the manufacturing and a complete experimental testing and characterization of these materials. Often designers/analysts do not have a consistent set of necessary properties and design allowables to be able to confidently design and analyze structural components made from these composites. Furthermore, the anisotropy of these materials accentuates the burden both on the test engineers and the designers by requiring a vastly increased amount of data/characterization compared to conventional materials.

  7. The Modeling of Advanced BWR Fuel Designs with the NRC Fuel Depletion Codes PARCS/PATHS

    SciTech Connect

    Ward, Andrew; Downar, Thomas J.; Xu, Y.; March-Leuba, Jose A; Thurston, Carl; Hudson, Nathanael H.; Ireland, A.; Wysocki, A.

    2015-04-22

    The PATHS (PARCS Advanced Thermal Hydraulic Solver) code was developed at the University of Michigan in support of U.S. Nuclear Regulatory Commission research to solve the steady-state, two-phase, thermal-hydraulic equations for a boiling water reactor (BWR) and to provide thermal-hydraulic feedback for BWR depletion calculations with the neutronics code PARCS (Purdue Advanced Reactor Core Simulator). The simplified solution methodology, including a three-equation drift flux formulation and an optimized iteration scheme, yields very fast run times in comparison to conventional thermal-hydraulic systems codes used in the industry, while still retaining sufficient accuracy for applications such as BWR depletion calculations. Lastly, the capability to model advanced BWR fuel designs with part-length fuel rods and heterogeneous axial channel flow geometry has been implemented in PATHS, and the code has been validated against previously benchmarked advanced core simulators as well as BWR plant and experimental data. We describe the modifications to the codes and the results of the validation in this paper.

  8. The Modeling of Advanced BWR Fuel Designs with the NRC Fuel Depletion Codes PARCS/PATHS

    DOE PAGES

    Ward, Andrew; Downar, Thomas J.; Xu, Y.; March-Leuba, Jose A; Thurston, Carl; Hudson, Nathanael H.; Ireland, A.; Wysocki, A.

    2015-04-22

    The PATHS (PARCS Advanced Thermal Hydraulic Solver) code was developed at the University of Michigan in support of U.S. Nuclear Regulatory Commission research to solve the steady-state, two-phase, thermal-hydraulic equations for a boiling water reactor (BWR) and to provide thermal-hydraulic feedback for BWR depletion calculations with the neutronics code PARCS (Purdue Advanced Reactor Core Simulator). The simplified solution methodology, including a three-equation drift flux formulation and an optimized iteration scheme, yields very fast run times in comparison to conventional thermal-hydraulic systems codes used in the industry, while still retaining sufficient accuracy for applications such as BWR depletion calculations. Lastly, themore » capability to model advanced BWR fuel designs with part-length fuel rods and heterogeneous axial channel flow geometry has been implemented in PATHS, and the code has been validated against previously benchmarked advanced core simulators as well as BWR plant and experimental data. We describe the modifications to the codes and the results of the validation in this paper.« less

  9. Compiled reports on the applicability of selected codes and standards to advanced reactors

    SciTech Connect

    Benjamin, E.L.; Hoopingarner, K.R.; Markowski, F.J.; Mitts, T.M.; Nickolaus, J.R.; Vo, T.V.

    1994-08-01

    The following papers were prepared for the Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory Commission under contract DE-AC06-76RLO-1830 NRC FIN L2207. This project, Applicability of Codes and Standards to Advance Reactors, reviewed selected mechanical and electrical codes and standards to determine their applicability to the construction, qualification, and testing of advanced reactors and to develop recommendations as to where it might be useful and practical to revise them to suit the (design certification) needs of the NRC.

  10. Observations Regarding Use of Advanced CFD Analysis, Sensitivity Analysis, and Design Codes in MDO

    NASA Technical Reports Server (NTRS)

    Newman, Perry A.; Hou, Gene J. W.; Taylor, Arthur C., III

    1996-01-01

    Observations regarding the use of advanced computational fluid dynamics (CFD) analysis, sensitivity analysis (SA), and design codes in gradient-based multidisciplinary design optimization (MDO) reflect our perception of the interactions required of CFD and our experience in recent aerodynamic design optimization studies using CFD. Sample results from these latter studies are summarized for conventional optimization (analysis - SA codes) and simultaneous analysis and design optimization (design code) using both Euler and Navier-Stokes flow approximations. The amount of computational resources required for aerodynamic design using CFD via analysis - SA codes is greater than that required for design codes. Thus, an MDO formulation that utilizes the more efficient design codes where possible is desired. However, in the aerovehicle MDO problem, the various disciplines that are involved have different design points in the flight envelope; therefore, CFD analysis - SA codes are required at the aerodynamic 'off design' points. The suggested MDO formulation is a hybrid multilevel optimization procedure that consists of both multipoint CFD analysis - SA codes and multipoint CFD design codes that perform suboptimizations.

  11. International Code Assessment and Applications Program: Summary of code assessment studies concerning RELAP5/MOD2, RELAP5/MOD3, and TRAC-B. International Agreement Report

    SciTech Connect

    Schultz, R.R.

    1993-12-01

    Members of the International Code Assessment Program (ICAP) have assessed the US Nuclear Regulatory Commission (USNRC) advanced thermal-hydraulic codes over the past few years in a concerted effort to identify deficiencies, to define user guidelines, and to determine the state of each code. The results of sixty-two code assessment reviews, conducted at INEL, are summarized. Code deficiencies are discussed and user recommended nodalizations investigated during the course of conducting the assessment studies and reviews are listed. All the work that is summarized was done using the RELAP5/MOD2, RELAP5/MOD3, and TRAC-B codes.

  12. Variational nodal solution algorithms for multigroup criticality problems

    SciTech Connect

    Carrico, C.B.; Lewis, E.E.

    1991-01-01

    Variational nodal transport methods are generalized for the treatment of multigroup criticality problems. The generation of variational response matrices is streamlined and automated through the use of symbolic manipulation. A new red-black partitioned matrix algorithm for the solution of the within-group equations is formulated and shown to be at once both a regular matrix splitting and a synthetic acceleration method. The methods are implemented in X- Y geometry as a module of the Argonne National Laboratory code DIF3D. For few group problems highly accurate P[sub 3] eigenvalues are obtained with computing times comparable to those of an existing interface-current nodal transport method.

  13. Grammar Coding in the "Oxford Advanced Learner's Dictionary of Current English."

    ERIC Educational Resources Information Center

    Wekker, Herman

    1992-01-01

    Focuses on the revised system of grammar coding for verbs in the fourth edition of the "Oxford Advanced Learner's Dictionary of Current English" (OALD4), comparing it with two other similar dictionaries. It is shown that the OALD4 is found to be more favorable on many criteria than the other comparable dictionaries. (16 references) (VWL)

  14. A Multi-institutional Investigation of the Prognostic Value of Lymph Nodal Yield in Advanced Stage Oral Cavity Squamous Cell Carcinoma (OCSCC)

    PubMed Central

    Jaber, James J.; Zender, Chad A.; Mehta, Vikas; Davis, Kara; Ferris, Robert L.; Lavertu, Pierre; Rezaee, Rod; Feustel, Paul J.

    2014-01-01

    Background Although existing literature provides surgical recommendations for treating occult disease (cN0) in early stage oral cavity squamous cell carcinoma, a focus on late stage OCSCC is less pervasive. Methods The records of 162 late stage OCSCC pN0 individuals that underwent primary neck dissections were reviewed. Lymph node yield (LNY) as a prognosticator was examined. Results Despite being staged pN0, patients that had a higher LNY had an improved regional/distant control rates, DFS, DSS, and OS. LNY consistently outperformed all other standard variables as being the single best prognostic factor with a tight risk ratio range (RR = 0.95–0.98) even when correcting for the number of lymph nodes examined. Conclusion The results of this study showed that lower regional recurrence rates and improved survival outcomes were seen as lymph node yield increased for advanced T-stage OCSCC pN0. This suggests that increasing lymph node yield with an extended cervical lymphadenectomy may result in lower recurrence rates and improved survival outcomes for this advanced stage group. PMID:24038739

  15. Energy balance in advanced audio coding encoder bit-distortion loop algorithm

    NASA Astrophysics Data System (ADS)

    Brzuchalski, Grzegorz; Pastuszak, Grzegorz

    2013-10-01

    The paper presents two techniques of balancing energy in ScaleFactor bands for Advanced Audio Coding. The techniques allows the AAC encoder to get a better audio quality. The first one modifies Scale Factors assigned to each band after the quantization whereas the second finds and changes offsets in the quantization - just before rounding down. The implementations of the algorithms have been tested and results discussed. Results show that these techniques significantly improve the quality. At last hardware implementation possibilities are discussed.

  16. Advanced Design of Dumbbell-shaped Genetic Minimal Vectors Improves Non-coding and Coding RNA Expression.

    PubMed

    Jiang, Xiaoou; Yu, Han; Teo, Cui Rong; Tan, Genim Siu Xian; Goh, Sok Chin; Patel, Parasvi; Chua, Yiqiang Kevin; Hameed, Nasirah Banu Sahul; Bertoletti, Antonio; Patzel, Volker

    2016-09-01

    Dumbbell-shaped DNA minimal vectors lacking nontherapeutic genes and bacterial sequences are considered a stable, safe alternative to viral, nonviral, and naked plasmid-based gene-transfer systems. We investigated novel molecular features of dumbbell vectors aiming to reduce vector size and to improve the expression of noncoding or coding RNA. We minimized small hairpin RNA (shRNA) or microRNA (miRNA) expressing dumbbell vectors in size down to 130 bp generating the smallest genetic expression vectors reported. This was achieved by using a minimal H1 promoter with integrated transcriptional terminator transcribing the RNA hairpin structure around the dumbbell loop. Such vectors were generated with high conversion yields using a novel protocol. Minimized shRNA-expressing dumbbells showed accelerated kinetics of delivery and transcription leading to enhanced gene silencing in human tissue culture cells. In primary human T cells, minimized miRNA-expressing dumbbells revealed higher stability and triggered stronger target gene suppression as compared with plasmids and miRNA mimics. Dumbbell-driven gene expression was enhanced up to 56- or 160-fold by implementation of an intron and the SV40 enhancer compared with control dumbbells or plasmids. Advanced dumbbell vectors may represent one option to close the gap between durable expression that is achievable with integrating viral vectors and short-term effects triggered by naked RNA. PMID:27357627

  17. Progress and applications of the variational nodal method

    SciTech Connect

    Carrico, C.B.; Palmiotti, G.; Lewis, E.E.

    1995-07-01

    This paper summarizes current progress and developments with the variational nodal method(VNM) and its implementaion within the DIF3D code suite. After a brief development of the mathematical basis for the VNM, results from two three-dimensional benchmarks are presented for a variety of computers. Then current applications of the VNM are discussed including diffusion theory calculations, burnup calculations, highly heterogeneous cores, higher-order spherical harmonics approximations, perturbation theory and heterogeneous nodes.

  18. Advances and future needs in particle production and transport code developments

    SciTech Connect

    Mokhov, N.V.; /Fermilab

    2009-12-01

    The next generation of accelerators and ever expanding needs of existing accelerators demand new developments and additions to Monte-Carlo codes, with an emphasis on enhanced modeling of elementary particle and heavy-ion interactions and transport. Challenges arise from extremely high beam energies and beam power, increasing complexity of accelerators and experimental setups, as well as design, engineering and performance constraints. All these put unprecedented requirements on the accuracy of particle production predictions, the capability and reliability of the codes used in planning new accelerator facilities and experiments, the design of machine, target and collimation systems, detectors and radiation shielding and minimization of their impact on environment. Recent advances in widely-used general-purpose all-particle codes are described for the most critical modules such as particle production event generators, elementary particle and heavy ion transport in an energy range which spans up to 17 decades, nuclide inventory and macroscopic impact on materials, and dealing with complex geometry of accelerator and detector structures. Future requirements for developing physics models and Monte-Carlo codes are discussed.

  19. Application of advanced computational codes in the design of an experiment for a supersonic throughflow fan rotor

    NASA Technical Reports Server (NTRS)

    Wood, Jerry R.; Schmidt, James F.; Steinke, Ronald J.; Chima, Rodrick V.; Kunik, William G.

    1987-01-01

    Increased emphasis on sustained supersonic or hypersonic cruise has revived interest in the supersonic throughflow fan as a possible component in advanced propulsion systems. Use of a fan that can operate with a supersonic inlet axial Mach number is attractive from the standpoint of reducing the inlet losses incurred in diffusing the flow from a supersonic flight Mach number to a subsonic one at the fan face. The design of the experiment using advanced computational codes to calculate the components required is described. The rotor was designed using existing turbomachinery design and analysis codes modified to handle fully supersonic axial flow through the rotor. A two-dimensional axisymmetric throughflow design code plus a blade element code were used to generate fan rotor velocity diagrams and blade shapes. A quasi-three-dimensional, thin shear layer Navier-Stokes code was used to assess the performance of the fan rotor blade shapes. The final design was stacked and checked for three-dimensional effects using a three-dimensional Euler code interactively coupled with a two-dimensional boundary layer code. The nozzle design in the expansion region was analyzed with a three-dimensional parabolized viscous code which corroborated the results from the Euler code. A translating supersonic diffuser was designed using these same codes.

  20. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    SciTech Connect

    Schultz, Peter Andrew

    2011-12-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  1. Advanced Pellet-Cladding Interaction Modeling using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect

    Montgomery, Robert O.; Capps, Nathan A.; Sunderland, Dion J.; Liu, Wenfeng; Hales, Jason; Stanek, Chris; Wirth, Brian D.

    2014-06-15

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermo-mechanical-chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  2. Advanced Pellet Cladding Interaction Modeling Using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect

    Jason Hales; Various

    2014-06-01

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermomechanical- chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  3. The COPERNIC3 project: how AREVA is successfully developing an advanced global fuel rod performance code

    SciTech Connect

    Garnier, Ch.; Mailhe, P.; Sontheimer, F.; Landskron, H.; Deuble, D.; Arimescu, V.I.; Billaux, M.

    2007-07-01

    Fuel performance is a key factor for minimizing operating costs in nuclear plants. One of the important aspects of fuel performance is fuel rod design, based upon reliable tools able to verify the safety of current fuel solutions, prevent potential issues in new core managements and guide the invention of tomorrow's fuels. AREVA is developing its future global fuel rod code COPERNIC3, which is able to calculate the thermal-mechanical behavior of advanced fuel rods in nuclear plants. Some of the best practices to achieve this goal are described, by reviewing the three pillars of a fuel rod code: the database, the modelling and the computer and numerical aspects. At first, the COPERNIC3 database content is described, accompanied by the tools developed to effectively exploit the data. Then is given an overview of the main modelling aspects, by emphasizing the thermal, fission gas release and mechanical sub-models. In the last part, numerical solutions are detailed in order to increase the computational performance of the code, with a presentation of software configuration management solutions. (authors)

  4. Advancing Kohlberg through Codes: Using Professional Codes To Reach the Moral Reasoning Objective in Undergraduate Ethics Courses.

    ERIC Educational Resources Information Center

    Whitehouse, Ginny; Ingram, Michael T.

    The development of moral reasoning as a key course objective in undergraduate communication ethics classes can be accomplished by the critical and deliberate introduction of professional codes of ethics and the internalization of values found in those codes. Notably, "fostering moral reasoning skills" and "surveying current ethical practice" were…

  5. Off-diagonal Jacobian support for Nodal BCs

    SciTech Connect

    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 \

  6. Occult nodal metastasis in solid carcinomata

    SciTech Connect

    Moloy, P.J.; Nicolson, G.L.

    1987-01-01

    This book contains 23 selections. Some of the titles are: Rationale for radiotherapy in subclinical nodal disease; rationale of chemotherapy for nodal disease: The stabilization of topoisomerase II-DNA complexes as a mechanism of antineoplastic drug action; magnetic resonance imaging of malignant cervical adenopathy; and local and regional immune function in cancer patients.

  7. Heterogeneous treatment in the variational nodal method

    SciTech Connect

    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.

  8. Development and Validation of ARKAS cellule: An Advanced Core-Bowing Analysis Code for Fast Reactors

    SciTech Connect

    Ohta, Hirokazu; Yokoo, Takeshi; Nakagawa, Masatoshi; Matsuyama, Shinichiro

    2004-05-15

    An advanced analysis code, ARKAS cellule, has been developed to determine the core distortion and the mechanical behavior of fast reactors. In this code, each hexagonal subassembly duct is represented by a folded thin plate structure divided into a user-specified number of shell elements so that the interduct contact forms and the cross-sectional distortion effect of each duct are properly taken into account. In this paper, the numerical model of the ARKAS cellule code is introduced, and the analytical results for two validation problems are presented. From a single duct compaction analysis, the first validation problem, it is clarified that the new analytical model is applicable to simulating the change of duct compaction stiffness that depends on the loading conditions such as the loading pad forms and the number of contact faces. The second validation analysis has been conducted by comparison with the experimental values obtained by the National Nuclear Corporation Limited in the United Kingdom using the core restraint uniplanar experimental rig (CRUPER), an ex-reactor rig in which a cluster of 91 short ducts is compressed by 30 movable peripheral rams toward the center of the cluster in seven stages. The analysis clarified that the predictions obtained using ARKAS cellule agree well with the measured ram loads and interwrapper gap widths during the compaction sequence. One may conclude that ARKAS cellule is valid for quantitative analysis of the core mechanical behavior and will be particularly useful for the evaluation of transient deformation of core assemblies during accidents in which the distortion of loading pads have important effects on obtaining favorable reactivity feedback.

  9. A Complex-Geometry Validation Experiment for Advanced Neutron Transport Codes

    SciTech Connect

    David W. Nigg; Anthony W. LaPorta; Joseph W. Nielsen; James Parry; Mark D. DeHart; Samuel E. Bays; William F. Skerjanc

    2013-11-01

    The Idaho National Laboratory (INL) has initiated a focused effort to upgrade legacy computational reactor physics software tools and protocols used for support of core fuel management and experiment management in the Advanced Test Reactor (ATR) and its companion critical facility (ATRC) at the INL.. This will be accomplished through the introduction of modern high-fidelity computational software and protocols, with appropriate new Verification and Validation (V&V) protocols, over the next 12-18 months. Stochastic and deterministic transport theory based reactor physics codes and nuclear data packages that support this effort include MCNP5[1], SCALE/KENO6[2], HELIOS[3], SCALE/NEWT[2], and ATTILA[4]. Furthermore, a capability for sensitivity analysis and uncertainty quantification based on the TSUNAMI[5] system has also been implemented. Finally, we are also evaluating the Serpent[6] and MC21[7] codes, as additional verification tools in the near term as well as for possible applications to full three-dimensional Monte Carlo based fuel management modeling in the longer term. On the experimental side, several new benchmark-quality code validation measurements based on neutron activation spectrometry have been conducted using the ATRC. Results for the first four experiments, focused on neutron spectrum measurements within the Northwest Large In-Pile Tube (NW LIPT) and in the core fuel elements surrounding the NW LIPT and the diametrically opposite Southeast IPT have been reported [8,9]. A fifth, very recent, experiment focused on detailed measurements of the element-to-element core power distribution is summarized here and examples of the use of the measured data for validation of corresponding MCNP5, HELIOS, NEWT, and Serpent computational models using modern least-square adjustment methods are provided.

  10. Non-coding RNAs deregulation in oral squamous cell carcinoma: advances and challenges.

    PubMed

    Yu, T; Li, C; Wang, Z; Liu, K; Xu, C; Yang, Q; Tang, Y; Wu, Y

    2016-05-01

    Oral squamous cell carcinoma (OSCC) is a common cause of cancer death. Despite decades of improvements in exploring new treatments and considerable advance in multimodality treatment, satisfactory curative rates have not yet been reached. The difficulty of early diagnosis and the high prevalence of metastasis associated with OSCC contribute to its dismal prognosis. In the last few decades the emerging data from both tumor biology and clinical trials led to growing interest in the research for predictive biomarkers. Non-coding RNAs (ncRNAs) are promising biomarkers. Among numerous kinds of ncRNAs, short ncRNAs, such as microRNAs (miRNAs), have been extensively investigated with regard to their biogenesis, function, and importance in carcinogenesis. In contrast to miRNAs, long non-coding RNAs (lncRNAs) are much less known concerning their functions in human cancers especially in OSCC. The present review highlighted the roles of miRNAs and newly discovered lncRNAs in oral tumorigenesis, metastasis, and their clinical implication.

  11. Assessment of SFR fuel pin performance codes under advanced fuel for minor actinide transmutation

    SciTech Connect

    Bouineau, V.; Lainet, M.; Chauvin, N.; Pelletier, M.

    2013-07-01

    Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is, therefore, an option for the reduction of radiotoxicity and residual power packages as well as the repository area. In the SUPERFACT Experiment four different oxide fuels containing high and low concentrations of {sup 237}Np and {sup 241}Am, representing the homogeneous and heterogeneous in-pile recycling concepts, were irradiated in the PHENIX reactor. The behavior of advanced fuel materials with minor actinide needs to be fully characterized, understood and modeled in order to optimize the design of this kind of fuel elements and to evaluate its performances. This paper assesses the current predictability of fuel performance codes TRANSURANUS and GERMINAL V2 on the basis of post irradiation examinations of the SUPERFACT experiment for pins with low minor actinide content. Their predictions have been compared to measured data in terms of geometrical changes of fuel and cladding, fission gases behavior and actinide and fission product distributions. The results are in good agreement with the experimental results, although improvements are also pointed out for further studies, especially if larger content of minor actinide will be taken into account in the codes. (authors)

  12. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    SciTech Connect

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are

  13. An Extension of the Athena++ Code Framework for GRMHD Based on Advanced Riemann Solvers and Staggered-mesh Constrained Transport

    NASA Astrophysics Data System (ADS)

    White, Christopher J.; Stone, James M.; Gammie, Charles F.

    2016-08-01

    We present a new general relativistic magnetohydrodynamics (GRMHD) code integrated into the Athena++ framework. Improving upon the techniques used in most GRMHD codes, ours allows the use of advanced, less diffusive Riemann solvers, in particular HLLC and HLLD. We also employ a staggered-mesh constrained transport algorithm suited for curvilinear coordinate systems in order to maintain the divergence-free constraint of the magnetic field. Our code is designed to work with arbitrary stationary spacetimes in one, two, or three dimensions, and we demonstrate its reliability through a number of tests. We also report on its promising performance and scalability.

  14. Recent advances in coding theory for near error-free communications

    NASA Technical Reports Server (NTRS)

    Cheung, K.-M.; Deutsch, L. J.; Dolinar, S. J.; Mceliece, R. J.; Pollara, F.; Shahshahani, M.; Swanson, L.

    1991-01-01

    Channel and source coding theories are discussed. The following subject areas are covered: large constraint length convolutional codes (the Galileo code); decoder design (the big Viterbi decoder); Voyager's and Galileo's data compression scheme; current research in data compression for images; neural networks for soft decoding; neural networks for source decoding; finite-state codes; and fractals for data compression.

  15. Final Report, NERI Project: ''An Innovative Reactor Analysis Methodology Based on a Quasidiffusion Nodal Core Model''

    SciTech Connect

    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.

  16. Approximate Schur complement preconditioning of the lowest order nodal discretizations

    SciTech Connect

    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.

  17. Intercode Advanced Fuels and Cladding Comparison Using BISON, FRAPCON, and FEMAXI Fuel Performance Codes

    NASA Astrophysics Data System (ADS)

    Rice, Aaren

    As part of the Department of Energy's Accident Tolerant Fuels (ATF) campaign, new cladding designs and fuel types are being studied in order to help make nuclear energy a safer and more affordable source for power. This study focuses on the implementation and analysis of the SiC cladding and UN, UC, and U3Si2 fuels into three specific nuclear fuel performance codes: BISON, FRAPCON, and FEMAXI. These fuels boast a higher thermal conductivity and uranium density than traditional UO2 fuel which could help lead to longer times in a reactor environment. The SiC cladding has been studied for its reduced production of hydrogen gas during an accident scenario, however the SiC cladding is a known brittle and unyielding material that may fracture during PCMI (Pellet Cladding Mechanical Interaction). This work focuses on steady-state operation with advanced fuel and cladding combinations. By implementing and performing analysis work with these materials, it is possible to better understand some of the mechanical interactions that could be seen as limiting factors. In addition to the analysis of the materials themselves, a further analysis is done on the effects of using a fuel creep model in combination with the SiC cladding. While fuel creep is commonly ignored in the traditional UO2 fuel and Zircaloy cladding systems, fuel creep can be a significant factor in PCMI with SiC.

  18. Advanced turboprop noise prediction: Development of a code at NASA Langley based on recent theoretical results

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Dunn, M. H.; Padula, S. L.

    1986-01-01

    The development of a high speed propeller noise prediction code at Langley Research Center is described. The code utilizes two recent acoustic formulations in the time domain for subsonic and supersonic sources. The structure and capabilities of the code are discussed. Grid size study for accuracy and speed of execution on a computer is also presented. The code is tested against an earlier Langley code. Considerable increase in accuracy and speed of execution are observed. Some examples of noise prediction of a high speed propeller for which acoustic test data are available are given. A brisk derivation of formulations used is given in an appendix.

  19. Modeling Constituent Redistribution in U-Pu-Zr Metallic Fuel Using the Advanced Fuel Performance Code BISON

    SciTech Connect

    Douglas Porter; Steve Hayes; Various

    2014-06-01

    The Advanced Fuels Campaign (AFC) metallic fuels currently being tested have higher zirconium and plutonium concentrations than those tested in the past in EBR reactors. Current metal fuel performance codes have limitations and deficiencies in predicting AFC fuel performance, particularly in the modeling of constituent distribution. No fully validated code exists due to sparse data and unknown modeling parameters. Our primary objective is to develop an initial analysis tool by incorporating state-of-the-art knowledge, constitutive models and properties of AFC metal fuels into the MOOSE/BISON (1) framework in order to analyze AFC metallic fuel tests.

  20. Advancing methods for reliably assessing motivational interviewing fidelity using the motivational interviewing skills code.

    PubMed

    Lord, Sarah Peregrine; Can, Doğan; Yi, Michael; Marin, Rebeca; Dunn, Christopher W; Imel, Zac E; Georgiou, Panayiotis; Narayanan, Shrikanth; Steyvers, Mark; Atkins, David C

    2015-02-01

    The current paper presents novel methods for collecting MISC data and accurately assessing reliability of behavior codes at the level of the utterance. The MISC 2.1 was used to rate MI interviews from five randomized trials targeting alcohol and drug use. Sessions were coded at the utterance-level. Utterance-based coding reliability was estimated using three methods and compared to traditional reliability estimates of session tallies. Session-level reliability was generally higher compared to reliability using utterance-based codes, suggesting that typical methods for MISC reliability may be biased. These novel methods in MI fidelity data collection and reliability assessment provided rich data for therapist feedback and further analyses. Beyond implications for fidelity coding, utterance-level coding schemes may elucidate important elements in the counselor-client interaction that could inform theories of change and the practice of MI.

  1. Keeping a lid on nodal: transcriptional and translational repression of nodal signalling

    PubMed Central

    Robertson, Elizabeth J.

    2016-01-01

    Nodal is an evolutionarily conserved member of the transforming growth factor-β (TGF-β) superfamily of secreted signalling factors. Nodal factors are known to play key roles in embryonic development and asymmetry in a variety of organisms ranging from hydra and sea urchins to fish, mice and humans. In addition to embryonic patterning, Nodal signalling is required for maintenance of human embryonic stem cell pluripotency and mis-regulated Nodal signalling has been found associated with tumour metastases. Therefore, precise and timely regulation of this pathway is essential. Here, we discuss recent evidence from sea urchins, frogs, fish, mice and humans that show a role for transcriptional and translational repression of Nodal signalling during early development. PMID:26791244

  2. Nodal Green’s Function Method Singular Source Term and Burnable Poison Treatment in Hexagonal Geometry

    SciTech Connect

    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.

  3. Ideas for Advancing Code Sharing: A Different Kind of Hack Day

    NASA Astrophysics Data System (ADS)

    Teuben, P.; Allen, A.; Berriman, B.; DuPrie, K.; Hanisch, R. J.; Mink, J.; Nemiroff, R. J.; Shamir, L.; Shortridge, K.; Taylor, M. B.; Wallin, J. F.

    2014-05-01

    How do we as a community encourage the reuse of software for telescope operations, data processing, and ? How can we support making codes used in research available for others to examine? Continuing the discussion from last year Bring out your codes! BoF session, participants separated into groups to brainstorm ideas to mitigate factors which inhibit code sharing and nurture those which encourage code sharing. The BoF concluded with the sharing of ideas that arose from the brainstorming sessions and a brief summary by the moderator.

  4. Nodal Quasiparticle in Pseudogapped Colossal Magnetoresistive Manganites

    SciTech Connect

    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.

  5. Observations on computational methodologies for use in large-scale, gradient-based, multidisciplinary design incorporating advanced CFD codes

    NASA Technical Reports Server (NTRS)

    Newman, P. A.; Hou, G. J.-W.; Jones, H. E.; Taylor, A. C., III; Korivi, V. M.

    1992-01-01

    How a combination of various computational methodologies could reduce the enormous computational costs envisioned in using advanced CFD codes in gradient based optimized multidisciplinary design (MdD) procedures is briefly outlined. Implications of these MdD requirements upon advanced CFD codes are somewhat different than those imposed by a single discipline design. A means for satisfying these MdD requirements for gradient information is presented which appear to permit: (1) some leeway in the CFD solution algorithms which can be used; (2) an extension to 3-D problems; and (3) straightforward use of other computational methodologies. Many of these observations have previously been discussed as possibilities for doing parts of the problem more efficiently; the contribution here is observing how they fit together in a mutually beneficial way.

  6. A Mode Propagation Database Suitable for Code Validation Utilizing the NASA Glenn Advanced Noise Control Fan and Artificial Sources

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2014-01-01

    The NASA Glenn Research Center's Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. A series of tests were performed primarily for the use of code validation and tool validation. Rotating Rake mode measurements were acquired for parametric sets of: (i) mode blockage, (ii) liner insertion loss, (iii) short ducts, and (iv) mode reflection.

  7. A Mode Propagation Database Suitable for Code Validation Utilizing the NASA Glenn Advanced Noise Control Fan and Artificial Sources

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2014-01-01

    The NASA Glenn Research Center's Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. A series of tests were performed primarily for the use of code validation and tool validation. Rotating Rake mode measurements were acquired for parametric sets of: (1) mode blockage, (2) liner insertion loss, (3) short ducts, and (4) mode reflection.

  8. Nodal domains in open microwave systems.

    PubMed

    Kuhl, U; Höhmann, R; Stöckmann, H-J; Gnutzmann, S

    2007-03-01

    Nodal domains are studied both for real psiR and imaginary part psiI of the wave functions of an open microwave cavity and found to show the same behavior as wave functions in closed billiards. In addition we investigate the variation of the number of nodal domains and the signed area correlation by changing the global phase phig according to psiR+ipsiI=eiphig(psiR'+ipsiI'). This variation can be qualitatively, and the correlation quantitatively explained in terms of the phase rigidity characterizing the openness of the billiard.

  9. Nodal domains in open microwave systems

    NASA Astrophysics Data System (ADS)

    Kuhl, U.; Höhmann, R.; Stöckmann, H.-J.; Gnutzmann, S.

    2007-03-01

    Nodal domains are studied both for real ψR and imaginary part ψI of the wave functions of an open microwave cavity and found to show the same behavior as wave functions in closed billiards. In addition we investigate the variation of the number of nodal domains and the signed area correlation by changing the global phase φg according to ψR+iψI=eiφg(ψR'+iψI') . This variation can be qualitatively, and the correlation quantitatively explained in terms of the phase rigidity characterizing the openness of the billiard.

  10. Advanced Subsonic Technology (AST) Area of Interest (AOI) 6: Develop and Validate Aeroelastic Codes for Turbomachinery

    NASA Technical Reports Server (NTRS)

    Gardner, Kevin D.; Liu, Jong-Shang; Murthy, Durbha V.; Kruse, Marlin J.; James, Darrell

    1999-01-01

    AlliedSignal Engines, in cooperation with NASA GRC (National Aeronautics and Space Administration Glenn Research Center), completed an evaluation of recently-developed aeroelastic computer codes using test cases from the AlliedSignal Engines fan blisk and turbine databases. Test data included strain gage, performance, and steady-state pressure information obtained for conditions where synchronous or flutter vibratory conditions were found to occur. Aeroelastic codes evaluated included quasi 3-D UNSFLO (MIT Developed/AE Modified, Quasi 3-D Aeroelastic Computer Code), 2-D FREPS (NASA-Developed Forced Response Prediction System Aeroelastic Computer Code), and 3-D TURBO-AE (NASA/Mississippi State University Developed 3-D Aeroelastic Computer Code). Unsteady pressure predictions for the turbine test case were used to evaluate the forced response prediction capabilities of each of the three aeroelastic codes. Additionally, one of the fan flutter cases was evaluated using TURBO-AE. The UNSFLO and FREPS evaluation predictions showed good agreement with the experimental test data trends, but quantitative improvements are needed. UNSFLO over-predicted turbine blade response reductions, while FREPS under-predicted them. The inviscid TURBO-AE turbine analysis predicted no discernible blade response reduction, indicating the necessity of including viscous effects for this test case. For the TURBO-AE fan blisk test case, significant effort was expended getting the viscous version of the code to give converged steady flow solutions for the transonic flow conditions. Once converged, the steady solutions provided an excellent match with test data and the calibrated DAWES (AlliedSignal 3-D Viscous Steady Flow CFD Solver). However, efforts expended establishing quality steady-state solutions prevented exercising the unsteady portion of the TURBO-AE code during the present program. AlliedSignal recommends that unsteady pressure measurement data be obtained for both test cases examined

  11. A new 3-D integral code for computation of accelerator magnets

    SciTech Connect

    Turner, L.R.; Kettunen, L.

    1991-01-01

    For computing accelerator magnets, integral codes have several advantages over finite element codes; far-field boundaries are treated automatically, and computed field in the bore region satisfy Maxwell's equations exactly. A new integral code employing edge elements rather than nodal elements has overcome the difficulties associated with earlier integral codes. By the use of field integrals (potential differences) as solution variables, the number of unknowns is reduced to one less than the number of nodes. Two examples, a hollow iron sphere and the dipole magnet of Advanced Photon Source injector synchrotron, show the capability of the code. The CPU time requirements are comparable to those of three-dimensional (3-D) finite-element codes. Experiments show that in practice it can realize much of the potential CPU time saving that parallel processing makes possible. 8 refs., 4 figs., 1 tab.

  12. Activin/Nodal signalling before implantation: setting the stage for embryo patterning

    PubMed Central

    Papanayotou, Costis; Collignon, Jérôme

    2014-01-01

    Activins and Nodal are members of the transforming growth factor beta (TGF-β) family of growth factors. Their Smad2/3-dependent signalling pathway is well known for its implication in the patterning of the embryo after implantation. Although this pathway is active early on at preimplantation stages, embryonic phenotypes for loss-of-function mutations of prominent components of the pathway are not detected before implantation. It is only fairly recently that an understanding of the role of the Activin/Nodal signalling pathway at these stages has started to emerge, notably from studies detailing how it controls the expression of target genes in embryonic stem cells. We review here what is currently known of the TGF-β-related ligands that determine the activity of Activin/Nodal signalling at preimplantation stages, and recent advances in the elucidation of the Smad2/3-dependent mechanisms underlying developmental progression. PMID:25349448

  13. Activin/Nodal signalling before implantation: setting the stage for embryo patterning.

    PubMed

    Papanayotou, Costis; Collignon, Jérôme

    2014-12-01

    Activins and Nodal are members of the transforming growth factor beta (TGF-β) family of growth factors. Their Smad2/3-dependent signalling pathway is well known for its implication in the patterning of the embryo after implantation. Although this pathway is active early on at preimplantation stages, embryonic phenotypes for loss-of-function mutations of prominent components of the pathway are not detected before implantation. It is only fairly recently that an understanding of the role of the Activin/Nodal signalling pathway at these stages has started to emerge, notably from studies detailing how it controls the expression of target genes in embryonic stem cells. We review here what is currently known of the TGF-β-related ligands that determine the activity of Activin/Nodal signalling at preimplantation stages, and recent advances in the elucidation of the Smad2/3-dependent mechanisms underlying developmental progression.

  14. Nodal quasiparticle in pseudogapped colossal magnetoresistive manganites

    NASA Astrophysics Data System (ADS)

    Mannella, N.; Yang, W. L.; Zhou, X. J.; Tanaka, K.; Zheng, H.; Mitchell, J. F.; Zaanen, J.; Devereaux, T. P.; Nagaosa, N.; Hussain, Z.; Shen, Z. X.

    2006-03-01

    In this talk, the result of a recent angle-resolved photoemission spectroscopy (ARPES) investigation which allowed elucidating the controversial nature of the ferromagnetic metallic groundstate in the prototypical colossal magnetoresistive manganite bilayer compound La1.2Sr1.8Mn2O7 will be discussed [1]. The distribution of spectral weight in momentum space exhibits a nodal--antinodal dichotomous character. Quasiparticle excitations have been detected for the first time along the nodal direction (i.e. diagonal), and they are found to determine the metallic transport properties of this compound. The weight of the quasiparticle peak diminishes rapidly while crossing over to the antinodal (i.e. parallel to the Mn--O bonds) parallel sections of the Fermi surface, with the spectra strongly resembling those found in heavily underdoped cuprates high temperature superconductors (HTSC) such as Ca2-xNaxCuO2Cl2 [2]. This dichotomy between the electronic excitations along the nodal and antinodal directions in momentum space was so far considered a characteristic unique feature of the copper oxide HTSC. These findings therefore cast doubt on the assumption that the pseudogap state in the cuprate HTSC and the nodal-antinodal dichotomy are hallmarks of the superconductivity state. [1] N. Mannella et al., Nature 438, 474 (2005) [2] K. M Shen et al., Science 307, 901 (2005).

  15. Nodal quasiparticle in pseudogapped colossal magnetoresistivemanganites

    SciTech Connect

    Mannella, Norman; Yang, Wanli L.; Zhou, Xing Jiang; Zheng, Hong; Mitchell, John F.; Zaanen, Jan; Devereaux, Thomas P.; Nagaosa, Naoto; Hussain, Zahid; Shen, Zhi-Xun

    2008-01-17

    A characteristic feature of the copper oxidehigh-temperaturesuperconductors is the dichotomy between the electronicexcitations along the nodal (diagonal) and antinodal (parallel to the CuO bonds) directions in momentum space, generally assumed to be linked tothe 'd-wave' symmetry of the superconducting state. Angle-resolvedphotoemission measurements in the superconducting state have revealed aquasiparticle spectrum with a d-wave gap structure that exhibits amaximum along the antinodal direction and vanishes along the nodaldirection1. Subsequent measurements have shown that, at low dopinglevels, this gap structure persists even in the high-temperature metallicstate, although the nodal points of the superconducting state spread outin finite 'Fermi arcs'2. This is the so-called pseudogap phase, and ithas been assumed that it is closely linked to the superconducting state,either by assigning it to fluctuating superconductivity3 or by invokingorders which are natural competitors of d-wave superconductors4, 5. Herewe report experimental evidence that a very similar pseudogap state witha nodal-antinodal dichotomous character exists in a system that ismarkedly different from a superconductor: the ferromagnetic metallicgroundstate of the colossal magnetoresistive bilayer manganiteLa1.2Sr1.8Mn2O7. Our findings therefore cast doubt on the assumption thatthe pseudogap state in the copper oxides and the nodal-antinodaldichotomy are hallmarks of the superconductivity state.

  16. Optogenetic Control of Nodal Signaling Reveals a Temporal Pattern of Nodal Signaling Regulating Cell Fate Specification during Gastrulation.

    PubMed

    Sako, Keisuke; Pradhan, Saurabh J; Barone, Vanessa; Inglés-Prieto, Álvaro; Müller, Patrick; Ruprecht, Verena; Čapek, Daniel; Galande, Sanjeev; Janovjak, Harald; Heisenberg, Carl-Philipp

    2016-07-19

    During metazoan development, the temporal pattern of morphogen signaling is critical for organizing cell fates in space and time. Yet, tools for temporally controlling morphogen signaling within the embryo are still scarce. Here, we developed a photoactivatable Nodal receptor to determine how the temporal pattern of Nodal signaling affects cell fate specification during zebrafish gastrulation. By using this receptor to manipulate the duration of Nodal signaling in vivo by light, we show that extended Nodal signaling within the organizer promotes prechordal plate specification and suppresses endoderm differentiation. Endoderm differentiation is suppressed by extended Nodal signaling inducing expression of the transcriptional repressor goosecoid (gsc) in prechordal plate progenitors, which in turn restrains Nodal signaling from upregulating the endoderm differentiation gene sox17 within these cells. Thus, optogenetic manipulation of Nodal signaling identifies a critical role of Nodal signaling duration for organizer cell fate specification during gastrulation. PMID:27396324

  17. Advancements and performance of iterative methods in industrial applications codes on CRAY parallel/vector supercomputers

    SciTech Connect

    Poole, G.; Heroux, M.

    1994-12-31

    This paper will focus on recent work in two widely used industrial applications codes with iterative methods. The ANSYS program, a general purpose finite element code widely used in structural analysis applications, has now added an iterative solver option. Some results are given from real applications comparing performance with the tradition parallel/vector frontal solver used in ANSYS. Discussion of the applicability of iterative solvers as a general purpose solver will include the topics of robustness, as well as memory requirements and CPU performance. The FIDAP program is a widely used CFD code which uses iterative solvers routinely. A brief description of preconditioners used and some performance enhancements for CRAY parallel/vector systems is given. The solution of large-scale applications in structures and CFD includes examples from industry problems solved on CRAY systems.

  18. A predictive index of axillary nodal involvement in operable breast cancer.

    PubMed Central

    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

  19. The H.264/AVC advanced video coding standard: overview and introduction to the fidelity range extensions

    NASA Astrophysics Data System (ADS)

    Sullivan, Gary J.; Topiwala, Pankaj N.; Luthra, Ajay

    2004-11-01

    H.264/MPEG-4 AVC is the latest international video coding standard. It was jointly developed by the Video Coding Experts Group (VCEG) of the ITU-T and the Moving Picture Experts Group (MPEG) of ISO/IEC. It uses state-of-the-art coding tools and provides enhanced coding efficiency for a wide range of applications, including video telephony, video conferencing, TV, storage (DVD and/or hard disk based, especially high-definition DVD), streaming video, digital video authoring, digital cinema, and many others. The work on a new set of extensions to this standard has recently been completed. These extensions, known as the Fidelity Range Extensions (FRExt), provide a number of enhanced capabilities relative to the base specification as approved in the Spring of 2003. In this paper, an overview of this standard is provided, including the highlights of the capabilities of the new FRExt features. Some comparisons with the existing MPEG-2 and MPEG-4 Part 2 standards are also provided.

  20. SKIRT: An advanced dust radiative transfer code with a user-friendly architecture

    NASA Astrophysics Data System (ADS)

    Camps, P.; Baes, M.

    2015-03-01

    We discuss the architecture and design principles that underpin the latest version of SKIRT, a state-of-the-art open source code for simulating continuum radiation transfer in dusty astrophysical systems, such as spiral galaxies and accretion disks. SKIRT employs the Monte Carlo technique to emulate the relevant physical processes including scattering, absorption and emission by the dust. The code features a wealth of built-in geometries, radiation source spectra, dust characterizations, dust grids, and detectors, in addition to various mechanisms for importing snapshots generated by hydrodynamical simulations. The configuration for a particular simulation is defined at run-time through a user-friendly interface suitable for both occasional and power users. These capabilities are enabled by careful C++ code design. The programming interfaces between components are well defined and narrow. Adding a new feature is usually as simple as adding another class; the user interface automatically adjusts to allow configuring the new options. We argue that many scientific codes, like SKIRT, can benefit from careful object-oriented design and from a friendly user interface, even if it is not a graphical user interface.

  1. Development and validation of burnup dependent computational schemes for the analysis of assemblies with advanced lattice codes

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Karthikeyan

    The main aim of this research is the development and validation of computational schemes for advanced lattice codes. The advanced lattice code which forms the primary part of this research is "DRAGON Version4". The code has unique features like self shielding calculation with capabilities to represent distributed and mutual resonance shielding effects, leakage models with space-dependent isotropic or anisotropic streaming effect, availability of the method of characteristics (MOC), burnup calculation with reaction-detailed energy production etc. Qualified reactor physics codes are essential for the study of all existing and envisaged designs of nuclear reactors. Any new design would require a thorough analysis of all the safety parameters and burnup dependent behaviour. Any reactor physics calculation requires the estimation of neutron fluxes in various regions of the problem domain. The calculation goes through several levels before the desired solution is obtained. Each level of the lattice calculation has its own significance and any compromise at any step will lead to poor final result. The various levels include choice of nuclear data library and energy group boundaries into which the multigroup library is cast; self shielding of nuclear data depending on the heterogeneous geometry and composition; tracking of geometry, keeping error in volume and surface to an acceptable minimum; generation of regionwise and groupwise collision probabilities or MOC-related information and their subsequent normalization thereof, solution of transport equation using the previously generated groupwise information and obtaining the fluxes and reaction rates in various regions of the lattice; depletion of fuel and of other materials based on normalization with constant power or constant flux. Of the above mentioned levels, the present research will mainly focus on two aspects, namely self shielding and depletion. The behaviour of the system is determined by composition of resonant

  2. 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.

