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Sample records for all-electron mixed-basis approach

  1. Ab initio GW quasiparticle energies of small sodium clusters by an all-electron mixed-basis approach

    NASA Astrophysics Data System (ADS)

    Ishii, Soh; Ohno, Kaoru; Kawazoe, Yoshiyuki; Louie, Steven G.

    2001-04-01

    A state-of-the-art GW calculation is carried out for small sodium clusters, Na2, Na4, Na6, and Na8. The quasiparticle energies are evaluated by employing an ab initio GW code based on an all-electron mixed-basis approach, which uses both plane waves and atomic orbitals as basis functions. The calculated ionization potential and the electron affinity are in excellent agreement with available experimental data. The exchange and correlation parts to the electron self-energy within the GW approximation are presented from the viewpoint of their size dependence. In addition, the effect of the off-diagonal elements of the self-energy corrections to the local-density-approximation exchange-correlation potential is discussed. Na2 and Na8 have a larger energy gap than Na4 and Na6, consistent with the fact that they are magic number clusters.

  2. All electronic approach for high-throughput cell trapping and lysis with electrical impedance monitoring.

    PubMed

    Ameri, Shideh Kabiri; Singh, Pramod K; Dokmeci, Mehmet R; Khademhosseini, Ali; Xu, Qiaobing; Sonkusale, Sameer R

    2014-04-15

    We present a portable lab-on-chip device for high-throughput trapping and lysis of single cells with in-situ impedance monitoring in an all-electronic approach. The lab-on-chip device consists of microwell arrays between transparent conducting electrodes within a microfluidic channel to deliver and extract cells using alternating current (AC) dielectrophoresis. Cells are lysed with high efficiency using direct current (DC) electric fields between the electrodes. Results are presented for trapping and lysis of human red blood cells. Impedance spectroscopy is used to estimate the percentage of filled wells with cells and to monitor lysis. The results show impedance between electrodes decreases with increase in the percentage of filled wells with cells and drops to a minimum after lysis. Impedance monitoring provides a reasonably accurate measurement of cell trapping and lysis. Utilizing an all-electronic approach eliminates the need for bulky optical components and cameras for monitoring.

  3. Spectrum-splitting approach for Fermi-operator expansion in all-electron Kohn-Sham DFT calculations

    NASA Astrophysics Data System (ADS)

    Motamarri, Phani; Gavini, Vikram; Bhattacharya, Kaushik; Ortiz, Michael

    2017-01-01

    We present a spectrum-splitting approach to conduct all-electron Kohn-Sham density functional theory (DFT) calculations by employing Fermi-operator expansion of the Kohn-Sham Hamiltonian. The proposed approach splits the subspace containing the occupied eigenspace into a core subspace, spanned by the core eigenfunctions, and its complement, the valence subspace, and thereby enables an efficient computation of the Fermi-operator expansion by reducing the expansion to the valence-subspace projected Kohn-Sham Hamiltonian. The key ideas used in our approach are as follows: (i) employ Chebyshev filtering to compute a subspace containing the occupied states followed by a localization procedure to generate nonorthogonal localized functions spanning the Chebyshev-filtered subspace; (ii) compute the Kohn-Sham Hamiltonian projected onto the valence subspace; (iii) employ Fermi-operator expansion in terms of the valence-subspace projected Hamiltonian to compute the density matrix, electron density, and band energy. We demonstrate the accuracy and performance of the method on benchmark materials systems involving silicon nanoclusters up to 1330 electrons, a single gold atom, and a six-atom gold nanocluster. The benchmark studies on silicon nanoclusters revealed a staggering fivefold reduction in the Fermi-operator expansion polynomial degree by using the spectrum-splitting approach for accuracies in the ground-state energies of ˜10-4Ha/atom with respect to reference calculations. Further, numerical investigations on gold suggest that spectrum splitting is indispensable to achieve meaningful accuracies, while employing Fermi-operator expansion.

  4. A divide and conquer real-space approach for all-electron molecular electrostatic potentials and interaction energies

    NASA Astrophysics Data System (ADS)

    Losilla, S. A.; Sundholm, D.

    2012-06-01

    A computational scheme to perform accurate numerical calculations of electrostatic potentials and interaction energies for molecular systems has been developed and implemented. Molecular electron and energy densities are divided into overlapping atom-centered atomic contributions and a three-dimensional molecular remainder. The steep nuclear cusps are included in the atom-centered functions making the three-dimensional remainder smooth enough to be accurately represented with a tractable amount of grid points. The one-dimensional radial functions of the atom-centered contributions as well as the three-dimensional remainder are expanded using finite element functions. The electrostatic potential is calculated by integrating the Coulomb potential for each separate density contribution, using our tensorial finite element method for the three-dimensional remainder. We also provide algorithms to compute accurate electron-electron and electron-nuclear interactions numerically using the proposed partitioning. The methods have been tested on all-electron densities of 18 reasonable large molecules containing elements up to Zn. The accuracy of the calculated Coulomb interaction energies is in the range of 10-3 to 10-6 Eh when using an equidistant grid with a step length of 0.05 a0.

  5. Accurate heat of formation for fully hydrided LaNi5 via the all-electron FLAPW approach

    NASA Astrophysics Data System (ADS)

    Zhao, Yu-Jun; Freeman, A. J.

    2003-03-01

    It is known that the theoretical/computational determination of the heat of formation for La_2Ni_10H_14, Δ H_f, is overestimated theoretically by 50% or more when a pseudopotential approach is employed.(Tatsumi et al), PRB 64, 184105(2001) Does this signify a failure of first-principles total energy calculations? Here, we employ the full-potential linearized augmented plane wave (FLAPW) method(Wimmer, Krakauer, Weinert, and Freeman, PRB 24), 864 (1981). within both the generalized gradient approximation (GGA) and the localized density approximation (LDA), with a highly precise treatment of the total energy of H2 molecule due to its critical role in the calculation of Δ H_f. The calculated Δ Hf (-31.1 KJ/mol-H_2) and geometry structure within GGA are in excellent agreement with experiment ( ˜ -32 KJ/mol-H_2). While LDA calculations underestimate the volume of LaNi5 by 10.4%, the final value of Δ Hf (-31.2 KJ/mol-H_2) is also in excellent agreement with experiment. These results show the success rather than failure of first-principles calculations. The electronic properties indicate that charge transfer from the interstitial region to the H atoms stabilizes the fully hydrided LaNi_5.

  6. A novel Gaussian-Sinc mixed basis set for electronic structure calculations

    SciTech Connect

    Jerke, Jonathan L.; Lee, Young; Tymczak, C. J.

    2015-08-14

    A Gaussian-Sinc basis set methodology is presented for the calculation of the electronic structure of atoms and molecules at the Hartree–Fock level of theory. This methodology has several advantages over previous methods. The all-electron electronic structure in a Gaussian-Sinc mixed basis spans both the “localized” and “delocalized” regions. A basis set for each region is combined to make a new basis methodology—a lattice of orthonormal sinc functions is used to represent the “delocalized” regions and the atom-centered Gaussian functions are used to represent the “localized” regions to any desired accuracy. For this mixed basis, all the Coulomb integrals are definable and can be computed in a dimensional separated methodology. Additionally, the Sinc basis is translationally invariant, which allows for the Coulomb singularity to be placed anywhere including on lattice sites. Finally, boundary conditions are always satisfied with this basis. To demonstrate the utility of this method, we calculated the ground state Hartree–Fock energies for atoms up to neon, the diatomic systems H{sub 2}, O{sub 2}, and N{sub 2}, and the multi-atom system benzene. Together, it is shown that the Gaussian-Sinc mixed basis set is a flexible and accurate method for solving the electronic structure of atomic and molecular species.

  7. All-electron first-principles GW+Bethe-Salpeter calculation for optical absorption spectra of sodium clusters

    SciTech Connect

    Noguchi, Yoshifumi; Ohno, Kaoru

    2010-04-15

    The optical absorption spectra of sodium clusters (Na{sub 2n}, n{<=} 4) are calculated by using an all-electron first-principles GW+Bethe-Salpeter method with the mixed-basis approach within the Tamm-Dancoff approximation. In these small systems, the excitonic effect strongly affects the optical properties due to the confinement of exciton in the small system size. The present state-of-the-art method treats the electron-hole two-particle Green's function by incorporating the ladder diagrams up to the infinite order and therefore takes into account the excitonic effect in a good approximation. We check the accuracy of the present method by comparing the resulting spectra with experiments. In addition, the effect of delocalization in particular in the lowest unoccupied molecular orbital in the GW quasiparticle wave function is also discussed by rediagonalizing the Dyson equation.

  8. Obtaining Mixed-Basis Ising-Like Expansions of Binary Alloys from First Principles

    NASA Astrophysics Data System (ADS)

    Hart, Gus L. W.; Sanati, Mahdi; Wang, Ligen; Zunger, Alex

    2002-03-01

    Many electronic and structural properties of A_1-xBx alloys can be predicted theoretically if one can find (and quickly compute) the ``configurational energy function''--that is, the energy for any given configuration of A and B atoms on the crystal lattice. Cluster expansion methods provide one such approach. We describe our mixed-basis cluster expansion (MBCE) based on first-principles total energy calculations for only a few ordered A_mBn compounds. Our MBCE can robustly predict a variety of material properties including ground states, phase diagrams, precipitate formation, etc. Specifically, we illustrate how systematic choice of interaction parameters, numerical parameters, and choice of input structures can significantly increase the accuracy and the predictive capability of the expansion. We illustrate how the fit of LDA data can be done essentially automatically. Examples include Cu-Au, Ni-Pt, and Sc_1-xBox_xS.

  9. Label-free all-electronic biosensing in microfluidic systems

    NASA Astrophysics Data System (ADS)

    Stanton, Michael A.

    Label-free, all-electronic detection techniques offer great promise for advancements in medical and biological analysis. Electrical sensing can be used to measure both interfacial and bulk impedance changes in conducting solutions. Electronic sensors produced using standard microfabrication processes are easily integrated into microfluidic systems. Combined with the sensitivity of radiofrequency electrical measurements, this approach offers significant advantages over competing biological sensing methods. Scalable fabrication methods also provide a means of bypassing the prohibitive costs and infrastructure associated with current technologies. We describe the design, development and use of a radiofrequency reflectometer integrated into a microfluidic system towards the specific detection of biologically relevant materials. We developed a detection protocol based on impedimetric changes caused by the binding of antibody/antigen pairs to the sensing region. Here we report the surface chemistry that forms the necessary capture mechanism. Gold-thiol binding was utilized to create an ordered alkane monolayer on the sensor surface. Exposed functional groups target the N-terminus, affixing a protein to the monolayer. The general applicability of this method lends itself to a wide variety of proteins. To demonstrate specificity, commercially available mouse anti- Streptococcus Pneumoniae monoclonal antibody was used to target the full-length recombinant pneumococcal surface protein A, type 2 strain D39 expressed by Streptococcus Pneumoniae. We demonstrate the RF response of the sensor to both the presence of the surface decoration and bound SPn cells in a 1x phosphate buffered saline solution. The combined microfluidic sensor represents a powerful platform for the analysis and detection of cells and biomolecules.

  10. All-electronic line width reduction in a semiconductor diode laser using a crystalline microresonator

    NASA Astrophysics Data System (ADS)

    Rury, Aaron S.; Mansour, Kamjou; Yu, Nan

    2015-07-01

    This study examines the capability to significantly suppress the frequency noise of a semiconductor distributed feedback diode laser using a universally applicable approach: a combination of a high-Q crystalline whispering gallery mode microresonator reference and the Pound-Drever-Hall locking scheme using an all-electronic servo loop. An out-of-loop delayed self-heterodyne measurement system demonstrates the ability of this approach to reduce a test laser's absolute line width by nearly a factor of 100. In addition, in-loop characterization of the laser stabilized using this method demonstrates a 1-kHz residual line width with reference to the resonator frequency. Based on these results, we propose that utilization of an all-electronic loop combined with the use of the wide transparency window of crystalline materials enable this approach to be readily applicable to diode lasers emitting in other regions of the electromagnetic spectrum, especially in the UV and mid-IR.

  11. Rapid Bacterial Detection via an All-Electronic CMOS Biosensor

    PubMed Central

    Nikkhoo, Nasim; Cumby, Nichole; Gulak, P. Glenn; Maxwell, Karen L.

    2016-01-01

    The timely and accurate diagnosis of infectious diseases is one of the greatest challenges currently facing modern medicine. The development of innovative techniques for the rapid and accurate identification of bacterial pathogens in point-of-care facilities using low-cost, portable instruments is essential. We have developed a novel all-electronic biosensor that is able to identify bacteria in less than ten minutes. This technology exploits bacteriocins, protein toxins naturally produced by bacteria, as the selective biological detection element. The bacteriocins are integrated with an array of potassium-selective sensors in Complementary Metal Oxide Semiconductor technology to provide an inexpensive bacterial biosensor. An electronic platform connects the CMOS sensor to a computer for processing and real-time visualization. We have used this technology to successfully identify both Gram-positive and Gram-negative bacteria commonly found in human infections. PMID:27618185

  12. DCMB that combines divide-and-conquer and mixed-basis set methods for accurate geometry optimizations, total energies, and vibrational frequencies of large molecules.

    PubMed

    Wu, Anan; Xu, Xin

    2012-06-15

    We present a method, named DCMB, for the calculations of large molecules. It is a combination of a parallel divide-and-conquer (DC) method and a mixed-basis (MB) set scheme. In this approach, atomic forces, total energy and vibrational frequencies are obtained from a series of MB calculations, which are derived from the target system utilizing the DC concept. Unlike the fragmentation based methods, all DCMB calculations are performed over the whole target system and no artificial caps are introduced so that it is particularly useful for charged and/or delocalized systems. By comparing the DCMB results with those from the conventional method, we demonstrate that DCMB is capable of providing accurate prediction of molecular geometries, total energies, and vibrational frequencies of molecules of general interest. We also demonstrate that the high efficiency of the parallel DCMB code holds the promise for a routine geometry optimization of large complex systems.

  13. Thermodynamic theory of epitaxial alloys: first-principles mixed-basis cluster expansion of (In, Ga)N alloy film.

    PubMed

    Liu, Jefferson Zhe; Zunger, Alex

    2009-07-22

    Epitaxial growth of semiconductor alloys onto a fixed substrate has become the method of choice to make high quality crystals. In the coherent epitaxial growth, the lattice mismatch between the alloy film and the substrate induces a particular form of strain, adding a strain energy term into the free energy of the alloy system. Such epitaxial strain energy can alter the thermodynamics of the alloy, leading to a different phase diagram and different atomic microstructures. In this paper, we present a general-purpose mixed-basis cluster expansion method to describe the thermodynamics of an epitaxial alloy, where the formation energy of a structure is expressed in terms of pair and many-body interactions. With a finite number of first-principles calculation inputs, our method can predict the energies of various atomic structures with an accuracy comparable to that of first-principles calculations themselves. Epitaxial (In, Ga)N zinc-blende alloy grown on GaN(001) substrate is taken as an example to demonstrate the details of the method. Two (210) superlattice structures, (InN)(2)/(GaN)(2) (at x = 0.50) and (InN)(4)/(GaN)(1) (at x = 0.80), are identified as the ground state structures, in contrast to the phase-separation behavior of the bulk alloy.

  14. All-electron Hybrid Functional Treatment of Oxides using the FLAPW Method

    NASA Astrophysics Data System (ADS)

    Betzinger, Markus; Schlipf, Martin; Friedrich, Christoph; Ležaić, Marjana; Blügel, Stefan

    2010-03-01

    Hybrid functionals are a practical approximation for the exchange-correlation (xc) functional of density-functional theory. They combine a local or semi-local xc functional with nonlocal Hartree-Fock (HF) exchange and improve the band gap for semiconductors and insulators as well as the description of localized states. So far, most implementations for periodic systems employ a pseudopotential planewave approach. We present an efficient all-electron implementation in the context of the FLAPW methodology realized in the FLEUR (www.flapw.de) code. We report on the implementation of the PBE0 and HSE functionals where an auxiliary basis is constructed from products of LAPW basis functions and used to calculate the HF potential. The Coulomb matrix^1 then has a sparse form. Spatial and time-reversal symmetry is exploited in restricting the Brillouin zone sum in the nonlocal potential to an irreducible wedge. We give account on the efficiency of our concept and of the convergence of the self-consistency cycle. Finally we present results for a variety of oxides and compare those to results obtained with functionals based on the generalized gradient approximation. [1] Comput. Phys. Comm. 180, 347 (2009)

  15. Basis set limit and systematic errors in local-orbital based all-electron DFT

    NASA Astrophysics Data System (ADS)

    Blum, Volker; Behler, Jörg; Gehrke, Ralf; Reuter, Karsten; Scheffler, Matthias

    2006-03-01

    With the advent of efficient integration schemes,^1,2 numeric atom-centered orbitals (NAO's) are an attractive basis choice in practical density functional theory (DFT) calculations of nanostructured systems (surfaces, clusters, molecules). Though all-electron, the efficiency of practical implementations promises to be on par with the best plane-wave pseudopotential codes, while having a noticeably higher accuracy if required: Minimal-sized effective tight-binding like calculations and chemically accurate all-electron calculations are both possible within the same framework; non-periodic and periodic systems can be treated on equal footing; and the localized nature of the basis allows in principle for O(N)-like scaling. However, converging an observable with respect to the basis set is less straightforward than with competing systematic basis choices (e.g., plane waves). We here investigate the basis set limit of optimized NAO basis sets in all-electron calculations, using as examples small molecules and clusters (N2, Cu2, Cu4, Cu10). meV-level total energy convergence is possible using <=50 basis functions per atom in all cases. We also find a clear correlation between the errors which arise from underconverged basis sets, and the system geometry (interatomic distance). ^1 B. Delley, J. Chem. Phys. 92, 508 (1990), ^2 J.M. Soler et al., J. Phys.: Condens. Matter 14, 2745 (2002).

  16. NMR shieldings from density functional perturbation theory: GIPAW versus all-electron calculations

    NASA Astrophysics Data System (ADS)

    de Wijs, G. A.; Laskowski, R.; Blaha, P.; Havenith, R. W. A.; Kresse, G.; Marsman, M.

    2017-02-01

    We present a benchmark of the density functional linear response calculation of NMR shieldings within the gauge-including projector-augmented-wave method against all-electron augmented-plane-wave+local-orbital and uncontracted Gaussian basis set results for NMR shieldings in molecular and solid state systems. In general, excellent agreement between the aforementioned methods is obtained. Scalar relativistic effects are shown to be quite large for nuclei in molecules in the deshielded limit. The small component makes up a substantial part of the relativistic corrections.

  17. Improved Segmented All-Electron Relativistically Contracted Basis Sets for the Lanthanides.

    PubMed

    Aravena, Daniel; Neese, Frank; Pantazis, Dimitrios A

    2016-03-08

    Improved versions of the segmented all-electron relativistically contracted (SARC) basis sets for the lanthanides are presented. The second-generation SARC2 basis sets maintain efficient construction of their predecessors and their individual adaptation to the DKH2 and ZORA Hamiltonians, but feature exponents optimized with a completely new orbital shape fitting procedure and a slightly expanded f space that results in sizable improvement in CASSCF energies and in significantly more accurate prediction of spin-orbit coupling parameters. Additionally, an extended set of polarization/correlation functions is constructed that is appropriate for multireference correlated calculations and new auxiliary basis sets for use in resolution-of-identity (density-fitting) approximations in combination with both DFT and wave function based treatments. Thus, the SARC2 basis sets extend the applicability of the first-generation DFT-oriented basis sets to routine all-electron wave function-based treatments of lanthanide complexes. The new basis sets are benchmarked with respect to excitation energies, radial distribution functions, optimized geometries, orbital eigenvalues, ionization potentials, and spin-orbit coupling parameters of lanthanide systems and are shown to be suitable for the description of magnetic and spectroscopic properties using both DFT and multireference wave function-based methods.

  18. Advancing Efficient All-Electron Electronic Structure Methods Based on Numeric Atom-Centered Orbitals for Energy Related Materials

    NASA Astrophysics Data System (ADS)

    Blum, Volker

    This talk describes recent advances of a general, efficient, accurate all-electron electronic theory approach based on numeric atom-centered orbitals; emphasis is placed on developments related to materials for energy conversion and their discovery. For total energies and electron band structures, we show that the overall accuracy is on par with the best benchmark quality codes for materials, but scalable to large system sizes (1,000s of atoms) and amenable to both periodic and non-periodic simulations. A recent localized resolution-of-identity approach for the Coulomb operator enables O (N) hybrid functional based descriptions of the electronic structure of non-periodic and periodic systems, shown for supercell sizes up to 1,000 atoms; the same approach yields accurate results for many-body perturbation theory as well. For molecular systems, we also show how many-body perturbation theory for charged and neutral quasiparticle excitation energies can be efficiently yet accurately applied using basis sets of computationally manageable size. Finally, the talk highlights applications to the electronic structure of hybrid organic-inorganic perovskite materials, as well as to graphene-based substrates for possible future transition metal compound based electrocatalyst materials. All methods described here are part of the FHI-aims code. VB gratefully acknowledges contributions by numerous collaborators at Duke University, Fritz Haber Institute Berlin, TU Munich, USTC Hefei, Aalto University, and many others around the globe.

  19. Orbit-orbit relativistic correction calculated with all-electron molecular explicitly correlated Gaussians

    NASA Astrophysics Data System (ADS)

    Stanke, Monika; Palikot, Ewa; KÈ©dziera, Dariusz; Adamowicz, Ludwik

    2016-12-01

    An algorithm for calculating the first-order electronic orbit-orbit magnetic interaction correction for an electronic wave function expanded in terms of all-electron explicitly correlated molecular Gaussian (ECG) functions with shifted centers is derived and implemented. The algorithm is tested in calculations concerning the H2 molecule. It is also applied in calculations for LiH and H3+ molecular systems. The implementation completes our work on the leading relativistic correction for ECGs and paves the way for very accurate ECG calculations of ground and excited potential energy surfaces (PESs) of small molecules with two and more nuclei and two and more electrons, such as HeH-, H3+, HeH2, and LiH2+. The PESs will be used to determine rovibrational spectra of the systems.

  20. Near-edge structures from first principles all-electron Bethe-Salpeter equation calculations.

    PubMed

    Olovsson, W; Tanaka, I; Puschnig, P; Ambrosch-Draxl, C

    2009-03-11

    We obtain x-ray absorption near-edge structures (XANES) by solving the equation of motion for the two-particle Green's function for the electron-hole pair, the Bethe-Salpeter equation (BSE), within the all-electron full-potential linearized augmented plane wave method (FPLAPW). The excited states are calculated for the Li K-edge in the insulating solids LiF, Li(2)O and Li(2)S, and absorption spectra are compared with independent particle results using the random phase approximation (RPA), as well as supercell calculations using the core-hole approximation within density functional theory (DFT). The binding energies of strongly bound excitations are determined in the materials, and core-exciton wavefunctions are demonstrated for LiF.

  1. Self-consistent GW: All-electron implementation with localized basis functions

    NASA Astrophysics Data System (ADS)

    Caruso, Fabio; Rinke, Patrick; Ren, Xinguo; Rubio, Angel; Scheffler, Matthias

    2013-08-01

    This paper describes an all-electron implementation of the self-consistent GW (sc-GW) approach—i.e., based on the solution of the Dyson equation—in an all-electron numeric atom-centered orbital basis set. We cast Hedin's equations into a matrix form that is suitable for numerical calculations by means of (i) the resolution-of-identity technique to handle four-center integrals and (ii) a basis representation for the imaginary-frequency dependence of dynamical operators. In contrast to perturbative G0W0, sc-GW provides a consistent framework for ground- and excited-state properties and facilitates an unbiased assessment of the GW approximation. For excited states, we benchmark sc-GW for five molecules relevant for organic photovoltaic applications: thiophene, benzothiazole, 1,2,5-thiadiazole, naphthalene, and tetrathiafulvalene. At self-consistency, the quasiparticle energies are found to be in good agreement with experiment and, on average, more accurate than G0W0 based on Hartree-Fock or density-functional theory with the Perdew-Burke-Ernzerhof exchange-correlation functional. Based on the Galitskii-Migdal total energy, structural properties are investigated for a set of diatomic molecules. For binding energies, bond lengths, and vibrational frequencies sc-GW and G0W0 achieve a comparable performance, which is, however, not as good as that of exact-exchange plus correlation in the random-phase approximation and its advancement to renormalized second-order perturbation theory. Finally, the improved description of dipole moments for a small set of diatomic molecules demonstrates the quality of the sc-GW ground-state density.

  2. All-electron Kohn-Sham density functional theory on hierarchic finite element spaces

    NASA Astrophysics Data System (ADS)

    Schauer, Volker; Linder, Christian

    2013-10-01

    In this work, a real space formulation of the Kohn-Sham equations is developed, making use of the hierarchy of finite element spaces from different polynomial order. The focus is laid on all-electron calculations, having the highest requirement onto the basis set, which must be able to represent the orthogonal eigenfunctions as well as the electrostatic potential. A careful numerical analysis is performed, which points out the numerical intricacies originating from the singularity of the nuclei and the necessity for approximations in the numerical setting, with the ambition to enable solutions within a predefined accuracy. In this context the influence of counter-charges in the Poisson equation, the requirement of a finite domain size, numerical quadratures and the mesh refinement are examined as well as the representation of the electrostatic potential in a high order finite element space. The performance and accuracy of the method is demonstrated in computations on noble gases. In addition the finite element basis proves its flexibility in the calculation of the bond-length as well as the dipole moment of the carbon monoxide molecule.

  3. Large-scale All-electron Density Functional Theory Calculations using Enriched Finite Element Method

    NASA Astrophysics Data System (ADS)

    Kanungo, Bikash; Gavini, Vikram

    We present a computationally efficient method to perform large-scale all-electron density functional theory calculations by enriching the Lagrange polynomial basis in classical finite element (FE) discretization with atom-centered numerical basis functions, which are obtained from the solutions of the Kohn-Sham (KS) problem for single atoms. We term these atom-centered numerical basis functions as enrichment functions. The integrals involved in the construction of the discrete KS Hamiltonian and overlap matrix are computed using an adaptive quadrature grid based on gradients in the enrichment functions. Further, we propose an efficient scheme to invert the overlap matrix by exploiting its LDL factorization and employing spectral finite elements along with Gauss-Lobatto quadrature rules. Finally, we use a Chebyshev polynomial based acceleration technique to compute the occupied eigenspace in each self-consistent iteration. We demonstrate the accuracy, efficiency and scalability of the proposed method on various metallic and insulating benchmark systems, with systems ranging in the order of 10,000 electrons. We observe a 50-100 fold reduction in the overall computational time when compared to classical FE calculations while being commensurate with the desired chemical accuracy. We acknowledge the support of NSF (Grant No. 1053145) and ARO (Grant No. W911NF-15-1-0158) in conducting this work.

  4. All-electron Kohn–Sham density functional theory on hierarchic finite element spaces

    SciTech Connect

    Schauer, Volker; Linder, Christian

    2013-10-01

    In this work, a real space formulation of the Kohn–Sham equations is developed, making use of the hierarchy of finite element spaces from different polynomial order. The focus is laid on all-electron calculations, having the highest requirement onto the basis set, which must be able to represent the orthogonal eigenfunctions as well as the electrostatic potential. A careful numerical analysis is performed, which points out the numerical intricacies originating from the singularity of the nuclei and the necessity for approximations in the numerical setting, with the ambition to enable solutions within a predefined accuracy. In this context the influence of counter-charges in the Poisson equation, the requirement of a finite domain size, numerical quadratures and the mesh refinement are examined as well as the representation of the electrostatic potential in a high order finite element space. The performance and accuracy of the method is demonstrated in computations on noble gases. In addition the finite element basis proves its flexibility in the calculation of the bond-length as well as the dipole moment of the carbon monoxide molecule.

  5. Object-oriented Development of an All-electron Gaussian Basis DFT Code for Periodic Systems

    NASA Astrophysics Data System (ADS)

    Alford, John

    2005-03-01

    We report on the construction of an all-electron Gaussian-basis DFT code for systems periodic in one, two, and three dimensions. This is in part a reimplementation of algorithms in the serial code, GTOFF, which has been successfully applied to the study of crystalline solids, surfaces, and ultra-thin films. The current development is being carried out in an object-oriented parallel framework using C++ and MPI. Some rather special aspects of this code are the use of density fitting methodologies and the implementation of a generalized Ewald technique to do lattice summations of Coulomb integrals, which is typically more accurate than multipole methods. Important modules that have already been created will be described, for example, a flexible input parser and storage class that can parse and store generically tagged data (e.g. XML), an easy to use processor communication mechanism, and the integrals package. Though C++ is generally inferior to F77 in terms of optimization, we show that careful redesigning has allowed us to make up the run-time performance difference in the new code. Timing comparisons and scalability features will be presented. The purpose of this reconstruction is to facilitate the inclusion of new physics. Our goal is to study orbital currents using modified gaussian bases and external magnetic field effects in the weak and ultra-strong ( ˜10^5 T) field regimes. This work is supported by NSF-ITR DMR-0218957.

  6. Predicting Pt-195 NMR chemical shift using new relativistic all-electron basis set.

    PubMed

    Paschoal, D; Guerra, C Fonseca; de Oliveira, M A L; Ramalho, T C; Dos Santos, H F

    2016-10-05

    Predicting NMR properties is a valuable tool to assist the experimentalists in the characterization of molecular structure. For heavy metals, such as Pt-195, only a few computational protocols are available. In the present contribution, all-electron Gaussian basis sets, suitable to calculate the Pt-195 NMR chemical shift, are presented for Pt and all elements commonly found as Pt-ligands. The new basis sets identified as NMR-DKH were partially contracted as a triple-zeta doubly polarized scheme with all coefficients obtained from a Douglas-Kroll-Hess (DKH) second-order scalar relativistic calculation. The Pt-195 chemical shift was predicted through empirical models fitted to reproduce experimental data for a set of 183 Pt(II) complexes which NMR sign ranges from -1000 to -6000 ppm. Furthermore, the models were validated using a new set of 75 Pt(II) complexes, not included in the descriptive set. The models were constructed using non-relativistic Hamiltonian at density functional theory (DFT-PBEPBE) level with NMR-DKH basis set for all atoms. For the best model, the mean absolute deviation (MAD) and the mean relative deviation (MRD) were 150 ppm and 6%, respectively, for the validation set (75 Pt-complexes) and 168 ppm (MAD) and 5% (MRD) for all 258 Pt(II) complexes. These results were comparable with relativistic DFT calculation, 200 ppm (MAD) and 6% (MRD). © 2016 Wiley Periodicals, Inc.

  7. Optical properties of alkali halide crystals from all-electron hybrid TD-DFT calculations

    SciTech Connect

    Webster, R. Harrison, N. M.; Bernasconi, L.

    2015-06-07

    We present a study of the electronic and optical properties of a series of alkali halide crystals AX, with A = Li, Na, K, Rb and X = F, Cl, Br based on a recent implementation of hybrid-exchange time-dependent density functional theory (TD-DFT) (TD-B3LYP) in the all-electron Gaussian basis set code CRYSTAL. We examine, in particular, the impact of basis set size and quality on the prediction of the optical gap and exciton binding energy. The formation of bound excitons by photoexcitation is observed in all the studied systems and this is shown to be correlated to specific features of the Hartree-Fock exchange component of the TD-DFT response kernel. All computed optical gaps and exciton binding energies are however markedly below estimated experimental and, where available, 2-particle Green’s function (GW-Bethe-Salpeter equation, GW-BSE) values. We attribute this reduced exciton binding to the incorrect asymptotics of the B3LYP exchange correlation ground state functional and of the TD-B3LYP response kernel, which lead to a large underestimation of the Coulomb interaction between the excited electron and hole wavefunctions. Considering LiF as an example, we correlate the asymptotic behaviour of the TD-B3LYP kernel to the fraction of Fock exchange admixed in the ground state functional c{sub HF} and show that there exists one value of c{sub HF} (∼0.32) that reproduces at least semi-quantitatively the optical gap of this material.

  8. Optical properties of alkali halide crystals from all-electron hybrid TD-DFT calculations.

    PubMed

    Webster, R; Bernasconi, L; Harrison, N M

    2015-06-07

    We present a study of the electronic and optical properties of a series of alkali halide crystals AX, with A = Li, Na, K, Rb and X = F, Cl, Br based on a recent implementation of hybrid-exchange time-dependent density functional theory (TD-DFT) (TD-B3LYP) in the all-electron Gaussian basis set code CRYSTAL. We examine, in particular, the impact of basis set size and quality on the prediction of the optical gap and exciton binding energy. The formation of bound excitons by photoexcitation is observed in all the studied systems and this is shown to be correlated to specific features of the Hartree-Fock exchange component of the TD-DFT response kernel. All computed optical gaps and exciton binding energies are however markedly below estimated experimental and, where available, 2-particle Green's function (GW-Bethe-Salpeter equation, GW-BSE) values. We attribute this reduced exciton binding to the incorrect asymptotics of the B3LYP exchange correlation ground state functional and of the TD-B3LYP response kernel, which lead to a large underestimation of the Coulomb interaction between the excited electron and hole wavefunctions. Considering LiF as an example, we correlate the asymptotic behaviour of the TD-B3LYP kernel to the fraction of Fock exchange admixed in the ground state functional cHF and show that there exists one value of cHF (∼0.32) that reproduces at least semi-quantitatively the optical gap of this material.

  9. Optical properties of alkali halide crystals from all-electron hybrid TD-DFT calculations

    NASA Astrophysics Data System (ADS)

    Webster, R.; Bernasconi, L.; Harrison, N. M.

    2015-06-01

    We present a study of the electronic and optical properties of a series of alkali halide crystals AX, with A = Li, Na, K, Rb and X = F, Cl, Br based on a recent implementation of hybrid-exchange time-dependent density functional theory (TD-DFT) (TD-B3LYP) in the all-electron Gaussian basis set code CRYSTAL. We examine, in particular, the impact of basis set size and quality on the prediction of the optical gap and exciton binding energy. The formation of bound excitons by photoexcitation is observed in all the studied systems and this is shown to be correlated to specific features of the Hartree-Fock exchange component of the TD-DFT response kernel. All computed optical gaps and exciton binding energies are however markedly below estimated experimental and, where available, 2-particle Green's function (GW-Bethe-Salpeter equation, GW-BSE) values. We attribute this reduced exciton binding to the incorrect asymptotics of the B3LYP exchange correlation ground state functional and of the TD-B3LYP response kernel, which lead to a large underestimation of the Coulomb interaction between the excited electron and hole wavefunctions. Considering LiF as an example, we correlate the asymptotic behaviour of the TD-B3LYP kernel to the fraction of Fock exchange admixed in the ground state functional cHF and show that there exists one value of cHF (˜0.32) that reproduces at least semi-quantitatively the optical gap of this material.

  10. Electronic structure of stoichiometric and reduced ZnO from periodic relativistic all electron hybrid density functional calculations using numeric atom-centered orbitals.

    PubMed

    Viñes, Francesc; Illas, Francesc

    2017-03-30

    The atomic and electronic structure of stoichiometric and reduced ZnO wurtzite has been studied using a periodic relativistic all electron hybrid density functional (PBE0) approach and numeric atom-centered orbital basis set with quality equivalent to aug-cc-pVDZ. To assess the importance of relativistic effects, calculations were carried out without and with explicit inclusion of relativistic effects through the zero order regular approximation. The calculated band gap is ∼0.2 eV smaller than experiment, close to previous PBE0 results including relativistic calculation through the pseudopotential and ∼0.25 eV smaller than equivalent nonrelativistic all electron PBE0 calculations indicating possible sources of error in nonrelativistic all electron density functional calculations for systems containing elements with relatively high atomic number. The oxygen vacancy formation energy converges rather fast with the supercell size, the predicted value agrees with previously hybrid density functional calculations and analysis of the electronic structure evidences the presence of localized electrons at the vacancy site with a concomitant well localized peak in the density of states ∼0.5 eV above the top of the valence band and a significant relaxation of the Zn atoms near to the oxygen vacancy. Finally, present work shows that accurate results can be obtained in systems involving large supercells containing up to ∼450 atoms using a numeric atomic-centered orbital basis set within a full all electron description including scalar relativistic effects at an affordable cost. © 2017 Wiley Periodicals, Inc.

  11. exciting: a full-potential all-electron package implementing density-functional theory and many-body perturbation theory

    NASA Astrophysics Data System (ADS)

    Gulans, Andris; Kontur, Stefan; Meisenbichler, Christian; Nabok, Dmitrii; Pavone, Pasquale; Rigamonti, Santiago; Sagmeister, Stephan; Werner, Ute; Draxl, Claudia

    2014-09-01

    Linearized augmented planewave methods are known as the most precise numerical schemes for solving the Kohn-Sham equations of density-functional theory (DFT). In this review, we describe how this method is realized in the all-electron full-potential computer package, exciting. We emphasize the variety of different related basis sets, subsumed as (linearized) augmented planewave plus local orbital methods, discussing their pros and cons and we show that extremely high accuracy (microhartrees) can be achieved if the basis is chosen carefully. As the name of the code suggests, exciting is not restricted to ground-state calculations, but has a major focus on excited-state properties. It includes time-dependent DFT in the linear-response regime with various static and dynamical exchange-correlation kernels. These are preferably used to compute optical and electron-loss spectra for metals, molecules and semiconductors with weak electron-hole interactions. exciting makes use of many-body perturbation theory for charged and neutral excitations. To obtain the quasi-particle band structure, the GW approach is implemented in the single-shot approximation, known as G0W0. Optical absorption spectra for valence and core excitations are handled by the solution of the Bethe-Salpeter equation, which allows for the description of strongly bound excitons. Besides these aspects concerning methodology, we demonstrate the broad range of possible applications by prototypical examples, comprising elastic properties, phonons, thermal-expansion coefficients, dielectric tensors and loss functions, magneto-optical Kerr effect, core-level spectra and more.

  12. Exciting: a full-potential all-electron package implementing density-functional theory and many-body perturbation theory.

    PubMed

    Gulans, Andris; Kontur, Stefan; Meisenbichler, Christian; Nabok, Dmitrii; Pavone, Pasquale; Rigamonti, Santiago; Sagmeister, Stephan; Werner, Ute; Draxl, Claudia

    2014-09-10

    Linearized augmented planewave methods are known as the most precise numerical schemes for solving the Kohn-Sham equations of density-functional theory (DFT). In this review, we describe how this method is realized in the all-electron full-potential computer package, exciting. We emphasize the variety of different related basis sets, subsumed as (linearized) augmented planewave plus local orbital methods, discussing their pros and cons and we show that extremely high accuracy (microhartrees) can be achieved if the basis is chosen carefully. As the name of the code suggests, exciting is not restricted to ground-state calculations, but has a major focus on excited-state properties. It includes time-dependent DFT in the linear-response regime with various static and dynamical exchange-correlation kernels. These are preferably used to compute optical and electron-loss spectra for metals, molecules and semiconductors with weak electron-hole interactions. exciting makes use of many-body perturbation theory for charged and neutral excitations. To obtain the quasi-particle band structure, the GW approach is implemented in the single-shot approximation, known as G(0)W(0). Optical absorption spectra for valence and core excitations are handled by the solution of the Bethe-Salpeter equation, which allows for the description of strongly bound excitons. Besides these aspects concerning methodology, we demonstrate the broad range of possible applications by prototypical examples, comprising elastic properties, phonons, thermal-expansion coefficients, dielectric tensors and loss functions, magneto-optical Kerr effect, core-level spectra and more.

  13. Toward Accurate Modelling of Enzymatic Reactions: All Electron Quantum Chemical Analysis combined with QM/MM Calculation of Chorismate Mutase

    NASA Astrophysics Data System (ADS)

    Ishida, Toyokazu

    2008-09-01

    To further understand the catalytic role of the protein environment in the enzymatic process, the author has analyzed the reaction mechanism of the Claisen rearrangement of Bacillus subtilis chorismate mutase (BsCM). By introducing a new computational strategy that combines all-electron QM calculations with ab initio QM/MM modelings, it was possible to simulate the molecular interactions between the substrate and the protein environment. The electrostatic nature of the transition state stabilization was characterized by performing all-electron QM calculations based on the fragment molecular orbital technique for the entire enzyme.

  14. Toward Accurate Modelling of Enzymatic Reactions: All Electron Quantum Chemical Analysis combined with QM/MM Calculation of Chorismate Mutase

    SciTech Connect

    Ishida, Toyokazu

    2008-09-17

    To further understand the catalytic role of the protein environment in the enzymatic process, the author has analyzed the reaction mechanism of the Claisen rearrangement of Bacillus subtilis chorismate mutase (BsCM). By introducing a new computational strategy that combines all-electron QM calculations with ab initio QM/MM modelings, it was possible to simulate the molecular interactions between the substrate and the protein environment. The electrostatic nature of the transition state stabilization was characterized by performing all-electron QM calculations based on the fragment molecular orbital technique for the entire enzyme.

  15. Efficient O(N) integration for all-electron electronic structure calculation using numeric basis functions

    SciTech Connect

    Havu, V. Blum, V.; Havu, P.; Scheffler, M.

    2009-12-01

    We consider the problem of developing O(N) scaling grid-based operations needed in many central operations when performing electronic structure calculations with numeric atom-centered orbitals as basis functions. We outline the overall formulation of localized algorithms, and specifically the creation of localized grid batches. The choice of the grid partitioning scheme plays an important role in the performance and memory consumption of the grid-based operations. Three different top-down partitioning methods are investigated, and compared with formally more rigorous yet much more expensive bottom-up algorithms. We show that a conceptually simple top-down grid partitioning scheme achieves essentially the same efficiency as the more rigorous bottom-up approaches.

  16. Large-scale all-electron density functional theory calculations using an enriched finite-element basis

    NASA Astrophysics Data System (ADS)

    Kanungo, Bikash; Gavini, Vikram

    2017-01-01

    We present a computationally efficient approach to perform large-scale all-electron density functional theory calculations by enriching the classical finite element basis with compactly supported atom-centered numerical basis functions that are constructed from the solution of the Kohn-Sham (KS) problem for single atoms. We term these numerical basis functions as enrichment functions, and the resultant basis as the enriched finite element basis. The compact support for the enrichment functions is obtained by using smooth cutoff functions, which enhances the conditioning and maintains the locality of the enriched finite element basis. The integrals involved in the evaluation of the discrete KS Hamiltonian and overlap matrix in the enriched finite element basis are computed using an adaptive quadrature grid that is constructed based on the characteristics of enrichment functions. Further, we propose an efficient scheme to invert the overlap matrix by using a blockwise matrix inversion in conjunction with special reduced-order quadrature rules, which is required to transform the discrete Kohn-Sham problem to a standard eigenvalue problem. Finally, we solve the resulting standard eigenvalue problem, in each self-consistent field iteration, by using a Chebyshev polynomial based filtering technique to compute the relevant eigenspectrum. We demonstrate the accuracy, efficiency, and parallel scalability of the proposed method on semiconducting and heavy-metallic systems of various sizes, with the largest system containing 8694 electrons. We obtain accuracies in the ground-state energies that are ˜1 mHa with reference ground-state energies employing classical finite element as well as Gaussian basis sets. Using the proposed formulation based on enriched finite element basis, for accuracies commensurate with chemical accuracy, we observe a staggering 50 -300 -fold reduction in the overall computational time when compared to classical finite element basis. Further, we find a

  17. Full Parallel Implementation of an All-Electron Four-Component Dirac-Kohn-Sham Program.

    PubMed

    Rampino, Sergio; Belpassi, Leonardo; Tarantelli, Francesco; Storchi, Loriano

    2014-09-09

    A full distributed-memory implementation of the Dirac-Kohn-Sham (DKS) module of the program BERTHA (Belpassi et al., Phys. Chem. Chem. Phys. 2011, 13, 12368-12394) is presented, where the self-consistent field (SCF) procedure is replicated on all the parallel processes, each process working on subsets of the global matrices. The key feature of the implementation is an efficient procedure for switching between two matrix distribution schemes, one (integral-driven) optimal for the parallel computation of the matrix elements and another (block-cyclic) optimal for the parallel linear algebra operations. This approach, making both CPU-time and memory scalable with the number of processors used, virtually overcomes at once both time and memory barriers associated with DKS calculations. Performance, portability, and numerical stability of the code are illustrated on the basis of test calculations on three gold clusters of increasing size, an organometallic compound, and a perovskite model. The calculations are performed on a Beowulf and a BlueGene/Q system.

  18. All-electron formalism for total energy strain derivatives and stress tensor components for numeric atom-centered orbitals

    NASA Astrophysics Data System (ADS)

    Knuth, Franz; Carbogno, Christian; Atalla, Viktor; Blum, Volker; Scheffler, Matthias

    2015-05-01

    We derive and implement the strain derivatives of the total energy of solids, i.e., the analytic stress tensor components, in an all-electron, numeric atom-centered orbital based density-functional formalism. We account for contributions that arise in the semi-local approximation (LDA/GGA) as well as in the generalized Kohn-Sham case, in which a fraction of exact exchange (hybrid functionals) is included. In this work, we discuss the details of the implementation including the numerical corrections for sparse integrations grids which allow to produce accurate results. We validate the implementation for a variety of test cases by comparing to strain derivatives performed via finite differences. Additionally, we include the detailed definition of the overlapping atom-centered integration formalism used in this work to obtain total energies and their derivatives.

  19. All electron quantum chemical calculation of the entire enzyme system confirms a collective catalytic device in the chorismate mutase reaction.

    PubMed

    Ishida, Toyokazu; Fedorov, Dmitri G; Kitaura, Kazuo

    2006-01-26

    To elucidate the catalytic power of enzymes, we analyzed the reaction profile of Claisen rearrangement of Bacillus subtilis chorismate mutase (BsCM) by all electron quantum chemical calculations using the fragment molecular orbital (FMO) method. To the best of our knowledge, this is the first report of ab initio-based quantum chemical calculations of the entire enzyme system, where we provide a detailed analysis of the catalytic factors that accomplish transition-state stabilization (TSS). FMO calculations deliver an ab initio-level estimate of the intermolecular interaction between the substrate and the amino acid residues of the enzyme. To clarify the catalytic role of Arg90, we calculated the reaction profile of the wild-type BsCM as well as Lys90 and Cit90 mutant BsCMs. Structural refinement and the reaction path determination were performed at the ab initio QM/MM level, and FMO calculations were applied to the QM/MM refined structures. Comparison between three types of reactions established two collective catalytic factors in the BsCM reaction: (1) the hydrogen bonds connecting the Glu78-Arg90-substrate cooperatively control the stability of TS relative to the ES complex and (2) the positive charge on Arg90 polarizes the substrate in the TS region to gain more electrostatic stabilization.

  20. All-electronic droplet generation on-chip with real-time feedback control for EWOD digital microfluidics.

    PubMed

    Gong, Jian; Kim, Chang-Jin C J

    2008-06-01

    Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabrication and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1 : x (x < 1) mixing, in comparison to the previously considered n : m mixing (i.e., n and m unit droplets).

  1. All-electron and pseudo-potential studies of structural and electronic properties of Si chains and nanowires

    NASA Astrophysics Data System (ADS)

    Li, Jun; Williamson, Andrew

    2005-03-01

    Recent experimentsootnotetextY. Wu, et.al., Nature 430, 61 (2004); and references therein invoke Si nanowires as promising materials for nanoscale electronic and optical devices. We carried out electronic structure calculations of silicon chains and nanowires, by using both the full-potential linearized augmented plane wave (FLAPW) methodootnotetextE.Wimmer, H.Krakauer, M.Weinert, AJ Freeman, PRB 24, 864 (1981) and the pseudopotential plane wave method. We studied two sets of H-terminated one nanometer silicon wires, one oriented along (001) and the other along(111); both show direct band gaps, with the (111) oriented wires showing a smaller gap (˜2.1 eV) than (001) (˜2.5 eV). This trend differs from that reported in the literature ootnotetextF. Buda, et.al., PRL 69, 1272 (1992); A. M. Saitta, et.al., PRB 53, 1446 (1996), but it is the same in both our all-electron and well converged pseudopotential calculations. We also found that structural relaxations induce different effects on the band structure of differently oriented wires; the band gap change is nearly 0.2 eV between the ideal and relaxed models for (001) while it is negligible for (111) wires.