  3. Preface: Recent Advances in Modeling Multiphase Flow and Transportwith the TOUGH Family of Codes

    SciTech Connect

    Liu, Hui-Hai; Illangasekare, Tissa H.

    2007-11-15

    A symposium on research carried out using the TOUGH family of numerical codes was held from May 15 to 17, 2006, at the Lawrence Berkeley National Laboratory. This special issue of the 'Vadose Zone Journal' contains revised and expanded versions of a selected set of papers presented at this symposium (TOUGH Symposium 2006; http://esd.lbl.gov/TOUGHsymposium), all of which focus on multiphase flow, including flow in the vadose zone.

  4. Validation and verification of RELAP5 for Advanced Neutron Source accident analysis: Part I, comparisons to ANSDM and PRSDYN codes

    SciTech Connect

    Chen, N.C.J.; Ibn-Khayat, M.; March-Leuba, J.A.; Wendel, M.W.

    1993-12-01

    As part of verification and validation, the Advanced Neutron Source reactor RELAP5 system model was benchmarked by the Advanced Neutron Source dynamic model (ANSDM) and PRSDYN models. RELAP5 is a one-dimensional, two-phase transient code, developed by the Idaho National Engineering Laboratory for reactor safety analysis. Both the ANSDM and PRSDYN models use a simplified single-phase equation set to predict transient thermal-hydraulic performance. Brief descriptions of each of the codes, models, and model limitations were included. Even though comparisons were limited to single-phase conditions, a broad spectrum of accidents was benchmarked: a small loss-of-coolant-accident (LOCA), a large LOCA, a station blackout, and a reactivity insertion accident. The overall conclusion is that the three models yield similar results if the input parameters are the same. However, ANSDM does not capture pressure wave propagation through the coolant system. This difference is significant in very rapid pipe break events. Recommendations are provided for further model improvements.

  5. Does standardized mega-code training improve the quality of pre-hospital advanced cardiac life support (ACLS)?

    PubMed

    Schneider, T; Mauer, D; Diehl, P; Eberle, B; Dick, W

    1995-04-01

    The aim of our prospective study was to evaluate the effects of a standardized mega-code and arrhythmia training upon process elements of quality of pre-hospital advanced cardiac life support provided by a physician-staffed mobile intensive care unit. In 145 cases of adult cardiac arrest due to cardiac aetiology, time intervals from arrival of the mobile intensive care unit at the patient's side until first ECG diagnosis, first defibrillation, endotracheal intubation, and first epinephrine administration were measured with on-line tape recording, prior to, and following a standardized 8-h arrhythmia and mega-code training. Following the training, patients with asystole or pulseless electrical activity were intubated 1.1 min earlier (P = 0.03), and received epinephrine 1.3 min earlier (P = 0.01) than prior to the training. There were no significant differences in time intervals concerning management of ventricular fibrillation or tachycardia. Neither admission nor discharge rates differed significantly before and after the training. Thus, practical training including rhythm analysis and mega-code session improved the performance of our mobile intensive care unit in cases of asystole and pulseless electrical activity, and, hence, process elements of quality.

  6. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Waste Integrated Performance and Safety Codes (IPSC) : FY10 development and integration.

    SciTech Connect

    Criscenti, Louise Jacqueline; Sassani, David Carl; Arguello, Jose Guadalupe, Jr.; Dewers, Thomas A.; Bouchard, Julie F.; Edwards, Harold Carter; Freeze, Geoffrey A.; Wang, Yifeng; Schultz, Peter Andrew

    2011-02-01

    This report describes the progress in fiscal year 2010 in developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. Waste IPSC activities in fiscal year 2010 focused on specifying a challenge problem to demonstrate proof of concept, developing a verification and validation plan, and performing an initial gap analyses to identify candidate codes and tools to support the development and integration of the Waste IPSC. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. This year-end progress report documents the FY10 status of acquisition, development, and integration of thermal-hydrologic-chemical-mechanical (THCM) code capabilities, frameworks, and enabling tools and infrastructure.

  7. DIF3D nodal neutronics option for two- and three-dimensional diffusion theory calculations in hexagonal geometry. [LMFBR

    SciTech Connect

    Lawrence, R.D.

    1983-03-01

    A nodal method is developed for the solution of the neutron-diffusion equation in two- and three-dimensional hexagonal geometries. The nodal scheme has been incorporated as an option in the finite-difference diffusion-theory code DIF3D, and is intended for use in the analysis of current LMFBR designs. The nodal equations are derived using higher-order polynomial approximations to the spatial dependence of the flux within the hexagonal-z node. The final equations, which are cast in the form of inhomogeneous response-matrix equations for each energy group, involved spatial moments of the node-interior flux distribution plus surface-averaged partial currents across the faces of the node. These equations are solved using a conventional fission-source iteration accelerated by coarse-mesh rebalance and asymptotic source extrapolation. This report describes the mathematical development and numerical solution of the nodal equations, as well as the use of the nodal option and details concerning its programming structure. This latter information is intended to supplement the information provided in the separate documentation of the DIF3D code.

  8. Development and validation of burnup dependent computational schemes for the analysis of assemblies with advanced lattice codes

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Karthikeyan

    The main aim of this research is the development and validation of computational schemes for advanced lattice codes. The advanced lattice code which forms the primary part of this research is "DRAGON Version4". The code has unique features like self shielding calculation with capabilities to represent distributed and mutual resonance shielding effects, leakage models with space-dependent isotropic or anisotropic streaming effect, availability of the method of characteristics (MOC), burnup calculation with reaction-detailed energy production etc. Qualified reactor physics codes are essential for the study of all existing and envisaged designs of nuclear reactors. Any new design would require a thorough analysis of all the safety parameters and burnup dependent behaviour. Any reactor physics calculation requires the estimation of neutron fluxes in various regions of the problem domain. The calculation goes through several levels before the desired solution is obtained. Each level of the lattice calculation has its own significance and any compromise at any step will lead to poor final result. The various levels include choice of nuclear data library and energy group boundaries into which the multigroup library is cast; self shielding of nuclear data depending on the heterogeneous geometry and composition; tracking of geometry, keeping error in volume and surface to an acceptable minimum; generation of regionwise and groupwise collision probabilities or MOC-related information and their subsequent normalization thereof, solution of transport equation using the previously generated groupwise information and obtaining the fluxes and reaction rates in various regions of the lattice; depletion of fuel and of other materials based on normalization with constant power or constant flux. Of the above mentioned levels, the present research will mainly focus on two aspects, namely self shielding and depletion. The behaviour of the system is determined by composition of resonant

  9. A one- and two-dimensional cross-section sensitivity and uncertainty path of the AARE (Advanced Analysis for Reactor Engineering) modular code system

    SciTech Connect

    Davidson, J.W.; Dudziak, D.J.; Higgs, C.E.; Stepanek, J.

    1988-01-01

    AARE, a code package to perform Advanced Analysis for Reactor Engineering, is a linked modular system for fission reactor core and shielding, as well as fusion blanket, analysis. Its cross-section sensitivity and uncertainty path presently includes the cross-section processing and reformatting code TRAMIX, cross-section homogenization and library reformatting code MIXIT, the 1-dimensional transport code ONEDANT, the 2-dimensional transport code TRISM, and the 1- and 2- dimensional cross-section sensitivity and uncertainty code SENSIBL. IN the present work, a short description of the whole AARE system is given, followed by a detailed description of the cross-section sensitivity and uncertainty path. 23 refs., 2 figs.

  10. Advanced Neutron Source Dynamic Model (ANSDM) code description and user guide

    SciTech Connect

    March-Leuba, J.

    1995-08-01

    A mathematical model is designed that simulates the dynamic behavior of the Advanced Neutron Source (ANS) reactor. Its main objective is to model important characteristics of the ANS systems as they are being designed, updated, and employed; its primary design goal, to aid in the development of safety and control features. During the simulations the model is also found to aid in making design decisions for thermal-hydraulic systems. Model components, empirical correlations, and model parameters are discussed; sample procedures are also given. Modifications are cited, and significant development and application efforts are noted focusing on examination of instrumentation required during and after accidents to ensure adequate monitoring during transient conditions.

  11. Euler Technology Assessment - SPLITFLOW Code Applications for Stability and Control Analysis on an Advanced Fighter Model Employing Innovative Control Concepts

    NASA Technical Reports Server (NTRS)

    Jordan, Keith J.

    1998-01-01

    This report documents results from the NASA-Langley sponsored Euler Technology Assessment Study conducted by Lockheed-Martin Tactical Aircraft Systems (LMTAS). The purpose of the study was to evaluate the ability of the SPLITFLOW code using viscous and inviscid flow models to predict aerodynamic stability and control of an advanced fighter model. The inviscid flow model was found to perform well at incidence angles below approximately 15 deg, but not as well at higher angles of attack. The results using a turbulent, viscous flow model matched the trends of the wind tunnel data, but did not show significant improvement over the Euler solutions. Overall, the predictions were found to be useful for stability and control design purposes.

  12. Nodal integral method for transient heat conduction in a cylinder

    SciTech Connect

    Esser, P.D. )

    1993-01-01

    The accuracy and efficiency of nodal solution methods are well established for neutron diffusion in a variety of geometries, as well as for heat transfer and fluid flow in rectangular coordinates. This paper describes the development of a nodal integral method to solve the transient heat conduction equation in cylindrical geometry. Results for a test problem with an analytical solution indicate that the nodal solution provides higher accuracy than a conventional implicit finite difference scheme, while maintaining similar stability characteristics.

  13. Advanced modulation technology development for earth station demodulator applications. Coded modulation system development

    NASA Technical Reports Server (NTRS)

    Miller, Susan P.; Kappes, J. Mark; Layer, David H.; Johnson, Peter N.

    1990-01-01

    A jointly optimized coded modulation system is described which was designed, built, and tested by COMSAT Laboratories for NASA LeRC which provides a bandwidth efficiency of 2 bits/s/Hz at an information rate of 160 Mbit/s. A high speed rate 8/9 encoder with a Viterbi decoder and an Octal PSK modem are used to achieve this. The BER performance is approximately 1 dB from the theoretically calculated value for this system at a BER of 5 E-7 under nominal conditions. The system operates in burst mode for downlink applications and tests have demonstrated very little degradation in performance with frequency and level offset. Unique word miss rate measurements were conducted which demonstrate reliable acquisition at low values of Eb/No. Codec self tests have verified the performance of this subsystem in a stand alone mode. The codec is capable of operation at a 200 Mbit/s information rate as demonstrated using a codec test set which introduces noise digitally. The measured performance is within 0.2 dB of the computer simulated predictions. A gate array implementation of the most time critical element of the high speed Viterbi decoder was completed. This gate array add-compare-select chip significantly reduces the power consumption and improves the manufacturability of the decoder. This chip has general application in the implementation of high speed Viterbi decoders.

  14. Advanced modulation technology development for earth station demodulator applications. Coded modulation system development

    NASA Astrophysics Data System (ADS)

    Miller, Susan P.; Kappes, J. Mark; Layer, David H.; Johnson, Peter N.

    1990-04-01

    A jointly optimized coded modulation system is described which was designed, built, and tested by COMSAT Laboratories for NASA LeRC which provides a bandwidth efficiency of 2 bits/s/Hz at an information rate of 160 Mbit/s. A high speed rate 8/9 encoder with a Viterbi decoder and an Octal PSK modem are used to achieve this. The BER performance is approximately 1 dB from the theoretically calculated value for this system at a BER of 5 E-7 under nominal conditions. The system operates in burst mode for downlink applications and tests have demonstrated very little degradation in performance with frequency and level offset. Unique word miss rate measurements were conducted which demonstrate reliable acquisition at low values of Eb/No. Codec self tests have verified the performance of this subsystem in a stand alone mode. The codec is capable of operation at a 200 Mbit/s information rate as demonstrated using a codec test set which introduces noise digitally. The measured performance is within 0.2 dB of the computer simulated predictions. A gate array implementation of the most time critical element of the high speed Viterbi decoder was completed. This gate array add-compare-select chip significantly reduces the power consumption and improves the manufacturability of the decoder. This chip has general application in the implementation of high speed Viterbi decoders.

  15. Monte-Carlo Code (MCNP) Modeling of the Advanced Test Reactor Applicable to the Mixed Oxide (MOX) Test Irradiation

    SciTech Connect

    G. S. Chang; R. C. Pederson

    2005-07-01

    Mixed oxide (MOX) test capsules prepared with weapons-derived plutonium have been irradiated to a burnup of 50 GWd/t. The MOX fuel was fabricated at Los Alamos National Laboratory by a master-mix process and has been irradiated in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Previous withdrawals of the same fuel have occurred at 9, 21, 30, and 40 GWd/t. Oak Ridge National Laboratory (ORNL) manages this test series for the Department of Energy’s Fissile Materials Disposition Program (FMDP). The fuel burnup analyses presented in this study were performed using MCWO, a welldeveloped tool that couples the Monte Carlo transport code MCNP with the isotope depletion and buildup code ORIGEN-2. MCWO analysis yields time-dependent and neutron-spectrum-dependent minor actinide and Pu concentrations for the ATR small I-irradiation test position. The purpose of this report is to validate both the Weapons-Grade Mixed Oxide (WG-MOX) test assembly model and the new fuel burnup analysis methodology by comparing the computed results against the neutron monitor measurements.

  16. Topological surface states in nodal superconductors.

    PubMed

    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.

  17. An essential role for maternal control of Nodal signaling

    PubMed Central

    Kumari, Pooja; Gilligan, Patrick C; Lim, Shimin; Tran, Long Duc; Winkler, Sylke; Philp, Robin; Sampath, Karuna

    2013-01-01

    Growth factor signaling is essential for pattern formation, growth, differentiation, and maintenance of stem cell pluripotency. Nodal-related signaling factors are required for axis formation and germ layer specification from sea urchins to mammals. Maternal transcripts of the zebrafish Nodal factor, Squint (Sqt), are localized to future embryonic dorsal. The mechanisms by which maternal sqt/nodal RNA is localized and regulated have been unclear. Here, we show that maternal control of Nodal signaling via the conserved Y box-binding protein 1 (Ybx1) is essential. We identified Ybx1 via a proteomic screen. Ybx1 recognizes the 3’ untranslated region (UTR) of sqt RNA and prevents premature translation and Sqt/Nodal signaling. Maternal-effect mutations in zebrafish ybx1 lead to deregulated Nodal signaling, gastrulation failure, and embryonic lethality. Implanted Nodal-coated beads phenocopy ybx1 mutant defects. Thus, Ybx1 prevents ectopic Nodal activity, revealing a new paradigm in the regulation of Nodal signaling, which is likely to be conserved. DOI: http://dx.doi.org/10.7554/eLife.00683.001 PMID:24040511

  18. Cracking the nodule worm code advances knowledge of parasite biology and biotechnology to tackle major diseases of livestock.

    PubMed

    Tyagi, Rahul; Joachim, Anja; Ruttkowski, Bärbel; Rosa, Bruce A; Martin, John C; Hallsworth-Pepin, Kymberlie; Zhang, Xu; Ozersky, Philip; Wilson, Richard K; Ranganathan, Shoba; Sternberg, Paul W; Gasser, Robin B; Mitreva, Makedonka

    2015-11-01

    Many infectious diseases caused by eukaryotic pathogens have a devastating, long-term impact on animal health and welfare. Hundreds of millions of animals are affected by parasitic nematodes of the order Strongylida. Unlocking the molecular biology of representatives of this order, and understanding nematode-host interactions, drug resistance and disease using advanced technologies could lead to entirely new ways of controlling the diseases that they cause. Oesophagostomum dentatum (nodule worm; superfamily Strongyloidea) is an economically important strongylid nematode parasite of swine worldwide. The present article reports recent advances made in biology and animal biotechnology through the draft genome and developmental transcriptome of O. dentatum, in order to support biological research of this and related parasitic nematodes as well as the search for new and improved interventions. This first genome of any member of the Strongyloidea is 443 Mb in size and predicted to encode 25,291 protein-coding genes. Here, we review the dynamics of transcription throughout the life cycle of O. dentatum, describe double-stranded RNA interference (RNAi) machinery and infer molecules involved in development and reproduction, and in inducing or modulating immune responses or disease. The secretome predicted for O. dentatum is particularly rich in peptidases linked to interactions with host tissues and/or feeding activity, and a diverse array of molecules likely involved in immune responses. This research progress provides an important resource for future comparative genomic and molecular biological investigations as well as for biotechnological research toward new anthelmintics, vaccines and diagnostic tests.

  19. Improved NASA-ANOPP Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Kontos, K. B.; Janardan, B. A.; Gliebe, P. R.

    1996-01-01

    Recent experience using ANOPP to predict turbofan engine flyover noise suggests that it over-predicts overall EPNL by a significant amount. An improvement in this prediction method is desired for system optimization and assessment studies of advanced UHB engines. An assessment of the ANOPP fan inlet, fan exhaust, jet, combustor, and turbine noise prediction methods is made using static engine component noise data from the CF6-8OC2, E(3), and QCSEE turbofan engines. It is shown that the ANOPP prediction results are generally higher than the measured GE data, and that the inlet noise prediction method (Heidmann method) is the most significant source of this overprediction. Fan noise spectral comparisons show that improvements to the fan tone, broadband, and combination tone noise models are required to yield results that more closely simulate the GE data. Suggested changes that yield improved fan noise predictions but preserve the Heidmann model structure are identified and described. These changes are based on the sets of engine data mentioned, as well as some CFM56 engine data that was used to expand the combination tone noise database. It should be noted that the recommended changes are based on an analysis of engines that are limited to single stage fans with design tip relative Mach numbers greater than one.

  20. Error estimation and adaptive order nodal method for solving multidimensional transport problems

    SciTech Connect

    Zamonsky, O.M.; Gho, C.J.; Azmy, Y.Y.

    1998-01-01

    The authors propose a modification of the Arbitrarily High Order Transport Nodal method whereby they solve each node and each direction using different expansion order. With this feature and a previously proposed a posteriori error estimator they develop an adaptive order scheme to automatically improve the accuracy of the solution of the transport equation. They implemented the modified nodal method, the error estimator and the adaptive order scheme into a discrete-ordinates code for solving monoenergetic, fixed source, isotropic scattering problems in two-dimensional Cartesian geometry. They solve two test problems with large homogeneous regions to test the adaptive order scheme. The results show that using the adaptive process the storage requirements are reduced while preserving the accuracy of the results.

  1. Error analysis of the quadratic nodal expansion method in slab geometry

    SciTech Connect

    Penland, R.C.; Turinsky, P.J.; Azmy, Y.Y.

    1994-10-01

    As part of an effort to develop an adaptive mesh refinement strategy for use in state-of-the-art nodal diffusion codes, the authors derive error bounds on the solution variables of the quadratic Nodal Expansion Method (NEM) in slab geometry. Closure of the system is obtained through flux discontinuity relationships and boundary conditions. In order to verify the analysis presented, the authors compare the quadratic NEM to the analytic solution of a test problem. The test problem for this investigation is a one-dimensional slab [0,20cm] with L{sup 2} = 6.495cm{sup 2} and D = 0.1429cm. The slab has a unit neutron source distributed uniformly throughout and zero flux boundary conditions. The analytic solution to this problem is used to compute the node-average fluxes over a variety of meshes, and these are used to compute the NEM maximum error on each mesh.

  2. A Hybrid Nodal Method for Time-Dependent Incompressible Flow in Two-Dimensional Arbitrary Geometries

    SciTech Connect

    Toreja, A J; Uddin, R

    2002-10-21

    A hybrid nodal-integral/finite-analytic method (NI-FAM) is developed for time-dependent, incompressible flow in two-dimensional arbitrary geometries. In this hybrid approach, the computational domain is divided into parallelepiped and wedge-shaped space-time nodes (cells). The conventional nodal integral method (NIM) is applied to the interfaces between adjacent parallelepiped nodes (cells), while a finite analytic approach is applied to the interfaces between parallelepiped and wedge-shaped nodes (cells). In this paper, the hybrid method is formally developed and an application of the NI-FAM to fluid flow in an enclosed cavity is presented. Results are compared with those obtained using a commercial computational fluid dynamics code.

  3. Anomalous thermodynamic power laws in nodal superconductors

    NASA Astrophysics Data System (ADS)

    Quintanilla, Jorge; Mazidian, Bayan; Annett, James F.; Hillier, Adrian D.

    2013-03-01

    Unconventional superconductors are frequently identified by the observation of power law behaviour on low temperature thermodynamic properties such as specific heat. These power laws generally derive from the linear spectrum near points or lines of zeros, or nodes, in the superconducting energy gap on the Fermi surface. Here we show that, in addition to the usual point and line nodes, a much wider class of different nodal types can occur. Some of these new types of nodes typically occur when there are transitions between different types of gap node topology, for example when point or line nodes first appear as a function of some physical parameter. We derive anomalous, non-integer thermodynamic power laws associated with these new nodal types and predict their occurrence in iron pnictide superconductors and in the noncentrosymmetric system Li2Pd3-xPtxB. This works was supported by EPSRC and STFC (U.K.) J.Q. gratefully acknowledges funding from HEFCE and STFC through the South-East Physics network (SEPnet).

  4. MHD Simulation of Magnetic Nozzle Plasma with the NIMROD Code: Applications to the VASIMR Advanced Space Propulsion Concept

    NASA Astrophysics Data System (ADS)

    Tarditi, Alfonso G.; Shebalin, John V.

    2002-11-01

    A simulation study with the NIMROD code [1] is being carried on to investigate the efficiency of the thrust generation process and the properties of the plasma detachment in a magnetic nozzle. In the simulation, hot plasma is injected in the magnetic nozzle, modeled as a 2D, axi-symmetric domain. NIMROD has two-fluid, 3D capabilities but the present runs are being conducted within the MHD, 2D approximation. As the plasma travels through the magnetic field, part of its thermal energy is converted into longitudinal kinetic energy, along the axis of the nozzle. The plasma eventually detaches from the magnetic field at a certain distance from the nozzle throat where the kinetic energy becomes larger than the magnetic energy. Preliminary NIMROD 2D runs have been benchmarked with a particle trajectory code showing satisfactory results [2]. Further testing is here reported with the emphasis on the analysis of the diffusion rate across the field lines and of the overall nozzle efficiency. These simulation runs are specifically designed for obtaining comparisons with laboratory measurements of the VASIMR experiment, by looking at the evolution of the radial plasma density and temperature profiles in the nozzle. VASIMR (Variable Specific Impulse Magnetoplasma Rocket, [3]) is an advanced space propulsion concept currently under experimental development at the Advanced Space Propulsion Laboratory, NASA Johnson Space Center. A plasma (typically ionized Hydrogen or Helium) is generated by a RF (Helicon) discharge and heated by an Ion Cyclotron Resonance Heating antenna. The heated plasma is then guided into a magnetic nozzle to convert the thermal plasma energy into effective thrust. The VASIMR system has no electrodes and a solenoidal magnetic field produced by an asymmetric mirror configuration ensures magnetic insulation of the plasma from the material surfaces. By powering the plasma source and the heating antenna at different levels it is possible to vary smoothly of the

  5. The correction of pebble bed reactor nodal cross sections for the effects of leakage and depletion history

    NASA Astrophysics Data System (ADS)

    Hudson, Nathanael Harrison

    An accurate and computationally fast method to generate nodal cross sections for the Pebble Bed Reactor (PBR) was presented. In this method, named Spectral History Correction (SHC), a set of fine group microscopic cross section libraries, pre-computed at specified depletion and moderation states, was coupled with the nodal nuclide densities and group bucklings to compute the new fine group spectrum for each node. The relevant fine group cross-section library was then recollapsed to the local broad group cross-section structure with this new fine group spectrum. This library set was tracked in terms of fuel isotopic densities. Fine group modulation factors (to correct the homogeneous flux for heterogeneous effects) and fission spectra were also stored with the cross section library. As the PBR simulation converges to a steady state fuel cycle, the initial nodal cross section library becomes inaccurate due to the burnup of the fuel and the neutron leakage into and out of the node. Because of the recirculation of discharged fuel pebbles with fresh fuel pebbles, a node can consist of a collection of pebbles at various burnup stages. To account for the nodal burnup, the microscopic cross sections were combined with nodal averaged atom densities to approximate the fine group macroscopic cross-sections for that node. These constructed, homogeneous macroscopic cross sections within the node were used to calculate a numerical solution for the fine group spectrum with B1 theory. This new fine spectrum was used to collapse the pre-computed microscopic cross section library to the broad group structure employed by the fuel cycle code. This SHC technique was developed and practically implemented as a subroutine within the PBR fuel cycle code PEBBED. The SHC subroutine was called to recalculate the broad group cross sections during the code convergence. The result was a fast method that compared favorably to the benchmark scheme of cross section calculation with the lattice

  6. Topological surface states in nodal superconductors.

    PubMed

    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. PMID:26000466

  7. 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.

  8. Fast subpel motion estimation for H.264/advanced video coding with an adaptive motion vector accuracy decision

    NASA Astrophysics Data System (ADS)

    Lee, Hoyoung; Jung, Bongsoo; Jung, Jooyoung; Jeon, Byeungwoo

    2012-11-01

    The quarter-pel motion vector accuracy supported by H.264/advanced video coding (AVC) in motion estimation (ME) and compensation (MC) provides high compression efficiency. However, it also increases the computational complexity. While various well-known fast integer-pel ME methods are already available, lack of a good, fast subpel ME method results in problems associated with relatively high computational complexity. This paper presents one way of solving the complexity problem of subpel ME by making adaptive motion vector (MV) accuracy decisions in inter-mode selection. The proposed MV accuracy decision is made using inter-mode selection of a macroblock with two decision criteria. Pixels are classified as stationary (and/or homogeneous) or nonstationary (and/or nonhomogeneous). In order to avoid unnecessary interpolation and processing, a proper subpel ME level is chosen among four different combinations, each of which has a different MV accuracy and number of subpel ME iterations based on the classification. Simulation results using an open source x264 software encoder show that without any noticeable degradation (by -0.07 dB on average), the proposed method reduces total encoding time and subpel ME time, respectively, by 51.78% and by 76.49% on average, as compared to the conventional full-pel pixel search.

  9. Fast multiple run_before decoding method for efficient implementation of an H.264/advanced video coding context-adaptive variable length coding decoder

    NASA Astrophysics Data System (ADS)

    Ki, Dae Wook; Kim, Jae Ho

    2013-07-01

    We propose a fast new multiple run_before decoding method in context-adaptive variable length coding (CAVLC). The transform coefficients are coded using CAVLC, in which the run_before symbols are generated for a 4×4 block input. To speed up the CAVLC decoding, the run_before symbols need to be decoded in parallel. We implemented a new CAVLC table for simultaneous decoding of up to three run_befores. The simulation results show a Total Speed-up Factor of 205%˜144% over various resolutions and quantization steps.

  10. Tunable Weyl Points in Periodically Driven Nodal Line Semimetals.

    PubMed

    Yan, Zhongbo; Wang, Zhong

    2016-08-19

    Weyl semimetals and nodal line semimetals are characterized by linear band touching at zero-dimensional points and one-dimensional lines, respectively. We predict that a circularly polarized light drives nodal line semimetals into Weyl semimetals. The Floquet Weyl points thus obtained are tunable by the incident light, which enables investigations of them in a highly controllable manner. The transition from nodal line semimetals to Weyl semimetals is accompanied by the emergence of a large and tunable anomalous Hall conductivity. Our predictions are experimentally testable by transport measurement in film samples or by pump-probe angle-resolved photoemission spectroscopy. PMID:27588882

  11. NODAL — The second life of the accelerator control language

    NASA Astrophysics Data System (ADS)

    Cuisinier, G.; Perriollat, F.; Ribeiro, P.; Kagarmanov, A.; Kovaltsov, V.

    1994-12-01

    NODAL has been a popular interpreter language for accelerator controls since the beginning of the 1970s. NODAL has been rewritten in the C language to be easily portable to the different computer platforms which are in use in accelerator controls. The paper describes the major features of this new version of NODAL, the major software packages which are available through this implementation, the platforms on which it is currently running, and some relevant performances. The experience gained during the rejuvenation project of the CERN accelerator control systems is presented. The benefit of this is discussed, in particular in a view of the prevailing strong constraints in personnel and money resources.

  12. Tunable Weyl Points in Periodically Driven Nodal Line Semimetals

    NASA Astrophysics Data System (ADS)

    Yan, Zhongbo; Wang, Zhong

    2016-08-01

    Weyl semimetals and nodal line semimetals are characterized by linear band touching at zero-dimensional points and one-dimensional lines, respectively. We predict that a circularly polarized light drives nodal line semimetals into Weyl semimetals. The Floquet Weyl points thus obtained are tunable by the incident light, which enables investigations of them in a highly controllable manner. The transition from nodal line semimetals to Weyl semimetals is accompanied by the emergence of a large and tunable anomalous Hall conductivity. Our predictions are experimentally testable by transport measurement in film samples or by pump-probe angle-resolved photoemission spectroscopy.

  13. Reflector modelling of small high leakage cores making use of multi-group nodal equivalence theory

    SciTech Connect

    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)

  14. Designer Nodal/BMP2 Chimeras Mimic Nodal Signaling, Promote Chondrogenesis, and Reveal a BMP2-like Structure

    PubMed Central

    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

  15. Challenge problem and milestones for : Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC).

    SciTech Connect

    Freeze, Geoffrey A.; Wang, Yifeng; Howard, Robert; McNeish, Jerry A.; Schultz, Peter Andrew; Arguello, Jose Guadalupe, Jr.

    2010-09-01

    This report describes the specification of a challenge problem and associated challenge milestones for the Waste Integrated Performance and Safety Codes (IPSC) supporting the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The NEAMS challenge problems are designed to demonstrate proof of concept and progress towards IPSC goals. The goal of the Waste IPSC is to develop an integrated suite of modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. To demonstrate proof of concept and progress towards these goals and requirements, a Waste IPSC challenge problem is specified that includes coupled thermal-hydrologic-chemical-mechanical (THCM) processes that describe (1) the degradation of a borosilicate glass waste form and the corresponding mobilization of radionuclides (i.e., the processes that produce the radionuclide source term), (2) the associated near-field physical and chemical environment for waste emplacement within a salt formation, and (3) radionuclide transport in the near field (i.e., through the engineered components - waste form, waste package, and backfill - and the immediately adjacent salt). The initial details of a set of challenge milestones that collectively comprise the full challenge problem are also specified.

  16. Numerical divergence effects of equivalence theory in the nodal expansion method

    SciTech Connect

    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.

  17. The genetics of nodal marginal zone lymphoma.

    PubMed

    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

    2016-09-01

    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.

  18. The genetics of nodal marginal zone lymphoma

    PubMed Central

    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

  19. The genetics of nodal marginal zone lymphoma.

    PubMed

    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

    2016-09-01

    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

  20. 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.

  1. Classification, Electrophysiological Features and Therapy of Atrioventricular Nodal Reentrant Tachycardia

    PubMed Central

    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

  2. Classification, Electrophysiological Features and Therapy of Atrioventricular Nodal Reentrant Tachycardia

    PubMed Central

    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.

  3. Bilinear nodal transport method in weighted diamond difference form

    SciTech Connect

    Azmy, Y.Y.

    1987-01-01

    Nodal methods have been developed and implemented for the numerical solution of the discrete ordinates neutron transport equation. Numerical testing of these methods and comparison of their results to those obtained by conventional methods have established the high accuracy of nodal methods. Furthermore, it has been suggested that the linear-linear approximation is the most computationally efficient, practical nodal approximation. Indeed, this claim has been substantiated by comparing the accuracy in the solution, and the CPU time required to achieve convergence to that solution by several nodal approximations, as well as the diamond difference scheme. Two types of linear-linear nodal methods have been developed in the literature: analytic linear-linear (NLL) methods, in which the transverse-leakage terms are derived analytically, and approximate linear-linear (PLL) methods, in which these terms are approximated. In spite of their higher accuracy, NLL methods result in very complicated discrete-variable equations that exhibit a high degree of coupling, thus requiring special solution algorithms. On the other hand, the sacrificed accuracy in PLL methods is compensated for by the simple discrete-variable equations and diamond-difference-like solution algorithm. In this paper the authors outline the development of an NLL nodal method, the bilinear method, which can be written in a weighted diamond difference form with one spatial weight per dimension that is analytically derived rather than preassigned in an ad hoc fashion.

  4. An upwind nodal integral method for incompressible fluid flow

    SciTech Connect

    Esser, P.D. ); Witt, R.J. )

    1993-05-01

    An upwind nodal solution method is developed for the steady, two-dimensional flow of an incompressible fluid. The formulation is based on the nodal integral method, which uses transverse integrations, analytical solutions of the one-dimensional averaged equations, and node-averaged uniqueness constraints to derive the discretized nodal equations. The derivation introduces an exponential upwind bias by retaining the streamwise convection term in the homogeneous part of the transverse-integrated convection-diffusion equation. The method is adapted to the stream function-vorticity form of the Navier-Stokes equations, which are solved over a nonstaggered nodal mesh. A special nodal scheme is used for the Poisson stream function equation to properly account for the exponentially varying vorticity source. Rigorous expressions for the velocity components and the no-slip vorticity boundary condition are derived from the stream function formulation. The method is validated with several benchmark problems. An idealized purely convective flow of a scalar step function indicates that the nodal approximation errors are primarily dispersive, not dissipative, in nature. Results for idealized and actual recirculating driven-cavity flows reveal a significant reduction in false diffusion compared with conventional finite difference techniques.

  5. Comparison of the 3-D Deterministic Neutron Transport Code Attila® To Measure Data, MCNP And MCNPX For The Advanced Test Reactor

    SciTech Connect

    D. Scott Lucas; D. S. Lucas

    2005-09-01

    An LDRD (Laboratory Directed Research and Development) project is underway at the Idaho National Laboratory (INL) to apply the three-dimensional multi-group deterministic neutron transport code (Attila®) to criticality, flux and depletion calculations of the Advanced Test Reactor (ATR). This paper discusses the development of Attila models for ATR, capabilities of Attila, the generation and use of different cross-section libraries, and comparisons to ATR data, MCNP, MCNPX and future applications.

  6. Comparison of the PLTEMP code flow instability predictions with measurements made with electrically heated channels for the advanced test reactor.

    SciTech Connect

    Feldman, E.

    2011-06-09

    When the University of Missouri Research Reactor (MURR) was designed in the 1960s the potential for fuel element burnout by a phenomenon referred to at that time as 'autocatalytic vapor binding' was of serious concern. This type of burnout was observed to occur at power levels considerably lower than those that were known to cause critical heat flux. The conversion of the MURR from HEU fuel to LEU fuel will probably require significant design changes, such as changes in coolant channel thicknesses, that could affect the thermal-hydraulic behavior of the reactor core. Therefore, the redesign of the MURR to accommodate an LEU core must address the same issues of fuel element burnout that were of concern in the 1960s. The Advanced Test Reactor (ATR) was designed at about the same time as the MURR and had similar concerns with regard to fuel element burnout. These concerns were addressed in the ATR by two groups of thermal-hydraulic tests that employed electrically heated simulated fuel channels. The Croft (1964), Reference 1, tests were performed at ANL. The Waters (1966), Reference 2, tests were performed at Hanford Laboratories in Richland Washington. Since fuel element surface temperatures rise rapidly as burnout conditions are approached, channel surface temperatures were carefully monitored in these experiments. For self-protection, the experimental facilities were designed to cut off the electric power when rapidly increasing surface temperatures were detected. In both the ATR reactor and in the tests with electrically heated channels, the heated length of the fuel plate was 48 inches, which is about twice that of the MURR. Whittle and Forgan (1967) independently conducted tests with electrically heated rectangular channels that were similar to the tests by Croft and by Walters. In the Whittle and Forgan tests the heated length of the channel varied among the tests and was between 16 and 24 inches. Both Waters and Whittle and Forgan show that the cause of the

  7. Advanced GF(32) nonbinary LDPC coded modulation with non-uniform 9-QAM outperforming star 8-QAM.

    PubMed

    Liu, Tao; Lin, Changyu; Djordjevic, Ivan B

    2016-06-27

    In this paper, we first describe a 9-symbol non-uniform signaling scheme based on Huffman code, in which different symbols are transmitted with different probabilities. By using the Huffman procedure, prefix code is designed to approach the optimal performance. Then, we introduce an algorithm to determine the optimal signal constellation sets for our proposed non-uniform scheme with the criterion of maximizing constellation figure of merit (CFM). The proposed nonuniform polarization multiplexed signaling 9-QAM scheme has the same spectral efficiency as the conventional 8-QAM. Additionally, we propose a specially designed GF(32) nonbinary quasi-cyclic LDPC code for the coded modulation system based on the 9-QAM non-uniform scheme. Further, we study the efficiency of our proposed non-uniform 9-QAM, combined with nonbinary LDPC coding, and demonstrate by Monte Carlo simulation that the proposed GF(23) nonbinary LDPC coded 9-QAM scheme outperforms nonbinary LDPC coded uniform 8-QAM by at least 0.8dB.

  8. Advanced GF(32) nonbinary LDPC coded modulation with non-uniform 9-QAM outperforming star 8-QAM.

    PubMed

    Liu, Tao; Lin, Changyu; Djordjevic, Ivan B

    2016-06-27

    In this paper, we first describe a 9-symbol non-uniform signaling scheme based on Huffman code, in which different symbols are transmitted with different probabilities. By using the Huffman procedure, prefix code is designed to approach the optimal performance. Then, we introduce an algorithm to determine the optimal signal constellation sets for our proposed non-uniform scheme with the criterion of maximizing constellation figure of merit (CFM). The proposed nonuniform polarization multiplexed signaling 9-QAM scheme has the same spectral efficiency as the conventional 8-QAM. Additionally, we propose a specially designed GF(32) nonbinary quasi-cyclic LDPC code for the coded modulation system based on the 9-QAM non-uniform scheme. Further, we study the efficiency of our proposed non-uniform 9-QAM, combined with nonbinary LDPC coding, and demonstrate by Monte Carlo simulation that the proposed GF(23) nonbinary LDPC coded 9-QAM scheme outperforms nonbinary LDPC coded uniform 8-QAM by at least 0.8dB. PMID:27410549

  9. Memory-efficient table look-up optimized algorithm for context-based adaptive variable length decoding in H.264/advanced video coding

    NASA Astrophysics Data System (ADS)

    Wang, Jianhua; Cheng, Lianglun; Wang, Tao; Peng, Xiaodong

    2016-03-01

    Table look-up operation plays a very important role during the decoding processing of context-based adaptive variable length decoding (CAVLD) in H.264/advanced video coding (AVC). However, frequent table look-up operation can result in big table memory access, and then lead to high table power consumption. Aiming to solve the problem of big table memory access of current methods, and then reduce high power consumption, a memory-efficient table look-up optimized algorithm is presented for CAVLD. The contribution of this paper lies that index search technology is introduced to reduce big memory access for table look-up, and then reduce high table power consumption. Specifically, in our schemes, we use index search technology to reduce memory access by reducing the searching and matching operations for code_word on the basis of taking advantage of the internal relationship among length of zero in code_prefix, value of code_suffix and code_lengh, thus saving the power consumption of table look-up. The experimental results show that our proposed table look-up algorithm based on index search can lower about 60% memory access consumption compared with table look-up by sequential search scheme, and then save much power consumption for CAVLD in H.264/AVC.

  10. Pelvic Nodal Radiotherapy in Patients With Unfavorable Intermediate and High-Risk Prostate Cancer: Evidence, Rationale, and Future Directions

    SciTech Connect

    Morikawa, Lisa K.; Roach, Mack

    2011-05-01

    Over the past 15 years, there have been three major advances in the use of external beam radiotherapy in the management of men with clinically localized prostate made. They include: (1) image guided (IG) three-dimensional conformal/intensity modulated radiotherapy; (2) radiation dose escalation; and (3) androgen deprivation therapy. To date only the last of these three advances have been shown to improve overall survival. The presence of occult pelvic nodal involvement could explain the failure of increased conformality and dose escalation to prolong survival, because the men who appear to be at the greatest risk of death from clinically localized prostate cancer are those who are likely to have lymph node metastases. This review discusses the evidence for prophylactic pelvic nodal radiotherapy, including the key trials and controversies surrounding this issue.

  11. Expression of Nodal and Nodal Receptors in Prostate Stem Cells and Prostate Cancer Cells: Autocrine Effects on Cell Proliferation and Migration

    PubMed Central

    Vo, BaoHan T.; Khan, Shafiq A.

    2010-01-01

    BACKGROUND Nodal, a TGFβ like growth factor, functions as an embryonic morphogen that maintains the pluripotency of embryonic stem cells. Nodal has been implicated in cancer progression; however, there is no information on expression and functions of Nodal in prostate cancer. In this study, we have investigated the expression of Nodal, its receptors, and its effects on proliferation and migration of human prostate cells. METHODS RT-PCR, qPCR, and Western blot analyses were performed to analyze expression of Nodal and Nodal receptors and its effects on phosphorylation of Smad2/3 in prostate cells. The effects on proliferation and migration were determined by 3H-Thymidine incorporation and cell migration assays in the presence or absence of Nodal receptor inhibitor (SB431542). RESULTS Nodal was highly expressed in WPE, DU145, LNCaP, and LNCaP-C81 cells with low expression in RWPE1 and RWPE2 cells, but not in PREC, PC3 and PC3M cells. Nodal receptors are expressed at varying levels in all prostate cells. Treatment with exogenous Nodal induced phosphorylation of Smad2/3 in WPE, DU145, and PC3 cells, which was blocked by SB431542. Nodal dose-dependently inhibited proliferation of WPE, RWPE1 and DU145 cells, but not LNCaP and PC3 cells. Nodal induced cell migration in PC3 cells, which was inhibited by SB431542; Nodal had no effect on cell migration in WPE and DU145 cells. The effects of Nodal on cell proliferation and migration are mediated via ALK4 and ActRII/ActRIIB receptors and Smad 2/3 phosphorylation. CONCLUSIONS Nodal may function as an autocrine regulator of proliferation and migration of prostate cancer cells. PMID:21557273

  12. Experimental and Thermalhydraulic Code Assessment of the Transient Behavior of the Passive Condenser System in an Advanced Boiling Water Reactor

    SciTech Connect

    S.T. Revankar; W. Zhou; Gavin Henderson

    2008-07-08

    The main goal of the project was to study analytically and experimentally the condensation heat transfer for the passive condenser system such as GE Economic Simplified Boiling Water Reactor (ESBWR). The effect of noncondensable gas in condenser tube and the reduction of secondary pool water level to the condensation heat transfer coefficient was the main focus in this research. The objectives of this research were to : 1) obtain experimental data on the local and tube averaged condensation heat transfer rates for the PCCS with non-condensable and with change in the secondary pool water, 2) assess the RELAP5 and TRACE computer code against the experimental data, and 3) develop mathematical model and ehat transfer correlation for the condensation phenomena for system code application. The project involves experimentation, theoretical model development and verification, and thermal- hydraulic codes assessment.

  13. Diffusion-Weighted MRI for Nodal Staging of Head and Neck Squamous Cell Carcinoma: Impact on Radiotherapy Planning

    SciTech Connect

    Dirix, Piet; Vandecaveye, Vincent; De Keyzer, Frederik; Op de beeck, Katya; Poorten, Vincent Vander; Delaere, Pierre; Verbeken, Eric; Hermans, Robert; Nuyts, Sandra

    2010-03-01

    Purpose: To evaluate the use of diffusion-weighted magnetic resonance imaging (DW-MRI) for nodal staging and its impact on radiotherapy (RT) planning. Methods and Materials: Twenty-two patients with locally advanced head and neck squamous cell carcinoma underwent contrast-enhanced computed tomography (CT), as well as MRI (with routine and DW sequences) prior to neck dissection. After topographic correlation, lymph nodes were evaluated microscopically with prekeratin immunostaining. Pathology results were correlated with imaging findings and an RT planning study was performed for these surgically treated patients. One set of target volumes was based on conventional imaging only, and another set was based on the corresponding DW-MRI images. A third reference set was contoured based solely on pathology results. Results: A sensitivity of 89% and a specificity of 97% per lymph node were found for DW-MRI. Nodal staging agreement between imaging and pathology was significantly stronger for DW-MRI (kappa = 0.97; 95% confidence interval [CI], 0.84-1.00) than for conventional imaging (kappa = 0.56; 95% CI, 0.16-0.96; p = 0.019, by McNemar's test). For both imaging modalities, the absolute differences between RT volumes and those obtained by pathology were calculated. Using an exact paired Wilcoxon test, the observed difference was significantly larger for conventional imaging than for DW-MRI for nodal gross tumor volume (p = 0.0013), as well as for nodal clinical target volume (p = 0.0415) delineation. Conclusions: These results suggest that DW-MRI is superior to conventional imaging for preradiotherapy nodal staging of head and neck squamous cell carcinoma, and provides a potential impact on organsparing and tumor control.

  14. On the Nodal Lines of Eisenstein Series on Schottky Surfaces

    NASA Astrophysics Data System (ADS)

    Jakobson, Dmitry; Naud, Frédéric

    2016-09-01

    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.

  15. Simulating Weyl points and nodal loops in an optical superlattice

    NASA Astrophysics Data System (ADS)

    Zhang, Dan-Wei

    2016-08-01

    We propose a scheme to simulate Weyl points and nodal loops with ultracold atoms in an optical lattice that is subjected to realizable synthetic magnetic field and synthetic dimension. We show that a Hofstadter-like Hamiltonian with a cyclically parameterized on-site energy term can be realized in a tunable two-dimensional optical superlattice, based on the laser-assisted atomic tunneling method. This model effectively describes a three-dimensional periodic lattice system under magnetic fluxes, where a synthetic dimension is encoded by a cyclical phase of the optical lattice potential. For different atomic hopping configurations, the single-particle bands are demonstrated to, respectively, exhibit Weyl points and nodal loops in the extended three-dimensional Brillouin zone. Furthermore, we illustrate that the mimicked Weyl points and nodal loops can be experimentally detected by measuring the atomic transfer fraction in Bloch-Zener oscillations.

  16. A computational study of nodal-based tetrahedral element behavior.

    SciTech Connect

    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.

  17. Deformation modes in the finite element absolute nodal coordinate formulation

    NASA Astrophysics Data System (ADS)

    Sugiyama, Hiroyuki; Gerstmayr, Johannes; Shabana, Ahmed A.

    2006-12-01

    The objective of this study is to provide interpretation of the deformation modes in the finite element absolute nodal coordinate formulation using several strain definitions. In this finite element formulation, the nodal coordinates consist of absolute position coordinates and gradients that can be used to define a unique rotation and deformation fields within the element as well as at the nodal points. The results obtained in this study clearly show cross-section deformation modes eliminated when the number of the finite element nodal coordinates is systematically and consistently reduced. Using the procedure discussed in this paper one can obtain a reduced order dynamic model, eliminate position vector gradients that introduce high frequencies to the solution of some problems, achieve the continuity of the remaining gradients at the nodal points, and obtain a formulation that automatically satisfies the principle of work and energy. Furthermore, the resulting dynamic model, unlike large rotation finite element formulations, leads to a unique rotation field, and as a consequence, the obtained formulation does not suffer from the problem of coordinate redundancy that characterizes existing large deformation finite element formulations. In order to accurately define strain components that can have easy physical interpretation, a material coordinate system is introduced to define the material element rotation and deformation. Using the material coordinate system, the Timoshenko-Reissner and Euler -Bernoulli beam models can be systematically obtained as special cases of the absolute nodal coordinate formulation beam models. While a constraint approach is used in this study to eliminate the cross-section deformation modes, it is important to point out as mentioned in this paper that lower-order finite elements, some of which already presented in previous investigations, can be efficiently used in thin and stiff structure applications.

  18. A transient, quadratic nodal method for triangular-Z geometry

    SciTech Connect

    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.

  19. 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.

  20. 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.

  1. Advanced Technology Airfoil Research, volume 1, part 1. [conference on development of computational codes and test facilities

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A comprehensive review of all NASA airfoil research, conducted both in-house and under grant and contract, as well as a broad spectrum of airfoil research outside of NASA is presented. Emphasis is placed on the development of computational aerodynamic codes for airfoil analysis and design, the development of experimental facilities and test techniques, and all types of airfoil applications.

  2. Electromagnetic self-consistent field initialization and fluid advance techniques for hybrid-kinetic PWFA code Architect

    NASA Astrophysics Data System (ADS)

    Massimo, F.; Marocchino, A.; Rossi, A. R.

    2016-09-01

    The realization of Plasma Wakefield Acceleration experiments with high quality of the accelerated bunches requires an increasing number of numerical simulations to perform first-order assessments for the experimental design and online-analysis of the experimental results. Particle in Cell codes are the state-of-the-art tools to study the beam-plasma interaction mechanism, but due to their requirements in terms of number of cores and computational time makes them unsuitable for quick parametric scans. Considerable interest has been shown thus in methods which reduce the computational time needed for the simulation of plasma acceleration. Such methods include the use of hybrid kinetic-fluid models, which treat the relativistic bunches as in a PIC code and the background plasma electrons as a fluid. A technique to properly initialize the bunch electromagnetic fields in the time explicit hybrid kinetic-fluid code Architect is presented, as well the implementation of the Flux Corrected Transport scheme for the fluid equations integrated in the code.

  3. Generation of SFR few-group constants using the Monte Carlo code Serpent

    SciTech Connect

    Fridman, E.; Rachamin, R.; Shwageraus, E.

    2013-07-01

    In this study, the Serpent Monte Carlo code was used as a tool for preparation of homogenized few-group cross sections for the nodal diffusion analysis of Sodium cooled Fast Reactor (SFR) cores. Few-group constants for two reference SFR cores were generated by Serpent and then employed by nodal diffusion code DYN3D in 2D full core calculations. The DYN3D results were verified against the references full core Serpent Monte Carlo solutions. A good agreement between the reference Monte Carlo and nodal diffusion results was observed demonstrating the feasibility of using Serpent for generation of few-group constants for the deterministic SFR analysis. (authors)

  4. Oyster Creek cycle 10 nodal model parameter optimization study using PSMS

    SciTech Connect

    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.

  5. Hybrid modal nodal method for multibody smart structure model reduction: application to modal feedback control

    NASA Astrophysics Data System (ADS)

    Matichard, Fabrice; Gaudiller, Luc

    2006-12-01

    The hybrid modal nodal (HMN) method, designed for multibody smart structure model reduction and feedback control development, is based on the independent modeling of structural and electromechanical behavior. Firstly, this approach permits reducing the model of substructures independently of the electromechanical behavior. This allows choosing the most adapted component mode synthesis (CMS) method and corresponding code for any application, something that is not permitted by classical multi-physics projection-based methods. Thus, the substructuring process used in this paper is based on super-elements directly adapted for multibody dynamics modeling. Secondly, the electromechanical behavior of distributed components is introduced into the structural modal model via a nodal formulation. Its independence of any projection guarantees accuracy and its formulation is valid whatever the multibody assembly and its modal shapes. The proposed application is composed of successive developments and experiments designed to validate the model reduction method, its implementation and its use for modal feedback control, i.e. a smart beam, actively controlled by piezoelectric ceramics. It is successively clamped to illustrate the electromechanical coupling reduction, articulated to introduce the rigid-body/flexible mode coupling reduction and, finally, bi-articulated in order to deal with the nonlinear problem.

  6. Application of advanced computational procedures for modeling solar-wind interactions with Venus: Theory and computer code

    NASA Technical Reports Server (NTRS)

    Stahara, S. S.; Klenke, D.; Trudinger, B. C.; Spreiter, J. R.

    1980-01-01

    Computational procedures are developed and applied to the prediction of solar wind interaction with nonmagnetic terrestrial planet atmospheres, with particular emphasis to Venus. The theoretical method is based on a single fluid, steady, dissipationless, magnetohydrodynamic continuum model, and is appropriate for the calculation of axisymmetric, supersonic, super-Alfvenic solar wind flow past terrestrial planets. The procedures, which consist of finite difference codes to determine the gasdynamic properties and a variety of special purpose codes to determine the frozen magnetic field, streamlines, contours, plots, etc. of the flow, are organized into one computational program. Theoretical results based upon these procedures are reported for a wide variety of solar wind conditions and ionopause obstacle shapes. Plasma and magnetic field comparisons in the ionosheath are also provided with actual spacecraft data obtained by the Pioneer Venus Orbiter.

  7. 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…

  8. PoroTomo Subtask 6.3 Nodal Seismometers Metadata

    DOE Data Explorer

    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.

  9. Nodal-mediated epigenesis requires dynamin-mediated endocytosis

    PubMed Central

    Ertl, Robin P.; Robertson, Anthony J.; Saunders, Diane; Coffman, James A.

    2011-01-01

    Nodal proteins are diffusible morphogens that drive pattern formation via short-range feedback activation coupled to long-range Lefty-mediated inhibition. In the sea urchin embryo, specification of the secondary (oral-aboral) axis occurs via zygotic expression of nodal, which is localized to the prospective oral ectoderm at early blastula stage. In mid-blastula stage embryos treated with low micromolar nickel or zinc, nodal expression expands progressively beyond the confines of this localized domain to encompass the entire equatorial circumference of the embryo, producing radialized embryos lacking an oral-aboral axis. RNAseq analysis of embryos treated with nickel, zinc or cadmium (which does not radialize embryos) showed that several genes involved in endocytosis were similarly perturbed by nickel and zinc but not cadmium. Inhibiting dynamin, a GTPase required for receptor-mediated endocytosis, phenocopies the effects of nickel and zinc, suggesting that dynamin-mediated endocytosis is required as a sink to limit the range of Nodal signaling. PMID:21337468

  10. 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...

  11. Wave pinning and spatial patterning in a mathematical model of Antivin/Lefty-Nodal signalling.

    PubMed

    Middleton, A M; King, J R; Loose, M

    2013-12-01

    Nodal signals are key regulators of mesoderm and endoderm development in vertebrate embryos. It has been observed experimentally that in Xenopus embryos the spatial range of Nodal signals is restricted by the signal Antivin (also known as Lefty). Nodal signals can activate both Nodal and Antivin, whereas Antivin is thought to antagonise Nodal by binding either directly to it or to its receptor. In this paper we develop a mathematical model of this signalling network in a line of cells. We consider the heterodimer and receptor-mediated inhibition mechanisms separately and find that, in both cases, the restriction by Antivin to the range of Nodal signals corresponds to wave pinning in the model. Our analysis indicates that, provided Antivin diffuses faster than Nodal, either mechanism can robustly account for the experimental data. We argue that, in the case of Xenopus development, it is wave pinning, rather than Turing-type patterning, that is underlying Nodal-Antivin dynamics. This leads to several experimentally testable predictions, which are discussed. Furthermore, for heterodimer-mediated inhibition to prevent waves of Nodal expression from propagating, the Nodal-Antivin complex must be turned over, and diffusivity of the complex must be negligible. In the absence of molecular mechanisms regulating these, we suggest that Antivin restricts Nodal signals via receptor-mediated, and not heterodimer-mediated, inhibition. PMID:23070212

  12. Chiral Spin-Orbital Liquids with Nodal Lines.

    PubMed

    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 Ba_{2}YMoO_{6}. PMID:27419588

  13. 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.

  14. Anomalous thermodynamic power laws near topological transitions in nodal superconductors

    NASA Astrophysics Data System (ADS)

    Mazidian, B.; Quintanilla, J.; Hillier, A. D.; Annett, J. F.

    2013-12-01

    Unconventional superconductors are most frequently identified by the observation of power-law behavior on low-temperature thermodynamic or transport properties, such as specific heat. Here, we show that, in addition to the usual point and line nodes, a much wider class of different nodal types can occur. These new types of nodes typically occur when there are transitions between different types of gap node topology, for example, when point or line nodes first appear as a function of some physical parameter. We identify anomalous, noninteger thermodynamic power laws associated with these new nodal types, and give physical examples of superconductors in which they might be observed experimentally, including the noncentrosymmetric superconductor Li2Pd3-xPtxB.

  15. Nodal failure index approach to groundwater remediation design

    USGS Publications Warehouse

    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.

  16. Atrioventricular nodal reentrant tachycardia ablation and inferior vena cava agenesis.

    PubMed

    Galand, Vincent; Pavin, Dominique; Behar, Nathalie; Mabo, Philippe; Martins, Raphaël P

    2016-10-01

    Congenital anomalies of the inferior vena cava (IVC) are rare and very often diagnosed in asymptomatic patients during computed tomography performed for other purposes. These anomalies can have significant clinical implications, for example if electrophysiology procedures are needed. Diagnostic and ablation procedures are difficult since catheter manipulation and positioning are more complex. We present here a case of successful atrioventricular nodal reentrant tachycardia ablation in a patient with unexpected IVC agenesis, using an azygos route. PMID:27633734

  17. Nodal Basin Recurrence After Sentinel Lymph Node Biopsy for Melanoma

    PubMed Central

    Kretschmer, Lutz; Bertsch, Hans Peter; Zapf, Antonia; Mitteldorf, Christina; Satzger, Imke; Thoms, Kai-Martin; Völker, Bernward; Schön, Michael Peter; Gutzmer, Ralf; Starz, Hans

    2015-01-01

    Abstract The objective of this study was to analyze different types of nodal basin recurrence after sentinel lymph node biopsy (SLNB) for melanoma. Patients and Methods: Kaplan–Meier estimates and the Cox proportional hazards model were used to study 2653 patients from 3 German melanoma centers retrospectively. The estimated 5-year negative predictive value of SLNB was 96.4%. The estimated false-negative (FN) rates after 1, 2, 3, 5, and 10 years were 2.5%, 4.6%, 6.4%, 8.7%, and 12.6%, respectively. Independent factors associated with false negativity were older age, fewer SLNs excised, and head or neck location of the primary tumor. Compared with SLN-positive patients, the FNs had a significantly lower survival. In SLN-positive patients undergoing completion lymphadenectomy (CLND), the 5-year nodal basin recurrence rate was 18.3%. The recurrence rates for axilla, groin, and neck were 17.2%, 15.5%, and 44.1%, respectively. Significant factors predicting local relapse after CLND were older age, head, or neck location of the primary tumor, ulceration, deeper penetration of the metastasis into the SLN, tumor-positive CLND, and >2 lymph node metastases. All kinds of nodal relapse were associated with a higher prevalence of in-transit metastases. The FN rate after SLNB steadily increases over the observation period and should, therefore, be estimated by the Kaplan–Meier method. False-negativity is associated with fewer SLNs excised. The beneficial effect of CLND on nodal basin disease control varies considerably across different risk groups. This should be kept in mind about SLN-positive patients when individual decisions on prophylactic CLND are taken. PMID:26356697

  18. 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.

  19. 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.

  20. 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.

  1. A nodal domain theorem for integrable billiards in two dimensions

    SciTech Connect

    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.

  2. MCNP code

    SciTech Connect

    Cramer, S.N.

    1984-01-01

    The MCNP code is the major Monte Carlo coupled neutron-photon transport research tool at the Los Alamos National Laboratory, and it represents the most extensive Monte Carlo development program in the United States which is available in the public domain. The present code is the direct descendent of the original Monte Carlo work of Fermi, von Neumaum, and Ulam at Los Alamos in the 1940s. Development has continued uninterrupted since that time, and the current version of MCNP (or its predecessors) has always included state-of-the-art methods in the Monte Carlo simulation of radiation transport, basic cross section data, geometry capability, variance reduction, and estimation procedures. The authors of the present code have oriented its development toward general user application. The documentation, though extensive, is presented in a clear and simple manner with many examples, illustrations, and sample problems. In addition to providing the desired results, the output listings give a a wealth of detailed information (some optional) concerning each state of the calculation. The code system is continually updated to take advantage of advances in computer hardware and software, including interactive modes of operation, diagnostic interrupts and restarts, and a variety of graphical and video aids.

  3. Asynchronous collision integrators: Explicit treatment of unilateral contact with friction and nodal restraints

    PubMed Central

    Wolff, Sebastian; Bucher, Christian

    2013-01-01

    This article presents asynchronous collision integrators and a simple asynchronous method treating nodal restraints. Asynchronous discretizations allow individual time step sizes for each spatial region, improving the efficiency of explicit time stepping for finite element meshes with heterogeneous element sizes. The article first introduces asynchronous variational integration being expressed by drift and kick operators. Linear nodal restraint conditions are solved by a simple projection of the forces that is shown to be equivalent to RATTLE. Unilateral contact is solved by an asynchronous variant of decomposition contact response. Therein, velocities are modified avoiding penetrations. Although decomposition contact response is solving a large system of linear equations (being critical for the numerical efficiency of explicit time stepping schemes) and is needing special treatment regarding overconstraint and linear dependency of the contact constraints (for example from double-sided node-to-surface contact or self-contact), the asynchronous strategy handles these situations efficiently and robust. Only a single constraint involving a very small number of degrees of freedom is considered at once leading to a very efficient solution. The treatment of friction is exemplified for the Coulomb model. Special care needs the contact of nodes that are subject to restraints. Together with the aforementioned projection for restraints, a novel efficient solution scheme can be presented. The collision integrator does not influence the critical time step. Hence, the time step can be chosen independently from the underlying time-stepping scheme. The time step may be fixed or time-adaptive. New demands on global collision detection are discussed exemplified by position codes and node-to-segment integration. Numerical examples illustrate convergence and efficiency of the new contact algorithm. Copyright © 2013 The Authors. International Journal for Numerical Methods in

  4. Response of millet and sorghum to a varying water supply around the primary and nodal roots

    PubMed Central

    Rostamza, M.; Richards, R. A.; Watt, M.

    2013-01-01

    Background and Aims 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. Methods Sorghum and millet were grown in a split-pot system that allowed the primary and nodal roots to be watered separately. Key Results 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

  5. Para-aortic nodal metastases in cervical cancer: a blind spot in the International Federation of Gynecology and Obstetrics staging system: current diagnosis and management.

    PubMed

    Hwang, Lindsay; Bailey, April; Lea, Jayanthi; Albuquerque, Kevin

    2015-01-01

    In cervical cancer, para-aortic nodal (PALN) metastases at presentation is a strong indicator of poor prognosis. Despite this, International Federation of Gynecology and Obstetrics staging system does not require evaluation of lymph node involvement and does not incorporate clinically detected PALN into the staging system. In the USA, despite screening, a significant number of women still present at an advanced stage often with nodal metastases. While the presence of PALN metastases often indicates occult systemic disease, it is possible with modern therapies to provide long-term control of disease in a percentage of patients. We review the epidemiology, diagnosis and treatment of PALN metastases in cervical cancer outlining advances in modern imaging and combined modality therapies (surgery, chemotherapy and radiation therapy). PMID:25591841

  6. Differential diffusivity of Nodal and Lefty underlies a reaction-diffusion patterning system.

    PubMed

    Müller, Patrick; Rogers, Katherine W; Jordan, Ben M; Lee, Joon S; Robson, Drew; Ramanathan, Sharad; Schier, Alexander F

    2012-05-11

    Biological systems involving short-range activators and long-range inhibitors can generate complex patterns. Reaction-diffusion models postulate that differences in signaling range are caused by differential diffusivity of inhibitor and activator. Other models suggest that differential clearance underlies different signaling ranges. To test these models, we measured the biophysical properties of the Nodal/Lefty activator/inhibitor system during zebrafish embryogenesis. Analysis of Nodal and Lefty gradients revealed that Nodals have a shorter range than Lefty proteins. Pulse-labeling analysis indicated that Nodals and Leftys have similar clearance kinetics, whereas fluorescence recovery assays revealed that Leftys have a higher effective diffusion coefficient than Nodals. These results indicate that differential diffusivity is the major determinant of the differences in Nodal/Lefty range and provide biophysical support for reaction-diffusion models of activator/inhibitor-mediated patterning.

  7. Elsevier Trophoblast Research Award lecture: The multifaceted role of Nodal signaling during mammalian reproduction.

    PubMed

    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.

  8. Differential diffusivity of Nodal and Lefty underlies a reaction-diffusion patterning system

    PubMed Central

    Müller, Patrick; Rogers, Katherine W.; Jordan, Ben M.; Lee, Joon S.; Robson, Drew; Ramanathan, Sharad; Schier, Alexander F.

    2012-01-01

    Biological systems involving short-range activators and long-range inhibitors can generate complex patterns. Reaction-diffusion models postulate that differences in signaling range are caused by differential diffusivity of inhibitor and activator. Other models suggest that differential clearance underlies different signaling ranges. To test these models, we measured the biophysical properties of the Nodal/Lefty activator/inhibitor system during zebrafish embryogenesis. Analysis of Nodal and Lefty gradients reveals that Nodals have a shorter range than Lefty proteins. Pulse-labelinganalysis indicates that Nodals and Leftys have similar clearance kinetics, whereas fluorescence recovery assays reveal that Leftys have a higher effective diffusion coefficient than Nodals. These results indicate that differential diffusivity is the major determinant of the differences in Nodal/Lefty range and provide biophysical support for reaction-diffusion models of activator/inhibitor-mediated patterning. PMID:22499809

  9. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) verification and validation plan. version 1.

    SciTech Connect

    Bartlett, Roscoe Ainsworth; Arguello, Jose Guadalupe, Jr.; Urbina, Angel; Bouchard, Julie F.; Edwards, Harold Carter; Freeze, Geoffrey A.; Knupp, Patrick Michael; Wang, Yifeng; Schultz, Peter Andrew; Howard, Robert; McCornack, Marjorie Turner

    2011-01-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. To meet this objective, NEAMS Waste IPSC M&S capabilities will be applied to challenging spatial domains, temporal domains, multiphysics couplings, and multiscale couplings. A strategic verification and validation (V&V) goal is to establish evidence-based metrics for the level of confidence in M&S codes and capabilities. Because it is economically impractical to apply the maximum V&V rigor to each and every M&S capability, M&S capabilities will be ranked for their impact on the performance assessments of various components of the repository systems. Those M&S capabilities with greater impact will require a greater level of confidence and a correspondingly greater investment in V&V. This report includes five major components: (1) a background summary of the NEAMS Waste IPSC to emphasize M&S challenges; (2) the conceptual foundation for verification, validation, and confidence assessment of NEAMS Waste IPSC M&S capabilities; (3) specifications for the planned verification, validation, and confidence-assessment practices; (4) specifications for the planned evidence information management system; and (5) a path forward for the incremental implementation of this V&V plan.

  10. Lattice physics capabilities of the SCALE code system using TRITON

    SciTech Connect

    DeHart, M. D.

    2006-07-01

    This paper describes ongoing calculations used to validate the TRITON depletion module in SCALE for light water reactor (LWR) fuel lattices. TRITON has been developed to provide improved resolution for lattice physics mixed-oxide fuel assemblies as programs to burn such fuel in the United States begin to come online. Results are provided for coupled TRITON/PARCS analyses of an LWR core in which TRITON was employed for generation of appropriately weighted few-group nodal cross-sectional sets for use in core-level calculations using PARCS. Additional results are provided for code-to-code comparisons for TRITON and a suite of other depletion packages in the modeling of a conceptual next-generation boiling water reactor fuel assembly design. Results indicate that the set of SCALE functional modules used within TRITON provide an accurate means for lattice physics calculations. Because the transport solution within TRITON provides a generalized-geometry capability, this capability is extensible to a wide variety of non-traditional and advanced fuel assembly designs. (authors)

  11. 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.

  12. Evaluation of the use of nodal methods for MTR neutronic analysis

    SciTech Connect

    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.

  13. 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.

  14. NESTLE: Few-group neutron diffusion equation solver utilizing the nodal expansion method for eigenvalue, adjoint, fixed-source steady-state and transient problems

    SciTech Connect

    Turinsky, P.J.; Al-Chalabi, R.M.K.; Engrand, P.; Sarsour, H.N.; Faure, F.X.; Guo, W.

    1994-06-01

    NESTLE is a FORTRAN77 code that solves the few-group neutron diffusion equation utilizing the Nodal Expansion Method (NEM). NESTLE can solve the eigenvalue (criticality); eigenvalue adjoint; external fixed-source steady-state; or external fixed-source. or eigenvalue initiated transient problems. The code name NESTLE originates from the multi-problem solution capability, abbreviating Nodal Eigenvalue, Steady-state, Transient, Le core Evaluator. The eigenvalue problem allows criticality searches to be completed, and the external fixed-source steady-state problem can search to achieve a specified power level. Transient problems model delayed neutrons via precursor groups. Several core properties can be input as time dependent. Two or four energy groups can be utilized, with all energy groups being thermal groups (i.e. upscatter exits) if desired. Core geometries modelled include Cartesian and Hexagonal. Three, two and one dimensional models can be utilized with various symmetries. The non-linear iterative strategy associated with the NEM method is employed. An advantage of the non-linear iterative strategy is that NSTLE can be utilized to solve either the nodal or Finite Difference Method representation of the few-group neutron diffusion equation.

  15. Pharmacologic intervention in axonal excitability: in vivo assessment of nodal persistent sodium currents in human neuropathies.

    PubMed

    Kuwabara, Satoshi; Misawa, Sonoko

    2008-01-01

    Axonal excitability testing can provide new insights into the ionic mechanisms underlying the pathophysiology of hyperexcitability of motor and sensory axons in human neuropathies. Threshold tracking was developed in the 1990's to non-invasively measure a number of axonal excitability indices that depend on sodium and potassium channel function, and this makes it possible to monitor the effects of pharmacologic intervention with ion channel modulators. This paper reviews recent advances in ionic-pathophysiological studies in humans. (1) Neuropathic pain or muscle cramp/fasciculation is partly caused by hyperexcitability of the injured axons. The enhanced excitability can result from altered ion channel function; such as an increase in persistent sodium currents. Persistent sodium currents can be reliably estimated using threshold tracking. In peripheral neuropathy, persistent sodium currents usually increase possibly due to over-expression of sodium channels associated with axonal regeneration, and could be responsible for ectopic firings. Administration of sodium channel blockers such as mexiletine, results in marked alleviation of muscle cramping in parallel with a decrease in nodal persistent sodium currents. (2) In diabetic neuropathy, the activation of the polyol pathway mediated by an enzyme, aldose reductase, leads to reduced Na(+)/K(+) pump activity, and intra-axonal sodium accumulation; sodium currents are reduced presumably due to decreased trans-axonal sodium gradient. Aldose reductase inhibitiors improve nodal sodium currents, as well as nerve conduction, and this can be objectively assessed by threshold tracking. Studies of ion-channel pathophysiology in human subjects have recently begun. Investigating ionic mechanisms by monitoring the corresponding ionic currents. is of clinical relevance, because once a specific ionic conductance is identified, pharmacologic blocking or modulation could provide a new therapeutic option. PMID:20021424

  16. Descents and nodal load in scale-free networks

    NASA Astrophysics Data System (ADS)

    Bareinboim, Elias; Barbosa, Valmir C.

    2008-04-01

    The load of a node in a network is the total traffic going through it when every node pair sustains a uniform bidirectional traffic between them on shortest paths. We express nodal load in terms of the more elementary notion of a node’s descents in breadth-first-search [(BFS) or shortest-path] trees and study both the descent and nodal-load distributions in the case of scale-free networks. Our treatment is both semianalytical (combining a generating-function formalism with simulation-derived BFS branching probabilities) and computational for the descent distribution; it is exclusively computational in the case of the load distribution. Our main result is that the load distribution, even though it can be disguised as a power law through subtle (but inappropriate) binning of the raw data, is in fact a succession of sharply delineated probability peaks, each of which can be clearly interpreted as a function of the underlying BFS descents. This find is in stark contrast with previously held belief, based on which a power law of exponent -2.2 was conjectured to be valid regardless of the exponent of the power-law distribution of node degrees.

  17. Regional non-nodal metastases of cutaneous melanoma.

    PubMed

    Cascinelli, N; Bufalino, R; Marolda, R; Belli, F; Nava, M; Galluzzo, D; Santinami, M; Levene, A

    1986-06-01

    The authors studied the prognosis of patients with so called local recurrences, satellites and in-transit metastases from cutaneous melanoma on the basis of 291 patients. These are the 19.3% of the 1503 patients with stage I and II melanoma originally submitted to surgical treatment at the National Cancer Institute of Milano (Italy). The majority of patients were males (M/F = 0.7): 102 had local recurrence, 99 in-transit metastases, 24 satellites and 66 both local and in-transit metastases. Regional non-nodal metastases were not related with the site of origin, and inadequate treatment of primary. These metastases were more frequently observed in patients who were submitted to regional node dissection no matter whether in discontinuity or in continuity with primary tumor. The frequency of regional non-nodal metastases was found to increase with increasing thickness of primary melanoma or, in stage II patients, with the number of involved nodes. Local and in-transit metastases were related with prognostic criteria in the same way. The overall survival was very close between in-transit and local metastases. Similar survival rates were observed comparing regional non-nodes and disseminated cutaneous and subcutaneous metastases. The authors conclude that the distinction between local recurrences, satellites and in-transit metastases is artificial and that these metastatic events are not prognostically dissimilar from metastases in distant skin areas.

  18. Nodal Diffusion Burnable Poison Treatment for Prismatic Reactor Cores

    SciTech Connect

    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.

  19. 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.

  20. Extrapolation of critical Rayleigh values using static nodal integral methods

    SciTech Connect

    Wilson, G.L.; Rydin, R.A.

    1988-01-01

    The Benard problem is the study of the convective motion of a fluid in a rectangular cavity that is uniformly heated form below. Flow bifurcation in the cavity is a function of the Rayleigh number (Ra). The time-dependent nodal integral method (TDNIM) has been reported previously; its development leads to a set of 11 equations per node. The static nodal integral method (SNIM) was derived from the TDNIM by forcing the dependent variable at adjacent time steps (one of the velocity components or temperature) to take on the node integral average value. The paper summarizes the SNIM calculation of Ra for mesh sizes ranging from 4 x 4 to 24 x 24. The numerical calculation of Ra is within plus or minus one-half unit. The relative errors are calculated based on the obtained extrapolated value of Ra{sub best}* = 2584. The paper also summarizes three-point schemes used with increasingly finer mesh combinations. This approach avoids the contamination of the results with a coarse mesh; however, the calculation on n is very sensitive to small changes in the numerical values obtained for Ra*. In this approach, the extrapolated values quickly converge to Ra*{sub e} between 2583 and 2584 with n {approx}2.0 as desired, and give a best value of Ra*{sub best} = 2584.

  1. The effects of nodality on the formation of equivalence classes.

    PubMed

    Fields, L; Adams, B J; Verhave, T; Newman, S

    1990-05-01

    A four-member equivalence class (A----B----C----D) can be formed by training AB, BC, and CD. The nodal stimuli, B and C, mediate all of the derivative (transitive and equivalence) relations in the class. The derivative relations AC, CA, BD, and DB are separated by one node, whereas AD and DA are separated by two nodes. How do the number of nodes that separate the stimuli in a derivative relation influence the induction of stimulus control exerted by that relation? Seven college students learned two four-member classes made up of nonsense syllables. After training, all derivative relations were presented repeatedly without informative feedback. Stimulus control exerted by each derivative relation was assessed concurrently. For the 7 subjects, control exerted by the derivative relations increased gradually with repeated presentations. With 6 of the 7 subjects, the one-node relations exerted more control than the two-node relations during the process. However, the disparity between the one- and two-node relations decreased with repeated presentations. Eventually, all derivative relations exerted complete control. The control exerted by derivative relations during induction was inversely related to the number of nodes separating the terms in the derivative relations. These results demonstrate that nodal distance is a determinant of the relatedness of stimuli in equivalence classes. The findings are discussed in terms of remote association, semantic memory networks, and the study of transitive inference.

  2. A finite element code for electric motor design

    NASA Technical Reports Server (NTRS)

    Campbell, C. Warren

    1994-01-01

    FEMOT is a finite element program for solving the nonlinear magnetostatic problem. This version uses nonlinear, Newton first order elements. The code can be used for electric motor design and analysis. FEMOT can be embedded within an optimization code that will vary nodal coordinates to optimize the motor design. The output from FEMOT can be used to determine motor back EMF, torque, cogging, and magnet saturation. It will run on a PC and will be available to anyone who wants to use it.

  3. Multigroup 3-Dimensional Neutron Diffusion Nodal Code System with Thermohydraulic Feedbacks.

    1994-02-07

    Version 01 GNOMER is a program which solves the multigroup neutron diffusion equation on coarse mesh in 1D, 2D, and 3D Cartesian geometry. The program is designed to calculate the global core power distributions (with thermohydraulic feedbacks) as well as power distributions and homogenized cross sections over a fuel assembly.

  4. Distal end of the atrioventricular nodal artery predicts the risk of atrioventricular block during slow pathway catheter ablation of atrioventricular nodal re-entrant tachycardia

    PubMed Central

    Lin, J; Huang, S; Lai, L; Lin, L; Chen, J; Tseng, Y; Lien, W

    2000-01-01

    OBJECTIVE—To search for a reliable anatomical landmark within Koch's triangle to predict the risk of atrioventricular (AV) block during radiofrequency slow pathway catheter ablation of AV nodal re-entrant tachycardia (AVNRT).
PATIENTS AND METHODS—To test the hypothesis that the distal end of the AV nodal artery represents the anatomical location of the AV node, and thus could be a useful landmark for predicting the risk of AV block, 128 consecutive patients with AVNRT receiving slow pathway catheter ablation were prospectively studied in two phases. In phase I (77 patients), angiographic demonstration of the AV nodal artery and its ending was performed at the end of the ablation procedure, whereas in the subsequent phase II study (51 patients), the angiography was performed immediately before catheter ablation to assess the value of identifying this new landmark in reducing the risk of AV block. Multiple electrophysiologic and anatomical parameters were analysed. The former included the atrial activation sequence between the His bundle recording site (HBE) and the coronary sinus orifice or the catheter ablation site, either during AVNRT or during sinus rhythm. The latter included the spatial distances between the distal end of the AV nodal artery and the HBE and the final catheter ablation site, and the distance between the HBE and the tricuspid border at the coronary sinus orifice floor.
RESULTS—In phase I, nine of the 77 patients had complications of transient (seven patients) or permanent (two patients) complete AV block during stepwise, anatomy guided slow pathway catheter ablation. These nine patients had a wider distance between the HBE and the distal end of the AV nodal artery, and a closer approximation of the catheter ablation site to the distal end of the AV nodal artery, which independently predicted the risk of AV block. In contrast, none of the available electrophysiologic parameters were shown to be reliable. When the distance between

  5. Beam Elements with Trapezoidal Cross Section Deformation Modes Based on the Absolute Nodal Coordinate Formulation

    NASA Astrophysics Data System (ADS)

    Matikainen, Marko K.; Dmitrochenko, Oleg; Mikkola, Aki

    2010-09-01

    In this study, higher order beam elements are developed based on the absolute nodal coordinate formulation. The absolute nodal coordinate formulation is a finite element procedure that was recently proposed for flexible multibody applications. Many different elements based on the absolute nodal coordinate formulation are introduced, but still the beam elements are not able to describe the trapezoidal cross section mode. This leads to the locking phenomena, and therefore, the beam elements based on the absolute nodal coordinate formulation with three dimensional elasticity converge to an inexact solution. In order to avoid the locking phenomena, the trapezoidal cross section deformation mode is included in the beam elements based on the absolute nodal coordinate with additional degrees of freedom. The proper description for the trapezoidal cross section deformation is important for the continuum beam elements based on three-dimensional elasticity where the material model is often based on general continuum mechanics.

  6. Embryonic and tumorigenic pathways converge via Nodal signaling: role in melanoma aggressiveness.

    PubMed

    Topczewska, Jolanta M; Postovit, Lynne-Marie; Margaryan, Naira V; Sam, Anthony; Hess, Angela R; Wheaton, William W; Nickoloff, Brian J; Topczewski, Jacek; Hendrix, Mary J C

    2006-08-01

    Bidirectional cellular communication is integral to both cancer progression and embryological development. In addition, aggressive tumor cells are phenotypically plastic, sharing many properties with embryonic cells. Owing to the similarities between these two types of cells, the developing zebrafish can be used as a biosensor for tumor-derived signals. Using this system, we show that aggressive melanoma cells secrete Nodal (a potent embryonic morphogen) and consequently can induce ectopic formation of the embryonic axis. We further show that Nodal is present in human metastatic tumors, but not in normal skin, and thus may be involved in melanoma pathogenesis. Inhibition of Nodal signaling reduces melanoma cell invasiveness, colony formation and tumorigenicity. Nodal inhibition also promotes the reversion of melanoma cells toward a melanocytic phenotype. These data suggest that Nodal signaling has a key role in melanoma cell plasticity and tumorigenicity, thereby providing a previously unknown molecular target for regulating tumor progression. PMID:16892036

  7. Nodal promotes invasive phenotypes via a Mitogen Activated Protein Kinase-dependent pathway

    PubMed Central

    Quail, DF; Zhang, G; Findlay, SD; Hess, DA; Postovit, LM

    2016-01-01

    The progression of cancer from localized to invasive disease is requisite for metastasis, and is often characterized by epithelial-to-mesenchymal transition (EMT) and alterations in cellular adhesion and migration. Studies have shown that this transition is associated with an up-regulation of embryonic stem cell-associated genes, resulting in a dedifferentiated phenotype and poor patient prognosis. Nodal is an embryonic factor that plays a critical role in promoting early invasive events during development. Nodal is silenced as stem cells differentiate; however, it re-emerges in adult life during placentation and mammary gland development, and is aberrantly expressed in many cancers. Here, we show that Nodal over-expression, in poorly-invasive breast cancer and choriocarcinoma cells, causes increased invasion and migration in vitro. Furthermore, we show that Nodal over-expression in these epithelial cancer types induces an EMT-like event concomitant with the internalization of E-Cadherin. This ability of Nodal to promote cellular invasion and EMT-like phenomena is dependent upon the phosphorylation of ERK1/2. Since Nodal normally signals through SMADs, these findings lend insight into an alternative pathway that is hijacked by this protein in cancer. To evaluate the clinical implications of our results, we show that Nodal inhibition reduces liver tumor burden in a model of spontaneous breast cancer metastasis in vivo, and that Nodal loss-of-function in aggressive breast cancer lines results in a decrease in invasive phenotypes. Our results demonstrate that Nodal is involved in promoting invasion in multiple cellular contexts, and that Nodal inhibition may be useful as a therapeutic target for patients with progressive disease. PMID:23334323

  8. 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.

  9. 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.

  10. Typical nodal calcifications in the maxillofacial region: a case report

    PubMed Central

    Wu, Guomin; Sun, Xiumei; Ni, Shilei; Zhang, Zhimin

    2014-01-01

    Multiple nodal calcifications in the maxillofacial region are very rare. This case report described a 49-year-old female patient diagnosed with calcified lymph nodes due to chronic inflammation of the lymphatic nodes, including the parotid lymphatic nodes, the posterior auricular lymphatic nodes and submandibular lymphatic nodes in the right maxillofacial region. In clinical practice, we conducted ultrasonography, three-dimensional reconstruction of CT and sialography make a preliminary diagnosis. Then we took surgery, while removing the calcified blocks within the lymphatic node and cleaning the wound cavity. After surgery, we used anti-inflammatory therapy for one week. Six months follow-up indicated no evidence of other calcified lymph nodes infection. PMID:25356188

  11. Contemporary Management of Recurrent Nodal Disease in Differentiated Thyroid Carcinoma.

    PubMed

    Na'ara, Shorook; Amit, Moran; Fridman, Eran; Gil, Ziv

    2016-01-28

    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.

  12. Coexistence of Weyl fermion and massless triply degenerate nodal points

    NASA Astrophysics Data System (ADS)

    Weng, Hongming; Fang, Chen; Fang, Zhong; Dai, Xi

    2016-10-01

    By using first-principles calculations, we propose that WC-type ZrTe is a new type of topological semimetal (TSM). It has six pairs of chiral Weyl nodes in its first Brillouin zone, but it is distinguished from other existing TSMs by having an additional two paris of massless fermions with triply degenerate nodal points as proposed in the isostructural compounds TaN and NbN. The mirror symmetry, threefold rotational symmetry, and time-reversal symmetry require all of the Weyl nodes to have the same velocity vectors and locate at the same energy level. The Fermi arcs on different surfaces are shown, which may be measured by future experiments. It demonstrates that the "material universe" can support more intriguing particles simultaneously.

  13. ProNodal acts via FGFR3 to govern duration of Shh expression in the prechordal mesoderm.

    PubMed

    Ellis, Pamela S; Burbridge, Sarah; Soubes, Sandrine; Ohyama, Kyoji; Ben-Haim, Nadav; Chen, Canhe; Dale, Kim; Shen, Michael M; Constam, Daniel; Placzek, Marysia

    2015-11-15

    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.

  14. ProNodal acts via FGFR3 to govern duration of Shh expression in the prechordal mesoderm

    PubMed Central

    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

  15. Nicalin and its binding partner Nomo are novel Nodal signaling antagonists.

    PubMed

    Haffner, Christof; Frauli, Mélanie; Topp, Stephanie; Irmler, Martin; Hofmann, Kay; Regula, Jörg T; Bally-Cuif, Laure; Haass, Christian

    2004-08-01

    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. PMID:15257293

  16. The embryonic morphogen, Nodal, is associated with channel-like structures in human malignant melanoma xenografts.

    PubMed

    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.

  17. Application of the Absolute Nodal Co-Ordinate Formulation to Multibody System Dynamics

    NASA Astrophysics Data System (ADS)

    Escalona, J. L.; Hussien, H. A.; Shabana, A. A.

    1998-07-01

    The floating frame of reference formulation is currently the most widely used approach in flexible multibody simulations. The use of this approach, however, has been limited to small deformation problems. In this investigation, the computer implementation of the newabsolute nodal co-ordinate formulationand its use in the small and large deformation analysis of flexible multibody systems that consist of interconnected bodies are discussed. While in the floating frame of reference formulation a mixed set of absolute reference and local elastic co-ordinates are used, in the absolute nodal co-ordinate formulation only absolute co-ordinates are used. In the absolute nodal co-ordinate formulation, new interpretation of the nodal co-ordinates of the finite elements is used. No infinitesimal or finite rotations are used as nodal co-ordinates from beams and plates, instead, global slopes are used to define the element nodal co-ordinates. Using this interpretation of the element co-ordinates, beams and plates can be considered as isoparametric elements, and as a result, exact modelling of the rigid body dynamics can be obtained using the element shape function and the absolute nodal co-ordinates. Unlike the floating frame of reference approach, no co-ordinate transformation is required in order to determine the element inertia. The mass matrix of the finite elements is a constant matrix, and therefore, the centrifugal and Coriolis forces are equal to zero when the absolute nodal co-ordinate formulation is used. Another advantage of using the absolute nodal co-ordinate formulation in the dynamic simulation of multibody systems is its simplicity in imposing some of the joint constraints and also its simplicity in formulating the generalized forces due to spring-damper elements. The results obtained in this investigation show an excellent agreement with the results obtained using the floating frame of reference formulation when large rotation-small deformation problems are

  18. Nodal signaling is required for closure of the anterior neural tube in zebrafish

    PubMed Central

    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

  19. The accuracy of preoperative axillary nodal staging in primary breast cancer by ultrasound is modified by nodal metastatic load and tumor biology

    PubMed Central

    Dihge, Looket; Grabau, Dorthe A.; Rasmussen, Rogvi W.; Bendahl, Pär-Ola; Rydén, Lisa

    2016-01-01

    Abstract Background The outcome of axillary ultrasound (AUS) with fine-needle aspiration biopsy (FNAB) in the diagnostic work-up of primary breast cancer has an impact on therapy decisions. We hypothesize that the accuracy of AUS is modified by nodal metastatic burden and clinico-pathological characteristics. Material and methods The performance of AUS and AUS-guided FNAB for predicting nodal metastases was assessed in a prospective breast cancer cohort subjected for surgery during 2009–2012. Predictors of accuracy were included in multivariate analysis. Results AUS had a sensitivity of 23% and a specificity of 95%, while AUS-guided FNAB obtained 73% and 100%, respectively. AUS-FNAB exclusively detected macro-metastases (median four metastases) and identified patients with more extensive nodal metastatic burden in comparison with sentinel node biopsy. The accuracy of AUS was affected by metastatic size (OR 1.11), obesity (OR 2.46), histological grade (OR 4.43), and HER2-status (OR 3.66); metastatic size and histological grade were significant in the multivariate analysis. Conclusions The clinical utility of AUS in low-risk breast cancer deserves further evaluation as the accuracy decreased with a low nodal metastatic burden. The diagnostic performance is modified by tumor and clinical characteristics. Patients with nodal disease detected by AUS-FNAB represent a group for whom neoadjuvant therapy should be considered. PMID:27050668

  20. Embryonic Morphogen Nodal Is Associated with Progression and Poor Prognosis of Hepatocellular Carcinoma

    PubMed Central

    Jia, Wei-Dong; Xu, Ge-Liang; Ma, Jin-Liang; Ren, Yun; Chen, Hao; Sun, Si-Nan; Huang, Mei; Li, Jian-Sheng

    2014-01-01

    Background Nodal, a TGF-β-related embryonic morphogen, is involved in multiple biologic processes. However, the expression of Nodal in hepatocellular carcinoma (HCC) and its correlation with tumor angiogenesis, epithelial-mesenchymal transition, and prognosis is unclear. Methods We used real-time PCR and Western blotting to investigate Nodal expression in 6 HCC cell lines and 1 normal liver cell line, 16 pairs of tumor and corresponding paracarcinomatous tissues from HCC patients. Immunohistochemistry was performed to examine Nodal expression in HCC and corresponding paracarcinomatous tissues from 96 patients. CD34 and Vimentin were only examined in HCC tissues of patients mentioned above. Nodal gene was silenced by shRNA in MHCC97H and HCCLM3 cell lines, and cell migration and invasion were detected. Statistical analyses were applied to evaluate the prognostic value and associations of Nodal expression with clinical parameters. Results Nodal expression was detected in HCC cell lines with high metastatic potential alone. Nodal expression is up-regulated in HCC tissues compared with paracarcinomatous and normal liver tissues. Nodal protein was expressed in 70 of the 96 (72.9%) HCC tumors, and was associated with vascular invasion (P = 0.000), status of metastasis (P = 0.004), AFP (P = 0.049), ICGR15 (indocyanine green retention rate at 15 min) (P = 0.010) and tumor size (P = 0.000). High Nodal expression was positively correlated with high MVD (microvessal density) (P = 0.006), but not with Vimentin expression (P = 0.053). Significantly fewer migrated and invaded cells were seen in shRNA group compared with blank group and negative control group (P<0.05). High Nodal expression was found to be an independent factor for predicting overall survival of HCC. Conclusions Our study demonstrated that Nodal expression is associated with aggressive characteristics of HCC. Its aberrant expression may be a predictive factor of unfavorable prognosis

  1. Seals Flow Code Development

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In recognition of a deficiency in the current modeling capability for seals, an effort was established by NASA to develop verified computational fluid dynamic concepts, codes, and analyses for seals. The objectives were to develop advanced concepts for the design and analysis of seals, to effectively disseminate the information to potential users by way of annual workshops, and to provide experimental verification for the models and codes under a wide range of operating conditions.