  2. ALL-ELECTRONIC DROPLET GENERATION ON-CHIP WITH REAL-TIME FEEDBACK CONTROL FOR EWOD DIGITIAL MICROFLUIDICS

    PubMed Central

    Gong, Jian; Kim, Chang-Jin “CJ”

    2009-01-01

    Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabricaion and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1:x (x < 1) mixing, in comparison to the previously considered n:m mixing (i.e., n and m unit droplets). PMID:18497909

  3. Bidirectional effect of magnetic field on electronic thermal transport of metals from all-electron first-principles calculations

    NASA Astrophysics Data System (ADS)

    Yang, Jia-Yue; Yue, Sheng-Ying; Hu, Ming

    2016-12-01

    Considerable discussions have occurred about the critical role played by free electrons in the transport of heat in pure metals. In principle, any environment that can influence the dynamical behaviors of electrons would have impact on electronic thermal conductivity (κel) of metals. Over the past decades, significant progress and comprehensive understanding have been gained from theoretical, as well as experimental, investigations by taking into account the effects of various conditions, typically temperature, impurities, strain, dimensionality, interface, etc. However, the effect of external magnetic field has received less attention. In this paper, the magnetic-field dependence of electron-phonon scattering, the electron's lifetime, and κel of representative metals (Al, Ni, and Nb) are investigated within the framework of all-electron spin-density functional theory. For Al and Ni, the induced magnetization vector field and difference in electron density under external magnetic-field aggregate toward the center of unit cell, leading to the enhanced electron-phonon scattering, the damped electron's lifetime, and thus the reduced κel. On the contrary, for Nb with strong intrinsic electron-phonon interaction, the electron's lifetime and κel slightly increase as external magnetic field is enhanced. This is mainly attributed to the separately distributed magnetization vector field and difference in electron density along the corner of unit cell. This paper sheds light on the origin of influence of external magnetic field on κel for pure metals and offers a new route for robust manipulation of electronic thermal transport via applying external magnetic field.

  4. All-electron KKR Calculations for Metallic Systems with Thousands of Atoms Per Cell via Sparse Matrix Iterative Solvers

    NASA Astrophysics Data System (ADS)

    Khan, Suffian; Johnson, Duane

    2010-03-01

    To perform electronic-structure calculations for inherently large systems, such as a quantum dots with heterogeneous interfaces, we must perform the calculations over very large unit cells (10^4 to 10^8 atoms). KKR methods typically solve for G by direct inversion G-1, with known analytic form. Using a screened, k-space hybrid KKR, we solve Dyson's equation for the Green's function using a reference state via G = Gref [ I - (t - tref) Gref]-1, scattering matrices t and tref are known and the non-Hermitian tensor Gref is chosen for convenience and sparsity [1]. The approach is O(N) for bandgap materials, whereas it is O(N^2) for metals but with a potentially large prefactor. We use Krylov-space solvers to reduce storage and exploit known symmetries. Parallel iterative and energy contour solves are made also. We explore the numerical efficiency and scaling versus atoms per unit cells. [1] Smirnov and Johnson, Comp! ^1Phys. Comm. 148, 74-80 (2002).

  5. All-electron KKR Calculations for Metallic Systems with Thousands of Atoms Per Cell via Sparse Matrix Iterative Solvers

    NASA Astrophysics Data System (ADS)

    Khan, Suffian; Alam, Aftab; Johnson, Duane

    2009-03-01

    To perform electronic-structure calculations for inherently large systems, such as a quantum dots or interfaces like domain walls, we must perform the calculations over very large unit cells (10^4 to 10^8 atoms). For the inverse Green's function G-1, KKR methods typically solve for G by direct inversion. Using a screened, k-space hybrid KKR, we solve Dyson's equation for the Green's function using a reference state via G = Gref [ I - (t - tref) Gref]-1, scattering matrices t and tref are known and the non-Hermitian tensor Gref is chosen for convenience and sparsity [1]. The approach is O(N) for bandgap materials, whereas it is O(N^2) for metals but with a potentially large prefactor. Based upon Sparse Approximate Inverse (or SPAI) technique [2], we generalize the algorithm for complex, non-Hermitian matrices, then use the method as a preconditioner for the inversion to reduce the iteration counts (hence, reduce the prefactor) of the iterative Krylov-space inverses, such as TFQMR, to address large-scale metallic systems. Parallel iterative and energy contour solves are made also. We explore the numerical efficiency and scaling versus atoms per unit cells. [1] Smirnov and Johnson, Comp. Phys. Comm. 148, 74-80 (2002). [2] Grote and Huckle, SIAM J. Sci. Comput. 18, 8

  6. Probing protein environment in an enzymatic process: All-electron quantum chemical analysis combined with ab initio quantum mechanical/molecular mechanical modeling of chorismate mutase

    NASA Astrophysics Data System (ADS)

    Ishida, Toyokazu

    2008-09-01

    In this study, we investigated the electronic character of protein environment in enzymatic processes by performing all-electron QM calculations based on the fragment molecular orbital (FMO) method. By introducing a new computational strategy combining all-electron QM analysis with ab initio QM/MM modeling, we investigated the details of molecular interaction energy between a reactive substrate and amino acid residues at a catalytic site. For a practical application, we selected the chorismate mutase catalyzed reaction as an example. Because the computational time required to perform all-electron QM reaction path searches was very large, we employed the ab initio QM/MM modeling technique to construct reliable reaction profiles and performed all-electron FMO calculations for the selected geometries. The main focus of the paper is to analyze the details of electrostatic stabilization, which is considered to be the major feature of enzymatic catalyses, and to clarify how the electronic structure of proteins is polarized in response to the change in electron distribution of the substrate. By performing interaction energy decomposition analysis from a quantum chemical viewpoint, we clarified the relationship between the location of amino acid residues on the protein domain and the degree of electronic polarization of each residue. In particular, in the enzymatic transition state, Arg7, Glu78, and Arg90 are highly polarized in response to the delocalized electronic character of the substrate, and as a result, a large amount of electrostatic stabilization energy is stored in the molecular interaction between the enzyme and the substrate and supplied for transition state stabilization.

  7. Probing protein environment in an enzymatic process: All-electron quantum chemical analysis combined with ab initio quantum mechanical/molecular mechanical modeling of chorismate mutase.

    PubMed

    Ishida, Toyokazu

    2008-09-28

    In this study, we investigated the electronic character of protein environment in enzymatic processes by performing all-electron QM calculations based on the fragment molecular orbital (FMO) method. By introducing a new computational strategy combining all-electron QM analysis with ab initio QM/MM modeling, we investigated the details of molecular interaction energy between a reactive substrate and amino acid residues at a catalytic site. For a practical application, we selected the chorismate mutase catalyzed reaction as an example. Because the computational time required to perform all-electron QM reaction path searches was very large, we employed the ab initio QM/MM modeling technique to construct reliable reaction profiles and performed all-electron FMO calculations for the selected geometries. The main focus of the paper is to analyze the details of electrostatic stabilization, which is considered to be the major feature of enzymatic catalyses, and to clarify how the electronic structure of proteins is polarized in response to the change in electron distribution of the substrate. By performing interaction energy decomposition analysis from a quantum chemical viewpoint, we clarified the relationship between the location of amino acid residues on the protein domain and the degree of electronic polarization of each residue. In particular, in the enzymatic transition state, Arg7, Glu78, and Arg90 are highly polarized in response to the delocalized electronic character of the substrate, and as a result, a large amount of electrostatic stabilization energy is stored in the molecular interaction between the enzyme and the substrate and supplied for transition state stabilization.

  8. A wavelet-based Projector Augmented-Wave (PAW) method: Reaching frozen-core all-electron precision with a systematic, adaptive and localized wavelet basis set

    NASA Astrophysics Data System (ADS)

    Rangel, T.; Caliste, D.; Genovese, L.; Torrent, M.

    2016-11-01

    We present a Projector Augmented-Wave (PAW) method based on a wavelet basis set. We implemented our wavelet-PAW method as a PAW library in the ABINIT package [http://www.abinit.org] and into BigDFT [http://www.bigdft.org]. We test our implementation in prototypical systems to illustrate the potential usage of our code. By using the wavelet-PAW method, we can simulate charged and special boundary condition systems with frozen-core all-electron precision. Furthermore, our work paves the way to large-scale and potentially order- N simulations within a PAW method.

  9. How localized is ``local?'' Efficiency vs. accuracy of O(N) domain decomposition in local orbital based all-electron electronic structure theory

    NASA Astrophysics Data System (ADS)

    Havu, Vile; Blum, Volker; Scheffler, Matthias

    2007-03-01

    Numeric atom-centered local orbitals (NAO) are efficient basis sets for all-electron electronic structure theory. The locality of NAO's can be exploited to render (in principle) all operations of the self-consistency cycle O(N). This is straightforward for 3D integrals using domain decomposition into spatially close subsets of integration points, enabling critical computational savings that are effective from ˜tens of atoms (no significant overhead for smaller systems) and make large systems (100s of atoms) computationally feasible. Using a new all-electron NAO-based code,^1 we investigate the quantitative impact of exploiting this locality on two distinct classes of systems: Large light-element molecules [Alanine-based polypeptide chains (Ala)n], and compact transition metal clusters. Strict NAO locality is achieved by imposing a cutoff potential with an onset radius rc, and exploited by appropriately shaped integration domains (subsets of integration points). Conventional tight rc<= 3å have no measurable accuracy impact in (Ala)n, but introduce inaccuracies of 20-30 meV/atom in Cun. The domain shape impacts the computational effort by only 10-20 % for reasonable rc. ^1 V. Blum, R. Gehrke, P. Havu, V. Havu, M. Scheffler, The FHI Ab Initio Molecular Simulations (aims) Project, Fritz-Haber-Institut, Berlin (2006).

  10. All-electron molecular Dirac-Hartree-Fock calculations - Properties of the group IV monoxides GeO, SnO, and PbO

    NASA Technical Reports Server (NTRS)

    Dyall, Kenneth G.

    1993-01-01

    Dirac-Hartree-Fock calculations have been carried out on the ground states of the group IV monoxides GeO, SnO and PbO. Geometries, dipole moments and infrared data are presented. For comparison, nonrelativistic, first-order perturbation and relativistic effective core potential calculations have also been carried out. Where appropriate the results are compared with the experimental data and previous calculations. Spin-orbit effects are of great importance for PbO, where first-order perturbation theory including only the mass-velocity and Darwin terms is inadequate to predict the relativistic corrections to the properties. The relativistic effective core potential results show a larger deviation from the all-electron values than for the hydrides, and confirm the conclusions drawn on the basis of the hydride calculations.

  11. Atomic force calculations within the all-electron FLAPW method: Treatment of core states and discontinuities at the muffin-tin sphere boundary

    NASA Astrophysics Data System (ADS)

    Klüppelberg, Daniel A.; Betzinger, Markus; Blügel, Stefan

    2015-01-01

    We analyze the accuracy of the atomic force within the all-electron full-potential linearized augmented plane-wave (FLAPW) method using the force formalism of Yu et al. [Phys. Rev. B 43, 6411 (1991), 10.1103/PhysRevB.43.6411]. A refinement of this formalism is presented that explicitly takes into account the tail of high-lying core states leaking out of the muffin-tin sphere and considers the small discontinuities of LAPW wave function, density, and potential at the muffin-tin sphere boundaries. For MgO and EuTiO3 it is demonstrated that these amendments substantially improve the acoustic sum rule and the symmetry of the force constant matrix. Sum rule and symmetry are realized with an accuracy of μ Htr /aB .

  12. All-electron molecular Dirac-Hartree-Fock calculations: Properties of the group IV monoxides GeO, SnO and PbO

    NASA Technical Reports Server (NTRS)

    Dyall, Kenneth G.

    1991-01-01

    Dirac-Hartree-Fock calculations have been carried out on the ground states of the group IV monoxides GeO, SnO and PbO. Geometries, dipole moments and infrared data are presented. For comparison, nonrelativistic, first-order perturbation and relativistic effective core potential calculations have also been carried out. Where appropriate the results are compared with the experimental data and previous calculations. Spin-orbit effects are of great importance for PbO, where first-order perturbation theory including only the mass-velocity and Darwin terms is inadequate to predict the relativistic corrections to the properties. The relativistic effective core potential results show a larger deviation from the all-electron values than for the hydrides, and confirm the conclusions drawn on the basis of the hydride calculations.

  13. 4-Component correlated all-electron study on Eka-actinium Fluoride (E121F) including Gaunt interaction: Accurate analytical form, bonding and influence on rovibrational spectra

    NASA Astrophysics Data System (ADS)

    Amador, Davi H. T.; de Oliveira, Heibbe C. B.; Sambrano, Julio R.; Gargano, Ricardo; de Macedo, Luiz Guilherme M.

    2016-10-01

    A prolapse-free basis set for Eka-Actinium (E121, Z = 121), numerical atomic calculations on E121, spectroscopic constants and accurate analytical form for the potential energy curve of diatomic E121F obtained at 4-component all-electron CCSD(T) level including Gaunt interaction are presented. The results show a strong and polarized bond (≈181 kcal/mol in strength) between E121 and F, the outermost frontier molecular orbitals from E121F should be fairly similar to the ones from AcF and there is no evidence of break of periodic trends. Moreover, the Gaunt interaction, although small, is expected to influence considerably the overall rovibrational spectra.

  14. Accurate all-electron correlation energies for the closed-shell atoms from Ar to Rn and their relationship to the corresponding MP2 correlation energies.

    PubMed

    McCarthy, Shane P; Thakkar, Ajit J

    2011-01-28

    All-electron correlation energies E(c) are not very well-known for atoms with more than 18 electrons. Hence, coupled-cluster calculations in carefully designed basis sets are combined with fully converged second-order Møller-Plesset perturbation theory (MP2) computations to obtain fairly accurate, nonrelativistic E(c) values for the 12 closed-shell atoms from Ar to Rn. These energies will be useful for the evaluation and parameterization of density functionals. The results show that MP2 overestimates ∣E(c)∣ for heavy atoms. Spin-component scaling of the MP2 correlation energy is used to provide a simple explanation for this overestimation.

  15. An algorithm for nonrelativistic quantum-mechanical finite-nuclear-mass variational calculations of nitrogen atom in L = 0, M = 0 states using all-electrons explicitly correlated Gaussian basis functions.

    PubMed

    Sharkey, Keeper L; Adamowicz, Ludwik

    2014-05-07

    An algorithm for quantum-mechanical nonrelativistic variational calculations of L = 0 and M = 0 states of atoms with an arbitrary number of s electrons and with three p electrons have been implemented and tested in the calculations of the ground (4)S state of the nitrogen atom. The spatial part of the wave function is expanded in terms of all-electrons explicitly correlated Gaussian functions with the appropriate pre-exponential Cartesian angular factors for states with the L = 0 and M = 0 symmetry. The algorithm includes formulas for calculating the Hamiltonian and overlap matrix elements, as well as formulas for calculating the analytic energy gradient determined with respect to the Gaussian exponential parameters. The gradient is used in the variational optimization of these parameters. The Hamiltonian used in the approach is obtained by rigorously separating the center-of-mass motion from the laboratory-frame all-particle Hamiltonian, and thus it explicitly depends on the finite mass of the nucleus. With that, the mass effect on the total ground-state energy is determined.

  16. An algorithm for nonrelativistic quantum-mechanical finite-nuclear-mass variational calculations of nitrogen atom in L = 0, M = 0 states using all-electrons explicitly correlated Gaussian basis functions

    SciTech Connect

    Sharkey, Keeper L.; Adamowicz, Ludwik

    2014-05-07

    An algorithm for quantum-mechanical nonrelativistic variational calculations of L = 0 and M = 0 states of atoms with an arbitrary number of s electrons and with three p electrons have been implemented and tested in the calculations of the ground {sup 4}S state of the nitrogen atom. The spatial part of the wave function is expanded in terms of all-electrons explicitly correlated Gaussian functions with the appropriate pre-exponential Cartesian angular factors for states with the L = 0 and M = 0 symmetry. The algorithm includes formulas for calculating the Hamiltonian and overlap matrix elements, as well as formulas for calculating the analytic energy gradient determined with respect to the Gaussian exponential parameters. The gradient is used in the variational optimization of these parameters. The Hamiltonian used in the approach is obtained by rigorously separating the center-of-mass motion from the laboratory-frame all-particle Hamiltonian, and thus it explicitly depends on the finite mass of the nucleus. With that, the mass effect on the total ground-state energy is determined.

  17. e/a classification of Hume–Rothery Rhombic Triacontahedron-type approximants based on all-electron density functional theory calculations

    SciTech Connect

    Mizutani, U; Inukai, M; Sato, H; Zijlstra, E S; Lin, Q

    2014-05-16

    There are three key electronic parameters in elucidating the physics behind the Hume–Rothery electron concentration rule: the square of the Fermi diameter (2kF)2, the square of the critical reciprocal lattice vector and the electron concentration parameter or the number of itinerant electrons per atom e/a. We have reliably determined these three parameters for 10 Rhombic Triacontahedron-type 2/1–2/1–2/1 (N = 680) and 1/1–1/1–1/1 (N = 160–162) approximants by making full use of the full-potential linearized augmented plane wave-Fourier band calculations based on all-electron density-functional theory. We revealed that the 2/1–2/1–2/1 approximants Al13Mg27Zn45 and Na27Au27Ga31 belong to two different sub-groups classified in terms of equal to 126 and 109 and could explain why they take different e/a values of 2.13 and 1.76, respectively. Among eight 1/1–1/1–1/1 approximants Al3Mg4Zn3, Al9Mg8Ag3, Al21Li13Cu6, Ga21Li13Cu6, Na26Au24Ga30, Na26Au37Ge18, Na26Au37Sn18 and Na26Cd40Pb6, the first two, the second two and the last four compounds were classified into three sub-groups with = 50, 46 and 42; and were claimed to obey the e/a = 2.30, 2.10–2.15 and 1.70–1.80 rules, respectively.

  18. e/a classification of Hume-Rothery Rhombic Triacontahedron-type approximants based on all-electron density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Mizutani, U.; Inukai, M.; Sato, H.; Zijlstra, E. S.; Lin, Q.

    2014-08-01

    There are three key electronic parameters in elucidating the physics behind the Hume-Rothery electron concentration rule: the square of the Fermi diameter (2kF)2, the square of the critical reciprocal lattice vector ? and the electron concentration parameter or the number of itinerant electrons per atom e/a. We have reliably determined these three parameters for 10 Rhombic Triacontahedron-type 2/1-2/1-2/1 (N = 680) and 1/1-1/1-1/1 (N = 160-162) approximants by making full use of the full-potential linearized augmented plane wave-Fourier band calculations based on all-electron density-functional theory. We revealed that the 2/1-2/1-2/1 approximants Al13Mg27Zn45 and Na27Au27Ga31 belong to two different sub-groups classified in terms of ? equal to 126 and 109 and could explain why they take different e/a values of 2.13 and 1.76, respectively. Among eight 1/1-1/1-1/1 approximants Al3Mg4Zn3, Al9Mg8Ag3, Al21Li13Cu6, Ga21Li13Cu6, Na26Au24Ga30, Na26Au37Ge18, Na26Au37Sn18 and Na26Cd40Pb6, the first two, the second two and the last four compounds were classified into three sub-groups with ? = 50, 46 and 42; and were claimed to obey the e/a = 2.30, 2.10-2.15 and 1.70-1.80 rules, respectively.

  19. All-electron self-consistent G W in the Matsubara-time domain: Implementation and benchmarks of semiconductors and insulators

    NASA Astrophysics Data System (ADS)

    Chu, Iek-Heng; Trinastic, Jonathan P.; Wang, Yun-Peng; Eguiluz, Adolfo G.; Kozhevnikov, Anton; Schulthess, Thomas C.; Cheng, Hai-Ping

    2016-03-01

    The G W approximation is a well-known method to improve electronic structure predictions calculated within density functional theory. In this work, we have implemented a computationally efficient G W approach that calculates central properties within the Matsubara-time domain using the modified version of elk, the full-potential linearized augmented plane wave (FP-LAPW) package. Continuous-pole expansion (CPE), a recently proposed analytic continuation method, has been incorporated and compared to the widely used Padé approximation. Full crystal symmetry has been employed for computational speedup. We have applied our approach to 18 well-studied semiconductors/insulators that cover a wide range of band gaps computed at the levels of single-shot G0W0 , partially self-consistent G W0 , and fully self-consistent G W (full-G W ), in conjunction with the diagonal approximation. Our calculations show that G0W0 leads to band gaps that agree well with experiment for the case of simple s -p electron systems, whereas full-G W is required for improving the band gaps in 3 d electron systems. In addition, G W0 almost always predicts larger band gap values compared to full-G W , likely due to the substantial underestimation of screening effects as well as the diagonal approximation. Both the CPE method and Padé approximation lead to similar band gaps for most systems except strontium titantate, suggesting that further investigation into the latter approximation is necessary for strongly correlated systems. Moreover, the calculated cation d band energies suggest that both full-G W and G W0 lead to results in good agreement with experiment. Our computed band gaps serve as important benchmarks for the accuracy of the Matsubara-time G W approach.

  20. All-electron all-virtual spinor space relativistic coupled-cluster calculations for molecules of heavy elements using contracted basis set: Prediction of atomization energy of PbH4*

    NASA Astrophysics Data System (ADS)

    Malli, Gulzari L.; Siegert, Martin; Turner, David P.

    All-electron all-virtual spinor space (AVSS) relativistic second order Møller-Plesset (RMP2), coupled-cluster singles doubles (RCCSD), RCCSD(T) (RCCSD plus the triple excitation correction included perturbationally) calculations are reported for tetrahedral (Td) PbH4 at various bond lengths using our finite contracted universal Gaussian basis set. Our relativistic calculations predict the RMP2, RCCSD, and RCCD(T) molecular correlation energy for PbH4 as -2.2563, -2.1917, and -2.2311 au, respectively. Ours are the first AVSS RMP2, RCCSD, and RCCSD(T) molecular calculations for electron correlation energy of the heavy element molecule PbH4. All-electron AVSS coupled-cluster calculations for the Pb atom are also reported and these were used (in conjunction with the corresponding molecular electron correlation energy calculations for PbH4) to predict atomization energy (Ae) of PbH4 at various levels of coupled-cluster electron correlation. Our predicted atomization energy for PbH4 (at the optimized bond length of 1.749 Å) with our Dirac-Fock, RMP2, RCCSD, and RCCSD(T) calculations is 5.73, 7.27, 11.24, and 11.62 eV, respectively. Neither such relativistic molecular correlation energy nor atomization energy has been reported so far for heavy polyatomic with 86 electrons. Calculation of relativistic molecular correlation energy is no more a nightmare, and bottlenecks are broken for the calculation of relativistic correlation as well as atomization energy for molecules of heavy elements.

  1. When Anatase Nanoparticles Become Bulklike: Properties of Realistic TiO2 Nanoparticles in the 1-6 nm Size Range from All Electron Relativistic Density Functional Theory Based Calculations.

    PubMed

    Lamiel-Garcia, Oriol; Ko, Kyoung Chul; Lee, Jin Yong; Bromley, Stefan T; Illas, Francesc

    2017-03-10

    All electron relativistic density functional theory (DFT) based calculations using numerical atom-centered orbitals have been carried out to explore the relative stability, atomic, and electronic structure of a series of stoichiometric TiO2 anatase nanoparticles explicitly containing up to 1365 atoms as a function of size and morphology. The nanoparticles under scrutiny exhibit octahedral or truncated octahedral structures and span the 1-6 nm diameter size range. Initial structures were obtained using the Wulff construction, thus exhibiting the most stable (101) and (001) anatase surfaces. Final structures were obtained from geometry optimization with full relaxation of all structural parameters using both generalized gradient approximation (GGA) and hybrid density functionals. Results show that, for nanoparticles of a similar size, octahedral and truncated octahedral morphologies have comparable energetic stabilities. The electronic structure properties exhibit a clear trend converging to the bulk values as the size of the nanoparticles increases but with a marked influence of the density functional employed. Our results suggest that electronic structure properties, and hence reactivity, for the largest anatase nanoparticles considered in this study will be similar to those exhibited by even larger mesoscale particles or by bulk systems. Finally, we present compelling evidence that anatase nanoparticles become effectively bulklike when reaching a size of ∼20 nm diameter.

  2. An all-electron density functional theory study of the structure and properties of the neutral and singly charged M12 and M13 clusters: M = Sc-Zn.

    PubMed

    Gutsev, G L; Weatherford, C W; Belay, K G; Ramachandran, B R; Jena, P

    2013-04-28

    The electronic and geometrical structures of the M12 and M13 clusters where M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn along with their singly negatively and positively charged ions are studied using all-electron density functional theory within the generalized gradient approximation. The geometries corresponding to the lowest total energy states of singly and negatively charged ions of V13, Mn12, Co12, Ni13, Cu13, Zn12, and Zn13 are found to be different from the geometries of the corresponding neutral parents. The computed ionization energies of the neutrals, vertical electron detachment energies from the anions, and energies required to remove a single atom from the M13 and M13(+) clusters are in good agreement with experiment. The change in a total spin magnetic moment of the cation or anion with respect to a total spin magnetic moment of the corresponding neutral is consistent with the one-electron model in most cases, i.e., they differ by ±1.0 μ(B). Exceptions are found only for Sc12(-), Ti12(+), Mn12(-), Mn12(+), Fe12(-), Fe13(+), and Co12(+).

  3. Grid-based electronic structure calculations: The tensor decomposition approach

    SciTech Connect

    Rakhuba, M.V.; Oseledets, I.V.

    2016-05-01

    We present a fully grid-based approach for solving Hartree–Fock and all-electron Kohn–Sham equations based on low-rank approximation of three-dimensional electron orbitals. Due to the low-rank structure the total complexity of the algorithm depends linearly with respect to the one-dimensional grid size. Linear complexity allows for the usage of fine grids, e.g. 8192{sup 3} and, thus, cheap extrapolation procedure. We test the proposed approach on closed-shell atoms up to the argon, several molecules and clusters of hydrogen atoms. All tests show systematical convergence with the required accuracy.

  4. An all electronic transportation system from LEO to GEO and beyond

    NASA Technical Reports Server (NTRS)

    Brown, William C.

    1989-01-01

    System description and moon mission interface; LEO to GEO flight times; technology readiness and modular construction; system capacity and costs; and reduction of propellant mass are outlined. This presentation is represented by viewgraph only.

  5. Stress formulation in the all-electron full-potential linearized augmented plane wave method

    NASA Astrophysics Data System (ADS)

    Nagasako, Naoyuki; Oguchi, Tamio

    2012-02-01

    Stress formulation in the linearlized augmented plane wave (LAPW) method has been proposed in 2002 [1] as an extension of the force formulation in the LAPW method [2]. However, pressure calculations only for Al and Si were reported in Ref.[1] and even now stress calculations have not yet been fully established in the LAPW method. In order to make it possible to efficiently relax lattice shape and atomic positions simultaneously and to precisely evaluate the elastic constants in the LAPW method, we reformulate stress formula in the LAPW method with the Soler-Williams representation [3]. Validity of the formulation is tested by comparing the pressure obtained as the trace of stress tensor with that estimated from total energies for a wide variety of material systems. Results show that pressure is estimated within the accuracy of less than 0.1 GPa. Calculations of the shear elastic constant show that the shear components of the stress tensor are also precisely computed with the present formulation [4].[4pt] [1] T. Thonhauser et al., Solid State Commun. 124, 275 (2002).[0pt] [2] R. Yu et al., Phys. Rev. B 43, 6411 (1991).[0pt] [3] J. M. Soler and A. R. Williams, Phys. Rev. B 40, 1560 (1989).[0pt] [4] N. Nagasako and T. Oguchi, J. Phys. Soc. Jpn. 80, 024701 (2011).

  6. Full-resolution autostereoscopic display using an all-electronic tracking/steering system

    NASA Astrophysics Data System (ADS)

    Gaudreau, Jean-Etienne

    2012-03-01

    PolarScreens is developing a new 3D display technology capable of displaying full HD resolution in each eye without the need for glasses. The technology combines a regular backlight, a 120Hz 3D LCD panel, a vertical Patterned active shutter panel and a head tracking system. The technology relies on a 12-sub-pixel wide alternated pattern encoded in the stereo image to follow the head movement. Alternatively for a passive 3D display, the barrier is made of vertical strip Polarizer Film. This can be applied to any full resolution polarized display like iZ3D, Perceiva, or active retarder 3D display. The end result is a full resolution autostereoscopic display with complete head movement freedom. There are no mechanical moving part (like lenticular) or extra active components to steer the correct L/R image to the user's eyes. The new display has the capacity of displaying 2D/3D information on a pixel per pixel base so there is no need for full screen or windowed 2D/3D switchable apparatus.

  7. All-electron G W +Bethe-Salpeter calculations on small molecules

    NASA Astrophysics Data System (ADS)

    Hirose, Daichi; Noguchi, Yoshifumi; Sugino, Osamu

    2015-05-01

    Accuracy of the first-principles G W +Bethe-Salpeter equation (BSE) method is examined for low-energy excited states of small molecules. The standard formalism, which is based on the one-shot G W approximation and the Tamm-Dancoff approximation (TDA), is found to underestimate the optical gap of N2, CO, H2O ,C2H4 , and CH2O by about 1 eV. Possible origins are investigated separately for the effect of TDA and for the approximate schemes of the self-energy operator, which are known to cause overbinding of the electron-hole pair and overscreening of the interaction. By applying the known correction formula, we find the amount of the correction is too small to overcome the underestimated excitation energy. This result indicates a need for fundamental revision of the G W +BSE method rather than adjustment of the standard one. We expect that this study makes the problems in the current G W +BSE formalism clearer and provides useful information for further intrinsic development beyond the current framework.

  8. All-electron GW quasiparticle band structures of group 14 nitride compounds

    NASA Astrophysics Data System (ADS)

    Chu, Iek-Heng; Kozhevnikov, Anton; Schulthess, Thomas C.; Cheng, Hai-Ping

    2014-07-01

    We have investigated the group 14 nitrides (M3N4) in the spinel phase (γ-M3N4 with M = C, Si, Ge, and Sn) and β phase (β-M3N4 with M = Si, Ge, and Sn) using density functional theory with the local density approximation and the GW approximation. The Kohn-Sham energies of these systems have been first calculated within the framework of full-potential linearized augmented plane waves (LAPW) and then corrected using single-shot G0W0 calculations, which we have implemented in the modified version of the Elk full-potential LAPW code. Direct band gaps at the Γ point have been found for spinel-type nitrides γ-M3N4 with M = Si, Ge, and Sn. The corresponding GW-corrected band gaps agree with experiment. We have also found that the GW calculations with and without the plasmon-pole approximation give very similar results, even when the system contains semi-core d electrons. These spinel-type nitrides are novel materials for potential optoelectronic applications because of their direct and tunable band gaps.

  9. All-electron GW quasiparticle band structures of group 14 nitride compounds

    SciTech Connect

    Chu, Iek-Heng; Cheng, Hai-Ping; Kozhevnikov, Anton; Schulthess, Thomas C.

    2014-07-28

    We have investigated the group 14 nitrides (M{sub 3}N{sub 4}) in the spinel phase (γ-M{sub 3}N{sub 4} with M = C, Si, Ge, and Sn) and β phase (β-M{sub 3}N{sub 4} with M = Si, Ge, and Sn) using density functional theory with the local density approximation and the GW approximation. The Kohn-Sham energies of these systems have been first calculated within the framework of full-potential linearized augmented plane waves (LAPW) and then corrected using single-shot G{sub 0}W{sub 0} calculations, which we have implemented in the modified version of the Elk full-potential LAPW code. Direct band gaps at the Γ point have been found for spinel-type nitrides γ-M{sub 3}N{sub 4} with M = Si, Ge, and Sn. The corresponding GW-corrected band gaps agree with experiment. We have also found that the GW calculations with and without the plasmon-pole approximation give very similar results, even when the system contains semi-core d electrons. These spinel-type nitrides are novel materials for potential optoelectronic applications because of their direct and tunable band gaps.

  10. All-electron density functional theory calculations of the zero-pressure properties of plutonium dioxide

    NASA Astrophysics Data System (ADS)

    Boettger, Jonathan C.; Ray, Asok K.

    2000-07-01

    The fluorite structure light-actinide dioxides, uranium dioxide and plutonium dioxide, are both known to be prototypical Mott-Hubbard insulators, with band gaps produced by strong Coulomb correlation effects that are not adequately accounted for in traditional density functional theory (DFT) calculations. Indeed, DFT electronic structure calculations for these two actinide dioxides have been shown to incorrectly predict metallic behavior. The highly-correlated electron effects exhibited by the actinide dioxides, combined with the large relativistic effects (including spin-orbit coupling) expected for any actinide compound, provide an extreme challenge for electronic structure theorists. For this reason, few fully-self-consistent DFT calculations have been carried out for the actinide dioxides, in general, and only one for plutonium dioxide. In that calculation, the troublesome 5f electrons were treated as core electrons, and spin-orbit coupling was ignored.

  11. Using pseudopotentials within the interacting quantum atoms approach.

    PubMed

    Tiana, Davide; Francisco, E; Blanco, M A; Pendás, A Martín

    2009-07-09

    A general strategy to extend the interacting quantum atoms (IQA) approach to pseudopotential or effective core potential electronic structure calculations is presented. With the protocol proposed here, the scope of IQA thinking opens to chemical bonding problems in heavy-atom systems, as well as to larger molecules than those presently allowed by computational limitations. We show that, provided that interatomic surfaces are computed from core-reconstructed densities, reasonable results are obtained by integrating reduced density matrices built from the pseudowave functions. Comparison with all-electron results in a few test systems shows that exchange-correlation energies are better reproduced than Coulombic contributions, an effect which is traced to inadequate atomic populations and leakage of the core population into the surrounding quantum atoms.

  12. A Mixed-Basis Band Structure Interpolation Scheme Applied to the Rocksalt Structure Compounds TiC, TiN and TiO.

    DTIC Science & Technology

    1986-10-15

    I . BaMiltonian of the rocksalt structure is identical to that of the fcc ... structure . 4 The parameters of the NBBSIS for a particular system were determined by applying a nonlinear least squares method1 3 to fit the energy

  13. Some Approaches to Reading.

    ERIC Educational Resources Information Center

    Smith, Nila Banton; Strickland, Ruth

    This pamphlet discusses some beginning approaches and technological approaches to reading instruction, and the relationship between children's language and reading. The first section looks at several approaches to reading instruction: "The Language Experience Approach,""The Initial Teaching Alphabet,""Linguistic Approaches to Reading,""Programed…

  14. Predicting core level binding energies shifts: Suitability of the projector augmented wave approach as implemented in VASP.

    PubMed

    Pueyo Bellafont, Noèlia; Viñes, Francesc; Hieringer, Wolfgang; Illas, Francesc

    2017-03-30

    Here, we assess the accuracy of various approaches implemented in Vienna ab initio simulation package code to estimate core-level binding energy shifts (ΔBEs) using a projector augmented wave method to treat core electrons. The performance of the Perdew-Burke-Ernzerhof (PBE) and the Tao-Perdew-Staroverov-Scuseria (TPSS) exchange-correlation density functionals is examined on a dataset of 68 molecules containing B→F atoms in diverse chemical environments, accounting for 185 different 1s core level binding energy shifts, for which both experimental gas-phase X-ray photoemission (XPS) data and accurate all electron ΔBEs are available. Four procedures to calculate core-level shifts are investigated. Janak-Slater transition state approach yields mean absolute errors of 0.37 (0.21) eV at PBE (TPSS) level, similar to highly accurate all electron ΔSCF approaches using same functionals, and close to XPS experimental accuracy of 0.1 eV. The study supports the use of these procedures to assign ΔBEs of molecular moieties on material surfaces of interest in surface science, nanotechnology, and heterogeneous catalysis. © 2017 Wiley Periodicals, Inc.

  15. Complementary Health Approaches

    MedlinePlus

    ... on some complementary approaches, such as acupuncture and yoga, but there have been fewer studies on other approaches, so much less is known about them. The National Institutes of Health (NIH) is sponsoring research to learn more about ...

  16. Morpheus Surface Approach

    NASA Video Gallery

    This animation shows the Project Morpheus lander flying a kilometer-long simulated surface approach while avoiding hazards in a landing field. The approach takes place at the Shuttle Landing Facili...

  17. Reduced explicitly correlated Hartree-Fock approach within the nuclear-electronic orbital framework: applications to positronic molecular systems.

    PubMed

    Sirjoosingh, Andrew; Pak, Michael V; Swalina, Chet; Hammes-Schiffer, Sharon

    2013-07-21

    In the application of the nuclear-electronic orbital (NEO) method to positronic systems, all electrons and the positron are treated quantum mechanically on the same level. Explicit electron-positron correlation can be included using Gaussian-type geminal functions within the variational self-consistent-field procedure. In this paper, we apply the recently developed reduced explicitly correlated Hartree-Fock (RXCHF) approach to positronic molecular systems. In the application of RXCHF to positronic systems, only a single electronic orbital is explicitly correlated to the positronic orbital. We apply NEO-RXCHF to three systems: positron-lithium, lithium positride, and positron-lithium hydride. For all three of these systems, the RXCHF approach provides accurate two-photon annihilation rates, average contact densities, electronic and positronic single-particle densities, and electron-positron contact densities. Moreover, the RXCHF approach is significantly more accurate than the original XCHF approach, in which all electronic orbitals are explicitly correlated to the positronic orbital in the same manner, because the RXCHF wavefunction is optimized to produce a highly accurate description of the short-ranged electron-positron interaction that dictates the annihilation rates and other local properties. Furthermore, RXCHF methods that neglect or approximate the electronic exchange interactions between the geminal-coupled electronic orbital and the regular electronic orbitals lead to virtually identical annihilation rates and densities as the fully antisymmetric RXCHF method but offer substantial advantages in computational tractability. Thus, NEO-RXCHF is a promising, computationally practical approach for studying larger positron-containing systems.

  18. Molecular geometry and polarizability of small cadmium selenide clusters from all-electron ab initio and Density Functional Theory calculations.

    PubMed

    Karamanis, Panaghiotis; Maroulis, George; Pouchan, Claude

    2006-02-21

    We have calculated molecular geometries and electric polarizabilities for small cadmium selenide clusters. Our calculations were performed with conventional ab initio and density functional theory methods and Gaussian-type basis sets especially designed for (CdSe)(n). We find that the dipole polarizability per atom converges rapidly to the bulk value.

  19. ``If it's not on the Web, it doesn't exist at all'': Electronic Information Resources -- Myth and Reality

    NASA Astrophysics Data System (ADS)

    Stevens-Rayburn, Sarah; Bouton, Ellen N.

    In this paper, we review the current status of astronomical research via electronic means, with an eye towards separating the hype from the hypothetical in hopes of revealing the actual state of affairs. We will review both anecdotal and scholarly work aimed at documenting the state of research using the World Wide Web and demonstrate that although there is enormous potential in electronic research, much of that potential is as yet unrealized. In addition, especially in astronomy, a significant amount of material is not (yet) available electronically and likely will never be. Finally, we will point out the potential danger of a looming paradigm shift in the way astronomers conduct research and the possible consequences thereof. \\end{abstract}

  20. Algorithms for calculating the leading quantum electrodynamics P(1/r 3) correction with all-electron molecular explicitly correlated Gaussians

    NASA Astrophysics Data System (ADS)

    Stanke, Monika; Jurkowski, Jacek; Adamowicz, Ludwik

    2017-03-01

    Algorithms for calculating the quantum electrodynamics Araki–Sucher correction for n-electron explicitly correlated molecular Gaussian functions with shifted centers are derived and implemented. The algorithms are tested in calculations concerning the H2 molecule and applied in ground-state calculations of LiH and {{{H}}}3+ molecules. The implementation will significantly increase the accuracy of the calculations of potential energy surfaces of small diatomic and triatomic molecules and their rovibrational spectra.

  1. Quantum treatment of protons with the reduced explicitly correlated Hartree-Fock approach

    SciTech Connect

    Sirjoosingh, Andrew; Pak, Michael V.; Brorsen, Kurt R.; Hammes-Schiffer, Sharon

    2015-06-07

    The nuclear-electronic orbital (NEO) approach treats select nuclei quantum mechanically on the same level as the electrons and includes nonadiabatic effects between the electrons and the quantum nuclei. The practical implementation of this approach is challenging due to the significance of electron-nucleus dynamical correlation. Herein, we present a general extension of the previously developed reduced NEO explicitly correlated Hartree-Fock (RXCHF) approach, in which only select electronic orbitals are explicitly correlated to each quantum nuclear orbital via Gaussian-type geminal functions. Approximations of the electronic exchange between the geminal-coupled electronic orbitals and the other electronic orbitals are also explored. This general approach enables computationally tractable yet accurate calculations on molecular systems with quantum protons. The RXCHF method is applied to the hydrogen cyanide (HCN) and FHF{sup −} systems, where the proton and all electrons are treated quantum mechanically. For the HCN system, only the two electronic orbitals associated with the CH covalent bond are geminal-coupled to the proton orbital. For the FHF{sup −} system, only the four electronic orbitals associated with the two FH covalent bonds are geminal-coupled to the proton orbital. For both systems, the RXCHF method produces qualitatively accurate nuclear densities, in contrast to mean field-based NEO approaches. The development and implementation of the RXCHF method provide the framework to perform calculations on systems such as proton-coupled electron transfer reactions, where electron-proton nonadiabatic effects are important.

  2. Electronic coupling calculation and pathway analysis of electron transfer reaction using ab initio fragment-based method. I. FMO-LCMO approach

    NASA Astrophysics Data System (ADS)

    Nishioka, Hirotaka; Ando, Koji

    2011-05-01

    By making use of an ab initio fragment-based electronic structure method, fragment molecular orbital-linear combination of MOs of the fragments (FMO-LCMO), developed by Tsuneyuki et al. [Chem. Phys. Lett. 476, 104 (2009)], 10.1016/j.cplett.2009.05.069, we propose a novel approach to describe long-distance electron transfer (ET) in large system. The FMO-LCMO method produces one-electron Hamiltonian of whole system using the output of the FMO calculation with computational cost much lower than conventional all-electron calculations. Diagonalizing the FMO-LCMO Hamiltonian matrix, the molecular orbitals (MOs) of the whole system can be described by the LCMOs. In our approach, electronic coupling TDA of ET is calculated from the energy splitting of the frontier MOs of whole system or perturbation method in terms of the FMO-LCMO Hamiltonian matrix. Moreover, taking into account only the valence MOs of the fragments, we can considerably reduce computational cost to evaluate TDA. Our approach was tested on four different kinds of model ET systems with non-covalent stacks of methane, non-covalent stacks of benzene, trans-alkanes, and alanine polypeptides as their bridge molecules, respectively. As a result, it reproduced reasonable TDA for all cases compared to the reference all-electron calculations. Furthermore, the tunneling pathway at fragment-based resolution was obtained from the tunneling current method with the FMO-LCMO Hamiltonian matrix.

  3. Electronic coupling calculation and pathway analysis of electron transfer reaction using ab initio fragment-based method. I. FMO-LCMO approach.

    PubMed

    Nishioka, Hirotaka; Ando, Koji

    2011-05-28

    By making use of an ab initio fragment-based electronic structure method, fragment molecular orbital-linear combination of MOs of the fragments (FMO-LCMO), developed by Tsuneyuki et al. [Chem. Phys. Lett. 476, 104 (2009)], we propose a novel approach to describe long-distance electron transfer (ET) in large system. The FMO-LCMO method produces one-electron Hamiltonian of whole system using the output of the FMO calculation with computational cost much lower than conventional all-electron calculations. Diagonalizing the FMO-LCMO Hamiltonian matrix, the molecular orbitals (MOs) of the whole system can be described by the LCMOs. In our approach, electronic coupling T(DA) of ET is calculated from the energy splitting of the frontier MOs of whole system or perturbation method in terms of the FMO-LCMO Hamiltonian matrix. Moreover, taking into account only the valence MOs of the fragments, we can considerably reduce computational cost to evaluate T(DA). Our approach was tested on four different kinds of model ET systems with non-covalent stacks of methane, non-covalent stacks of benzene, trans-alkanes, and alanine polypeptides as their bridge molecules, respectively. As a result, it reproduced reasonable T(DA) for all cases compared to the reference all-electron calculations. Furthermore, the tunneling pathway at fragment-based resolution was obtained from the tunneling current method with the FMO-LCMO Hamiltonian matrix.

  4. Endoscopic thyroidectomy: retroauricular approach

    PubMed Central

    Lee, Doh Young; Baek, Seung-Kuk

    2016-01-01

    The incidence of thyroid cancer has abruptly increased recently, with a female predominance. Conventional thyroidectomy using transcervical incision inevitably leaves an unfavorable neck scar; therefore, various extracervical approaches have been introduced to improve cosmetic satisfaction after thyroidectomy. Several reports demonstrated that these extracervical approaches have advantages not only in terms of cosmesis but also in terms of surgical outcomes and postoperative functional preservation. The retroauricular approach has advantages as the dissection area is smaller than that in the transaxillary approach (TA) and surgical anatomy is familiar to the head and neck surgeons. In addition, there is no concern about paresthesia around the nipple or anterior chest, and surgical direction makes central neck dissection easier than with the other extracervical approaches. Herein, we aim to introduce the surgical procedure of retroauricular approach thyroidectomy and present our experiences of postoperative outcomes. PMID:27294041

  5. [Surgical approaches in rhinoplasty].

    PubMed

    Nguyen, P S; Duron, J-B; Bardot, J; Levet, Y; Aiach, G

    2014-12-01

    In the first step of rhinoplasty, the surgical approach will expose through different types of incisions and dissection planes the osteocartilaginous framework of the nasal pyramid prior to performing actions to reduce or increase the latter. This exposure can be performed by a closed approach or by an external approach--the choice depends on the type of nose and the habits of the surgeon. Far from being opposites, closed and external approaches are complementary and should be known and mastered by surgeons performing rhinoplasty.

  6. Pseudopotential-Based Correlation Consistent Composite Approach (rp-ccCA) for First- and Second-Row Transition Metal Thermochemistry.

    PubMed

    Manivasagam, Sivabalan; Laury, Marie L; Wilson, Angela K

    2015-07-02

    The relativistic-pseudopotential correlation consistent composite approach (rp-ccCA) was used to determine the enthalpy of formation (ΔHf) of 24 first row (3d) transition metal compounds. The rp-ccCA-derived ΔHf's were compared to ΔHf's previously obtained with an all-electron composite method for transition metals (ccCA-TM). For the 3d metal systems, rp-ccCA achieves transition metal accuracy, within 3 kcal/mol of reliable experimental data, overall. By utilizing pseudopotentials within the rp-ccCA methodology, we observed a significant computational time savings (53%) in comparison to the all-electron basis sets employed within ccCA-TM. With the proven reliability and accuracy of rp-ccCA, the methodology was employed to construct a calibration set of 210 second-row (4d) transition metal compounds and their ΔHf's. The 4d calibration set is referred to as 4dHf-210. Within the 4dHf-210 set, there were 61 molecules with available experimental data. The average experimental uncertainty was 4.05 kcal/mol and the mean absolute deviation of rp-ccCA was 3.64 kcal/mol, excluding outliers (10 total). This study provides a large set of energetics that can be used to gauge existing and future computational methodologies and to aid experimentalists in reaction design.

  7. Modular Approach for Ethics

    ERIC Educational Resources Information Center

    Wyne, Mudasser F.

    2010-01-01

    It is hard to define a single set of ethics that will cover an entire computer users community. In this paper, the issue is addressed in reference to code of ethics implemented by various professionals, institutes and organizations. The paper presents a higher level model using hierarchical approach. The code developed using this approach could be…

  8. Approaches to Truancy Prevention.

    ERIC Educational Resources Information Center

    Mogulescu, Sara; Segal, Heidi J.

    This report examines how New York counties can systematically and programmatically improve approaches to managing persons in need of supervision (PINS), describing approaches to truancy prevention and diversion that have been instituted nationwide and may be applicable to the PINS operating system. Researchers surveyed truancy-specific programs…

  9. Alternative Approaches to Negotiating.

    ERIC Educational Resources Information Center

    Ramming, Thomas M.

    1997-01-01

    The wait-and-react and laundry-list approaches to combating teachers' collective-bargaining demands are ineffective. An alternative goals-setting approach requires management and the district negotiations team to identify important needs and objectives. West Seneca Central School District ended contentious negotiations by presenting unions with…

  10. The TLC Approach.

    ERIC Educational Resources Information Center

    Welker, William A.

    2002-01-01

    Notes how the author has developed the Teaching and Learning Cues (TLC) approach, an offspring of textbook organizational patterns instruction that stresses the significance of certain words and phrases in reading. Concludes that with the TLC approach, students learn to appreciate the important role cue words and phrases play in understanding…

  11. Approaches to Beginning Reading.

    ERIC Educational Resources Information Center

    Aukerman, Robert C.

    The more than one hundred approaches to initial reading instruction can be grouped under ten headings: basal reader, phonemics, phonemic reading, "linguistics," total language arts, language-experience, one-to-one sound symbol, individualized reading, early reading, and perceptual discrimination. Although the basal reader approach is used in more…

  12. Stuttering-Psycholinguistic Approach

    ERIC Educational Resources Information Center

    Hategan, Carolina Bodea; Anca, Maria; Prihoi, Lacramioara

    2012-01-01

    This research promotes psycholinguistic paradigm, it focusing in delimitating several specific particularities in stuttering pathology. Structural approach, on language sides proves both the recurrent aspects found within specialized national and international literature and the psycholinguistic approaches dependence on the features of the…

  13. Ten practice redesign approaches.

    PubMed

    Slayton, Val

    2013-01-01

    As healthcare delivery continues to evolve at a rapid pace, practices need to consider redesign approaches to stay ahead of the pack. From national policy and private payer initiatives to societal macro trends and the growing use of mobile technologies, delivering value, understanding customer needs, and assessing satisfaction are important elements to achieve and maintain success. This article discusses 10 practice redesign approaches.

  14. Introducing Systems Approaches

    NASA Astrophysics Data System (ADS)

    Reynolds, Martin; Holwell, Sue

    Systems Approaches to Managing Change brings together five systems approaches to managing complex issues, each having a proven track record of over 25 years. The five approaches are: System Dynamics (SD) developed originally in the late 1950s by Jay Forrester Viable Systems Model (VSM) developed originally in the late 1960s by Stafford Beer Strategic Options Development and Analysis (SODA: with cognitive mapping) developed originally in the 1970s by Colin Eden Soft Systems Methodology (SSM) developed originally in the 1970s by Peter Checkland Critical Systems Heuristics (CSH) developed originally in the late 1970s by Werner Ulrich

  15. Otoplasty: A graduated approach.

    PubMed

    Foda, H M

    1999-01-01

    Numerous otoplastic techniques have been described for the correction of protruding ears. Technique selection in otoplasty should be done only after careful analysis of the abnormal anatomy responsible for the protruding ear deformity. A graduated surgical approach is presented which is designed to address all contributing factors to the presenting auricular deformity. The approach starts with the more conservative cartilage-sparing suturing techniques, then proceeds to incorporate other more aggressive cartilage weakening maneuvers. Applying this approach resulted in better long-term results with less postoperative lateralization than that encountered on using the cartilage-sparing techniques alone.

  16. Approaches to Human Communication.

    ERIC Educational Resources Information Center

    Budd, Richard W., Ed.; Ruben, Brent D., Ed.

    This anthology of essays approaches human communication from the points of view of: anthropology, art biology, economics, encounter groups, semantics, general system theory, history, information theory, international behavior, journalism, linguistics, mass media, neurophysiology, nonverbal behavior, organizational behavior, philosophy, political…

  17. SOHO Sees Venus' Approach

    NASA Video Gallery

    This video taken by the Solar and Heliospheric Observatory (SOHO) shows the Sun's corona and Venus' approach for the transit. This was taken with the Extreme ultraviolet Imaging Telescope (EIT) in ...

  18. Tiny Asteroid Approaches Earth

    NASA Video Gallery

    On Oct. 15, 2010, NASA astronomer Rob Suggs captured this view of the tiny asteroid 2010 TG19 as it made its way among the stars of the constellation Pegasus. It will continue to approach during th...

  19. Unconventional approaches to fusion

    SciTech Connect

    Brunelli, B.; Leotta, G.G.

    1982-01-01

    This volume is dedicated to unconventional approaches to fusionthose thermonuclear reactors that, in comparison with Tokamak and other main lines, have received little attention in the worldwide scientific community. Many of the approaches considered are still in the embryonic stages. The authors-an international group of active nuclear scientists and engineers-focus on the parameters achieved in the use of these reactors and on the meaning of the most recent physical studies and their implications for the future. They also compare these approaches with conventional ones, the Tokamak in particular, stressing the non-plasma-physics requirements of fusion reactors. Unconventional compact toroids, linear systems, and multipoles are considered, as are the ''almost conventional'' fusion machines: stellarators, mirrors, reversed-field pinches, and EBT.

  20. Technical approach document

    SciTech Connect

    Not Available

    1989-12-01

    The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law 95-604 (PL95-604), grants the Secretary of Energy the authority and responsibility to perform such actions as are necessary to minimize radiation health hazards and other environmental hazards caused by inactive uranium mill sites. This Technical Approach Document (TAD) describes the general technical approaches and design criteria adopted by the US Department of Energy (DOE) in order to implement remedial action plans (RAPS) and final designs that comply with EPA standards. It does not address the technical approaches necessary for aquifer restoration at processing sites; a guidance document, currently in preparation, will describe aquifer restoration concerns and technical protocols. This document is a second revision to the original document issued in May 1986; the revision has been made in response to changes to the groundwater standards of 40 CFR 192, Subparts A--C, proposed by EPA as draft standards. New sections were added to define the design approaches and designs necessary to comply with the groundwater standards. These new sections are in addition to changes made throughout the document to reflect current procedures, especially in cover design, water resources protection, and alternate site selection; only minor revisions were made to some of the sections. Sections 3.0 is a new section defining the approach taken in the design of disposal cells; Section 4.0 has been revised to include design of vegetated covers; Section 8.0 discusses design approaches necessary for compliance with the groundwater standards; and Section 9.0 is a new section dealing with nonradiological hazardous constituents. 203 refs., 18 figs., 26 tabs.

  1. Financial Management: An Organic Approach

    ERIC Educational Resources Information Center

    Laux, Judy

    2013-01-01

    Although textbooks present corporate finance using a topical approach, good financial management requires an organic approach that integrates the various assignments financial managers confront every day. Breaking the tasks into meaningful subcategories, the current article offers one approach.

  2. Implementation of Communicative Approach

    ERIC Educational Resources Information Center

    Jabeen, Shazi Shah

    2014-01-01

    In the contemporary age of high professional requirements such as excellent communicative skills, the need for successful learning of communicative skills of English language suggests communicative ability to be the goal of language teaching. In other words, to teach English language using communicative approach becomes essential. Studies to…

  3. USEPA WATERSHED APPROACH

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Office of Research and Development has developed a well defined research plan to evaluate pollutants within watersheds. This plan is defined by long term goals and annual performance measures. The first goal is to provide the approache...

  4. Adopting a Pluricentric Approach

    ERIC Educational Resources Information Center

    van Kerckvoorde, Colette

    2012-01-01

    This article argues for a "D-A-CH" approach, which stands for Germany (D), Austria (A), and Switzerland (CH), in language classes from the introductory level on. I begin by tracing the emergence and development of distinct Standard Swiss and Austrian German varieties. I then discuss marketing efforts for Swiss and Austrian German, and…

  5. External approach to rhinoplasty.

    PubMed

    Goodman, Wilfred S; Charbonneau, Paul A

    2015-07-01

    The technique of external rhinoplasty is outlined. Having reviewed 74 cases, its advantages and disadvantages are discussed. Reluctance to use this external approach seems to be based on emotional rather than radical grounds, for its seems to be the procedure of choice for many problems.

  6. NEW APPROACHES: Toppling trains

    NASA Astrophysics Data System (ADS)

    Parry, Malcolm

    1998-03-01

    This article explains a novel way of approaching centripetal force: theory is used to predict an orbital period at which a toy train will topple from a circular track. The demonstration has proved useful in A-level, GNVQ and undergraduate Physics and Engineering schemes.

  7. Approaches to acceptable risk

    SciTech Connect

    Whipple, C.

    1997-04-30

    Several alternative approaches to address the question {open_quotes}How safe is safe enough?{close_quotes} are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made.

  8. Salt repository design approach

    SciTech Connect

    Matthews, S.C.

    1983-01-01

    This paper presents a summary discussion of the approaches that have been and will be taken in design of repository facilities for use with disposal of radioactive wastes in salt formations. Since specific sites have yet to be identified, the discussion is at a general level, supplemented with illustrative examples where appropriate. 5 references, 1 figure.

  9. Marxian Approaches to Education.

    ERIC Educational Resources Information Center

    Carnoy, Martin

    Traditional Marxist approaches to the state relegate superstructural institutions like the school to a minor role in the process of social change. More recent theories like those of Gramsci, Althusser, and Poulantzas raise the state and the class struggle in the state apparatuses to a much more prominent position: superstructure, including the…

  10. New Ideas and Approaches

    ERIC Educational Resources Information Center

    Lukov, V. A.

    2014-01-01

    The article examines theories of youth that have been proposed in the past few years by Russian scientists, and presents the author's original version of a theory of youth that is based on the thesaurus methodological approach. It addresses the ways in which biosocial characteristics may be reflected in new theories of youth.

  11. Dystonia: a clinical approach.

    PubMed

    Edwards, Mark J

    2008-12-01

    Dystonia is a common movement disorder characterised by abnormal postures of the affected body part. It has a very varied presentation and numerous causes, and this can create difficulties with diagnosis and appropriate investigation. This article aims to provide a clinical approach to patients with dystonia, focussing on how to create a differential diagnosis and to plan rational testing.

  12. A Fresh Approach

    ERIC Educational Resources Information Center

    Violino, Bob

    2011-01-01

    Facilities and services are a huge drain on community college budgets. They are also vital to the student experience. As funding dries up across the country, many institutions are taking a team approach, working with partner colleges and private service providers to offset costs and generate revenue without sacrificing the services and amenities…

  13. Islamic approach in counseling.

    PubMed

    Hanin Hamjah, Salasiah; Mat Akhir, Noor Shakirah

    2014-02-01

    A religious approach is one of the matters emphasized in counseling today. Many researchers find that there is a need to apply the religious element in counseling because religion is important in a client's life. The purpose of this research is to identify aspects of the Islamic approach applied in counseling clients by counselors at Pusat Kaunseling Majlis Agama Islam Negeri Sembilan (PKMAINS). In addition, this research also analyses the Islamic approach applied in counseling at PKMAINS with reference to al-Quran and al-Sunnah. This is a qualitative research in the form of case study at PKMAINS. The main method used in this research is interview. The research instrument used is interview protocol. The respondents in this study include 9 counselors who serve in one of the counseling centers in Malaysia. This study also uses questionnaire as an additional instrument, distributed to 36 clients who receive counseling service at the center. The findings of the study show that the Islamic approach applied in counseling at PKMAINS may be categorized into three main aspects: aqidah (faith), ibadah (worship/ultimate devotion and love for God) and akhlaq (moral conduct). Findings also show that the counseling in these aspects is in line with Islamic teachings as contained in al-Quran and al-Sunnah.

  14. SYSTEMS APPROACH TO LEARNING.

    ERIC Educational Resources Information Center

    WIENS, JACOB H.

    TO PERMIT COMPARATIVE ANALYSIS FOR PURPOSES OF EDUCATIONAL PLANNING AT SAN MATEO, FIVE INSTITUTIONS WITH SYSTEMS PROGRAMS ARE EVALUATED ON THE BASIS OF TRIP NOTES. OAKLAND COMMUNITY COLLEGE HAS BEEN COMPLETELY ORGANIZED AROUND THE VOLUNTARY WORK-STUDY LABORATORY APPROACH TO LEARNING. ORAL ROBERTS UNIVERSITY, OKLAHOMA CHRISTIAN COLLEGE, HENRY FORD…

  15. Domain Approach: An Alternative Approach in Moral Education

    ERIC Educational Resources Information Center

    Vengadasalam, Chander; Mamat, Wan Hasmah Wan; Mail, Fauziah; Sudramanian, Munimah

    2014-01-01

    This paper discusses the use of the domain approach in moral education in an upper secondary school in Malaysia. Moral Education needs a creative and an innovative approach. Therefore, a few forms of approaches are used in the teaching-learning of Moral Education. This research describes the use of domain approach which comprises the moral domain…

  16. Approach to hemorrhoids.

    PubMed

    Lohsiriwat, Varut

    2013-07-01

    Hemorrhoids are a very common anorectal disorder defined as the symptomatic enlargement and abnormally downward displacement of anal cushions. The current pathophysiologies of hemorrhoids include the degenerative change of supportive tissue within the anal cushions, vascular hyperplasia, and hyperperfusion of hemorrhoidal plexus. Low-grade hemorrhoids are easily and effectively treated with dietary and lifestyle modification, medical intervention, and some office-based procedures. An operation is usually indicated in symptomatic high-grade and/or complicated hemorrhoids. Whilst hemorrhoidectomy has been the mainstay of surgical treatment, more recently other approaches have been employed including Ligasure hemorrhoidectomy, stapled hemorrhoidopexy, and doppler-guided hemorrhoidal artery ligation. Post-procedural pain and disease recurrence remain the most challenging problems in the treatment of hemorrhoids. This article deals with modern approaches to hemorrhoids based on the latest evidence and reviews of the literature. The management of hemorrhoids in complicated situations is also discussed.

  17. Theoretical Approaches to Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kempa, Krzysztof

    Nanoparticles can be viewed as wave resonators. Involved waves are, for example, carrier waves, plasmon waves, polariton waves, etc. A few examples of successful theoretical treatments that follow this approach are given. In one, an effective medium theory of a nanoparticle composite is presented. In another, plasmon polaritonic solutions allow to extend concepts of radio technology, such as an antenna and a coaxial transmission line, to the visible frequency range.

  18. NEW APPROACHES: Vision underwater

    NASA Astrophysics Data System (ADS)

    Steele, Alan L.

    1997-11-01

    A tutorial type problem examining the focusing performance of the human eye in air and in water is solved by two different approaches. Calculations show that light can be effectively focused on the retina when the eye is in air but not underwater, even with the usual accommodation. We then examine how some vertebrates have accommodation processes that permit them to see effectively both above and below water.

  19. The diesel approach

    SciTech Connect

    Anderson, J.L.

    1993-04-01

    Whether for standby or baseload capacity, diesel generator sets are being used in markets worldwide. Companies are taking a variety of approaches to tapping these markets. The markets for diesel generators follow two basic paths. In the US, they are used primarily for standby or peaking applications. Outside the US, the market includes standby applications but is more often for baseload or prime-power applications.

  20. AVOSS Development Approach

    NASA Technical Reports Server (NTRS)

    Hinton, David A.

    1997-01-01

    A concept is presented for development and implementation of prototype Aircraft Vortex Spacing System (AVOSS). The purpose of the AVOSS is to provide dynamical, weather dependent wake vortex separation criteria to ATC facilities with adequate stability and lead time for use in establishing arrival scheduling. This current paper discusses AVOSS development approach. The discussion includes: system model, AVOSS R&D effort scope, major development issues, concept system development process, AVOSS system testing, and concept demonstration.

  1. Parsec's astrometry direct approaches .

    NASA Astrophysics Data System (ADS)

    Andrei, A. H.

    Parallaxes - and hence the fundamental establishment of stellar distances - rank among the oldest, keyest, and hardest of astronomical determinations. Arguably amongst the most essential too. The direct approach to obtain trigonometric parallaxes, using a constrained set of equations to derive positions, proper motions, and parallaxes, has been labeled as risky. Properly so, because the axis of the parallactic apparent ellipse is smaller than one arcsec even for the nearest stars, and just a fraction of its perimeter can be followed. Thus the classical approach is of linearizing the description by locking the solution to a set of precise positions of the Earth at the instants of observation, rather than to the dynamics of its orbit, and of adopting a close examination of the never many points available. In the PARSEC program the parallaxes of 143 brown dwarfs were aimed at. Five years of observation of the fields were taken with the WIFI camera at the ESO 2.2m telescope, in Chile. The goal is to provide a statistically significant number of trigonometric parallaxes to BD sub-classes from L0 to T7. Taking advantage of the large, regularly spaced, quantity of observations, here we take the risky approach to fit an ellipse in ecliptical observed coordinates and derive the parallaxes. We also combine the solutions from different centroiding methods, widely proven in prior astrometric investigations. As each of those methods assess diverse properties of the PSFs, they are taken as independent measurements, and combined into a weighted least-square general solution.

  2. Three Approaches to Descriptive Research.

    ERIC Educational Resources Information Center

    Svensson, Lennart

    This report compares three approaches to descriptive research, focusing on the kinds of descriptions developed and on the methods used to develop the descriptions. The main emphasis in all three approaches is on verbal data. In these approaches the importance of interpretation and its intuitive nature are emphasized. The three approaches, however,…

  3. Current Approaches to Teaching Reading.

    ERIC Educational Resources Information Center

    Mackintosh, Helen K., Ed.

    Eight approaches to the teaching of elementary reading are described briefly. The Executive Committee of the Department of Elementary-Kindergarten-Nursery Education of the National Education Association selected the approaches to be discussed. They include (1) Language Experience Approach by R. V. Allen, (2) Phonic Approach by Charles E. Wingo,…

  4. Approaches to Quantum Gravity

    NASA Astrophysics Data System (ADS)

    Oriti, Daniele

    2009-03-01

    Preface; Part I. Fundamental Ideas and General Formalisms: 1. Unfinished revolution C. Rovelli; 2. The fundamental nature of space and time G. 't Hooft; 3. Does locality fail at intermediate length scales R. Sorkin; 4. Prolegomena to any future quantum gravity J. Stachel; 5. Spacetime symmetries in histories canonical gravity N. Savvidou; 6. Categorical geometry and the mathematical foundations of quantum gravity L. Crane; 7. Emergent relativity O. Dreyer; 8. Asymptotic safety R. Percacci; 9. New directions in background independent quantum gravity F. Markopoulou; Questions and answers; Part II: 10. Gauge/gravity duality G. Horowitz and J. Polchinski; 11. String theory, holography and quantum gravity T. Banks; 12. String field theory W. Taylor; Questions and answers; Part III: 13. Loop Quantum Gravity T. Thiemann; 14. Covariant loop quantum gravity? E. LIvine; 15. The spin foam representation of loop quantum gravity A. Perez; 16. 3-dimensional spin foam quantum gravity L. Freidel; 17. The group field theory approach to quantum gravity D. Oriti; Questions and answers; Part IV. Discrete Quantum Gravity: 18. Quantum gravity: the art of building spacetime J. Ambjørn, J. Jurkiewicz and R. Loll; 19. Quantum Regge calculations R. Williams; 20. Consistent discretizations as a road to quantum gravity R. Gambini and J. Pullin; 21. The causal set approach to quantum gravity J. Henson; Questions and answers; Part V. Effective Models and Quantum Gravity Phenomenology: 22. Quantum gravity phenomenology G. Amelino-Camelia; 23. Quantum gravity and precision tests C. Burgess; 24. Algebraic approach to quantum gravity II: non-commutative spacetime F. Girelli; 25. Doubly special relativity J. Kowalski-Glikman; 26. From quantum reference frames to deformed special relativity F. Girelli; 27. Lorentz invariance violation and its role in quantum gravity phenomenology J. Collins, A. Perez and D. Sudarsky; 28. Generic predictions of quantum theories of gravity L. Smolin; Questions and

  5. Quantum Approach to Informatics

    NASA Astrophysics Data System (ADS)

    Stenholm, Stig; Suominen, Kalle-Antti

    2005-08-01

    An essential overview of quantum information Information, whether inscribed as a mark on a stone tablet or encoded as a magnetic domain on a hard drive, must be stored in a physical object and thus made subject to the laws of physics. Traditionally, information processing such as computation occurred in a framework governed by laws of classical physics. However, information can also be stored and processed using the states of matter described by non-classical quantum theory. Understanding this quantum information, a fundamentally different type of information, has been a major project of physicists and information theorists in recent years, and recent experimental research has started to yield promising results. Quantum Approach to Informatics fills the need for a concise introduction to this burgeoning new field, offering an intuitive approach for readers in both the physics and information science communities, as well as in related fields. Only a basic background in quantum theory is required, and the text keeps the focus on bringing this theory to bear on contemporary informatics. Instead of proofs and other highly formal structures, detailed examples present the material, making this a uniquely accessible introduction to quantum informatics. Topics covered include: * An introduction to quantum information and the qubit * Concepts and methods of quantum theory important for informatics * The application of information concepts to quantum physics * Quantum information processing and computing * Quantum gates * Error correction using quantum-based methods * Physical realizations of quantum computing circuits A helpful and economical resource for understanding this exciting new application of quantum theory to informatics, Quantum Approach to Informatics provides students and researchers in physics and information science, as well as other interested readers with some scientific background, with an essential overview of the field.

  6. Mitochondrial diseases: therapeutic approaches.

    PubMed

    DiMauro, Salvatore; Mancuso, Michelangelo

    2007-06-01

    Therapy of mitochondrial encephalomyopathies (defined restrictively as defects of the mitochondrial respiratory chain) is woefully inadequate, despite great progress in our understanding of the molecular bases of these disorders. In this review, we consider sequentially several different therapeutic approaches. Palliative therapy is dictated by good medical practice and includes anticonvulsant medication, control of endocrine dysfunction, and surgical procedures. Removal of noxious metabolites is centered on combating lactic acidosis, but extends to other metabolites. Attempts to bypass blocks in the respiratory chain by administration of electron acceptors have not been successful, but this may be amenable to genetic engineering. Administration of metabolites and cofactors is the mainstay of real-life therapy and is especially important in disorders due to primary deficiencies of specific compounds, such as carnitine or coenzyme Q10. There is increasing interest in the administration of reactive oxygen species scavengers both in primary mitochondrial diseases and in neurodegenerative diseases directly or indirectly related to mitochondrial dysfunction. Aerobic exercise and physical therapy prevent or correct deconditioning and improve exercise tolerance in patients with mitochondrial myopathies due to mitochondrial DNA (mtDNA) mutations. Gene therapy is a challenge because of polyplasmy and heteroplasmy, but interesting experimental approaches are being pursued and include, for example, decreasing the ratio of mutant to wild-type mitochondrial genomes (gene shifting), converting mutated mtDNA genes into normal nuclear DNA genes (allotopic expression), importing cognate genes from other species, or correcting mtDNA mutations with specific restriction endonucleases. Germline therapy raises ethical problems but is being considered for prevention of maternal transmission of mtDNA mutations. Preventive therapy through genetic counseling and prenatal diagnosis is

  7. Combined approach brings success.

    PubMed

    Law, Oliver

    2014-06-01

    Sixteen months ago, according to Trumpf Medical Systems, which managed the project, 'something out of the ordinary' happened at Leighton Hospital in Crewe. When making plans to upgrade ageing operating theatres and critical care units, the estates department took the decision to involve other disciplines from the very start of the process. Clinicians, nursing staff, architects, patient representatives, and suppliers, all played their part, with the estates team always at the hub. As Oliver Law, managing director of the UK medical technology specialist, explains, this multidisciplinary approach had a profound effect on the outcome.

  8. [Regenerative approach for COPD].

    PubMed

    Kubo, Hiroshi

    2011-10-01

    No treatment to cure of chronic obstructive pulmonary disease (COPD) is available. Regenerative medicine is one of promising areas for this intractable disease. Several reagents and growth factors are known to promote lung regeneration in small animal models. However, regenerative medicines for human lungs are not achieved yet. Recent advances in stem cell biology and tissue engineering have expanded our understanding of lung endogenous stem cells, and this new knowledge provides us with new ideas for future regenerative therapy for lung diseases. Although lungs are the most challenging organ for regenerative medicine, our cumulative knowledge of lung regeneration and of endogenous progenitor cells makes clear the possibilities for regenerative approach to COPD.

  9. The collaboratory approach

    SciTech Connect

    Peskin, A.M.

    1997-04-01

    A {open_quotes}collaboratory{close_quotes} has been defined as a center without walls, in which researchers can perform their work without regard to geographical location. To an increasing degree, engineering design and development is also taking the form of far-flung collaborations among divisions of a plant, subcontractors, university consultants and customers. It has long been recognized that quality engineering education presents the student with an environment that duplicates as much as possible that which the graduate will encounter in industry. To that end, it is important that engineering schools begin to introduce the collaboratory approach in its preparation, and even use it in delivery of subject matter to students.

  10. Engineering approaches to immunotherapy.

    PubMed

    Swartz, Melody A; Hirosue, Sachiko; Hubbell, Jeffrey A

    2012-08-22

    As the science of immunology grows increasingly mechanistic, motivation for developing quantitative, design-based engineering approaches has also evolved, both for therapeutic interventions and for elucidating immunological pathways in human disease. This has seeded the nascent field of "immunoengineering," which seeks to apply engineering analyses and design approaches to problems in translational immunology. For example, cell engineers are creating ways to tailor and use immune cells as living therapeutics; protein engineers are devising new methods of rapid antibody discovery; biomaterials scientists are guiding vaccine delivery and immune-cell activation with novel constructs; and systems immunologists are deciphering the evolution and maintenance of T and B cell receptor repertoires, which could help guide vaccine design. The field is multidisciplinary and collaborative, with engineers and immunologists working together to better understand and treat disease. We discuss the scientific progress in this young, yet rapidly evolving research area, which has yielded numerous start-up companies that are betting on impact in clinical and commercial translation in the near future.

  11. Modular Approach to Spintronics.

    PubMed

    Camsari, Kerem Yunus; Ganguly, Samiran; Datta, Supriyo

    2015-06-11

    There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this paper is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiment we establish a set of elemental modules representing diverse materials and phenomena. These elemental modules can be integrated seamlessly to model composite devices involving both spintronic and nanomagnetic phenomena. We envision the library of modules to evolve both by incorporating new modules and by improving existing modules as the field progresses. The primary contribution of this paper is to establish the ground rules or protocols for a modular approach that can build a lasting bridge between materials scientists and circuit designers in the field of spintronics and nanomagnetics.

  12. Modular Approach to Spintronics

    PubMed Central

    Camsari, Kerem Yunus; Ganguly, Samiran; Datta, Supriyo

    2015-01-01

    There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this paper is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiment we establish a set of elemental modules representing diverse materials and phenomena. These elemental modules can be integrated seamlessly to model composite devices involving both spintronic and nanomagnetic phenomena. We envision the library of modules to evolve both by incorporating new modules and by improving existing modules as the field progresses. The primary contribution of this paper is to establish the ground rules or protocols for a modular approach that can build a lasting bridge between materials scientists and circuit designers in the field of spintronics and nanomagnetics. PMID:26066079

  13. Breakfast: a multidisciplinary approach

    PubMed Central

    2013-01-01

    Background The role of breakfast as an essential part of an healthy diet has been only recently promoted even if breakfast practices were known since the Middle Age. The growing scientific evidences on this topic are extremely sector-based nevertheless breakfast could be regarded from different point of views and from different expertises. This approach, that take into account history, sociology, anthropology, medicine, psychology and pedagogy, is useful to better understand the value of this meal in our culture. The aim of this paper was to analyse breakfast-related issues based on a multidisciplinary approach with input by specialists from different fields of learning. Discussion Breakfast is now recommended as part of a diet because it is associated with healthier macro- and micronutrient intakes, body mass index and lifestyle. Moreover recent studies showed that breakfast improves cognitive function, intuitive perception and academic performance. Research demonstrates the importance of providing breakfast not only to children but in adults and elderly too. Although the important role breakfast plays in maintaining the health, epidemiological data from industrialised countries reveal that many individuals either eat a nutritionally unhealthy breakfast or skip it completely. Summary The historical, bio-psychological and educational value of breakfast in our culture is extremely important and should be recognized and stressed by the scientific community. Efforts should be done to promote this practice for the individual health and well-being. PMID:23842429

  14. Interstage Flammability Analysis Approach

    NASA Technical Reports Server (NTRS)

    Little, Jeffrey K.; Eppard, William M.

    2011-01-01

    The Interstage of the Ares I launch platform houses several key components which are on standby during First Stage operation: the Reaction Control System (ReCS), the Upper Stage (US) Thrust Vector Control (TVC) and the J-2X with the Main Propulsion System (MPS) propellant feed system. Therefore potentially dangerous leaks of propellants could develop. The Interstage leaks analysis addresses the concerns of localized mixing of hydrogen and oxygen gases to produce deflagration zones in the Interstage of the Ares I launch vehicle during First Stage operation. This report details the approach taken to accomplish the analysis. Specified leakage profiles and actual flammability results are not presented due to proprietary and security restrictions. The interior volume formed by the Interstage walls, bounding interfaces with the Upper and First Stages, and surrounding the J2-X engine was modeled using Loci-CHEM to assess the potential for flammable gas mixtures to develop during First Stage operations. The transient analysis included a derived flammability indicator based on mixture ratios to maintain achievable simulation times. Validation of results was based on a comparison to Interstage pressure profiles outlined in prior NASA studies. The approach proved useful in the bounding of flammability risk in supporting program hazard reviews.

  15. Systemic approaches to biodegradation.

    PubMed

    Trigo, Almudena; Valencia, Alfonso; Cases, Ildefonso

    2009-01-01

    Biodegradation, the ability of microorganisms to remove complex chemicals from the environment, is a multifaceted process in which many biotic and abiotic factors are implicated. The recent accumulation of knowledge about the biochemistry and genetics of the biodegradation process, and its categorization and formalization in structured databases, has recently opened the door to systems biology approaches, where the interactions of the involved parts are the main subject of study, and the system is analysed as a whole. The global analysis of the biodegradation metabolic network is beginning to produce knowledge about its structure, behaviour and evolution, such as its free-scale structure or its intrinsic robustness. Moreover, these approaches are also developing into useful tools such as predictors for compounds' degradability or the assisted design of artificial pathways. However, it is the environmental application of high-throughput technologies from the genomics, metagenomics, proteomics and metabolomics that harbours the most promising opportunities to understand the biodegradation process, and at the same time poses tremendous challenges from the data management and data mining point of view.

  16. Coordinated Parallel Runway Approaches

    NASA Technical Reports Server (NTRS)

    Koczo, Steve

    1996-01-01

    The current air traffic environment in airport terminal areas experiences substantial delays when weather conditions deteriorate to Instrument Meteorological Conditions (IMC). Expected future increases in air traffic will put additional pressures on the National Airspace System (NAS) and will further compound the high costs associated with airport delays. To address this problem, NASA has embarked on a program to address Terminal Area Productivity (TAP). The goals of the TAP program are to provide increased efficiencies in air traffic during the approach, landing, and surface operations in low-visibility conditions. The ultimate goal is to achieve efficiencies of terminal area flight operations commensurate with Visual Meteorological Conditions (VMC) at current or improved levels of safety.

  17. Neuroblastoma: A neurochemical approach

    SciTech Connect

    Schor, N.F. )

    1991-07-01

    Neuroblastoma is among the most common malignancies of childhood. Despite greatly improved therapy for some pediatric tumors, the prognosis for children with metastatic neuroblastoma has not changed significantly in the past 10 years. With conventional chemotherapy, radiation therapy, and surgery, children with metastatic neuroblastoma have a 20% long-term survival rate. The authors describe here approaches to neuroblastoma that target its neuronal characteristics. On the one hand, the neurotransmitter receptors on the surface of the neuroblastoma cells and, on the other hand, specific isozymes that distinguish neuroblastoma cells from their normal counterparts are the focus of these experimental therapies. In the former case, specificity for tumor cells is effected by (1) selective protection of normal neuronal elements from toxicity, or (2) selective potentiation of toxicity for neural tumor cells. It is hoped that these strategies will be generalizable to other neural crest-derived tumors. 32 references.

  18. Population approaches in paediatrics.

    PubMed

    Chatelut, Etienne

    2008-12-01

    Population pharmacokinetic (PK) approach is now often used to evaluate PK characteristics of a new compound during its clinical development. Recently, new legislation governing the development and authorization of medicines for use in children aged 0-17 years was introduced in the European Union. Among the strategies proposed in relation to clinical aspects, use of population PKs is stated. In this manuscript, comparison between standard PK and population PK methods will be briefly addressed to understand why the second is particularly adapted to perform PK studies in paediatrics. Then, specific patients' characteristics (covariates) in paediatrics will be presented. Examples of PK and PK-pharmacodynamic (PK-PD) studies will be finally given. The number of population PK studies published still exceeds largely those of PK-PD.

  19. An environmental approach

    SciTech Connect

    Geerling, C.

    1996-11-01

    The Shell Petroleum Development Company is operating in southern Nigeria in the delta of the Niger River. This delta covers an area 70,000 square kin of coastal ridge barriers, mangroves, freshwater swamp forest and lowland rain forests. Over the past decades considerable changes has occurred through coastal zone modifications, upstream urban and hydrological infrastructure, deforestation, agriculture, fisheries, industrial development, oil operation, as well as demographic changes. The problems associated with these changes are: (1) over-exploitation of renewable natural resources and breakdown of traditional management structures; (2) impact from industry such as pollution and physical changes, and (3) a perception of lack of social and economic equity. This paper describes approaches to help counteract theses problems.

  20. Editorial: Approaching 125.

    PubMed

    Goodman, Sherryl

    2012-02-01

    With this issue, beginning Volume 121, the editorial team shifts from the strong leadership of David Watson to a team under my direction. Approaching 125 years of publication, the Journal of Abnormal Psychology has earned its place as the preeminent outlet for research in psychopathology. With gratitude to the newly assembled team of associate editors (AEs), consulting editors, and ad hoc reviewers, I look forward to guiding the journal through this next term. Nine well-respected scholars have agreed to serve as AEs: Timothy Brown, Laurie Chassin, Jeff Epstein, Jutta Joormann, Pamela Keel, Kate Keenan, Scott Lilienfeld, Angus MacDonald, and Michael Young. The new team is dedicated to working tirelessly to maintain and enhance the journal's esteemed tradition of excellence. Given the well-established strengths of the journal, I will not suggest any fundamental changes.

  1. ATIS - A modular approach

    NASA Astrophysics Data System (ADS)

    Kirson, Allan

    The author describes a modular approach to the design of an in-vehicle navigation and route guidance system that supports a phased implementation of the technology, and anticipates expected differences in implementation in different parts of the world and for different makes and models of vehicle. A series of sensors in the vehicle are used to determine the vehicle's position by dead reckoning and map-matching. The system then calculates the best route to the selected destination, taking into account the real-time traffic information received from a traffic management center, and presents route guidance instructions to the user as the route is traversed. Attention is given to modularity considerations, vehicle positioning, driver support, vehicle-to-infrastructure communications, and the role of standards.

  2. Therapeutic approaches for shankopathies.

    PubMed

    Wang, Xiaoming; Bey, Alexandra L; Chung, Leeyup; Krystal, Andrew D; Jiang, Yong-Hui

    2014-02-01

    Despite recent advances in understanding the molecular mechanisms of autism spectrum disorders (ASD), the current treatments for these disorders are mostly focused on behavioral and educational approaches. The considerable clinical and molecular heterogeneity of ASD present a significant challenge to the development of an effective treatment targeting underlying molecular defects. Deficiency of SHANK family genes causing ASD represent an exciting opportunity for developing molecular therapies because of strong genetic evidence for SHANK as causative genes in ASD and the availability of a panel of Shank mutant mouse models. In this article, we review the literature suggesting the potential for developing therapies based on molecular characteristics and discuss several exciting themes that are emerging from studying Shank mutant mice at the molecular level and in terms of synaptic function.

  3. Television Criticism: A Multifarious Approach.

    ERIC Educational Resources Information Center

    Oseguera, A. Anthony

    Recognizing the need for a multifarious approach to television, this paper provides the reader with the following multidimensional approaches to television criticism: rhetorical, dramatic, literary, cinematic, content analysis, myth, linguistics, semiotics, phenomenalism, phenomenology, interpersonal communication, public relations, image,…

  4. Investigational Approaches for Mesothelioma

    PubMed Central

    Surmont, Veerle F.; van Thiel, Eric R. E.; Vermaelen, Karim; van Meerbeeck, Jan P.

    2011-01-01

    Malignant pleural mesothelioma (MPM) is a rare, aggressive tumor with a poor prognosis. In view of the poor survival benefit from first-line chemotherapy and the lack of subsequent effective treatment options, there is a strong need for the development of more effective treatment approaches for patients with MPM. This review will provide a comprehensive state of the art of new investigational approaches for mesothelioma. In an introductory section, the etiology, epidemiology, natural history, and standard of care treatment for MPM will be discussed. This review provide an update of the major clinical trials that impact mesothelioma treatment, discuss the impact of novel therapeutics, and provide perspective on where the clinical research in mesothelioma is moving. The evidence was collected by a systematic analysis of the literature (2000–2011) using the databases Medline (National Library of Medicine, USA), Embase (Elsevier, Netherlands), Cochrane Library (Great Britain), National Guideline Clearinghouse (USA), HTA Database (International Network of Agencies for Health Technology Assessment – INAHTA), NIH database (USA), International Pleural Mesothelioma Program – WHOLIS (WHO Database), with the following keywords and filters: mesothelioma, guidelines, treatment, surgery, chemotherapy, radiotherapy, review, investigational, drugs. Currently different targeted therapies and biologicals are under investigation for MPM. It is important that the molecular biologic research should first focus on mesothelioma-specific pathways and biomarkers in order to have more effective treatment options for this disease. The use of array technology will be certainly an implicit gain in the identification of new potential prognostic or biomarkers or important pathways in the MPM pathogenesis. Probably a central mesothelioma virtual tissue bank may contribute to the ultimate goal to identify druggable targets and to develop personalized treatment for the MPM patients. PMID

  5. Approaching attometer laser vibrometry

    SciTech Connect

    Rembe, Christian; Kadner, Lisa; Giesen, Moritz

    2014-05-27

    The heterodyne two-beam interferometer has been proven to be the optimal solution for laser-Doppler vibrometry regarding accuracy and signal robustness. The theoretical resolution limit for a two-beam interferometer of laser class 3R (up to 5 mW visible measurement-light) is in the regime of a few femtometer per square-root Hertz and well suited to study vibrations in microstructures. However, some new applications of RF-MEM resonators, nanostructures, and surface-nano-defect detection require resolutions beyond that limit. The resolution depends only on the noise and the sensor sensitivity to specimen displacements. The noise is already defined in nowadays systems by the quantum nature of light for a properly designed optical sensor and more light would lead to an inacceptable influence like heating of a very tiny structure. Thus, noise can only be improved by squeezed-light techniques which require a negligible loss of measurement light which is impossible for almost all technical measurement tasks. Thus, improving the sensitivity is the only possible path which could make attometer laser vibrometry possible. Decreasing the measurement wavelength would increase the sensitivity but would also increase the photon shot noise. In this paper, we discuss an approach to increase the sensitivity by assembling an additional mirror between interferometer and specimen to form an optical cavity. A detailed theoretical analysis of this setup is presented and we derive the resolution limit, discuss the main contributions to the uncertainty budget, and show a first experiment proving the sensitivity amplification of our approach.

  6. A Narrative Approach to Research

    ERIC Educational Resources Information Center

    Bell, Anne

    2003-01-01

    In this paper I present a narrative approach to environmental education research. This approach evolved through a dynamic interplay between research questions, theory, experience, conversation, and reflection. I situate the approach with respect to narrative inquiry and clarify the key conceptual metaphors underpinning my study, including…

  7. Monte Carlo approach to calculate proton stopping in warm dense matter within particle-in-cell simulations

    NASA Astrophysics Data System (ADS)

    Wu, D.; He, X. T.; Yu, W.; Fritzsche, S.

    2017-02-01

    A Monte Carlo approach to proton stopping in warm dense matter is implemented into an existing particle-in-cell code. This approach is based on multiple electron-electron, electron-ion, and ion-ion binary collision and accounts for both the free and the bound electrons in the plasmas. This approach enables one to calculate the stopping of particles in a more natural manner than existing theoretical treatment. In the low-temperature limit, when "all" electrons are bound to the nucleus, the stopping power coincides with the predictions from the Bethe-Bloch formula and is consistent with the data from the National Institute of Standard and Technology database. At higher temperatures, some of the bound electrons are ionized, and this increases the stopping power in the plasmas, as demonstrated by A. B. Zylstra et al. [Phys. Rev. Lett. 114, 215002 (2015)], 10.1103/PhysRevLett.114.215002. At even higher temperatures, the degree of ionization reaches a maximum and thus decreases the stopping power due to the suppression of collision frequency between projected proton beam and hot plasmas in the target.

  8. Approaches to refractory epilepsy

    PubMed Central

    Engel, Jerome

    2014-01-01

    Epilepsy is one of the most common serious neurological conditions, and 30 to 40% of people with epilepsy have seizures that are not controlled by medication. Patients are considered to have refractory epilepsy if disabling seizures continue despite appropriate trials of two antiseizure drugs, either alone or in combination. At this point, patients should be referred to multidisciplinary epilepsy centers that perform specialized diagnostic testing to first determine whether they are, in fact, pharmacoresistant, and then, if so, offer alternative treatments. Apparent pharmacoresistance can result from a variety of situations, including noncompliance, seizures that are not epileptic, misdiagnosis of the seizure type or epilepsy syndrome, inappropriate use of medication, and lifestyle issues. For patients who are pharmacoresistant, surgical treatment offers the best opportunity for complete freedom from seizures. Surgically remediable epilepsy syndromes have been identified, but patients with more complicated epilepsy can also benefit from surgical treatment and require more specialized evaluation, including intracranial EEG monitoring. For patients who are not surgical candidates, or who are unwilling to consider surgery, a variety of other alternative treatments can be considered, including peripheral or central neurostimulation, ketogenic diet, and complementary and alternative approaches. When such alternative treatments are not appropriate or effective, quality of life can still be greatly improved by the psychological and social support services offered by multidisciplinary epilepsy centers. A major obstacle remains the fact that only a small proportion of patients with refractory epilepsy are referred for expert evaluation and treatment. PMID:24791078

  9. Halitosis: the multidisciplinary approach

    PubMed Central

    Bollen, Curd ML; Beikler, Thomas

    2012-01-01

    Halitosis, bad breath or oral malodour are all synonyms for the same pathology. Halitosis has a large social and economic impact. For the majority of patients suffering from bad breath, it causes embarrassment and affects their social communication and life. Moreover, halitosis can be indicative of underlying diseases. Only a limited number of scientific publications were presented in this field until 1995. Ever since, a large amount of research is published, often with lack of evidence. In general, intraoral conditions, like insufficient dental hygiene, periodontitis or tongue coating are considered to be the most important cause (85%) for halitosis. Therefore, dentists and periodontologists are the first-line professionals to be confronted with this problem. They should be well aware of the origin, the detection and especially of the treatment of this pathology. In addition, ear–nose–throat-associated (10%) or gastrointestinal/endocrinological (5%) disorders may contribute to the problem. In the case of halitophobia, psychiatrical or psychological problems may be present. Bad breath needs a multidisciplinary team approach: dentists, periodontologists, specialists in family medicine, ear–nose–throat surgeons, internal medicine and psychiatry need to be updated in this field, which still is surrounded by a large taboo. Multidisciplinary bad breath clinics offer the best environment to examine and treat this pathology that affects around 25% of the whole population. This article describes the origin, detection and treatment of halitosis, regarded from the different etiological origins. PMID:22722640

  10. The Stepping Stone Approach

    NASA Astrophysics Data System (ADS)

    Brumfitt, A.

    Education is a profession in its own right. It has its own parameters, passions and language. Having the responsibility both of educare and educere, education has a focus of delivering specific factual knowledge whilst drawing out the creative mind. Space Science is a special vehicle having the properties of both educare and educere. It has a magic and wonder that touches the very essence of an individual and his place in time and space; it offers the "wow" factor that all teachers strive for. Space Science is the wrapping paper for other elements in the curriculum, e.g. cross-curricula and skill-based activities, such as language development, creativity, etc. as well as the pure sciences which comprise of engineering, physics and other natural sciences from astronomy to chemistry to biology. Each of these spheres of influence are relevant from kindergarten to undergraduate studies and complement, and in addition support informal education in museums, science centers and the world of e-learning. ESA Science Education has devised the "Stepping Stone Approach" to maximize the greatest outreach to all education stakeholders in Europe. In this paper we illustrate how to best reach these target groups with very specific activities to trigger and sustain enthusiasm whilst supporting the pedagogical, subject content and skill-based needs of a prescribed curriculum.

  11. Approach to hypohidrosis.

    PubMed

    Chia, K Y; Tey, H L

    2013-07-01

    Hypohidrosis refers to diminished sweating in response to appropriate stimuli. This can cause hyperthermia, heat exhaustion and death. The aetiology of hypohidrosis can be divided into exogenous, dermatological and neurological causes. Exogenous causes act either by systemic neurohormonal inhibition of sweating or localised damage to the skin and sweat glands. Dermatological disorders can result from congenital disorders, wherein other ectodermal tissues may also be affected, or acquired disorders in which manifestations of the primary disease predominate. Neurological disorders should be classified based on an upper motor neuron or lower motor neuron pattern of disease. In the former, there is spasticity and hyperactive reflexes whereas in the latter, flaccidity and hypoactive reflexes predominate. Acquired idiopathic generalised anhidrois refers to isolated anhidrosis with no other detectable abnormalities. When approaching a patient with hypohidrois, exogenous causes should first be excluded. Physical examination, paying attention to mucocutaneous manifestations and neurological signs, will dichotomise if the lesion is dermatological or neurological. In the former, a skin biopsy is the investigation of choice. In the latter, one should consider magnetic resonance imaging of the brain and spinal cord for upper motor neuron lesions, nerve conduction tests for lower motor neuron lesions and autonomic nerve function tests for autonomic dysfunction. Finally, if a diagnosis of acquired idiopathic generalised anhidrosis is suspected, a quantitative sudomotor axon reflex test and serum immunoglobulin-E levels may be performed. Treatment involves addressing the underlying condition and avoidance of aggravating factors. Acquired idiopathic generalised anhidrosis responds well to high dose systemic corticosteroids.