  2. Effectiveness of prophylactic retropharyngeal lymph node irradiation in patients with locally advanced head and neck cancer

    PubMed Central

    2012-01-01

    Background The aim of the study is to assess the effectiveness of intensity-modulated radiotherapy (IMRT) or image-guided radiotherapy (IGRT) for the prevention of retropharyngeal nodal recurrences in locally advanced head and neck cancer. Methods A retrospective review of 76 patients with head and neck cancer undergoing concurrent chemoradiation or postoperative radiotherapy with IMRT or IGRT who were at risk for retropharyngeal nodal recurrences because of anatomic site (hypopharynx, nasopharynx, oropharynx) and/or the presence of nodal metastases was undertaken. The prevalence of retropharyngeal nodal recurrences was assessed on follow-up positron emission tomography (PET)-CT scans. Results At a median follow-up of 22 months (4–53 months), no patient developed retropharyngeal nodal recurrences. Conclusion Prophylactic irradiation of retropharyngeal lymph nodes with IMRT or IGRT provides effective regional control for individuals at risk for recurrence in these nodes. PMID:22708791

  3. Micropropagation of Calophyllum brasiliense (Cambess.) from nodal segments.

    PubMed

    Silveira, S S; Cordeiro-Silva, R; Degenhardt-Goldbach, J; Quoirin, M

    2016-05-01

    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.

  4. Micropropagation of commercially cultivated Henna (Lawsonia inermis) using nodal explants.

    PubMed

    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.

  5. Heterogeneous nodal responses in cascade dynamics on multiplex networks

    NASA Astrophysics Data System (ADS)

    Lee, Kyu-Min; Brummitt, Charles D.; Goh, Kwang-Il

    2014-03-01

    Structure and dynamics of multiplex network systems have been intensively studied recently, revealing nontrivial results such as facilitated cascading failures and new type of phase transitions unforeseen in the single-level systems. However, most studies about multi-layered, network of networks have mainly considered the case of single nodal response to multiple layers, that is, every node responds to the multiple layers in identical way. Most complex systems like human society, however, function not only through various kinds of relations but also through heterogeneous response behavior across agents, indicating a new level of complexity. To address it, here we formulate a threshold cascade model on multiplex networks with a mixture of two response functions: OR and AND rules. For the OR response, nodes are activated if enough neighbors in any layer are active, whereas for the AND response, the nodes activate only if enough neighbors in all layers are active. Coexistence of these two response rules is shown to control between facilitation and inhibition of cascading failures, and moreover, it can also control the type of transitions to global cascades between continuous and discontinuous ones. We will discuss the implication of the results in the context of social dynamics.

  6. Micropropagation of Calophyllum brasiliense (Cambess.) from nodal segments.

    PubMed

    Silveira, S S; Cordeiro-Silva, R; Degenhardt-Goldbach, J; Quoirin, M

    2016-05-01

    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. PMID:27143061

  7. Recommendations for Radiotherapy Technique and Dose in Extra-nodal Lymphoma.

    PubMed

    Hoskin, P J; Díez, P; Gallop-Evans, E; Syndikus, I; Bates, A; Bayne, M

    2016-01-01

    Extra-nodal sites may be involved in around 40% of patients with non-Hodgkin lymphoma. The general principles for target volume delineation in this setting are presented, together with specific examples. In general, the entire organ affected should be encompassed in the clinical target volume with an expansion of at least 10 mm, increased in some instances to account for patterns of potential lymphatic flow. Adjacent lymph nodes may be treated using standard techniques for nodal irradiation. Doses for extra-nodal lymphoma follow the same principles as nodal lymphoma, delivering 30 Gy in 15 fractions for Hodgkin and aggressive non-Hodgkin lymphoma and 24 Gy in 12 fractions for indolent lymphomas, with the exception of certain palliative situations, mycosis fungoides, central nervous system lymphoma and natural killer/T-cell lymphoma.

  8. Relation between finite element methods and nodal methods in transport theory

    SciTech Connect

    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.

  9. Dose-dependent Nodal/Smad signals pattern the early mouse embryo.

    PubMed

    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. PMID:24704361

  10. Recommendations for Radiotherapy Technique and Dose in Extra-nodal Lymphoma.

    PubMed

    Hoskin, P J; Díez, P; Gallop-Evans, E; Syndikus, I; Bates, A; Bayne, M

    2016-01-01

    Extra-nodal sites may be involved in around 40% of patients with non-Hodgkin lymphoma. The general principles for target volume delineation in this setting are presented, together with specific examples. In general, the entire organ affected should be encompassed in the clinical target volume with an expansion of at least 10 mm, increased in some instances to account for patterns of potential lymphatic flow. Adjacent lymph nodes may be treated using standard techniques for nodal irradiation. Doses for extra-nodal lymphoma follow the same principles as nodal lymphoma, delivering 30 Gy in 15 fractions for Hodgkin and aggressive non-Hodgkin lymphoma and 24 Gy in 12 fractions for indolent lymphomas, with the exception of certain palliative situations, mycosis fungoides, central nervous system lymphoma and natural killer/T-cell lymphoma. PMID:26456507

  11. ANOVA-HDMR structure of the higher order nodal diffusion solution

    SciTech Connect

    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)

  12. Nodal signaling in Xenopus gastrulae is cell-autonomous and patterned by beta-catenin.

    PubMed

    Hashimoto-Partyka, Minako K; Yuge, Masahiro; Cho, Ken W Y

    2003-01-01

    The classical three-signal model of amphibian mesoderm induction and more recent modifications together propose that an activin-like signaling activity is uniformly distributed across the vegetal half of the Xenopus blastula and that this activity contributes to mesoderm induction. In support of this, we have previously shown that the activin-response element (DE) of the goosecoid promoter is uniformly activated across the vegetal half of midgastrula-stage embryos. Here, we further examine the nature of this activity by measuring DE activation by endogenous signals over time. We find that the spatiotemporal pattern of DE activation is much more dynamic than was previously appreciated and also conclude that DE(6X)Luc activity reflects endogenous nodal signaling in the embryo. Using both the DE(6X)Luc construct and endogenous Xbra and Xgsc expression as read-outs for nodal activity, and the cleavage-mutant version of Xnr2 (CmXnr2) to regionally suppress endogenous nodal activity, we demonstrate that nodal signals act cell-autonomously in Xenopus gastrulae. Nodal-expressing cells are unable to rescue either reporter gene activation or target gene expression in distant nodal-deficient cells, suggesting that nodals function at short range in this context. Finally, we show that DE activation by endogenous signals occurs in the absence of dorsal beta-catenin-mediated signaling, but that the timing of dorsal initiation is altered. We conclude that nodal signals in Xenopus gastrulae function cell autonomously at short ranges and that the spatiotemporal pattern of this signaling along the dorsoventral axis is regulated by maternal Wnt-like signaling. PMID:12490202

  13. High Risk of Lateral Nodal Metastasis in Lateral Solitary Solid Papillary Thyroid Cancer.

    PubMed

    Lai, Xing-Jian; Zhang, Bo; Jiang, Yu-Xin; Li, Jian-Chu; Zhao, Rui-Na; Yang, Xiao; Zhang, Qing; Zhang, Xiao-Yan; Li, Wen-Bo; Zhu, Shen-Ling

    2016-01-01

    We explored the relationship between ultrasonic intra-thyroidal location and neck node metastasis pattern in solitary solid papillary thyroid cancer (PTC). Data on 186 patients were retrospectively reviewed. The association between several characteristics and neck node metastasis pattern were analyzed. Among the 186 thyroid nodules, age ≥45 y (p = 0.005), mass size ≥2 cm (p = 0.001), presence of calcifications (p < 0.001) and lateral nodal metastasis (p = 0.001) were significantly related to central nodal metastasis in multivariate analysis. Mass size ≥2 cm (p = 0.046) and central nodal metastasis (p = 0.002) were significantly related to lateral nodal metastasis in multivariate analysis. Location of an intra-thyroidal solitary solid PTC located non-adjacent to the trachea (lateral) was significantly related to lateral nodal metastasis (p = 0.043) compared with location of an intra-thyroidal solitary solid PTC adjacent to the trachea (medial or isthmus). Lateral lesions have a high risk of lateral nodal metastasis in solitary solid PTC.

  14. Undertreatment of patients with localized extranodal compared with nodal diffuse large B-cell lymphoma.

    PubMed

    Kuper-Hommel, Marion J J; van de Schans, Saskia A M; Vreugdenhil, Gerard; van Krieken, J Han; Coebergh, Jan-Willem W

    2013-08-01

    Population-based studies analyzing clinical implications of nodal versus extranodal (EN) presentation of diffuse large B-cell lymphoma (DLBCL) are scarce. We studied clinical differences and trends in incidence, treatment and survival of nodal and EN DLBCL in a population-based cohort. All patients newly diagnosed with localized (Ann Arbor stage [AAS] I and II) nodal (n = 5124) and EN (n = 4776) DLBCL, and primary mediastinal B-cell lymphoma (PMBL; n = 88), diagnosed between 1989 and 2010, were selected from the Netherlands Cancer Registry. Primary EN disease was correlated with older age and more favorable clinical stage (AAS I). The age standardized incidence rates for men with localized EN DLBCL, and for men and women with localized PMBL, increased significantly, whereas the age standardized incidence rates of all other subgroups remained stable. The stomach was the most common EN localization. Patients with EN disease received less chemotherapy and targeted therapy than their nodal counterparts, irrespective of age and period of diagnosis. Their 5-year overall survival (OS) was 48% vs. 54% in the nodal group, but in multivariate analysis primary extranodal presentation was not independently associated with inferior survival. This population-based study shows clinically relevant differences between localized nodal and EN DLBCL and PMBL. Since patients with EN were significantly less often optimally treated, we advocate better interaction between medical disciplines. PMID:23190406

  15. Solution and Study of the Two-Dimensional Nodal Neutron Transport Equation

    SciTech Connect

    Panta Pazos, Ruben; Biasotto Hauser, Eliete; Tullio de Vilhena, Marco

    2002-07-01

    In the last decade Vilhena and coworkers reported an analytical solution to the two-dimensional nodal discrete-ordinates approximations of the neutron transport equation in a convex domain. The key feature of these works was the application of the combined collocation method of the angular variable and nodal approach in the spatial variables. By nodal approach we mean the transverse integration of the SN equations. This procedure leads to a set of one-dimensional S{sub N} equations for the average angular fluxes in the variables x and y. These equations were solved by the old version of the LTS{sub N} method, which consists in the application of the Laplace transform to the set of nodal S{sub N} equations and solution of the resulting linear system by symbolic computation. It is important to recall that this procedure allow us to increase N the order of S{sub N} up to 16. To overcome this drawback we step forward performing a spectral painstaking analysis of the nodal S{sub N} equations for N up to 16 and we begin the convergence of the S{sub N} nodal equations defining an error for the angular flux and estimating the error in terms of the truncation error of the quadrature approximations of the integral term. Furthermore, we compare numerical results of this approach with those of other techniques used to solve the two-dimensional discrete approximations of the neutron transport equation. (authors)

  16. A quasi-static polynomial nodal method for nuclear reactor analysis

    SciTech Connect

    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.

  17. The Apelin receptor enhances Nodal/TGFβ signaling to ensure proper cardiac development

    PubMed Central

    Deshwar, Ashish R; Chng, Serene C; Ho, Lena; Reversade, Bruno; Scott, Ian C

    2016-01-01

    The Apelin receptor (Aplnr) is essential for heart development, controlling the early migration of cardiac progenitors. Here we demonstrate that in zebrafish Aplnr modulates Nodal/TGFβ signaling, a key pathway essential for mesendoderm induction and migration. Loss of Aplnr function leads to a reduction in Nodal target gene expression whereas activation of Aplnr by a non-peptide agonist increases the expression of these same targets. Furthermore, loss of Aplnr results in a delay in the expression of the cardiogenic transcription factors mespaa/ab. Elevating Nodal levels in aplnra/b morphant and double mutant embryos is sufficient to rescue cardiac differentiation defects. We demonstrate that loss of Aplnr attenuates the activity of a point source of Nodal ligands Squint and Cyclops in a non-cell autonomous manner. Our results favour a model in which Aplnr is required to fine-tune Nodal output, acting as a specific rheostat for the Nodal/TGFβ pathway during the earliest stages of cardiogenesis. DOI: http://dx.doi.org/10.7554/eLife.13758.001 PMID:27077952

  18. Uplink Coding

    NASA Technical Reports Server (NTRS)

    Pollara, Fabrizio; Hamkins, Jon; Dolinar, Sam; Andrews, Ken; Divsalar, Dariush

    2006-01-01

    This viewgraph presentation reviews uplink coding. The purpose and goals of the briefing are (1) Show a plan for using uplink coding and describe benefits (2) Define possible solutions and their applicability to different types of uplink, including emergency uplink (3) Concur with our conclusions so we can embark on a plan to use proposed uplink system (4) Identify the need for the development of appropriate technology and infusion in the DSN (5) Gain advocacy to implement uplink coding in flight projects Action Item EMB04-1-14 -- Show a plan for using uplink coding, including showing where it is useful or not (include discussion of emergency uplink coding).

  19. TGF-β promotes glioma cell growth via activating Nodal expression through Smad and ERK1/2 pathways

    SciTech Connect

    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.

  20. Coexistent Types of Atrioventricular Nodal Re-Entrant Tachycardia

    PubMed Central

    Marine, Joseph E.; Latchamsetty, Rakesh; Zografos, Theodoros; Tanawuttiwat, Tanyanan; Sheldon, Seth H.; Buxton, Alfred E.; Calkins, Hugh; Morady, Fred; Josephson, Mark E.

    2015-01-01

    Background— There is evidence that atypical fast–slow and typical atrioventricular nodal re-entrant tachycardia (AVNRT) do not use the same limb for fast conduction, but no data exist on patients who have presented with both typical and atypical forms of this tachycardia. We compared conduction intervals during typical and atypical AVNRT that occurred in the same patient. Methods and Results— In 20 of 1299 patients with AVNRT, both typical and atypical AVNRT were induced at electrophysiology study by pacing maneuvers and autonomic stimulation or occurred spontaneously. The mean age of the patients was 47.6±10.9 years (range, 32–75 years), and 11 patients (55%) were women. Tachycardia cycle lengths were 368.0±43.1 and 365.8±41.1 ms, and earliest retrograde activation was recorded at the coronary sinus ostium in 60% and 65% of patients with typical and atypical AVNRT, respectively. Thirteen patients (65%) displayed atypical AVNRT with fast–slow characteristics. By comparing conduction intervals during slow–fast and fast–slow AVNRT in the same patient, fast pathway conduction times during the 2 types of AVNRT were calculated. The mean difference between retrograde fast pathway conduction during slow–fast AVNRT and anterograde fast pathway conduction during fast–slow AVNRT was 41.8±39.7 ms and was significantly different when compared with the estimated between-measurement error (P=0.0055). Conclusions— Our data provide further evidence that typical slow–fast and atypical fast–slow AVNRT use different anatomic pathways for fast conduction. PMID:26155802

  1. Cluster analysis of contaminated sediment data: nodal analysis.

    PubMed

    Hartwell, S Ian; Claflin, Larry W

    2005-07-01

    The objective of the present study was to explore the use of multivariate statistical methods as a means to discern relationships between contaminants and biological and/or toxicological effects in a representative data set from the National Status and Trends (NS&T) Program. Data from the National Oceanic and Atmospheric Administration, NS&T Program's Bioeffects Survey of Delaware Bay, USA, were examined using various univariate and multivariate statistical techniques, including cluster analysis. Each approach identified consistent patterns and relationships between the three types of triad data. The analyses also identified factors that bias the interpretation of the data, primarily the presence of rare and unique species and the dependence of species distributions on physical parameters. Sites and species were clustered with the unweighted pair-group method using arithmetic averages clustering with the Jaccard coefficient that clustered species and sites into mutually consistent groupings. Pearson product moment correlation coefficients, normalized for salinity, also were clustered. The most informative analysis, termed nodal analysis, was the intersection of species cluster analysis with site cluster analysis. This technique produced a visual representation of species association patterns among site clusters. Site characteristics, such as salinity and grain size, not contaminant concentrations, appeared to be the primary factors determining species distributions. This suggests the sediment-quality triad needs to use physical parameters as a distinct leg from chemical concentrations to improve sediment-quality assessments in large bodies of water. Because the Delaware Bay system has confounded gradients of contaminants and physical parameters, analyses were repeated with data from northern Chesapeake Bay, USA, with similar results. PMID:16050601

  2. Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma

    PubMed Central

    Seol, Ki Ho

    2016-01-01

    Purpose To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Materials and Methods Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4–72 Gy (39.6–45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. Results The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. Conclusion No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC. PMID:27104162

  3. Sharing code.

    PubMed

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.

  4. Pyramid image codes

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1990-01-01

    All vision systems, both human and machine, transform the spatial image into a coded representation. Particular codes may be optimized for efficiency or to extract useful image features. Researchers explored image codes based on primary visual cortex in man and other primates. Understanding these codes will advance the art in image coding, autonomous vision, and computational human factors. In cortex, imagery is coded by features that vary in size, orientation, and position. Researchers have devised a mathematical model of this transformation, called the Hexagonal oriented Orthogonal quadrature Pyramid (HOP). In a pyramid code, features are segregated by size into layers, with fewer features in the layers devoted to large features. Pyramid schemes provide scale invariance, and are useful for coarse-to-fine searching and for progressive transmission of images. The HOP Pyramid is novel in three respects: (1) it uses a hexagonal pixel lattice, (2) it uses oriented features, and (3) it accurately models most of the prominent aspects of primary visual cortex. The transform uses seven basic features (kernels), which may be regarded as three oriented edges, three oriented bars, and one non-oriented blob. Application of these kernels to non-overlapping seven-pixel neighborhoods yields six oriented, high-pass pyramid layers, and one low-pass (blob) layer.

  5. Topological nodal-line fermions in spin-orbit metal PbTaSe2.

    PubMed

    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

    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.

  6. Topological nodal-line fermions in spin-orbit metal PbTaSe2

    DOE PAGES

    Bian, Guang; Chang, Tay-Rong; Sankar, Raman; Xu, Su-Yang; Zheng, Hao; Neupert, Titus; Chiu, Ching-Kai; Huang, Shin-Ming; Chang, Guoqing; Belopolski, Ilya; et al

    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

  7. Topological nodal-line fermions in spin-orbit metal PbTaSe2.

    PubMed

    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

  8. Topological nodal-line fermions in spin-orbit metal PbTaSe2

    NASA Astrophysics Data System (ADS)

    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

    2016-02-01

    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.

  9. Auxin controls local cytokinin biosynthesis in the nodal stem in apical dominance.

    PubMed

    Tanaka, Mina; Takei, Kentaro; Kojima, Mikiko; Sakakibara, Hitoshi; Mori, Hitoshi

    2006-03-01

    In intact plants, the shoot apex grows predominantly and inhibits outgrowth of axillary buds. After decapitation of the shoot apex, outgrowth of axillary buds begins. This phenomenon is called an apical dominance. Although the involvement of auxin, which represses outgrowth of axillary buds, and cytokinin (CK), which promotes outgrowth of axillary buds, has been proposed, little is known about the underlying molecular mechanisms. In the present study, we demonstrated that auxin negatively regulates local CK biosynthesis in the nodal stem by controlling the expression level of the pea (Pisum sativum L.) gene adenosine phosphate-isopentenyltransferase (PsIPT), which encodes a key enzyme in CK biosynthesis. Before decapitation, PsIPT1 and PsIPT2 transcripts were undetectable; after decapitation, they were markedly induced in the nodal stem along with accumulation of CK. Expression of PsIPT was repressed by the application of indole-3-acetic acid (IAA). In excised nodal stem, PsIPT expression and CK levels also increased under IAA-free conditions. Furthermore, beta-glucuronidase expression, under the control of the PsIPT2 promoter region in transgenic Arabidopsis, was repressed by an IAA. Our results indicate that in apical dominance one role of auxin is to repress local biosynthesis of CK in the nodal stem and that, after decapitation, CKs, which are thought to be derived from the roots, are locally biosynthesized in the nodal stem rather than in the roots. PMID:16507092

  10. Temporal and spatial requirements for Nodal-induced anterior mesendoderm and mesoderm in anterior neurulation.

    PubMed

    Gonsar, Ngawang; Coughlin, Alicia; Clay-Wright, Jessica A; Borg, Bethanie R; Kindt, Lexy M; Liang, Jennifer O

    2016-01-01

    Zebrafish with defective Nodal signaling have a phenotype analogous to the fatal human birth defect anencephaly, which is caused by an open anterior neural tube. Previous work in our laboratory found that anterior open neural tube phenotypes in Nodal signaling mutants were caused by lack of mesendodermal/mesodermal tissues. Defects in these mutants are already apparent at neural plate stage, before the neuroepithelium starts to fold into a tube. Consistent with this, we found that the requirement for Nodal signaling maps to mid-late blastula stages. This timing correlates with the timing of prechordal plate mesendoderm and anterior mesoderm induction, suggesting these tissues act to promote neurulation. To further identify tissues important for neurulation, we took advantage of the variable phenotypes in Nodal signaling-deficient sqt mutant and Lefty1-overexpressing embryos. Statistical analysis indicated a strong, positive correlation between a closed neural tube and presence of several mesendoderm/mesoderm-derived tissues (hatching glands, cephalic paraxial mesoderm, notochord, and head muscles). However, the neural tube was closed in a subset of embryos that lacked any one of these tissues. This suggests that several types of Nodal-induced mesendodermal/mesodermal precursors are competent to promote neurulation. PMID:26528772

  11. Topological nodal-line fermions in spin-orbit metal PbTaSe2

    PubMed Central

    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

  12. Temporal and spatial requirements for Nodal-induced anterior mesendoderm and mesoderm in anterior neurulation.

    PubMed

    Gonsar, Ngawang; Coughlin, Alicia; Clay-Wright, Jessica A; Borg, Bethanie R; Kindt, Lexy M; Liang, Jennifer O

    2016-01-01

    Zebrafish with defective Nodal signaling have a phenotype analogous to the fatal human birth defect anencephaly, which is caused by an open anterior neural tube. Previous work in our laboratory found that anterior open neural tube phenotypes in Nodal signaling mutants were caused by lack of mesendodermal/mesodermal tissues. Defects in these mutants are already apparent at neural plate stage, before the neuroepithelium starts to fold into a tube. Consistent with this, we found that the requirement for Nodal signaling maps to mid-late blastula stages. This timing correlates with the timing of prechordal plate mesendoderm and anterior mesoderm induction, suggesting these tissues act to promote neurulation. To further identify tissues important for neurulation, we took advantage of the variable phenotypes in Nodal signaling-deficient sqt mutant and Lefty1-overexpressing embryos. Statistical analysis indicated a strong, positive correlation between a closed neural tube and presence of several mesendoderm/mesoderm-derived tissues (hatching glands, cephalic paraxial mesoderm, notochord, and head muscles). However, the neural tube was closed in a subset of embryos that lacked any one of these tissues. This suggests that several types of Nodal-induced mesendodermal/mesodermal precursors are competent to promote neurulation.

  13. Multiple component codes based generalized LDPC codes for high-speed optical transport.

    PubMed

    Djordjevic, Ivan B; Wang, Ting

    2014-07-14

    A class of generalized low-density parity-check (GLDPC) codes suitable for optical communications is proposed, which consists of multiple local codes. It is shown that Hamming, BCH, and Reed-Muller codes can be used as local codes, and that the maximum a posteriori probability (MAP) decoding of these local codes by Ashikhmin-Lytsin algorithm is feasible in terms of complexity and performance. We demonstrate that record coding gains can be obtained from properly designed GLDPC codes, derived from multiple component codes. We then show that several recently proposed classes of LDPC codes such as convolutional and spatially-coupled codes can be described using the concept of GLDPC coding, which indicates that the GLDPC coding can be used as a unified platform for advanced FEC enabling ultra-high speed optical transport. The proposed class of GLDPC codes is also suitable for code-rate adaption, to adjust the error correction strength depending on the optical channel conditions.

  14. Entrainment mapping in patients with sustained atrioventricular nodal reentrant tachycardia: insights into the sites of conduction slowing in the slow atrioventricular nodal pathway.

    PubMed

    Haines, D E; Nath, S; DiMarco, J P; Lobban, J H

    1997-10-01

    The inferoposterior region of the triangle of Koch is hypothesized to be the location of the atrial insertion of the slow atrioventricular (AV) nodal pathway. However, the actual site of conduction slowing in the slow AV nodal pathway is unknown. Entrainment mapping during AV nodal reentry can localize the reentrant pathway as follows: the AH interval measured from the mapping catheter = A'H (where A' is the exit site of the reentrant circuit) minus A'A (the conduction time from A' to the site of mapping); the SH interval during entrainment = SA' (the conduction time from stimulus into the reentry circuit) plus A'H. Thus, in all cases, the SH interval should be greater than or equal to the AH interval, and the deltaAH-SH should increase as distance and conduction time (SA' and A'A) from the reentry circuit increases. Fourteen patients with typical AV nodal reentry (cycle length 346 +/- 62 ms) and 1 with fast-slow (cycle length 430 ms) underwent activation and entrainment mapping from 8 to 12 sites in the triangle of Koch and coronary sinus. Pacing was performed at 2 to 3 mA above threshold, at a cycle length 10 ms shorter than tachycardia. A mapping site was defined as being in close proximity to the circuit if the deltaAH-SH was within 120% of the shortest 20th percentile deltaAH-SH value from all measured sites. In the 14 typical cases, 45 of 83 sites (54%) in the anatomic slow pathway region fulfilled criteria for close proximity to the reentry circuit compared with 13 of 50 sites (26%) outside of this region (p = 0.005). For these patients, the shortest SH interval measured from any entrainment site was 294 +/- 58 ms (89 +/- 10% of tachycardia cycle length, range 70% to 119%), indicating that the site of slow conduction in the slow pathway during AV nodal reentrant tachycardia was distal to all mapped sites. Thus, during typical AV nodal reentry, the "slow" pathway does not conduct slowly, and its insertion is located at or within the inferoposterior or

  15. Zebrafish Rab5 proteins and a role for Rab5ab in nodal signalling

    PubMed Central

    Kenyon, Emma J.; Campos, Isabel; Bull, James C.; Williams, P. Huw; Stemple, Derek L.; Clark, Matthew D.

    2015-01-01

    The RAB5 gene family is the best characterised of all human RAB families and is essential for in vitro homotypic fusion of early endosomes. In recent years, the disruption or activation of Rab5 family proteins has been used as a tool to understand growth factor signal transduction in whole animal systems such as Drosophila melanogaster and zebrafish. In this study we have examined the functions for four rab5 genes in zebrafish. Disruption of rab5ab expression by antisense morpholino oligonucleotide (MO) knockdown abolishes nodal signalling in early zebrafish embryos, whereas overexpression of rab5ab mRNA leads to ectopic expression of markers that are normally downstream of nodal signalling. By contrast MO disruption of other zebrafish rab5 genes shows little or no effect on expression of markers of dorsal organiser development. We conclude that rab5ab is essential for nodal signalling and organizer specification in the developing zebrafish embryo. PMID:25478908

  16. Zebrafish Rab5 proteins and a role for Rab5ab in nodal signalling.

    PubMed

    Kenyon, Emma J; Campos, Isabel; Bull, James C; Williams, P Huw; Stemple, Derek L; Clark, Matthew D

    2015-01-15

    The RAB5 gene family is the best characterised of all human RAB families and is essential for in vitro homotypic fusion of early endosomes. In recent years, the disruption or activation of Rab5 family proteins has been used as a tool to understand growth factor signal transduction in whole animal systems such as Drosophila melanogaster and zebrafish. In this study we have examined the functions for four rab5 genes in zebrafish. Disruption of rab5ab expression by antisense morpholino oligonucleotide (MO) knockdown abolishes nodal signalling in early zebrafish embryos, whereas overexpression of rab5ab mRNA leads to ectopic expression of markers that are normally downstream of nodal signalling. By contrast MO disruption of other zebrafish rab5 genes shows little or no effect on expression of markers of dorsal organiser development. We conclude that rab5ab is essential for nodal signalling and organizer specification in the developing zebrafish embryo.

  17. Molecular organization of the nodal region is not altered in spontaneously diabetic BB-Wistar rats.

    PubMed

    Brown, A A; Xu, T; Arroyo, E J; Levinson, S R; Brophy, P J; Peles, E; Scherer, S S

    2001-07-15

    We examined the organization of the molecular components of the nodal region in spontaneously diabetic BB-Wistar rats. Frozen sections and teased fibers from the sciatic nerves were immunostained for nodal (voltage-gated Na(+) channels, ankyrin(G), and ezrin), paranodal (contactin, Caspr, and neurofascin 155 kDa), and juxtaparanodal (Caspr2, the Shaker-type K(+) channels Kv1.1 and Kv1.2, and their associated subunit Kvbeta2) proteins. All of these proteins were properly localized in myelinated fibers from rats that had been diabetic for 15-44 days, compared to age-matched, nondiabetic animals. These results demonstrate that the axonal membrane is not reorganized, so nodal reorganization is not likely to be the cause of nerve conduction slowing in this animal model of acute diabetes. PMID:11438983

  18. Interaction of pupil offset and fifth-order nodal aberration field properties in rotationally symmetric telescopes.

    PubMed

    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.

  19. Melanocytes Affect Nodal Expression and Signaling in Melanoma Cells: A Lesson from Pediatric Large Congenital Melanocytic Nevi

    PubMed Central

    Margaryan, Naira V.; Gilgur, Alina; Seftor, Elisabeth A.; Purnell, Chad; Arva, Nicoleta C.; Gosain, Arun K.; Hendrix, Mary J. C.; Strizzi, Luigi

    2016-01-01

    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

  20. Assessment of Ultrasound Features Predicting Axillary Nodal Metastasis in Breast Cancer: The Impact of Cortical Thickness

    PubMed Central

    Stachs, A.; Thi, A. Tra-Ha; Dieterich, M.; Stubert, J.; Hartmann, S.; Glass, Ä.; Reimer, T.; Gerber, B.

    2015-01-01

    Purpose: To evaluate the accuracy of axillary ultrasound (AUS) in detecting nodal metastasis in patients with early-stage breast cancer and to identify AUS features with high predictive power. Materials and Methods: Prospective single-center preliminary study in 105 patients with a primary diagnosis of breast cancer and clinically negative axilla. AUS was performed using a 12 MHz linear-array transducer before ultrasound-guided needle biopsy. Nodal characteristics (shape, longitudinal-transverse [LT] axis ratio, margins, cortical thickness, hyperechoic hilum) were correlated with histopathological nodal status after SLNB or axillary lymph node dissection (ALND). Results: Nodal metastases were present in 42/105 patients (40.0%). Univariate analyses showed that absence of hyperechoic hilum, round shape, LT axis ratio<2, sharp margins and cortical thickness>3 mm were associated with lymph node metastasis. Multivariate logistic regression analysis revealed cortical thickness > 3 mm as an independent predictive parameter for nodal involvement. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 66.7, 74.6, 63.6, 77.0% and 71.4% respectively when cortical thickness > 3 mm was applied as the criterion for AUS positivity. Axillary tumor volume was low in patients with pT1/2 tumors and negative AUS, since only 3.2% of patients had > 2 metastatic lymph nodes. Conclusion: Cortical thickness>3 mm is a reliable predictor of nodal metastatic involvement. Negative AUS does not exclude lymph node metastases, but extensive axillary tumor volume is rare.

  1. Recent Advances in the Modeling of the Transport of Two-Plasmon-Decay Electrons in the 1-D Hydrodynamic Code LILAC

    NASA Astrophysics Data System (ADS)

    Delettrez, J. A.; Myatt, J. F.; Yaakobi, B.

    2015-11-01

    The modeling of the fast-electron transport in the 1-D hydrodynamic code LILAC was modified because of the addition of cross-beam-energy-transfer (CBET) in implosion simulations. Using the old fast-electron with source model CBET results in a shift of the peak of the hard x-ray (HXR) production from the end of the laser pulse, as observed in experiments, to earlier in the pulse. This is caused by a drop in the laser intensity of the quarter-critical surface from CBET interaction at lower densities. Data from simulations with the laser plasma simulation environment (LPSE) code will be used to modify the source algorithm in LILAC. In addition, the transport model in LILAC has been modified to include deviations from the straight-line algorithm and non-specular reflection at the sheath to take into account the scattering from collisions and magnetic fields in the corona. Simulation results will be compared with HXR emissions from both room-temperature plastic and cryogenic target experiments. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  2. Incidental Prophylactic Nodal Irradiation and Patterns of Nodal Relapse in Inoperable Early Stage NSCLC Patients Treated With SBRT: A Case-Matched Analysis

    SciTech Connect

    Lao, Louis; Hope, Andrew J.; Maganti, Manjula; Brade, Anthony; Bezjak, Andrea; Saibishkumar, Elantholi P.; Giuliani, Meredith; Sun, Alexander; Cho, B. C. John

    2014-09-01

    Purpose: Reported rates of non-small cell lung cancer (NSCLC) nodal failure following stereotactic body radiation therapy (SBRT) are lower than those reported in the surgical series when matched for stage. We hypothesized that this effect was due to incidental prophylactic nodal irradiation. Methods and Materials: A prospectively collected group of medically inoperable early stage NSCLC patients from 2004 to 2010 was used to identify cases with nodal relapses. Controls were matched to cases, 2:1, controlling for tumor volume (ie, same or greater) and tumor location (ie, same lobe). Reference (normalized to equivalent dose for 2-Gy fractions [EQD2]) point doses at the ipsilateral hilum and carina, demographic data, and clinical outcomes were extracted from the medical records. Univariate conditional logistical regression analyses were performed with variables of interest. Results: Cases and controls were well matched except for size. The controls, as expected, had larger gross tumor volumes (P=.02). The mean ipsilateral hilar doses were 9.6 Gy and 22.4 Gy for cases and controls, respectively (P=.014). The mean carinal doses were 7.0 Gy and 9.2 Gy, respectively (P=.13). Mediastinal nodal relapses, with and without ipsilateral hilar relapse, were associated with mean ipsilateral hilar doses of 3.6 Gy and 19.8 Gy, respectively (P=.01). The conditional density plot appears to demonstrate an inverse dose-effect relationship between ipsilateral hilar normalized total dose and risk of ipsilateral hilar relapse. Conclusions: Incidental hilar dose greater than 20 Gy is significantly associated with fewer ipsilateral hilar relapses in inoperable early stage NSCLC patients treated with SBRT.

  3. Advanced reactor physics methods for heterogeneous reactor cores

    NASA Astrophysics Data System (ADS)

    Thompson, Steven A.

    To maintain the economic viability of nuclear power the industry has begun to emphasize maximizing the efficiency and output of existing nuclear power plants by using longer fuel cycles, stretch power uprates, shorter outage lengths, mixed-oxide (MOX) fuel and more aggressive operating strategies. In order to accommodate these changes, while still satisfying the peaking factor and power envelope requirements necessary to maintain safe operation, more complexity in commercial core designs have been implemented, such as an increase in the number of sub-batches and an increase in the use of both discrete and integral burnable poisons. A consequence of the increased complexity of core designs, as well as the use of MOX fuel, is an increase in the neutronic heterogeneity of the core. Such heterogeneous cores introduce challenges for the current methods that are used for reactor analysis. New methods must be developed to address these deficiencies while still maintaining the computational efficiency of existing reactor analysis methods. In this thesis, advanced core design methodologies are developed to be able to adequately analyze the highly heterogeneous core designs which are currently in use in commercial power reactors. These methodological improvements are being pursued with the goal of not sacrificing the computational efficiency which core designers require. More specifically, the PSU nodal code NEM is being updated to include an SP3 solution option, an advanced transverse leakage option, and a semi-analytical NEM solution option.

  4. Asymmetric and node-specific nodal expression patterns are controlled by two distinct cis-acting regulatory elements

    PubMed Central

    Norris, Dominic P.; Robertson, Elizabeth J.

    1999-01-01

    The TGFβ-related molecule Nodal is required for establishment of the anterior–posterior (A–P) and left–right (L-R) body axes of the vertebrate embryo. In mouse, several discrete sites of nodal activity closely correlate with its highly dynamic expression domains. nodal function in the posterior epiblast promotes primitive streak formation, whereas transient nodal expression in the extraembryonic visceral endoderm is essential for patterning the rostral central nervous system. Asymmetric nodal expression in the developing node and at later stages in left lateral plate mesoderm has been implicated as a key regulator of L-R axis determination. We have analyzed the cis-regulatory elements controlling nodal expression domains during early development. We show that the regulatory sequences conferring node-specific expression are contained in an upstream region of the locus, whereas early expression in the endoderm and epiblast and asymmetric expression at later stages on the left side of the body axis are controlled by a 600-bp intronic enhancer. Targeted deletion of a 100-bp subregion of this intronic enhancer eliminates nodal expression in the early epiblast and visceral endoderm and disrupts asymmetric expression in the node and lateral plate mesoderm. Thus, developmentally regulated nodal expression at distinct tissue sites during A–P and L-R axis formation is potentially controlled by common transcriptional activators. PMID:10385626

  5. Nodal Quasiparticle Meltdown in Ultra-High Resolution Pump-Probe Angle-Resolved Photoemission

    SciTech Connect

    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

  6. Seals Code Development Workshop

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C. (Compiler); Liang, Anita D. (Compiler)

    1996-01-01

    Seals Workshop of 1995 industrial code (INDSEAL) release include ICYL, GCYLT, IFACE, GFACE, SPIRALG, SPIRALI, DYSEAL, and KTK. The scientific code (SCISEAL) release includes conjugate heat transfer and multidomain with rotordynamic capability. Several seals and bearings codes (e.g., HYDROFLEX, HYDROTRAN, HYDROB3D, FLOWCON1, FLOWCON2) are presented and results compared. Current computational and experimental emphasis includes multiple connected cavity flows with goals of reducing parasitic losses and gas ingestion. Labyrinth seals continue to play a significant role in sealing with face, honeycomb, and new sealing concepts under investigation for advanced engine concepts in view of strict environmental constraints. The clean sheet approach to engine design is advocated with program directions and anticipated percentage SFC reductions cited. Future activities center on engine applications with coupled seal/power/secondary flow streams.

  7. Comparing nodal versus bony metastatic spread using tumour phylogenies

    PubMed Central

    Mangiola, Stefano; Hong, Matthew K. H.; Cmero, Marek; Kurganovs, Natalie; Ryan, Andrew; Costello, Anthony J.; Corcoran, Niall M.; Macintyre, Geoff; Hovens, Christopher M.

    2016-01-01

    The role of lymph node metastases in distant prostate cancer dissemination and lethality is ill defined. Patients with metastases restricted to lymph nodes have a better prognosis than those with distant metastatic spread, suggesting the possibility of distinct aetiologies. To explore this, we traced patterns of cancer dissemination using tumour phylogenies inferred from genome-wide copy-number profiling of 48 samples across 3 patients with lymph node metastatic disease and 3 patients with osseous metastatic disease. Our results show that metastatic cells in regional lymph nodes originate from evolutionary advanced extraprostatic tumour cells rather than less advanced central tumour cell populations. In contrast, osseous metastases do not exhibit such a constrained developmental lineage, arising from either intra or extraprostatic tumour cell populations, at early and late stages in the evolution of the primary. Collectively, this comparison suggests that lymph node metastases may not be an intermediate developmental step for distant osseous metastases, but rather represent a distinct metastatic lineage. PMID:27653089

  8. The general theory of convolutional codes

    NASA Technical Reports Server (NTRS)

    Mceliece, R. J.; Stanley, R. P.

    1993-01-01

    This article presents a self-contained introduction to the algebraic theory of convolutional codes. This introduction is partly a tutorial, but at the same time contains a number of new results which will prove useful for designers of advanced telecommunication systems. Among the new concepts introduced here are the Hilbert series for a convolutional code and the class of compact codes.

  9. Multiplicity of positive and nodal solutions for scalar field equations

    NASA Astrophysics Data System (ADS)

    Cerami, Giovanna; Molle, Riccardo; Passaseo, Donato

    2014-11-01

    In this paper the question of finding infinitely many solutions to the problem -Δu+a(x)u=|u, in RN, u∈H1(RN), is considered when N≥2, p∈(2,2N/(N-2)), and the potential a(x) is a positive function which is not required to enjoy symmetry properties. Assuming that a(x) satisfies a suitable “slow decay at infinity” condition and, moreover, that its graph has some “dips”, we prove that the problem admits either infinitely many nodal solutions or infinitely many constant sign solutions. The proof method is purely variational and allows to describe the shape of the solutions. a(x)→a∞>0 as|x|→∞, a(x)≥a0>0 ∀x∈RN, a∈LlocN/2(RN), ∃ηbar∈(0,√{a∞}):lim|x|→∞ ⁡(a(x)-a∞)e=∞ be satisfied.Then there exists a positive constant,A=A(N,ηbar,a0,a∞)∈R, such that, when|a(x)-a∞|N/2,loc:=supy∈RN ⁡|a(x)-a∞|L(B1(y))The above result (see also the subsequent [3] for a different proof and more general nonlinearities) is the starting point of our work; some comments and questions come naturally looking at its statement. Indeed, assumptions (h1)-(h3) are standard and very mild, moreover, the slow decay condition (h4) is basic and it is the deep motivation for the success in obtaining “multibump” solutions. The solutions are found by a max-min argument on the action functional I restricted to special classes of multibump functions

  10. 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).

  11. [The Nodal regulated dusp4 inhibits mesendoderm formation during zebrafish gastrulation].

    PubMed

    Liu, Zhao-Ting; Wei, Shi; Wang, Qiang

    2012-09-01

    MAP kinase phosphatase-2 (MKP-2/DUSP4), a dual specificity protein phosphatase with tyrosine/serine/ threonine phosphatase activity, is associated with cellular proliferation and differentiation, but its functions during embryo development are unclear. To study the developmental function of dusp4, we first examined the spatiotemporal expression pattern of this gene during zebrafish embryonic development by whole mount in situ hybridization. We found that dusp4 was maternally expressed since its transcripts were present from the one-cell to the 256-cell stages. At early gastrulation stages, dusp4 transcripts specifically distributed at margin region, where the mesendodermal cells were located. Further-more, Nodal signal was crucial for dusp4 expression. The expression of dusp4 was obviously increased in Nodal ligand overexpressed embryos, while its expression was almost lost in the Nodal signal-deficient MZoep mutants. In addition, dusp4 MO was also designed to knock down its expression in embryos. The mesendoderm formation was significantly in-creased in dusp4 morphants, but not obviously changed in dusp4 overexpressed embryos, suggesting that dusp4 is necessary, but not sufficient for the inhibitory of mesendoderm induction. Thus, our results indicate that Nodal regulated dusp4 plays a repressive role in mesendoderm induction. PMID:23017456

  12. Photoacoustic intra-operative nodal staging using clinically approved superparamagnetic iron oxide nanoparticles

    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.

  13. 47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... authorized only as a part of an integrated communication system wherein 10.6 GHz DEMS User Stations... 47 Telecommunication 5 2013-10-01 2013-10-01 false Digital Electronic Message Service Nodal Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)...

  14. 47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... authorized only as a part of an integrated communication system wherein 10.6 GHz DEMS User Stations... 47 Telecommunication 5 2012-10-01 2012-10-01 false Digital Electronic Message Service Nodal Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)...

  15. 47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... authorized only as a part of an integrated communication system wherein 10.6 GHz DEMS User Stations... 47 Telecommunication 5 2014-10-01 2014-10-01 false Digital Electronic Message Service Nodal Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)...

  16. 47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... authorized only as a part of an integrated communication system wherein 10.6 GHz DEMS User Stations... 47 Telecommunication 5 2011-10-01 2011-10-01 false Digital Electronic Message Service Nodal Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)...

  17. 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.

  18. A nodal spectral stiffness matrix for the finite-element method

    NASA Astrophysics Data System (ADS)

    Bittencourt, Marco L.; Vazquez, Thais G.

    2008-12-01

    In this paper, shape functions are proposed for the spectral finite-element method aiming to finding a nodal spectral stiffness matrix. The proposed shape functions obtain a nearly diagonal 1D stiffness matrix with better conditioning than using the Lagrange and Jacobi bases.

  19. Nodal Analysis Optimization Based on the Use of Virtual Current Sources: A Powerful New Pedagogical Method

    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…

  20. Analysis of nodal aberration properties in off-axis freeform system design.

    PubMed

    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. PMID:27557003

  1. Nodal signaling regulates endodermal cell motility and actin dynamics via Rac1 and Prex1

    PubMed Central

    Housley, Michael P.; Weiner, Orion D.

    2012-01-01

    Embryo morphogenesis is driven by dynamic cell behaviors, including migration, that are coordinated with fate specification and differentiation, but how such coordination is achieved remains poorly understood. During zebrafish gastrulation, endodermal cells sequentially exhibit first random, nonpersistent migration followed by oriented, persistent migration and finally collective migration. Using a novel transgenic line that labels the endodermal actin cytoskeleton, we found that these stage-dependent changes in migratory behavior correlated with changes in actin dynamics. The dynamic actin and random motility exhibited during early gastrulation were dependent on both Nodal and Rac1 signaling. We further identified the Rac-specific guanine nucleotide exchange factor Prex1 as a Nodal target and showed that it mediated Nodal-dependent random motility. Reducing Rac1 activity in endodermal cells caused them to bypass the random migration phase and aberrantly contribute to mesodermal tissues. Together, our results reveal a novel role for Nodal signaling in regulating actin dynamics and migration behavior, which are crucial for endodermal morphogenesis and cell fate decisions. PMID:22945937

  2. Analysis of nodal aberration properties in off-axis freeform system design.

    PubMed

    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.