  12. Endoscopic Endonasal Transsphenoidal Approach

    PubMed Central

    Cappabianca, Paolo; Alfieri, Alessandra; Colao, Annamaria; Ferone, Diego; Lombardi, Gaetano; de Divitiis, Enrico

    1999-01-01

    The outcome of endoscopic endonasal transsphenoidal surgery in 10 patients with pituitary adenomas was compared with that of traditional transnasal transsphenoidal approach (TTA) in 20 subjects. Among the 10 individuals subjected to “pure endoscopy,” 2 had a microadenoma, 1 an intrasellar macroadenoma, 4 had a macroadenoma with suprasellar expansion, 2 had a macroadenoma with supra-parasellar expansion, and 1 a residual tumor; 5 had acromegaly and 5 had a nonfunctioning adenoma (NFA). Among the patients subjected to TTA, 4 had a microadenoma, 2 had an intrasellar macroadenoma, 6 had a macroadenoma with suprasellar expansion, 4 had a macroadenoma with supra-parasellar expansion, and 4 had a residual tumor; 9 patients had acromegaly, 1 hyperprolactinemia, 1 Cushing's disease, and 9 a NFA. At the macroscopic evaluation, tumor removal was total (100%) after endoscopy in 9 patients and after TTA in 14 patients. Six months after surgery, magnetic resonance imaging (MRI) confirmed the total tumor removal in 21 of 23 patients (91.3%). Circulating growth hormone (GH) and insulin-like growth factor-I (IGF-I) significantly decreased 6 months after surgery in all 14 acromegalic patients: normalization of plasma IGF-I levels was obtained in 4 of 5 patients after the endoscopic procedure and in 4 of 9 patients after TTA. Before surgery, pituitary hormone deficiency was present in 14 out of 30 patients: pituitary function improved in 4 patients, remaining unchanged in the other 10 patients. Visual field defects were present before surgery in 4 patients, and improved in all. Early surgical results in the group of 10 patients who underwent endoscopic pituitary tumor removal were at least equivalent to those of standard TTA, with excellent postoperative course. Postsurgical hospital stay was significantly shorter (3.1 ± 0.4 vs. 6.2 ± 0.3 days, p < 0.001) after endoscopy as compared to TTA. ImagesFigure 1Figure 2 PMID:17171126

  13. Skull base approaches in neurosurgery

    PubMed Central

    2010-01-01

    The skull base surgery is one of the most demanding surgeries. There are different structures that can be injured easily, by operating in the skull base. It is very important for the neurosurgeon to choose the right approach in order to reach the lesion without harming the other intact structures. Due to the pioneering work of Cushing, Hirsch, Yasargil, Krause, Dandy and other dedicated neurosurgeons, it is possible to address the tumor and other lesions in the anterior, the mid-line and the posterior cranial base. With the transsphenoidal, the frontolateral, the pterional and the lateral suboccipital approach nearly every region of the skull base is exposable. In the current state many different skull base approaches are described for various neurosurgical diseases during the last 20 years. The selection of an approach may differ from country to country, e.g., in the United States orbitozygomaticotomy for special lesions of the anterior skull base or petrosectomy for clivus meningiomas, are found more frequently than in Europe. The reason for writing the review was the question: Are there keyhole approaches with which someone can deal with a vast variety of lesions in the neurosurgical field? In my opinion the different surgical approaches mentioned above cover almost 95% of all skull base tumors and lesions. In the following text these approaches will be described. These approaches are: 1) pterional approach 2) frontolateral approach 3) transsphenoidal approach 4) suboccipital lateral approach These approaches can be extended and combined with each other. In the following we want to enhance this philosophy. PMID:20602753

  14. The narrative approach to personalisation

    NASA Astrophysics Data System (ADS)

    Conlan, Owen; Staikopoulos, Athanasios; Hampson, Cormac; Lawless, Séamus; O'keeffe, Ian

    2013-06-01

    This article describes the narrative approach to personalisation. This novel approach to the generation of personalised adaptive hypermedia experiences employs runtime reconciliation between a personalisation strategy and a number of contextual models (e.g. user and domain). The approach also advocates the late binding of suitable content and services to the generated personalised pathway resulting in an interactive composition that comprises services as well as content. This article provides a detailed definition of the narrative approach to personalisation and showcases the approach through the examination of two use-cases: the personalised digital educational games developed by the ELEKTRA and 80Days projects; and the personalised learning activities realised as part of the AMAS project. These use-cases highlight the general applicability of the narrative approach and how it has been applied to create a diverse range of real-world systems.

  15. Defining biocultural approaches to conservation.

    PubMed

    Gavin, Michael C; McCarter, Joe; Mead, Aroha; Berkes, Fikret; Stepp, John Richard; Peterson, Debora; Tang, Ruifei

    2015-03-01

    We contend that biocultural approaches to conservation can achieve effective and just conservation outcomes while addressing erosion of both cultural and biological diversity. Here, we propose a set of guidelines for the adoption of biocultural approaches to conservation. First, we draw lessons from work on biocultural diversity and heritage, social-ecological systems theory, integrated conservation and development, co-management, and community-based conservation to define biocultural approaches to conservation. Second, we describe eight principles that characterize such approaches. Third, we discuss reasons for adopting biocultural approaches and challenges. If used well, biocultural approaches to conservation can be a powerful tool for reducing the global loss of both biological and cultural diversity.

  16. Approaching cancer pain relief.

    PubMed

    Lickiss, J N

    2001-01-01

    Pain is defined as an unpleasant experience-it is subjective and achieving pain relief is achieving a change in the patient's experience. There needs to be an adequate concept of a human person (an ecological model will be discussed) and a logical process for approaching pain relief in an individual patient (e.g. the plan used in the Sydney Institute of Palliative Medicine). Communication with the patient is critical to get a grasp of him or her as a person, their environment, personal experience and cultural background. Then encourage him or her to tell the story of the cancer saga as they perceive it, listening carefully for the matters which may have given rise to acute distress (for example, delay in diagnosis) and how they adjusted to this. The individual is conveying a great deal about him or herself as they tell their story. Next the story of the treatment and their experience of it, and then the response of their tumour to it--then the story of their pain: when it began, its characteristics, how it evolved, what factors worsen the pain, what relieves it, etc. This is followed by careful clinical examination to clarify what could be the most likely mechanism(s) responsible for the noxious stimulus. Some investigation (e.g. X-ray) may be justified to assist clarification--but not before making a clinical diagnosis (best guess) and commencing treatment with drugs or other logical measures with some local action--depending on the most probable mechanism. Paracetamol/non-steroidal anti-inflammatory drugs (NSAIDs) etc may be logical. Threshold factors should be attended to--comfort, concern always, or anxiolytic or antidepressant drugs if the patient is pathologically anxious or depressed. The opioid drugs--with morphine still as the gold standard--should be appropriately used. This involves careful calibration of dose (below sedative level) normally with an immediate-release, preparation--and, in the case of morphine, specific counselling concerning 'myths' to

  17. A systematic approach to vertically excited states of ethylene using configuration interaction and coupled cluster techniques.

    PubMed

    Feller, David; Peterson, Kirk A; Davidson, Ernest R

    2014-09-14

    A systematic sequence of configuration interaction and coupled cluster calculations were used to describe selected low-lying singlet and triplet vertically excited states of ethylene with the goal of approaching the all electron, full configuration interaction/complete basis set limit. Included among these is the notoriously difficult, mixed valence/Rydberg (1)B(1u) V state. Techniques included complete active space and iterative natural orbital configuration interaction with large reference spaces which led to variational spaces of 1.8 × 10(9) parameters. Care was taken to avoid unintentionally biasing the results due to the widely recognized sensitivity of the V state to the details of the calculation. The lowest vertical and adiabatic ionization potentials to the (2)B(3u) and (2)B3 states were also determined. In addition, the heat of formation of twisted ethylene (3)A1 was obtained from large basis set coupled cluster theory calculations including corrections for core/valence, scalar relativistic and higher order correlation recovery.

  18. A systematic approach to vertically excited states of ethylene using configuration interaction and coupled cluster techniques

    SciTech Connect

    Feller, David Peterson, Kirk A.; Davidson, Ernest R.

    2014-09-14

    A systematic sequence of configuration interaction and coupled cluster calculations were used to describe selected low-lying singlet and triplet vertically excited states of ethylene with the goal of approaching the all electron, full configuration interaction/complete basis set limit. Included among these is the notoriously difficult, mixed valence/Rydberg {sup 1}B{sub 1u} V state. Techniques included complete active space and iterative natural orbital configuration interaction with large reference spaces which led to variational spaces of 1.8 × 10{sup 9} parameters. Care was taken to avoid unintentionally biasing the results due to the widely recognized sensitivity of the V state to the details of the calculation. The lowest vertical and adiabatic ionization potentials to the {sup 2}B{sub 3u} and {sup 2}B{sub 3} states were also determined. In addition, the heat of formation of twisted ethylene {sup 3}A{sub 1} was obtained from large basis set coupled cluster theory calculations including corrections for core/valence, scalar relativistic and higher order correlation recovery.

  19. Loran-C approach considerations

    NASA Technical Reports Server (NTRS)

    Lilley, Robert W.

    1987-01-01

    The use of Loran-C during approaches to landing is investigated. The Avionics Engineering Center has evaluated such approach applications at Galion, Ohio Municipal Airport and at Mansfield, Ohio Lahm airport. Loran-C data were referenced to ground tracker data to determine that the Loran-C approach path was straight, flyable, and parallel to the runway centerline. The Loran-C operational issues that were investigated are listed.

  20. New Approaches to Final Cooling

    SciTech Connect

    Neuffer, David

    2014-11-10

    A high-energy muon collider scenario require a “final cooling” system that reduces transverse emittances by a factor of ~10 while allowing longitudinal emittance increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of the alternative approach. A more explicit understanding of solenoidal cooling beam dynamics is introduced.

  1. Microbial Burden Approach : New Monitoring Approach for Measuring Microbial Burden

    NASA Technical Reports Server (NTRS)

    Venkateswaran, Kasthuri; Vaishampayan, Parag; Barmatz, Martin

    2013-01-01

    Advantages of new approach for differentiating live cells/ spores from dead cells/spores. Four examples of Salmonella outbreaks leading to costly destruction of dairy products. List of possible collaboration activities between JPL and other industries (for future discussion). Limitations of traditional microbial monitoring approaches. Introduction to new approach for rapid measurement of viable (live) bacterial cells/spores and its areas of application. Detailed example for determining live spores using new approach (similar procedure for determining live cells). JPL has developed a patented approach for measuring amount of live and dead cells/spores. This novel "molecular" method takes less than 5 to 7 hrs. compared to the seven days required using conventional techniques. Conventional "molecular" techniques can not discriminate live cells/spores among dead cells/spores. The JPL-developed novel method eliminates false positive results obtained from conventional "molecular" techniques that lead to unnecessary delay in the processing and to unnecessary destruction of food products.

  2. Exomars Mission Verification Approach

    NASA Astrophysics Data System (ADS)

    Cassi, Carlo; Gilardi, Franco; Bethge, Boris

    According to the long-term cooperation plan established by ESA and NASA in June 2009, the ExoMars project now consists of two missions: A first mission will be launched in 2016 under ESA lead, with the objectives to demonstrate the European capability to safely land a surface package on Mars, to perform Mars Atmosphere investigation, and to provide communi-cation capability for present and future ESA/NASA missions. For this mission ESA provides a spacecraft-composite, made up of an "Entry Descent & Landing Demonstrator Module (EDM)" and a Mars Orbiter Module (OM), NASA provides the Launch Vehicle and the scientific in-struments located on the Orbiter for Mars atmosphere characterisation. A second mission with it launch foreseen in 2018 is lead by NASA, who provides spacecraft and launcher, the EDL system, and a rover. ESA contributes the ExoMars Rover Module (RM) to provide surface mobility. It includes a drill system allowing drilling down to 2 meter, collecting samples and to investigate them for signs of past and present life with exobiological experiments, and to investigate the Mars water/geochemical environment, In this scenario Thales Alenia Space Italia as ESA Prime industrial contractor is in charge of the design, manufacturing, integration and verification of the ESA ExoMars modules, i.e.: the Spacecraft Composite (OM + EDM) for the 2016 mission, the RM for the 2018 mission and the Rover Operations Control Centre, which will be located at Altec-Turin (Italy). The verification process of the above products is quite complex and will include some pecu-liarities with limited or no heritage in Europe. Furthermore the verification approach has to be optimised to allow full verification despite significant schedule and budget constraints. The paper presents the verification philosophy tailored for the ExoMars mission in line with the above considerations, starting from the model philosophy, showing the verification activities flow and the sharing of tests

  3. Project Approach: Teaching. Second Edition.

    ERIC Educational Resources Information Center

    Ho, Rose

    The primary objective of the action research chronicled (in English and Chinese) in this book was to shift the teaching method used by preschool teachers in Hong Kong from a teacher-directed mode by training them to use the Project Approach. The secondary objective was to measure children's achievement while using the Project Approach, focusing on…

  4. Integrated approach for biofouling control.

    PubMed

    Vrouwenvelder, J S; Kruithof, J C; Van Loosdrecht, M C M

    2010-01-01

    Despite extensive research efforts, past and present strategies to control biofouling problems in spiral-wound nanofiltration and reverse osmosis membranes have not been successful under all circumstances. Gaining insight in the biofouling process is a first necessity. Based on recent insights, an overview is given of 12 potential complementary approaches to solve biofouling. Combinations of approaches may be more efficient in biofouling control than a single approach. A single approach must be 100% effective, while in combination each individual approach can be partially effective while the combination is still efficient. An integrated Approach for Biofouling Control (ABC) is proposed, based on three corner stones: (i) equipment design and operation, (ii) biomass growth conditions, and (iii) cleaning agents as a framework to control biofouling. While past and present strategies addressed mainly membranes and microorganisms, i.e. removal or inactivation of biomass, this ABC-approach addresses the total membrane filtration system. It is anticipated that this integral approach will enable a more rational and effective control of biofouling. Although in this stage chemical cleaning and biofouling inhibitor dosage seem unavoidable to control biofouling, it is expected that in future--because of sustainability and costs reasons--membrane systems will be developed without or with minimal need for chemical cleaning and dosing. Three potential scenarios for biofouling control are proposed based on (i) biofouling tolerant spiral wound membrane systems, (ii) capillary membranes, and (iii) phosphate limitation.

  5. Science Focus: The Salters' Approach.

    ERIC Educational Resources Information Center

    Berg, Kevin de

    1995-01-01

    Outlines the Salter's approach to teaching and learning science at the Junior Secondary level by showing how the phenomenon of fire is treated in curriculum materials. Discusses contents of the teachers' guide, student texts, and assessment pack. Gives an evaluation of the usefulness of the approach in the Australian context. (Author/MKR)

  6. Approaches to Teaching Foreign Languages.

    ERIC Educational Resources Information Center

    Hesse, M. G., Ed.

    Works by European and American educators from the Renaissance to the twentieth century are presented. A historical re-evaluation of foreign-language teaching combined with the scientific approach of modern linguistics can provide valuable insights for current teaching and learning approaches. Selections are presented from the writings of the…

  7. [Endoscopic approaches to the orbit].

    PubMed

    Cebula, H; Lahlou, A; De Battista, J C; Debry, C; Froelich, S

    2010-01-01

    During the last decade, the use of endoscopic endonasal approaches to the pituitary has increased considerably. The endoscopic endonasal and transantral approaches offer a minimally invasive alternative to the classic transcranial or transconjunctival approaches to the medial aspect of the orbit. The medial wall of the orbit, the orbital apex, and the optic canal can be exposed through a middle meatal antrostomy, an anterior and posterior ethmoidectomy, and a sphenoidotomy. The inferomedial wall of the orbit can be also perfectly visualized through a sublabial antrostomy or an inferior meatal antrostomy. Several reports have described the use of an endoscopic approach for the resection or the biopsy of lesions located on the medial extraconal aspect of the orbit and orbital apex. However, the resection of intraconal lesions is still limited by inadequate instrumentation. Other indications for the endoscopic approach to the orbit are the decompression of the orbit for Graves' ophthalmopathy and traumatic optic neuropathy. However, the optimal management of traumatic optic neuropathy remains very controversial. Endoscopic endonasal decompression of the optic nerve in case of tumor compression could be a more valid indication in combination with radiation therapy. Finally, the endoscopic transantral treatment of blowout fracture of the floor of the orbit is an interesting option that avoids the eyelid or conjunctive incision of traditional approaches. The collaboration between the neurosurgeon and the ENT surgeon is mandatory and reduces the morbidity of the approach. Progress in instrumentation and optical devices will certainly make this approach promising for intraconal tumor of the orbit.

  8. Systems Approach to Environmental Pollution.

    ERIC Educational Resources Information Center

    Chacko, George K., Ed.

    The objective of a two-day Symposium on Systems Approach to Environmental Pollution of the Operations Research Society of America at the 137th Annual Meeting of the American Association for the Advancement of Science, December 27-28, 1970 in Chicago, Illinois, was not to raise the litany of a systems approach as the answer to all environmental…

  9. Mitochondrial biogenesis: pharmacological approaches.

    PubMed

    Valero, Teresa

    2014-01-01

    Organelle biogenesis is concomitant to organelle inheritance during cell division. It is necessary that organelles double their size and divide to give rise to two identical daughter cells. Mitochondrial biogenesis occurs by growth and division of pre-existing organelles and is temporally coordinated with cell cycle events [1]. However, mitochondrial biogenesis is not only produced in association with cell division. It can be produced in response to an oxidative stimulus, to an increase in the energy requirements of the cells, to exercise training, to electrical stimulation, to hormones, during development, in certain mitochondrial diseases, etc. [2]. Mitochondrial biogenesis is therefore defined as the process via which cells increase their individual mitochondrial mass [3]. Recent discoveries have raised attention to mitochondrial biogenesis as a potential target to treat diseases which up to date do not have an efficient cure. Mitochondria, as the major ROS producer and the major antioxidant producer exert a crucial role within the cell mediating processes such as apoptosis, detoxification, Ca2+ buffering, etc. This pivotal role makes mitochondria a potential target to treat a great variety of diseases. Mitochondrial biogenesis can be pharmacologically manipulated. This issue tries to cover a number of approaches to treat several diseases through triggering mitochondrial biogenesis. It contains recent discoveries in this novel field, focusing on advanced mitochondrial therapies to chronic and degenerative diseases, mitochondrial diseases, lifespan extension, mitohormesis, intracellular signaling, new pharmacological targets and natural therapies. It contributes to the field by covering and gathering the scarcely reported pharmacological approaches in the novel and promising field of mitochondrial biogenesis. There are several diseases that have a mitochondrial origin such as chronic progressive external ophthalmoplegia (CPEO) and the Kearns- Sayre syndrome (KSS

  10. [Stewart's acid-base approach].

    PubMed

    Funk, Georg-Christian

    2007-01-01

    In addition to paCO(2), Stewart's acid base model takes into account the influence of albumin, inorganic phosphate, electrolytes and lactate on acid-base equilibrium. It allows a comprehensive and quantitative analysis of acid-base disorders. Particularly simultaneous and mixed metabolic acid-base disorders, which are common in critically ill patients, can be assessed. Stewart's approach is therefore a valuable tool in addition to the customary acid-base approach based on bicarbonate or base excess. However, some chemical aspects of Stewart's approach remain controversial.

  11. Two-component relativistic density-functional calculations of the dimers of the halogens from bromine through element 117 using effective core potential and all-electron methods.

    PubMed

    Mitin, Alexander V; van Wüllen, Christoph

    2006-02-14

    A two-component quasirelativistic Hamiltonian based on spin-dependent effective core potentials is used to calculate ionization energies and electron affinities of the heavy halogen atom bromine through the superheavy element 117 (eka-astatine) as well as spectroscopic constants of the homonuclear dimers of these atoms. We describe a two-component Hartree-Fock and density-functional program that treats spin-orbit coupling self-consistently within the orbital optimization procedure. A comparison with results from high-order Douglas-Kroll calculations--for the superheavy systems also with zeroth-order regular approximation and four-component Dirac results--demonstrates the validity of the pseudopotential approximation. The density-functional (but not the Hartree-Fock) results show very satisfactory agreement with theoretical coupled cluster as well as experimental data where available, such that the theoretical results can serve as an estimate for the hitherto unknown properties of astatine, element 117, and their dimers.

  12. Asteroid 433 Eros Approaches Earth

    NASA Video Gallery

    Asteroid 433 Eros made a close approach to Earth the morning of January 31st coming within 0.17 AU (15 million miles) of our planet. In this set of images taken that morning, the bright moving dot ...

  13. A Mathematical Approach to Hybridization

    ERIC Educational Resources Information Center

    Matthews, P. S. C.; Thompson, J. J.

    1975-01-01

    Presents an approach to hybridization which exploits the similarities between the algebra of wave functions and vectors. This method will account satisfactorily for the number of orbitals formed when applied to hybrids involving the s and p orbitals. (GS)

  14. A Holistic Approach to Algebra.

    ERIC Educational Resources Information Center

    Barbeau, Edward J.

    1991-01-01

    Described are two examples involving recursive mathematical sequences designed to integrate a holistic approach to learning algebra. These examples promote pattern recognition with algebraic justification, full class participation, and mathematical values that can be transferred to other situations. (MDH)

  15. Four Approaches to Entrepreneurship II.

    ERIC Educational Resources Information Center

    Meyer, Earl C.; Nauta, Tom

    1994-01-01

    Four approaches to teaching advanced entrepreneurship in current use are as follows: (1) advanced options such as franchises and buyouts and international entrepreneurship; (2) preentrepreneurship courses; (3) starting a business; and (4) structured experience. (JOW)

  16. Assessment of Optimal Interrogation Approaches

    DTIC Science & Technology

    2007-05-01

    4 ( 01-03-2006 Final March 2006 - May 2007 Assessment of Optimal Interrogation Approaches H9C101-6-0051... interrogator . Specifically, DACA wanted the researchers to gather information from "expert" interrogators (referred to as "superior" interrogators ...common approaches/techniques that are employed by the majority of interrogators . U U U U 129 David E. Smith (314) 209-9495 ext 701 Prepared for the

  17. Multivariate Bioclimatic Ecosystem Change Approaches

    DTIC Science & Technology

    2015-02-06

    Headquarters, US Army Corps of Engineers Washington, DC 20314-1000 ERDC/CERL TR-15-2 ii Abstract Changes in climatic parameters are important in that they... climatic changes on specific installations. To support this need, the research tested and evaluated the application of six multivariate approach...techniques to predict climatic changes on a specific Army installation, Fort Benning, GA. The six approaches were tested for their ability to identify

  18. Bayesian Approach for Inconsistent Information

    PubMed Central

    Stein, M.; Beer, M.; Kreinovich, V.

    2013-01-01

    In engineering situations, we usually have a large amount of prior knowledge that needs to be taken into account when processing data. Traditionally, the Bayesian approach is used to process data in the presence of prior knowledge. Sometimes, when we apply the traditional Bayesian techniques to engineering data, we get inconsistencies between the data and prior knowledge. These inconsistencies are usually caused by the fact that in the traditional approach, we assume that we know the exact sample values, that the prior distribution is exactly known, etc. In reality, the data is imprecise due to measurement errors, the prior knowledge is only approximately known, etc. So, a natural way to deal with the seemingly inconsistent information is to take this imprecision into account in the Bayesian approach – e.g., by using fuzzy techniques. In this paper, we describe several possible scenarios for fuzzifying the Bayesian approach. Particular attention is paid to the interaction between the estimated imprecise parameters. In this paper, to implement the corresponding fuzzy versions of the Bayesian formulas, we use straightforward computations of the related expression – which makes our computations reasonably time-consuming. Computations in the traditional (non-fuzzy) Bayesian approach are much faster – because they use algorithmically efficient reformulations of the Bayesian formulas. We expect that similar reformulations of the fuzzy Bayesian formulas will also drastically decrease the computation time and thus, enhance the practical use of the proposed methods. PMID:24089579

  19. Laparoscopic approach in gastrointestinal emergencies

    PubMed Central

    Jimenez Rodriguez, Rosa M; Segura-Sampedro, Juan José; Flores-Cortés, Mercedes; López-Bernal, Francisco; Martín, Cristobalina; Diaz, Verónica Pino; Ciuro, Felipe Pareja; Ruiz, Javier Padillo

    2016-01-01

    This review focuses on the laparoscopic approach to gastrointestinal emergencies and its more recent indications. Laparoscopic surgery has a specific place in elective procedures, but that does not apply in emergency situations. In specific emergencies, there is a huge range of indications and different techniques to apply, and not all of them are equally settle. We consider that the most controversial points in minimally invasive procedures are indications in emergency situations due to technical difficulties. Some pathologies, such as oesophageal emergencies, obstruction due to colon cancer, abdominal hernias or incarcerated postsurgical hernias, are nearly always resolved by conventional surgery, that is, an open approach due to limited intraabdominal cavity space or due to the vulnerability of the bowel. These technical problems have been solved in many diseases, such as for perforated peptic ulcer or acute appendectomy for which a laparoscopic approach has become a well-known and globally supported procedure. On the other hand, endoscopic procedures have acquired further indications, relegating surgical solutions to a second place; this happens in cholangitis or pancreatic abscess drainage. This endoluminal approach avoids the need for laparoscopic development in these diseases. Nevertheless, new instruments and new technologies could extend the laparoscopic approach to a broader array of potentials procedures. There remains, however, a long way to go. PMID:26973409

  20. The community-reinforcement approach.

    PubMed

    Miller, W R; Meyers, R J; Hiller-Sturmhöfel, S

    1999-01-01

    The community-reinforcement approach (CRA) is an alcoholism treatment approach that aims to achieve abstinence by eliminating positive reinforcement for drinking and enhancing positive reinforcement for sobriety. CRA integrates several treatment components, including building the client's motivation to quit drinking, helping the client initiate sobriety, analyzing the client's drinking pattern, increasing positive reinforcement, learning new coping behaviors, and involving significant others in the recovery process. These components can be adjusted to the individual client's needs to achieve optimal treatment outcome. In addition, treatment outcome can be influenced by factors such as therapist style and initial treatment intensity. Several studies have provided evidence for CRA's effectiveness in achieving abstinence. Furthermore, CRA has been successfully integrated with a variety of other treatment approaches, such as family therapy and motivational interviewing, and has been tested in the treatment of other drug abuse.

  1. New approaches to antibiotic discovery.

    PubMed

    Kealey, C; Creaven, C A; Murphy, C D; Brady, C B

    2017-03-08

    New antibiotics are urgently required by human medicine as pathogens emerge with developed resistance to almost all antibiotic classes. Pioneering approaches, methodologies and technologies have facilitated a new era in antimicrobial discovery. Innovative culturing techniques such as iChip and co-culturing methods which use 'helper' strains to produce bioactive molecules have had notable success. Exploiting antibiotic resistance to identify antibacterial producers performed in tandem with diagnostic PCR based identification approaches has identified novel candidates. Employing powerful metagenomic mining and metabolomic tools has identified the antibiotic'ome, highlighting new antibiotics from underexplored environments and silent gene clusters enabling researchers to mine for scaffolds with both a novel mechanism of action and also few clinically established resistance determinants. Modern biotechnological approaches are delivering but will require support from government initiatives together with changes in regulation to pave the way for valuable, efficacious, highly targeted, pathogen specific antimicrobial therapies.

  2. Variational Approach to Molecular Kinetics.

    PubMed

    Nüske, Feliks; Keller, Bettina G; Pérez-Hernández, Guillermo; Mey, Antonia S J S; Noé, Frank

    2014-04-08

    The eigenvalues and eigenvectors of the molecular dynamics propagator (or transfer operator) contain the essential information about the molecular thermodynamics and kinetics. This includes the stationary distribution, the metastable states, and state-to-state transition rates. Here, we present a variational approach for computing these dominant eigenvalues and eigenvectors. This approach is analogous to the variational approach used for computing stationary states in quantum mechanics. A corresponding method of linear variation is formulated. It is shown that the matrices needed for the linear variation method are correlation matrices that can be estimated from simple MD simulations for a given basis set. The method proposed here is thus to first define a basis set able to capture the relevant conformational transitions, then compute the respective correlation matrices, and then to compute their dominant eigenvalues and eigenvectors, thus obtaining the key ingredients of the slow kinetics.

  3. Employee Reactions to Merit Pay: Cognitive Approach and Social Approach

    ERIC Educational Resources Information Center

    Wang, Yingchun

    2010-01-01

    The dissertation aims to tackle one of the most pressing questions facing the merit pay system researchers and practitioners: Why do merit pay raises have such a small effect on employees' satisfaction, commitment and job performance? My approach to the study of this question is to develop explanatory frameworks from two perspectives: cognitive…

  4. Systems biology approach to bioremediation

    SciTech Connect

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

    2012-06-01

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

  5. New approaches to crisis intervention.

    PubMed

    Motto, J A

    1979-01-01

    Constant efforts to improve crisis services have led to many innovative programs. Some have proven their feasibility and become established procedures. Others are now in a developing stage and still others represent new approaches. A survey of 50 suicide prevention and crisis services around the world provides evidence of a trend toward a broadening range of services, a more active case-finding approach, greater visibility, increased integration into the community care system, and creative leadership by newer and smaller centers as well as the well-established ones. This is being accomplished without relinquishing the traditional respect for anonymity, ever-present availability, and a nonjudgmental regard for each person's need.

  6. ALTERNATIVE APPROACH TO ESTIMATING CANCER ...

    EPA Pesticide Factsheets

    The alternative approach for estimating cancer potency from inhalation exposure to asbestos seeks to improve the methods developed by USEPA (1986). This efforts seeks to modify the the current approach for estimating cancer potency for lung cancer and mesothelioma to account for the current scientific consensus that cancer risk from asbestos depends both on mineral type and on particle size distribution. In brief, epidemiological exposure-response data for lung cancer and mesothelioma in asbestos workers are combined with estimates of the mineral type(s) and partical size distribution at each exposure location in order to estimate potency factors that are specific to a selected set of mineral type and size

  7. Probabilistic approach to EMP assessment

    SciTech Connect

    Bevensee, R.M.; Cabayan, H.S.; Deadrick, F.J.; Martin, L.C.; Mensing, R.W.

    1980-09-01

    The development of nuclear EMP hardness requirements must account for uncertainties in the environment, in interaction and coupling, and in the susceptibility of subsystems and components. Typical uncertainties of the last two kinds are briefly summarized, and an assessment methodology is outlined, based on a probabilistic approach that encompasses the basic concepts of reliability. It is suggested that statements of survivability be made compatible with system reliability. Validation of the approach taken for simple antenna/circuit systems is performed with experiments and calculations that involve a Transient Electromagnetic Range, numerical antenna modeling, separate device failure data, and a failure analysis computer program.

  8. Multidisciplinary Approaches in Evolutionary Linguistics

    ERIC Educational Resources Information Center

    Gong, Tao; Shuai, Lan; Wu, Yicheng

    2013-01-01

    Studying language evolution has become resurgent in modern scientific research. In this revival field, approaches from a number of disciplines other than linguistics, including (paleo)anthropology and archaeology, animal behaviors, genetics, neuroscience, computer simulation, and psychological experimentation, have been adopted, and a wide scope…

  9. Classical approach in atomic physics

    NASA Astrophysics Data System (ADS)

    Solov'ev, E. A.

    2011-12-01

    The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of a hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom discovered with the help of Poincaré section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treated as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well.

  10. Writing Approaches of Graduate Students

    ERIC Educational Resources Information Center

    Lavelle, Ellen; Bushrow, Kathy

    2007-01-01

    The writing approach framework provides a comprehensive perspective on college-level academic writing based on the relationship of writers' beliefs and strategies to the quality of written outcomes. However, despite increased demands for more and better writing at the graduate level, little is known about graduate-level writing processes or about…

  11. Building America Systems Engineering Approach

    SciTech Connect

    2011-12-15

    The Building America Research Teams use a systems engineering approach to achieve higher quality and energy savings in homes. Using these techniques, the energy consumption of new houses can be reduced by 40% or more with little or no impact on the cost of ownership.

  12. The "Rear View Mirror" Approach.

    ERIC Educational Resources Information Center

    Nord, James R.

    1987-01-01

    The new interactive videodisk systems with augmented audio capabilities have great potential for improving the teaching of foreign languages. At present that potential is unfulfilled because the profession is following a "rear view mirror" approach to media use: first, to fixate current practice; second, to distribute it broadly; and last, to…

  13. Twenty Approaches to Individual Change

    ERIC Educational Resources Information Center

    Ewing, Dorlesa Barmettler

    1977-01-01

    The author reviews traditional helping systems of therapy, i.e., psychonalytic, experiential/phenomenological, cognitive, and behavioral, as well as mind-body systems approaches of transcendental meditation, biofeedback, aerobic exercise training, nutrition, and bioenergetics analysis. Therapists are admonished to learn about these various…

  14. Comparative Psychology: An Epigenetic Approach.

    ERIC Educational Resources Information Center

    Greenberg, Gary

    1987-01-01

    A comparative psychology course oriented around the themes of phylogeny and ontogeny is described. The course emphasizes the evolution and development of behavioral processes and includes a discussion of the concept of integrative levels and Schneirla's approach/withdrawal theory. The course evaluates genetic determinism and stresses the principle…

  15. A Freudian Approach to Education.

    ERIC Educational Resources Information Center

    Gartner, Sandra L.

    This document offers the point of view that Bruno Bettelheim's writings, based on Sigmund Freud's approach to education, suggest the most practical applications for achieving positive results within the classroom. The overall result of a student being taught all through school by the Freudian method would be an extremely positive one. Such a…

  16. Ethnic Studies: Issues and Approaches.

    ERIC Educational Resources Information Center

    Yang, Philip Q.

    This book offers a comprehensive definition of the field of ethnic studies, covering both major issues in the field and its theoretical and methodological approaches. It traces the origins and evolution of the discipline in the United States and maps its domain. Some of the current issues addressed include affirmative action, illegal/legal…

  17. Force approach to radiation reaction

    SciTech Connect

    López, Gustavo V.

    2016-02-15

    The difficulty of the usual approach to deal with the radiation reaction is pointed out, and under the condition that the radiation force must be a function of the external force and is zero whenever the external force be zero, a new and straightforward approach to radiation reaction force and damping is proposed. Starting from the Larmor formula for the power radiated by an accelerated charged particle, written in terms of the applied force instead of the acceleration, an expression for the radiation force is established in general, and applied to the examples for the linear and circular motion of a charged particle. This expression is quadratic in the magnitude of the applied force, inversely proportional to the speed of the charged particle, and directed opposite to the velocity vector. This force approach may contribute to the solution of the very old problem of incorporating the radiation reaction to the motion of the charged particles, and future experiments may tell us whether or not this approach point is in the right direction.

  18. Interdisciplinary Approach to Building Construction.

    ERIC Educational Resources Information Center

    Armstrong, Harry

    The paper discusses the interdisciplinary approach used by the Amity High School House Construction Project to develop a construction cluster in a small high school, to give students on-the-job training, and to teach them the relevancy of academic education. The project's monthly plan of action is briefly described. Suggested activities,…

  19. Early Writing: A Developmental Approach.

    ERIC Educational Resources Information Center

    Goetz, Elizabeth; And Others

    This document consists of four papers on the acquisition of writing skills by young children. The first paper provides a historical and developmental perspective on early writing. Children's development of manual dexterity is briefly overviewed and aspects of the educational approaches of Pestalozzi, Montessori, Chomsky, Rogers and Ashton-Warner…

  20. Approaches to Drug Abuse Counseling.

    ERIC Educational Resources Information Center

    Boren, John J., Ed.; Onken, Lisa Simon, Ed.; Carroll, Kathleen M., Ed.

    The intent of this book is to present information on various counseling approaches for drug abuse used in some of the best known and most respected treatment programs in the United States. In an effort to make the comparison of the various models less difficult and to clarify how the model is applied in practice, each chapter follows a specific…

  1. Technical Training: A Systematic Approach.

    ERIC Educational Resources Information Center

    Gammuto, John J.

    1980-01-01

    To employ scarce personnel and money to best advantage, company management must diagnose critical training needs and assign them priorities. A systems approach is recommended, which gives focus to training design while accommodating most organization training goals. Included are suggestions for system design, facility management, and cost…

  2. Using Natural Approach Teaching Techniques.

    ERIC Educational Resources Information Center

    Whitman, Charles

    1986-01-01

    Describes a beginning foreign language class applying the principles of Stephen Krashen's "Natural Approach" and James Asher's "Total Physical Response" method. Initially students carry out the instructor's commands in the form of actions rather than being required to speak. In later stages role play and simple discussions are…

  3. Indian Education: An Intergenerational Approach.

    ERIC Educational Resources Information Center

    Buffalohead, Priscilla; Sterner, Michele

    The Indian Education Program in the Osseo School District (Minnesota) serves approximately 200 American Indian students in grades K-12 from 27 schools and a variety of tribes. The Program's intergenerational approach reflects tribal traditions in that generations learn together and grandparents, parents, and students are involved in the…

  4. Map Projections: Approaches and Themes

    ERIC Educational Resources Information Center

    Steward, H. J.

    1970-01-01

    Map projections take on new meaning with location systems needed for satellites, other planets and space. A classroom approach deals first with the relationship between the earth and the globe, then with transformations to flat maps. Problems of preserving geometric qualities: distance, angles, directions are dealt with in some detail as are…

  5. Force approach to radiation reaction

    NASA Astrophysics Data System (ADS)

    López, Gustavo V.

    2016-02-01

    The difficulty of the usual approach to deal with the radiation reaction is pointed out, and under the condition that the radiation force must be a function of the external force and is zero whenever the external force be zero, a new and straightforward approach to radiation reaction force and damping is proposed. Starting from the Larmor formula for the power radiated by an accelerated charged particle, written in terms of the applied force instead of the acceleration, an expression for the radiation force is established in general, and applied to the examples for the linear and circular motion of a charged particle. This expression is quadratic in the magnitude of the applied force, inversely proportional to the speed of the charged particle, and directed opposite to the velocity vector. This force approach may contribute to the solution of the very old problem of incorporating the radiation reaction to the motion of the charged particles, and future experiments may tell us whether or not this approach point is in the right direction.

  6. A Psychoanalytic Approach to Fieldwork

    ERIC Educational Resources Information Center

    Ramvi, Ellen

    2012-01-01

    This article focuses on what both psychoanalysis and anthropology have in common: the emphasis on the researcher's own experience. An ethnographic fieldwork will be used to illustrate how a psychoanalytical approach unfolds the material when studying conditions for learning from experience among teachers in two Norwegian junior high schools, and…

  7. The Labelling Approach to Deviance.

    ERIC Educational Resources Information Center

    Rains, Prudence M.; Kitsuse, John L.; Duster, Troy; Freidson, Eliot

    2003-01-01

    This reprint of one chapter from the 1975 text, "Issues in the Classification of Children" by Nicholas Hobbs and others, addresses the theoretical, methodological, and empirical issues involved in the "labeling" approach to the sociology of deviance. It examines the social process of classification, the use of classification in social agencies,…

  8. Partnership in Sector Wide Approaches

    ERIC Educational Resources Information Center

    Tolley, Hilary

    2011-01-01

    Within the context of bilateral support to the education sector in Tonga and the Solomon Islands, this paper will explore how the discourse of "partnership" has been interpreted and activated within the Sector wide approach (SWAp). In concentrating particularly on the relationship between the respective Ministries of Education and New…

  9. Building Biographies: A Snapshot Approach.

    ERIC Educational Resources Information Center

    Zarnowski, Myra

    1986-01-01

    Proposes a method for building biographies with elementary students. Called the "snapshot approach," it encourages students to visualize memorable events in the life of the person being studied. Step one is gathering and studying biographical information, step two is selecting the material to use, and step three is arranging and interpreting the…

  10. Chemical Calculations; An Audiotutorial Approach.

    ERIC Educational Resources Information Center

    Lower, Stephen K.

    An audiotutorial approach to problem-solving in college chemistry relying upon audio tapes is available. The program is designed to increase the teacher's effectiveness by providing individualized attention to student difficulties related to problem-solving. Problem solutions are recorded on audio tapes (designed for use with Sony TC-160 cassettes…

  11. Organ donation: a communitarian approach.

    PubMed

    Etzioni, Amitai

    2003-03-01

    Recently, various suggestions have been made to respond to the increasingly great shortage of organs by paying for them. Because of the undesirable side effects of such approaches (commodification, injustice, and costs), a communitarian approach should be tried first. A communitarian approach to the problem of organ shortage entails changing the moral culture so that members of society will recognize that donating one's organs, once they are no longer of use to the donor, is the moral (right) thing to do. This approach requires much greater and deeper efforts than sharing information and making public service announcements. It entails a moral dialogue, in which the public is engaged, leading to a change in what people expect from one another. Among the devices that could help change the moral culture are a public statement, endorsed by community members and leaders, that expresses the community sense that donation "is what a good person does" and a community-specific web page that lists those who have made the commitment. A change in law so that a person's wishes in the matter are recognized as final and binding are also desired. This position paper deals only with cadaver organs and not living donors.

  12. Budgeting Approaches in Community Colleges

    ERIC Educational Resources Information Center

    Palmer, James C.

    2014-01-01

    Several budgeting approaches have been initiated as alternatives to the traditional, incremental process. These include formula budgeting; zero-base budgeting; planning, programming, and budgeting systems; and responsibility center budgeting. Each is premised on assumptions about how organizations might best make resource allocation decisions.…

  13. Three Approaches to Evaluation Research.

    ERIC Educational Resources Information Center

    Rafter, David O.

    1984-01-01

    Three common evaluation models are the scientific, interactive, and hybrid. A study of evaluation projects mandated by the Wisconsin legislature revealed that the hybrid model was most effective in achieving policy planning and policy control utilization, the interactive approach provided aid to individual utilization, and the scientific approach…

  14. Cleft Palate; A Multidiscipline Approach.

    ERIC Educational Resources Information Center

    Stark, Richard B., Ed.

    Nineteen articles present a multidisciplinary approach to the management of facial clefts. The following subjects are discussed: the history of cleft lip and cleft palate surgery; cogenital defects; classification; the operation of a cleft palate clinic; physical examination of newborns with cleft lip and/or palate; nursing care; anesthesia;…

  15. Profile Analysis: Multidimensional Scaling Approach.

    ERIC Educational Resources Information Center

    Ding, Cody S.

    2001-01-01

    Outlines an exploratory multidimensional scaling-based approach to profile analysis called Profile Analysis via Multidimensional Scaling (PAMS) (M. Davison, 1994). The PAMS model has the advantages of being applied to samples of any size easily, classifying persons on a continuum, and using person profile index for further hypothesis studies, but…

  16. Teaching Ethics: A Direct Approach.

    ERIC Educational Resources Information Center

    Penn, William Y., Jr.

    1990-01-01

    Compares five designs of an undergraduate ethics course at Saint Edward's University (Texas) in a 5-year study involving 318 students. Reveals the effectiveness of directly targeting and teaching in tandem the elements of moral reasoning. Bases study on Lawrence Kohlberg's moral development theory. Argues that this approach best develops moral…

  17. Guitar Class: A Multifaceted Approach.

    ERIC Educational Resources Information Center

    Bartel, Lee R.

    1990-01-01

    Suggests that the bias linking guitars to popular culture has needlessly limited approaches to teaching guitar. Examines how each of five current programs develops different music skills. Advocates a comprehensive, multifaceted program capable of emphasizing student skills in melody, harmony, perception, creativity, and performance over six years…

  18. Family Research: An Ethnographic Approach

    PubMed Central

    Stein, Howard F.

    1991-01-01

    An ethnographic approach based on in-depth interviewing, naturalistic and participant observation, narrative description, and contextual interpretation is proposed as a tool for family health care research. The multiple meanings of family, both for research clinicians and for society, are considered. The problem of how a family orientation is incorporated into biomedical' health care is discussed. PMID:21229058

  19. ENGLISH WRITING, APPROACHES TO COMPOSITION.

    ERIC Educational Resources Information Center

    Euclid English Demonstration Center, OH.

    THIS COLLECTION OF PAPERS BY STAFF MEMBERS OF THE EUCLID ENGLISH DEMONSTRATION CENTER FOCUSES ON APPROACHES TO THE TEACHING OF COMPOSITION IN THE JUNIOR HIGH SCHOOL. THE PAPERS ARE (1) "LITERATURE AND COMPOSITION," BY JAMES F. MCCAMPBELL, (2) "COMPOSING--EPIPHANY AND DETAIL," BY JOSEPH DYESS, (3) "THE LANGUAGE COMPOSITION…

  20. Early Intervention Approaches. Chapter 9.

    ERIC Educational Resources Information Center

    1996

    This collection of papers presented at a 1996 conference on children's mental health focuses on early intervention approaches. Papers have the following titles and authors: (1) "Child Maltreatment and Prenatal Exposure to Alcohol and Other Drugs: Some Preliminary Findings" (Patrick A. Curtis and Mary Wood Schneider); (2) "Evaluation…

  1. Approaches to Rural Professional Development

    ERIC Educational Resources Information Center

    Thornburg, Kathy R.; Scott, Jacqueline L.

    2006-01-01

    Three professional development approaches have shown promise in raising the competency level of early childhood professionals in rural areas. Provider registry systems gather information that provides a foundation for further professional development initiatives and systemic development. Statewide professional development systems designed to serve…

  2. New Approaches to Comparative Education.

    ERIC Educational Resources Information Center

    Altbach, Philip G., Ed.; Kelly, Gail P., Ed.

    Perspectives on research in comparative education are presented in 17 articles originally published in the "Comparative Education Review." The objective is to present an array of new viewpoints, orientations, and approaches. Titles and authors are: "Introduction: Perspectives on Comparative Education" (Philip G. Altbach, Gail P. Kelly); "Critical…

  3. Approaches to Academic Growth Assessment

    ERIC Educational Resources Information Center

    Anderman, Eric M.; Gimbert, Belinda; O'Connell, Ann A.; Riegel, Lisa

    2015-01-01

    Background: There is much interest in assessing growth in student learning. Assessments of growth have important implications and affect many policy decisions at many levels. Aims: In the present article, we review some of the different approaches to measuring growth and examine the implications of their usage. Sample: Samples used in research on…

  4. Alternative Approaches to Introductory Economics.

    ERIC Educational Resources Information Center

    Bonello, Frank J.; And Others

    This document examines the educational output of three alternative approaches to introductory macroeconomics at the University of Notre Dame. The framework for evaluation consists of the cognitive and affective tradeoffs entailed by using a new experimental course as opposed to two more traditional courses. The experimental course is a freshman…

  5. Pluralistic Approaches to Art Criticism.

    ERIC Educational Resources Information Center

    Blandy, Doug, Ed.; Congdon, Kristin G., Ed.

    Contributors to this anthology analyze the contemporary academic methods for critiquing art and suggest new ways that might further the understandings of art created by diverse individuals and groups. Essays are organized into three sections. Part 1, "Changes and Extensions in Critical Approaches" includes essays: (1) "Beyond Universalism in Art…

  6. Approaching Bose-Einstein Condensation

    ERIC Educational Resources Information Center

    Ferrari, Loris

    2011-01-01

    Bose-Einstein condensation (BEC) is discussed at the level of an advanced course of statistical thermodynamics, clarifying some formal and physical aspects that are usually not covered by the standard pedagogical literature. The non-conventional approach adopted starts by showing that the continuum limit, in certain cases, cancels out the crucial…

  7. Toxicological approaches to complex mixtures.

    PubMed Central

    Mauderly, J L

    1993-01-01

    This paper reviews the role of toxicological studies in understanding the health effects of environmental exposures to mixtures. The approach taken is to review mixtures that have received the greatest emphasis from toxicology; major mixtures research programs; the toxicologist's view of mixtures and approaches to their study; and the complementary roles of toxicological, clinical, and epidemiological studies. Studies of tobacco smoke, engine exhaust, combustion products, and air pollutants comprise most of the past research on mixtures. Because of their great experimental control over subjects, exposures, and endpoints, toxicologists tend to consider a wider range of toxic interactions among mixture components and sequential exposures than is practical for human studies. The three fundamental experimental approaches used by toxicologists are integrative (studying the mixture as a whole), dissective (dissecting a mixture to determine causative constituents), and synthetic (studying interactions between agents in simple combinations). Toxicology provides information on potential hazards, mechanisms by which mixture constituents interact to cause effects, and exposure dose-effect relationships; but extrapolation from laboratory data to quantitative human health risks is problematic. Toxicological, clinical, and epidemiological approaches are complementary but are seldom coordinated. Fostering synergistic interactions among the disciplines in studying the risks from mixtures could be advantageous. PMID:7515806

  8. Intervention Strategies: A Multicultural Approach.

    ERIC Educational Resources Information Center

    Cheng, Li-Rong Lilly

    1989-01-01

    Intervention planning for limited-English-proficient students calls for an experiential approach which compares and contrasts the students' home culture with mainstream United States culture. Methods are presented for incorporating student culture in intervention activities (building a multicultural calendar, studying folk tales) and for…

  9. Minimalist Approach to Perceptual Interactions

    PubMed Central

    Lenay, Charles; Stewart, John

    2012-01-01

    Work aimed at studying social cognition in an interactionist perspective often encounters substantial theoretical and methodological difficulties: identifying the significant behavioral variables; recording them without disturbing the interaction; and distinguishing between: (a) the necessary and sufficient contributions of each individual partner for a collective dynamics to emerge; (b) features which derive from this collective dynamics and escape from the control of the individual partners; and (c) the phenomena arising from this collective dynamics which are subsequently appropriated and used by the partners. We propose a minimalist experimental paradigm as a basis for this conceptual discussion: by reducing the sensory inputs to a strict minimum, we force a spatial and temporal deployment of the perceptual activities, which makes it possible to obtain a complete recording and control of the dynamics of interaction. After presenting the principles of this minimalist approach to perception, we describe a series of experiments on two major questions in social cognition: recognizing the presence of another intentional subject; and phenomena of imitation. In both cases, we propose explanatory schema which render an interactionist approach to social cognition clear and explicit. Starting from our earlier work on perceptual crossing we present a new experiment on the mechanisms of reciprocal recognition of the perceptual intentionality of the other subject: the emergent collective dynamics of the perceptual crossing can be appropriated by each subject. We then present an experimental study of opaque imitation (when the subjects cannot see what they themselves are doing). This study makes it possible to characterize what a properly interactionist approach to imitation might be. In conclusion, we draw on these results, to show how an interactionist approach can contribute to a fully social approach to social cognition. PMID:22582041

  10. CONCEPTS AND APPROACHES FOR THE ...

    EPA Pesticide Factsheets

    This document is intended to assist users in establishing or refining protocols, including the specific methods related to field sampling, laboratory sample processing, taxonomy, data entry, management and analysis, and final assessment and reporting. It also reviews and provides information on development of monitoring designs to address certain types of environmental questions and approaches for documenting and reporting data quality and performance characteristics for large river biological monitoring. The approaches presented are not intended to replace existing program components but may in some cases be useful for refining them. The goal of this research is to develop methods and indicators that are useful for evaluating the condition of aquatic communities, for assessing the restoration of aquatic communities in response to mitigation and best management practices, and for determining the exposure of aquatic communities to different classes of stressors (i.e., pesticides, sedimentation, habitat alteration).

  11. Malaysia implements the integrated approach.

    PubMed

    1977-01-01

    Malaysia has implemented an integrated approach in providing family planning services to eligible couples. In 1964 the government of Malaysia adopted a national family planning program, and implementation began in the urban areas and extended into the rural areas. Other agencies are involved in providing family planning services and information including the Federation of Family Planning Associations, the Ministry of Health, the National Family Planning Board, and the Federal Land Development Authority. The number of women practicing contraception has increased from 20,726 in 1967 to 533,646 by 1976. and other methods, 3.9%, respectively. There has been an increase in the percentage of acceptors between ages 15-29 from 56% in 1968 to 71.3% in 1975. The 2nd Malaysian national plan will use a multidisciplinary approach to the problem.

  12. Intelligent Control Approaches for UAVs

    NASA Technical Reports Server (NTRS)

    KrisnaKumar, Kalmanje

    2003-01-01

    This talk will present overviews of various intelligent control technologies currently being developed and studied at the NASA Ames Research Center as applicable to Unmanned Aerial Vehicles (UAVs), Mars flyers, and to the next generation of flight controllers for manned aircraft. The approaches being examined include: (a) direct adaptive dynamic inverse controller, (b) adaptive critic-based optimal trajectory generator; (c) optimal allocation technique based on linear programming; (4) immunized maneuvering using autopilot building blocks. These approaches can utilize, but do not require, fault detection and isolation information. Piloted and unmanned simulation studies are performed to examine if the intelligent flight control techniques adequately: 1) match flying qualities of modem fly-by-wire flight controllers under nominal conditions; 2) improve performance under failure conditions when sufficient control authority is available; and 3) achieve intelligent maneuvering capabilities for unmanned vehicles. Results obtained so far will be presented and discussed.

  13. Approaches to neuroscience data integration

    PubMed Central

    Lim, Ernest; Samwald, Matthias; Chen, Huajun; Marenco, Luis; Holford, Matthew E.; Morse, Thomas M.; Mutalik, Pradeep; Shepherd, Gordon M.; Miller, Perry L.

    2009-01-01

    As the number of neuroscience databases increases, the need for neuroscience data integration grows. This paper reviews and compares several approaches, including the Neuroscience Database Gateway (NDG), Neuroscience Information Framework (NIF) and Entrez Neuron, which enable neuroscience database annotation and integration. These approaches cover a range of activities spanning from registry, discovery and integration of a wide variety of neuroscience data sources. They also provide different user interfaces for browsing, querying and displaying query results. In Entrez Neuron, for example, four different facets or tree views (neuron, neuronal property, gene and drug) are used to hierarchically organize concepts that can be used for querying a collection of ontologies. The facets are also used to define the structure of the query results. PMID:19505888

  14. Direct Approach to Quantum Tunneling

    NASA Astrophysics Data System (ADS)

    Andreassen, Anders; Farhi, David; Frost, William; Schwartz, Matthew D.

    2016-12-01

    The decay rates of quasistable states in quantum field theories are usually calculated using instanton methods. Standard derivations of these methods rely in a crucial way upon deformations and analytic continuations of the physical potential and on the saddle-point approximation. While the resulting procedure can be checked against other semiclassical approaches in some one-dimensional cases, it is challenging to trace the role of the relevant physical scales, and any intuitive handle on the precision of the approximations involved is at best obscure. In this Letter, we use a physical definition of the tunneling probability to derive a formula for the decay rate in both quantum mechanics and quantum field theory directly from the Minkowski path integral, without reference to unphysical deformations of the potential. There are numerous benefits to this approach, from nonperturbative applications to precision calculations and aesthetic simplicity.

  15. An Approach to Speaker Identification.

    PubMed

    Hollien, Harry

    2016-03-01

    This presentation will provide standards upon which any attempts to meet the challenge of identifying speakers by voice should be based. It is organized into a model based on (i) application of a rigorous research program validating the system, (ii) an upgrading of the organization of the SI area, and (iii) exploitation of new technology. The second part of the presentation will describe an illustrative speech/voice approach to SI development. This effort is also based on an extensive corpus of research. It is suggested that application of the cited standards, plus the illustrative model, will permit reasonable progress to be made. Finally, a number of procedural recommendations are made; they should enhance the efficacy of the proposed approach.

  16. Different approaches of spectral analysis

    NASA Technical Reports Server (NTRS)

    Lacoume, J. L.

    1977-01-01

    Several approaches to the problem of the calculation of spectral power density of a random function from an estimate of the autocorrelation function were studied. A comparative study was presented of these different methods. The principles on which they are based and the hypothesis implied were pointed out. Some indications on the optimization of the length of the estimated correlation function was given. An example of application of the different methods discussed in this paper was included.

  17. Jellyfish Stings: A Practical Approach.

    PubMed

    Lakkis, Najla A; Maalouf, Grace J; Mahmassani, Dina M

    2015-09-01

    Jellyfish have a worldwide distribution. Their stings can cause different reactions, ranging from cutaneous, localized, and self-limited to serious systemic or fatal ones, depending on the envenoming species. Several first aid treatments are used to manage such stings but few have evidence behind their use. This review of the literature describes and discusses the different related first aid and treatment recommendations, ending with a summarized practical approach. Further randomized controlled trials in this field are needed.

  18. [Causal analysis approaches in epidemiology].

    PubMed

    Dumas, O; Siroux, V; Le Moual, N; Varraso, R

    2014-02-01

    Epidemiological research is mostly based on observational studies. Whether such studies can provide evidence of causation remains discussed. Several causal analysis methods have been developed in epidemiology. This paper aims at presenting an overview of these methods: graphical models, path analysis and its extensions, and models based on the counterfactual approach, with a special emphasis on marginal structural models. Graphical approaches have been developed to allow synthetic representations of supposed causal relationships in a given problem. They serve as qualitative support in the study of causal relationships. The sufficient-component cause model has been developed to deal with the issue of multicausality raised by the emergence of chronic multifactorial diseases. Directed acyclic graphs are mostly used as a visual tool to identify possible confounding sources in a study. Structural equations models, the main extension of path analysis, combine a system of equations and a path diagram, representing a set of possible causal relationships. They allow quantifying direct and indirect effects in a general model in which several relationships can be tested simultaneously. Dynamic path analysis further takes into account the role of time. The counterfactual approach defines causality by comparing the observed event and the counterfactual event (the event that would have been observed if, contrary to the fact, the subject had received a different exposure than the one he actually received). This theoretical approach has shown limits of traditional methods to address some causality questions. In particular, in longitudinal studies, when there is time-varying confounding, classical methods (regressions) may be biased. Marginal structural models have been developed to address this issue. In conclusion, "causal models", though they were developed partly independently, are based on equivalent logical foundations. A crucial step in the application of these models is the

  19. A Viable Systems Engineering Approach

    DTIC Science & Technology

    2010-04-01

    methodology was not meeting the needs of the sponsors • The Agile approach Scrum was selected as the only viable solution for managing project...Self-organized teams Slide 11 Source: Agile Alliance (http://www.agilealliance.org/) Scrum Applied to Systems Engineering • Scrum is a framework for...ceremonies • A Scrum project is a series of iterations or Sprints where every 2-4 weeks produces fully developed requirements, functional analyses, and

  20. Rapid Propellant Loading Approach Exploration

    DTIC Science & Technology

    2010-11-01

    was selected. Model-based reasoning ( MBR ) is an innovative way of determining the dynamic state of a process by examining all available sensors...instead of just one or a few. MBR also has the capability to determine the health of the system and predict degradations. Two NASA-developed MBR ...incorporate cryogenic technical and operations knowledge allowing nearly autonomous system operation with minimal supervision. The MBR approach provided

  1. [Behavioral approach to sexual dysfunctions].

    PubMed

    Gellman, C

    1983-01-01

    The basic principles of those behaviourist approaches are: - Treatment of the couple, no matter which partner is apparently "responsible" for the sexual problem, and mutual involvement of both partners. - Sexual information and education regarding the cycle of sexual response, anatomy, biology, and sexual techniques. - Changing negative attitudes vis-à-vis sexuality. - Elimination of sexual anxieties. - Improvement of verbal and corporal communication within the couple. - Learning to know oneself and others better--Initiation to psychological attention and observation.

  2. An efficient iris segmentation approach

    NASA Astrophysics Data System (ADS)

    Gomai, Abdu; El-Zaart, A.; Mathkour, H.

    2011-10-01

    Iris recognition system became a reliable system for authentication and verification tasks. It consists of five stages: image acquisition, iris segmentation, iris normalization, feature encoding, and feature matching. Iris segmentation stage is one of the most important stages. It plays an essential role to locate the iris efficiently and accurately. In this paper, we present a new approach for iris segmentation using image processing technique. This approach is composed of four main parts. (1) Eliminating reflections of light on the eye image based on inverting the color of the grayscale image, filling holes in the intensity image, and inverting the color of the intensity image to get the original grayscale image without any reflections. (2) Pupil boundary detection based on dividing an eye image to nine sub-images and finding the minimum value of the mean intensity for each sub-image to get a suitable threshold value of pupil. (3) Enhancing the contrast of outer iris boundary using exponential operator to have sharp variation. (4) Outer iris boundary localization based on applying a gray threshold and morphological operations on the rectangular part of an eye image including the pupil and the outer boundaries of iris to find the small radius of outer iris boundary from the center of pupil. The proposed approach has been tested on CASIA v1.0 iris image database and other collected iris image database. The experimental results show that the approach is able to detect pupil and outer iris boundary with high accuracy results approximately 100% and reduce time consuming.

  3. Practical approaches in accident analysis

    NASA Astrophysics Data System (ADS)

    Stock, M.

    An accident analysis technique based on successive application of structural response, explosion dynamics, gas cloud formation, and plant operation failure mode models is proposed. The method takes into account the nonideal explosion characteristic of a deflagration in the unconfined cloud. The resulting pressure wave differs significantly from a shock wave and the response of structures like lamp posts and walls can differ correspondingly. This gives a more realistic insight into explosion courses than a simple TNT-equivalent approach.

  4. Hydraulic Modeling of Lock Approaches

    DTIC Science & Technology

    2016-08-01

    cation was that the guidewall design changed from a solid wall to one on pilings in which water was allowed to flow through and/or under the wall ...develops innovative solutions in civil and military engineering, geospatial sciences, water resources, and environmental sciences for the Army, the...magnitudes and directions at lock approaches for open river conditions. The meshes were developed using the Surface- water Modeling System. The two

  5. An Epidemiological Approach to Terrorism

    DTIC Science & Technology

    2006-03-01

    extraordinarily good results for many marketers, and 7 illustrates the benefits of considering ideas to be contagious like viruses or other infectious...and the spread of viruses , we will be better able to understand what it is about the terrorist mentality that infects the susceptible population... virus would), permission marketing (Godin, 1999) and other such approaches to marketing. In a world that is oversaturated with advertisements, the notion

  6. Adaptive approaches to biosecurity governance.

    PubMed

    Cook, David C; Liu, Shuang; Murphy, Brendan; Lonsdale, W Mark

    2010-09-01

    This article discusses institutional changes that may facilitate an adaptive approach to biosecurity risk management where governance is viewed as a multidisciplinary, interactive experiment acknowledging uncertainty. Using the principles of adaptive governance, evolved from institutional theory, we explore how the concepts of lateral information flows, incentive alignment, and policy experimentation might shape Australia's invasive species defense mechanisms. We suggest design principles for biosecurity policies emphasizing overlapping complementary response capabilities and the sharing of invasive species risks via a polycentric system of governance.

  7. Recommended approach to sofware development

    NASA Technical Reports Server (NTRS)

    Mcgarry, F. E.; Page, J.; Eslinger, S.; Church, V.; Merwarth, P.

    1983-01-01

    A set of guideline for an organized, disciplined approach to software development, based on data collected and studied for 46 flight dynamics software development projects. Methods and practices for each phase of a software development life cycle that starts with requirements analysis and ends with acceptance testing are described; maintenance and operation is not addressed. For each defined life cycle phase, guidelines for the development process and its management, and the products produced and their reviews are presented.

  8. On Approach: Jupiter and Io

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of On Approach: Jupiter and Io

    This sequence of images was taken on Jan. 8, 2007, with the New Horizons Long Range Reconnaissance Imager (LORRI), while the spacecraft was about 81 million kilometers (about 50 million miles) from Jupiter. Jupiter's volcanic moon Io is to the right; the planet's Great Red Spot is also visible. The image was one of 11 taken during the Jan. 8 approach sequence, which signaled the opening of the New Horizons Jupiter encounter.

    Even in these early approach images, Jupiter shows different face than what previous visiting spacecraft -- such as Voyager 1, Galileo and Cassini -- have seen. Regions around the equator and in the southern tropical latitudes seem remarkably calm, even in the typically turbulent 'wake' behind the Great Red Spot.

    The New Horizons science team will scrutinize these major meteorological features -- including the unexpectedly calm regions -- to understand the diverse variety of dynamical processes on the solar system's largest planet. These include the newly formed Little Red Spot, the Great Red Spot and a variety of zonal features.

  9. New approaches in GMO detection.

    PubMed

    Querci, Maddalena; Van den Bulcke, Marc; Zel, Jana; Van den Eede, Guy; Broll, Hermann

    2010-03-01

    The steady rate of development and diffusion of genetically modified plants and their increasing diversification of characteristics, genes and genetic control elements poses a challenge in analysis of genetically modified organisms (GMOs). It is expected that in the near future the picture will be even more complex. Traditional approaches, mostly based on the sequential detection of one target at a time, or on a limited multiplexing, allowing only a few targets to be analysed at once, no longer meet the testing requirements. Along with new analytical technologies, new approaches for the detection of GMOs authorized for commercial purposes in various countries have been developed that rely on (1) a smart and accurate strategy for target selection, (2) the use of high-throughput systems or platforms for the detection of multiple targets and (3) algorithms that allow the conversion of analytical results into an indication of the presence of individual GMOs potentially present in an unknown sample. This paper reviews the latest progress made in GMO analysis, taking examples from the most recently developed strategies and tools, and addresses some of the critical aspects related to these approaches.

  10. Molecular Approaches to Sarcoma Therapy

    PubMed Central

    Olsen, R. J.; Tarantolo, S. R.

    2002-01-01

    Soft tissue sarcomas comprise a heterogeneous group of aggressive tumors that have a relatively poor prognosis. Although conventional therapeutic regimens can effectively cytoreduce the overall tumor mass, they fail to consistently achieve a curative outcome. Alternative gene-based approaches that counteract the underlying neoplastic process by eliminating the clonal aberrations that potentiate malignant behavior have been proposed. As compared to the accumulation of gene alterations associated with epithelial carcinomas, sarcomas are frequently characterized by the unique presence of a single chromosomal translocation in each histological subtype. Similar to the Philadelphia chromosome associated with CML, these clonal abnormalities result in the fusion of two independent unrelated genes to generate a unique chimeric protein that displays aberrant activity believed to initiate cellular transformation. Secondary gene mutations may provide an additional growth advantage that further contributes to malignant progression. The recent clinical success of the tyrosine kinase inhibitor, STI571, suggests that therapeutic approaches specifically directed against essential survival factors in sarcoma cells may be effective. This review summarizes published approaches targeting a specific molecular mechanism associated with sarcomagenesis. The strategy and significance of published translational studies in six distinct areas are presented. These include: (1) the disruption of chimeric transcription factor activity; (2) inhibition of growth stimulatory post-translational modifications; (3) restoration of tumor suppressor function; (4) interference with angiogenesis; (5) induction of apoptotic pathways; and (6) introduction of toxic gene products. The potential for improving outcomes in sarcoma patients and the conceptual obstacles to be overcome are discussed. PMID:18521343

  11. Novel therapeutic approaches for haemophilia.

    PubMed

    Shetty, S; Ghosh, K

    2015-03-01

    The major therapy for haemophilia is plasma derived or recombinant clotting factors which are evolving steadily to increase potency, stability and half-life. Research in the area of haemophilia therapeutics, however, is not restricted only to modifications in the recombinant products, but alternate therapeutic strategies are being developed which are in different phases of experimental and clinical trials. This chapter reviews the diverse molecular innovations which are being developed for alternate therapeutic approaches in haemophilia. The data is mainly extracted from the literature and the Conference abstracts. Some of the novel therapeutic approaches include inhibition of anticoagulant pathway factors (activated protein C, antithrombin, tissue factor pathway inhibitor) by monoclonal antibodies, peptide inhibitors, DNA or RNA aptamers, use of variant coagulation factors (factor Xa, factor Va) which are more resistant to inactivation or enzymatically more active and antibody-mediated therapy including a humanized anti-factor IXa/X bispecific antibody mimicking factor VIII. Other approaches include nonsense mutation suppression, induction of prothrombotic microparticles by P-selectin-immunoglobulin chimeras, suppression of fibrinolytic potential either by antifibrinolytics or by the use of mutant molecules of fibrinolytic inhibitors. Few products are proposed as 'stand alone' treatment for haemophilia, while a few can be used as adjuvant therapies to recombinant factors with an aim to reduce the amount of factor intake. All efforts are underway to produce an alternate, novel drug for haemophilia which will have an increased half-life, subcutaneously injectable, non-immunogenic and effective both in the presence and absence of inhibitors.

  12. An abstract approach to music.

    SciTech Connect

    Kaper, H. G.; Tipei, S.

    1999-04-19

    In this article we have outlined a formal framework for an abstract approach to music and music composition. The model is formulated in terms of objects that have attributes, obey relationships, and are subject to certain well-defined operations. The motivation for this approach uses traditional terms and concepts of music theory, but the approach itself is formal and uses the language of mathematics. The universal object is an audio wave; partials, sounds, and compositions are special objects, which are placed in a hierarchical order based on time scales. The objects have both static and dynamic attributes. When we realize a composition, we assign values to each of its attributes: a (scalar) value to a static attribute, an envelope and a size to a dynamic attribute. A composition is then a trajectory in the space of aural events, and the complex audio wave is its formal representation. Sounds are fibers in the space of aural events, from which the composer weaves the trajectory of a composition. Each sound object in turn is made up of partials, which are the elementary building blocks of any music composition. The partials evolve on the fastest time scale in the hierarchy of partials, sounds, and compositions. The ideas outlined in this article are being implemented in a digital instrument for additive sound synthesis and in software for music composition. A demonstration of some preliminary results has been submitted by the authors for presentation at the conference.

  13. Pragmatic approaches to genetic screening.

    PubMed

    Mallia, Pierre; ten Have, Henk

    2005-01-01

    Pragmatic approaches to genetic testing are discussed and appraised. Whilst there are various schools of pragmatism, the Deweyan approach seems to be the most appreciated in bioethics as it allows a historical approach indebted to Hegel. This in turn allows the pragmatist to specify and balance principles in various contexts. There are problems with where to draw a line between what is referred to here as the micro- and macro-level of doing bioethics, unless one is simply to be classified as a principlist. Whilst most discussions on genetics occur at a macro level, most specifying must be done also at a micro level - the clinical encounter. Whilst pragmatism encourages us to understand better social and scientific factors and puts into perspective statements like 'playing God', doubts are raised about the 'consensus' process and how one can put aside fundamental values such as the moral status of the embryo on which there is general disagreement. If those doing pragmatism do not endorse these values, there seems to be little ground for process and compromise with those who do. It seems therefore that pragmatism cannot ignore values, even those which are not endorsed by everyone.

  14. Neuromodulation: Selected approaches and challenges

    PubMed Central

    Parpura, Vladimir; Silva, Gabriel A.; Tass, Peter A.; Bennet, Kevin E.; Meyyappan, Meyya; Koehne, Jessica; Lee, Kendall H.; Andrews, Russell J.

    2012-01-01

    The brain operates through complex interactions in the flow of information and signal processing within neural networks. The “wiring” of such networks, being neuronal or glial, can physically and/or functionally go rogue in various pathological states. Neuromodulation, as a multidisciplinary venture, attempts to correct such faulty nets. In this review, selected approaches and challenges in neuromoduation are discussed. The use of water-dispersible carbon nanotubes have proven effective in modulation of neurite outgrowth in culture as well as in aiding regeneration after spinal cord injury in vivo. Studying neural circuits using computational biology and analytical engineering approaches brings to light geometrical mapping of dynamics within neural networks, much needed information for stimulation interventions in medical practice. Indeed, sophisticated desynchronization approaches used for brain stimulation have been successful in coaxing “misfiring” neuronal circuits to resume productive firing patterns in various human disorders. Devices have been developed for the real time measurement of various neurotransmitters as well as electrical activity in the human brain during electrical deep brain stimulation. Such devices can establish the dynamics of electrochemical changes in the brain during stimulation. With increasing application of nanomaterials in devices for electrical and chemical recording and stimulating in the brain, the era of cellular, and even intracellular, precision neuromodulation will soon be upon us. PMID:23190025

  15. [Pulmonary nodule: a bayesian approach].

    PubMed

    Meert, A-P

    2010-01-01

    A solitary pulmonary nodule is a common clinical problem. It is usually detected incidentally. The prevalence of solitary pulmonary nodule (SPN) in the lung cancer screening study varies from 8 to 50% (with a prevalence of malignant nodule from 1 to 13%). The bayesian approach can help us to identify promptly malignant nodule in order to treat them surgically and to avoid surgery for benign nodules. Therefore, it is needed to estimate the probability of cancer (Pca) in the SPN. Likelihood ratio (LR) for overall prevalence of malignancy and for different clinical and radiological information (age, smoking exposure, symptoms, cancer history, nodule size, spiculation, calcification, location, growth...) can be obtained from the literature. The odds of cancer-malignancy (odds ca) can be calculated by multiplying all of these LRs together. The Pca = odds ca/1+odds ca. Using this bayeasian approach, the probability of cancer based on an abnormal or normal fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) scan has been estimated. Sensitivity, specificity, positive predictive value and negative predictive value of PET scan are respectively about 90%, 83%, 92% and 90%. Moreover, the LR for malignancy are higher with an abnormal PET scan when compared to most clinical and radiological LRs. Today, the Bayesian approach of SPN must include PET scan.

  16. Computer Algebra, Instrumentation and the Anthropological Approach

    ERIC Educational Resources Information Center

    Monaghan, John

    2007-01-01

    This article considers research and scholarship on the use of computer algebra in mathematics education following the instrumentation and the anthropological approaches. It outlines what these approaches are, positions them with regard to other approaches, examines tensions between the two approaches and makes suggestions for how work in this…

  17. Synchronized Flashing Lights For Approach And Docking

    NASA Technical Reports Server (NTRS)

    Book, Michael L.; Howard, Richard T.; Bryan, Thomas C.; Bell, Joseph L.

    1994-01-01

    Proposed optoelectronic system for guiding vehicle in approaching and docking with another vehicle includes active optical targets (flashing lights) on approached vehicle synchronized with sensor and image-processing circuitry on approaching vehicle. Conceived for use in automated approach and docking of two spacecraft. Also applicable on Earth to manually controlled and automated approach and docking of land vehicles, aircraft, boats, and submersible vehicles, using GPS or terrestrial broadcast time signals for synchronization. Principal advantage: optical power reduced, with consequent enhancement of safety.

  18. Commercial dissemination approaches for solar home systems

    SciTech Connect

    Terrado, E.

    1997-12-01

    The author discusses the issue of providing solar home systems to primarily rural areas from the perspective of how to commercialize the process. He considers two different approaches, one an open market approach and the other an exclusive market approach. He describes examples of the exclusive market approach which are in process in Argentina and Brazil. Coming from a banking background, the business aspects are discussed in detail. He points out the strengths and weaknesses of both approaches toward developing such systems.

  19. Transcriptomic Approaches to Neural Repair

    PubMed Central

    Antunes-Martins, Ana; Chandran, Vijayendran; Costigan, Michael; Lerch, Jessica K.; Willis, Dianna E.; Tuszynski, Mark H.

    2015-01-01

    Understanding why adult CNS neurons fail to regenerate their axons following injury remains a central challenge of neuroscience research. A more complete appreciation of the biological mechanisms shaping the injured nervous system is a crucial prerequisite for the development of robust therapies to promote neural repair. Historically, the identification of regeneration associated signaling pathways has been impeded by the limitations of available genetic and molecular tools. As we progress into an era in which the high-throughput interrogation of gene expression is commonplace and our knowledge base of interactome data is rapidly expanding, we can now begin to assemble a more comprehensive view of the complex biology governing axon regeneration. Here, we highlight current and ongoing work featuring transcriptomic approaches toward the discovery of novel molecular mechanisms that can be manipulated to promote neural repair. SIGNIFICANCE STATEMENT Transcriptional profiling is a powerful technique with broad applications in the field of neuroscience. Recent advances such as single-cell transcriptomics, CNS cell type-specific and developmental stage-specific expression libraries are rapidly enhancing the power of transcriptomics for neuroscience applications. However, extracting biologically meaningful information from large transcriptomic datasets remains a formidable challenge. This mini-symposium will highlight current work using transcriptomic approaches to identify regulatory networks in the injured nervous system. We will discuss analytical strategies for transcriptomics data, the significance of noncoding RNA networks, and the utility of multiomic data integration. Though the studies featured here specifically focus on neural repair, the approaches highlighted in this mini-symposium will be of broad interest and utility to neuroscientists working in diverse areas of the field. PMID:26468186

  20. Approach to adolescent suicide prevention

    PubMed Central

    Kostenuik, Marcia; Ratnapalan, Mohana

    2010-01-01

    Abstract OBJECTIVE To provide family physicians with an approach to suicide prevention in youth. SOURCES OF INFORMATION A literature review was performed using Ovid MEDLINE with the key words suicide, attempted suicide, and evaluation studies or program evaluation, adolescent. MAIN MESSAGE Youth suicide might be prevented by earlier recognition and treatment of mental illness. Family physicians can and should screen for mental illness in youth; there are many diagnostic and treatment resources available to assist with this. CONCLUSION Earlier detection and treatment of mental illness are the most important ways family physicians can reduce morbidity and mortality for youth who are contemplating suicide. PMID:20705879

  1. Pharmacological approaches in celiac disease.

    PubMed

    McCarville, Justin L; Caminero, Alberto; Verdu, Elena F

    2015-12-01

    Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten, characterized by immune responses toward gluten constituents and the autoantigen transglutaminase 2. The only current treatment available for celiac disease is a gluten-free diet, however there are a plethora of therapies in development for the treatment of celiac disease (e.g. vaccine), management of symptoms while consuming gluten (e.g. Necator americanus) or adjuvant therapies in conjunction with the gluten-free diet (e.g. larazotide acetate). Current approaches in development target barrier function, immune responses, detoxifying gluten or sequestering gluten. Developing therapies include those targeting environmental factors, such as the microbiota or proteases.

  2. Disease management: a continuum approach.

    PubMed

    Harvey, N; DePue, D M

    1997-06-01

    Disease management is a comprehensive, integrated approach to managing the health of populations through the use of disease-specific standards and protocols and population segmentation. It has been increasing in popularity among integrated delivery systems (IDSs) and payers alike as a way to respond to competitive pressures and to shift care delivery from inpatient to alternative care sites. To successfully implement disease-management programs, IDSs must develop an organizational mind-set that stresses information-driven, evidence-based standards of care that are adhered to across a tightly integrated continuum of care.

  3. BFKL approach and dipole picture

    SciTech Connect

    Fadin, V. S.

    2009-03-23

    Inter-relation of the BFKL approach and the colour dipole model is discussed. In the case of scattering of colourless objects the colour singlet BFKL kernel can be taken in the special representation called Moebius form. In the leading order (LO) it coincides with the kernel of the colour dipole model. In the next-to-leading order (NLO) the quark parts of the Moebius form and the colour dipole kernel are in accord with each other, but the gluon parts do not agree. Possible sources of this discrepancy are analyzed.

  4. Renewable resources. A systematic approach

    SciTech Connect

    Campos-Lopez, E.

    1980-01-01

    The use of a renewable resource as a source of raw material for energy or simply for satisfaction of ecological needs, is a complex problem involving a series of disciplines, decisions at different levels, and intense, community participation. This book brings together a series of papers related to the use of renewable resources seen from different perspectives: from that of the biologist who searches for new techniques for the massive propagation of plants to the chemist who has found numerous chemical alternatives for the conversion of many sources of raw materials and energy to cellulose. The social and physical impacts of renewable resource exploitation are analyzed using different approaches.

  5. HEDR modeling approach: Revision 1

    SciTech Connect

    Shipler, D.B.; Napier, B.A.

    1994-05-01

    This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies.

  6. Atomic Approaches to Defect Thermochemistry

    DTIC Science & Technology

    1992-04-30

    ATOMIC APPROACHES TO DEFECT THERMOCHEMISTRY (AFOSR-89-0309) for period 1 April 1989 to 31 March 1992 Submitted by Professor James A. Van Vechten and...could be very much less. Thus, the GaAs lattice is indeed found to be stiff. Positron annihilation experiments (17) also teach us that GaAs samples...to be less for Si than for Ge. Experience with chemical trends of bond strengths, as well as the empirical literature, teach us that the H bond

  7. Orthodontic-periodontics interdisciplinary approach.

    PubMed

    Vinod, K; Reddy, Y Giridhar; Reddy, Vinay P; Nandan, Hemant; Sharma, Meenakshi

    2012-01-01

    In this present era, when a significant number of patients seeking orthodontic treatment are adults, importance of multidisciplinary treatment approach cannot be overemphasized. Higher susceptibility of plaque accumulation in patients undergoing orthodontic treatment makes involvement of periodontist almost unavoidable. Also, orthodontic treatment frequently results in undesirable periodontal changes which require immediate attention. More recently, orthodontics has been used as an adjunct to periodontics to increase connective tissue support and alveolar bone height. The purpose of this article is to review the adverse effects of orthodontic treatment on the periodontal tissues and to discuss the mutually beneficial relationship shared between the two specialties.

  8. Novel Approaches for Glycodrug Discovery

    NASA Astrophysics Data System (ADS)

    Kondo, Hirosato

    This chapter will give you an overview of recent approaches for drug development, focusing on the function and roles of carbohydrates. Section 2 will outline the biochemical functions of polysaccharide (neutral polysaccharide, chitin and chitosan, glycosaminoglycan, and synthetic polysaccharides) and glycopolymers and the perspectives of their medicinal/medical use. Section 3 will outline recent biopharmaceutical research and development, utilizing the functions of carbohydrates. Section 4 will outline drug discovery and development of new medicines targeting carbohydrates. In addition, recent advances in carbohydrate synthesis technology, needed for development of new medicines, will also be described.

  9. An approach to space power

    NASA Technical Reports Server (NTRS)

    Miley, G. H.; Nadler, J. H.; Hochberg, T.; Barnouin, O.; Gu, Y. B.

    1990-01-01

    Fusion offers the potential for a very high specific power, providing a large specific impulse that can be traded-off with thrust for mission optimization. Thus fusion is a leading candidate for missions beyond the moon. A new approach is discussed for space fusion power, namely Inertial Electrostatic Confinement (IEC). This method offers a high power density in a relatively small, simple device. It appears capable of burning aneutronic fuels which are most desirable for space applications and is well suited for direct conversion. An experimental device to test the concept is described.

  10. Educational approaches for discouraging plagiarism.

    PubMed

    Fischer, Beth A; Zigmond, Michael J

    2011-01-01

    Suggested approaches to reduce the occurrence of plagiarism in academia, particularly among trainees. These include (1) educating individuals as to the definition of plagiarism and its consequences through written guidelines, active discussions, and practice in identifying proper and improper citation practices; (2) distributing checklists that break the writing task into more manageable steps, (3) requiring the submission of an outline and then a first draft prior to the deadline for a paper; (4) making assignments relevant to individual interests; and (5) providing trainees with access to software programs that detect plagiarism.

  11. Approaches to wind resource verification

    NASA Technical Reports Server (NTRS)

    Barchet, W. R.

    1982-01-01

    Verification of the regional wind energy resource assessments produced by the Pacific Northwest Laboratory addresses the question: Is the magnitude of the resource given in the assessments truly representative of the area of interest? Approaches using qualitative indicators of wind speed (tree deformation, eolian features), old and new data of opportunity not at sites specifically chosen for their exposure to the wind, and data by design from locations specifically selected to be good wind sites are described. Data requirements and evaluation procedures for verifying the resource are discussed.

  12. Approach to Mars Field Geology

    NASA Technical Reports Server (NTRS)

    Muehlberger, William; Rice, James W.; Parker, Timothy; Lipps, Jere H.; Hoffman, Paul; Burchfiel, Clark; Brasier, Martin

    1998-01-01

    The goals of field study on Mars are nothing less than to understand the processes and history of the planet at whatever level of detail is necessary. A manned mission gives us an unprecedented opportunity to use the immense power of the human mind to comprehend Mars in extraordinary detail. To take advantage of this opportunity, it is important to examine how we should approach the field study of Mars. In this effort, we are guided by over 200 years of field exploration experience on Earth as well as six manned missions exploring the Moon.

  13. Specialist approaches to managing lipoedema.

    PubMed

    Fetzer, Amy

    2016-04-01

    While there is no proven cure for lipoedema, early detection is key as specialist treatments, complemented by self-management techniques, can improve symptoms and prevent progression. There is no universal approach as the correct treatment or treatments will depend on each patient's particular circumstances; however, when chosen early and appropriately, interventions can provide huge benefits. The most common treatments in the management of lipoedema include compression, manual lymphatic drainage (MLD), tumescent liposuction, intermittent pneumatic compression therapy (IPC), kinesio taping, deep oscillation therapy, and cognitive behavioural therapy (CBT).

  14. 'Lean' approach gives greater efficiency.

    PubMed

    Call, Roger

    2014-02-01

    Adapting the 'Lean' methodologies used for many years by many manufacturers on the production line - such as in the automotive industry - and deploying them in healthcare 'spaces' can, Roger Call, an architect at Herman Miller Healthcare in the US, argues, 'easily remedy many of the inefficiencies' found within a healthcare facility. In an article that first appeared in the September 2013 issue of The Australian Hospital Engineer, he explains how 'Lean' approaches such as the 'Toyota production system', and 'Six Sigma', can be harnessed to good effect in the healthcare sphere.

  15. Orthodontic–periodontics interdisciplinary approach

    PubMed Central

    Vinod, K.; Reddy, Y. Giridhar; Reddy, Vinay P.; Nandan, Hemant; Sharma, Meenakshi

    2012-01-01

    In this present era, when a significant number of patients seeking orthodontic treatment are adults, importance of multidisciplinary treatment approach cannot be overemphasized. Higher susceptibility of plaque accumulation in patients undergoing orthodontic treatment makes involvement of periodontist almost unavoidable. Also, orthodontic treatment frequently results in undesirable periodontal changes which require immediate attention. More recently, orthodontics has been used as an adjunct to periodontics to increase connective tissue support and alveolar bone height. The purpose of this article is to review the adverse effects of orthodontic treatment on the periodontal tissues and to discuss the mutually beneficial relationship shared between the two specialties. PMID:22628956

  16. A Logical Approach to Entanglement

    NASA Astrophysics Data System (ADS)

    Das, Abhishek

    2016-10-01

    In this paper we innovate a logical approach to develop an intuition regarding the phenomenon of quantum entanglement. In the vein of the logic introduced we substantiate that particles that were entangled in the past will be entangled in perpetuity and thereby abide a rule that restricts them to act otherwise. We also introduce a game and by virtue of the concept of Nash equilibrium we have been able to show that entangled particles will mutually correspond to an experiment that is performed on any one of the particle.

  17. Nanoparticle Approaches against Bacterial Infections

    PubMed Central

    Gao, Weiwei; Thamphiwatana, Soracha; Angsantikul, Pavimol; Zhang, Liangfang

    2014-01-01

    Despite the wide success of antibiotics, the treatment of bacterial infection still faces significant challenges, particularly the emergence of antibiotic resistance. As a result, nanoparticle drug delivery platforms including liposomes, polymeric nanoparticles, dendrimers, and various inorganic nanoparticles have been increasingly exploited to enhance the therapeutic effectiveness of existing antibiotics. This review focuses on areas where nanoparticle approaches hold significant potential to advance the treatment of bacterial infection. These areas include targeted antibiotic delivery, environmentally responsive antibiotic delivery, combinatorial antibiotic delivery, nanoparticle-enabled antibacterial vaccination, and nanoparticle-based bacterial detection. In each area we highlight the innovative antimicrobial nanoparticle platforms and review their progress made against bacterial infections. PMID:25044325

  18. Soliton approach to magnetic holes

    NASA Astrophysics Data System (ADS)

    Baumgärtel, Klaus

    ``Magnetic holes'' (MHs), depressions in the magnetic field magnitude associated with enhancements in density and kinetic pressure, have been observed in the solar wind, the magnetosheaths of terrestrial planets and in the environments of comets, suggesting that this phenomenon may be a common occurrence in space plasmas. MHs are usually believed to result from the mirror instability which can develop in high-beta plasmas with a temperature anisotropy, T⊥/T∥>1. Motivated by the fact that solar wind MHs are often observed in a mirror mode stable environment [Winterhalter et al., 1994], this paper proposes a mechanism for the maintenance of MHs in an equilibrium plasma. We suggest an explanation in terms of magnetically rarefactive (``dark'') MHD solitons with anticorrelation of magnetic field and density, which propagate with small velocities at large angles to the ambient magnetic field. This intrinsically nonlinear approach is based on a magnetohydrodynamic plasma description including Hall inertia effects and utilizes the well-developed soliton theory of the Derivative Nonlinear Schrödinger Equation (DNLS) which appears as a partly adequate approximation to the parent Hall-MHD system. The approach introduces an alternative mechanism into the discussion over the physical nature of MHs that is not related to an instability and provides an explanation for various aspects of the observations including amplitude, thickness, and spatial structure of MHs.

  19. Earthquake Archaeology: a logical approach?

    NASA Astrophysics Data System (ADS)

    Stewart, I. S.; Buck, V. A.

    2001-12-01

    Ancient earthquakes can leave their mark in the mythical and literary accounts of ancient peoples, the stratigraphy of their site histories, and the structural integrity of their constructions. Within this broad cross-disciplinary tramping ground, earthquake geologists have tended to focus on those aspects of the cultural record that are most familiar to them; the physical effects of seismic deformation on ancient constructions. One of the core difficulties with this 'earthquake archaeology' approach is that recent attempts to isolate structural criteria that are diagnostic or strongly suggestive of a seismic origin are undermined by the recognition that signs of ancient seismicity are generally indistinguishable from non-seismic mechanisms (poor construction, adverse geotechnical conditions). We illustrate the difficulties and inconsistencies in current proposed 'earthquake diagnostic' schemes by reference to two case studies of archaeoseismic damage in central Greece. The first concerns fallen columns at various Classical temple localities in mainland Greece (Nemea, Sounio, Olympia, Bassai) which, on the basis of observed structural criteria, are earthquake-induced but which are alternatively explained by archaeologists as the action of human disturbance. The second re-examines the almost type example of the Kyparissi site in the Atalanti region as a Classical stoa offset across a seismic surface fault, arguing instead for its deformation by ground instability. Finally, in highlighting the inherent ambiguity of archaeoseismic data, we consider the value of a logic-tree approach for quantifying and quantifying our uncertainities for seismic-hazard analysis.

  20. The Final Approach Spacing Tool

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Bergh, Christopher; Krzeczowski, Ken J.; Schlickenmaier, H. W. (Technical Monitor)

    1994-01-01

    A system for assisting terminal area air traffic controllers in the management and control of arrival traffic, referred to as the Final Approach Spacing Tool (FAST), is being developed at NASA Ames Research Center. In a cooperative program, NASA and FAA have efforts underway to install and evaluate the system at the Dallas/Fort Worth Terminal Radar Approach Control facility. This paper will review the software architecture, the algorithms components, and the human-machine interface. The system is based on continuous updates of a detailed trajectory analyses of all arrival aircraft. FAST interprets the results of these trajectory analyses to build an efficient and procedurally acceptable plan for the arrival traffic that consists of a sequence, schedule, and runway assignment. The system utilizes a heuristically-based conflict resolution algorithm to build a solution trajectory that satisfies the plan, It extracts a series of speed and heading advisories from the solution trajectory to assist the controller in efficiently managing and controlling the arrival traffic down to the runway. The advisories are displayed in a graphical format to the controller. In addition to the radar tracking data, the system also relies on a series of data bases. These data bases contain aircraft performance models, airline preferred operational procedures, airspace structure, air traffic procedural models, and a three dimensional wind model. Field evaluation of FAST is expected to begin in 1994.

  1. Boom Rendezvous Alternative Docking Approach

    NASA Technical Reports Server (NTRS)

    Bonometti, Joseph A.

    2006-01-01

    Space rendezvous and docking has always been attempted with primarily one philosophic methodology. The slow matching of one vehicle's orbit by a second vehicle and then a final closing sequence that ends in matching the orbits with perfect precision and with near zero relative velocities. The task is time consuming, propellant intensive, risk inherent (plume impingement, collisions, fuel depletion, etc.) and requires substantial hardware mass. The historical background and rationale as to why this approach is used is discussed in terms of the path-not-taken and in light of an alternate methodology. Rendezvous and docking by boom extension is suggested to have inherent advantages that today s technology can readily exploit. Extension from the primary spacecraft, beyond its inherent large inertia, allows low inertia connections to be made rapidly and safely. Plume contamination issues are eliminated as well as the extra propellant mass and risk required for the final thruster (docking) operations. Space vehicle connection hardware can be significantly lightened. Also, docking sensors and controls require less fidelity; allowing them to be more robust and less sensitive. It is the potential safety advantage and mission risk reduction that makes this approach attractive, besides the prospect of nominal time and mass savings.

  2. Snow metamorphism: A fractal approach.

    PubMed

    Carbone, Anna; Chiaia, Bernardino M; Frigo, Barbara; Türk, Christian

    2010-09-01

    Snow is a porous disordered medium consisting of air and three water phases: ice, vapor, and liquid. The ice phase consists of an assemblage of grains, ice matrix, initially arranged over a random load bearing skeleton. The quantitative relationship between density and morphological characteristics of different snow microstructures is still an open issue. In this work, a three-dimensional fractal description of density corresponding to different snow microstructure is put forward. First, snow density is simulated in terms of a generalized Menger sponge model. Then, a fully three-dimensional compact stochastic fractal model is adopted. The latter approach yields a quantitative map of the randomness of the snow texture, which is described as a three-dimensional fractional Brownian field with the Hurst exponent H varying as continuous parameters. The Hurst exponent is found to be strongly dependent on snow morphology and density. The approach might be applied to all those cases where the morphological evolution of snow cover or ice sheets should be conveniently described at a quantitative level.

  3. Immunotherapeutic Approaches to Alzheimer's Disease

    NASA Astrophysics Data System (ADS)

    Monsonego, Alon; Weiner, Howard L.

    2003-10-01

    Although neurodegenerative diseases such as Alzheimer's disease are not classically considered mediated by inflammation or the immune system, in some instances the immune system may play an important role in the degenerative process. Furthermore, it has become clear that the immune system itself may have beneficial effects in nervous system diseases considered neurodegenerative. Immunotherapeutic approaches designed to induce a humoral immune response have recently been developed for the treatment of Alzheimer's disease. These studies have led to human trials that resulted in both beneficial and adverse effects. In animal models, it has also been shown that immunotherapy designed to induce a cellular immune response may be of benefit in central nervous system injury, although T cells may have either a beneficial or detrimental effect depending on the type of T cell response induced. These areas provide a new avenue for exploring immune system-based therapy of neurodegenerative diseases and will be discussed here with a primary focus on Alzheimer's disease. We will also discuss how these approaches affect microglia activation, which plays a key role in therapy of such diseases.

  4. Systematic approach to thermal leptogenesis

    NASA Astrophysics Data System (ADS)

    Frossard, T.; Garny, M.; Hohenegger, A.; Kartavtsev, A.; Mitrouskas, D.

    2013-04-01

    In this work we study thermal leptogenesis using nonequilibrium quantum field theory. Starting from fundamental equations for correlators of the quantum fields we describe the steps necessary to obtain quantum-kinetic equations for quasiparticles. These can easily be compared to conventional results and overcome conceptional problems inherent in the canonical approach. Beyond CP-violating decays we include also those scattering processes which are tightly related to the decays in a consistent approximation of fourth order in the Yukawa couplings. It is demonstrated explicitly how the S-matrix elements for the scattering processes in the conventional approach are related to two- and three-loop contributions to the effective action. We derive effective decay and scattering amplitudes taking medium corrections and thermal masses into account. In this context we also investigate CP-violating Higgs decay within the same formalism. From the kinetic equations we derive rate equations for the lepton asymmetry improved in that they include quantum-statistical effects and medium corrections to the quasiparticle properties.

  5. Microfluidic approaches to malaria detection.

    PubMed

    Gascoyne, Peter; Satayavivad, Jutamaad; Ruchirawat, Mathuros

    2004-02-01

    Microfluidic systems are under development to address a variety of medical problems. Key advantages of micrototal analysis systems based on microfluidic technology are the promise of small size and the integration of sample handling and measurement functions within a single, automated device having low mass-production costs. Here, we review the spectrum of methods currently used to detect malaria, consider their advantages and disadvantages, and discuss their adaptability towards integration into small, automated micro total analysis systems. Molecular amplification methods emerge as leading candidates for chip-based systems because they offer extremely high sensitivity, the ability to recognize malaria species and strain, and they will be adaptable to the detection of new genotypic signatures that will emerge from current genomic-based research of the disease. Current approaches to the development of chip-based molecular amplification are considered with special emphasis on flow-through PCR, and we present for the first time the method of malaria specimen preparation by dielectrophoretic field-flow-fractionation. Although many challenges must be addressed to realize a micrototal analysis system for malaria diagnosis, it is concluded that the potential benefits of the approach are well worth pursuing.

  6. Multidisciplinary approaches to solar hydrogen

    PubMed Central

    Bren, Kara L.