  3. Sensitivity derivatives and optimization of nodal point locations for vibration reduction

    NASA Technical Reports Server (NTRS)

    Pritchard, Jocelyn I.; Adelman, Howard M.; Haftka, Raphael T.

    1987-01-01

    A method is developed for sensitivity analysis and optimization of nodal point locations in connection with vibration reduction. A straightforward derivation of the expression for the derivative of nodal locations is given, and the role of the derivative in assessing design trends is demonstrated. An optimization process is developed which uses added lumped masses on the structure as design variables to move the node to a preselected location; for example, where low response amplitude is required or to a point which makes the mode shape nearly orthogonal to the force distribution, thereby minimizing the generalized force. The optimization formulation leads to values for added masses that adjust a nodal location while minimizing the total amount of added mass required to do so. As an example, the node of the second mode of a cantilever box beam is relocated to coincide with the centroid of a prescribed force distribution, thereby reducing the generalized force substantially without adding excessive mass. A comparison with an optimization formulation that directly minimizes the generalized force indicates that nodal placement gives essentially a minimum generalized force when the node is appropriately placed.

  4. Senstitivty analysis and optimization of nodal point placement for vibration reduction

    NASA Technical Reports Server (NTRS)

    Pritchard, J. I.; Adelman, H. M.; Haftka, R. T.

    1986-01-01

    A method is developed for sensitivity analysis and optimization of nodal point locations in connection with vibration reduction. A straightforward derivation of the expression for the derivative of nodal locations is given, and the role of the derivative in assessing design trends is demonstrated. An optimization process is developed which uses added lumped masses on the structure as design variables to move the node to a preselected location - for example, where low response amplitude is required or to a point which makes the mode shape nearly orthogonal to the force distribution, thereby minimizing the generalized force. The optimization formulation leads to values for added masses that adjust a nodal location while minimizing the total amount of added mass required to do so. As an example, the node of the second mode of a cantilever box beam is relocated to coincide with the centroid of a prescribed force distribution, thereby reducing the generalized force substantially without adding excessive mass. A comparison with an optimization formulation that directly minimizes the generalized force indicates that nodal placement gives essentially a minimum generalized force when the node is appropriately placed.

  5. A difference-equation formalism for the nodal domains of separable billiards

    NASA Astrophysics Data System (ADS)

    Manjunath, Naren; Samajdar, Rhine; Jain, Sudhir R.

    2016-09-01

    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.

  6. Radiation therapy for carcinoma of the hypopharynx with special reference to nodal control

    SciTech Connect

    Teshima, T.; Chatani, M.; Inoue, T.; Miyahara, H.; Sato, T.

    1988-05-01

    From October 1977 through December 1983, 61 patients with carcinoma of the hypopharynx were treated with radiation therapy (RT) and surgery or with RT alone. Five-year survival rates by N-stage, according to the TNM classification by UICC (1978), were 52% for N0 cases, 23% for N1, and 17% for N2-3 (N1 vs. N2-3, not significant). For N1-3 cases, corresponding figures by level of cervical nodal involvement by UICC (1978) were 29% for level 3 cases, 15% for level 2, and 8% for level 4 (level 3 vs. level 4, p less than 0.04). Therefore, the level of cervical nodal involvement was a more useful prognosticator for patients with nodal metastasis than the N-stage. Effective nodal control for patients with clinically positive nodes (N1-3) was obtained with a combination of neck node dissection and RT of 50 Gy or more. For N0 cases, elective RT of 50 Gy or more, encompassing an adequate field, was required.

  7. Topological nodal-line semimetals in alkaline-earth stannides, germanides, and silicides

    NASA Astrophysics Data System (ADS)

    Huang, Huaqing; Liu, Jianpeng; Vanderbilt, David; Duan, Wenhui

    2016-05-01

    Based on first-principles calculations and an effective Hamiltonian analysis, we systematically investigate the electronic and topological properties of alkaline-earth compounds A X2 (A =Ca , Sr, Ba; X =Si , Ge, Sn). Taking BaSn2 as an example, we find that when spin-orbit coupling is ignored, these materials are three-dimensional topological nodal-line semimetals characterized by a snakelike nodal loop in three-dimensional momentum space. Drumheadlike surface states emerge either inside or outside the loop circle on the (001) surface depending on surface termination, while complicated double-drumhead-like surface states appear on the (010) surface. When spin-orbit coupling is included, the nodal line is gapped and the system becomes a topological insulator with Z2 topological invariants (1;001). Since spin-orbit coupling effects are weak in light elements, the nodal-line semimetal phase is expected to be achievable in some alkaline-earth germanides and silicides.

  8. Speech coding

    SciTech Connect

    Ravishankar, C., Hughes Network Systems, Germantown, MD

    1998-05-08

    Speech is the predominant means of communication between human beings and since the invention of the telephone by Alexander Graham Bell in 1876, speech services have remained to be the core service in almost all telecommunication systems. Original analog methods of telephony had the disadvantage of speech signal getting corrupted by noise, cross-talk and distortion Long haul transmissions which use repeaters to compensate for the loss in signal strength on transmission links also increase the associated noise and distortion. On the other hand digital transmission is relatively immune to noise, cross-talk and distortion primarily because of the capability to faithfully regenerate digital signal at each repeater purely based on a binary decision. Hence end-to-end performance of the digital link essentially becomes independent of the length and operating frequency bands of the link Hence from a transmission point of view digital transmission has been the preferred approach due to its higher immunity to noise. The need to carry digital speech became extremely important from a service provision point of view as well. Modem requirements have introduced the need for robust, flexible and secure services that can carry a multitude of signal types (such as voice, data and video) without a fundamental change in infrastructure. Such a requirement could not have been easily met without the advent of digital transmission systems, thereby requiring speech to be coded digitally. The term Speech Coding is often referred to techniques that represent or code speech signals either directly as a waveform or as a set of parameters by analyzing the speech signal. In either case, the codes are transmitted to the distant end where speech is reconstructed or synthesized using the received set of codes. A more generic term that is applicable to these techniques that is often interchangeably used with speech coding is the term voice coding. This term is more generic in the sense that the

  9. Mammographic Density and Prediction of Nodal Status in Breast Cancer Patients.

    PubMed

    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

    2013-02-01

    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.

  10. Concordance of studies for nodal staging is prognostic for worse survival in esophageal cancer.

    PubMed

    Dhupar, R; Correa, A M; Ajani, J; Betancourt, S; Mehran, R J; Swisher, S G; Hofstetter, W L

    2014-01-01

    Pretreatment clinical staging in esophageal cancer influences prognosis and treatment strategy. Current staging strategies utilize multiple imaging modalities, and often the results are contradictory. No studies have examined the implications of concordance of computed tomography (CT), positron emission tomography (PET), and endoscopic ultrasound (EUS) when used for the evaluation of nodal disease. The objective of this study was to determine if concordance of CT, PET, or EUS for nodal disease predicts worse overall survival. We reviewed 615 esophageal cancer patients with pretreatment CT, PET, and EUS that underwent esophagectomy for survival outcomes based on concordance of studies for nodal disease. Concordant N+ is defined as two or three studies positive for nodal disease; non-concordant N+ is defined as only one positive study. Node-positive disease by any study predicted shorter survival than node-negative disease (42% vs. 73% 5-year survival; P<0.001). Additionally, non-concordant N+ patients had shorter survival than N- patients (52% vs. 73% 5-year survival; P<0.001). Concordant N+ patients had shorter survival than non-concordant N+ patients (38- vs. 61-month median survival; P=0.017). There were no statistically significant differences in survival based on specific combinations of studies. When PET was disregarded, patients with both CT+ and EUS+ had shorter survival than patients with either CT+ or EUS+ (39- vs. 58-month median survival; P=0.029). Pretreatment CT, PET, or EUS concordance for node-positive disease predicts shorter overall survival in patients that undergo esophagectomy for esophageal cancer. Predicting survival in esophageal cancer should consider the synergistic capabilities of CT, PET, and EUS in evaluating nodal status.

  11. Radiotherapy for Esthesioneuroblastoma: Is Elective Nodal Irradiation Warranted in the Multimodality Treatment Approach?

    SciTech Connect

    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.

  12. Laser catheter-induced atrioventricular nodal delays and atrioventricular block in dogs: acute and chronic observations.

    PubMed

    Narula, O S; Boveja, B K; Cohen, D M; Narula, J T; Tarjan, P P

    1985-02-01

    Selective modification of atrioventricular (AV) nodal conduction, that is, induction of varying degrees of AV nodal delays or block (second or third degree), or both, was achieved with a pervenous laser catheter technique. In six adult mongrel dogs anesthetized with pentobarbital (Nembutal), 5F leads were placed through femoral and external jugular veins and placed into the right atrium and His bundle region. Through another femoral vein, a 200 micron optical fiber was inserted by way of a 7F catheter with a preformed curved tip. Guided by fluoroscopy and His bundle electrograms, the fiber's tip was positioned in the AV nodal region. After autonomic blockade was achieved with intravenous propranolol (5 mg) and atropine (1 mg), AV conduction was analyzed. An argon laser delivered 3 to 4 watts into the fiber in bursts of 10 seconds' duration until the desired degree of AV nodal delay or block (second or third degree) was manifested. Monitoring of His bundle electrograms was continued for 2 hours. Four weekly serial electrocardiograms were recorded, after which electrophysiologic studies were repeated. Acute post-lasing studies showed that: in all six dogs, the mean PR interval was prolonged from 116 ms (range 100 to 135) to 153 ms (range 120 to 185), with the prolongation being caused exclusively by AH lengthening from 68 ms (range 50 to 90) to 105 ms (range 65 to 140); the mean effective refractory period of the AV node increased from less than 185 ms (range less than 150 to less than 200) to 215 ms (range 190 to 280); and the mean atrial pacing cycle length, at which second degree AV nodal block was manifested, increased from 210 ms (range 160 to 260) to 261 ms (range 205 to 320).(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Clinical nodal staging scores for prostate cancer: a proposal for preoperative risk assessment

    PubMed Central

    Kluth, L A; Abdollah, F; Xylinas, E; Rieken, M; Fajkovic, H; Seitz, C; Sun, M; Karakiewicz, P I; Schramek, P; Herman, M P; Becker, A; Hansen, J; Ehdaie, B; Loidl, W; Pummer, K; Lee, R K; Lotan, Y; Scherr, D S; Seiler, D; Ahyai, S A; Chun, F K-H; Graefen, M; Tewari, A; Nonis, A; Bachmann, A; Montorsi, F; Gönen, M; Briganti, A; Shariat, S F

    2014-01-01

    Background: Pelvic lymph node dissection in patients undergoing radical prostatectomy for clinically localised prostate cancer is not without morbidity and its therapeutical benefit is still a matter of debate. The objective of this study was to develop a model that allows preoperative determination of the minimum number of lymph nodes needed to be removed at radical prostatectomy to ensure true nodal status. Methods: We analysed data from 4770 patients treated with radical prostatectomy and pelvic lymph node dissection between 2000 and 2011 from eight academic centres. For external validation of our model, we used data from a cohort of 3595 patients who underwent an anatomically defined extended pelvic lymph node dissection. We estimated the sensitivity of pathological nodal staging using a beta-binomial model and developed a novel clinical (preoperative) nodal staging score (cNSS), which represents the probability that a patient has lymph node metastasis as a function of the number of examined nodes. Results: In the development and validation cohorts, the probability of missing a positive lymph node decreases with increase in the number of nodes examined. A 90% cNSS can be achieved in the development and validation cohorts by examining 1–6 nodes in cT1 and 6–8 nodes in cT2 tumours. With 11 nodes examined, patients in the development and validation cohorts achieved a cNSS of 90% and 80% with cT3 tumours, respectively. Conclusions: Pelvic lymph node dissection is the only reliable technique to ensure accurate nodal staging in patients treated with radical prostatectomy for clinically localised prostate cancer. The minimum number of examined lymph nodes needed for accurate nodal staging may be predictable, being strongly dependent on prostate cancer characteristics at diagnosis. PMID:25003663

  14. Modular Code and Data System for Fast Reactor Neutronics Analyses

    2008-06-30

    Version 00. The European Reactor ANalysis Optimized calculation System, ERANOS, has been developed and validated with the aim of providing a suitable basis for reliable neutronic calculations of current as well as advanced fast reactor cores. It consists of data libraries, deterministic codes and calculation procedures which have been developed within the European Collaboration on Fast Reactors over the past 20 years or so, in order to answer the needs of both industrial and R&Dmore » organisations. The whole system counts roughly 250 functions and 3000 subroutines totalling 450000 lines of FORTRAN-77 and ESOPE instructions. ERANOS is written using the ALOS software which requires only standard FORTRAN compilers and includes advanced programming features. A modular structure was adopted for easier evolution and incorporation of new functionalities. Blocks of data (SETs) can be created or used by the modules themselves or by the user via the LU control language. Programming, and dynamic memory allocation, are performed by means of the ESOPE language. External temporary storage and permanent storage capabilities are provided by the GEMAT and ARCHIVE functions, respectively. ESOPE, LU, GEMAT and ARCHIVE are all part of the ALOS software. This modular structure allows different modules to be linked together in procedures corresponding to recommended calculation routes ranging from fast-running and moderately-accurate 'routine' procedures to slow-running but highly-accurate 'reference' procedures. The main contents of the ERANOS-2.0 package are: nuclear data libraries (multigroup cross-sections from the JEF-2.2 evaluated nuclear data file, and other specific data files), a cell and lattice code (ECCO), reactor flux solvers (diffusion, Sn transport, nodal variational transport), a burn-up module, various processing modules (material and neutron balance, breeding gains,...), tools related to perturbation theory and sensitivity analysis, core follow-up modules (connected

  15. Modern Radiation Therapy for Nodal Non-Hodgkin Lymphoma—Target Definition and Dose Guidelines From the International Lymphoma Radiation Oncology Group

    SciTech Connect

    Illidge, Tim; Specht, Lena; Yahalom, Joachim; Aleman, Berthe; Berthelsen, Anne Kiil; Constine, Louis; Dabaja, Bouthaina; Dharmarajan, Kavita; Ng, Andrea; Ricardi, Umberto; Wirth, Andrew

    2014-05-01

    Radiation therapy (RT) is the most effective single modality for local control of non-Hodgkin lymphoma (NHL) and is an important component of therapy for many patients. Many of the historic concepts of dose and volume have recently been challenged by the advent of modern imaging and RT planning tools. The International Lymphoma Radiation Oncology Group (ILROG) has developed these guidelines after multinational meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the ILROG steering committee on the use of RT in NHL in the modern era. The roles of reduced volume and reduced doses are addressed, integrating modern imaging with 3-dimensional planning and advanced techniques of RT delivery. In the modern era, in which combined-modality treatment with systemic therapy is appropriate, the previously applied extended-field and involved-field RT techniques that targeted nodal regions have now been replaced by limiting the RT to smaller volumes based solely on detectable nodal involvement at presentation. A new concept, involved-site RT, defines the clinical target volume. For indolent NHL, often treated with RT alone, larger fields should be considered. Newer treatment techniques, including intensity modulated RT, breath holding, image guided RT, and 4-dimensional imaging, should be implemented, and their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control.

  16. QR Codes

    ERIC Educational Resources Information Center

    Lai, Hsin-Chih; Chang, Chun-Yen; Li, Wen-Shiane; Fan, Yu-Lin; Wu, Ying-Tien

    2013-01-01

    This study presents an m-learning method that incorporates Integrated Quick Response (QR) codes. This learning method not only achieves the objectives of outdoor education, but it also increases applications of Cognitive Theory of Multimedia Learning (CTML) (Mayer, 2001) in m-learning for practical use in a diverse range of outdoor locations. When…

  17. Nodal signaling is required for mesodermal and ventral but not for dorsal fates in the indirect developing hemichordate, Ptychodera flava.

    PubMed

    Röttinger, Eric; DuBuc, Timothy Q; Amiel, Aldine R; Martindale, Mark Q

    2015-01-01

    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

  18. Nodal signaling is required for mesodermal and ventral but not for dorsal fates in the indirect developing hemichordate, Ptychodera flava.

    PubMed

    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.

  19. Nodal signaling is required for mesodermal and ventral but not for dorsal fates in the indirect developing hemichordate, Ptychodera flava

    PubMed Central

    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

  20. Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis

    PubMed Central

    Saucedo-García, Mariana; Gavilanes-Ruíz, Marina; Arce-Cervantes, Oscar

    2015-01-01

    Due to their sessile condition, plants have developed sensitive, fast, and effective ways to contend with environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate, and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases and non-protein, smaller molecules, such as long-chain bases, phosphatidic acid, and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very diverse stimuli and evoke very different responses. These pleiotropic effects may be explained by the potentiality that every one of these four mediators can be expressed from different sources, cellular location, temporality, or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses. PMID:25763001

  1. Nuclear Energy -- Knowledge Base for Advanced Modeling and Simulation (NE-KAMS) Code Verification and Validation Data Standards and Requirements: Fluid Dynamics Version 1.0

    SciTech Connect

    Greg Weirs; Hyung Lee

    2011-09-01

    V&V and UQ are the primary means to assess the accuracy and reliability of M&S and, hence, to establish confidence in M&S. Though other industries are establishing standards and requirements for the performance of V&V and UQ, at present, the nuclear industry has not established such standards or requirements. However, the nuclear industry is beginning to recognize that such standards are needed and that the resources needed to support V&V and UQ will be very significant. In fact, no single organization has sufficient resources or expertise required to organize, conduct and maintain a comprehensive V&V and UQ program. What is needed is a systematic and standardized approach to establish and provide V&V and UQ resources at a national or even international level, with a consortium of partners from government, academia and industry. Specifically, what is needed is a structured and cost-effective knowledge base that collects, evaluates and stores verification and validation data, and shows how it can be used to perform V&V and UQ, leveraging collaboration and sharing of resources to support existing engineering and licensing procedures as well as science-based V&V and UQ processes. The Nuclear Energy Knowledge base for Advanced Modeling and Simulation (NE-KAMS) is being developed at the Idaho National Laboratory in conjunction with Bettis Laboratory, Sandia National Laboratories, Argonne National Laboratory, Utah State University and others with the objective of establishing a comprehensive and web-accessible knowledge base to provide V&V and UQ resources for M&S for nuclear reactor design, analysis and licensing. The knowledge base will serve as an important resource for technical exchange and collaboration that will enable credible and reliable computational models and simulations for application to nuclear power. NE-KAMS will serve as a valuable resource for the nuclear industry, academia, the national laboratories, the U.S. Nuclear Regulatory Commission (NRC) and

  2. The Redox Code

    PubMed Central

    Jones, Dean P.

    2015-01-01

    Abstract Significance: The redox code is a set of principles that defines the positioning of the nicotinamide adenine dinucleotide (NAD, NADP) and thiol/disulfide and other redox systems as well as the thiol redox proteome in space and time in biological systems. The code is richly elaborated in an oxygen-dependent life, where activation/deactivation cycles involving O2 and H2O2 contribute to spatiotemporal organization for differentiation, development, and adaptation to the environment. Disruption of this organizational structure during oxidative stress represents a fundamental mechanism in system failure and disease. Recent Advances: Methodology in assessing components of the redox code under physiological conditions has progressed, permitting insight into spatiotemporal organization and allowing for identification of redox partners in redox proteomics and redox metabolomics. Critical Issues: Complexity of redox networks and redox regulation is being revealed step by step, yet much still needs to be learned. Future Directions: Detailed knowledge of the molecular patterns generated from the principles of the redox code under defined physiological or pathological conditions in cells and organs will contribute to understanding the redox component in health and disease. Ultimately, there will be a scientific basis to a modern redox medicine. Antioxid. Redox Signal. 23, 734–746. PMID:25891126

  3. An amphioxus nodal gene (AmphiNodal) with early symmetrical expression in the organizer and mesoderm and later asymmetrical expression associated with left-right axis formation

    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.

  4. Contralateral axillary nodal involvement from invasive breast cancer.

    PubMed

    Kiluk, John V; Prowler, Vanessa; Lee, M Catherine; Khakpour, Nazanin; Laronga, Christine; Cox, Charles E

    2014-06-01

    Metastatic breast cancer to the contralateral axilla (CAM) is defined as stage IV disease. We postulate that CAM represents an extension of local-regional disease rather than distant metastasis and may have a better outcome. A single-institution, retrospective review of breast cancer cases from January 2005 and May 2011 was performed to identify cases with CAM. Eligibility for the study included unilateral primary breast cancer at presentation with synchronous/metachronous documented CAM without a documented primary invasive breast cancer within the contralateral breast by surgery or MRI. Clinicopathologic data was recorded for these patients (pts). Thirteen pts were identified. 12/13 (92%) pts presented with a locally advanced breast tumor or an ipsilateral in-breast recurrence. 10/13 (77%) pts had documented dermal involvement of tumor either at initial presentation or local recurrence. CAM occurred synchronously with the initial primary tumor (5 pts, 38%), concomitant with a local recurrence (5 pts, 38%), metachronously with the initial tumor (1 pt, 8%), and metachronously with a local recurrence (2 pts, 15%). Three patients had other distant disease at presentation. Of the other 10 pts, seven developed distant disease with a mean follow up of 3.6 years (range 0.3-7.6 years). Three pts have no evidence of disease at a mean follow up of 5.8 years (range 1.5-8.2). CAM may have different prognostic implications than other distant metastases and may occur through dermal lymphatic spread. Further study is warranted on the prognosis and management of these challenging and rare cases. PMID:24709584

  5. 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.

  6. The General-Use Nodal Network Solver (GUNNS) Modeling Package for Space Vehicle Flow System Simulation

    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.

  7. 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.

  8. Normal State Spectral Lineshapes of Nodal Quasiparticles in Single Layer Bi2201 Superconductor

    SciTech Connect

    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.

  9. Cryopreservation of Passiflora pohlii nodal segments and assessment of genetic stability of regenerated plants.

    PubMed

    Merhy, T S M; Vianna, M G; Garcia, R O; Pacheco, G; Mansur, E

    2014-01-01

    Passiflora pohlii is a wild species native to Brazil, with a potential agronomic interest due to its tolerance to soil-borne pathogens that cause damage to the passion fruit culture, and could be used in breeding. Because this species occurs in impacted regions, the goal of this study was the development of in vitro conservation strategies, using nodal segments from axenic plants. Encapsulation-vitrification and vitrification techniques were tested for cryopreservation of nodal segments. The highest recovery (65%) was obtained with the vitrification technique using treatment with the PVS3 vitrification solution from 30 to 120 min. Post-rewarming recovery was achieved on MSM medium supplemented with 30.8 μM BAP with incubation in the dark for 30 days before transfer in the presence of light. No differences were detected between control and cryopreserved materials as assayed by RAPD and ISSR. PMID:24997838

  10. Coherence Effects of Caroli-de Gennes-Matricon Modes in Nodal Topological Superconductors

    NASA Astrophysics Data System (ADS)

    Tsutsumi, Yasumasa; Kato, Yusuke

    2016-05-01

    Coherence effects by the impurity scattering of Caroli-de Gennes-Matricon (CdGM) modes in a vortex for nodal topological superconductors have been studied. The coherence effects reflect a topological number defined on a particular momentum space avoiding the superconducting gap nodes. First, we analytically derived the eigenvalue and eigenfunction of the CdGM modes, including the zero-energy modes, in a nodal topological superconducting state without impurities, where we focused on a possible superconducting state of UPt3 as an example. Then, we studied impurity effects on the CdGM modes by introducing the impurity self-energy, which are dominated by the coherence factor depending on the eigenfunction of the CdGM modes. For the zero-energy CdGM modes, the coherence factor vanishes in a certain momentum range, which is guaranteed by topological invariance characterized by the one-dimensional winding number.

  11. Nodal collocation approximation for the multidimensional PL equations applied to transport source problems

    SciTech Connect

    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)

  12. Three-Dimensional Conformal Radiation Therapy for Esophageal Squamous Cell Carcinoma: Is Elective Nodal Irradiation Necessary?

    SciTech Connect

    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.

  13. Salvage therapy of small volume prostate cancer nodal failures: a review of the literature.

    PubMed

    De Bari, Berardino; Alongi, Filippo; Buglione, Michela; Campostrini, Franco; Briganti, Alberto; Berardi, Genoveffa; Petralia, Giuseppe; Bellomi, Massimo; Chiti, Arturo; Fodor, Andrei; Suardi, Nazareno; Cozzarini, Cesare; Nadia, Di Muzio; Scorsetti, Marta; Orecchia, Roberto; Montorsi, Francesco; Bertoni, Filippo; Magrini, Stefano Maria; Jereczek-Fossa, Barbara Alicja

    2014-04-01

    New imaging modalities may be useful to identify prostate cancer patients with small volume, limited nodal relapse ("oligo-recurrent") potentially amenable to local treatments (radiotherapy, surgery) with the aim of long-term control of the disease, even in a condition traditionally considered prognostically unfavorable. This report reviews the new diagnostic tools and the main published data about the role of surgery and radiation therapy in this particular subgroup of patients.

  14. Sentinel Node Identification Rate and Nodal Involvement in the EORTC 10981-22023 AMAROS Trial

    PubMed Central

    Meijnen, Philip; van Tienhoven, Geertjan; van de Velde, Cornelis J. H.; Mansel, Robert E.; Bogaerts, Jan; Duez, Nicole; Cataliotti, Luigi; Klinkenbijl, Jean H. G.; Westenberg, Helen A.; van der Mijle, Huub; Snoj, Marko; Hurkmans, Coen; Rutgers, Emiel J. T.

    2010-01-01

    Background The randomized EORTC 10981-22023 AMAROS trial investigates whether breast cancer patients with a tumor-positive sentinel node biopsy (SNB) are best treated with an axillary lymph node dissection (ALND) or axillary radiotherapy (ART). The aim of the current substudy was to evaluate the identification rate and the nodal involvement. Methods The first 2,000 patients participating in the AMAROS trial were evaluated. Associations between the identification rate and technical, patient-, and tumor-related factors were evaluated. The outcome of the SNB procedure and potential further nodal involvement was assessed. Results In 65 patients, the sentinel node could not be identified. As a result, the sentinel node identification rate was 97% (1,888 of 1,953). Variables affecting the success rate were age, pathological tumor size, histology, year of accrual, and method of detection. The SNB results of 65% of the patients (n = 1,220) were negative and the patients underwent no further axillary treatment. The SNB results were positive in 34% of the patients (n = 647), including macrometastases (n = 409, 63%), micrometastases (n = 161, 25%), and isolated tumor cells (n = 77, 12%). Further nodal involvement in patients with macrometastases, micrometastases, and isolated tumor cells undergoing an ALND was 41, 18, and 18%, respectively. Conclusions With a 97% detection rate in this prospective international multicenter study, the SNB procedure is highly effective, especially when the combined method is used. Further nodal involvement in patients with micrometastases and isolated tumor cells in the sentinel node was similar—both were 18%. PMID:20300966

  15. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review.

    PubMed

    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

  16. EXTENSION OF THE 1D FOUR-GROUP ANALYTIC NODAL METHOD TO FULL MULTIGROUP

    SciTech Connect

    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.

  17. Nodal soliton solutions for generalized quasilinear Schrödinger equations

    SciTech Connect

    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.

  18. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review

    PubMed Central

    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

  19. Unidimensional Measurement May Evaluate Target Lymph Nodal Response After Induction Chemotherapy for Nasopharyngeal Carcinoma

    PubMed Central

    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

  20. The finite element absolute nodal coordinate formulation incorporated with surface stress effect to model elastic bending nanowires in large deformation

    NASA Astrophysics Data System (ADS)

    He, Jin; Lilley, Carmen M.

    2009-08-01

    Surface stress was incorporated into the finite element absolute nodal coordinate formulation in order to model elastic bending of nanowires in large deformation. The absolute nodal coordinate formulation is a numerical method to model bending structures in large deformation. The generalized Young-Laplace equation was employed to model the surface stress effect on bending nanowires. Effects from surface stress and large deformation on static bending nanowires are presented and discussed. The results calculated with the absolute nodal coordinate formulation incorporated with surface stress show that the surface stress effect makes the bending nanowires behave like softer or stiffer materials depending on the boundary condition. The surface stress effect diminishes as the dimensions of the bending structures increase beyond the nanoscale. The developed algorithm is consistent with the classical absolute nodal coordinate formulation at the macroscale.

  1. Nodal: master and commander of the dorsal-ventral and left-right axes in the sea urchin embryo.

    PubMed

    Molina, M Dolores; de Crozé, Noémie; Haillot, Emmanuel; Lepage, Thierry

    2013-08-01

    Recent studies suggest that specification of the dorsal-ventral and left-right axes of the sea urchin embryo relies on Nodal-expressing signalling centres located in the ventral ectoderm and in the archenteron that share striking similarities with vertebrate organising centres. Nodal and its downstream target BMP2/4 pattern all three germ layers along the dorsal-ventral axis, repress neural fates and control morphogenesis of the larva. Moreover, Nodal establishes left-right asymmetry by repressing formation of the adult rudiment and inhibiting germline cells differentiation on the right side, while BMP2/4 promotes expression of mesodermal genes on the left side. These findings provide a framework for future studies and raise new questions regarding the events upstream and downstream of Nodal and BMP signalling during axis formation. PMID:23769944

  2. Aeroacoustic Prediction Codes

    NASA Technical Reports Server (NTRS)

    Gliebe, P; Mani, R.; Shin, H.; Mitchell, B.; Ashford, G.; Salamah, S.; Connell, S.; Huff, Dennis (Technical Monitor)

    2000-01-01

    This report describes work performed on Contract NAS3-27720AoI 13 as part of the NASA Advanced Subsonic Transport (AST) Noise Reduction Technology effort. Computer codes were developed to provide quantitative prediction, design, and analysis capability for several aircraft engine noise sources. The objective was to provide improved, physics-based tools for exploration of noise-reduction concepts and understanding of experimental results. Methods and codes focused on fan broadband and 'buzz saw' noise and on low-emissions combustor noise and compliment work done by other contractors under the NASA AST program to develop methods and codes for fan harmonic tone noise and jet noise. The methods and codes developed and reported herein employ a wide range of approaches, from the strictly empirical to the completely computational, with some being semiempirical analytical, and/or analytical/computational. Emphasis was on capturing the essential physics while still considering method or code utility as a practical design and analysis tool for everyday engineering use. Codes and prediction models were developed for: (1) an improved empirical correlation model for fan rotor exit flow mean and turbulence properties, for use in predicting broadband noise generated by rotor exit flow turbulence interaction with downstream stator vanes: (2) fan broadband noise models for rotor and stator/turbulence interaction sources including 3D effects, noncompact-source effects. directivity modeling, and extensions to the rotor supersonic tip-speed regime; (3) fan multiple-pure-tone in-duct sound pressure prediction methodology based on computational fluid dynamics (CFD) analysis; and (4) low-emissions combustor prediction methodology and computer code based on CFD and actuator disk theory. In addition. the relative importance of dipole and quadrupole source mechanisms was studied using direct CFD source computation for a simple cascadeigust interaction problem, and an empirical combustor

  3. Formin DAAM1 Organizes Actin Filaments in the Cytoplasmic Nodal Actin Network

    PubMed Central

    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

  4. A coarse-mesh nodal method-diffusive-mesh finite difference method

    SciTech Connect

    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.

  5. A two-dimensional shear deformable beam element based on the absolute nodal coordinate formulation

    NASA Astrophysics Data System (ADS)

    Dufva, K. E.; Sopanen, J. T.; Mikkola, A. M.

    2005-02-01

    In this study, a new two-dimensional shear deformable beam element is proposed for large deformation problems. The kinematics of the beam are defined using an exact displacement field, where the rotation angles of the cross-section caused by bending and shear deformations are described separately. Cubic interpolation is used for determining the curvature of the beam due to bending, while linear interpolation polynomials are used for the shear strain. The absolute nodal coordinate formulation, in which global displacements and slopes are used as the nodal coordinates, is employed for the finite element discretization of the beam. The capability of the element to predict static deformation is studied using numerical examples. The results imply that the element is free of a phenomenon called shear-locking. The capability of the element to model highly nonlinear behaviour is established using a bending test where the cantilever is bent into a full circle using only four elements. A flexible pendulum and a spin-up manoeuvre are modelled in order to study the behaviour of the element in dynamical problems. The proposed element is also compared with an existing shear deformable beam element based on the absolute nodal coordinate formulation. Finally, the simple linearization of the beam curvature based on the assumption of small strain will be discussed.

  6. Nodal Liquid Theory of the Pseudo-Gap Phase of High-Tc Superconductors

    NASA Astrophysics Data System (ADS)

    Balents, Leon; Fisher, Matthew P. A.; Nayak, Chetan

    We introduce and study the nodal liquid, a novel zero-temperature quantum phase obtained by quantum-disordering a d-wave superconductor. It has numerous remarkable properties which lead us to suggest it as an explanation of the pseudo-gap state in underdoped high-temperature superconductors. In the absence of impurities, these include power-law magnetic order, a T-linear spin susceptibility, nontrivial thermal conductivity, and two- and one-particle charge gaps, the latter evidenced, e.g. in transport and electron photoemission (which exhibits pronounced fourfold anisotropy inherited from the d-wave quasiparticles). We use a (2+1)-dimensional duality transformation to derive an effective field theory for this phase. The theory is comprised of gapless neutral Dirac particles living at the former d-wave nodes, weakly coupled to the fluctuating gauge field of a dual Ginzburg-Landau theory. The nodal liquid interpolates naturally between the d-wave superconductor and the insulating antiferromagnet, and our effective field theory is powerful enough to permit a detailed analysis of a panoply of interesting phenomena, including charge ordering, antiferromagnetism, and d-wave superconductivity. We also discuss the zero-temperature quantum phase transitions which separate the nodal liquid from various ordered phases.

  7. Some results of a nodal method for nonlinear space-time reactor dynamics

    SciTech Connect

    Le, T.T.; Grossman, L.M.

    1991-12-31

    There are many reports about nodal methods for static and dynamic problems, but not many for the nonlinear feedback cases. In this paper, a class of nodal methods called ``mathematical nodal method`` (MNM) is studied with the temperature feedback problems. The spatially complex domain of the problem is represented as a collection of geometrically simple subdomains of the size of fuel assemblies called nodes. Over each node, the time dependent coefficients of the neutron flux, precursor concentrations, fuel and coolant temperatures are the surface and volume weighted average (moment) values of the unknown solutions; the space dependent basis functions are a combination of Legendre polynomials. If the material parameters are a linear function of fuel and coolant temperatures, the coupled equations can be put in a dimensionless form and a system of time dependent ordinary differential equations containing nonlinear feedback terms is obtained. These nonlinear feedback terms are updated at each time step during the time iteration process. Results of some benchmark problems are included in this report.

  8. Some results of a nodal method for nonlinear space-time reactor dynamics

    SciTech Connect

    Le, T.T. ); Grossman, L.M. . Dept. of Nuclear Engineering)

    1991-01-01

    There are many reports about nodal methods for static and dynamic problems, but not many for the nonlinear feedback cases. In this paper, a class of nodal methods called mathematical nodal method'' (MNM) is studied with the temperature feedback problems. The spatially complex domain of the problem is represented as a collection of geometrically simple subdomains of the size of fuel assemblies called nodes. Over each node, the time dependent coefficients of the neutron flux, precursor concentrations, fuel and coolant temperatures are the surface and volume weighted average (moment) values of the unknown solutions; the space dependent basis functions are a combination of Legendre polynomials. If the material parameters are a linear function of fuel and coolant temperatures, the coupled equations can be put in a dimensionless form and a system of time dependent ordinary differential equations containing nonlinear feedback terms is obtained. These nonlinear feedback terms are updated at each time step during the time iteration process. Results of some benchmark problems are included in this report.

  9. A Computational Model of Dynein Activation Patterns that Can Explain Nodal Cilia Rotation

    PubMed Central

    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

  10. Primary nodal peripheral T-cell lymphomas: diagnosis and therapeutic considerations

    PubMed Central

    Lage, Luis Alberto de Pádua Covas; Cabral, Tamara Carvalho dos Santos; Costa, Renata de Oliveira; Gonçalves, Marianne de Castro; Levy, Debora; Zerbini, Maria Cláudia Nogueira; Pereira, Juliana

    2015-01-01

    Nodal peripheral T-cell lymphomas are a rare group of neoplasms derived from post-thymic and activated T lymphocytes. A review of scientific articles listed in PubMed, Lilacs, and the Cochrane Library databases was performed using the term “peripheral T-cell lymphomas”. According to the World Health Organization classification of hematopoietic tissue tumors, this group of neoplasms consists of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase positive (ALCL-ALK+), and a provisional entity called anaplastic large cell lymphoma-anaplastic lymphoma kinase negative (ALCL-ALK−). Because the treatment and prognoses of these neoplasms involve different principles, it is essential to distinguish each one by its clinical, immunophenotypic, genetic, and molecular features. Except for anaplastic large cell lymphoma-anaplastic lymphoma kinase positive, which has no adverse international prognostic index, the prognosis of nodal peripheral T-cell lymphomas is worse than that of aggressive B-cell lymphomas. Chemotherapy based on anthracyclines provides poor outcomes because these neoplasms frequently have multidrug-resistant phenotypes. Based on this, the current tendency is to use intensified cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP) regimens with the addition of new drugs, and autologous hematopoietic stem cell transplantation. This paper describes the clinical features and diagnostic methods, and proposes a therapeutic algorithm for nodal peripheral T-cell lymphoma patients. PMID:26190436

  11. A computational model of dynein activation patterns that can explain nodal cilia rotation.

    PubMed

    Chen, Duanduan; Zhong, Yi

    2015-07-01

    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.

  12. A coarse-mesh nodal method, the diffusive-mesh finite difference method

    SciTech Connect

    Joo, H.; Nichols, W.R.

    1994-12-31

    Modern nodal methods have been successfully used for conventional light water reactor core analyses where the homogenized, node average cross section (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 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.

  13. Peripheral coding of taste

    PubMed Central

    Liman, Emily R.; Zhang, Yali V.; Montell, Craig

    2014-01-01

    Five canonical tastes, bitter, sweet, umami (amino acid), salty and sour (acid) are detected by animals as diverse as fruit flies and humans, consistent with a near universal drive to consume fundamental nutrients and to avoid toxins or other harmful compounds. Surprisingly, despite this strong conservation of basic taste qualities between vertebrates and invertebrates, the receptors and signaling mechanisms that mediate taste in each are highly divergent. The identification over the last two decades of receptors and other molecules that mediate taste has led to stunning advances in our understanding of the basic mechanisms of transduction and coding of information by the gustatory systems of vertebrates and invertebrates. In this review, we discuss recent advances in taste research, mainly from the fly and mammalian systems, and we highlight principles that are common across species, despite stark differences in receptor types. PMID:24607224

  14. Potential Pitfall in the Assessment of Lung Cancer with FDG-PET/CT: Talc Pleurodesis Causes Intrathoracic Nodal FDG Avidity

    PubMed Central

    Carter, Brett W.; Muse, Victorine; Digumarthy, Subba; Shepard, Jo-Anne; Sharma, Amita

    2013-01-01

    Objective. Talc pleurodesis is a common procedure performed to treat complications related to lung cancer. The purpose of our study was to characterize any thoracic nodal findings on FDG PET/CT associated with prior talc pleurodesis. Materials and Methods. The electronic medical record identified 44 patients who underwent PET/CT between January 2006 and December 2010 and had a history of talc pleurodesis. For each exam, we evaluated the distribution pattern, size, and attenuation of intrathoracic lymph nodes and the associated standardized uptake value. Results. High-attenuation intrathoracic lymph nodes were noted in 11 patients (25%), and all had corresponding increased FDG uptake (range 2–9 mm). Involved nodal groups were anterior peridiaphragmatic (100%), paracardiac (45%), internal mammary (25%), and peri-IVC (18%) nodal stations. Seven of the 11 patients (63%) had involvement of multiple lymph nodal groups. Mean longitudinal PET/CT and standalone CT followups of 15 ± 11 months showed persistence of both high-attenuation and increased uptake at these sites, without increase in nodal size suggesting metastatic disease involvement. Conclusions. FDG avid, high-attenuation lymph nodes along the lymphatic drainage pathway for parietal pleura are a relatively common finding following talc pleurodesis and should not be mistaken for nodal metastases during the evaluation of patients with history of lung cancer. PMID:26316941

  15. Advanced Chemical Propulsion Study

    NASA Technical Reports Server (NTRS)

    Woodcock, Gordon; Byers, Dave; Alexander, Leslie A.; Krebsbach, Al

    2004-01-01

    A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits to Code S missions. Several missions were selected from Code S planning data, and a range of advanced chemical propulsion options was analyzed to assess capabilities and benefits re these missions. Selected beneficial applications were found for higher-performing bipropellants, gelled propellants, and cryogenic propellants. Technology advancement recommendations included cryocoolers and small turbopump engines for cryogenic propellants; space storable propellants such as LOX-hydrazine; and advanced monopropellants. It was noted that fluorine-bearing oxidizers offer performance gains over more benign oxidizers. Potential benefits were observed for gelled propellants that could be allowed to freeze, then thawed for use.

  16. ASME Code Efforts Supporting HTGRs

    SciTech Connect

    D.K. Morton

    2012-09-01

    In 1999, an international collaborative initiative for the development of advanced (Generation IV) reactors was started. The idea behind this effort was to bring nuclear energy closer to the needs of sustainability, to increase proliferation resistance, and to support concepts able to produce energy (both electricity and process heat) at competitive costs. The U.S. Department of Energy has supported this effort by pursuing the development of the Next Generation Nuclear Plant, a high temperature gas-cooled reactor. This support has included research and development of pertinent data, initial regulatory discussions, and engineering support of various codes and standards development. This report discusses the various applicable American Society of Mechanical Engineers (ASME) codes and standards that are being developed to support these high temperature gascooled reactors during construction and operation. ASME is aggressively pursuing these codes and standards to support an international effort to build the next generation of advanced reactors so that all can benefit.

  17. ASME Code Efforts Supporting HTGRs

    SciTech Connect

    D.K. Morton

    2011-09-01

    In 1999, an international collaborative initiative for the development of advanced (Generation IV) reactors was started. The idea behind this effort was to bring nuclear energy closer to the needs of sustainability, to increase proliferation resistance, and to support concepts able to produce energy (both electricity and process heat) at competitive costs. The U.S. Department of Energy has supported this effort by pursuing the development of the Next Generation Nuclear Plant, a high temperature gas-cooled reactor. This support has included research and development of pertinent data, initial regulatory discussions, and engineering support of various codes and standards development. This report discusses the various applicable American Society of Mechanical Engineers (ASME) codes and standards that are being developed to support these high temperature gascooled reactors during construction and operation. ASME is aggressively pursuing these codes and standards to support an international effort to build the next generation of advanced reactors so that all can benefit.

  18. ASME Code Efforts Supporting HTGRs

    SciTech Connect

    D.K. Morton

    2010-09-01

    In 1999, an international collaborative initiative for the development of advanced (Generation IV) reactors was started. The idea behind this effort was to bring nuclear energy closer to the needs of sustainability, to increase proliferation resistance, and to support concepts able to produce energy (both electricity and process heat) at competitive costs. The U.S. Department of Energy has supported this effort by pursuing the development of the Next Generation Nuclear Plant, a high temperature gas-cooled reactor. This support has included research and development of pertinent data, initial regulatory discussions, and engineering support of various codes and standards development. This report discusses the various applicable American Society of Mechanical Engineers (ASME) codes and standards that are being developed to support these high temperature gascooled reactors during construction and operation. ASME is aggressively pursuing these codes and standards to support an international effort to build the next generation of advanced reactors so that all can benefit.

  19. De-coding and re-coding RNA recognition by PUF and PPR repeat proteins.

    PubMed

    Hall, Traci M Tanaka

    2016-02-01

    PUF and PPR proteins are two families of α-helical repeat proteins that recognize single-stranded RNA sequences. Both protein families hold promise as scaffolds for designed RNA-binding domains. A modular protein RNA recognition code was apparent from the first crystal structures of a PUF protein in complex with RNA, and recent studies continue to advance our understanding of natural PUF protein recognition (de-coding) and our ability to engineer specificity (re-coding). Degenerate recognition motifs make de-coding specificity of individual PPR proteins challenging. Nevertheless, re-coding PPR protein specificity using a consensus recognition code has been successful.

  20. PUMA-PCCS separate effect tests and RELAP5 code evaluation in PUMA

    NASA Astrophysics Data System (ADS)

    Choi, Sung Won

    One of the key areas in the design of advanced nuclear reactors is to develop a reliable Passive Containment Cooling System (PCCS). The purpose of the current work is to better understand the condensation phenomena in PCCS for the downward co-current flow of a steam/air mixture through condenser tube bundles during the three PCCS operational modes, namely the bypass mode, the cyclic venting mode and the long-term cooling mode. A series of unique separate-effect PCCS test data were obtained for condensation heat transfer in the PCCS heat exchangers of the PUMA (Purdue University Multidimensional Integral Test Assembly) facility under a task sponsored by the U.S. Nuclear Regulatory Commission. Test conditions includes bypass mode, cyclic venting mode and long term mode, covering a wide range of Loss of Coolant Accident(LOCA) conditions with a parameters of pressure, mass flow rate, noncondensable(NC) gases, and PCCS pool water level. The parametric effect studies and a further validation of the PUMA-PCCS separate effect test data were performed. The evaluation of a best estimate system code (RELAP5/MOD3.3) was performed by using unique PUMA-PCCS separate effects data and PUMA-Main Steam Line Break (MSLB) integral test (1998). Through a sensitivity studies of nodalization method and physical models on the MSLB test simulations, deficiencies in RELAP5/MOD3.3 code were found as follows: (1) over prediction of heat removal rate by condensation models, (2) overestimation of SP heat transfer through the horizontal venting line and thermal stratification distortion, (3) underestimation of NC gas effects in PCCS by the distortion of cyclic venting phenomena and (4) overestimation of the DW and SP wall condensation. The improvement for the code calculation predictions could be obtained by removing the RELAP5/MOD3.3 code deficient factors in the PUMA MSLB integral test simulation. The unique PCCS NC gas venting visualizations were obtained according to various PCCS inlet NC

  1. Regional Nodal Recurrence After Breast Conservation Treatment With Radiotherapy for Women With Early-Stage Breast Carcinoma

    SciTech Connect

    Lukens, J. Nicholas Vapiwala, Neha; Hwang, W.-T.; Solin, Lawrence J.