    2015-01-01

    This review summarizes three different approaches to engineering systems for the solar-driven evolution of hydrogen fuel from water: molecular, nanomaterials and biomolecular. Molecular systems have the advantage of being highly amenable to modification and detailed study and have provided great insight into photophysics, electron transfer and catalytic mechanism. However, they tend to display poor stability. Systems based on nanomaterials are more robust but also are more difficult to synthesize in a controlled manner and to modify and study in detail. Biomolecular systems share many properties with molecular systems and have the advantage of displaying inherently high efficiencies for light absorption, electron–hole separation and catalysis. However, biological systems must be engineered to couple modules that capture and convert solar photons to modules that produce hydrogen fuel. Furthermore, biological systems are prone to degradation when employed in vitro. Advances that use combinations of these three tactics also are described. Multidisciplinary approaches to this problem allow scientists to take advantage of the best features of biological, molecular and nanomaterials systems provided that the components can be coupled for efficient function. PMID:26052425

  7. Hybrid metrology implementation: server approach

    NASA Astrophysics Data System (ADS)

    Osorio, Carmen; Timoney, Padraig; Vaid, Alok; Elia, Alex; Kang, Charles; Bozdog, Cornel; Yellai, Naren; Grubner, Eyal; Ikegami, Toru; Ikeno, Masahiko

    2015-03-01

    Hybrid metrology (HM) is the practice of combining measurements from multiple toolset types in order to enable or improve metrology for advanced structures. HM is implemented in two phases: Phase-1 includes readiness of the infrastructure to transfer processed data from the first toolset to the second. Phase-2 infrastructure allows simultaneous transfer and optimization of raw data between toolsets such as spectra, images, traces - co-optimization. We discuss the extension of Phase-1 to include direct high-bandwidth communication between toolsets using a hybrid server, enabling seamless fab deployment and further laying the groundwork for Phase-2 high volume manufacturing (HVM) implementation. An example of the communication protocol shows the information that can be used by the hybrid server, differentiating its capabilities from that of a host-based approach. We demonstrate qualification and production implementation of the hybrid server approach using CD-SEM and OCD toolsets for complex 20nm and 14nm applications. Finally we discuss the roadmap for Phase-2 HM implementation through use of the hybrid server.

  8. Modeling Approaches in Planetary Seismology

    NASA Technical Reports Server (NTRS)

    Weber, Renee; Knapmeyer, Martin; Panning, Mark; Schmerr, Nick

    2014-01-01

    Of the many geophysical means that can be used to probe a planet's interior, seismology remains the most direct. Given that the seismic data gathered on the Moon over 40 years ago revolutionized our understanding of the Moon and are still being used today to produce new insight into the state of the lunar interior, it is no wonder that many future missions, both real and conceptual, plan to take seismometers to other planets. To best facilitate the return of high-quality data from these instruments, as well as to further our understanding of the dynamic processes that modify a planet's interior, various modeling approaches are used to quantify parameters such as the amount and distribution of seismicity, tidal deformation, and seismic structure on and of the terrestrial planets. In addition, recent advances in wavefield modeling have permitted a renewed look at seismic energy transmission and the effects of attenuation and scattering, as well as the presence and effect of a core, on recorded seismograms. In this chapter, we will review these approaches.

  9. Novel approaches in cancer immunotherapy.

    PubMed

    Subramaniam, Deepa S; Liu, Stephen V; Giaccone, Giuseppe

    2016-04-01

    Our understanding of tumor immunology has exploded in the past 3 decades. The complex relationships between tumor cells, the tumor microenvironment and the immune system cells, especially the cytotoxic and helper T cells and the regulatory T cells are beginning to be elucidated. In this review, we will attempt to provide a brief primer of tumor immunology. Cytokine therapy has historically been the mainstay of immunotherapy in cancers such as melanoma and kidney cancer. We will review some of the advances made with cancer vaccines, with a focus on peptide vaccines, tumor cell vaccines and immune cell vaccines. The pros and cons of nucleic acid-based vaccines including DNA and RNA vaccines will be discussed. Adoptive cell therapy has made significant progress utilizing chimeric antigen-receptor transduced T cells, especially in hematologic malignancies. We will also consider the key targets in checkpoint inhibition, and summarize some of the preclinical and clinical data with respect to checkpoint inhibition. Progress made in the novel immunotherapeutic approach of oncolytic viral therapy will be analyzed. PDL-1 expression by tumor cells and tumor infiltrating lymphocytes has been looked at as a biomarker in clinical trials. Limitations to such an approach and potential candidates for future predictive biomarkers of response to immunotherapy and biomarkers of autoimmunity and adverse reactions will be considered.

  10. Economics of a multimedia approach

    SciTech Connect

    Phillips, J.B.; Hindawi, M.A.

    1996-02-01

    One of the major driving forces in the decision of a facility operator to implement a multimedia approach to examining pollution is the economics of the situation. A multimedia approach has gained favor with many facility operators because it has been shown to be more cost-effective than dealing with a number of phases, or media, separately. To a great extent, this is due to elimination of inefficiencies involved with cross-media transfer of pollutants. Even more basic to the problem of industrial pollution is the generation of waste. All industrial processes yield some percentage of waste products, but frequently during the design phase the costs associated with producing wastes are underestimated. As part of this series on multimedia issues, the costs related to manufacturing waste products are examined in detail. An obvious inefficiency associated with waste generation is the loss of material that potentially could be converted to salable products. The value of commodity raw materials frequently is ignored when considering the total costs of pollution generation at an industrial facility. Although the economics of pollution generation are affected by a number of factors, including regulatory costs, disposal costs and impacts on health and safety, this article focuses on the economics of lost production in industrial facilities.

  11. Approach/avoidance in dreams.

    PubMed

    Malcolm-Smith, Susan; Koopowitz, Sheri; Pantelis, Eleni; Solms, Mark

    2012-03-01

    The influential threat simulation theory (TST) asserts that dreaming yields adaptive advantage by providing a virtual environment in which threat-avoidance may be safely rehearsed. We have previously found the incidence of biologically threatening dreams to be around 20%, with successful threat avoidance occurring in approximately one-fifth of such dreams. TST asserts that threat avoidance is over-represented relative to other possible dream contents. To begin assessing this issue, we contrasted the incidence of 'avoidance' dreams with that of their opposite: 'approach' dreams. Because TST states that the threat-avoidance function is only fully activated in ecologically valid (biologically threatening) contexts, we also performed this contrast for populations living in both high- and low-threat environments. We find that 'approach' dreams are significantly more prevalent across both contexts. We suggest these results are more consistent with the view that dreaming is generated by reward-seeking systems than by fear-conditioning systems, although reward-seeking is clearly not the only factor determining the content of dreams.

  12. Fast approach for toner saving

    NASA Astrophysics Data System (ADS)

    Safonov, Ilia V.; Kurilin, Ilya V.; Rychagov, Michael N.; Lee, Hokeun; Kim, Sangho; Choi, Donchul

    2011-01-01

    Reducing toner consumption is an important task in modern printing devices and has a significant positive ecological impact. Existing toner saving approaches have two main drawbacks: appearance of hardcopy in toner saving mode is worse in comparison with normal mode; processing of whole rendered page bitmap requires significant computational costs. We propose to add small holes of various shapes and sizes to random places inside a character bitmap stored in font cache. Such random perforation scheme is based on processing pipeline in RIP of standard printer languages Postscript and PCL. Processing of text characters only, and moreover, processing of each character for given font and size alone, is an extremely fast procedure. The approach does not deteriorate halftoned bitmap and business graphics and provide toner saving for typical office documents up to 15-20%. Rate of toner saving is adjustable. Alteration of resulted characters' appearance is almost indistinguishable in comparison with solid black text due to random placement of small holes inside the character regions. The suggested method automatically skips small fonts to preserve its quality. Readability of text processed by proposed method is fine. OCR programs process that scanned hardcopy successfully too.

  13. The acousto-ultrasonic approach

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1987-01-01

    The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

  14. Approaches for modeling magnetic nanoparticle dynamics

    PubMed Central

    Reeves, Daniel B; Weaver, John B

    2014-01-01

    Magnetic nanoparticles are useful biological probes as well as therapeutic agents. There have been several approaches used to model nanoparticle magnetization dynamics for both Brownian as well as Néel rotation. The magnetizations are often of interest and can be compared with experimental results. Here we summarize these approaches including the Stoner-Wohlfarth approach, and stochastic approaches including thermal fluctuations. Non-equilibrium related temperature effects can be described by a distribution function approach (Fokker-Planck equation) or a stochastic differential equation (Langevin equation). Approximate models in several regimes can be derived from these general approaches to simplify implementation. PMID:25271360

  15. Three approaches to reliability analysis

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.

    1989-01-01

    It is noted that current reliability analysis tools differ not only in their solution techniques, but also in their approach to model abstraction. The analyst must be satisfied with the constraints that are intrinsic to any combination of solution technique and model abstraction. To get a better idea of the nature of these constraints, three reliability analysis tools (HARP, ASSIST/SURE, and CAME) were used to model portions of the Integrated Airframe/Propulsion Control System architecture. When presented with the example problem, all three tools failed to produce correct results. In all cases, either the tool or the model had to be modified. It is suggested that most of the difficulty is rooted in the large model size and long computational times which are characteristic of Markov model solutions.

  16. How to approach chronic anemia.

    PubMed

    Koury, Mark J; Rhodes, Melissa

    2012-01-01

    We present herein an approach to diagnosing the cause of chronic anemia based on a patient's history and complete blood cell count (CBC). Four patterns that are encountered frequently in CBCs associated with chronic anemias are considered: (1) anemia with abnormal platelet and/or leukocyte counts, (2) anemia with increased reticulocyte counts, (3) life-long history of chronic anemia, and (4) anemia with inappropriately low reticulocytes. The pathophysiologic bases for some chronic anemias with low reticulocyte production are reviewed in terms of the bone marrow (BM) events that reduce normal rates of erythropoiesis. These events include: apoptosis of erythroid progenitor and precursor cells by intrinsic and extrinsic factors, development of macrocytosis when erythroblast DNA replication is impaired, and development of microcytosis due to heme-regulated eIF2α kinase inhibition of protein synthesis in iron-deficient or thalassemic erythroblasts.

  17. Episodic Memory: A Comparative Approach

    PubMed Central

    Martin-Ordas, Gema; Call, Josep

    2013-01-01

    Historically, episodic memory has been described as autonoetic, personally relevant, complex, context-rich, and allowing mental time travel. In contrast, semantic memory, which is theorized to be free of context and personal relevance, is noetic and consists of general knowledge of facts about the world. The field of comparative psychology has adopted this distinction in order to study episodic memory in non-human animals. Our aim in this article is not only to reflect on the concept of episodic memory and the experimental approaches used in comparative psychology to study this phenomenon, but also to provide a critical analysis of these paradigms. We conclude the article by providing new avenues for future research. PMID:23781179

  18. Environmental management: A system approach

    NASA Astrophysics Data System (ADS)

    Petak, William J.

    1981-05-01

    This paper presents a system framework whose purpose is to improve understanding of environmental management. By analyzing the links between elements of the environmental management system, it is possible to construct a model that aids thinking systematically about the decision-making subsystem, and other subsystems, of the entire environmental management system. Through a multidisciplinary environmental approach, each of the individual subsystems is able to adapt to threats and opportunities. The fields of government, market economics, social responsibility and ecology, for example, are so complex that it is extremely difficult to develop a framework that gives full consideration to all aspects. This paper, through the application of a highly idealized system framework, attempts to show the general relationships that exist between complex system elements.

  19. Nanomedicine Approaches for Corneal Diseases

    PubMed Central

    Chaurasia, Shyam S.; Lim, Rayne R.; Lakshminarayanan, Rajamani; Mohan, Rajiv R.

    2015-01-01

    Corneal diseases are the third leading cause of blindness globally. Topical nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, antibiotics and tissue transplantation are currently used to treat corneal pathological conditions. However, barrier properties of the ocular surface necessitate high concentration of the drugs applied in the eye repeatedly. This often results in poor efficacy and several side-effects. Nanoparticle-based molecular medicine seeks to overcome these limitations by enhancing the permeability and pharmacological properties of the drugs. The promise of nanomedicine approaches for treating corneal defects and restoring vision without side effects in preclinical animal studies has been demonstrated. Numerous polymeric, metallic and hybrid nanoparticles capable of transporting genes into desired corneal cells to intercept pathologic pathways and processes leading to blindness have been identified. This review provides an overview of corneal diseases, nanovector properties and their applications in drug-delivery and corneal disease management. PMID:25941990

  20. Cognitive effort: A neuroeconomic approach

    PubMed Central

    Braver, Todd S.

    2015-01-01

    Cognitive effort has been implicated in numerous theories regarding normal and aberrant behavior and the physiological response to engagement with demanding tasks. Yet, despite broad interest, no unifying, operational definition of cognitive effort itself has been proposed. Here, we argue that the most intuitive and epistemologically valuable treatment is in terms of effort-based decision-making, and advocate a neuroeconomics-focused research strategy. We first outline psychological and neuroscientific theories of cognitive effort. Then we describe the benefits of a neuroeconomic research strategy, highlighting how it affords greater inferential traction than do traditional markers of cognitive effort, including self-reports and physiologic markers of autonomic arousal. Finally, we sketch a future series of studies that can leverage the full potential of the neuroeconomic approach toward understanding the cognitive and neural mechanisms that give rise to phenomenal, subjective cognitive effort. PMID:25673005

  1. Immunotherapeutic approaches for Alzheimer's disease.

    PubMed

    Wisniewski, Thomas; Goñi, Fernando

    2015-03-18

    Alzheimer's disease (AD) is the most prevalent form of dementia worldwide and is an emerging global epidemic. It is characterized by an imbalance between production and clearance of amyloid β (Aβ) and tau proteins. Oligomeric forms of Aβ and tau are believed to be the most toxic. Dramatic results from AD animal models showed great promise for active and passive immune therapies targeting Aβ. However, there is very limited evidence in human studies of the clinical benefits from these approaches. Immunotherapies targeting only tau pathology have had some success but are limited so far to mouse models. The majority of current methods is based on immunological targeting of a self-protein; hence, benefits need to be balanced against risks of stimulating excessive autoimmune toxic inflammation. For greater efficacy the next generation of vaccines needs to focus more on concurrently targeting all the intermediate toxic conformers of oligomeric Aβ and tau species.

  2. Synthetic approaches to multifunctional indenes

    PubMed Central

    López-Pérez, Sara; Dinarès, Immaculada

    2011-01-01

    Summary The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones. PMID:22238553

  3. Henipavirus pathogenesis and antiviral approaches.

    PubMed

    Mathieu, Cyrille; Horvat, Branka

    2015-03-01

    Hendra virus and Nipah virus are closely related, recently emerged zoonotic paramyxoviruses, belonging to the Henipavirus genus. Both viruses induce generalized vasculitis affecting particularly the respiratory tract and CNS. The exceptionally broad species tropism of Henipavirus, the high case fatality rate and person-to-person transmission associated with Nipah virus outbreaks emphasize the necessity of effective antiviral strategies for these intriguing threatening pathogens. Current therapeutic approaches, validated in animal models, target early steps in viral infection; they include the use of neutralizing virus-specific antibodies and blocking membrane fusion with peptides that bind the viral fusion protein. A better understanding of Henipavirus pathogenesis is critical for the further advancement of antiviral treatment, and we summarize here the recent progress in the field.

  4. Therapeutic approaches for celiac disease

    PubMed Central

    Plugis, Nicholas M.; Khosla, Chaitan

    2015-01-01

    Celiac disease is a common, lifelong autoimmune disorder for which dietary control is the only accepted form of therapy. A strict gluten-free diet is burdensome to patients and can be limited in efficacy, indicating there is an unmet need for novel therapeutic approaches to supplement or supplant dietary therapy. Many molecular events required for disease pathogenesis have been recently characterized and inspire most current and emerging drug-discovery efforts. Genome-wide association studies (GWAS) confirm the importance of human leukocyte antigen genes in our pathogenic model and identify a number of new risk loci in this complex disease. Here, we review the status of both emerging and potential therapeutic strategies in the context of disease pathophysiology. We conclude with a discussion of how genes identified during GWAS and follow-up studies that enhance susceptibility may offer insight into developing novel therapies. PMID:26060114

  5. Prereferral intervention: a prescriptive approach.

    PubMed

    Fuchs, D; Fuchs, L S; Bahr, M W; Fernstrom, P; Stecker, P M

    1990-04-01

    This investigation assessed effects of three increasingly inclusive versions of the Behavioral Consultation (BC) model on problem behavior of students in mainstream classrooms in an effort to develop an effective and efficient approach to prereferral intervention. Subjects were 43 general educators, their 43 most difficult-to-teach students (without disabilities), and 12 school consultants, representing seven inner-city middle schools. Teachers and students were assigned to three BC groups, representing least (BC 1), more (BC 2), and most (BC 3) inclusive variants of BC, and one control group. Preintervention, postintervention, and follow-up observations of student behavior indicated that more inclusive BC versions exerted stronger effects than the least inclusive variant in reducing problem behavior. Theoretical and practical implications for consultation-related activity are discussed.

  6. Clinical indicators: a methodological approach.

    PubMed

    Scott, L; Grimmer, K

    1995-03-01

    Clinical indicators offer physiotherapists a tool by which quality of care can be flagged and evaluated. Such a flag requires a measure of the cost of treatment as well as the outcome achieved for that cost. Traditionally, the number of treatments to discharge has been used as a proxy measure of cost as well as outcome of physiotherapy care. However, physiotherapists recognize that the cost of treatment is an inappropriate reflection of the outcome of care in many instances. The challenge for physiotherapists in developing clinical indicators is to set appropriate flags of quality of care. This paper presents a methodological approach to the development of a flag of performance for acute lower back pain.

  7. Postoperative singultus: an osteopathic approach.

    PubMed

    Petree, Kristie; Bruner, Jonathan

    2015-03-01

    Singultus, or hiccups, is a common medical condition. Despite exponential leaps in medicine, the pathophysiologic cause remains poorly defined. Persistent singultus has been associated with conditions such as pulmonary embolism and myocardial infarction. Singultus is also a well-known postoperative complication. The criterion standard of care for patients with singultus involves ruling out lethal pathologic causes, attempting physical stimulation with Valsava maneuvers or drinking water, and, if no relief has been achieved, administering drugs to ease the symptoms. The authors report a case of a man whose postoperative singultus was successfully managed with osteopathic manipulative treatment. This approach addresses many of the possible underlying neuromechanical causes of the aberrant reflex with minimal potential for adverse effects. Physicians should consider osteopathic manipulative treatment in the care of patients with singultus.

  8. Approaches to chemical synthetic biology.

    PubMed

    Chiarabelli, Cristiano; Stano, Pasquale; Anella, Fabrizio; Carrara, Paolo; Luisi, Pier Luigi

    2012-07-16

    Synthetic biology is first represented in terms of two complementary aspects, the bio-engineering one, based on the genetic manipulation of extant microbial forms in order to obtain forms of life which do not exist in nature; and the chemical synthetic biology, an approach mostly based on chemical manipulation for the laboratory synthesis of biological structures that do not exist in nature. The paper is mostly devoted to shortly review chemical synthetic biology projects currently carried out in our laboratory. In particular, we describe: the minimal cell project, then the "Never Born Proteins" and lastly the Never Born RNAs. We describe and critically analyze the main results, emphasizing the possible relevance of chemical synthetic biology for the progress in basic science and biotechnology.

  9. Topological approach of Jungian psychology.

    PubMed

    Viret, Jacques

    2010-09-01

    In this work, we compare two global approaches which are usually considered as completely unconnected one with the other. The former is Thom's topology and the latter is Jung's psychology. More precisely, it seemed to us interesting to adapt some morphologies of Thom's catastrophe theory to some Jung's notions. Thus, we showed that the swallowtail, which is one of these morphologies, was able to describe geometrically the structural organisation of the psyche according to Jung, with its collective unconscious, personal unconscious and conscious. Moreover, we have correlated this morphology with Jung's evolutive processes like individualization and individuation. These comparisons incited us to think that some morphologies of Thom's catastrophe theory are the geometrical dealing of Jung's archetypes.

  10. Diffraction operators in paraxial approach

    NASA Astrophysics Data System (ADS)

    Lasso, William; Navas, Marianela; Añez, Liz; Urdaneta, Romer; Díaz, Leonardo; Torres, César O.

    2014-07-01

    Nowadays, research in the field of science education points to the creation of alternative ways of teaching contents encouraging the development of more elaborate reasoning, where a high degree of abstraction and generalization of scientific knowledge prevails. On that subject, this research shows a didactic alternative proposal for the construction of Fresnel and Fraunhoffer diffraction concepts applying the Fourier transform technique in the study of electromagnetic waves propagation in free space. Curvature transparency and Fourier sphere operators in paraxial approximation are used in order to make the usual laborious mathematical approach easier. The main result shows that the composition of optic metaxial operators results in the discovery of a simpler way out of the standard electromagnetic wave propagation in free space between a transmitter and a receptor separated from a given distance. This allows to state that the didactic proposal shown encourages the construction of Fresnel and Fraunhoffer diffraction concepts in a more effective and easier way than the traditional teaching.

  11. New approaches to hydrogen storage.

    PubMed

    Graetz, Jason

    2009-01-01

    The emergence of a Hydrogen Economy will require the development of new media capable of safely storing hydrogen in a compact and light weight package. Metal hydrides and complex hydrides, where hydrogen is chemically bonded to the metal atoms in the bulk, offer some hope of overcoming the challenges associated with hydrogen storage. The objective is to find a material with a high volumetric and gravimetric hydrogen density that can also meet the unique demands of a low temperature automotive fuel cell. Currently, there is considerable effort to develop new materials with tunable thermodynamic and kinetic properties. This tutorial review provides an overview of the different types of metal hydrides and complex hydrides being investigated for on-board (reversible) and off-board (non-reversible) hydrogen storage along with a few new approaches to improving the hydrogenation-dehydrogenation properties.

  12. Photonics approach to traffic signs

    NASA Astrophysics Data System (ADS)

    Litwin, Dariusz; Galas, Jacek; CzyŻewski, Adam; Rymsza, Barbara; Kornalewski, Leszek; Kryszczyński, Tadeusz; Mikucki, Jerzy; Wikliński, Piotr; Daszkiewicz, Marek; Malasek, Jacek

    2016-12-01

    The automotive industry has been always a driving force for all economies. Despite of its beneficial meaning to every society it brings also many issues including wide area of road safety. The latter has been enforced by the increasing number of cars and the dynamic development of the traffic as a whole. Road signs and traffic lights are crucial in context of good traffic arrangement and its fluency. Traffic designers are used to treat horizontal road signs independently of vertical signs. However, modern light sources and growing flexibility in shaping optical systems create opportunity to design more advanced and smart solutions. In this paper we present an innovative, multidisciplinary approach that consists in tight interdependence of different traffic signals. We describe new optical systems together with their influence on the perception of the road user. The analysis includes maintenance and visibility in different weather conditions. A special attention has been focused on intersections of complex geometry.

  13. Automated Approaches to RFI Flagging

    NASA Astrophysics Data System (ADS)

    Garimella, Karthik; Momjian, Emmanuel

    2017-01-01

    It is known that Radio Frequency Interference (RFI) is a major issue in centimeter wavelength radio astronomy. Radio astronomy software packages include tools to excise RFI; both manual and automated utilizing the visibilities (the uv data). Here we present results on an automated RFI flagging approach that utilizes a uv-grid, which is the intermediate product when converting uv data points to an image. It is a well known fact that any signal that appears widespread in a given domain (e.g., image domain) is compact in the Fourier domain (uv-grid domain), i.e., RFI sources that appear as large scale structures (e.g., stripes) in images can be located and flagged using the uv-grid data set. We developed several automated uv-grid based flagging algorithms to detect and excise RFI. These algorithms will be discussed, and results of applying them to measurement sets will be presented.

  14. LED instrument approach instruction display

    NASA Technical Reports Server (NTRS)

    Meredith, B. D.; Kelly, W. L., IV; Crouch, R. K.

    1979-01-01

    A display employing light emitting diodes (LED's) was developed to demonstrate the feasibility of such displays for presenting landing and navigation information to reduce the workload of general aviation pilots during IFR flight. The display consists of a paper tape reader, digital memory, control electronics, digital latches, and LED alphanumeric displays. A presentable digital countdown clock-timer is included as part of the system to provide a convenient means of monitoring time intervals for precise flight navigation. The system is a limited capability prototype assembled to test pilot reaction to such a device under simulated IFR operation. Pilot opinion indicates that the display is helpful in reducing the IFR pilots workload when used with a runway approach plate. However, the development of a compact, low power second generation display was recommended which could present several instructions simultaneously and provide information update capability. A microprocessor-based display could fulfill these requirements.

  15. Emerging Approaches in Predictive Toxicology

    PubMed Central

    Zhang, Luoping; McHale, Cliona M.; Greene, Nigel; Snyder, Ronald D.; Rich, Ivan N.; Aardema, Marilyn J.; Roy, Shambhu; Pfuhler, Stefan; Venkatactahalam, Sundaresan

    2016-01-01

    Predictive toxicology plays an important role in the assessment of toxicity of chemicals and the drug development process. While there are several well-established in vitro and in vivo assays that are suitable for predictive toxicology, recent advances in high-throughput analytical technologies and model systems are expected to have a major impact on the field of predictive toxicology. This commentary provides an overview of the state of the current science and a brief discussion on future perspectives for the field of predictive toxicology for human toxicity. Computational models for predictive toxicology, needs for further refinement and obstacles to expand computational models to include additional classes of chemical compounds are highlighted. Functional and comparative genomics approaches in predictive toxicology are discussed with an emphasis on successful utilization of recently developed model systems for high-throughput analysis. The advantages of three-dimensional model systems and stem cells and their use in predictive toxicology testing are also described. PMID:25044351

  16. Nationally Consistent Environmental Justice Screening Approaches

    EPA Pesticide Factsheets

    This report discusses screening approaches through the lens of the Agency's Environmental Justice Strategic Enforcement Tool (EJSEAT), in particular, and how such approaches might better identify areas of concern.

  17. A New Approach To Teaching Dimensional Analysis.

    ERIC Educational Resources Information Center

    Churchill, Stuart W.

    1997-01-01

    Explains an approach to teaching dimensional analysis that differs slightly from the traditional approach. The difference lies in the novelty of exposition in the presentation and interpretation of dimensional analysis as a speculative process. (DDR)

  18. Exhaustible Resource Depletion: A Modified Graphical Approach.

    ERIC Educational Resources Information Center

    Tisato, Peter

    1995-01-01

    Presents a graphical analysis of the exhaustible resource depletion problem. Applies Hotelling's "r percent rule" as a new approach that operates in an "N"-period context. Includes two figures illustrating the approach. (CFR)

  19. Another Approach to Generalizing the Mean

    ERIC Educational Resources Information Center

    Matejas, J.; Bahovec, V.

    2008-01-01

    This article presents a new approach to generalizing the definition of means. By this approach we easily obtain generalized means which are quite different from standard arithmetic, geometric and harmonic means.

  20. Validation of Modeling Flow Approaching Navigation Locks

    DTIC Science & Technology

    2013-08-01

    instrumentation, direction vernier . ........................................................................ 8  Figure 11. Plan A lock approach, upstream approach...13-9 8 Figure 9. Tools and instrumentation, bracket attached to rail. Figure 10. Tools and instrumentation, direction vernier . Numerical model

  1. C2 Approach: Agility, Autonomy (Briefing Charts)

    DTIC Science & Technology

    2015-04-01

    interdependent  entities  • Thus, the most  network  enabled approach is not always the most  appropriate • Rather, the most appropriate approach will be a function...that can  cascade  within individual  networks   and across  network  boundaries • Appreciate that C2 is not an end unto itself but needs to be  considered...Collaborative C2 Approach Coordinated C2 Approach De-Conflicted C2 Approach Conflicted C2 Approach Edge C2 Approach 8 Network  Enabled C2 Approaches     Source

  2. A Zen Approach to Volunteer Management.

    ERIC Educational Resources Information Center

    Barnett, Michael L.; Cahill, Gloria

    2002-01-01

    New York University's Zen approach to community service focuses on the principles of mindfulness, awareness, compassion, and engagement in the present moment. It enables a more holistic approach to the measurement of volunteer management objectives. (SK)

  3. Three Approaches to Stress Management for Children.

    ERIC Educational Resources Information Center

    Angus, Samuel F.

    1989-01-01

    Describes guided fantasy, yoga and autogenic phrases and thermal feedback as approaches to helping children manage stress. Provides guidelines for the use of these methods, followed by descriptions of each approach. (BH)

  4. Molecular approaches to fish vaccines

    USGS Publications Warehouse

    Winton, J.R.

    1998-01-01

    For more than 50 years, researchers have tested a variety of killed, attenuated, and subunit preparations for control offish diseases. The earliest fish vaccines used killed preparations containing whole bacteria, viruses, or parasites and today, several bacterins have become commercially successful with more expected as improved delivery systems and adjuvants are realized. Live, attenuated vaccines have been developed by serial passage of a pathogen in culture or by using naturally occurring mutants and cross-reacting strains. These generally offer excellent protection and are cost-effective, but concerns about residual virulence or their effects on other aquatic species make them difficult candidates for licensing. In recent years, the tools of molecular biology have been applied to construction of a variety of recombinant, engineered, or subunit vaccines for fish. Among the approaches to be discussed are: attenuated strains of viruses and bacteria created by deletion of specific genes associated with virulence, in vitro synthesis of protective antigens from genes cloned into E. coli or baculovirus expression systems, chemical synthesis of peptides that represent protective epitopes, and direct immunization with DNA coding for protective antigens. Preparations representing each of these approaches have been tested in laboratory or field trials with various results and such vaccines promise to be safe and relatively inexpensive if they are able to provide protection when delivered by immersion. A significant advantage of genetically engineered vaccines is the ability to construct multivalent preparations that can protect fish against several pathogens or different strains of the same pathogen. While many of these novel vaccine strategies have been effective at stimulating specific immunity in the laboratory, more work is needed to develop better delivery systems and to overcome potential regulatory concerns.

  5. Comprehensive approach to sarcopenia treatment.

    PubMed

    Wakabayashi, Hidetaka; Sakuma, Kunihiro

    2014-05-01

    Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life, and death. Primary sarcopenia is considered to be age-related when no other cause is evident, other than ageing itself. Secondary sarcopenia should be considered when one or more other causes are evident, such as activity-, disease-, or nutrition-related sarcopenia. In this narrative review that focused on human studies, we summarize the pharmaceutical therapies (testosterone, dehydroepiandrosterone, estrogen, growth hormone, ghrelin, vitamin D, angiotensin converting enzyme inhibitor, and eicosapentaenoic acid) and nonpharmaceutical therapies (resistance training, protein and amino acid supplementation, and non-smoking) for counteracting primary sarcopenia. Testosterone and growth hormone improve muscle mass and muscle strength, but have several side effects. Although there are some intriguing pharmaceutical therapies to combat sarcopenia, resistance training combined with supplements containing amino acids are the most effective for preventing and treating age-related muscle wasting and weakness. The etiology of sarcopenia in the elderly is multi-factorial. Patients with disuse syndrome and deconditioning often complicate the diagnosis, of not only activity-related sarcopenia, but also age-, disease-, and nutrition-related sarcopenia. In these cases a comprehensive approach to sarcopenia treatment should include pharmaceutical therapies for age-related sarcopenia and comorbid chronic diseases, resistance training, early ambulation, nutrition management, protein and amino acid supplementation, and non-smoking. The effect of pharmaceutical therapies for sarcopenia can be enhanced by this comprehensive approach. Future research on pharmaceutical therapies for counteracting sarcopenia should consider non-pharmaceutical therapies and also the causes of sarcopenia.

  6. A systematic approach to an organization's sustainability.

    PubMed

    Schalock, Robert L; Verdugo, Miguel; Lee, Tim

    2016-06-01

    This article integrates the concepts of sustainability and quality improvement into a systematic approach to an organization's sustainability. The article: (a) presents a literature-based model that incorporates the factors that drive an organization's sustainability; (b) describes how sustainability is operationalized through a systematic approach to quality improvement; (c) discusses the advantages of a systematic approach to sustainability; and (d) shares with the reader literature and experientially-based lessons learned about the approach.

  7. [Orbitozygomatic approaches to the skull base].

    PubMed

    Cherekaev, V A; Gol'bin, D A; Belov, A I; Radchenkov, N S; Lasunin, N V; Vinokurov, A G

    2015-01-01

    The paper is written in the lecture format and dedicated to one of the main basal approaches, the orbitozygomatic approach, that has been widely used by neurosurgeons for several decades. The authors describe the historical background of the approach development and the surgical technique features and also analyze the published data about application of the orbitozygomatic approach in surgery for skull base tumors and cerebral aneurysms.

  8. Larvae, Ladies and Learning: The Project Approach.

    ERIC Educational Resources Information Center

    Whitham, Laurel; Killoran, Isabel

    2003-01-01

    Describes the Project Approach and how it was used in a Grade 1 exploration of Painted Lady butterflies in Ontario, Canada. Outlines the students' experience with the project and examines the compatibility of the Project Approach with the Ontario Science and Technology Curriculum document. Maintains that the Project Approach supports and…

  9. 10 CFR 830.7 - Graded approach.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Graded approach. 830.7 Section 830.7 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.7 Graded approach. Where appropriate, a contractor must use a graded approach to implement the requirements of this part, document the basis of the graded...

  10. Materiality in a Practice-Based Approach

    ERIC Educational Resources Information Center

    Svabo, Connie

    2009-01-01

    Purpose: The paper aims to provide an overview of the vocabulary for materiality which is used by practice-based approaches to organizational knowing. Design/methodology/approach: The overview is theoretically generated and is based on the anthology Knowing in Organizations: A Practice-based Approach edited by Nicolini, Gherardi and Yanow. The…

  11. A Nonviolent Approach to Social Justice Education

    ERIC Educational Resources Information Center

    Wang, Hongyu

    2013-01-01

    This article advocates a nonviolent approach to social justice education. First, social justice education literature is reviewed, and two contrasting and influential approaches--critical theory and poststructural theory--are the focus of critical analysis. A nonviolent approach is proposed as an alternative. Second, the notion of social justice is…

  12. 10 CFR 830.7 - Graded approach.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Graded approach. 830.7 Section 830.7 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.7 Graded approach. Where appropriate, a contractor must use a graded approach to implement the requirements of this part, document the basis of the graded...

  13. 10 CFR 830.7 - Graded approach.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Graded approach. 830.7 Section 830.7 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.7 Graded approach. Where appropriate, a contractor must use a graded approach to implement the requirements of this part, document the basis of the graded...

  14. 10 CFR 830.7 - Graded approach.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Graded approach. 830.7 Section 830.7 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.7 Graded approach. Where appropriate, a contractor must use a graded approach to implement the requirements of this part, document the basis of the graded...

  15. 10 CFR 830.7 - Graded approach.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Graded approach. 830.7 Section 830.7 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.7 Graded approach. Where appropriate, a contractor must use a graded approach to implement the requirements of this part, document the basis of the graded...

  16. Preferences for Three Theoretically Derived Counseling Approaches

    ERIC Educational Resources Information Center

    Holen, Michael C.; Kinsey, William M.

    1975-01-01

    This study examined differences in potential-client preference and believed effectiveness for counseling approaches. Analyses of responses to randomly ordered same-client, same-problem tapes of each approach indicated that the behavioral approach was significantly more highly preferred and believed more effective than either the client-centered or…

  17. The Large Context Problem (LCP) Approach

    ERIC Educational Resources Information Center

    Stinner, Arthur

    2006-01-01

    This article traces the development of a contextual approach to the teaching of science (physics) subsequently called the Large Context Problem (LCP) approach. This approach is based on the general observation that learning could be well motivated by a context with one unifying central idea capable of capturing the imagination of the students. The…

  18. Edith Kaplan and the Boston Process Approach.

    PubMed

    Libon, David J; Swenson, Rodney; Ashendorf, Lee; Bauer, Russell M; Bowers, Dawn

    2013-01-01

    The history including some of the intellectual origins of the Boston Process Approach and some misconceptions about the Boston Process Approach are reviewed. The influence of Gestalt psychology and Edith Kaplan's principal collaborators regarding the development of the Boston Process Approach is discussed.

  19. Exploring Academics' Approaches to Managing Team Assessment

    ERIC Educational Resources Information Center

    Augar, Naomi; Woodley, Carolyn J.; Whitefield, Despina; Winchester, Maxwell

    2016-01-01

    Purpose: The purpose of this paper is to develop an understanding of academics' approaches to managing team assessment at an Australian University with a view to informing policy development and assessment design. Design/methodology/approach: The research was conducted using a single exploratory case study approach focussing on the team assessment…

  20. Apprehending ganglioside diversity: a comprehensive methodological approach[S

    PubMed Central

    Masson, Elodie A. Y.; Sibille, Estelle; Martine, Lucy; Chaux-Picquet, Fanny; Bretillon, Lionel; Berdeaux, Olivier

    2015-01-01

    Gangliosides (GGs) make a wide family of glycosphingolipids ubiquitously expressed in mammalian tissues and particularly abundant in the brain and nervous system. They exhibit a huge diversity due to structural variations in both their oligosaccharidic chain and ceramide moiety, which represent a real analytical challenge. Since their discovery in the 1940s, methods have persistently improved until the emergence of LC/MS, which offers a high level of specificity and sensitivity and is suitable with high-throughput profiling studies. We describe here a comprehensive approach relying on various techniques and aiming at fully characterizing GGs in biological samples. First, total GG content was determined by a biochemical assay. Second, GG class composition was assessed by high-performance thin-layer chromatography followed by colorimetric revelation. Then, ceramide types of GG classes were identified, and their relative quantification was performed thanks to the development of a powerful and reliable LC/MS method. Finally, ceramides were structurally characterized, and minor and less common GG classes were identified using high-resolution MS. These methods were applied to the rat retina to provide an exhaustive description of its GG composition, giving the base for a better understanding of the precise roles of GGs in this tissue. PMID:26142958

  1. [Approach to juxtarenal inflammatory aneurysms].

    PubMed

    Scuro, A; Barzaghi, M E; Griso, A; Ferrari Ruffino, S; Kontothanassis, D; Mirandola, M; Leonardi, G; D'Agata, M

    2004-01-01

    The incidence of inflammatory abdominal aortic aneurysm (IAAA) in a late review of the literature is estimated about 2-15% overall aortic aneurysms. In our data this type of aneurysm is 3.6 overall aortic aneurysms treated. In the majority of the cases, IAAA is juxtarenal or infrarenal. Ethiopathogenesis of IAAA till today is not certain. Recent hypothesis on IAAA attribute the same ethiopathogenesis in both atherosclerotic and inflammatory aneurysm. The interaction of genetic, environmental and infective factors should be able to determine an autoimmune inflammatory reaction of variable severity. 80% of the patients suffering from IAAA present abdominal or lumbar pain, loss of weight and increase of the RC sedimentation velocity. The IAAA's natural history goes to rupture. Entrapment of nearstanding organs totally involved in the fibrotic process is the most frequent complication. Usually there is a compression of the ureter and the duodenum with consequenced hydroureteronephrosis and bowel obstruction. Preoperative diagnosis is possible; CT scan and MRI guarantee and accuracy about 90%. Intraoperatively the external wall of IAAA appears whitish and translucent and always there are tenacious adhesion given by the avventital wounds inflammation. Confirm is given by the histological examination of the aneurysmatic wall and peravventitial tissues. Our experience and a late review of the literature concorde that surgical indication for the treatment of IAAA is the same for the atherosclerotic one. This conviction is supported by the fact that the diagnostic methodical evolution and the improvement in mininvasive surgical technique lowered perioperating morbility and mortaliy. We prefer, according with many authors, retroperitoneal approach to juxtarenal IAAA, instead of standardized transperitoneal access with xifo-pubical or transversal under costal incision. This approach offers some advantages as easier exposition of aorta, whose postero-lateral wall is hardly ever

  2. Some approaches to polaron theory

    NASA Astrophysics Data System (ADS)

    Bogolubov, N. N.; Bogolubov, N. N.

    1985-11-01

    Here, in our approximation of polaron theory, we examine the importance of introducing the T product, which turn out to be a very convenient theoretical approach for the calculation of thermodynamical averages. We focus attention on the investigation of the so-called linear polaron Hamiltonian and present in detail the calculation of the correlation function, spectral function, and Green function for such a linear system. It is shown that the linear polaron Hamiltonian provides an exactly solvable model of our system, and the result obtained with this approach holds true for an arbitrary coupling constant which describes the strength of interaction between the electron and the lattice vibrations. Then, with the help of a variational technique, we show the possibility of reducing the real polaron Hamiltonian to a socalled trial or approximate linear model Hamiltonian. We also consider the exact calculation of free energy with a special technique that reduces calculations with the help of the T product, which, in our opinion, works much better and is easier than other analogous considerations, for example, the path-integral or Feynman-integral method.(1,2) Here we furthermore recall our own work,(4) where it was shown that the results of Refs. 7 and 8 concerning the impedance calculation in the polaron model may be obtained directly without the use of the path-integral method. The study of the polaron system's thermodynamics is carried out by us in the framework of the functional method. A calculation of the free energy and the momentum distribution function is proposed. Note also that the polaron systems with strong coupling(9) proved to be useful in different quantum field models in connection with the construction of dynamical models of composite particles. A rigorous solution of the special strong-coupling polaron problem, describing the interaction of a nonrelativistic particle with a quantum field, was given by Bogolubov.(3) The works of Tavkhelidze, Fedyanin

  3. Computational Approaches to Vestibular Research

    NASA Technical Reports Server (NTRS)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and

  4. Batch Scheduling a Fresh Approach

    NASA Technical Reports Server (NTRS)

    Cardo, Nicholas P.; Woodrow, Thomas (Technical Monitor)

    1994-01-01

    The Network Queueing System (NQS) was designed to schedule jobs based on limits within queues. As systems obtain more memory, the number of queues increased to take advantage of the added memory resource. The problem now becomes too many queues. Having a large number of queues provides users with the capability to gain an unfair advantage over other users by tailoring their job to fit in an empty queue. Additionally, the large number of queues becomes confusing to the user community. The High Speed Processors group at the Numerical Aerodynamics Simulation (NAS) Facility at NASA Ames Research Center developed a new approach to batch job scheduling. This new method reduces the number of queues required by eliminating the need for queues based on resource limits. The scheduler examines each request for necessary resources before initiating the job. Also additional user limits at the complex level were added to provide a fairness to all users. Additional tools which include user job reordering are under development to work with the new scheduler. This paper discusses the objectives, design and implementation results of this new scheduler

  5. Cystic Lung Diseases: Algorithmic Approach.

    PubMed

    Raoof, Suhail; Bondalapati, Praveen; Vydyula, Ravikanth; Ryu, Jay H; Gupta, Nishant; Raoof, Sabiha; Galvin, Jeff; Rosen, Mark J; Lynch, David; Travis, William; Mehta, Sanjeev; Lazzaro, Richard; Naidich, David

    2016-10-01

    Cysts are commonly seen on CT scans of the lungs, and diagnosis can be challenging. Clinical and radiographic features combined with a multidisciplinary approach may help differentiate among various disease entities, allowing correct diagnosis. It is important to distinguish cysts from cavities because they each have distinct etiologies and associated clinical disorders. Conditions such as emphysema, and cystic bronchiectasis may also mimic cystic disease. A simplified classification of cysts is proposed. Cysts can occur in greater profusion in the subpleural areas, when they typically represent paraseptal emphysema, bullae, or honeycombing. Cysts that are present in the lung parenchyma but away from subpleural areas may be present without any other abnormalities on high-resolution CT scans. These are further categorized into solitary or multifocal/diffuse cysts. Solitary cysts may be incidentally discovered and may be an age related phenomenon or may be a remnant of prior trauma or infection. Multifocal/diffuse cysts can occur with lymphoid interstitial pneumonia, Birt-Hogg-Dubé syndrome, tracheobronchial papillomatosis, or primary and metastatic cancers. Multifocal/diffuse cysts may be associated with nodules (lymphoid interstitial pneumonia, light-chain deposition disease, amyloidosis, and Langerhans cell histiocytosis) or with ground-glass opacities (Pneumocystis jirovecii pneumonia and desquamative interstitial pneumonia). Using the results of the high-resolution CT scans as a starting point, and incorporating the patient's clinical history, physical examination, and laboratory findings, is likely to narrow the differential diagnosis of cystic lesions considerably.

  6. Approach to infected skin ulcers

    PubMed Central

    Frank, Christopher; Bayoumi, Imaan; Westendorp, Claire

    2005-01-01

    OBJECTIVE To review the diagnosis and management of infected chronic skin ulcers. SOURCES OF INFORMATION Cochrane database, MEDLINE, and Google were searched for clinical practice guidelines (CPGs) for wound care. Most recommendations found in the CPGs had level II or III evidence. Expert and consensus opinion from the Canadian Chronic Wound Advisory Board and the International Wound Bed Preparation Advisory Board were also used. MAIN MESSAGE Bacteria in skin ulcers act along a continuum from contamination through colonization and critical colonization to infection. Critical colonization is not always associated with overt signs of infection but can result in failure to heal, poor-quality granulation tissue, increased wound friability, and increased drainage. Good-quality swab samples should be an adjunct to clinical acumen, not a primary strategy for diagnosis. Iodine and silver-based dressings, topical antibiotics, and systemic antibiotics can be helpful. CONCLUSION Diagnosis of chronic wound infection is based on clinical signs and a holistic approach to patients. More research into assessment and treatment of skin ulcer infection is needed. PMID:16250422

  7. Protein Solubilization: A Novel Approach

    PubMed Central

    Johnson, David H.; Wilson, W. William; DeLucas, Lawrence J.

    2014-01-01

    Formulation development presents significant challenges with respect to protein therapeutics. One component of these challenges is to attain high protein solubility (> 50 mg/ml for immunoglobulins) with minimal aggregation. Protein-protein interactions contribute to aggregation and the integral sum of these interactions can be quantified by a thermodynamic parameter known as the osmotic second virial coefficient (B-value). The method presented here utilizes high-throughput measurement of B-values to identify the influence of additives on protein-protein interactions. The experiment design uses three tiers of screens to arrive at final solution conditions that improve protein solubility. The first screen identifies individual additives that reduce protein interactions. A second set of B-values are then measured for different combinations of these additives via an incomplete factorial screen. Results from the incomplete factorial screen are used to train an artificial neural network (ANN). The “trained” ANN enables predictions of B-values for more than 4,000 formulations that include additive combinations not previously experimentally measured. Validation steps are incorporated throughout the screening process to ensure that 1) the protein’s thermal and aggregation stability characteristics are not reduced and 2) the artificial neural network predictive model is accurate. The ability of this approach to reduce aggregation and increase solubility is demonstrated using an IgG protein supplied by Minerva Biotechnologies, Inc. PMID:25270058

  8. A selectionist approach to reinforcement.

    PubMed Central

    Donahoe, J W; Burgos, J E; Palmer, D C

    1993-01-01

    We describe a principle of reinforcement that draws upon experimental analyses of both behavior and the neurosciences. Some of the implications of this principle for the interpretation of behavior are explored using computer simulations of adaptive neural networks. The simulations indicate that a single reinforcement principle, implemented in a biologically plausible neural network, is competent to produce as its cumulative product networks that can mediate a substantial number of the phenomena generated by respondent and operant contingencies. These include acquisition, extinction, reacquisition, conditioned reinforcement, and stimulus-control phenomena such as blocking and stimulus discrimination. The characteristics of the environment-behavior relations selected by the action of reinforcement on the connectivity of the network are consistent with behavior-analytic formulations: Operants are not elicited but, instead, the network permits them to be guided by the environment. Moreover, the guidance of behavior is context dependent, with the pathways activated by a stimulus determined in part by what other stimuli are acting on the network at that moment. In keeping with a selectionist approach to complexity, the cumulative effects of relatively simple reinforcement processes give promise of simulating the complex behavior of living organisms when acting upon adaptive neural networks. PMID:8354965

  9. Pharmacosynthetics: Reimagining the pharmacogenetic approach

    PubMed Central

    Farrell, Martilias S.; Roth, Bryan L.

    2012-01-01

    Pharmacology, in its broadest interpretation, is defined as the study of the interaction between physiological entities and drugs. In modern neuropsychopharmacology, this interaction is viewed as the drug itself on one side and signal transducer (receptor), the signal transduction cascade (effector proteins, second messengers), the cellular response (transcriptional regulation, activity modulation), the organ response (brain circuitry modulation), and, finally, the whole organism response (behavior) on the other. In other words, pharmacology has structured itself around the idea that the exogenous molecule (the drug) encodes a “signal” leading to everything on the other side including, in extreme renditions, a physiological response. The inference is that engaging a particular signal transduction pathway in a defined cell type leads inexorably to a prototypic physiological response. Thus, for instance, serotonergic activation of 5-HT2A receptors in rat aortic smooth muscle cells leads to an increase in intracellular Ca++ (via IP3 release) and smooth muscle contraction (Roth et al., 1986). Here, we suggest that the invention of synthetic ligand – GPCR pairs (aka DREADDs, RASSLS, ‘pharmacogenetics’) permits the study of pharmacology using a shifted equation: more of the signal transduction elements moved to the left and, subsequently, under experimental control. For the purposes of disambiguation and to clarify this new interpretation as a creation of pharmacological manipulation, we present the term pharmacosynthetics to describe what has heretofore been called pharmacogenetics or chemicogenetics. This review discusses this new interpretation and reviews recent applications of the technology and considerations of the approach. PMID:23063887

  10. The Wonder Approach to learning

    PubMed Central

    L’Ecuyer, Catherine

    2014-01-01

    Wonder, innate in the child, is an inner desire to learn that awaits reality in order to be awakened. Wonder is at the origin of reality-based consciousness, thus of learning. The scope of wonder, which occurs at a metaphysical level, is greater than that of curiosity. Unfortunate misinterpretations of neuroscience have led to false brain-based ideas in the field of education, all of these based on the scientifically wrong assumption that children’s learning depends on an enriched environment. These beliefs have re-enforced the Behaviorist Approach to education and to parenting and have contributed to deadening our children’s sense of wonder. We suggest wonder as the center of all motivation and action in the child. Wonder is what makes life genuinely personal. Beauty is what triggers wonder. Wonder attunes to beauty through sensitivity and is unfolded by secure attachment. When wonder, beauty, sensitivity and secure attachment are present, learning is meaningful. On the contrary, when there is no volitional dimension involved (no wonder), no end or meaning (no beauty) and no trusting predisposition (secure attachment), the rigid and limiting mechanical process of so-called learning through mere repetition become a deadening and alienating routine. This could be described as training, not as learning, because it does not contemplate the human being as a whole. PMID:25339882

  11. Chronobiological approaches to Alzheimer's disease.

    PubMed

    Stranahan, Alexis M

    2012-01-01

    Dynamic circadian rhythms contribute to memory formation, and the hormonal and neurochemical changes that follow circadian patterns are frequently dysregulated with aging. The effect of aging on circadian rhythms is a double-edged sword; on one hand, poor sleep quality compromises neuronal structure and function in regions that support cognition, and on the other hand, perturbation of central and peripheral oscillators changes the hormonal milieu, with consequences for neuroplasticity. In the current review, recent developments surrounding the circadian regulation of memory formation are described, with reference to how mechanisms that support temporal coding might change with advancing age. The cognitive consequences of changes in sleep patterns are also discussed. New roles for the circadian clock genes period-1, period-2, and bmal1 in memory formation are discussed in the context of age-related cognitive decline. The potential for chronobiological approaches to the treatment and prevention of Alzheimer's disease merits further exploration from a pharmacotherapeutic perspective, as the timing of drug delivery could potentiate or diminish treatment efficacy.

  12. Approaches towards endogenous pancreatic regeneration.

    PubMed

    Banerjee, Meenal; Kanitkar, Meghana; Bhonde, Ramesh R

    2005-01-01

    The phenomenon of pancreatic regeneration in mammals has been well documented. It has been shown that pancreatic tissue is able to regenerate in several species of mammal after surgical insult. This tissue is also known to have the potential to maintain or increase its beta-cell mass in response to metabolic demands during pregnancy and obesity. Since deficiency in beta-cell mass is the hallmark of most forms of diabetes, it is worthwhile understanding pancreatic regeneration in the context of this disease. With this view in mind, this article aims to discuss the potential use in clinical strategies of knowledge that we obtained from studies carried out in animal models of diabetes. Approaches to achieve this goal involve the use of biomolecules, adult stem cells and gene therapy. Various molecules, such as glucagon-like peptide-1, beta-cellulin, nicotinamide, gastrin, epidermal growth factor-1 and thyroid hormone, play major roles in the initiation of endogenous islet regeneration in diabetes. The most accepted hypothesis is that these molecules stimulate islet precursor cells to undergo neogenesis or to induce replication of existing beta-cells, emphasizing the importance of pancreas-resident stem/progenitor cells in islet regeneration. Moreover, the potential of adult stem cell population from bone marrow, umbilical cord blood, liver, spleen, or amniotic membrane, is also discussed with regard to their potential to induce pancreatic regeneration.

  13. Our 2014 approach to mucormycosis.

    PubMed

    Tacke, Daniela; Koehler, Philipp; Markiefka, Birgid; Cornely, Oliver A

    2014-09-01

    Mucormycosis, previously termed as zygomycosis, is caused by fungi belonging to the order Mucorales and is a very severe disease in immunocompromised patients with an often unfavourable outcome. Given the high morbidity and mortality of mucormycosis, establishing a timely diagnosis followed by immediate treatment is of major importance. As randomised clinical trials are lacking, we present our current diagnostic and treatment pathways for mucormycosis in the immunocompromised host. Due to the difficulty to distinguish mucormycosis from other filamentous fungi, mucormycosis always has to be considered as differential diagnosis in predisposed patients. Diagnostic procedures comprise imaging, microscopy, culture and histopathology and need to be rigorously used. In patients with a high suspicion of mucormycosis, e.g. reversed halo sign on computed tomography scanning, our approach combines liposomal amphotericin B (LAmB) with surgical debridement. In light of the rapid deterioration and poor prognosis of these patients, we prefer a daily dose of LAmB of at least 5 mg kg(-1) despite nephrotoxicity. In patients with stable disease we switch to posaconazole 200 mg four times per day. In case of progression antifungal combination is an option.

  14. Hamiltonian approach to frame dragging

    NASA Astrophysics Data System (ADS)

    Epstein, Kenneth J.

    2008-07-01

    A Hamiltonian approach makes the phenomenon of frame dragging apparent “up front” from the appearance of the drag velocity in the Hamiltonian of a test particle in an arbitrary metric. Hamiltonian (1) uses the inhomogeneous force equation (4), which applies to non-geodesic motion as well as to geodesics. The Hamiltonian is not in manifestly covariant form, but is covariant because it is derived from Hamilton’s manifestly covariant scalar action principle. A distinction is made between manifest frame dragging such as that in the Kerr metric, and hidden frame dragging that can be made manifest by a coordinate transformation such as that applied to the Robertson-Walker metric in Sect. 2. In Sect. 3 a zone of repulsive gravity is found in the extreme Kerr metric. Section 4 treats frame dragging in special relativity as a manifestation of the equivalence principle in accelerated frames. It answers a question posed by Bell about how the Lorentz contraction can break a thread connecting two uniformly accelerated rocket ships. In Sect. 5 the form of the Hamiltonian facilitates the definition of gravitomagnetic and gravitoelectric potentials.

  15. Astronomy 2020: A Pragmatic Approach

    NASA Astrophysics Data System (ADS)

    Graham, M. J.

    2009-09-01

    In the cinema history of astronomy, we are currently at the stage of the Lumiere brothers with contemporary surveys providing short monochromatic time sequences of the sky. By the end of the next decade, however, panchromatic blockbusters will be commonplace and science will be predominantly driven by the objects that change in successive ``frames''. Web-scale computing resources will be required just to process the torrents of data events but the key to understanding them will be contextualisation --- linking together disparate (sets of) events and relating them to archival and supplementary data in a machine-comprehensible way. Much of the data mining and analysis of such data portfolios will be performed by proxy scientists --- intelligent agent avatars that represent an individual's particular research interests in high-dimension parameter spaces. Although this view might sound like science fiction, in this paper, I will review the technologies that will make it achievable. In particular, I will cover new approaches to web services that will be required to support these massive event streams, social networking techniques that will facilitate science and semantic technologies that will underpin everything.

  16. System approach to MEMS commercialization

    NASA Astrophysics Data System (ADS)

    Vaganov, Vladimir I.; Belov, Nickolai; in't Hout, Sebastiaan R.

    2003-04-01

    It is common to underestimate the challenges of integrating the at least four technologies in any MEMS product: the three technologies of any semiconductor device (electronics, packaging and testing) plus the MEMS microstructure. For some specific areas of application, for example for photonics, optics technology/components must also be integrated. While traditional semiconductor devices utilize standardized and inexpensive packaging and testing procedures and equipment, MEMS require custom solutions that introduce multiple physical domains, such as light in the case of photonics, directly to a potentially moving structure on the die. This heightened complexity coupled with nonstandard packaging, testing and other (optics) technologies has a dramatic impact on functionality, reliability and cost. Being developed and successfully proven for a period of about twenty-five years the System Approach to MEMS Commercialization is based on three major principles: A priori understanding of the interdependence of technologies integrated into MEMS products: micro-machining, IC technology, packaging, testing and other (optics) technologies. Parallel development or implementation of these technologies within the MEMS product. Redistribution of manufacturing complexity from individual to batch realm. Integrating packaging and testing and other (optics) components into the microstructure and including some of the testing and functional algorithms in the ASIC reduce cost by simplifying more expensive individual manufacturing steps. The overall results of redistribution complexity from individual manufacturing technologies into batch manufacturing technologies are dramatic cost reduction, performance and quality improvement and shorter time to market.

  17. Innovative approach towards understanding optics

    NASA Astrophysics Data System (ADS)

    Garg, Amit; Bharadwaj, Sadashiv Raj; Kumar, Raj; Shudhanshu, Avinash Kumar; Verma, Deepak Kumar

    2016-01-01

    Over the last few years, there has been a decline in the students’ interest towards Science and Optics. Use of technology in the form of various types of sensors and data acquisition systems has come as a saviour. Till date, manual routine tools and techniques are used to perform various experimental procedures in most of the science/optics laboratories in our country. The manual tools are cumbersome whereas the automated ones are costly. It does not enthuse young researchers towards the science laboratories. There is a need to develop applications which can be easily integrated, tailored at school and undergraduate level laboratories and are economical at the same time. Equipments with advanced technologies are available but they are uneconomical and have complicated working principle with a black box approach. The present work describes development of portable tools and applications which are user-friendly. This is being implemented using open-source physical computing platform based on a simple low cost microcontroller board and a development environment for writing software. The present paper reports the development of an automated spectrometer, an instrument used in almost all optics experiments at undergraduate level, and students’ response to this innovation. These tools will inspire young researchers towards science and facilitate development of advance low cost equipments making life easier for Indian as well as developing nations.

  18. New approaches to treating pain.

    PubMed

    Wolkerstorfer, Andrea; Handler, Norbert; Buschmann, Helmut

    2016-02-15

    Pain is the most common reason for patients seeking medical care resulting in an estimated world market for analgesics of more than USD 50 billion. Pain is a highly complex, heterogeneous and dynamic process characterized by specific patterns of phenotypic sensory neuronal change. Current treatment options for pain include opioids and non-opioid analgesics, acetaminophen and non-steroidal anti-inflammatory drugs and other drug classes such as antidepressants and anticonvulsants and a combination thereof. Novel approaches are focusing on the optimization of side-effect profiles of opioid based analgesics, the improvement of selectivity for specific opioid receptors, or by addressing molecular gateways implicated in pain. Promising candidates in development target various types of voltage-gated ion channels and receptors for capsaicin and analogs. Currently, after decades of pain research it has to be stated that the assessment, prevention and treatment of pain in industrialized countries as well as in low-income and middle-income countries are neither adequate nor equitable. Further research is needed so that specifically chronic pain control can be improved and individualized.

  19. A practical approach to fibromyalgia.

    PubMed

    Brecher, L S; Cymet, T C

    2001-04-01

    The term fibromyalgia refers to a collection of symptoms with no clear physiologic cause, but the symptoms together constitute a clearly recognizable and distinct pathologic entity. The diagnosis is made through the examiner's clinical observations. The differential diagnosis must include other somatic syndromes as well as disease entities, including hepatitis, hypothyroidism, diabetes mellitus, electrolyte imbalance, multiple sclerosis, and cancer. Diagnostic criteria serve as guidelines for diagnosis, not as absolute requirements. Treatment of fibromyalgia, which is an ongoing process, remains individualized, relying on a good physician-patient relationship. It is goal-oriented, directed at helping patients get restorative sleep, alleviating the somatic pains, keeping patients productive, and regulating schedules. It can be achieved through a goal-oriented agreement between patient and provider. Because fibromyalgia is chronic and may affect all areas of an individual's functioning, the physician needs to also evaluate the social support systems of patients with fibromyalgia. The approach to treatment should integrate patient education as well as non-pharmacologic and pharmacologic modalities. To keep patients well educated and involved in their healthcare, physicians should provide patients with adequate sources for reliable information.

  20. Nonstationary Approaches to Hydrologic Design

    NASA Astrophysics Data System (ADS)

    Vogel, Richard; Hecht, Jory; Read, Laura

    2014-05-01

    We introduce a generalized framework for evaluating the risk, reliability and return period of hydrologic events in a nonstationary world. A heteroscedastic regression model is introduced as an elegant and general framework for modeling trends in the mean and/or variance of hydrologic records using ordinary least squares regression methods. A regression approach to modeling trends has numerous advantages over other methods including: (1) ease of application, (2) considers linear or nonlinear trends, (3) graphical display of trends, (4) analytical estimate of the power of the trend test and prediction intervals associated with trend extrapolation. Traditional statements of risk, reliability and return periods which assume that the annual probability of a flood event remains constant throughout the project horizon are revised to include the impacts of trends in the mean and/or variance of hydrologic records. Our analyses reveal that in a nonstationary world, meaningful expressions of the likelihood of future hydrologic events are unlikely to result from knowledge of return periods whereas knowledge of system reliability over future planning horizons can effectively communicate the likelihood of future hydrologic events of interest.

  1. NASA's Approach to Software Assurance

    NASA Technical Reports Server (NTRS)

    Wetherholt, Martha

    2015-01-01

    NASA defines software assurance as: the planned and systematic set of activities that ensure conformance of software life cycle processes and products to requirements, standards, and procedures via quality, safety, reliability, and independent verification and validation. NASA's implementation of this approach to the quality, safety, reliability, security and verification and validation of software is brought together in one discipline, software assurance. Organizationally, NASA has software assurance at each NASA center, a Software Assurance Manager at NASA Headquarters, a Software Assurance Technical Fellow (currently the same person as the SA Manager), and an Independent Verification and Validation Organization with its own facility. An umbrella risk mitigation strategy for safety and mission success assurance of NASA's software, software assurance covers a wide area and is better structured to address the dynamic changes in how software is developed, used, and managed, as well as it's increasingly complex functionality. Being flexible, risk based, and prepared for challenges in software at NASA is essential, especially as much of our software is unique for each mission.

  2. Hyperprolactinemia: pathophysiology and therapeutic approach.

    PubMed

    Capozzi, Anna; Scambia, Giovanni; Pontecorvi, Alfredo; Lello, Stefano

    2015-07-01

    Prolactin (PRL) is a hormone, mainly secreted by lactotroph cells of the anterior pituitary gland. Recent studies have shown it may also be produced by many extrapituitary cells. Its well-recognized PRL plays an important role in lactation during pregnancy, but it is involved in other biological functions such as angiogenesis, immunoregulation and osmoregulation. Hyperprolactinemia is a typical condition producing reproductive dysfunction in both sexes, resulting in hypogonadism, infertility and galactorrhea. It may be also asymptomatic. Lactotroph adenomas (prolactinoma) is one of the most common cause of PRL excess, representing approximately 40% of all pituitary tumors. Several other conditions should be excluded before a clear diagnosis of hyperprolactinemia is made. Hyperprolactinemia may be secondary to pharmacological or pathological interruption of hypothalamic-pituitary dopaminergic pathways or idiopathic. Stress, renal failure or hypothyroidism are other frequent conditions to exclude in patients with hyperprolactinemia. We will review biochemical characteristics and physiological functions of that hormone. Clinical and pharmacological approach to hyperprolactinemia will also be discussed.

  3. Glioblastoma Multiforme: Novel Therapeutic Approaches

    PubMed Central

    Fialho, Arsenio M.; Salunkhe, Prabhakar; Manna, Sunil; Mahali, Sidharth; Chakrabarty, Ananda M.

    2012-01-01

    The current therapy for glioblastoma multiforme involves total surgical resection followed by combination of radiation therapy and temozolomide. Unfortunately, the efficacy for such current therapy is limited, and newer approaches are sorely needed to treat this deadly disease. We have recently described the isolation of bacterial proteins and peptides with anticancer activity. In phase I human clinical trials, one such peptide, p28, derived from a bacterial protein azurin, showed partial and complete regression of tumors in several patients among 15 advanced-stage cancer patients with refractory metastatic tumors where the tumors were no longer responsive to current conventional drugs. An azurin-like protein called Laz derived from Neisseria meningitides demonstrates efficient entry and high cytotoxicity towards glioblastoma cells. Laz differs from azurin in having an additional 39-amino-acid peptide called an H.8 epitope, which allows entry and high cytotoxicity towards glioblastoma cells. Since p28 has been shown to have very little toxicity and high anti-tumor activity in advanced-stage cancer patients, it will be worthwhile to explore the use of H.8-p28, H.8-azurin, and Laz in toxicity studies and glioblastoma therapy in preclinical and human clinical trials. PMID:22462021

  4. Natural approach to quantum dissipation

    NASA Astrophysics Data System (ADS)

    Taj, David; Öttinger, Hans Christian

    2015-12-01

    The dissipative dynamics of a quantum system weakly coupled to one or several reservoirs is usually described in terms of a Lindblad generator. The popularity of this approach is certainly due to the linear character of the latter. However, while such linearity finds justification from an underlying Hamiltonian evolution in some scaling limit, it does not rely on solid physical motivations at small but finite values of the coupling constants, where the generator is typically used for applications. The Markovian quantum master equations we propose are instead supported by very natural thermodynamic arguments. They themselves arise from Markovian master equations for the system and the environment which preserve factorized states and mean energy and generate entropy at a non-negative rate. The dissipative structure is driven by an entropic map, called modular, which introduces nonlinearity. The generated modular dynamical semigroup (MDS) guarantees for the positivity of the time evolved state the correct steady state properties, the positivity of the entropy production, and a positive Onsager matrix with symmetry relations arising from Green-Kubo formulas. We show that the celebrated Davies Lindblad generator, obtained through the Born and the secular approximations, generates a MDS. In doing so we also provide a nonlinear MDS which is supported by a weak coupling argument and is free from the limitations of the Davies generator.

  5. Repository Closure and Sealing Approach

    SciTech Connect

    A.T. Watkins

    2000-06-28

    The scope of this analysis will be to develop the conceptual design of the closure seals and their locations in the Subsurface Facilities. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the ''Monitored Geologic Repository Project Description Document'' (CRWMS M&O 1999b). The objective of this analysis will be to assist in providing a description for the Subsurface Facilities System Description Document, Section 2 and finally to document any conclusions reached in order to contribute and provide support to the SR. This analysis is at a conceptual level and is considered adequate to support the SR design. The final closure barriers and seals for the ventilation shafts, and the north and south ramps will require these openings to be permanently sealed to limit excessive air and water inflows and prevent human intrusion. The major tasks identified with closure in this analysis are: (1) Developing the overall subsurface seal layout and identifying design and operational interfaces for the Subsurface Facilities. (2) Summarizing the general site conditions and general rock characteristic with respect to seal location and describing the seal selected. (3) Identify seal construction materials, methodology of construction and strategic locations including design of the seal and plugs. (4) Discussing methods to prevent human intrusion.

  6. Deficient approaches to human neuroimaging

    PubMed Central

    Stelzer, Johannes; Lohmann, Gabriele; Mueller, Karsten; Buschmann, Tilo; Turner, Robert

    2014-01-01

    Functional magnetic resonance imaging (fMRI) is the workhorse of imaging-based human cognitive neuroscience. The use of fMRI is ever-increasing; within the last 4 years more fMRI studies have been published than in the previous 17 years. This large body of research has mainly focused on the functional localization of condition- or stimulus-dependent changes in the blood-oxygenation-level dependent signal. In recent years, however, many aspects of the commonly practiced analysis frameworks and methodologies have been critically reassessed. Here we summarize these critiques, providing an overview of the major conceptual and practical deficiencies in widely used brain-mapping approaches, and exemplify some of these issues by the use of imaging data and simulations. In particular, we discuss the inherent pitfalls and shortcomings of methodologies for statistical parametric mapping. Our critique emphasizes recent reports of excessively high numbers of both false positive and false negative findings in fMRI brain mapping. We outline our view regarding the broader scientific implications of these methodological considerations and briefly discuss possible solutions. PMID:25071503

  7. Comprehensive approach to diabetic nephropathy

    PubMed Central

    Satirapoj, Bancha; Adler, Sharon G.

    2014-01-01

    Diabetic nephropathy (DN) is a leading cause of mortality and morbidity in patients with diabetes. This complication reflects a complex pathophysiology, whereby various genetic and environmental factors determine susceptibility and progression to end-stage renal disease. DN should be considered in patients with type 1 diabetes for at least 10 years who have microalbuminuria and diabetic retinopathy, as well as in patients with type 1 or type 2 diabetes with macroalbuminuria in whom other causes for proteinuria are absent. DN may also present as a falling estimated glomerular filtration rate with albuminuria as a minor presenting feature, especially in patients taking renin–angiotensin–aldosterone system inhibitors (RAASi). The pathological characteristic features of disease are three major lesions: diffuse mesangial expansion, diffuse thickened glomerular basement membrane, and hyalinosis of arterioles. Functionally, however, the pathophysiology is reflected in dysfunction of the mesangium, the glomerular capillary wall, the tubulointerstitium, and the vasculature. For all diabetic patients, a comprehensive approach to management including glycemic and hypertensive control with RAASi combined with lipid control, dietary salt restriction, lowering of protein intake, increased physical activity, weight reduction, and smoking cessation can reduce the rate of progression of nephropathy and minimize the risk for cardiovascular events. This review focuses on the latest published data dealing with the mechanisms, diagnosis, and current treatment of DN. PMID:26894033

  8. Diagnostic approach to peripheral neuropathy

    PubMed Central

    Misra, Usha Kant; Kalita, Jayantee; Nair, Pradeep P.

    2008-01-01

    Peripheral neuropathy refers to disorders of the peripheral nervous system. They have numerous causes and diverse presentations; hence, a systematic and logical approach is needed for cost-effective diagnosis, especially of treatable neuropathies. A detailed history of symptoms, family and occupational history should be obtained. General and systemic examinations provide valuable clues. Neurological examinations investigating sensory, motor and autonomic signs help to define the topography and nature of neuropathy. Large fiber neuropathy manifests with the loss of joint position and vibration sense and sensory ataxia, whereas small fiber neuropathy manifests with the impairment of pain, temperature and autonomic functions. Electrodiagnostic (EDx) tests include sensory, motor nerve conduction, F response, H reflex and needle electromyography (EMG). EDx helps in documenting the extent of sensory motor deficits, categorizing demyelinating (prolonged terminal latency, slowing of nerve conduction velocity, dispersion and conduction block) and axonal (marginal slowing of nerve conduction and small compound muscle or sensory action potential and dennervation on EMG). Uniform demyelinating features are suggestive of hereditary demyelination, whereas difference between nerves and segments of the same nerve favor acquired demyelination. Finally, neuropathy is classified into mononeuropathy commonly due to entrapment or trauma; mononeuropathy multiplex commonly due to leprosy and vasculitis; and polyneuropathy due to systemic, metabolic or toxic etiology. Laboratory investigations are carried out as indicated and specialized tests such as biochemical, immunological, genetic studies, cerebrospinal fluid (CSF) examination and nerve biopsy are carried out in selected patients. Approximately 20% patients with neuropathy remain undiagnosed but the prognosis is not bad in them. PMID:19893645

  9. Diagnostic approach to Cushing disease.

    PubMed

    Gross, Bradley A; Mindea, Stefan A; Pick, Anthony J; Chandler, James P; Batjer, H Hunt

    2007-01-01

    In Cushing disease, a pituitary corticotroph neoplasm causes secondary adrenal hypercortisolism. This condition has known morbidity and mortality, underscoring the need for an efficient and accurate diagnostic approach. An 11 p.m. salivary cortisol level is a modern, simple initial screening tool for the diagnosis of Cushing syndrome. Confirmation with a 24-hour urinary free cortisol test and/or a low-dose dexamethasone suppression test may subsequently be performed. Patients with repeatedly equivocal results should be reevaluated after several months or undergo a corticotropin-releasing hormone (CRH) stimulation test following low-dose dexamethasone suppression to help rule out pseudo-Cushing states. The presence of low morning serum adrenocorticotropic hormone (ACTH) levels then distinguishes primary adrenal hypercortisolism from Cushing disease and the ectopic ACTH syndrome. Patients with moderate ACTH levels can undergo CRH stimulation testing to clarify the underlying disease because those with an ACTH-independent disorder have blunted subsequent ACTH levels. Once ACTH-dependent hypercortisolemia is detected, magnetic resonance (MR) imaging of the pituitary gland can be performed to detect a pituitary neoplasm. Normal or equivocal MR imaging results revealing small pituitary lesions should be followed up with inferior petrosal sinus sampling, a highly specific measure for the diagnosis of Cushing disease in experienced hands. If necessary, body imaging may be used in turn to detect sources of ectopic ACTH.

  10. IRB reliance: An informatics approach.

    PubMed

    Obeid, Jihad S; Alexander, Randall W; Gentilin, Stephanie M; White, Brigette; Turley, Christine B; Brady, Kathleen T; Lenert, Leslie A

    2016-04-01

    Multi-site Institutional Review Board (IRB) review of clinical research projects is an important but complex and time-consuming activity that is hampered by disparate non-interoperable computer systems for management of IRB applications. This paper describes our work toward harmonizing the workflow and data model of IRB applications through the development of a software-as-a-service shared-IRB platform for five institutions in South Carolina. Several commonalities and differences were recognized across institutions and a core data model that included the data elements necessary for IRB applications across all institutions was identified. We extended and modified the system to support collaborative reviews of IRB proposals within routine workflows of participating IRBs. Overall about 80% of IRB application content was harmonized across all institutions, establishing the foundation for a streamlined cooperative review and reliance. Since going live in 2011, 49 applications that underwent cooperative reviews over a three year period were approved, with the majority involving 2 out of 5 institutions. We believe this effort will inform future work on a common IRB data model that will allow interoperability through a federated approach for sharing IRB reviews and decisions with the goal of promoting reliance across institutions in the translational research community at large.

  11. Chemotherapy in Retinoblastoma: Current Approaches

    PubMed Central

    Yanık, Özge; Gündüz, Kaan; Yavuz, Kıvılcım; Taçyıldız, Nurdan; Ünal, Emel

    2015-01-01

    Retinoblastoma (RB) is the most common childhood malignant intraocular tumor. Although enucleation and external beam radiotherapy have been historically used, today the most commonly used eye-sparing approach is chemotherapy. Chemotherapy can be used in both intraocular and extraocular RB cases. Chemotherapeutic agents may be applied in different ways, including systemic, subconjunctival, intra-arterial and intravitreal routes. The main purposes of application of systemic therapy are to reduce the tumor size for local treatment (chemoreduction), or to reduce the risk of metastasis after enucleation surgery (adjuvant therapy). Intra-arterial chemotherapy with the current name “super-selective intra-arterial infusion therapy” could be applied as primary therapy in tumors confined to the retina or as a secondary method in tumor recurrence. The most important advantage of intra-arterial therapy is the prevention of systemic chemotherapy complications. Intravitreal chemotherapy is administered in the presence of persistent or recurrent vitreous seeding. The term “extraocular RB” includes orbital invasion and metastatic disease. Current treatment for orbital invasion is neoadjuvant chemotherapy followed by surgical enucleation and adjuvant chemotherapy and radiotherapy after surgery. In metastatic disease, regional lymph node involvement, distant metastases, and/or central nervous system (CNS) involvement may occur. Among them, CNS involvement has the worst prognosis, remaining at almost 100% mortality. In metastatic disease, high-dose salvage chemotherapy and autologous hematopoietic stem cell rescue therapy are the possible treatment options; radiotherapy could also be added to the protocol according to the side of involvement. PMID:27800245

  12. Standard Approaches to the Acetabulum Part 1: Kocher-Langenbeck Approach.

    PubMed

    Gänsslen, A; Grechenig, S; Nerlich, M; Müller, M

    2016-01-01

    Historically, standard approaches for surgical treatment of displaced acetabular fractures were the KocherLangenbeck approach, the ilioinguinal approach and the extended iliofemoral approach (12). Presently, several modifications of these approaches are accepted alternatives, especially anterior modifications based on the intrapelvic approach described by Hirvensalo (8). Single access approaches allowing visualization of one acetabular column are the posterior Kocher-Langenbeck approach and the anterior ilioinguinal approach (12) and the use of a single approach is favoured (9, 24). For more complex situations, in the 80s and 90s extended approaches (extended iliofemoral approach according to Letournel (12), its modification to Reinert (19) (Baltimore approach), and the Triradiate approach according to Mears (14)) were introduced. These approaches are presently rarely choosen due to the extensive soft tissue dissection and higher complication rates (28). Alternatively, the combination of an anterior and posterior standard approach was recommended (7, 21, 22) having the disadvantage of longer operating time and blood loss and showed no superior results compared to a single approach. The meta-analysis by Giannoudis et al. stated that 48,7% of patients were treated using the Kocher-Langenbeck approach, followed by 21,9% ilioinguinal approaches and 12,4% extended approaches (6). More recent data from the years 2005-2007, showed that anterior approaches are now predominantly used according to a higher number of acetabular fractures with anterior column involvement. Overall, more than 40% of all patients with acetabular fractures are still approached via the Kocher-Langenbeck approach (18). Therefore, the Kocher-Langenbeck approach is still a "working horse" in approaching displaced acetabular fractures. The Kocher-Langenbeck approach consists of two parts. In 1874 von Langenbeck described a longitudinal incision starting from above the greater sciatic notch to the

  13. 33 CFR 167.502 - In the approaches to Los Angeles-Long Beach: Western approach.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false In the approaches to Los Angeles-Long Beach: Western approach. 167.502 Section 167.502 Navigation and Navigable Waters COAST GUARD... approaches to Los Angeles-Long Beach: Western approach. (a) A separation zone is bounded by a line...

  14. 33 CFR 167.502 - In the approaches to Los Angeles-Long Beach: Western approach.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false In the approaches to Los Angeles-Long Beach: Western approach. 167.502 Section 167.502 Navigation and Navigable Waters COAST GUARD... approaches to Los Angeles-Long Beach: Western approach. (a) A separation zone is bounded by a line...

  15. 33 CFR 167.502 - In the approaches to Los Angeles-Long Beach: Western approach.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false In the approaches to Los Angeles-Long Beach: Western approach. 167.502 Section 167.502 Navigation and Navigable Waters COAST GUARD... approaches to Los Angeles-Long Beach: Western approach. (a) A separation zone is bounded by a line...

  16. 33 CFR 167.502 - In the approaches to Los Angeles-Long Beach: Western approach.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false In the approaches to Los Angeles-Long Beach: Western approach. 167.502 Section 167.502 Navigation and Navigable Waters COAST GUARD... approaches to Los Angeles-Long Beach: Western approach. (a) A separation zone is bounded by a line...

  17. 33 CFR 167.502 - In the approaches to Los Angeles-Long Beach: Western approach.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false In the approaches to Los Angeles-Long Beach: Western approach. 167.502 Section 167.502 Navigation and Navigable Waters COAST GUARD... approaches to Los Angeles-Long Beach: Western approach. (a) A separation zone is bounded by a line...

  18. 33 CFR 167.203 - In the approaches to Chesapeake Bay: Southern approach.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false In the approaches to Chesapeake Bay: Southern approach. 167.203 Section 167.203 Navigation and Navigable Waters COAST GUARD... approaches to Chesapeake Bay: Southern approach. (a) An inbound traffic lane is established...

  19. Phobos Sample Return: Next Approach

    NASA Astrophysics Data System (ADS)

    Zelenyi, Lev; Martynov, Maxim; Zakharov, Alexander; Korablev, Oleg; Ivanov, Alexey; Karabadzak, George

    The Martian moons still remain a mystery after numerous studies by Mars orbiting spacecraft. Their study cover three major topics related to (1) Solar system in general (formation and evolution, origin of planetary satellites, origin and evolution of life); (2) small bodies (captured asteroid, or remnants of Mars formation, or reaccreted Mars ejecta); (3) Mars (formation and evolution of Mars; Mars ejecta at the satellites). As reviewed by Galimov [2010] most of the above questions require the sample return from the Martian moon, while some (e.g. the characterization of the organic matter) could be also answered by in situ experiments. There is the possibility to obtain the sample of Mars material by sampling Phobos: following to Chappaz et al. [2012] a 200-g sample could contain 10-7 g of Mars surface material launched during the past 1 mln years, or 5*10-5 g of Mars material launched during the past 10 mln years, or 5*1010 individual particles from Mars, quantities suitable for accurate laboratory analyses. The studies of Phobos have been of high priority in the Russian program on planetary research for many years. Phobos-88 mission consisted of two spacecraft (Phobos-1, Phobos-2) and aimed the approach to Phobos at 50 m and remote studies, and also the release of small landers (long-living stations DAS). This mission implemented the program incompletely. It was returned information about the Martian environment and atmosphere. The next profect Phobos Sample Return (Phobos-Grunt) initially planned in early 2000 has been delayed several times owing to budget difficulties; the spacecraft failed to leave NEO in 2011. The recovery of the science goals of this mission and the delivery of the samples of Phobos to Earth remain of highest priority for Russian scientific community. The next Phobos SR mission named Boomerang was postponed following the ExoMars cooperation, but is considered the next in the line of planetary exploration, suitable for launch around 2022. A

  20. Approach to autism spectrum disorder

    PubMed Central

    Lee, Patrick F.; Thomas, Roger E.; Lee, Patricia A.

    2015-01-01

    Objective To review the diagnostic criteria for autism spectrum disorder (ASD) from the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V), and to develop an approach to managing ASD using the CanMEDS– Family Medicine (CanMEDS-FM) framework. Sources of information The DSM-V from the American Psychiatric Association, published in May 2013, provides new diagnostic criteria for ASD. The College of Family Physicians of Canada’s CanMEDS-FM framework provides a blueprint that can guide the complex management of ASD. We used data from the Centers for Disease Control and Prevention to determine the prevalence of ASD, and we used the comprehensive systematic review and meta-analysis completed by the UK National Institute for Health and Care Excellence for their guidelines on ASD to assess the evidence for more than 100 interventions. Main message The prevalence of ASD was 1 in 88 in 2008 in the United States according to data from the Centers for Disease Control and Prevention. The ASD classification in the fourth edition of the DSM included autism, Asperger syndrome, pervasive developmental disorder, and childhood disintegrative disorder. The new DSM-V revision incorporates all these disorders into one ASD umbrella term with different severity levels. The management of ASD is complex and requires a multidisciplinary team effort and continuity of care. The CanMEDS-FM roles provide a framework for management. Conclusion Family physicians are the key leaders of the multidisciplinary care team for ASD, and the CanMEDS-FM framework provides a comprehensive guide to help manage a child with ASD and to help the child’s family. PMID:25971758

  1. Personalized medicine approaches in epilepsy.

    PubMed

    Walker, L E; Mirza, N; Yip, V L M; Marson, A G; Pirmohamed, M

    2015-02-01

    Epilepsy affects 50 million persons worldwide, a third of whom continue to experience debilitating seizures despite optimum anti-epileptic drug (AED) treatment. Twelve-month remission from seizures is less likely in female patients, individuals aged 11-36 years and those with neurological insults and shorter time between first seizure and starting treatment. It has been found that the presence of multiple seizures prior to diagnosis is a risk factor for pharmacoresistance and is correlated with epilepsy type as well as intrinsic severity. The key role of neuroinflammation in the pathophysiology of resistant epilepsy is becoming clear. Our work in this area suggests that high-mobility group box 1 isoforms may be candidate biomarkers for treatment stratification and novel drug targets in epilepsy. Furthermore, transporter polymorphisms contributing to the intrinsic severity of epilepsy are providing robust neurobiological evidence on an emerging theory of drug resistance, which may also provide new insights into disease stratification. Some of the rare genetic epilepsies enable treatment stratification through testing for the causal mutation, for example SCN1A mutations in patients with Dravet's syndrome. Up to 50% of patients develop adverse reactions to AEDs which in turn affects tolerability and compliance. Immune-mediated hypersensitivity reactions to AED therapy, such as toxic epidermal necrolysis, are the most serious adverse reactions and have been associated with polymorphisms in the human leucocyte antigen (HLA) complex. Pharmacogenetic screening for HLA-B*15:02 in Asian populations can prevent carbamazepine-induced Stevens-Johnson syndrome. We have identified HLA-A*31:01 as a potential risk marker for all phenotypes of carbamazepine-induced hypersensitivity with applicability in European and other populations. In this review, we explore the currently available key stratification approaches to address the therapeutic challenges in epilepsy.

  2. Approaches to mitochondrial gene therapy.

    PubMed

    D'Souza, Gerard G M; Weissig, Volkmar

    2004-09-01

    Since their discovery during the end of the 80's the number of diseases found to be associated with defects in the mitochondrial genome has grown significantly. Organs affected by mutations in mitochondrial DNA (mtDNA) include in decreasing order of vulnerability the brain, skeletal muscle, heart, kidney and liver. Hence neuromuscular and neurodegenerative diseases represent the two largest groups of mtDNA diseases. Despite major advances in understanding mtDNA defects at the genetic and biochemical level, there is however no satisfactory treatment available to the vast majority of patients. This is largely due to the fact that most of these patients have respiratory chain defects, i.e. defects that involve the final common pathway of oxidative metabolism, making it impossible to bypass the defect by administering alternative metabolic carriers of energy. Conventional biochemical treatment having reached an impasse, the exploration of gene therapeutic approaches for patients with mtDNA defects is warranted. For now mitochondrial gene therapy appears to be only theoretical and speculative. Any possibility for gene replacement is dependent on the development of an efficient mitochondrial transfection vector. In this review we describe the current state of the development of mitochondria-specific DNA delivery systems. We summarize our own efforts in exploring the properties of dequalinium and other similar cationic bolaamphiphiles with delocalized charge centers, for the design of a vector suited for the transport of DNA to mitochondria in living cells. Further, we outline some unique hurdles that need to be overcome if the development of such delivery systems is to progress.

  3. Integrated Approach to Malaria Control

    PubMed Central

    Shiff, Clive

    2002-01-01

    Malaria draws global attention in a cyclic manner, with interest and associated financing waxing and waning according to political and humanitarian concerns. Currently we are on an upswing, which should be carefully developed. Malaria parasites have been eliminated from Europe and North America through the use of residual insecticides and manipulation of environmental and ecological characteristics; however, in many tropical and some temperate areas the incidence of disease is increasing dramatically. Much of this increase results from a breakdown of effective control methods developed and implemented in the 1960s, but it has also occurred because of a lack of trained scientists and control specialists who live and work in the areas of endemic infection. Add to this the widespread resistance to the most effective antimalarial drug, chloroquine, developing resistance to other first-line drugs such as sulfadoxine-pyrimethamine, and resistance of certain vector species of mosquito to some of the previously effective insecticides and we have a crisis situation. Vaccine research has proceeded for over 30 years, but as yet there is no effective product, although research continues in many promising areas. A global strategy for malaria control has been accepted, but there are critics who suggest that the single strategy cannot confront the wide range of conditions in which malaria exists and that reliance on chemotherapy without proper control of drug usage and diagnosis will select for drug resistant parasites, thus exacerbating the problem. An integrated approach to control using vector control strategies based on the biology of the mosquito, the epidemiology of the parasite, and human behavior patterns is needed to prevent continued upsurge in malaria in the endemic areas. PMID:11932233

  4. Schwinger's Approach to Einstein's Gravity

    NASA Astrophysics Data System (ADS)

    Milton, Kim

    2012-05-01

    Albert Einstein was one of Julian Schwinger's heroes, and Schwinger was greatly honored when he received the first Einstein Prize (together with Kurt Godel) for his work on quantum electrodynamics. Schwinger contributed greatly to the development of a quantum version of gravitational theory, and his work led directly to the important work of (his students) Arnowitt, Deser, and DeWitt on the subject. Later in the 1960's and 1970's Schwinger developed a new formulation of quantum field theory, which he dubbed Source Theory, in an attempt to get closer contact to phenomena. In this formulation, he revisited gravity, and in books and papers showed how Einstein's theory of General Relativity emerged naturally from one physical assumption: that the carrier of the gravitational force is a massless, helicity-2 particle, the graviton. (There has been a minor dispute whether gravitational theory can be considered as the massless limit of a massive spin-2 theory; Schwinger believed that was the case, while Van Dam and Veltman concluded the opposite.) In the process, he showed how all of the tests of General Relativity could be explained simply, without using the full machinery of the theory and without the extraneous concept of curved space, including such effects as geodetic precession and the Lense-Thirring effect. (These effects have now been verified by the Gravity Probe B experiment.) This did not mean that he did not accept Einstein's equations, and in his book and full article on the subject, he showed how those emerge essentially uniquely from the assumption of the graviton. So to speak of Schwinger versus Einstein is misleading, although it is true that Schwinger saw no necessity to talk of curved spacetime. In this talk I will lay out Schwinger's approach, and the connection to Einstein's theory.

  5. Overview of Approach to 'Victoria'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1

    This image from the Mars Orbiter Camera aboard NASA's Mars Global Surveyor spacecraft shows an overview of 'Victoria Crater' and a portion of the area NASA's Mars Exploration Rover Opportunity has covered to reach the enormous depression.

    Images such as this one from the Mars Orbiter Camera on NASA's Mars Global Surveyor are helping scientists and engineers decide the best path for NASA's Mars Exploration Rover Opportunity as it approaches 'Victoria Crater.'

    In figure 1, a blue dot indicates 'Cape Verde' and a red dot 'Cabo Frio.' These two points mark the extent of the crater visible from the rover's position on its 945th Martian day, or sol (Sept. 20, 2006), a location it had reached two sols earlier and from which much of this monster depression was still out of sight. The green annotations indicate 'Duck Bay,' a location expected to allow a view to the other side of the crater. A dune, or ripple, is to the left of the crater, right in front of the green dot location. This is where the team initially talked about sending Opportunity for the rover's first view down into the crater. After further consideration, the team opted for a drive to the right of that ripple (south of the green dot) near the rim.

    The yellow lines that surround and intersect Victoria Crater are used to measure the crater and the distance to the far 'bays.' North is up. Victoria Crater is about 800 meters (half a mile) in diameter.

  6. Approaches to adolescent pregnancy prevention.

    PubMed

    Haffner, D; Casey, S

    1986-09-01

    The US has one of the highest teenage pregnancy rates in the industrialized world, over 1,000,000 a year. This can add to social problems including poverty, unemployment, family breakup, juvenile crime, school dropouts, and child abuse. In several studies various approaches have been developed and it is concluded that teens must not only be given the knowledge to avoid teen pregnancies, but the motivation to do so. Sex education is an important part of pregnancy prevention, but few programs go beyond the facts of reproduction and less than 14% of them are 40 hours long. Studies have shown mixed results as to the effect of education on teen pregnancy. There are many programs that have been developed by different communities, including computer programs and youth service agencies. Religious groups also play an important part in sex education and they have some distinct advantages in affecting teens' sexual values and activities. Education programs for teen's parents appear to be very important since studies show when sexuality is discussed at home, the teens begin activity later and use birth control more. Clinics have had difficulty recruiting and retaining teen patients and devote special attention to establishing a rapport with them. The school-based clinic is becoming increasingly popular and can provide birth control counseling, contraceptives, family planning clinic referral, examinations, pregnancy testing, and prenatal care. There success is due to confidentiality, convenience, and comprehensive service. However, since nearly all efforts on teen pregnancy prevention are directed at girls, 1/2 of those involved in teen pregnancies--males--are not participating in programs. This must change for longterm success of these programs and also the involvement of the community and media.

  7. Transconjunctival dacryocystorhinostomy: An aesthetic approach

    PubMed Central

    Ganguly, Anasua; Ramarao, Kesarpu; Mohapatra, Samir; Rath, Suryasnata

    2016-01-01

    Purpose: To report the anatomical and cosmetic outcome of transconjunctival dacryocystorhinostomy (TDCR) in an Asian Indian population. Methods: TDCR was initially performed in cadaver eyes followed by patients with primary acquired nasolacrimal duct obstruction (NLDO). This was a prospective noncomparative case series of all consecutive TDCRs performed between April 2013 and June 2015. Outcome measures were anatomical patency, epiphora, presence of diplopia, aesthetic outcome, and health status. Results: A total of 17 (18 eyes) patients with a mean age 43.9 ± 11.8 years (range, 32–75) were included in the study. Eight were males, and one patient underwent TDCR in both eyes. TDCR was successfully performed in 15/18 (82%) eyes under local anesthesia. Procedure converted to transcutaneous external DCR in two and dacryocystectomy in one patient each. Mean duration of surgery was 52.6 (range, 29–110) min. Anatomical patency and relief from epiphora was achieved in all (15/15) eyes after TDCR at a median follow-up of 15.5 months. At final follow-up, objective assessment of the cosmetic outcome graded the surgical scar at the lateral canthus as invisible in all except one and conjunctival fornix as visible only after eyelid eversion in all patients. Disturbance of the medial fat pad was not seen in any patient. A questionnaire-based health status evaluation showed marked improvement in anxiety/depression before and after TDCR with an overall well-being score of 88 on a scale of 0–100 (worst–best) after TDCR. Conclusions: TDCR offers a promising aesthetic approach in patients with primary acquired NLDO and gives excellent functional and cosmetic outcome. PMID:28112129

  8. Hybrid biasing approaches for global variance reduction.

    PubMed

    Wu, Zeyun; Abdel-Khalik, Hany S

    2013-02-01

    A new variant of Monte Carlo-deterministic (DT) hybrid variance reduction approach based on Gaussian process theory is presented for accelerating convergence of Monte Carlo simulation and compared with Forward-Weighted Consistent Adjoint Driven Importance Sampling (FW-CADIS) approach implemented in the SCALE package from Oak Ridge National Laboratory. The new approach, denoted the Gaussian process approach, treats the responses of interest as normally distributed random processes. The Gaussian process approach improves the selection of the weight windows of simulated particles by identifying a subspace that captures the dominant sources of statistical response variations. Like the FW-CADIS approach, the Gaussian process approach utilizes particle importance maps obtained from deterministic adjoint models to derive weight window biasing. In contrast to the FW-CADIS approach, the Gaussian process approach identifies the response correlations (via a covariance matrix) and employs them to reduce the computational overhead required for global variance reduction (GVR) purpose. The effective rank of the covariance matrix identifies the minimum number of uncorrelated pseudo responses, which are employed to bias simulated particles. Numerical experiments, serving as a proof of principle, are presented to compare the Gaussian process and FW-CADIS approaches in terms of the global reduction in standard deviation of the estimated responses.