    2009-04-01

    Purpose: To report the long-term outcomes for women presenting with regional lymph node recurrence after breast conservation treatment with radiotherapy for Stage I and II invasive breast carcinoma. Methods and Materials: Of the women with pathologic Stage I and II invasive breast carcinoma treated with breast conservation treatment at University of Pennsylvania, 29 developed regional nodal recurrence as their first site of failure. An analysis of the patterns of regional nodal recurrence and their prognosis after recurrence was undertaken. The median follow-up from regional nodal recurrence was 5.4 years. Results: The pattern of regional nodal recurrence was as follows: 14 (48%) with simultaneous local and axillary recurrence, 7 (24%) with recurrence in the axilla only, 5 (17%) with recurrence in the supraclavicular region only, and 3 (10%) with multiple nodal sites of recurrence. For the entire study group, the 5-, 10-, and 15-year overall survival rate was 70%, 37%, and 28%, respectively. The 10-year overall survival rate for patients with locoregional recurrence was 32% compared with 45% for patients with regional-only recurrence (p = 0.50). The 10-year overall survival rate for patients with axillary recurrence discovered on pathologic examination of the mastectomy specimen was 31% compared with 42% for patients with palpable regional lymphadenopathy (p = 0.83). Conclusion: Patients with regional nodal recurrence after breast conservation treatment with radiotherapy for early-stage breast carcinoma are potentially salvageable. The prognosis after regional nodal recurrence was not significantly different when stratified by the presence or absence of simultaneous in-breast recurrence or the method of detection.

  2. NodalB{copyright}: A unique program for optimum production of sucker rod pumping oil wells

    SciTech Connect

    Guirados, C.D.; Ercolino, J.M.; Sandoval, J.L.

    1995-12-31

    Sucker rod pumping is the oldest artificial lift method used in production of oil wells. This method is usually designed and analyzed with the assistance of programs based on simplified models, such as the API RP 11L, or with a wave equation simulator. In many cases, however, a technique that permits consideration of the inflow and outflow performance of the well is a more efficient way to design and analyze an oil well. This technique, referred to as Total Analysis or System Analysis (SA), has been successfully applied to flowing and artificially lifted wells. This paper presents a computer program developed by Intevep S.A., called NodalB{copyright}, created to perform the SA of sucker rod pumping wells. NodalB{copyright}`s unique characteristics make it a competitive program in today`s market of design and optimization software. This program allows consideration of the inflow performance of the reservoir depending on the drilling scheme, either vertical or horizontal, and determination of the sensitivity of the rod pumping system to its most relevant parameters, such as: pumping speed and stroke, pump diameter, gas oil ratio, gas separation efficiency, tubing diameter, pump depth, rod string design, oil viscosity, injected diluent (diesel, kerosene, etc.) ratio, water cut, reservoir pressure, productivity index, and different production schemes (i.e. production through the tubing or through the casing-tubing annulus). These features show the power of this program as a predictive tool. NodalB{copyright} is specially applicable to design, optimization and troubleshooting of heavy and viscous oil wells, taking into account the viscosity effects in the rod pumping system.

  3. Plant regeneration from single-nodal-stem explants of legume tree Prosopis alba Griseb.

    PubMed

    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.

  4. System analysis with improved thermo-mechanical fuel rod models for modeling current and advanced LWR materials in accident scenarios

    NASA Astrophysics Data System (ADS)

    Porter, Ian Edward

    A nuclear reactor systems code has the ability to model the system response in an accident scenario based on known initial conditions at the onset of the transient. However, there has been a tendency for these codes to lack the detailed thermo-mechanical fuel rod response models needed for accurate prediction of fuel rod failure. This proposed work will couple today's most widely used steady-state (FRAPCON) and transient (FRAPTRAN) fuel rod models with a systems code TRACE for best-estimate modeling of system response in accident scenarios such as a loss of coolant accident (LOCA). In doing so, code modifications will be made to model gamma heating in LWRs during steady-state and accident conditions and to improve fuel rod thermal/mechanical analysis by allowing axial nodalization of burnup-dependent phenomena such as swelling, cladding creep and oxidation. With the ability to model both burnup-dependent parameters and transient fuel rod response, a fuel dispersal study will be conducted using a hypothetical accident scenario under both PWR and BWR conditions to determine the amount of fuel dispersed under varying conditions. Due to the fuel fragmentation size and internal rod pressure both being dependent on burnup, this analysis will be conducted at beginning, middle and end of cycle to examine the effects that cycle time can play on fuel rod failure and dispersal. Current fuel rod and system codes used by the Nuclear Regulatory Commission (NRC) are compilations of legacy codes with only commonly used light water reactor materials, Uranium Dioxide (UO2), Mixed Oxide (U/PuO 2) and zirconium alloys. However, the events at Fukushima Daiichi and Three Mile Island accident have shown the need for exploration into advanced materials possessing improved accident tolerance. This work looks to further modify the NRC codes to include silicon carbide (SiC), an advanced cladding material proposed by current DOE funded research on accident tolerant fuels (ATF). Several

  5. Optimal three-dimensional reusable tug trajectories for planetary missions including correction for nodal precession

    NASA Technical Reports Server (NTRS)

    Borsody, J.

    1976-01-01

    Equations are derived by using the maximum principle to maximize the payload of a reusable tug for planetary missions. The analysis includes a correction for precession of the space shuttle orbit. The tug returns to this precessed orbit (within a specified time) and makes the required nodal correction. A sample case is analyzed that represents an inner planet mission as specified by a fixed declination and right ascension of the outgoing asymptote and the mission energy. The reusable stage performance corresponds to that of a typical cryogenic tug. Effects of space shuttle orbital inclination, several trajectory parameters, and tug thrust on payload are also investigated.

  6. [Successful ablation of an atrioventricular nodal reentrant tachycardia ablation 2 years after orthotopic heart transplantation].

    PubMed

    Bellmann, Barbara; Reith, Sebastian; Gemein, Christopher; Schauerte, Patrick

    2015-09-01

    We report the case of a 48-year-old woman with an orthotopic heart transplantation. Two years after transplantation, the patient reported intermittent palpitations and dyspnea. The results of the 12-lead electrogram provided suspicion of AV nodal reentrant tachycardia (AVNRT), which was confirmed in the electrophysiological examination. The AVNRT was successfully eliminated without complications by radiofrequency catheter ablation of the slow pathway. The case shows that an AVNRT, even with existing sinus rhythm of the original heart, can also occur on the transplanted heart and ablation is safe and feasible. PMID:26208808

  7. Treatment of paroxysmal nodal tachycardia by dual demand pacemaker in the coronary sinus.

    PubMed Central

    O'Keeffe, D B; Curry, P V; Sowton, E

    1981-01-01

    A patient with refractory paroxysmal atrioventricular nodal re-entrant tachycardia had required direct current cardioversion to terminate attacks on 83 occasions. A dual demand pacemaker was implanted to sense and interrupt attacks of tachycardia automatically. The pacing electrode was positioned in the proximal coronary sinus near to the atrioventricular node; a site from which fixed rate underdrive pacing successfully interrupted attacks throughout a trial period of one week, with a lead left in this position on a temporary basis. Complete control of the arrhythmia was obtained in the six months after pacemaker implantation. Images PMID:7459160

  8. Light Spectral Quality Effects on the Growth of Potato (Solanum Tuberosum L.) Nodal Cutttings in Vitro

    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.

  9. Nodal promotes the self-renewal of human colon cancer stem cells via an autocrine manner through Smad2/3 signaling pathway.

    PubMed

    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.

  10. Accuracy of Computed Tomography for Predicting Pathologic Nodal Extracapsular Extension in Patients With Head-and-Neck Cancer Undergoing Initial Surgical Resection

    SciTech Connect

    Prabhu, Roshan S.; Magliocca, Kelly R.; Hanasoge, Sheela; Aiken, Ashley H.; Hudgins, Patricia A.; Hall, William A.; Chen, Susie A.; Eaton, Bree R.; Higgins, Kristin A.; Saba, Nabil F.; Beitler, Jonathan J.

    2014-01-01

    Purpose: Nodal extracapsular extension (ECE) in patients with head-and-neck cancer increases the loco-regional failure risk and is an indication for adjuvant chemoradiation therapy (CRT). To reduce the risk of requiring trimodality therapy, patients with head-and-neck cancer who are surgical candidates are often treated with definitive CRT when preoperative computed tomographic imaging suggests radiographic ECE. The purpose of this study was to assess the accuracy of preoperative CT imaging for predicting pathologic nodal ECE (pECE). Methods and Materials: The study population consisted of 432 consecutive patients with oral cavity or locally advanced/nonfunctional laryngeal cancer who underwent preoperative CT imaging before initial surgical resection and neck dissection. Specimens with pECE had the extent of ECE graded on a scale from 1 to 4. Results: Radiographic ECE was documented in 46 patients (10.6%), and pECE was observed in 87 (20.1%). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 43.7%, 97.7%, 82.6%, and 87.3%, respectively. The sensitivity of radiographic ECE increased from 18.8% for grade 1 to 2 ECE, to 52.9% for grade 3, and 72.2% for grade 4. Radiographic ECE criteria of adjacent structure invasion was a better predictor than irregular borders/fat stranding for pECE. Conclusions: Radiographic ECE has poor sensitivity, but excellent specificity for pECE in patients who undergo initial surgical resection. PPV and NPV are reasonable for clinical decision making. The performance of preoperative CT imaging increased as pECE grade increased. Patients with resectable head-and-neck cancer with radiographic ECE based on adjacent structure invasion are at high risk for high-grade pECE requiring adjuvant CRT when treated with initial surgery; definitive CRT as an alternative should be considered where appropriate.

  11. Nodal and BMP2/4 signaling organizes the oral-aboral axis of the sea urchin embryo.

    PubMed

    Duboc, Véronique; Röttinger, Eric; Besnardeau, Lydia; Lepage, Thierry

    2004-03-01

    In the sea urchin embryo, the oral-aboral axis is specified after fertilization by mechanisms that are largely unknown. We report that early sea urchin embryos express Nodal and Antivin in the presumptive oral ectoderm and demonstrate that these genes control formation of the oral-aboral axis. Overexpression of nodal converted the whole ectoderm into oral ectoderm and induced ectopic expression of the orally expressed genes goosecoid, brachyury, BMP2/4, and antivin. Conversely, when the function of Nodal was blocked, by injection of an antisense Morpholino oligonucleotide or by injection of antivin mRNA, neither the oral nor the aboral ectoderm were specified. Injection of nodal mRNA into Nodal-deficient embryos induced an oral-aboral axis in a largely non-cell-autonomous manner. These observations suggest that the mechanisms responsible for patterning the oral-aboral axis of the sea urchin embryo may share similarities with mechanisms that pattern the dorsoventral axis of other deuterostomes.

  12. Indications for Pelvic Nodal Treatment in Prostate Cancer Should Change. Validation of the Roach Formula in a Large Extended Nodal Dissection Series

    SciTech Connect

    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

  13. 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.

  14. New Method for Imaging Gap Nodal Structure of Unconventional Superconductors through the Anisotropic Nonlinear Meissner Effect

    NASA Astrophysics Data System (ADS)

    Bae, Seokjin; Tan, Yuewen; Gogna, Rahul; Mendelsohn, Nathan; Remillard, Steven; Anlage, Steven

    We present a new measurement method which can be used to image gap nodal structure of superconductors whose pairing symmetry is unknown. This method utilizes photoresponse from a microwave resonance of the superconducting sample perturbed by a scanned laser spot. For an epitaxial or single crystal sample, the anisotropy of this photoresponse is directly related to that of gap function via the non-linear Meissner coefficient, so the gap nodal directions can be inferred from the photoresponse image. The significant advantage of the presented method over previous spiral or lumped circuit resonator methods is that it does not require a complicated lithographic patterning process which often degrades superconductivity or introduces defect-dominant photoresponse and hence limits one from testing various kinds of materials. The validity of the method is confirmed both by HFSS simulation and experiments on unpatterned superconducting thin films. Photoresponse images from example unconventional superconductors will be also presented and discussed. This work is supported by the NSF Grants DMR-1410712.

  15. Cooperative Wnt-Nodal Signals Regulate the Patterning of Anterior Neuroectoderm

    PubMed Central

    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

  16. Comparison of Nodal Risk Formula and MR Lymphography for Predicting Lymph Node Involvement in Prostate Cancer

    SciTech Connect

    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.

  17. 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.

  18. Nanog-like Regulates Endoderm Formation through the Mxtx2-Nodal Pathway

    PubMed Central

    Xu, Cong; Fan, Zi Peng; Müller, Patrick; Fogley, Rachel; DiBiase, Anthony; Trompouki, Eirini; Unternaehrer, Juli; Xiong, Fengzhu; Torregroza, Ingrid; Evans, Todd; Megason, Sean G.; Daley, George Q.; Schier, Alexander F.; Young, Richard A.; Zon, Leonard I.

    2012-01-01

    SUMMARY In mammalian embryonic stem cells, the acquisition of pluripotency is dependent upon Nanog, but the in vivo analysis of Nanog has been hampered by its requirement for early mouse development. In an effort to examine the role of Nanog in vivo, we identified a zebrafish Nanog ortholog, and found that its knockdown impaired endoderm formation. Genome-wide transcription analysis revealed that nanog-like morphants fail to develop the extra-embryonic yolk syncytial layer (YSL), which produces Nodal required for endoderm induction. We examined the genes that were regulated by Nanog-like, and identified the homeobox gene mxtx2, which is both necessary and sufficient for YSL induction. Chromatin immunoprecipitation assays and genetic studies indicated that Nanog-like directly activates mxtx2, which in turn specifies the YSL lineage by directly activating YSL genes. Our study identifies a Nanog-like-Mxtx2-Nodal pathway and establishes a role for Nanog-like in regulating the formation of the extra-embryonic tissue required for endoderm induction. PMID:22421047

  19. [Successful selective electrical ablation of the retrograde pathway in atrioventricular nodal reentry tachycardia associated with syncope].

    PubMed

    Lukl, J; Cíhalík, C

    1992-01-01

    A 55-year-old man was admitted to the intensive care unit on account of repeatedly occurring syncopes which developed at the peak of physical exertion. The attack was reproduced by exercise on a bicycle ergometer: the patient developed paroxysmal tachycardia with a narrow QRS and a frequency of 160/min leading after 20 sec. to severe hypotension and loss of consciousness. The same tachycardia caused by programmed atrial stimulation caused a drop of tension in the recumbent position by 30 mmHg and after more detailed analysis during electrophysiological examination it was evaluated as atrioventricular nodal reentrant tachycardia. By an electric discharge of 300 J administered by means of a stimulation electrode 7F USCI into the area of the AV node the retrograde conduction through the perinodal rapid pathways was completely interrupted and 1st. degree atrioventricular block developed. Repeated electrophysiological examination and exercise tests on a bicycle ergometer provided evidence of the disappearance of the retrograde pathway and the impossibility to elicit AVNRT. The authors express the view that the rapid perinodal pathway is interrupted in successful cases in both directions and the 1st. degree AV block is due to conduction along a slow pathway and not incidental slowing of conduction along the rapid pathway which is the generally accepted interpretation. Modification of the atrioventricular conduction by interruption of the rapid pathway by fulguration is according to data in the literature and the described patient a method which makes is possible to cure severe atrioventricular nodal reentrant tachycardias.

  20. Nodal marginal zone B cells in mice: a novel subset with dormant self-reactivity

    PubMed Central

    Palm, Anna-Karin E.; Friedrich, Heike C.; Kleinau, Sandra

    2016-01-01

    Marginal zone (MZ) B cells, representing a distinct subset of innate-like B cells, mount rapid T-independent responses to blood-borne antigens. They express low-affinity polyreactive antigen receptors that recognize both foreign and self-structures. The spleen is considered the exclusive site for murine MZ B cells. However, we have here identified B cells with a MZ B-cell phenotype in the subcapsular sinuses of mouse lymph nodes. The nodal MZ (nMZ) B cells display high levels of IgM, costimulators and TLRs, and are represented by naïve and memory cells. The frequency of nMZ B cells is about 1–6% of nodal B cells depending on mouse strain, with higher numbers in older mice and a trend of increased numbers in females. There is a significant expansion of nMZ B cells following immunization with an autoantigen, but not after likewise immunization with a control protein or with the adjuvant alone. The nMZ B cells secrete autoantibodies upon activation and can efficiently present autoantigen to cognate T cells in vitro, inducing T-cell proliferation. The existence of self-reactive MZ B cells in lymph nodes may be a source of autoantigen-presenting cells that in an unfortunate environment may activate T cells leading to autoimmunity. PMID:27277419

  1. Cooperative Wnt-Nodal Signals Regulate the Patterning of Anterior Neuroectoderm.

    PubMed

    Yaguchi, Junko; Takeda, Noriyo; Inaba, Kazuo; Yaguchi, Shunsuke

    2016-04-01

    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

  2. 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.

  3. 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.

  4. Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates

    DOE PAGES

    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

  5. Conservation defines functional motifs in the squint/nodal-related 1 RNA dorsal localization element

    PubMed Central

    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

  6. Misalignment-induced nodal aberration fields in two-mirror astronomical telescopes.

    PubMed

    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).

  7. Homological stabilizer codes

    SciTech Connect

    Anderson, Jonas T.

    2013-03-15

    In this paper we define homological stabilizer codes on qubits which encompass codes such as Kitaev's toric code and the topological color codes. These codes are defined solely by the graphs they reside on. This feature allows us to use properties of topological graph theory to determine the graphs which are suitable as homological stabilizer codes. We then show that all toric codes are equivalent to homological stabilizer codes on 4-valent graphs. We show that the topological color codes and toric codes correspond to two distinct classes of graphs. We define the notion of label set equivalencies and show that under a small set of constraints the only homological stabilizer codes without local logical operators are equivalent to Kitaev's toric code or to the topological color codes. - Highlights: Black-Right-Pointing-Pointer We show that Kitaev's toric codes are equivalent to homological stabilizer codes on 4-valent graphs. Black-Right-Pointing-Pointer We show that toric codes and color codes correspond to homological stabilizer codes on distinct graphs. Black-Right-Pointing-Pointer We find and classify all 2D homological stabilizer codes. Black-Right-Pointing-Pointer We find optimal codes among the homological stabilizer codes.

  8. Universal heat conduction in Ce1 -xYbxCoIn5 : Evidence for robust nodal d -wave superconducting gap

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Dong, J. K.; Lum, I. K.; Zhang, J.; Hong, X. C.; He, L. P.; Wang, K. F.; Ma, Y. C.; Petrovic, C.; Maple, M. B.; Shu, L.; Li, S. Y.

    2016-02-01

    In the heavy-fermion superconductor Ce1 -xYbxCoIn5 , Yb doping was reported to cause a possible change from nodal d -wave superconductivity to a fully gapped d -wave molecular superfluid of composite pairs near x ≈0.07 (nominal value xnom=0.2 ). Here we present systematic thermal conductivity measurements on Ce1 -xYbxCoIn5 (x =0.013 , 0.084, and 0.163) single crystals. The observed finite residual linear term κ0/T is insensitive to Yb doping, verifying the universal heat conduction of the nodal d -wave superconducting gap in Ce1 -xYbxCoIn5 . Similar universal heat conduction is also observed in the CeCo (In1 -yCdy )5 system. These results reveal a robust nodal d -wave gap in CeCoIn5 upon Yb or Cd doping.

  9. Shifting nodal-plane suppressions in high-order-harmonic spectra from diatomic molecules in orthogonally polarized driving fields

    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.

  10. Spin-orbit interaction driven collective electron-hole excitations in a noncentrosymmetric nodal loop Weyl semimetal

    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.

  11. NASA Rotor 37 CFD Code Validation: Glenn-HT Code

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.

    2010-01-01

    In order to advance the goals of NASA aeronautics programs, it is necessary to continuously evaluate and improve the computational tools used for research and design at NASA. One such code is the Glenn-HT code which is used at NASA Glenn Research Center (GRC) for turbomachinery computations. Although the code has been thoroughly validated for turbine heat transfer computations, it has not been utilized for compressors. In this work, Glenn-HT was used to compute the flow in a transonic compressor and comparisons were made to experimental data. The results presented here are in good agreement with this data. Most of the measures of performance are well within the measurement uncertainties and the exit profiles of interest agree with the experimental measurements.

  12. Atlas-Based Segmentation Improves Consistency and Decreases Time Required for Contouring Postoperative Endometrial Cancer Nodal Volumes

    SciTech Connect

    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

  13. Coding of Neuroinfectious Diseases.

    PubMed

    Barkley, Gregory L

    2015-12-01

    Accurate coding is an important function of neurologic practice. This contribution to Continuum is part of an ongoing series that presents helpful coding information along with examples related to the issue topic. Tips for diagnosis coding, Evaluation and Management coding, procedure coding, or a combination are presented, depending on which is most applicable to the subject area of the issue. PMID:26633789

  14. Model Children's Code.

    ERIC Educational Resources Information Center

    New Mexico Univ., Albuquerque. American Indian Law Center.

    The Model Children's Code was developed to provide a legally correct model code that American Indian tribes can use to enact children's codes that fulfill their legal, cultural and economic needs. Code sections cover the court system, jurisdiction, juvenile offender procedures, minor-in-need-of-care, and termination. Almost every Code section is…

  15. A Comprehensive Validation Approach Using The RAVEN Code

    SciTech Connect

    Alfonsi, Andrea; Rabiti, Cristian; Cogliati, Joshua J; Rinaldi, Ivan; Giannetti, Fabio; Caruso, Gianfranco

    2015-06-01

    The RAVEN computer code , developed at the Idaho National Laboratory, is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is a multi-purpose probabilistic and uncertainty quantification platform, capable to communicate with any system code. A natural extension of the RAVEN capabilities is the imple- mentation of an integrated validation methodology, involving several different metrics, that represent an evolution of the methods currently used in the field. The state-of-art vali- dation approaches use neither exploration of the input space through sampling strategies, nor a comprehensive variety of metrics needed to interpret the code responses, with respect experimental data. The RAVEN code allows to address both these lacks. In the following sections, the employed methodology, and its application to the newer developed thermal-hydraulic code RELAP-7, is reported.The validation approach has been applied on an integral effect experiment, representing natu- ral circulation, based on the activities performed by EG&G Idaho. Four different experiment configurations have been considered and nodalized.

  16. Performance of a recoverable tug for planetary missions including use of perigee propulsion and corrections for nodal regression

    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.

  17. Phase I Trial of Pelvic Nodal Dose Escalation With Hypofractionated IMRT for High-Risk Prostate Cancer

    SciTech Connect

    Adkison, Jarrod B.; McHaffie, Derek R.; Bentzen, Soren M.; Patel, Rakesh R.; Khuntia, Deepak; Petereit, Daniel G.; Hong, Theodore S.; Tome, Wolfgang; Ritter, Mark A.

    2012-01-01

    Purpose: Toxicity concerns have limited pelvic nodal prescriptions to doses that may be suboptimal for controlling microscopic disease. In a prospective trial, we tested whether image-guided intensity-modulated radiation therapy (IMRT) can safely deliver escalated nodal doses while treating the prostate with hypofractionated radiotherapy in 5 Vulgar-Fraction-One-Half weeks. Methods and Materials: Pelvic nodal and prostatic image-guided IMRT was delivered to 53 National Comprehensive Cancer Network (NCCN) high-risk patients to a nodal dose of 56 Gy in 2-Gy fractions with concomitant treatment of the prostate to 70 Gy in 28 fractions of 2.5 Gy, and 50 of 53 patients received androgen deprivation for a median duration of 12 months. Results: The median follow-up time was 25.4 months (range, 4.2-57.2). No early Grade 3 Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events v.3.0 genitourinary (GU) or gastrointestinal (GI) toxicities were seen. The cumulative actuarial incidence of Grade 2 early GU toxicity (primarily alpha blocker initiation) was 38%. The rate was 32% for Grade 2 early GI toxicity. None of the dose-volume descriptors correlated with GU toxicity, and only the volume of bowel receiving {>=}30 Gy correlated with early GI toxicity (p = 0.029). Maximum late Grades 1, 2, and 3 GU toxicities were seen in 30%, 25%, and 2% of patients, respectively. Maximum late Grades 1 and 2 GI toxicities were seen in 30% and 8% (rectal bleeding requiring cautery) of patients, respectively. The estimated 3-year biochemical control (nadir + 2) was 81.2 {+-} 6.6%. No patient manifested pelvic nodal failure, whereas 2 experienced paraaortic nodal failure outside the field. The six other clinical failures were distant only. Conclusions: Pelvic IMRT nodal dose escalation to 56 Gy was delivered concurrently with 70 Gy of hypofractionated prostate radiotherapy in a convenient, resource-efficient, and well-tolerated 28-fraction schedule. Pelvic nodal dose

  18. An analytical discrete ordinates solution for a nodal model of a two-dimensional neutron transport problem

    SciTech Connect

    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)

  19. Nodal Gap” induced by the incommensurate diagonal spin density modulation in underdoped high- Tc superconductors

    DOE PAGES

    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

  20. To Code or Not To Code?

    ERIC Educational Resources Information Center

    Parkinson, Brian; Sandhu, Parveen; Lacorte, Manel; Gourlay, Lesley

    1998-01-01

    This article considers arguments for and against the use of coding systems in classroom-based language research and touches on some relevant considerations from ethnographic and conversational analysis approaches. The four authors each explain and elaborate on their practical decision to code or not to code events or utterances at a specific point…

  1. Bare Code Reader

    NASA Astrophysics Data System (ADS)

    Clair, Jean J.

    1980-05-01

    The Bare code system will be used, in every market and supermarket. The code, which is normalised in US and Europe (code EAN) gives informations on price, storage, nature and allows in real time the gestion of theshop.

  2. Intra-atrial conduction block mimicking atrioventricular nodal block after multiple catheter ablation procedures for atrial tachycardia in a patient with cardiomyopathy.

    PubMed

    Chugh, Aman; Yokokawa, Miki; Baman, Timir; Bogun, Frank; Wu, Audrey

    2012-11-01

    A 42-year-old woman with a history of cardiomyopathy and multiple ablation procedures for atrial tachycardia developed intra-atrial conduction block that mimicked atrioventricular (AV) nodal block during radiofrequency ablation at the cavotricuspid isthmus. She was treated with atrial pacing (from the coronary sinus), which overcame intra-atrial conduction block and resulted in AV nodal conduction.

  3. Performance of seminal and nodal roots of wheat in stagnant solution: K+ and P uptake and effects of increasing O2 partial pressures around the shoot on nodal root elongation.

    PubMed

    Wiengweera, Amara; Greenway, Hank

    2004-09-01

    Roots of intact wheat plants were grown for 7-12 d in stagnant nutrient solution, containing 0.1% agar, to mimic the lack of convection in waterlogged soil. Net K+ and P uptakes by seminal and nodal roots were measured separately using a split root system. For seminal roots in stagnant solution, net uptakes as a percentage of aerated roots were between 0% and 16% for P, while K+ ranged between 15% uptake and 54% loss. For the more waterlogging-tolerant nodal roots, net uptakes in stagnant nutrient solution, as a percentage of aerated roots, were 31-73% for P and 69-115% for K+. Elongation rates of nodal roots in stagnant nutrient were about 35-43% of those for roots in aerated solution. This partial inhibition occurred in these nodal roots despite their 15% porosity (v/v). Elevation of O2 partial pressures around the shoots to 40 kPa and then to 80 kPa substantially accelerated nodal root elongation in stagnant solution, demonstrating that most of the inhibition seen with ambient O2 around the shoots was associated with a restricted O2 supply to these nodal roots. Thus, in wheat nodal roots, with a partial pressure of 20 kPa O2 around the shoots, O2 diffusion from the shoots did not completely relieve the restrictions on elongation resulting from stagnancy in the nutrient solution. These results contrast with those in the literature for rice, in which roots function efficiently in stagnant solutions (0.1% agar). So, when wheat roots are aerenchymatous there are still restrictions to O2 diffusion in the gas space continuum between the atmosphere and the functional tissues of the roots. This poor acclimation must have been due to inefficiency of the aerenchymatous axes, which may include persistence of anoxic steles, and/or restricted O2 diffusion in other parts of the gas space continuum, in either the shoots and shoot-root junction or in the root tip.

  4. Development of Visualization Software for McCARD Code

    NASA Astrophysics Data System (ADS)

    Park, Chang Je; Lee, Byungchul; Shim, Hyung Jin; Yoeng Choi, Kwang; Roh, Chang Hyun

    2014-06-01

    In order to confirm geometrical modeling of input file of the McCARD (Monte Carlo Code for Advanced Reactor Design and analysis) code, a 2D visualization program with a 3D modeling has been developed. It requires lots of mathematical operations and advanced technologies for design graphical program of complicated geometries. The software is coded with the visual C++ language and run under the Windows PC environment.

  5. NODAL secreted by male germ cells regulates the proliferation and function of human Sertoli cells from obstructive azoospermia and nonobstructive azoospermia patients

    PubMed Central

    Tian, Ru-Hui; Yang, Shi; Zhu, Zi-Jue; Wang, Jun-Long; Liu, Yun; Yao, Chencheng; Ma, Meng; Guo, Ying; Yuan, Qingqing; Hai, Yanan; Huang, Yi-Ran; He, Zuping; Li, Zheng

    2015-01-01

    This study was designed to explore the regulatory effects of male germ cell secreting factor NODAL on Sertoli cell fate decisions from obstructive azoospermia (OA) and nonobstructive azoospermia (NOA) patients. Human Sertoli cells and male germ cells were isolated using two-step enzymatic digestion and SATPUT from testes of azoospermia patients. Expression of NODAL and its multiple receptors in human Sertoli cells and male germ cells were characterized by reverse transcription-polymerase chain reaction (RT-PCR) and immunochemistry. Human recombinant NODAL and its receptor inhibitor SB431542 were employed to probe their effect on the proliferation of Sertoli cells using the CCK-8 assay. Quantitative PCR and Western blots were utilized to assess the expression of Sertoli cell functional genes and proteins. NODAL was found to be expressed in male germ cells but not in Sertoli cells, whereas its receptors ALK4, ALK7, and ACTR-IIB were detected in Sertoli cells and germ cells, suggesting that NODAL plays a regulatory role in Sertoli cells and germ cells via a paracrine and autocrine pathway, respectively. Human recombinant NODAL could promote the proliferation of human Sertoli cells. The expression of cell cycle regulators, including CYCLIN A, CYCLIN D1 and CYCLIN E, was not remarkably affected by NODAL signaling. NODAL enhanced the expression of essential growth factors, including GDNF, SCF, and BMP4, whereas SB431542 decreased their levels. There was not homogeneity of genes changes by NODAL treatment in Sertoli cells from OA and Sertoli cell-only syndrome (SCO) patients. Collectively, this study demonstrates that NODAL produced by human male germ cells regulates proliferation and numerous gene expression of Sertoli cells. PMID:26289399

  6. Investigation of the Flow Physics Driving Stall-Side Flutter in Advanced Forward Swept Fan Designs

    NASA Technical Reports Server (NTRS)

    Sanders, Albert J.; Liu, Jong S.; Panovsky, Josef; Bakhle, Milind A.; Stefko, George; Srivastava, Rakesh

    2003-01-01

    Flutter-free operation of advanced transonic fan designs continues to be a challenging task for the designers of aircraft engines. In order to meet the demands of increased performance and lighter weight, these modern fan designs usually feature low-aspect ratio shroudless rotor blade designs that make the task of achieving adequate flutter margin even more challenging for the aeroelastician. This is especially true for advanced forward swept designs that encompass an entirely new design space compared to previous experience. Fortunately, advances in unsteady computational fluid dynamic (CFD) techniques over the past decade now provide an analysis capability that can be used to quantitatively assess the aeroelastic characteristics of these next generation fans during the design cycle. For aeroelastic applications, Mississippi State University and NASA Glenn Research Center have developed the CFD code TURBO-AE. This code is a time-accurate three-dimensional Euler/Navier-Stokes unsteady flow solver developed for axial-flow turbomachinery that can model multiple blade rows undergoing harmonic oscillations with arbitrary interblade phase angles, i.e., nodal diameter patterns. Details of the code can be found in Chen et al. (1993, 1994), Bakhle et al. (1997, 1998), and Srivastava et al. (1999). To assess aeroelastic stability, the work-per-cycle from TURBO-AE is converted to the critical damping ratio since this value is more physically meaningful, with both the unsteady normal pressure and viscous shear forces included in the work-per-cycle calculation. If the total damping (aerodynamic plus mechanical) is negative, then the blade is unstable since it extracts energy from the flow field over the vibration cycle. TURBO-AE is an integral part of an aeroelastic design system being developed at Honeywell Engines, Systems & Services for flutter and forced response predictions, with test cases from development rig and engine tests being used to validate its predictive

  7. Lunar nodal tide and distance to the moon during the Precambrian

    NASA Technical Reports Server (NTRS)

    Walker, J. C. G.; Zahnle, K. J.

    1986-01-01

    The first direct determination of the lunar distance in the Precambrian is presented. A 23.3 + or - 0.3 yr periodicity preserved in 2500 Myr BP Australian banded iron formation is interpreted as reflecting the climatic influence of the lunar nodal tide, which has been detected with its modern 18.6-yr periodicity in some modern climate records. The lunar distance at 2500 Myr BP would then have been about 52 earth radii. The implied history of precambrian tidal friction is in accord with both the more recent paleontological evidence and the long-term stability of the lunar orbit. The length of the Milankovitch cycles that modulate the ice ages today also evolve with the earth-moon system. Their detection in the Precambrian sedimentary record would then permit an independent determination of the lunar distance.

  8. Sick sinus syndrome and atrial fibrillation in older persons - A view from the sinoatrial nodal myocyte.

    PubMed

    Monfredi, O; Boyett, M R

    2015-06-01

    Sick sinus syndrome remains a highly relevant clinical entity, being responsible for the implantation of the majority of electronic pacemakers worldwide. It is an infinitely more complex disease than it was believed when first described in the mid part of the 20th century. It not only involves the innate leading pacemaker region of the heart, the sinoatrial node, but also the atrial myocardium, predisposing to atrial tachydysrhythmias. It remains controversial as to whether the dysfunction of the sinoatrial node directly causes the dysfunction of the atrial myocardium, or vice versa, or indeed whether these two aspects of the condition arise through some related underlying pathological mechanism, such as extracellular matrix remodeling, i.e., fibrosis. This review aims to shed new light on the myriad possible contributing factors in the development of sick sinus syndrome, with a particular focus on the sinoatrial nodal myocyte. This article is part of a Special Issue entitled CV Aging.

  9. Response to Nodal morphogen gradient is determined by the kinetics of target gene induction

    PubMed Central

    Dubrulle, Julien; Jordan, Benjamin M; Akhmetova, Laila; Farrell, Jeffrey A; Kim, Seok-Hyung; Solnica-Krezel, Lilianna; Schier, Alexander F

    2015-01-01

    Morphogen gradients expose cells to different signal concentrations and induce target genes with different ranges of expression. To determine how the Nodal morphogen gradient induces distinct gene expression patterns during zebrafish embryogenesis, we measured the activation dynamics of the signal transducer Smad2 and the expression kinetics of long- and short-range target genes. We found that threshold models based on ligand concentration are insufficient to predict the response of target genes. Instead, morphogen interpretation is shaped by the kinetics of target gene induction: the higher the rate of transcription and the earlier the onset of induction, the greater the spatial range of expression. Thus, the timing and magnitude of target gene expression can be used to modulate the range of expression and diversify the response to morphogen gradients. DOI: http://dx.doi.org/10.7554/eLife.05042.001 PMID:25869585

  10. Unified Theory of PT and CP Invariant Topological Metals and Nodal Superconductors.

    PubMed

    Zhao, Y X; Schnyder, Andreas P; Wang, Z D

    2016-04-15

    As PT and CP symmetries are fundamental in physics, we establish a unified topological theory of PT and CP invariant metals and nodal superconductors, based on the mathematically rigorous KO theory. Representative models are constructed for all nontrivial topological cases in dimensions d=1, 2, and 3, with their exotic physical meanings being elucidated in detail. Intriguingly, it is found that the topological charges of Fermi surfaces in the bulk determine an exotic direction-dependent distribution of topological subgap modes on the boundaries. Furthermore, by constructing an exact bulk-boundary correspondence, we show that the topological Fermi points of the PT and CP invariant classes can appear as gapless modes on the boundary of topological insulators with a certain type of anisotropic crystalline symmetry.

  11. A rare case of extra nodal Rosai-Dorfman disease with isolated multifocal osseous manifestation

    PubMed Central

    Patel, Maharshi H; Jambhekar, Kedar R; Pandey, Tarun; Ram, Roopa

    2015-01-01

    Sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai–Dorfman disease is a non-neoplastic condition which typically presents as massive, bilateral cervical lymphadenopathy and can involve multiple extranodal organ systems such as skin, eyes, and upper respiratory tract in about 28% cases. Bone lesions in association with nodal disease are seen in less than 10% cases. Isolated bone involvement as the only manifestation of SHML is extremely rare, with less than 50 cases reported in the literature. We report a very uncommon case of Rosai–Dorfman disease with isolated multifocal osseous involvement as the only presenting feature, involving about 10 different sites with no lymphadenopathy or other organ system involvement. PMID:26288524

  12. [Dual atrioventricular nodal conduction and arrhythmia with severe hemodynamic alterations during liver retransplantation].

    PubMed

    Zaballos, M; Jimeno, C; Jiménez, C; Fraile, J R; Almendral; García de Lucas, E

    2005-01-01

    We report the case of a man who developed tachycardia caused by atrioventricular reentry related to dual nodal conduction during liver retransplantation. The hemodynamic alterations were severe. Arrhythmia and altered cardiac conduction are potential complications of liver transplantation. The development of tachyarrhythmias--atrial fibrillation as well as episodes of supraventricular and ventricular tachycardia and bradycardia--have been described. Such arrhythmias tend to occur particularly during reperfusion of the graft. Risk factors implicated are the severe ion imbalances, acid-base imbalance, and hypothermia that accompany the reperfusion of a new organ. A review of the possible pathogenic and etiological mechanisms that lead to arrhythmia in patients with end-stage liver disease is provided.

  13. Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe2As2.

    PubMed

    Dong, J K; Zhou, S Y; Guan, T Y; Zhang, H; Dai, Y F; Qiu, X; Wang, X F; He, Y; Chen, X H; Li, S Y

    2010-02-26

    The in-plane resistivity rho and thermal conductivity kappa of the FeAs-based superconductor KFe2As2 single crystal were measured down to 50 mK. We observe non-Fermi-liquid behavior rho(T) approximately T{1.5} at H{c{2}}=5 T, and the development of a Fermi liquid state with rho(T) approximately T{2} when further increasing the field. This suggests a field-induced quantum critical point, occurring at the superconducting upper critical field H{c{2}}. In zero field, there is a large residual linear term kappa{0}/T, and the field dependence of kappa_{0}/T mimics that in d-wave cuprate superconductors. This indicates that the superconducting gaps in KFe2As2 have nodes, likely d-wave symmetry. Such a nodal superconductivity is attributed to the antiferromagnetic spin fluctuations near the quantum critical point.

  14. Nodal gap structure and order parameter symmetry of the unconventional superconductor UPt₃

    DOE PAGES

    Gannon, W. J.; Halperin, W. P.; Rastovski, C.; Schlesinger, K. J.; Hlevyack, J.; Eskildsen, M. R.; Vorontsov, A. B.; Gavilano, J.; Gasser, U.; Nagy, G.

    2015-02-01

    Spanning a broad range of physical systems, complex symmetry breaking is widely recognized as a hallmark of competing interactions. This is exemplified in superfluid ³He which has multiple thermodynamic phases with spin and orbital quantum numbers S = 1 and L = 1, that emerge on cooling from a nearly ferromagnetic Fermi liquid. The heavy fermion compound UPt₃ exhibits similar behavior clearly manifest in its multiple superconducting phases. However, consensus as to its order parameter symmetry has remained elusive. Our small angle neutron scattering measurements indicate a linear temperature dependence of the London penetration depth characteristic of nodal structure ofmore » the order parameter. Our theoretical analysis is consistent with assignment of its symmetry to an L = 3 odd parity state for which one of the three thermodynamic phases in non-zero magnetic field is chiral.« less

  15. Topological semimetals with triply degenerate nodal points in θ -phase tantalum nitride

    NASA Astrophysics Data System (ADS)

    Weng, Hongming; Fang, Chen; Fang, Zhong; Dai, Xi

    2016-06-01

    Using first-principles calculation and symmetry analysis, we propose that θ -TaN is a topological semimetal having a new type of point nodes, i.e., triply degenerate nodal points. Each node is a band crossing between degenerate and nondegenerate bands along the high-symmetry line in the Brillouin zone, and is protected by crystalline symmetries. Such new type of nodes will always generate singular touching points between different Fermi surfaces and three-dimensional spin texture around them. Breaking the crystalline symmetry by external magnetic field or strain leads to various topological phases. By studying the Landau levels under a small field along the c axis, we demonstrate that the system has a new quantum anomaly that we call "helical anomaly.'

  16. Diagnosis of non-nodal paratracheobronchial lesions by linear endobronchial ultrasound.

    PubMed

    Lourido, Tamara; Botana, Maribel; Leiro, Virginia; Núñez, Manuel; Fernández-Villar, Alberto

    2013-08-01

    Linear endobronchial ultrasound (EBUS) allows samples of lesions close to the airways to be obtained, as it enables aspiration to be performed under visual control in real time, opening new possibilities for minimally invasive examination of the mediastinum. While there are many publications on its usefulness in the study of mediastinal or hilar lymphadenopathies, there are few that analyse the role of EBUS-guided transbronchial needle aspiration for the diagnosis of other lesions adjacent to the airways or digestive tract. We describe the characteristics and results obtained in a series of 26 cases of non-nodal lesions of different aetiologies studied by EBUS- guided transbronchial needle aspiration through the airways or oesophagus, demonstrating the usefulness and safety of this technique in the diagnosis of these types of lesions.

  17. The Titan -1:0 Nodal Bending Wave in Saturn's Ring C.

    PubMed

    Rosen, P A; Lissauer, J J

    1988-08-01

    The most prominent oscillatory feature observed in the Voyager 1 radio occultation of Saturn's rings is identified as a one-armed spiral bending wave excited by Titan's -1:0 nodal inner vertical resonance. Ring partides in a bending wave move in coherently inclined orbits, warping the local mean plane of the rings. The Titan -1:0 wave is the only known bending wave that propagates outward, away from Saturn, and the only spiral wave yet observed in which the wave pattern rotates opposite to the orbital direction of the ring particles. It is also the first bending wave identified in ring C. Modeling the observed feature with existing bending wave theory gives a surface mass density of approximately 0.4 g/cm(2) outside the wave region and a local ring thickness of [unknown]5 meters, and suggests that surface mass density is not constant in the wave region.

  18. Increased mesquite gum formation in nodal explants cultures after treatment with a microbial biomass preparation.

    PubMed

    Orozco-Villafuerte, Juan; Buendía-González, Leticia; Cruz-Sosa, Francisco; Vernon-Carter, Eduardo J

    2005-08-01

    Prosopis laevigata nodal explants cultures were established in Murashige and Skoog medium. Simultaneously these cultures were subjected to stress with biotic elicitors and an environmental factor (temperature increase to promote heat stress) in order to promote and increase exuded mesquite gum production. The biotic elicitors were: Aspergillus nidulans and Pseudomonas pseudoalcaligenes both used in concentrations of 10, 20 and 30 mg, whereas the environmental condition was different incubation temperatures (25, 35 and 40 degrees C). The greatest gum production (approximately 13 mg of pooled gum from 100 explants after 14 days incubation) took place when the culture medium was added 10, 20 and 30 mg of autoclaved fungal mycelium of A. nidulans or 30 mg of autoclaved bacterial biomass of P. pseudoalcaligenes in combination with an incubation temperature of 35 degrees C. These treatments were non-significantly different among themselves (P < 0.05), but were significantly different to the rest of the treatments (P > 0.05).

  19. Lunar nodal tide and distance to the moon during the Precambrian

    NASA Astrophysics Data System (ADS)

    Walker, J. C. G.; Zahnle, K. J.

    1986-04-01

    The first direct determination of the lunar distance in the Precambrian is presented. A 23.3 + or - 0.3 yr periodicity preserved in 2500 Myr BP Australian banded iron formation is interpreted as reflecting the climatic influence of the lunar nodal tide, which has been detected with its modern 18.6-yr periodicity in some modern climate records. The lunar distance at 2500 Myr BP would then have been about 52 earth radii. The implied history of precambrian tidal friction is in accord with both the more recent paleontological evidence and the long-term stability of the lunar orbit. The length of the Milankovitch cycles that modulate the ice ages today also evolve with the earth-moon system. Their detection in the Precambrian sedimentary record would then permit an independent determination of the lunar distance.

  20. Analysis of nodal point pollution, variability, and sustainability in mesohaline tidal creeks.

    PubMed

    Muller, Andrew; Muller, Diana

    2014-08-15

    Mesohaline tidal creeks are critical since they may lie at the crossroads of aquatic habitat and urban/sub-urban pressures. The emphasis of this study was to determine the water quality stressor variations within and between tidal creeks and determine whether they serve as nodes of pollutants into the sub-estuary. Measurements of water quality stressors were conducted over a six-year period. The study revealed that characterizing the variability of individual tidal creeks is critical to understanding the process and impacts of stressors in sub-estuarine environments and that the tidal creeks are actually nodal points of sediment and nutrient pollution. This results in hypoxia being controlled within tidal creeks rather than being imported from the parent estuary. The calculated metrics were then used to create a Sustainability Characterization Map. Methods incorporated in this study would be of value to restoration managers, and in the decision-making process of urban and suburban watershed planners.

  1. Nodal gap structure and order parameter symmetry of the unconventional superconductor UPt₃

    SciTech Connect

    Gannon, W. J.; Halperin, W. P.; Rastovski, C.; Schlesinger, K. J.; Hlevyack, J.; Eskildsen, M. R.; Vorontsov, A. B.; Gavilano, J.; Gasser, U.; Nagy, G.

    2015-02-01

    Spanning a broad range of physical systems, complex symmetry breaking is widely recognized as a hallmark of competing interactions. This is exemplified in superfluid ³He which has multiple thermodynamic phases with spin and orbital quantum numbers S = 1 and L = 1, that emerge on cooling from a nearly ferromagnetic Fermi liquid. The heavy fermion compound UPt₃ exhibits similar behavior clearly manifest in its multiple superconducting phases. However, consensus as to its order parameter symmetry has remained elusive. Our small angle neutron scattering measurements indicate a linear temperature dependence of the London penetration depth characteristic of nodal structure of the order parameter. Our theoretical analysis is consistent with assignment of its symmetry to an L = 3 odd parity state for which one of the three thermodynamic phases in non-zero magnetic field is chiral.

  2. Identification and expression of Smads associated with TGF-beta/activin/nodal signaling pathways in the rainbow trout (Oncorhynuchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Smad proteins are essential components of the TGF-beta/activin/nodal family signaling pathway. We report the identification and characterization of transcripts representing 3 receptor Smads (Smad2a, Smad2b, Smad3), 2 common Smads (Smad4a, Smad4b) and one inhibitory Smad (Smad7). Phylogenetic an...

  3. Transcriptomic analysis of Nodal- and BMP-associated genes during juvenile development of the sea urchin Heliocidaris erythrogramma.

    PubMed

    Byrne, Maria; Koop, Demian; Cisternas, Paula; Strbenac, Dario; Yang, Jean Yee Hwa; Wray, Gregory A

    2015-12-01

    Understanding the unusual radial body plan of echinoderms and its relationship to the bilateral plan of other deuterostomes remains a challenge. The molecular processes of embryonic and early larval development in sea urchins are well characterised, but those giving rise to the adult and its radial body remain poorly studied. We used the developmental transcriptome generated for Heliocidaris erythrogramma, a species that forms the juvenile soon after gastrulation, to investigate changes in gene expression underlying radial body development. As coelomogenesis is key to the development of pentamery and juvenile formation on the left side of the larva, we focussed on genes associated with the nodal and BMP2/4 network that pattern this asymmetry. We identified 46 genes associated with this Nodal and BMP2/4 signalling network, and determined their expression profiles from the gastrula, through to rudiment development, metamorphosis and the fully formed juvenile. Genes associated with Nodal signalling shared similar expression profiles, indicating that they may have a regulatory relationship in patterning morphogenesis of the juvenile sea urchin. Similarly, many genes associated with BMP2/4 signalling had similar expression profiles through juvenile development. Further examination of the roles of Nodal- and BMP2/4-associated genes is required to determine function and whether the gene expression profiles seen in H. erythrogramma are due to ongoing activity of gene networks established during early development, or to redeployment of regulatory cassettes to pattern the adult radial body plan.

  4. Nodal signalling in Xenopus: the role of Xnr5 in left/right asymmetry and heart development

    PubMed Central

    Tadjuidje, Emmanuel; Kofron, Matthew; Mir, Adnan; Wylie, Christopher; Heasman, Janet; Cha, Sang-Wook

    2016-01-01

    Nodal class TGF-β signalling molecules play essential roles in establishing the vertebrate body plan. In all vertebrates, nodal family members have specific waves of expression required for tissue specification and axis formation. In Xenopus laevis, six nodal genes are expressed before gastrulation, raising the question of whether they have specific roles or act redundantly with each other. Here, we examine the role of Xnr5. We find it acts at the late blastula stage as a mesoderm inducer and repressor of ectodermal gene expression, a role it shares with Vg1. However, unlike Vg1, Xnr5 depletion reduces the expression of the nodal family member xnr1 at the gastrula stage. It is also required for left/right laterality by controlling the expression of the laterality genes xnr1, antivin (lefty) and pitx2 at the tailbud stage. In Xnr5-depleted embryos, the heart field is established normally, but symmetrical reduction in Xnr5 levels causes a severely stunted midline heart, first evidenced by a reduction in cardiac troponin mRNA levels, while left-sided reduction leads to randomization of the left/right axis. This work identifies Xnr5 as the earliest step in the signalling pathway establishing normal heart laterality in Xenopus. PMID:27488374

  5. Theory of nodal s±-wave pairing symmetry in the Pu-based 115 superconductor family

    PubMed Central

    Das, Tanmoy; Zhu, Jian-Xin; Graf, Matthias J.

    2015-01-01

    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. PMID:25721375

  6. Theory of nodal s±-wave pairing symmetry in the Pu-based 115 superconductor family

    SciTech Connect

    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.

  7. Theory of nodal s±-wave pairing symmetry in the Pu-based 115 superconductor family

    DOE PAGES

    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,more » 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.« less

  8. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  9. Finite elements using absolute nodal coordinates for large-deformation flexible multibody dynamics

    NASA Astrophysics Data System (ADS)

    Dmitrochenko, Oleg

    2008-06-01

    A family of structural finite elements using a modern absolute nodal coordinate formulation (ANCF) is discussed in the paper with many applicationsE This approach has been initiated in 1996 by A. Shabana. It introduces large displacements of 2D/3D finite elements relative to the global reference frame without using any local frame. The elements employ finite slopes as nodal variables and can be considered as generalizations of ordinary finite elements that use infinitesimal slopes. In contrast to other large deformation formulations, the equations of motion contain constant mass matrices and generalized gravity forces as well as zero centrifugal and Coriolis inertia forces. The only nonlinear term is a vector of elastic forces. This approach allows applying known abstractions of real elastic bodies: Euler-Bernoulli beams, Timoshenko beams and more general models as well as Kirchhoff and Mindlin plate theories. Shabana et al. proposed a sub-family of thick beam and plate finite elements with large deformations and employ the 3D theory of continuum mechanics. Despite the universality of such approach it has to use extra degrees of freedom when simulating thin beams and plates, which case is most important. In our research, we propose another sub-family of thin beams as well as rectangular and triangle plates. We use Kirchhoff plate theory with nonlinear strain-displacement relationships to obtain elastic forces. A number of static and dynamic simulation examples of problems with 2D/3D very elastic beams and plate underwent large displacements and/or deformations will be shown in the presentation.

  10. Contactin-1 regulates myelination and nodal/paranodal domain organization in the central nervous system

    PubMed Central

    Çolakoğlu, Gülsen; Bergstrom-Tyrberg, Ulrika; Berglund, Erik O.; Ranscht, Barbara

    2014-01-01

    Myelin, a multilayered membrane sheath formed by oligodendrocytes around axons in the CNS, enables rapid nerve impulse conduction and sustains neuronal health. The signals exchanged between axons and oligodendrocytes in myelin remain to be fully elucidated. Here we provide genetic evidence for multiple and critical functions of Contactin-1 in central myelin. We document dynamic Contactin-1 expression on oligodendrocytes in vivo, and progressive accumulation at nodes of Ranvier and paranodes during postnatal mouse development. Nodal and paranodal expression stabilized in mature myelin, but overall membranous expression diminished. Contactin-1–deficiency disrupted paranodal junction formation as evidenced by loss of Caspr, mislocalized potassium Kv1.2 channels, and abnormal myelin terminal loops. Reduced numbers and impaired maturation of sodium channel clusters accompanied this phenotype. Histological, electron microscopic, and biochemical analyses uncovered significant hypomyelination in Contactin-1–deficient central nerves, with up to 60% myelin loss. Oligodendrocytes were present in normal numbers, albeit a minor population of neuronal/glial antigen 2-positive (NG2+) progenitors lagged in maturation by postnatal day 18, when the mouse null mutation was lethal. Major contributing factors to hypomyelination were defects in the generation and organization of myelin membranes, as judged by electron microscopy and quantitative analysis of oligodendrocyte processes labeled by GFP transgenically expressed from the proteolipid protein promoter. These data reveal that Contactin-1 regulates both myelin formation and organization of nodal and paranodal domains in the CNS. These multiple roles distinguish central Contactin-1 functions from its specific role at paranodes in the periphery, and emphasize mechanistic differences in central and peripheral myelination. PMID:24385581

  11. The Association Between Biological Subtype and Isolated Regional Nodal Failure After Breast-Conserving Therapy

    SciTech Connect

    Wo, Jennifer Y.; Taghian, Alphonse G.; Nguyen, Paul L.; Raad, Rita Abi; Sreedhara, Meera B.A.; Bellon, Jennifer R.; Wong, Julia S.; Gadd, Michele A.; Smith, Barbara L.; Harris, Jay R.

    2010-05-01

    Purpose: To evaluate the risk of isolated regional nodal failure (RNF) among women with invasive breast cancer treated with breast-conserving surgery (BCS) and radiation therapy (RT) and to determine factors, including biological subtype, associated with RNF. Methods and Materials: We retrospectively studied 1,000 consecutive women with invasive breast cancer who received breast-conserving surgery and RT from 1997 through 2002. Ninety percent of patients received adjuvant systemic therapy; none received trastuzumab. Sentinel lymph node biopsy was done in 617 patients (62%). Of patients with one to three positive nodes, 34% received regional nodal irradiation (RNI). Biological subtype classification into luminal A, luminal B, HER-2, and basal subtypes was based on estrogen receptor status-, progesterone receptor status-, and HER-2-status of the primary tumor. Results: Median follow-up was 77 months. Isolated RNF occurred in 6 patients (0.6%). On univariate analysis, biological subtype (p = 0.0002), lymph node involvement (p = 0.008), lymphovascular invasion (p = 0.02), and Grade 3 histology (p = 0.01) were associated with significantly higher RNF rates. Compared with luminal A, the HER-2 (p = 0.01) and basal (p = 0.08) subtypes were associated with higher RNF rates. The 5-year RNF rate among patients with one to three positive nodes treated with tangents alone was 2.4%; we could not identify a subset of these patients with a substantial risk of RNF. Conclusions: Isolated RNF is a rare occurrence after breast-conserving therapy. Patients with the HER-2 (not treated with trastuzumab) and basal subtypes appear to be at higher risk of developing RNF although this risk is not high enough to justify the addition of RNI. Low rates of RNF in patients with one to three positive nodes suggest that tangential RT without RNI is reasonable in most patients.

  12. Debunking the lunar nodal tide in sea level data from the Northwest European shelf

    NASA Astrophysics Data System (ADS)

    Schmith, Torben; Thejll, Peter; Nielsen, Jacob W.

    2016-04-01

    In a recent study (Hansen, et al, 2015. Sea-Level Forcing by Synchronization of 56- and 74-Year Oscillations with the Moon's Nodal Tide on the Northwest European Shelf (Eastern North Sea to Central Baltic Sea). Journal of Coastal Research, 31(5), 1041 - 1056, hereafter 'HAK'), the existence of an 18.6 year lunar nodal tide signal of considerable strength and other periodic signals in the North Sea -- Baltic Sea area is claimed. We criticize important aspects of the analysis presented in HAK and thereby cast doubt on their conclusions. HAK claim that 18.6 year variations in sea level are predicted by tidal theory, but this is not the case in general and therefore the existence of such variations must be explicitly shown. We calculate the amplitude spectrum of the annual sea level by harmonic analysis and find no significant peaks at the periods claimed by HAK. Next, we used the results given by HAK to reconstruct their decomposition, and formed the residuals by subtracting the decomposition from the original data. We found that a strong variability near 18.6 years in the residuals, showing that the decomposition by HAK overrepresents the variability at this period. This motivated us to redo HAK's analysis following their prescription and we found a seven times lower amplitude for the 18.6 year periodicity than claimed by HAK. Finally, we discuss HAK's mode selection-criteria, based on correlation coefficients of trending series and find them invalid. Therefore, we perform a significance test based on a Monte Carlo technique and conclude that none of the modes identified by HAK are statistically significant.

  13. Nodal, paranodal and juxtaparanodal axonal proteins during demyelination and remyelination in multiple sclerosis.

    PubMed

    Coman, I; Aigrot, M S; Seilhean, D; Reynolds, R; Girault, J A; Zalc, B; Lubetzki, C

    2006-12-01

    Saltatory conduction in myelinated fibres depends on the specific molecular organization of highly specialized axonal domains at the node of Ranvier, the paranodal and the juxtaparanodal regions. Voltage-gated sodium channels (Na(v)) have been shown to be deployed along the naked demyelinated axon in experimental models of CNS demyelination and in multiple sclerosis lesions. Little is known about aggregation of nodal, paranodal and juxtaparanodal constituents during the repair process. We analysed by immunohistochemistry on free-floating sections from multiple sclerosis brains the expression and distribution of nodal (Na(v) channels), paranodal (paranodin/Caspr) and juxtaparanodal (K(v) channels and Caspr2) molecules in demyelinated and remyelinated lesions. Whereas in demyelinated lesions, paranodal and juxtaparanodal proteins are diffusely distributed on denuded axons, the distribution of Na(v) channels is heterogeneous, with a diffuse immunoreactivity but also few broad Na(v) channel aggregates in all demyelinated lesions. In contrast to the demyelinated plaques, all remyelinated lesions are characterized by the detection of aggregates of Na(v) channels, paranodin/Caspr, K(v) channels and Caspr2. Our data suggest that these aggregates precede remyelination, and that Na(v) channel aggregation is the initial event, followed by aggregation of paranodal and then juxtaparanodal axonal proteins. Remyelination takes place in multiple sclerosis tissue but myelin repair is often incomplete, and the reasons for this remyelination deficit are many. We suggest that a defect of Na(v) channel aggregation might be involved in the remyelination failure in demyelinated lesions with spared axons and oligodendroglial cells. PMID:16766541

  14. Myelin organization in the nodal, paranodal, and juxtaparanodal regions revealed by scanning x-ray microdiffraction.

    PubMed

    Inouye, Hideyo; Liu, Jiliang; Makowski, Lee; Palmisano, Marilena; Burghammer, Manfred; Riekel, Christian; Kirschner, Daniel A

    2014-01-01

    X-ray diffraction has provided extensive information about the arrangement of lipids and proteins in multilamellar myelin. This information has been limited to the abundant inter-nodal regions of the sheath because these regions dominate the scattering when x-ray beams of 100 µm diameter or more are used. Here, we used a 1 µm beam, raster-scanned across a single nerve fiber, to obtain detailed information about the molecular architecture in the nodal, paranodal, and juxtaparanodal regions. Orientation of the lamellar membrane stacks and membrane periodicity varied spatially. In the juxtaparanode-internode, 198-202 Å-period membrane arrays oriented normal to the nerve fiber axis predominated, whereas in the paranode-node, 205-208 Å-period arrays oriented along the fiber direction predominated. In parts of the sheath distal to the node, multiple sets of lamellar reflections were observed at angles to one another, suggesting that the myelin multilayers are deformed at the Schmidt-Lanterman incisures. The calculated electron density of myelin in the different regions exhibited membrane bilayer profiles with varied electron densities at the polar head groups, likely due to different amounts of major myelin proteins (P0 glycoprotein and myelin basic protein). Scattering from the center of the nerve fibers, where the x-rays are incident en face (perpendicular) to the membrane planes, provided information about the lateral distribution of protein. By underscoring the heterogeneity of membrane packing, microdiffraction analysis suggests a powerful new strategy for understanding the underlying molecular foundation of a broad spectrum of myelinopathies dependent on local specializations of myelin structure in both the PNS and CNS.

  15. Quantum simulation of exotic PT -invariant topological nodal loop bands with ultracold atoms in an optical lattice

    NASA Astrophysics Data System (ADS)

    Zhang, Dan-Wei; Zhao, Y. X.; Liu, Rui-Bin; Xue, Zheng-Yuan; Zhu, Shi-Liang; Wang, Z. D.

    2016-04-01

    Since the well-known PT symmetry has its fundamental significance and implication in physics, where PT denotes a joint operation of space inversion P and time reversal T , it is important and intriguing to explore exotic PT -invariant topological metals and to physically realize them. Here we develop a theory for a different type of topological metals that are described by a two-band model of PT -invariant topological nodal loop states in a three-dimensional Brillouin zone, with the topological stability being revealed through the PT -symmetry-protected nontrivial Z2 topological charge even in the absence of both P and T symmetries. Moreover, the gapless boundary modes are demonstrated to originate from the nontrivial topological charge of the bulk nodal loop. Based on these exact results, we propose an experimental scheme to realize and to detect tunable PT -invariant topological nodal loop states with ultracold atoms in an optical lattice, in which atoms with two hyperfine spin states are loaded in a spin-dependent three-dimensional optical lattice and two pairs of Raman lasers are used to create out-of-plane spin-flip hopping with site-dependent phase. It is shown that such a realistic cold-atom setup can yield topological nodal loop states, having a tunable band-touching ring with the twofold degeneracy in the bulk spectrum and nontrivial surface states. The nodal loop states are actually protected by the combined PT symmetry and are characterized by a Z2-type invariant (or topological charge), i.e., a quantized Berry phase. Remarkably, we demonstrate with numerical simulations that (i) the characteristic nodal ring can be detected by measuring the atomic transfer fractions in a Bloch-Zener oscillation; (ii) the topological invariant may be measured based on the time-of-flight imaging; and (iii) the surface states may be probed through Bragg spectroscopy. The present proposal for realizing topological nodal loop states in cold-atom systems may provide a unique

  16. Discussion on LDPC Codes and Uplink Coding

    NASA Technical Reports Server (NTRS)

    Andrews, Ken; Divsalar, Dariush; Dolinar, Sam; Moision, Bruce; Hamkins, Jon; Pollara, Fabrizio

    2007-01-01

    This slide presentation reviews the progress that the workgroup on Low-Density Parity-Check (LDPC) for space link coding. The workgroup is tasked with developing and recommending new error correcting codes for near-Earth, Lunar, and deep space applications. Included in the presentation is a summary of the technical progress of the workgroup. Charts that show the LDPC decoder sensitivity to symbol scaling errors are reviewed, as well as a chart showing the performance of several frame synchronizer algorithms compared to that of some good codes and LDPC decoder tests at ESTL. Also reviewed is a study on Coding, Modulation, and Link Protocol (CMLP), and the recommended codes. A design for the Pseudo-Randomizer with LDPC Decoder and CRC is also reviewed. A chart that summarizes the three proposed coding systems is also presented.

  17. Vascular endothelial growth factor C complements the ability of positron emission tomography to predict nodal disease in lung cancer

    PubMed Central

    Farjah, Farhood; Madtes, David K.; Wood, Douglas E.; Flum, David R.; Zadworny, Megan E.; Waworuntu, Rachel; Hwang, Billanna; Mulligan, Michael S.

    2016-01-01

    Objective Vascular endothelial growth factors (VEGFs) C and D are biologically rational markers of nodal disease that could improve the accuracy of lung cancer staging. We hypothesized that these biomarkers would improve the ability of positron emission tomography (PET) to predict nodal disease among patients with suspected or confirmed non–small cell lung cancer (NSCLC). Methods A cross-sectional study (2010–2013) was performed of patients prospectively enrolled in a lung nodule biorepository, staged by computed tomography (CT) and PET, and who underwent pathologic nodal evaluation. Enzyme-linked immunosorbent assay was used to measure biomarker levels in plasma from blood drawn before anesthesia. Likelihood ratio testing was used to compare the following logistic regression prediction models: ModelPET, ModelPET/VEGF-C, ModelPET/VEGF-D, and ModelPET/VEGF-C/VEGF-D. To account for 5 planned pairwise comparisons, P values<.01 were considered significant. Results Among 62 patients (median age, 67 years; 48% men; 87% white; and 84% NSCLC), 58% had fluorodeoxyglucose uptake in hilar and/or mediastinal lymph nodes. The prevalence of pathologically confirmed lymph node metastases was 40%. Comparisons of prediction models revealed the following: ModelPET/VEGF-C versus ModelPET (P = .0069), ModelPET/VEGF-D versus ModelPET (P = .1886), ModelPET/VEGF-C/VEGF-D versus ModelPET (P = .0146), ModelPET/VEGF-C/VEGF-D versus ModelPET/VEGF-C (P = .2818), and ModelPET/VEGF-C/VEGF-D versus ModelPET/VEGF-D (P = .0095). In ModelPET/VEGF-C, higher VEGF-C levels were associated with an increased risk of nodal disease (odds ratio, 2.96; 95% confidence interval, 1.26–6.90). Conclusions Plasma levels of VEGF-C complemented the ability of PET to predict nodal disease among patients with suspected or confirmed NSCLC. VEGF-D did not improve prediction. PMID:26320776

  18. On the correct representation of bending and axial deformation in the absolute nodal coordinate formulation with an elastic line approach

    NASA Astrophysics Data System (ADS)

    Gerstmayr, Johannes; Irschik, Hans

    2008-12-01

    In finite element methods that are based on position and slope coordinates, a representation of axial and bending deformation by means of an elastic line approach has become popular. Such beam and plate formulations based on the so-called absolute nodal coordinate formulation have not yet been verified sufficiently enough with respect to analytical results or classical nonlinear rod theories. Examining the existing planar absolute nodal coordinate element, which uses a curvature proportional bending strain expression, it turns out that the deformation does not fully agree with the solution of the geometrically exact theory and, even more serious, the normal force is incorrect. A correction based on the classical ideas of the extensible elastica and geometrically exact theories is applied and a consistent strain energy and bending moment relations are derived. The strain energy of the solid finite element formulation of the absolute nodal coordinate beam is based on the St. Venant-Kirchhoff material: therefore, the strain energy is derived for the latter case and compared to classical nonlinear rod theories. The error in the original absolute nodal coordinate formulation is documented by numerical examples. The numerical example of a large deformation cantilever beam shows that the normal force is incorrect when using the previous approach, while a perfect agreement between the absolute nodal coordinate formulation and the extensible elastica can be gained when applying the proposed modifications. The numerical examples show a very good agreement of reference analytical and numerical solutions with the solutions of the proposed beam formulation for the case of large deformation pre-curved static and dynamic problems, including buckling and eigenvalue analysis. The resulting beam formulation does not employ rotational degrees of freedom and therefore has advantages compared to classical beam elements regarding energy-momentum conservation.

  19. Polymorphisms in MMP9 and SIPA1 are associated with increased risk of nodal metastases in early stage cervical cancer

    PubMed Central

    Brooks, Rebecca; Kizer, Nora; Nguyen, Loan; Jaishuen, Atthapon; Wanat, Karolyn; Nugent, Elizabeth; Grigsby, Perry; Allsworth, Jenifer E.; Rader, Janet S.

    2009-01-01

    Objective Heritable polymorphisms modulate metastatic efficiency in cancer. Single nucleotide polymorphisms (SNPs) in MMP9 (rs17576) and SIPA1 (rs746429, rs931127) have been associated with nodal metastases in multiple cancers. We investigated the association of these SNPs with nodal metastases in early stage cervical cancer. Methods Consecutive patients with stage IB cervical cancer who underwent a pelvic lymph node (LN) dissection were included. Cases (≥ 1 positive LN, n=101) were compared with controls (negative LN pathology, n=273). Genotyping was performed on genomic DNA in the 3 SNPs using a Taqman assay, and correlated with clinical variables. Results The G allele at SIPA1 rs931127 was associated with an increased risk of nodal disease (OR 1.9, p=0.03), and approached significance at SIPA 1 rs746429 (OR 2.2, p=0.09) and MMP9 rs17576 (OR 1.5, 0.08). In patients with stage Ib1 lesions (n=304), the G allele at both SIPA1 SNPs were associated with LN metastases (rs746429 OR 10.1, p=0.01; rs931127 OR 2.4, p=0.01). In patients with no lymph vascular space invasion, SIPA1 SNPs were again associated with LN metastases, and all patients with nodal disease had at least one G allele at SIPA1 rs746429. Conclusions In this case control study, SNPs in SIPA1 varied statistically in cervical cancer patients with and without nodal metastases, and in MMP9 after controlling for stage and lymphvascular space invasion. Further work is needed to characterize inherited polymorphisms that provide a permissive background for the metastatic cascade. PMID:19906411

  20. Impact of FDG-PET/CT Imaging on Nodal Staging for Head-And-Neck Squamous Cell Carcinoma

    SciTech Connect

    Murakami, Ryuji . E-mail: murakami@kaiju.medic.kumamoto-u.ac.jp; Uozumi, Hideaki; Hirai, Toshinori; Nishimura, Ryuichi; Shiraishi, Shinya; Ota, Kazutoshi D.D.S.; Murakami, Daizo; Tomiguchi, Seiji; Oya, Natsuo; Katsuragawa, Shigehiko; Yamashita, Yasuyuki

    2007-06-01

    Purpose: To evaluate the impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging on nodal staging for head-and-neck squamous cell carcinoma (SCC). Methods and Materials: The study population consisted of 23 patients with head-and-neck SCC who were evaluated with FDG-PET/CT and went on to neck dissection. Two observers consensually determined the lesion size and maximum standardized uptake value (SUV{sub max}) and compared the results with pathologic findings on nodal-level involvement. Two different observers (A and B) independently performed three protocols for clinical nodal staging. Methods 1, 2, and 3 were based on conventional modalities, additional visual information from FDG-PET/CT images, and FDG-PET/CT imaging alone with SUV data, respectively. Results: All primary tumors were visualized with FDG-PET/CT. Pathologically, 19 positive and 93 negative nodal levels were identified. The SUV{sub max} overlapped in negative and positive nodes <15 mm in diameter. According to receiver operating characteristics analysis, the size-based SUV{sub max} cutoff values were 1.9, 2.5, and 3.0 for lymph nodes <10 mm, 10-15 mm, and >15 mm, respectively. These cutoff values yielded 79% sensitivity and 99% specificity for nodal-level staging. For Observer A, the sensitivity and specificity in Methods 1, 2, and 3 were 68% and 94%, 68% and 99%, and 84% and 99%, respectively, and Method 3 yielded significantly higher accuracy than Method 1 (p = 0.0269). For Observer B, Method 3 yielded the highest sensitivity (84%) and specificity (99%); however, the difference among the three protocols was not statistically significant. Conclusion: Imaging with FDG-PET/CT with size-based SUV{sub max} cutoff values is an important modality for radiation therapy planning.

  1. Nodal endoplasmic reticulum, a specialized form of endoplasmic reticulum found in gravity-sensing root tip columella cells

    NASA Technical Reports Server (NTRS)

    Zheng, H. Q.; Staehelin, L. A.

    2001-01-01

    The endoplasmic reticulum (ER) of columella root cap cells has been postulated to play a role in gravity sensing. We have re-examined the ultrastructure of columella cells in tobacco (Nicotiana tabacum) root tips preserved by high-pressure freezing/freeze-substitution techniques to gain more precise information about the organization of the ER in such cells. The most notable findings are: the identification of a specialized form of ER, termed "nodal ER," which is found exclusively in columella cells; the demonstration that the bulk of the ER is organized in the form of a tubular network that is confined to a peripheral layer under the plasma membrane; and the discovery that this ER-rich peripheral region excludes Golgi stacks, vacuoles, and amyloplasts but not mitochondria. Nodal ER domains consist of an approximately 100-nm-diameter central rod composed of oblong subunits to which usually seven sheets of rough ER are attached along their margins. These domains form patches at the interface between the peripheral ER network and the ER-free central region of the cells, and they occupy defined positions within central and flanking columella cells. Over one-half of the nodal ER domains are located along the outer tangential walls of the flanking cells. Cytochalasin D and latrunculin A cause an increase in size and a decrease in numbers of nodal ER domains. We postulate that the nodal ER membranes locally modulate the gravisensing signals produced by the sedimenting amyloplasts, and that the confinement of all ER membranes to the cell periphery serves to enhance the sedimentability of the amyloplasts in the central region of columella cells.

  2. BMP Inhibition in Seminomas Initiates Acquisition of Pluripotency via NODAL Signaling Resulting in Reprogramming to an Embryonal Carcinoma

    PubMed Central

    Nettersheim, Daniel; Jostes, Sina; Sharma, Rakesh; Schneider, Simon; Hofmann, Andrea; Ferreira, Humberto J.; Hoffmann, Per; Kristiansen, Glen; Esteller, Manel B.; Schorle, Hubert

    2015-01-01

    Type II germ cell cancers (GCC) can be subdivided into seminomas and non-seminomas. Seminomas are similar to carcinoma in situ (CIS) cells, the common precursor of type II GCCs, with regard to epigenetics and expression, while embryonal carcinomas (EC) are totipotent and differentiate into teratomas, yolk-sac tumors and choriocarcinomas. GCCs can present as seminomas with a non-seminoma component, raising the question if a CIS gives rise to seminomas and ECs at the same time or whether seminomas can be reprogrammed to ECs. In this study, we utilized the seminoma cell line TCam-2 that acquires an EC-like status after xenografting into the murine flank as a model for a seminoma to EC transition and screened for factors initiating and driving this process. Analysis of expression and DNA methylation dynamics during transition of TCam-2 revealed that many pluripotency- and reprogramming-associated genes were upregulated while seminoma-markers were downregulated. Changes in expression level of 53 genes inversely correlated to changes in DNA methylation. Interestingly, after xenotransplantation 6 genes (GDF3, NODAL, DNMT3B, DPPA3, GAL, AK3L1) were rapidly induced, followed by demethylation of their genomic loci, suggesting that these 6 genes are poised for expression driving the reprogramming. We demonstrate that inhibition of BMP signaling is the initial event in reprogramming, resulting in activation of the pluripotency-associated genes and NODAL signaling. We propose that reprogramming of seminomas to ECs is a multi-step process. Initially, the microenvironment causes inhibition of BMP signaling, leading to induction of NODAL signaling. During a maturation phase, a fast acting NODAL loop stimulates its own activity and temporarily inhibits BMP signaling. During the stabilization phase, a slow acting NODAL loop, involving WNTs re-establishes BMP signaling and the pluripotency circuitry. In parallel, DNMT3B-driven de novo methylation silences seminoma-associated genes

  3. Incidental Nodal Lymphangioleiomyomatosis Is Not a Harbinger of Pulmonary Lymphangioleiomyomatosis: A Study of 19 Cases with Evaluation of Diagnostic Immunohistochemistry

    PubMed Central

    Schoolmeester, J. Kenneth; Park, Kay J.

    2016-01-01

    Lymphangioleiomyomatosis (LAM) is a proliferation of perivascular epithelioid cells typically affecting the lung as a low grade, destructive and progressive disease, but may also be found in lymph nodes and other organs. LAM is sometimes seen as an incidental finding in lymph node dissections performed for staging of gynecologic tumors. To our knowledge, no study has investigated the clinical significance of incidental nodal LAM in relation to subsequent development of pulmonary LAM. We identified 19 patients from our institution with LAM in lymph nodes. Follow up was available for 100% of patients and ranged from 3 to 123 months (mean 33.8 months). All were women and ages ranged from 35 to 71 years (mean 56.3). None had a history of tuberous sclerosis, renal angiomyolipoma or pulmonary LAM. LAM involvement spanned 1 to 6 nodes (mean 2) ranging from 1 to 100% of the total excised lymph nodes. The single largest focus of nodal LAM ranged from 1 to 9 mm (mean 4.3) in 18 patients without evidence of persistent or recurrent nodal LAM. In the one patient with persistent local nodal LAM, the greatest diameter was 25 mm. Affected lymph node sites were regional pelvic and retroperitoneal chains routinely sampled in staging operations. An immunohisotchemical panel of HMB45, A103 and β-catenin was evaluated in 18 cases. HMB45 showed strong, but usually focal staining in every case compared to A103 which was very focally expressed (39%) or negative. β-catenin showed strong, diffuse cytoplasmic and membranous (nonnuclear) reactivity in 100% of cases. At last clinic visit, all 19 patients had no manifestations of pulmonary LAM. In an absence of signs of symptoms of extranodal LAM, patients with incidentally discovered nodal LAM smaller than 10 mm are not at risk for developing pulmonary LAM. PMID:26135558

  4. Manually operated coded switch

    DOEpatents

    Barnette, Jon H.

    1978-01-01

    The disclosure relates to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made.

  5. Parafermion stabilizer codes

    NASA Astrophysics Data System (ADS)

    Güngördü, Utkan; Nepal, Rabindra; Kovalev, Alexey A.

    2014-10-01

    We define and study parafermion stabilizer codes, which can be viewed as generalizations of Kitaev's one-dimensional (1D) model of unpaired Majorana fermions. Parafermion stabilizer codes can protect against low-weight errors acting on a small subset of parafermion modes in analogy to qudit stabilizer codes. Examples of several smallest parafermion stabilizer codes are given. A locality-preserving embedding of qudit operators into parafermion operators is established that allows one to map known qudit stabilizer codes to parafermion codes. We also present a local 2D parafermion construction that combines topological protection of Kitaev's toric code with additional protection relying on parity conservation.

  6. ARA type protograph codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2008-01-01

    An apparatus and method for encoding low-density parity check codes. Together with a repeater, an interleaver and an accumulator, the apparatus comprises a precoder, thus forming accumulate-repeat-accumulate (ARA codes). Protographs representing various types of ARA codes, including AR3A, AR4A and ARJA codes, are described. High performance is obtained when compared to the performance of current repeat-accumulate (RA) or irregular-repeat-accumulate (IRA) codes.

  7. QR Codes 101

    ERIC Educational Resources Information Center

    Crompton, Helen; LaFrance, Jason; van 't Hooft, Mark

    2012-01-01

    A QR (quick-response) code is a two-dimensional scannable code, similar in function to a traditional bar code that one might find on a product at the supermarket. The main difference between the two is that, while a traditional bar code can hold a maximum of only 20 digits, a QR code can hold up to 7,089 characters, so it can contain much more…

  8. Overview of Recent Radiation Transport Code Comparisons for Space Applications

    NASA Astrophysics Data System (ADS)

    Townsend, Lawrence

    Recent advances in radiation transport code development for space applications have resulted in various comparisons of code predictions for a variety of scenarios and codes. Comparisons among both Monte Carlo and deterministic codes have been made and published by vari-ous groups and collaborations, including comparisons involving, but not limited to HZETRN, HETC-HEDS, FLUKA, GEANT, PHITS, and MCNPX. In this work, an overview of recent code prediction inter-comparisons, including comparisons to available experimental data, is presented and discussed, with emphases on those areas of agreement and disagreement among the various code predictions and published data.

  9. SCDAP/RELAP5/MOD 3.1 Code Manual: Developmental assessment. Volume 5

    SciTech Connect

    Hohorst, J.K.; Johnsen, E.C.; Allison, C.M.

    1995-06-01

    The SCDAP/RELAP5 code has been developed for best estimate transient simulation of Light Water Reactor coolant systems during a severe accident. The code models the coupled behavior of the reactor coolant system, the core, fission product released during a severe accident transient as well as large and small break loss of coolant accidents, operational transients such as anticipated transient without SCRAM, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater conditioning systems. This volume contains detailed code-to-data calculations performed using SCDAP/RELAP5/MOD3.1, as well as comparison calculations performed with earlier code versions. Results of full plant calculations which include Surry, TMI-2, and Browns Ferry are described. Results of a nodalization study, which accounted for both axial and radial nodalization of the core, are also reported.

  10. Advanced Electrophysiologic Mapping Systems

    PubMed Central

    2006-01-01

    has not been found to be effective for the treatment of complex arrhythmias such as chronic atrial fibrillation or ventricular tachycardia. Advanced nonfluoroscopic mapping systems have been developed for guiding the ablation of these complex arrhythmias. The Technology Four nonfluoroscopic advanced mapping systems have been licensed by Health Canada: CARTO EP mapping System (manufactured by Biosense Webster, CA) uses weak magnetic fields and a special mapping/ablation catheter with a magnetic sensor to locate the catheter and reconstruct a 3-dimensional geometry of the heart superimposed with colour-coded electric potential maps to guide ablation. EnSite System (manufactured by Endocardial Solutions Inc., MN) includes a multi-electrode non-contact catheter that conducts simultaneous mapping. A processing unit uses the electrical data to computes more than 3,000 isopotential electrograms that are displayed on a reconstructed 3-dimensional geometry of the heart chamber. The navigational system, EnSite NavX, can be used separately with most mapping catheters. The LocaLisa Intracardiac System (manufactured by Medtronics Inc, MN) is a navigational system that uses an electrical field to locate the mapping catheter. It reconstructs the location of the electrodes on the mapping catheter in 3-dimensional virtual space, thereby enabling an ablation catheter to be directed to the electrode that identifies abnormal electric potential. Polar Constellation Advanced Mapping Catheter System (manufactured by Boston Scientific, MA) is a multielectrode basket catheter with 64 electrodes on 8 splines. Once deployed, each electrode is automatically traced. The information enables a 3-dimensional model of the basket catheter to be computed. Colour-coded activation maps are reconstructed online and displayed on a monitor. By using this catheter, a precise electrical map of the atrium can be obtained in several heartbeats. Review Strategy A systematic search of Cochrane, MEDLINE and EMBASE

  11. Patterns of nodal relapse after surgery and postoperative radiation therapy for carcinomas of the major and minor salivary glands: What is the role of elective neck irradiation?

    SciTech Connect

    Chen, Allen M. . E-mail: allenmchen@yahoo.com; Garcia, Joaquin; Lee, Nancy Y.; Bucci, M. Kara; Eisele, David W.

    2007-03-15

    Purpose: To evaluate the incidence of nodal relapses from carcinomas of the salivary glands among patients with clinically negative necks in an attempt to determine the potential utility of elective neck irradiation (ENI). Methods and Materials: Between 1960 and 2004, 251 patients with clinically N0 carcinomas of the salivary glands were treated with surgery and postoperative radiation therapy. None of the patients had undergone previous neck dissection. Histology was: adenoid cystic (84 patients), mucoepidermoid (60 patients), adenocarcinoma (58 patients), acinic cell (21 patients), undifferentiated (11 patients), carcinoma ex pleomorphic adenoma (7 patients), squamous cell (7 patients), and salivary duct carcinoma (3 patients); 131 patients (52%) had ENI. Median follow-up was 62 months (range, 3-267 months). Results: The 5- and 10-year actuarial estimates of nodal relapse were 11% and 13%, respectively. The 10-year actuarial rates of nodal failure were 7%, 5%, 12%, and 16%, for patients with T1, T2, T3, and T4 disease, respectively (p = 0.11). The use of ENI reduced the 10-year nodal failure rate from 26% to 0% (p = 0.0001). The highest crude rates of nodal relapse among those treated without ENI were found in patients with squamous cell carcinoma (67%), undifferentiated carcinoma (50%), adenocarcinoma (34%), and mucoepidermoid carcinoma (29%). There were no nodal failures observed among patients with adenoid cystic or acinic cell histology. Conclusion: ENI effectively prevents nodal relapses and should be used for select patients at high risk for regional failure.

  12. Graded Nodal/Activin Signaling Titrates Conversion of Quantitative Phospho-Smad2 Levels into Qualitative Embryonic Stem Cell Fate Decisions

    PubMed Central

    Orlov, Yuriy Lvovich; Yit, Le Yau; Yang, Henry; Ang, Lay Teng; Poellinger, Lorenz; Lim, Bing

    2011-01-01

    Nodal and Activin are morphogens of the TGFbeta superfamily of signaling molecules that direct differential cell fate decisions in a dose- and distance-dependent manner. During early embryonic development the Nodal/Activin pathway is responsible for the specification of mesoderm, endoderm, node, and mesendoderm. In contradiction to this drive towards cellular differentiation, the pathway also plays important roles in the maintenance of self-renewal and pluripotency in embryonic and epiblast stem cells. The molecular basis behind stem cell interpretation of Nodal/Activin signaling gradients and the undertaking of disparate cell fate decisions remains poorly understood. Here, we show that any perturbation of endogenous signaling levels in mouse embryonic stem cells leads to their exit from self-renewal towards divergent differentiation programs. Increasing Nodal signals above basal levels by direct stimulation with Activin promotes differentiation towards the mesendodermal lineages while repression of signaling with the specific Nodal/Activin receptor inhibitor SB431542 induces trophectodermal differentiation. To address how quantitative Nodal/Activin signals are translated qualitatively into distinct cell fates decisions, we performed chromatin immunoprecipitation of phospho-Smad2, the primary downstream transcriptional factor of the Nodal/Activin pathway, followed by massively parallel sequencing, and show that phospho-Smad2 binds to and regulates distinct subsets of target genes in a dose-dependent manner. Crucially, Nodal/Activin signaling directly controls the Oct4 master regulator of pluripotency by graded phospho-Smad2 binding in the promoter region. Hence stem cells interpret and carry out differential Nodal/Activin signaling instructions via a corresponding gradient of Smad2 phosphorylation that selectively titrates self-renewal against alternative differentiation programs by direct regulation of distinct target gene subsets and Oct4 expression. PMID

  13. Role of Ultrasonography of Regional Nodal Basins in Staging Triple-Negative Breast Cancer and Implications For Local-Regional Treatment

    SciTech Connect

    Shaitelman, Simona F.; Tereffe, Welela; Dogan, Basak E.; Hess, Kenneth R.; Caudle, Abigail S.; Valero, Vicente; Stauder, Michael C.; Krishnamurthy, Savitri; Candelaria, Rosalind P.; Strom, Eric A.; Woodward, Wendy A.; Hunt, Kelly K.; Buchholz, Thomas A.; Whitman, Gary J.

    2015-09-01

    Purpose: We sought to determine the rate at which regional nodal ultrasonography would increase the nodal disease stage in patients with triple-negative breast cancer (TNBC) beyond the clinical stage determined by physical examination and mammography alone, and significantly affect the treatments delivered to these patients. Methods and Materials: We retrospectively reviewed the charts of women with stages I to III TNBC who underwent physical examination, mammography, breast and regional nodal ultrasonography with needle biopsy of abnormal nodes, and definitive local-regional treatment at our institution between 2004 and 2011. The stages of these patients' disease with and without ultrasonography of the regional nodal basins were compared using the Pearson χ{sup 2} test. Definitive treatments of patients whose nodal disease was upstaged on the basis of ultrasonographic findings were compared to those of patients whose disease stage remained the same. Results: A total of 572 women met the study requirements. In 111 (19.4%) of these patients, regional nodal ultrasonography with needle biopsy resulted in an increase in disease stage from the original stage by physical examination and mammography alone. Significantly higher percentages of patients whose nodal disease was upstaged by ultrasonographic findings compared to that in patients whose disease was not upstaged underwent neoadjuvant systemic therapy (91.9% and 51.2%, respectively; P<.0001), axillary lymph node dissection (99.1% and 34.5%, respectively; P<.0001), and radiation to the regional nodal basins (88.2% and 29.1%, respectively; P<.0001). Conclusions: Regional nodal ultrasonography in TNBC frequently changes the initial clinical stage and plays an important role in treatment planning.

  14. Nonbinary Quantum Convolutional Codes Derived from Negacyclic Codes

    NASA Astrophysics Data System (ADS)

    Chen, Jianzhang; Li, Jianping; Yang, Fan; Huang, Yuanyuan

    2015-01-01

    In this paper, some families of nonbinary quantum convolutional codes are constructed by using negacyclic codes. These nonbinary quantum convolutional codes are different from quantum convolutional codes in the literature. Moreover, we construct a family of optimal quantum convolutional codes.

  15. Liquid rocket combustor computer code development

    NASA Technical Reports Server (NTRS)

    Liang, P. Y.

    1985-01-01

    The Advanced Rocket Injector/Combustor Code (ARICC) that has been developed to model the complete chemical/fluid/thermal processes occurring inside rocket combustion chambers are highlighted. The code, derived from the CONCHAS-SPRAY code originally developed at Los Alamos National Laboratory incorporates powerful features such as the ability to model complex injector combustion chamber geometries, Lagrangian tracking of droplets, full chemical equilibrium and kinetic reactions for multiple species, a fractional volume of fluid (VOF) description of liquid jet injection in addition to the gaseous phase fluid dynamics, and turbulent mass, energy, and momentum transport. Atomization and droplet dynamic models from earlier generation codes are transplated into the present code. Currently, ARICC is specialized for liquid oxygen/hydrogen propellants, although other fuel/oxidizer pairs can be easily substituted.

  16. Utility of QR codes in biological collections

    PubMed Central

    Diazgranados, Mauricio; Funk, Vicki A.

    2013-01-01

    Abstract The popularity of QR codes for encoding information such as URIs has increased exponentially in step with the technological advances and availability of smartphones, digital tablets, and other electronic devices. We propose using QR codes on specimens in biological collections to facilitate linking vouchers’ electronic information with their associated collections. QR codes can efficiently provide such links for connecting collections, photographs, maps, ecosystem notes, citations, and even GenBank sequences. QR codes have numerous advantages over barcodes, including their small size, superior security mechanisms, increased complexity and quantity of information, and low implementation cost. The scope of this paper is to initiate an academic discussion about using QR codes on specimens in biological collections. PMID:24198709

  17. Emergent loop-nodal s(±)-wave superconductivity in CeCu(2)Si(2): similarities to the iron-based superconductors.

    PubMed

    Ikeda, Hiroaki; Suzuki, Michi-To; Arita, Ryotaro

    2015-04-10

    Heavy-fermion superconductors are prime candidates for novel electron-pairing states due to the spin-orbital coupled degrees of freedom and electron correlations. Superconductivity in CeCu_{2}Si_{2} discovered in 1979, which is a prototype of unconventional (non-BCS) superconductors in strongly correlated electron systems, still remains unsolved. Here we provide the first report of superconductivity based on the advanced first-principles theoretical approach. We find that the promising candidate is an s_{±}-wave state with loop-shaped nodes on the Fermi surface, different from the widely expected line-nodal d-wave state. The dominant pairing glue is magnetic but high-rank octupole fluctuations. This system shares the importance of multiorbital degrees of freedom with the iron-based superconductors. Our findings reveal not only the long-standing puzzle in this material, but also urge us to reconsider the pairing states and mechanisms in all heavy-fermion superconductors. PMID:25910154

  18. Asymmetric quantum convolutional codes

    NASA Astrophysics Data System (ADS)

    La Guardia, Giuliano G.

    2016-01-01

    In this paper, we construct the first families of asymmetric quantum convolutional codes (AQCCs). These new AQCCs are constructed by means of the CSS-type construction applied to suitable families of classical convolutional codes, which are also constructed here. The new codes have non-catastrophic generator matrices, and they have great asymmetry. Since our constructions are performed algebraically, i.e. we develop general algebraic methods and properties to perform the constructions, it is possible to derive several families of such codes and not only codes with specific parameters. Additionally, several different types of such codes are obtained.

  19. Evaluation of discrepancies in assembly cross-section generator codes

    SciTech Connect

    Fisher, J.R.; Grow, R.L.; Rapp, J.S.; Smolinske, K.M.; Mint, L.S. )

    1990-02-01

    The capabilities of utility reactor analysis technical staffs have increased significantly over the past five to ten years. Utilities utilize different cross section generators (EPRI-CELL, CPM, CASMO), different versions of these generators and different libraries in the generators, to produce input to different nodal codes. Phase I of this project utilized available data from utility calculations to identify the areas of differences in calculated results and to make an initial assessment of the potential impact and/or consequence of these differences. Phase II of this project investigated these differences via a consortium of utilities performing calculations for pin cells and multi-pin cells using controlled input data and options. The Phase II goal was to quantify differences and to determine if the differences were due to cross section library, cross section code methodology or the procedure for utilizing a code. The Phase III goal was to investigate the significant differences from Phase II in an assembly environment to determine if the differences became smaller, larger or remained the same in the assembly environment. The Phase III assembly calculations were performed by the same group of utilities as Phase II and the cases used controlled input and code vendor input option recommendations. 10 figs., 31 tabs.

  20. Development of a parallelization strategy for the VARIANT code

    SciTech Connect

    Hanebutte, U.R.; Khalil, H.S.; Palmiotti, G.; Tatsumi, M.

    1996-12-31

    The VARIANT code solves the multigroup steady-state neutron diffusion and transport equation in three-dimensional Cartesian and hexagonal geometries using the variational nodal method. VARIANT consists of four major parts that must be executed sequentially: input handling, calculation of response matrices, solution algorithm (i.e. inner-outer iteration), and output of results. The objective of the parallelization effort was to reduce the overall computing time by distributing the work of the two computationally intensive (sequential) tasks, the coupling coefficient calculation and the iterative solver, equally among a group of processors. This report describes the code`s calculations and gives performance results on one of the benchmark problems used to test the code. The performance analysis in the IBM SPx system shows good efficiency for well-load-balanced programs. Even for relatively small problem sizes, respectable efficiencies are seen for the SPx. An extension to achieve a higher degree of parallelism will be addressed in future work. 7 refs., 1 tab.

  1. RTE: A computer code for Rocket Thermal Evaluation

    NASA Technical Reports Server (NTRS)

    Naraghi, Mohammad H. N.

    1995-01-01

    The numerical model for a rocket thermal analysis code (RTE) is discussed. RTE is a comprehensive thermal analysis code for thermal analysis of regeneratively cooled rocket engines. The input to the code consists of the composition of fuel/oxidant mixture and flow rates, chamber pressure, coolant temperature and pressure. dimensions of the engine, materials and the number of nodes in different parts of the engine. The code allows for temperature variation in axial, radial and circumferential directions. By implementing an iterative scheme, it provides nodal temperature distribution, rates of heat transfer, hot gas and coolant thermal and transport properties. The fuel/oxidant mixture ratio can be varied along the thrust chamber. This feature allows the user to incorporate a non-equilibrium model or an energy release model for the hot-gas-side. The user has the option of bypassing the hot-gas-side calculations and directly inputting the gas-side fluxes. This feature is used to link RTE to a boundary layer module for the hot-gas-side heat flux calculations.

  2. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-02-20

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  3. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-01-01

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  4. QR Code Mania!

    ERIC Educational Resources Information Center

    Shumack, Kellie A.; Reilly, Erin; Chamberlain, Nik

    2013-01-01

    space, has error-correction capacity, and can be read from any direction. These codes are used in manufacturing, shipping, and marketing, as well as in education. QR codes can be created to produce…

  5. Programming and Isolation of Highly Pure Physiologically and Pharmacologically Functional Sinus-Nodal Bodies from Pluripotent Stem Cells

    PubMed Central

    Jung, Julia Jeannine; Husse, Britta; Rimmbach, Christian; Krebs, Stefan; Stieber, Juliane; Steinhoff, Gustav; Dendorfer, Andreas; Franz, Wolfgang-Michael; David, Robert

    2014-01-01

    Summary Therapeutic approaches for “sick sinus syndrome” rely on electrical pacemakers, which lack hormone responsiveness and bear hazards such as infection and battery failure. These issues may be overcome via “biological pacemakers” derived from pluripotent stem cells (PSCs). Here, we show that forward programming of PSCs with the nodal cell inducer TBX3 plus an additional Myh6-promoter-based antibiotic selection leads to cardiomyocyte aggregates consisting of >80% physiologically and pharmacologically functional pacemaker cells. These induced sinoatrial bodies (iSABs) exhibited highly increased beating rates (300–400 bpm), coming close to those found in mouse hearts, and were able to robustly pace myocardium ex vivo. Our study introduces iSABs as highly pure, functional nodal tissue that is derived from PSCs and may be important for future cell therapies and drug testing in vitro. PMID:24936448

  6. Nodal-line pairing with 1D-3D coupled Fermi surfaces: A model motivated by Cr-based superconductors

    NASA Astrophysics Data System (ADS)

    Wachtel, Gideon; Kim, Yong Baek

    2016-09-01

    Motivated by the recent discovery of a new family of chromium-based superconductors, we consider a two-band model, where a band of electrons dispersing only in one direction interacts with a band of electrons dispersing in all three directions. Strong 2 kf density fluctuations in the one-dimensional band induces attractive interactions between the three-dimensional electrons, which, in turn, makes the system superconducting. Solving the associated Eliashberg equations, we obtain a gap function which is peaked at the "poles" of the three-dimensional Fermi sphere, and decreases towards the "equator." When strong enough local repulsion is included, the gap actually changes sign around the equator and nodal rings are formed. These nodal rings manifest themselves in several experimentally observable quantities, some of which resemble unconventional observations in the newly discovered superconductors which motivated this work.

  7. Unusual presentation of Warthin variant of Papillary thyroid carcinoma with lymph nodal metastases in a patient of Graves' disease.

    PubMed

    Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga; Arun, B R

    2015-01-01

    Warthin-like Papillary thyroid carcinoma (WPTC) is a rare variant of papillary carcinoma of thyroid, PTC which derives its name by closely resembling Warthin's tumor of salivary gland. Hallmark histological feature of this variant is papillary folding lined by oncocytic neoplastic cells with clear nuclei and nuclear pseudoinclusions, accompanied by prominent lymphocytic infiltrate in the papillary stalks. It is thought to be one of those differentiated thyroid cancers with favorable prognosis. We report a case of Graves' disease with a cold nodule harboring WPTC with initial presentation of lymph nodal metastases. It is important to identify this peculiar variant of PTC as 5 to 10% of them undergo dedifferentiation and 30% have the lymph nodal metastases and extra thyroidal extension.

  8. Exactly solvable spin-1 Ising-Heisenberg diamond chain with the second-neighbor interaction between nodal spins.

    PubMed

    Hovhannisyan, V V; Strečka, J; Ananikian, N S

    2016-03-01

    The spin-1 Ising-Heisenberg diamond chain with the second-neighbor interaction between nodal spins is rigorously solved using the transfer-matrix method. In particular, exact results for the ground state, magnetization process and specific heat are presented and discussed. It is shown that further-neighbor interaction between nodal spins gives rise to three novel ground states with a translationally broken symmetry, but at the same time, does not increases the total number of intermediate plateaus in a zero-temperature magnetization curve compared with the simplified model without this interaction term. The zero-field specific heat displays interesting thermal dependencies with a single- or double-peak structure. PMID:26836749

  9. The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions.

    PubMed

    Low, Jennifer E; Åslund, Melissa L Whitfield; Rutter, Allison; Zeeb, Barbara A

    2011-03-01

    Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 μg g(-1)). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time.

  10. Exactly solvable spin-1 Ising-Heisenberg diamond chain with the second-neighbor interaction between nodal spins

    NASA Astrophysics Data System (ADS)

    Hovhannisyan, V. V.; Strečka, J.; Ananikian, N. S.

    2016-03-01

    The spin-1 Ising-Heisenberg diamond chain with the second-neighbor interaction between nodal spins is rigorously solved using the transfer-matrix method. In particular, exact results for the ground state, magnetization process and specific heat are presented and discussed. It is shown that further-neighbor interaction between nodal spins gives rise to three novel ground states with a translationally broken symmetry, but at the same time, does not increases the total number of intermediate plateaus in a zero-temperature magnetization curve compared with the simplified model without this interaction term. The zero-field specific heat displays interesting thermal dependencies with a single- or double-peak structure.

  11. EMF wire code research

    SciTech Connect

    Jones, T.

    1993-11-01

    This paper examines the results of previous wire code research to determines the relationship with childhood cancer, wire codes and electromagnetic fields. The paper suggests that, in the original Savitz study, biases toward producing a false positive association between high wire codes and childhood cancer were created by the selection procedure.

  12. Lunar nodal tide and distance to the Moon during the Precambrian.

    PubMed

    Walker, J C; Zahnle, K J

    1986-04-17

    The pace of tidal evolution for the past approximately 450 Myr implies an Earth/Moon collision some 1,500-2,000 Myr BP, an event for which there is no corroborating evidence. Here we present the first direct determination of the lunar distance in the Precambrian. We interpret a 23.3 +/- 0.3-yr periodicity preserved in a 2,500 Myr BP Australian banded iron formation (BIF) as reflecting the climatic influence of the lunar nodal tide, which has been detected with its modern 18.6-yr periodicity in some modern climate records. The lunar distance at 2,500 Myr BP would then have been about 52 Earth radii. The implied history of Precambrian tidal friction is in accord with both the more recent palaeontological evidence and the long-term stability of the lunar orbit. The length of the Milankovitch cycles that modulate the ice ages today also evolve with the Earth-Moon system. Their detection in the Precambrian sedimentary record would then permit an independent determination of the lunar distance.

  13. In vitro propagation of olive (Olea europaea L.) by nodal segmentation of elongated shoots.

    PubMed

    Lambardi, Maurizio; Ozudogru, Elif Aylin; Roncasaglia, Romano

    2013-01-01

    Olive (Olea europaea L.), long-living, ever-green fruit tree of the Old World, has been part of a traditional landscape in the Mediterranean area for centuries. Both the fruits consumed after processing and the oil extracted from the fruits are among the main components of the Mediterranean diet, widely used for salads and cooking, as well as for preserving other food. Documentations show that the ancient use of this beautiful tree also includes lamp fuel production, wool treatment, soap production, medicine, and cosmetics. However, unlike the majority of the fruit species, olive propagation is still a laborious practice. As regards traditional propagation, rooting of cuttings and grafting stem segments onto rootstocks are possible, former being achieved only when the cuttings are collected in specific periods (spring or beginning of autumn), and latter only when skilled grafters are available. In both the cases, performance of the cultivars varies considerably. The regeneration of whole plants from ovules, on the other hand, is used only occasionally. Micropropagation of olive is not easy mainly due to explant oxidation, difficulties in explant disinfection, and labor-oriented establishment of in vitro shoot cultures. However today, the progress in micropropagation technology has made available the complete protocols for several Mediterranean cultivars. This chapter describes a micropropagation protocol based on the segmentation of nodal segments obtained from elongated shoots.

  14. Uncompacted Myelin Lamellae and Nodal Ion Channel Disruption in POEMS Syndrome.

    PubMed

    Hashimoto, Rina; Koike, Haruki; Takahashi, Mie; Ohyama, Ken; Kawagashira, Yuichi; Iijima, Masahiro; Sobue, Gen

    2015-12-01

    To elucidate the significance of uncompacted myelin lamellae (UML) and ion channel disruption at the nodes of Ranvier in the polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome, we evaluated sural nerve biopsy specimens from 33 patients with POEMS syndrome and from 7 control patients. Uncompacted myelin lamellae distribution was assessed by electron microscopy and immunofluorescence microscopy. In the POEMS patient biopsies, UML were seen more frequently in small versus large myelinated fibers. Paranodes and Schmidt-Lanterman incisures, where normal physiologic UM is located, were frequently associated with UM. Widening of the nodes of Ranvier (i.e. segmental demyelination) was not associated with UML. There was axonal hollowing with neurofilament condensation at Schmidt-Lanterman incisures with abnormal UML, suggesting axonal damage at those sites in the POEMS patient biopsies. Myelin sheath irregularity was conspicuous in large myelinated fibers and was associated with abnormally widened bizarrely shaped Schmidt-Lanterman incisures. Indirect immunofluorescent studies revealed abnormalities of sodium (pan sodium) and potassium (KCNQ2) channels, even at nonwidened nodes of Ranvier. Thus, UML was not apparently associated with segmental demyelination but seemed to be associated with axonal damage. These observations suggest that nodal ion channel disruption may be associated with functional deficits in POEMS syndrome patient nerves.

  15. Contact dynamics of elasto-plastic thin beams simulated via absolute nodal coordinate formulation

    NASA Astrophysics Data System (ADS)

    Wang, Qing-Tao; Tian, Qiang; Hu, Hai-Yan

    2016-06-01

    Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation (ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation. A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact dynamics simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system dynamics.

  16. Uncompacted Myelin Lamellae and Nodal Ion Channel Disruption in POEMS Syndrome.

    PubMed

    Hashimoto, Rina; Koike, Haruki; Takahashi, Mie; Ohyama, Ken; Kawagashira, Yuichi; Iijima, Masahiro; Sobue, Gen

    2015-12-01

    To elucidate the significance of uncompacted myelin lamellae (UML) and ion channel disruption at the nodes of Ranvier in the polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome, we evaluated sural nerve biopsy specimens from 33 patients with POEMS syndrome and from 7 control patients. Uncompacted myelin lamellae distribution was assessed by electron microscopy and immunofluorescence microscopy. In the POEMS patient biopsies, UML were seen more frequently in small versus large myelinated fibers. Paranodes and Schmidt-Lanterman incisures, where normal physiologic UM is located, were frequently associated with UM. Widening of the nodes of Ranvier (i.e. segmental demyelination) was not associated with UML. There was axonal hollowing with neurofilament condensation at Schmidt-Lanterman incisures with abnormal UML, suggesting axonal damage at those sites in the POEMS patient biopsies. Myelin sheath irregularity was conspicuous in large myelinated fibers and was associated with abnormally widened bizarrely shaped Schmidt-Lanterman incisures. Indirect immunofluorescent studies revealed abnormalities of sodium (pan sodium) and potassium (KCNQ2) channels, even at nonwidened nodes of Ranvier. Thus, UML was not apparently associated with segmental demyelination but seemed to be associated with axonal damage. These observations suggest that nodal ion channel disruption may be associated with functional deficits in POEMS syndrome patient nerves. PMID:26574667

  17. Nodal Status Assessment in Breast Cancer: Strategies of Clinical Grounds and Quality of Life Implications

    PubMed Central

    Vanni, Gianluca; Granai, Alessandra Vittoria; Petrella, Giuseppe; Buonomo, Oreste Claudio

    2014-01-01

    Even in the era of gene-expression profiling, the nodal status still remains the primary prognostic discriminant in breast cancer patients. The exclusion of node involvement using noninvasive methods could reduce the rate of axillary surgery, thereby preventing from suffering complications. However, lymphatic mapping with sentinel node biopsy (SNB) is one of the most interesting recent developments in surgical oncology. Optimization of procedure could be implemented by dual mapping injection site skills, resection of all hot or blue nodes through tracer combination, and improvement in atypical drainage patterns mapping. This anatomical analysis suggests safety measures in patients with high probability of node metastasis through a renewed interest in surgical management. The perspective of a guided axillary sampling (GAS) could represent a potential development of recent anatomical and functional acquisitions, offering a dynamic technique shared according to clinical and anatomical disease parameters. Furthermore, the surgical staging procedures may adopt a conservative approach through the evaluation of upper arm lymphatics, thus defining a functional model aimed at the reduction of short- and long-term adverse events. Quality results in breast cancer surgery need to generate oncological safety devoid of complications through renewed clinical experience. PMID:24672730

  18. Nodal energy weighted transformation: A mistuning projection and its application to FLADE™ turbines

    NASA Astrophysics Data System (ADS)

    Fitzner, Colin; Epureanu, Bogdan I.; Filippi, Sergio

    2014-01-01

    In recent years, several researchers have developed reduced-order models (ROMs) to efficiently and accurately calculate the forced response of blisks with known small mistuning. Small mistuning consists of the small blade-to-blade structural differences which destroy the inherent cyclic symmetry of the structure. This paper presents a nodal energy weighted transformation (NEWT) which can be used to construct ROMs of mistuned blisks and dual flow path systems, such as FLADE™ turbines. The NEWT approach can be interpreted as a hybrid of two existing techniques: component mode mistuning (CMM) and the subset of nominal modes (SNM). Similar to the previous methods, NEWT assumes that the mistuned modes of the system are a linear combination of tuned modes. However, NEWT differs from its predecessors in the blisk substructuring and in the mistuning projection. Numerical results obtained using full order models, CMM, and NEWT are presented and compared over multiple frequency ranges for a finite element model of a blisk and that of a FLADE™ turbine. These results show that ROMs based on NEWT have several attractive features: (a) the accuracy of the ROMs is comparable to ROMs based on CMM, and can be improved by increasing the size of the projection mode subset; (b) no necessary modifications are needed to analyze FLADE™ turbines; and (c) the response of all modes can be predicted well even if they are not blade dominated.

  19. Analysis of the influence of elective nodal irradiation on postirradiation pulmonary function

    SciTech Connect

    Curran, W.J. Jr.; Moldofsky, P.J.; Solin, L.J. )

    1990-06-01

    Irradiation (RT) field selection for bronchogenic carcinoma is based on such factors as extent of disease, pulmonary function, and the perceived need for elective nodal irradiation (ENI). A technique of superimposing a patient's RT treatment film onto his quantitative perfusion lung scan can predict the fractional volume of perfused lung receiving RT and has been shown to reliably estimate the minimum post-RT pulmonary function as measured by the forced expiratory volume in one second (FEV1). This technique has been applied to 20 patients with nonresected clinically staged T1-4N0M0 lesions to quantify the pulmonary impact of varying degrees of ENI. The five treatment volumes selected were as follows: (1) tumor volume plus a 2-cm margin; (2) volume 1 plus ipsilateral hilum; (3) volume 2 plus mediastinum; (4) volume 3 plus supraclavicular fossae; and (5) volume 4 plus contralateral hilum. The median pre-RT FEV1 was 2.0 l, and the median predicted minimal post-RT FEV1 for each proposed field was field 1, 1.7 l; field 2, 1.5 l; field 3, 1.3 l; field 4, 1.1.; and field 5, 1.0 l. The decline in median predicted FEV1 with each increase in field size ranged from 2% to 12%, with a broad range of declines for each field. Such quantification can aid in decisions regarding ENI for patients with impaired pulmonary function.

  20. Loss of nodal quasiparticle integrity in underdoped YBa2Cu3O6+x

    NASA Astrophysics Data System (ADS)

    Fournier, D.; Levy, G.; Pennec, Y.; McChesney, J. L.; Bostwick, A.; Rotenberg, E.; Liang, R.; Hardy, W. N.; Bonn, D. A.; Elfimov, I. S.; Damascelli, A.

    2010-11-01

    A central question in the study of high-temperature superconductivity is whether this phenomenon is linked to the doped antiferromagnetic Mott insulator or whether it emerges from a Fermi-liquid state across the whole cuprate phase diagram. Discriminating between these orthogonal cases hinges on the quantitative determination of the elusive quasiparticle strength Z as a function of hole-doping p, from the heavily overdoped to the deeply underdoped regime. Here we show, by means of angle-resolved photoemission spectroscopy and an in situ doping technique, that the electronic structure of the overdoped metal (0.24<=p<=0.37) is in remarkable agreement with density functional theory and Fermi-liquid-like descriptions. However, below p~0.10-0.15, we observe the loss of nodal quasiparticle integrity. This marks a clear departure from Fermi-liquid behaviour and a more rapid than expected crossover to Mott physics, indicating that the physical properties of underdoped cuprates are dominated by incoherent excitations.

  1. Alignment of a three-mirror anastigmatic telescope using nodal aberration theory.

    PubMed

    Gu, Zhiyuan; Yan, Changxiang; Wang, Yang

    2015-09-21

    Most computer-aided alignment methods for optical systems are based on numerical algorithms at present, which omit aberration theory. This paper presents a novel alignment algorithm for three-mirror anastigmatic (TMA) telescopes using Nodal Aberration Theory (NAT). The aberration field decenter vectors and boresight error of misaligned TMA telescopes are derived. Two alignment models based on 3rd and 5th order NAT are established successively and compared in the same alignment example. It is found that the average and the maximum RMS wavefront errors in the whole field of view of 0.3° × 0.15° are 0.063 λ (λ = 1 μm) and 0.068 λ respectively after the 4th alignment action with the 3rd order model, and 0.011 λ and 0.025 λ (nominal values) respectively after the 3rd alignment action with the 5th order model. Monte-Carlo alignment simulations are carried out with the 5th order model. It shows that the 5th order model still has good performance even when the misalignment variables are large (-1 mm≤linear misalignment≤1 mm, -0.1°≤angular misalignment≤0.1°), and multiple iterative alignments are needed when the misalignment variables increase. PMID:26406716

  2. In vitro regeneration in olive (Olea europaea L.) cv, 'Frontio' from nodal segments.

    PubMed

    Mangal, Manisha; Sharma, Dheeraj; Sharma, Mamta; Kumar, Sunil

    2014-09-01

    An efficient and reproducible protocol for plantlet regeneration from nodal segments of Olive cv 'Frontio' has been developed. Media and explants browning due to exudation of phenolics from the explants were controlled by fortification of the medium with 100 mg/L ascorbic acid. Best establishment of olive explants was observed on half-strength MS salts fortified with 2.0 mg/L 6-benzylaminopurine (BAP), which resulted in 56.2% of bud break and 93.7% survival whereas, a combination of full strength MS medium with 1.0 mg/L each of 3-indole-butyric-acid (IBA) and kinetin was found to be the best for shoot multiplication, in terms of number of shoots (3.6 shoots/explant) and shoot length (2.2 cm). The in vitro shoots were rooted on half-strength MS medium fortified with 0.2 mg/L IBA and 0.2 mg/L alpha-naphthalene acetic acid (NAA) with 1.5 g/L activated charcoal, which supported optimum rooting (60%), with an average of 2-3 roots/shoot, about 2.4 cm length were produced on four weeks of culture.

  3. Pax3 functions at a nodal point in melanocyte stem cell differentiation.

    PubMed

    Lang, Deborah; Lu, Min Min; Huang, Li; Engleka, Kurt A; Zhang, Maozhen; Chu, Emily Y; Lipner, Shari; Skoultchi, Arthur; Millar, Sarah E; Epstein, Jonathan A

    2005-02-24

    Most stem cells are not totipotent. Instead, they are partially committed but remain undifferentiated. Upon appropriate stimulation they are capable of regenerating mature cell types. Little is known about the genetic programmes that maintain the undifferentiated phenotype of lineage-restricted stem cells. Here we describe the molecular details of a nodal point in adult melanocyte stem cell differentiation in which Pax3 simultaneously functions to initiate a melanogenic cascade while acting downstream to prevent terminal differentiation. Pax3 activates expression of Mitf, a transcription factor critical for melanogenesis, while at the same time it competes with Mitf for occupancy of an enhancer required for expression of dopachrome tautomerase, an enzyme that functions in melanin synthesis. Pax3-expressing melanoblasts are thus committed but undifferentiated until Pax3-mediated repression is relieved by activated beta-catenin. Thus, a stem cell transcription factor can both determine cell fate and simultaneously maintain an undifferentiated state, leaving a cell poised to differentiate in response to external stimuli. PMID:15729346

  4. Directed nanoscale self-assembly of molecular wires interconnecting nodal points using Monte Carlo simulations

    SciTech Connect

    Boscoboinik, A. M.; Manzi, S. J.; Tysoe, W. T.; Pereyra, V. D.; Boscoboinik, J. A.

    2015-09-10

    The influence of directing agents in the self-assembly of molecular wires to produce two-dimensional electronic nanoarchitectures is studied here using a Monte Carlo approach to simulate the effect of arbitrarily locating nodal points on a surface, from which the growth of self-assembled molecular wires can be nucleated. This is compared to experimental results reported for the self-assembly of molecular wires when 1,4-phenylenediisocyanide (PDI) is adsorbed on Au(111). The latter results in the formation of (Au-PDI)n organometallic chains, which were shown to be conductive when linked between gold nanoparticles on an insulating substrate. The present study analyzes, by means of stochastic methods, the influence of variables that affect the growth and design of self-assembled conductive nanoarchitectures, such as the distance between nodes, coverage of the monomeric units that leads to the formation of the desired architectures, and the interaction between the monomeric units. As a result, this study proposes an approach and sets the stage for the production of complex 2D nanoarchitectures using a bottom-up strategy but including the use of current state-of-the-art top-down technology as an integral part of the self-assembly strategy.

  5. Directed nanoscale self-assembly of molecular wires interconnecting nodal points using Monte Carlo simulations

    DOE PAGES

    Boscoboinik, A. M.; Manzi, S. J.; Tysoe, W. T.; Pereyra, V. D.; Boscoboinik, J. A.

    2015-09-10

    The influence of directing agents in the self-assembly of molecular wires to produce two-dimensional electronic nanoarchitectures is studied here using a Monte Carlo approach to simulate the effect of arbitrarily locating nodal points on a surface, from which the growth of self-assembled molecular wires can be nucleated. This is compared to experimental results reported for the self-assembly of molecular wires when 1,4-phenylenediisocyanide (PDI) is adsorbed on Au(111). The latter results in the formation of (Au-PDI)n organometallic chains, which were shown to be conductive when linked between gold nanoparticles on an insulating substrate. The present study analyzes, by means of stochasticmore » methods, the influence of variables that affect the growth and design of self-assembled conductive nanoarchitectures, such as the distance between nodes, coverage of the monomeric units that leads to the formation of the desired architectures, and the interaction between the monomeric units. As a result, this study proposes an approach and sets the stage for the production of complex 2D nanoarchitectures using a bottom-up strategy but including the use of current state-of-the-art top-down technology as an integral part of the self-assembly strategy.« less

  6. Convergence properties of iterative algorithms for solving the nodal diffusion equations

    SciTech Connect

    Azmy, Y Y; Kirk, B L

    1990-01-01

    We drive the five point form of the nodal diffusion equations in two-dimensional Cartesian geometry and develop three iterative schemes to solve the discrete-variable equations: the unaccelerated, partial Successive Over Relaxation (SOR), and the full SOR methods. By decomposing the iteration error into its Fourier modes, we determine the spectral radius of each method for infinite medium, uniform model problems, and for the unaccelerated and partial SOR methods for finite medium, uniform model problems. Also for the two variants of the SOR method we determine the optimal relaxation factor that results in the smallest number of iterations required for convergence. Our results indicate that the number of iterations for the unaccelerated and partial SOR methods is second order in the number of nodes per dimension, while, for the full SOR this behavior is first order, resulting in much faster convergence for very large problems. We successfully verify the results of the spectral analysis against those of numerical experiments, and we show that for the full SOR method the linear dependence of the number of iterations on the number of nodes per dimension is relatively insensitive to the value of the relaxation parameter, and that it remains linear even for heterogenous problems. 14 refs., 1 fig.

  7. Anisotropic softening of magnetic excitations along the nodal direction in superconducting cuprates

    NASA Astrophysics Data System (ADS)

    Guarise, M.; Piazza, B. Dalla; Berger, H.; Giannini, E.; Schmitt, T.; Rønnow, H. M.; Sawatzky, G. A.; van den Brink, J.; Altenfeld, D.; Eremin, I.; Grioni, M.

    2014-12-01

    The high-Tc cuprate superconductors are close to antiferromagnetic order. Recent measurements of magnetic excitations have reported an intriguing similarity to the spin waves—magnons—of the antiferromagnetic insulating parent compounds, suggesting that magnons may survive in damped, broadened form throughout the phase diagram. Here we show by resonant inelastic X-ray scattering on Bi2Sr2CaCu2O8+δ (Bi-2212) that the analogy with spin waves is only partial. The magnon-like features collapse along the nodal direction in momentum space and exhibit a photon energy dependence markedly different from the Mott-insulating case. These observations can be naturally described by the continuum of charge and spin excitations of correlated electrons. The persistence of damped magnons could favour scenarios for superconductivity built from quasiparticles coupled to spin fluctuations. However, excitation spectra composed of particle-hole excitations suggest that superconductivity emerges from a coherent treatment of electronic spin and charge in the form of quasiparticles with very strong magnetic correlations.

  8. Nodal Follicular Lymphomas: A Clinicopathological Study from a Tertiary Care Centre in South India.

    PubMed

    Supari, Divya; Ananthamurthy, Anuradha

    2016-06-01

    The aim of this study was to assess the distribution of nodal follicular lymphomas (FL) among various subtypes of non- Hodgkin lymphoma and to study their clinico-pathological features. Clinical details, histomorphology including grading & patterns and immunoprofile of 44 cases were studied. Majority of the cases were grade 1 (61 %) FL. BCL2 positivity was higher in low grade FLs (97 %). An associated diffuse large B cell lymphoma component was seen in 18 % and was present only in conjunction with grade 3 FL. Majority of our patients (76 %) had a high FLIPI score and belonged to the high risk group. Our study showed that the incidence of FLs is much lower in the Indian population (14.5 %) when compared to western studies and majority were of low grade. Although there was complete initial response to treatment, relapse was common and was much higher in low grade FLs with diffuse areas on histology, Ann Arbor stage III/IV and FLIPI scores of 3-5. PMID:27065580

  9. Tuberculous Lymphadenitis Mimicking Nodal Metastasis in Follicular Variant Papillary Thyroid Carcinoma

    PubMed Central

    Atun, Jenny Maureen

    2016-01-01

    Tuberculous (TB) lymphadenitis can mimic cervical node metastasis from papillary thyroid carcinoma (PTC) since the distribution and appearance of affected lymph nodes are similar. We present the case of an asymptomatic 50-year-old Filipino who sought consult for a gradually enlarging anterior neck mass and a single palpable cervical lymph node. Preoperative workup suggested a thyroid malignancy with nodal metastasis. He underwent total thyroidectomy with node dissection where histopathology confirmed follicular variant- (FV-) PTC. Lymph node examination, however, revealed TB lymphadenitis, and the patient was given standard antimycobacterial therapy. This is the first documented case in Southeast Asia, a high TB burden region. This is also the first report involving FV-PTC, which has features between those of conventional PTC and follicular thyroid carcinoma. The case suggests that, in endemic areas, TB should be a differential in the etiology of cervical lymphadenopathy in PTC patients. In developed countries, this differential diagnosis is also valuable because of the increasing incidence of HIV and TB coinfection. Proper preoperative evaluation is important and needs to be highlighted in the formulation of local guidelines. PMID:27746818

  10. Light Spectral Quality Effects on the Growth of Potato (Solanum Tuberosum L.) Nodal Cuttings in Vitro

    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 cuttings of potato (Solanum tuberosum L.) 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 lamps (LPS/CWF). For cultivars, stem lengths after 4 wks were longest under LPS, follow by RF, LPS/CWF, VF, and BF (in descending order). Microscopic studies revealed that cells were shortest when cultured in BF or VF environments, and were longest in RF or LPS lamp environments. The highest number axillary branches occurred on plantlets grown with LPS or LPS/CWF, whereas the lowest number occurred with BF. No leaf or stem edema (callus or gall-like growths) occurred iwth LPS or LPS/cwf lighting, and no edema occurred on cv. Norland plantlets, regardless of lighting. Results suggest that shoot morphologic development of in vitro grown potato plants can be controlled by controlling irradiant spectral quality.

  11. Nodality effects during equivalence class formation: An extension to sight-word reading and concept development.

    PubMed

    Kennedy, C H; Itkonen, T; Lindquist, K

    1994-01-01

    Three students with moderate disabilities were taught to read and match-to-sample sight words comprising stimulus sets based upon the four food groups. We taught students conditional discriminations within four four-member sets using a single-sample/four-comparison procedure. Students were taught A-B, B-C, and C-D conditional discriminations for each of the four potential stimulus classes. Subsequent probes tested for relations based upon symmetry and one-node and two-node transitivity. The performances for all students indicated that symmetric relations emerged before one-node transitive relations, and that one-node transitive relations emerged before two-node transitive relations. These results are consistent with a pattern of responding, referred to as a "nodality effect," in which relations with fewer nodes are demonstrated prior to the demonstration of relations with a greater number of nodes. These results extend this area of research to sight-word reading for students with moderate disabilities. PMID:16795844

  12. Nodality effects during equivalence class formation: An extension to sight-word reading and concept development

    PubMed Central

    Kennedy, Craig H.; Itkonen, Tiina; Lindquist, Kristin

    1994-01-01

    Three students with moderate disabilities were taught to read and match-to-sample sight words comprising stimulus sets based upon the four food groups. We taught students conditional discriminations within four four-member sets using a single-sample/four-comparison procedure. Students were taught A-B, B-C, and C-D conditional discriminations for each of the four potential stimulus classes. Subsequent probes tested for relations based upon symmetry and one-node and two-node transitivity. The performances for all students indicated that symmetric relations emerged before one-node transitive relations, and that one-node transitive relations emerged before two-node transitive relations. These results are consistent with a pattern of responding, referred to as a “nodality effect,” in which relations with fewer nodes are demonstrated prior to the demonstration of relations with a greater number of nodes. These results extend this area of research to sight-word reading for students with moderate disabilities. PMID:16795844

  13. Alignment of a three-mirror anastigmatic telescope using nodal aberration theory.

    PubMed

    Gu, Zhiyuan; Yan, Changxiang; Wang, Yang

    2015-09-21

    Most computer-aided alignment methods for optical systems are based on numerical algorithms at present, which omit aberration theory. This paper presents a novel alignment algorithm for three-mirror anastigmatic (TMA) telescopes using Nodal Aberration Theory (NAT). The aberration field decenter vectors and boresight error of misaligned TMA telescopes are derived. Two alignment models based on 3rd and 5th order NAT are established successively and compared in the same alignment example. It is found that the average and the maximum RMS wavefront errors in the whole field of view of 0.3° × 0.15° are 0.063 λ (λ = 1 μm) and 0.068 λ respectively after the 4th alignment action with the 3rd order model, and 0.011 λ and 0.025 λ (nominal values) respectively after the 3rd alignment action with the 5th order model. Monte-Carlo alignment simulations are carried out with the 5th order model. It shows that the 5th order model still has good performance even when the misalignment variables are large (-1 mm≤linear misalignment≤1 mm, -0.1°≤angular misalignment≤0.1°), and multiple iterative alignments are needed when the misalignment variables increase.

  14. Odd-parity superconductors with two-component order parameters: nematic and chiral, gapped and nodal

    NASA Astrophysics Data System (ADS)

    Venderbos, Jörn W. F.; Kozii, Vladyslav; Fu, Liang

    Motivated by growing experimental evidence that superconductivity in the doped topological insulator CuxBi2Se3 has an odd-parity pairing with broken rotational symmetry, we study the general class of odd-parity superconductors with two-component order parameters. We address the energetics and physical properties of different superconducting phases, with special emphasis on the role of spin-orbit coupling, which is generally strong in topological insulator and related materials. We show that within the weak-coupling BCS theory, in the absence of spin-orbit coupling, isotropic superconductors are favored, which are analogs of the A- or B-phase of 3He. In the presence of spin-orbit coupling, however, we find that a nematic superconducting phase, which spontaneously breaks rotational symmetry are favored. We determine the superconducting gap structures and find, in addition to fully gapped odd-parity superconductors, nodal superconductors with Dirac and Weyl quasiparticles, which are markedly different from superfluid phases of 3He.

  15. Genetic analysis of the roles of Hh, FGF8, and nodal signaling during catecholaminergic system development in the zebrafish brain.

    PubMed

    Holzschuh, Jochen; Hauptmann, Giselbert; Driever, Wolfgang

    2003-07-01

    CNS catecholaminergic neurons can be distinguished by their neurotransmitters as dopaminergic or noradrenergic and form in distinct regions at characteristic embryonic stages. This raises the question of whether all catecholaminergic neurons of one transmitter type are specified by the same set of factors. Therefore, we performed genetic analyses to define signaling requirements for the specification of distinct clusters of catecholaminergic neurons in zebrafish. In mutants affecting midbrain- hindbrain boundary (MHB) organizer formation, the earliest ventral diencephalic dopaminergic neurons appear normal. However, after 2 d of development, we observed fewer cells than in wild types, which suggests that the MHB provides proliferation or survival factors rather than specifying ventral diencephalic dopaminergic clusters. In hedgehog (Hh) pathway mutants, the formation of catecholaminergic neurons is affected only in the pretectal cluster. Surprisingly, neither fibroblast growth factor 8 (FGF8) alone nor in combination with Hh signaling is required for specification of early developing dopaminergic neurons. We analyzed the formation of prosomeric territories in the forebrain of Hh and Nodal pathway mutants to determine whether the absence of specific dopaminergic clusters may be caused by early patterning defects ablating corresponding parts of the CNS. In Nodal pathway mutants, ventral diencephalic and pretectal catecholaminergic neurons fail to develop, whereas both anatomical structures form at least in part. This suggests that Nodal signaling is required for catecholaminergic neuron specification. In summary, our results do not support the previously suggested dominant roles for sonic hedgehog and Fgf8 in specification of the first catecholaminergic neurons, but instead indicate a novel role for Nodal signaling in this process. PMID:12843251

  16. Intensity-Modulated Radiation Therapy for the Treatment of Squamous Cell Anal Cancer With Para-aortic Nodal Involvement

    SciTech Connect

    Hodges, Joseph C.; Das, Prajnan; Eng, Cathy; Reish, Andrew G.; Beddar, A. Sam; Delclos, Marc E.; Krishnan, Sunil; Crane, Christopher H.

    2009-11-01

    Purpose: To determine the rates of toxicity, locoregional control, distant control, and survival in anal cancer patients with para-aortic nodal involvement, treated with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy at a single institution. Methods and Materials: Between 2001 and 2007, 6 patients with squamous cell anal cancer and para-aortic nodal involvement were treated with IMRT and concurrent infusional 5-fluorouracil and cisplatin. The primary tumor was treated with a median dose of 57.5 Gy (range, 54-60 Gy), involved para-aortic, pelvic, and inguinal lymph nodes were treated with a median dose of 55 Gy (range, 50.5-55 Gy), and noninvolved nodal regions were treated with a median dose of 45 Gy (range, 43.5-45 Gy). Results: After a median follow-up of 25 months, none of the patients had a recurrence at the primary tumor, pelvic/inguinal nodes, or para-aortic nodes, whereas 2 patients developed distant metastases to the liver. Four of the 6 patients are alive. The 3-year actuarial locoregional control, distant control, and overall survival rates were 100%, 56%, and 63%, respectively. Four of the 6 patients developed Grade 3 acute gastrointestinal toxicity during chemoradiation. Conclusions: Intensity-modulated radiotherapy and concurrent chemotherapy could potentially serve as definitive therapy in anal cancer patients with para-aortic nodal involvement. Adjuvant chemotherapy may be indicated in these patients, as demonstrated by the distant failure rates. These patients need to be followed carefully because of the potential for treatment-related toxicities.

  17. An efficient in vitro regeneration protocol for a natural dye yielding plant, Strobilanthes flaccidifolious Nees., from nodal explants.

    PubMed

    Deb, Chitta Ranjan; Arenmongla, T

    2012-11-01

    Adventitious shoot buds formation from axillary buds of nodal segments of S. flaccidifolious was achieved on MS medium containing sucrose (3%, w/v), and a-naphthalene acetic acid (NAA; 3 microM) and benzyl adenine (3 microM) in combination. The nodal segments were primed on 'Growtak Sieve' for 48 h on MS medium containing sucrose (2%), polyvinyl pyrollidone (200 mgL(-1)) as antioxidant. About 80% of primed nodal segments responded positively and formed approximately 12 adventitious shoot buds per explants from explants collected during October-November months of every year. The shoot buds converted into plantlets on MS medium containing sucrose (3%) and kinetin (3 microM) where approximately 7 micro shoots developed per subculture after 8 weeks of culture. The regenerated micro shoots induced average 14 roots/plant on medium containing NAA (3 microM). The regenerates were hardened for 6-7 weeks on medium with 1/2MS salt solution and sucrose (2%) under normal laboratory condition before transferring to potting mix. About 70% transplants survived after two months of transfer. PMID:23305032

  18. Negative predictive value of preoperative computed tomography in determining pathologic local invasion, nodal disease, and abdominal metastases in gastric cancer

    PubMed Central

    Kagedan, D.J.; Frankul, F.; El-Sedfy, A.; McGregor, C.; Elmi, M.; Zagorski, B.; Dixon, M.E.; Mahar, A.L.; Vasilevska-Ristovska, J.; Helyer, L.; Rowsell, C.; Swallow, C.J.; Law, C.H.; Coburn, N.G.

    2016-01-01

    Background Before undergoing curative-intent resection of gastric adenocarcinoma (ga), most patients undergo abdominal computed tomography (ct) imaging to determine contraindications to resection (local invasion, distant metastases). However, the ability to detect contraindications is variable, and the literature is limited to single-institution studies. We sought to assess, on a population level, the clinical relevance of preoperative ct in evaluating the resectability of ga tumours in patients undergoing surgery. Methods In a provincial cancer registry, 2414 patients with ga diagnosed during 2005–2008 at 116 institutions were identified, and a primary chart review of radiology, operative, and pathology reports was performed for all patients. Preoperative abdominal ct reports were compared with intraoperative findings and final pathology reports (reference standard) to determine the negative predictive value (npv) of ct in assessing local invasion, nodal involvement, and intra-abdominal metastases. Results Among patients undergoing gastrectomy, the npv of ct imaging in detecting local invasion was 86.9% (n = 536). For nodal metastasis, the npv of ct was 43.3% (n = 450). Among patients undergoing surgical exploration, the npv of ct for intra-abdominal metastases was 52.3% (n = 407). Conclusions Preoperative abdominal ct imaging reported as negative is most accurate in determining local invasion and least accurate in nodal assessment. The poor npv of ct should be taken into account when selecting patients for staging laparoscopy. PMID:27536178

  19. Software Certification - Coding, Code, and Coders

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  20. Positron Emission Tomography for Neck Evaluation Following Definitive Treatment with Chemoradiotherapy for Locoregionally Advanced Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Bar-Ad, Voichita; Mishra, Mark; Ohri, Nitin; Intenzo, Charles

    2013-01-01

    Objectives The objective of the current review was to assess published data on the role of Positron Emission Tomography (PET) for evaluation of nodal residual disease after definitive chemoradiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods Studies were identified by searching PubMed electronic databases. Only studies using a post-chemoradiotherapy PET for nodal residual disease evaluation were included in the present review. Both prospective and retrospective studies were included. Information regarding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET for detecting nodal residual disease after definitive chemoradiotherapy for HNSCC was extracted and analyzed. Results Twenty published studies were included in the present review. Existing data suggest that a negative post-chemoradiotherapy PET scan is associated with a negative predictive value up to 100%. The sensitivity of PET in detecting nodal residual disease is greater for scans performed ≥ 10 weeks after definitive treatment with chemoradiotherapy for HNSCC. Conclusions Further studies are needed to quantify the reliability of PET in detecting nodal residual disease after chemoradiotherapy for locoregionally advanced HNSCC. The optimal timing of PET imaging after chemoradiotherapy remains to be defined. PMID:21864252