  9. An intelligent approach to nanotechnology

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2013-11-01

    Control counts for little without a guiding principle. Whether manipulating atoms with a scanning probe or controlling carrier concentration in thin film deposition, intelligent intervention is required to steer the process from aimless precision towards a finely optimized design. In this issue G M Sacha and P Varona describe how artificial intelligence approaches can help towards modelling and simulating nanosystems, increasing our grasp of the nuances of these systems and how to optimize them for specific applications [1]. More than a labour-saving technique their review also suggests how genetic algorithms and artificial neural networks can supersede existing capabilities to tackle some of the challenges in moving a range of nanotechnologies forward. Research has made giant strides in determining not just what system parameters enhance performance but how. Nanoparticle synthesis is a typical example, where the field has shifted from simple synthesis and observation to unearthing insights as to dominating factors that can be identified and enlisted to control the morphological and chemical properties of synthesized products. One example is the neat study on reaction media viscosity for silver nanocrystal synthesis, where Park, Im and Park in Korea demonstrated a level of size control that had previously proved hard to achieve [2]. Silver nanoparticles have many potential applications including catalysis [3], sensing [4] and surface enhanced Raman scattering [5]. In their study, Park and colleagues obtain size-controlled 30 nm silver nanocrystals in a viscosity controlled medium of 1,5-pentanediol and demonstrate their use as sacrificial cores for the fabrication of a low-refractive filler. Another nanomaterial that has barely seen an ebb in research activity over the past two decades is ZnO, with a legion of reports detailing how to produce ZnO in different nanoscale forms from rods [6], belts [7] and flowers [8] to highly ordered arrays of vertically aligned

  10. Biotechnology Approaches to Life Detection

    NASA Technical Reports Server (NTRS)

    Steele, Andrew; McKay, David; Schweitzer, Mary

    2001-01-01

    The direct detection of organic biomarkers for living or fossil microbes on Mars by an in situ instrument is a worthy goal for future lander missions. Several new and innovative biotechnology approaches are being explored. Firstly we have proposed an instrument based on immunological reactions to specific antibodies to cause activation of fluorescent stains. Antibodies are raised or acquired to a variety of general and specific substances that might be in Mars soil. These antibodies are then combined with various fluorescent stains and applied to micron sized numbered spots on a small (2-3 cm) test plate where they become firmly attached after freeze drying. Using technology that has been developed for gene mining in DNA technology up to 10,000 tests per square inch can now be applied to a test plate. On Mars or the planet/moon of interest, a sample of soil from a trench or drill core is extracted with water and/or an organic solvent and ultrasonication and then applied to the test plate. Any substance, which has an antibody on the test plate, will react with its antibody and activate its fluorescent stain. At the moment a small UV light source will illuminate the test plate, which is observed with a small CCD camera, although other detection systems will be applied. The numbered spots that fluoresce indicate the presence of the tested-for substance, and the intensity indicates relative amounts. Furthermore with up to a thousand test plates available false positives and several variations of antibody can also be screened for. The entire instrument can be quite small and light, on the order of 10 cm in each dimension. A possible choice for light source may be small UV lasers at several wavelengths. Some of the wells or spots can contain simply standard fluorescent stains used to detect live cells, dead cells, DNA, etc. The stains in these spots may be directly activated, with no antibodies being necessary. The proposed system will look for three classes of

  11. Physical approach to complex systems

    NASA Astrophysics Data System (ADS)

    Kwapień, Jarosław; Drożdż, Stanisław

    2012-06-01

    Typically, complex systems are natural or social systems which consist of a large number of nonlinearly interacting elements. These systems are open, they interchange information or mass with environment and constantly modify their internal structure and patterns of activity in the process of self-organization. As a result, they are flexible and easily adapt to variable external conditions. However, the most striking property of such systems is the existence of emergent phenomena which cannot be simply derived or predicted solely from the knowledge of the systems’ structure and the interactions among their individual elements. This property points to the holistic approaches which require giving parallel descriptions of the same system on different levels of its organization. There is strong evidence-consolidated also in the present review-that different, even apparently disparate complex systems can have astonishingly similar characteristics both in their structure and in their behaviour. One can thus expect the existence of some common, universal laws that govern their properties. Physics methodology proves helpful in addressing many of the related issues. In this review, we advocate some of the computational methods which in our opinion are especially fruitful in extracting information on selected-but at the same time most representative-complex systems like human brain, financial markets and natural language, from the time series representing the observables associated with these systems. The properties we focus on comprise the collective effects and their coexistence with noise, long-range interactions, the interplay between determinism and flexibility in evolution, scale invariance, criticality, multifractality and hierarchical structure. The methods described either originate from “hard” physics-like the random matrix theory-and then were transmitted to other fields of science via the field of complex systems research, or they originated elsewhere but

  12. Electronic structure of alkali-metal/alkaline-earth-metal fluorine beryllium borate NaSr3Be3B3O9F4 single crystal: DFT approach

    NASA Astrophysics Data System (ADS)

    Reshak, A. H.; Kamarudin, H.; Auluck, S.

    2015-10-01

    The electronic band structure, total and angular momentum resolved projected density of states for NaSr3Be3B3O9F4 are calculated using the all-electron full potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) method. The calculations are performed within four exchange correlations namely; local density approximation (LDA), general gradient approximation (PBE-GGA), Engel-Vosko generalized gradient approximation (EVGGA) and the recently modified Becke-Johnson potential (mBJ). Calculations suggest that NaSr3Be3B3O9F4 is a direct wide band gap semiconductor. The exchange correlations potentials exhibit significant influence on the value of the energy gap being about 4.82 eV (LDA), 5.16 eV (GGA), 6.20 (EVGGA) and 7.20 eV (mBJ). The mBJ approach succeed by large amount in bringing the calculated energy gap closer to the experimental one (7.28 eV). The angular momentum resolved projected density of states shows the existence of a strong hybridization between the various orbitals. In additional we have calculated the electronic charge density distribution in two crystallographic planes namely (1 0 1) and (0 0 -1) to visualized the chemical bonding characters.

  13. Numerical Simulation of Heliospheric Transients Approaching Geospace

    DTIC Science & Technology

    2009-12-01

    12/15/08 – 12/14/09 Numerical Simulation of Heliospheric Transients Approaching Geospace Report by Dusan Odstrcil, University of Colorado...simulations of heliospheric transients approaching geospace . The project was supervised by Dr. Dusan Odstrcil at the University of Colorado (CU...plays a key role in the prediction accuracy of heliospheric transients approaching geospace . This report presents main results achieved within the

  14. Patient Privacy: A Consumer Protection Approach

    PubMed Central

    Brannigan, Vincent M.

    1983-01-01

    In the United States, a “Constitutional Analysis” of medical data privacy has been so far unsuccessful in obtaining significant protection. Statutory protection has evolved primarily to protect the citizen against the state, not to vindicate the privacy interest of the individual. A “Consumer Protection” approach rather than a right to privacy approach can be used to develop a coherent, practical approach to the needs of various parties in the health care system in the U.S.

  15. A regularization approach to hydrofacies delineation

    SciTech Connect

    Wohlberg, Brendt; Tartakovsky, Daniel

    2009-01-01

    We consider an inverse problem of identifying complex internal structures of composite (geological) materials from sparse measurements of system parameters and system states. Two conceptual frameworks for identifying internal boundaries between constitutive materials in a composite are considered. A sequential approach relies on support vector machines, nearest neighbor classifiers, or geostatistics to reconstruct boundaries from measurements of system parameters and then uses system states data to refine the reconstruction. A joint approach inverts the two data sets simultaneously by employing a regularization approach.

  16. A Hybrid Approach to Clinical Question Answering

    DTIC Science & Technology

    2014-11-01

    participation in TREC, we submitted a single run using a hybrid Natural Language Processing ( NLP )-driven approach to accomplish the given task. Evaluation re...for the CDS track uses a variety of NLP - based techniques to address the clinical questions provided. We present a description of our approach, and...discuss our experimental setup, results and eval- uation in the subsequent sections. 2 Description of Our Approach Our hybrid NLP -driven method presents a

  17. Two Approaches to Calibration in Metrology

    SciTech Connect

    Campanelli, Mark

    2014-04-01

    Inferring mathematical relationships with quantified uncertainty from measurement data is common to computational science and metrology. Sufficient knowledge of measurement process noise enables Bayesian inference. Otherwise, an alternative approach is required, here termed compartmentalized inference, because collection of uncertain data and model inference occur independently. Bayesian parameterized model inference is compared to a Bayesian-compatible compartmentalized approach for ISO-GUM compliant calibration problems in renewable energy metrology. In either approach, model evidence can help reduce model discrepancy.

  18. Optimal online learning: a Bayesian approach

    NASA Astrophysics Data System (ADS)

    Solla, Sara A.; Winther, Ole

    1999-09-01

    A recently proposed Bayesian approach to online learning is applied to learning a rule defined as a noisy single layer perceptron. In the Bayesian online approach, the exact posterior distribution is approximated by a simple parametric posterior that is updated online as new examples are incorporated to the dataset. In the case of binary weights, the approximate posterior is chosen to be a biased binary distribution. The resulting online algorithm is shown to outperform several other online approaches to this problem.

  19. Constrained neural approaches to quadratic assignment problems.

    PubMed

    Ishii, S; Sato, M

    1998-08-01

    In this paper, we discuss analog neural approaches to the quadratic assignment problem (QAP). These approaches employ a hard constraints scheme to restrict the domain space, and are able to obtain much improved solutions over conventional neural approaches. Since only a few strong heuristics for QAP have been known to date, our approaches are good alternatives, capable of obtaining fairly good solutions in a short period of time. Some of them can also be applied to large-scale problems, say of size N>/=300.

  20. Concurrency-based approaches to parallel programming

    NASA Technical Reports Server (NTRS)

    Kale, L.V.; Chrisochoides, N.; Kohl, J.; Yelick, K.

    1995-01-01

    The inevitable transition to parallel programming can be facilitated by appropriate tools, including languages and libraries. After describing the needs of applications developers, this paper presents three specific approaches aimed at development of efficient and reusable parallel software for irregular and dynamic-structured problems. A salient feature of all three approaches in their exploitation of concurrency within a processor. Benefits of individual approaches such as these can be leveraged by an interoperability environment which permits modules written using different approaches to co-exist in single applications.

  1. Translabyrinthine approach for acoustic tumor removal. 1992.

    PubMed

    Brackmann, Derald E; Green, J Douglas

    2008-04-01

    The translabyrinthine approach is the most direct route to the cerebellopontine angle. It is the preferred approach for removal of all tumors in patients with poor hearing and for large tumors when the likelihood of hearing preservation is slight. This approach offers the advantages of minimum cerebellar retraction, identification of the facial nerve proximally and medially, and the ability to repair immediately the facial nerve if it is severed during acoustic tumor removal. This approach has the lowest morbidity with regard to spinal fluid leaks and also postoperative headaches.

  2. Remediation Optimization: Definition, Scope and Approach

    EPA Pesticide Factsheets

    This document provides a general definition, scope and approach for conducting optimization reviews within the Superfund Program and includes the fundamental principles and themes common to optimization.

  3. A Mixed Approach Of Automated ECG Analysis

    NASA Astrophysics Data System (ADS)

    De, A. K.; Das, J.; Majumder, D. Dutta

    1982-11-01

    ECG is one of the non-invasive and risk-free technique for collecting data about the functional state of the heart. However, all these data-processing techniques can be classified into two basically different approaches -- the first and second generation ECG computer program. Not the opposition, but simbiosis of these two approaches will lead to systems with the highest accuracy. In our paper we are going to describe a mixed approach which will show higher accuracy with lesser amount of computational work. Key Words : Primary features, Patients' parameter matrix, Screening, Logical comparison technique, Multivariate statistical analysis, Mixed approach.

  4. Concurrency-based approaches to parallel programming

    SciTech Connect

    Kale, L.V.; Chrisochoides, N.; Kohl, J.

    1995-07-17

    The inevitable transition to parallel programming can be facilitated by appropriate tools, including languages and libraries. After describing the needs of applications developers, this paper presents three specific approaches aimed at development of efficient and reusable parallel software for irregular and dynamic-structured problems. A salient feature of all three approaches in their exploitation of concurrency within a processor. Benefits of individual approaches such as these can be leveraged by an interoperability environment which permits modules written using different approaches to co-exist in single applications.

  5. A Probabilistic Approach to Aeropropulsion System Assessment

    NASA Technical Reports Server (NTRS)

    Tong, Michael T.

    2000-01-01

    A probabilistic approach is described for aeropropulsion system assessment. To demonstrate this approach, the technical performance of a wave rotor-enhanced gas turbine engine (i.e. engine net thrust, specific fuel consumption, and engine weight) is assessed. The assessment accounts for the uncertainties in component efficiencies/flows and mechanical design variables, using probability distributions. The results are presented in the form of cumulative distribution functions (CDFs) and sensitivity analyses, and are compared with those from the traditional deterministic approach. The comparison shows that the probabilistic approach provides a more realistic and systematic way to assess an aeropropulsion system.

  6. The probabilistic approach to human reasoning.

    PubMed

    Oaksford, M; Chater, N

    2001-08-01

    A recent development in the cognitive science of reasoning has been the emergence of a probabilistic approach to the behaviour observed on ostensibly logical tasks. According to this approach the errors and biases documented on these tasks occur because people import their everyday uncertain reasoning strategies into the laboratory. Consequently participants' apparently irrational behaviour is the result of comparing it with an inappropriate logical standard. In this article, we contrast the probabilistic approach with other approaches to explaining rationality, and then show how it has been applied to three main areas of logical reasoning: conditional inference, Wason's selection task and syllogistic reasoning.

  7. Multidomain approach for calculating compressible flows

    NASA Technical Reports Server (NTRS)

    Cambier, L.; Chazzi, W.; Veuillot, J. P.; Viviand, H.

    1982-01-01

    A multidomain approach for calculating compressible flows by using unsteady or pseudo-unsteady methods is presented. This approach is based on a general technique of connecting together two domains in which hyperbolic systems (that may differ) are solved with the aid of compatibility relations associated with these systems. Some examples of this approach's application to calculating transonic flows in ideal fluids are shown, particularly the adjustment of shock waves. The approach is then applied to treating a shock/boundary layer interaction problem in a transonic channel.

  8. Teaching Programming to Novices: A Review of Approaches and Tools.

    ERIC Educational Resources Information Center

    Brusilovsky, P.; And Others

    Three different approaches to teaching introductory programming are reviewed: the incremental approach, the sub-language approach, and the mini-language approach. The paper analyzes all three approaches, providing a brief history of each and describing an example of a programming environment supporting this approach. In the incremental approach,…

  9. Neuroevolutional Approach to Cerebral Palsy and Speech.

    ERIC Educational Resources Information Center

    Mysak, Edward D.

    Intended for cerebral palsy specialists, the book emphasizes the contribution that a neuroevolutional approach to therapy can make to habilitation goals of the child with cerebral palsy and applies the basic principles of the Bobath approach to therapy. The first section discusses cerebral palsy as a reflection of disturbed neuro-ontogenisis and…

  10. Teaching Science through a Systems Approach

    ERIC Educational Resources Information Center

    Llewellyn, Douglas; Johnson, Scott

    2008-01-01

    Based on the recommendation of the AAAS and the NRC, middle level science is the rightful introduction for a systems approach, including the study of its parts, subsystems, interconnections, and interrelationships. Dr. Seuss's "The Lorax" provides an excellent opportunity to combine ecological consequences within a systems approach (Sweeney 2001).…

  11. The Cognitive Behavioral Approach to Weight Maintenance.

    ERIC Educational Resources Information Center

    Girdano, Dorothy Dusek

    The cognitive behavioral approach to weight maintenance assumes that obese people should be concerned with weight control rather than weight loss, and it embraces both the behavioral approach and a maintenance program which examines risks, value priorities, and the basic principles of weight loss/weight gain. The University of Maryland offers a…

  12. The Tutor's Approach in Base Groups (PBL)

    ERIC Educational Resources Information Center

    Silen, Charlotte

    2006-01-01

    In this article, the concept of approach related to tutor functioning in problem-based learning (PBL) is explored and the significance of a phenomenological perspective of the body in relation to learning and tutoring is investigated. The aim has been to understand the concept of approach in a context where the individual, thoughts, emotions and…

  13. An Experiential Approach to Cultural Intelligence Education

    ERIC Educational Resources Information Center

    MacNab, Brent R.

    2012-01-01

    Cultural intelligence (CQ) represents a promising advancement in the area of cross-cultural training and management. Experiential approaches for CQ development have been proposed as highly effective; however, there is a lack of CQ-specific approaches in the management literature. This work overviews the concept of cultural intelligence and its…

  14. Graduate Cohort Approach in Teacher Education

    ERIC Educational Resources Information Center

    Mattson-Gearhart, Jeanine

    2012-01-01

    The use of the cohorts in teacher education has steadily increased over the last decade. Research indicates both beneficial and negative aspects to this approach, with the field undecided. This study focuses on a Midwestern university's accelerated graduate program for special educators. The program uses a mixed cohort approach to model…

  15. SPATIAL APPROACH TO PLANNING THE PHYSICAL ENVIRONMENT.

    ERIC Educational Resources Information Center

    BELLOMY, CLEON C.; CAUDILL, WILLIAM W.

    THE PURPOSE OF THIS REPORT DEFINES THE SPATIAL APPROACH TO PLANNING THE PHYSICAL ENVIRONMENT AND SUGGESTS A MORE NATURAL APPROACH TO A LESS RESTRICTED ARCHITECTURE. ONE OF THE TWO BASIC ARCHITECTURAL ELEMENTS IN THE SPATIAL CONCEPT IS THE HORIZONTAL SCREEN WHICH KEEPS THE SUN AND RAIN OFF, LETS IN LIGHT, KEEPS OUT SUN HEAT, RETAINS ROOM HEAT, AND…

  16. Interpreting Native American Literature: An Archetypal Approach.

    ERIC Educational Resources Information Center

    Sevillano, Mando

    1986-01-01

    Compares two approaches to discussing Indian literature and religion. Demonstrates Jungian archetypal approach as transcultural method of analyzing Indian literature. Relates and analyzes Hopi traditional story. Emphasizes accessibility of Native American literature to the non-Indian while supporting multicultural plurality of interpretations.…

  17. The Wedding Project: Introducing the Project Approach

    ERIC Educational Resources Information Center

    Sorrels, Barbara; Norris, Deborah; Sheeran, Linda

    2004-01-01

    Constructivist education, based on the theories of Piaget and Vygotsky, advocates an approach to curriculum and teaching that is student centered, inquiry based, integrated and intellectually engaging. One teaching strategy that provides such an experience is the Project Approach, reflective of the pedagogy of John Dewey and introduced as a model…

  18. Basic Employability Skills: A Triangular Design Approach

    ERIC Educational Resources Information Center

    Rosenberg, Stuart; Heimler, Ronald; Morote, Elsa-Sofia

    2012-01-01

    Purpose: This paper seeks to examine the basic employability skills needed for job performance, the reception of these skills in college, and the need for additional training in these skills after graduation. Design/methodology/approach: The research was based on a triangular design approach, in which the attitudes of three distinct groups--recent…

  19. A Novel Approach to Teaching Teamwork

    ERIC Educational Resources Information Center

    Drake, Robert; Goldsmith, Geraldine; Strachan, Rebecca

    2006-01-01

    Teamwork is widely recognised as an important skill both generally and in the context of the computing industry. The majority of approaches to teaching teamwork are "practically" based and in higher education are often designed to run over a number of weeks. We required an approach that would work over a concentrated period of five days…

  20. Evaluation and Opportunities in Overtraining Approaches

    ERIC Educational Resources Information Center

    Roose, Jolanda; de Vries, Wouter R.; Schmikli, Sandor L.; Backx, Frank J. G.; van Doornen, Lorenz J. P.

    2009-01-01

    Overtraining (OT) as a sports phenomenon can be caused by stressors on various levels (physical, emotional, psychological, and social) and evokes responses on these levels. This study evaluated research and new opportunities in the field of OT by introducing an integrated multidisciplinary approach, based on the single and multistressors approach.…

  1. Natural Approaches to Reading and Writing.

    ERIC Educational Resources Information Center

    Antonacci, Patricia; Hedley, Carolyn

    Based on a two-day presentation workshop on early reading and writing approaches, the 12 essays in this book discuss the development of literacy, natural approaches in developing literacy, and supporting literacy development. Essays in the book are: (1) "Theories of Natural Language" (Carolyn N. Hedley); (2) "Oral Language…

  2. A Systems Approach to School Construction.

    ERIC Educational Resources Information Center

    Boice, John

    Systems approach as used in this paper refers to the process of a building coming into being. The systems approach attempts to relate the processes of factory production and school construction in that the problems of the spacing and fitting of construction components are considered at the beginning of the design stage of construction. For the…

  3. The "White Canvas" Approach to Beginning Conducting.

    ERIC Educational Resources Information Center

    Mailman, Matthew

    2000-01-01

    Discusses the white canvas approach to beginning conducting, a basic mirror conducting of both hands generating the symmetrical takt, or beat, that represents the basic foundation of conducting. Focuses on such issues as conducting as communication, conducting at the tip of the baton, and extension beyond the white canvas approach. (CMK)

  4. The RESPECT Approach to Tailored Telephone Education

    ERIC Educational Resources Information Center

    Brouse, Corey H.; Basch, Charles E.; Wolf, Randi L.

    2008-01-01

    Objective: The objective of the RESPECT approach to tailored telephone education (TTE) is described. This approach was shown to be highly effective through a randomized intervention trial for increasing the rate of colorectal cancer (CRC) screening. Methods: At the conclusion of the trial, the investigators identified the main principles that…

  5. A Professional Approach to PR Writing.

    ERIC Educational Resources Information Center

    Nager, Norman R.

    After reviewing some of the problems involved in a traditional approach to teaching, this paper introduces a teaching system based on a patterned approach to the public relations writing process. The system format which is presented involves an analysis of persuasive communication components, programmed questioning of traditional premises, and…

  6. Computer-Based Training: An Institutional Approach.

    ERIC Educational Resources Information Center

    Barker, Philip; Manji, Karim

    1992-01-01

    Discussion of issues related to computer-assisted learning (CAL) and computer-based training (CBT) describes approaches to electronic learning; principles underlying courseware development to support these approaches; and a plan for creation of a CAL/CBT development center, including its functional role, campus services, staffing, and equipment…

  7. Four Values Education Approaches for Science Teaching.

    ERIC Educational Resources Information Center

    Barman, Charles R.

    1980-01-01

    Four types of values education approaches for use in teaching in high school biology classes are described. The approaches include moral development, values clarification, action learning, and analysis. Inculcation is mentioned but not discussed because the author feels that it does little to help develop values. (SA)

  8. The Potential of the Portfolio Approach

    ERIC Educational Resources Information Center

    Cavanna, Anthony; Olchefske, Joseph; Fleischman, Steve

    2006-01-01

    Despite some encouraging signs that education reform efforts are raising achievement in one school here and another there, such piecemeal approaches have not yet yielded positive systemic results. To achieve districtwide improvement, a growing number of school systems are adopting a "portfolio approach" to district governance by replacing the…

  9. Empirical Approaches to the Birthday Problem

    ERIC Educational Resources Information Center

    Flores, Alfinio; Cauto, Kevin M.

    2012-01-01

    This article will describe two activities in which students conduct experiments with random numbers so they can see that having at least one repeated birthday in a group of 40 is not unusual. The first empirical approach was conducted by author Cauto in a secondary school methods course. The second empirical approach was used by author Flores with…

  10. A Gentle Approach for Young Infants.

    ERIC Educational Resources Information Center

    Suskind, Diana; Kozma, Marta

    The Gentle Approach is a method for lifting infants younger than 6 months that promotes security and reassurance during adult-imposed changes in position. Developed at the Emmi Pilker National Methodological Institute for Residential Nurseries in Budapest, Hungary, the approach provides continual support and less opportunity for unprotected…

  11. Analysis of radial basis function interpolation approach

    NASA Astrophysics Data System (ADS)

    Zou, You-Long; Hu, Fa-Long; Zhou, Can-Can; Li, Chao-Liu; Dunn, Keh-Jim

    2013-12-01

    The radial basis function (RBF) interpolation approach proposed by Freedman is used to solve inverse problems encountered in well-logging and other petrophysical issues. The approach is to predict petrophysical properties in the laboratory on the basis of physical rock datasets, which include the formation factor, viscosity, permeability, and molecular composition. However, this approach does not consider the effect of spatial distribution of the calibration data on the interpolation result. This study proposes a new RBF interpolation approach based on the Freedman's RBF interpolation approach, by which the unit basis functions are uniformly populated in the space domain. The inverse results of the two approaches are comparatively analyzed by using our datasets. We determine that although the interpolation effects of the two approaches are equivalent, the new approach is more flexible and beneficial for reducing the number of basis functions when the database is large, resulting in simplification of the interpolation function expression. However, the predicted results of the central data are not sufficiently satisfied when the data clusters are far apart.

  12. A Network Approach to Curriculum Quality Assessment

    ERIC Educational Resources Information Center

    Jordens, J. Zoe; Zepke, Nick

    2009-01-01

    This paper argues for an alternative approach to quality assurance in New Zealand universities that locates evaluation not with external auditors but with members of the teaching team. In the process, aspects of network theories are introduced as the basis for an approach to quality assurance. From this, the concept of networks is extended to…

  13. Instructional Approaches in Teaching the Holocaust

    ERIC Educational Resources Information Center

    Lindquist, David H.

    2011-01-01

    Holocaust education requires teachers to carefully determine which instructional approaches ensure effective teaching of the subject while avoiding potential difficulties. The article identifies several complicating factors that must be considered when making pedagogical decisions. It then examines five methodological approaches that can be used…

  14. Methodological Approaches to Online Scoring of Essays.

    ERIC Educational Resources Information Center

    Chung, Gregory K. W. K.; O'Neil, Harold F., Jr.

    This report examines the feasibility of scoring essays using computer-based techniques. Essays have been incorporated into many of the standardized testing programs. Issues of validity and reliability must be addressed to deploy automated approaches to scoring fully. Two approaches that have been used to classify documents, surface- and word-based…

  15. Mixed Methods Approaches in Family Science Research

    ERIC Educational Resources Information Center

    Plano Clark, Vicki L.; Huddleston-Casas, Catherine A.; Churchill, Susan L.; Green, Denise O'Neil; Garrett, Amanda L.

    2008-01-01

    The complex phenomena of interest to family scientists require the use of quantitative and qualitative approaches. Researchers across the social sciences are now turning to mixed methods designs that combine these two approaches. Mixed methods research has great promise for addressing family science topics, but only if researchers understand the…

  16. Approaches to Research in HRD. Symposium.

    ERIC Educational Resources Information Center

    2002

    This document contains three papers from a symposium on approaches to research in human resource development (HRD). "HRD, Feminism, and Adult Education: A Foundation for Collaborative Approaches to Research and Practice" (Yvonne M. Johnson) identifies common interests among HRD professionals, feminists, and practitioners in the field of…

  17. Florida Residents' Preferred Approach to Sexuality Education

    ERIC Educational Resources Information Center

    Howard-Barr, Elissa M.; Moore, Michele Johnson

    2007-01-01

    Although there is widespread support for sexuality education, whether to use an abstinence-only or comprehensive approach is hotly debated. This study assessed Florida residents preferred approach to school-based sexuality education. The 641 respondents were selected by random digit dialing, using methods to ensure ethnic and geographic…

  18. The Continued Development of the Structural Approach.

    ERIC Educational Resources Information Center

    Sweet, Waldo E.

    1967-01-01

    A brief discussion of traditional Latin textbooks is followed by a survey of the first attempts at new materials (emphasizing integration of audiovisual aids and texts) at the William Penn Charter School and at the University of Michigan. The body of the article considers the structural approach, using "Latin: A Structural Approach"…

  19. "1984": A Confessional Reading and Teaching Approach.

    ERIC Educational Resources Information Center

    Tanenbaum, Miles

    1989-01-01

    Describes an approach to teaching George Orwell's "1984," emphasizing the main characters' struggles through the themes of innocence and experience, conformity and rebellion, love and hate, discovery and creation, and death. Notes that this reader-response approach forces students into the process of self-examination. (MM)

  20. 49 CFR 236.760 - Locking, approach.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.760 Locking, approach. Electric locking effective while a train is approaching, within a specified distance, a signal displaying an aspect to proceed, and which prevents, until after the expiration of a...

  1. Learning Centers: A Personalized Approach to Mainstreaming.

    ERIC Educational Resources Information Center

    Babich, Betsy; Thompson, Cecelia

    The manual provides information about using learning centers in mainstreamed home economics classrooms. The initial chapter introduces the rationale for the approach and presents a three-stage model depicting an integrational approach to mainstreaming. Chapter 2 outlines typical characteristics and recommendations for accommodating students with…

  2. The "Rear-View Mirror" Approach.

    ERIC Educational Resources Information Center

    Nord, James

    1987-01-01

    The "rear-view mirror" approach referred to by McLuhan refers to new media being used with the methods of older, different media. A Sens-it (SENtence- SENtence- SITuation) cell model is suggested as an effective use of interactive videodisk systems in contrast to the communicative competence approach. (Author/LMO)

  3. An Agile Course-Delivery Approach

    ERIC Educational Resources Information Center

    Capellan, Mirkeya

    2009-01-01

    In the world of software development, agile methodologies have gained popularity thanks to their lightweight methodologies and flexible approach. Many advocates believe that agile methodologies can provide significant benefits if applied in the educational environment as a teaching method. The need for an approach that engages and motivates…

  4. Making Sense of Approaches to Moral Education

    ERIC Educational Resources Information Center

    Sanger, Matthew; Osguthorpe, Richard

    2005-01-01

    This paper presents a metatheoretical analysis of "approaches" to moral education and how we make sense of them. Such approaches are commonly analyzed with simple, binary category schemes, for example, being categorized as either 'indirect' or 'direct' in nature. This kind of minimal framework clearly oversimplifies the complex nature of any…

  5. Promoting School Connectedness through Whole School Approaches

    ERIC Educational Resources Information Center

    Rowe, Fiona; Stewart, Donald; Patterson, Carla

    2007-01-01

    Purpose: The purpose of this paper is to develop a framework to demonstrate the contribution of whole school approaches embodied by the health-promoting school approach, to the promotion of school connectedness, defined as the cohesiveness between diverse groups in the school community, including students, families, school staff and the wider…

  6. A Balanced Approach to Early Childhood Education.

    ERIC Educational Resources Information Center

    Lodish, Richard

    1996-01-01

    Based on 30 years' experience, the author advocates a balanced approach that accommodates extremes in four important areas: curriculum, teaching, structure, and classroom management. Using a whole-language approach to reading should not mean that phonics, spelling, or punctuation skills can't be taught. Authoritarian and open classroom structures…

  7. Competence: Conceptual Approach and Practice in France

    ERIC Educational Resources Information Center

    Le Deist, Francoise

    2009-01-01

    Purpose: The purpose of this article is to analyse the conceptual approaches to competence and practice in competence management in France. Design/methodology/approach: Extensive literature review, discussion with academic experts in the French competence network of AGRH and interviews concerning developments following the 2003 national agreement…

  8. The Lone Wolf Threat: A Different Approach

    DTIC Science & Technology

    2016-03-24

    intelligence communities and law enforcement agencies can employ asymmetric strategic approaches to aid in interdicting the lone wolf terrorist. 15...and a Golden Moment is identified in which intelligence communities and law enforcement agencies can employ asymmetric strategic approaches to aid ...and model presented in the thesis will further aid homeland security entities in combating this asymmetric threat. 40    CHAPTER 7: CONCLUSION

  9. Hierarchical approaches to VLSI circuit layout

    SciTech Connect

    Sarrafzadeh, M.

    1987-01-01

    This thesis studies two hierarchical approaches to the circuit-layout problem: the top-down approach and the bottom-up approach. The first part is devoted to the traditional top-down approach, and particularly, to an important subproblem thereof called the Channel Routing Problem (CRP). The complexity of CRP in three different layout modes - the reserved mode, the knock-knee mode, and the restricted-overlap mode - is studied. Besides the conventional square grid, two new grids - the alternate grid and the 45/sup 0/ grid - are considered, and their respective versatility is assessed. In the second part, a novel bottom-up technique for solving the layout problem is proposed. The strategy is to recursively interconnect a set of modules, in conformity with the design rules. The basic step consists of merging a pair of strongly-connected modules. This technique is elaborated on and the fundamental problems of this approach are discussed.

  10. Candidate Gene Identification Approach: Progress and Challenges

    PubMed Central

    Zhu, Mengjin; Zhao, Shuhong

    2007-01-01

    Although it has been widely applied in identification of genes responsible for biomedically, economically, or even evolutionarily important complex and quantitative traits, traditional candidate gene approach is largely limited by its reliance on the priori knowledge about the physiological, biochemical or functional aspects of possible candidates. Such limitation results in a fatal information bottleneck, which has apparently become an obstacle for further applications of traditional candidate gene approach on many occasions. While the identification of candidate genes involved in genetic traits of specific interest remains a challenge, significant progress in this subject has been achieved in the last few years. Several strategies have been developed, or being developed, to break the barrier of information bottleneck. Recently, being a new developing method of candidate gene approach, digital candidate gene approach (DigiCGA) has emerged and been primarily applied to identify potential candidate genes in some studies. This review summarizes the progress, application software, online tools, and challenges related to this approach. PMID:17998950

  11. Exercising self-control increases approach motivation.

    PubMed

    Schmeichel, Brandon J; Harmon-Jones, Cindy; Harmon-Jones, Eddie

    2010-07-01

    The present research tested the hypothesis that exercising self-control causes an increase in approach motivation. Study 1 found that exercising (vs. not exercising) self-control increases self-reported approach motivation. Study 2a identified a behavior--betting on low-stakes gambles--that is correlated with approach motivation but is relatively uncorrelated with self-control, and Study 2b observed that exercising self-control temporarily increases this behavior. Last, Study 3 found that exercising self-control facilitates the perception of a reward-relevant symbol (i.e., a dollar sign) but not a reward-irrelevant symbol (i.e., a percent sign). Altogether, these results support the hypothesis that exercising self-control temporarily increases approach motivation. Failures of self-control that follow from prior efforts at self-control (i.e., ego depletion) may be explained in part by increased approach motivation.

  12. Energy management - The delayed flap approach

    NASA Technical Reports Server (NTRS)

    Bull, J. S.

    1976-01-01

    Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

  13. Faces from sketches: a subspace synthesis approach

    NASA Astrophysics Data System (ADS)

    Li, Yung-hui; Savvides, Marios

    2006-04-01

    In real life scenario, we may be interested in face recognition for identification purpose when we only got sketch of the face images, for example, when police tries to identify criminals based on sketches of suspect, which is drawn by artists according to description of witnesses, what they have in hand is a sketch of suspects, and many real face image acquired from video surveillance. So far the state-of-the-art approach toward this problem tries to transform all real face images into sketches and perform recognition on sketch domain. In our approach we propose the opposite which is a better approach; we propose to generate a realistic face image from the composite sketch using a Hybrid subspace method and then build an illumination tolerant correlation filter which can recognize the person under different illumination variations. We show experimental results on our approach on the CMU PIE (Pose Illumination and Expression) database on the effectiveness of our novel approach.

  14. Path Integral Approach to Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Harris, Allison

    2016-09-01

    The Path Integral technique is an alternative formulation of quantum mechanics that is based on a Lagrangian approach. In its exact form, it is completely equivalent to the Hamiltonian-based Schrödinger equation approach. Developed by Feynman in the 1940's, following inspiration from Dirac, the path integral approach has been widely used in high energy physics, quantum field theory, and statistical mechanics. However, only in limited cases has the path integral approach been applied to quantum mechanical few-body scattering. We present a theoretical and computational development of the path integral method for use in the study of atomic collisions. Preliminary results are presented for some simple systems. Ultimately, this approach will be applied to few-body ion-atom collisions. Work supported by NSF grant PHY-1505217.

  15. Approach guidance for outer planet pioneer missions

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1975-01-01

    Onboard optical approach guidance measurements for spin-stabilized Pioneer-type spacecraft are discussed. Approach guidance measurement accuracy requirements are outlined. The application concept and operation principle of the V-slit star tracker are discussed within the context of approach guidance measurements and measurables. It is shown that the accuracy of onboard optical approach guidance measurements is inherently coupled to the stability characteristics of the spacecraft spin axis. Geometrical and physical measurement parameters are presented for Pioneer entry probe missions to Uranus via Jupiter or Saturn flyby. The impact of these parameters on both sensor instrumentation and measurement system design is discussed. The need for sensing extended objects is shown. The feasibility of implementing an onboard approach guidance measurement system for Pioneer-type spacecraft is indicated. Two Pioneer 10 onboard measurement experiments performed in May-June 1974 are described.

  16. STS-66 Edwards Landing Approach

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Atlantis approaches runway 22 at Edwards, California, to complete the STS-66 mission dedicated to the third flight of the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3), part of NASA's Mission to Planet Earth program. The astronauts also deployed and retrieved a free-flying satellite designed to study the middle and lower thermospheres and perform a series of experiments covering life sciences research and microgravity processing. The landing was at 7:34 a.m. (PST) 14 November 1994, after being waved off from the Kennedy Space Center, Florida, due to adverse weather. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to Earth and can be reused on

  17. XV-15 Tiltrotor Low Noise Approach Operations

    NASA Technical Reports Server (NTRS)

    Conner, David A.; Marcolini, Michael A.; Decker, William A.; Cline, John H.; Edwards, Bryan D.; Nicks, Colby O.; Klein, Peter D.

    1999-01-01

    Acoustic data have been acquired for the XV-15 tiltrotor aircraft performing approach operations for a variety of different approach profile configurations. This flight test program was conducted jointly by NASA, the U.S. Army, and Bell Helicopter Textron, Inc. (BHTI) in June 1997. The XV-15 was flown over a large area microphone array, which was deployed to directly measure the noise footprint produced during actual approach operations. The XV-15 flew realistic approach profiles that culminated in IGE hover over a landing pad. Aircraft tracking and pilot guidance was provided by a Differential Global Positioning System (DGPS) and a flight director system developed at BHTI. Approach profile designs emphasized noise reduction while maintaining handling qualities sufficient for tiltrotor commercial passenger ride comfort and flight safety under Instrument Flight Rules (IFR) conditions. A discussion of the approach profile design philosophy is provided. Five different approach profiles are discussed in detail -- 3 deg., 6 deg., and 9 deg. approaches, and two very different 3 deg. to 9 deg. segmented approaches. The approach profile characteristics are discussed in detail, followed by the noise footprints and handling qualities. Sound exposure levels are also presented on an averaged basis and as a function of the sideline distance for a number of up-range distances from the landing point. A comparison of the noise contour areas is also provided. The results document the variation in tiltrotor noise due to changes in operating condition, and indicate the potential for significant noise reduction using the unique tiltrotor capability of nacelle tilt.

  18. Understanding the Steiner Waldorf Approach: Early Years Education in Practice. Understanding the... Approach

    ERIC Educational Resources Information Center

    Nicol, Janni; Taplin, Jill

    2012-01-01

    Understanding the Steiner Waldorf Approach is a much needed source of information for those wishing to extend and consolidate their understanding of the Steiner Waldorf High Scope Approach. It will enable the reader to analyse the essential elements of the Steiner Waldorf Approach to early childhood and its relationship to quality early years…

  19. Understanding the Montessori Approach: Early Years Education in Practice. Understanding the... Approach

    ERIC Educational Resources Information Center

    Isaacs, Barbara

    2012-01-01

    "Understanding the Montessori Approach" is a much needed source of information for those wishing to extend and consolidate their understanding of the Montessori Approach and how it is used in the teaching and learning of young children. It will enable the reader to analyse the essential elements of this Approach to early childhood and and its…

  20. Eastern and Western Approaches to Medicine

    PubMed Central

    Tsuei, Julia J.

    1978-01-01

    An objective comparison of Eastern and Western approaches to medicine is necessary to further evaluate the validity of Oriental medical techniques such as acupuncture. The development of medicine in Western nations follows the way of hypothetical deduction and the Eastern approach uses the inductive method. The Western approach clearly divides the health from the disease, yet the Eastern approach considers health as a balanced state versus disease as an unbalanced state. The Western approach tends to change the environment and the Eastern way is to prefer to adapt to the environment. There are numerous difficulties in comparing these two approaches. The same terminology may apply to entirely different facts, the teaching and learning methods are quite different, and the evaluation of the treatment is almost not comparable. In order to help understand the Eastern approach better, an understanding is needed of the basic Chinese concepts: the concept of a small universe living in a large universe; the duality concept of yin and yang; the concept of anatomy; the concept of physiology in Chinese medicine—the state of equilibrium expressed by the five elements; the concept of pathophysiology expressed by the external and internal insults; the concept of maintaining and promoting health expressed by the circulation of chi and hsieh; the therapeutic concept in Chinese medicine—the normalization or reestablishment of balance of the body function; the concept of preventive medicine. PMID:664653

  1. System test approach for the SAX satellite

    NASA Technical Reports Server (NTRS)

    Giordano, Pietro; Raimondo, Giacomo; Messidoro, Piero

    1992-01-01

    SAX satellite verification is based on a protoflight approach, in which only one system model is realized at flight standard level, taking into account the utilization of hardware already qualified for other space programs and the necessity to respect the schedule constraints for a scientific objective. In any case, this approach was tailored with some deviations in order to reduce risks inherent in such a choice. The protoflight approach was also pursued at subsystem/unit level in particular for those subsystems and units considered critical from the schedule point of view. Payload Instruments followed the same approach but complete spare units were developed to reduce the risks associated with such an approach. A description of the model philosophy is provided and then, at satellite level, the testing approach and rationale for each model is presented. Finally, a brief description of each test will be given, highlighting objectives, methodologies, and test configurations. Moreover, for the major tests, problems encountered and solutions applied in establishing a correct approach are described.

  2. Overstress and flowstress approaches to dynamic viscoplasticity

    NASA Astrophysics Data System (ADS)

    Partom, Yehuda

    2015-09-01

    Viscoplasticity is mostly modelled by the flowstress approach, where the flowstress (Y) is a function of pressure, temperature, plastic strain and strain rate Y(P,T, ɛp, ɛ˙). For dynamic Viscoplasticity the flowstress approach is used in hydrocodes together with the radial return algorithm, to determine deviatoric stress components in each computational cell and for each time step. The flowstress approach assumes that during plastic loading, the flowstress in stress space follows the current stress point (current Y). Unloading of a computational cell is therefore always elastic. The overstress approach to dynamic viscoplasticity was used in various versions in the 1950s and early 1960s, before the advent of hydrocodes. By the overstress approach a state point may move out of the quasistatic flow surface upon loading, and hence the term overstress. When this happens, the state point tends to fall back (or relax) onto the quasistatic flow surface through plastic flow, and the rate of this relaxation is an increasing function of the amount of overstress. In the paper we first outline in detail how these two approaches to dynamic viscoplasticity work, and then show an example for which the overstress approach has an advantage over the flowstress approach. The example has to do with elastic precursor decay in planar impact, and with the phenomenon of anomalous thermal strengthening, revealed recently in planar impact tests. The overstress approach has an advantage whenever plastic flow during unloading is of importance.

  3. Exploring Mouse Protein Function via Multiple Approaches

    PubMed Central

    Huang, Tao; Kong, Xiangyin; Zhang, Yunhua; Zhang, Ning

    2016-01-01

    Although the number of available protein sequences is growing exponentially, functional protein annotations lag far behind. Therefore, accurate identification of protein functions remains one of the major challenges in molecular biology. In this study, we presented a novel approach to predict mouse protein functions. The approach was a sequential combination of a similarity-based approach, an interaction-based approach and a pseudo amino acid composition-based approach. The method achieved an accuracy of about 0.8450 for the 1st-order predictions in the leave-one-out and ten-fold cross-validations. For the results yielded by the leave-one-out cross-validation, although the similarity-based approach alone achieved an accuracy of 0.8756, it was unable to predict the functions of proteins with no homologues. Comparatively, the pseudo amino acid composition-based approach alone reached an accuracy of 0.6786. Although the accuracy was lower than that of the previous approach, it could predict the functions of almost all proteins, even proteins with no homologues. Therefore, the combined method balanced the advantages and disadvantages of both approaches to achieve efficient performance. Furthermore, the results yielded by the ten-fold cross-validation indicate that the combined method is still effective and stable when there are no close homologs are available. However, the accuracy of the predicted functions can only be determined according to known protein functions based on current knowledge. Many protein functions remain unknown. By exploring the functions of proteins for which the 1st-order predicted functions are wrong but the 2nd-order predicted functions are correct, the 1st-order wrongly predicted functions were shown to be closely associated with the genes encoding the proteins. The so-called wrongly predicted functions could also potentially be correct upon future experimental verification. Therefore, the accuracy of the presented method may be much higher in

  4. Various approaches of teaching veterinary parasitology.

    PubMed

    Gottstein, B; Eckert, J

    2002-10-02

    In this paper, we discuss the advantages and disadvantages of various approaches of teaching veterinary parasitology, including the disciplinary, the problem-oriented and combined approaches. In the disciplinary approach, parasitology is taught in the classical manner as a coherent subject, covering parasite morphology, biology, molecular biology, epidemiology, pathology, immunology, clinical manifestation, diagnosis, therapy, control, and prevention. Problem-oriented teaching approaches the subjects starting from diseases in animal species or from organ systems or other objectives (e.g. food safety); it also tackles training of skills for problem solving and self-learning. Combined approaches include elements of the disciplinary approach and those of other methods. A combined approach of teaching veterinary parasitology, including basic disciplinary teaching of at least 70-90 h, and additional problem-oriented education, was recently proposed in a resolution by the World Association for the Advancement of Veterinary Parasitology [WAAVP News Lett. 5 (1) 3-4]. In 1999, a new curriculum has been established at the Faculty of Veterinary Medicine, University of Berne, originally planned as a combination of organ-focused and problem-based approach. This model was soon identified to cause problems in teaching some disciplines, including infectious diseases. Conversely, the short-term experiences with this combined approach also confirmed some advantages of problem-oriented teaching in other, mainly clinical domains. Nevertheless, closer interdisciplinary contact and collaboration--especially in elective teaching--was enforced between paraclinical and clinical teaching by reforming the curriculum. However, it turned out that large student numbers in relation to the resources of manpower, rooms and finances limited the workability of the curriculum. Therefore, further and probably continuous improvement of the curriculum is necessary.

  5. Design of Quiet Rotorcraft Approach Trajectories

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Burley, Casey L.; Boyd, D. Douglas, Jr.; Marcolini, Michael A.

    2009-01-01

    A optimization procedure for identifying quiet rotorcraft approach trajectories is proposed and demonstrated. The procedure employs a multi-objective genetic algorithm in order to reduce noise and create approach paths that will be acceptable to pilots and passengers. The concept is demonstrated by application to two different helicopters. The optimized paths are compared with one another and to a standard 6-deg approach path. The two demonstration cases validate the optimization procedure but highlight the need for improved noise prediction techniques and for additional rotorcraft acoustic data sets.

  6. [Approaching Physically Inactive Elderly for Physical Activity].

    PubMed

    Allmer, H; Allmer, M; Euskirchen, J; Froböse, I; Wallmann, B; Walter, T; Walschek, R

    2015-09-01

    The majority of elderly persons are still not sufficiently physically active. Therefore the aim of this study was to investigate different approaches (physical activity courses, poster, online-survey) for activating elderly to participate in physical activity. The most effective approach was target group physical activity courses with which higher course participation rates in men as well as in people with lower levels of education were achieved. Referring to the transtheoretical model (TTM) it is necessary for future analyses of target group approaches to consider more intensely the initial motivational position of physically inactive elderly.

  7. The interscrotal approach to inguinoscrotal pathologies

    PubMed Central

    Soualili, Zineddine; Achouri, Djelloul; Haif, Assia; Touabti, Souhem; Yahia, Smain Ait; Benmahmoud, Mahmoud; Choutri, Hichem; Nedjar, Sameh; Mimoune, Malika; Chouaib, Sayah

    2015-01-01

    Objective To determine the efficiency of the interscrotal approach to inguinoscrotal pathologies. Patients and methods We report the use of the interscrotal approach in 21 boys, from September 2012 to November 2013, operated using an interscrotal access through a vertical incision on the median raphe. Results The approach was used for bilateral inguinal hernia (48%), bilateral ectopic testis (19%), torsion of the spermatic cord (19%), testicular biopsy (10%) and webbing of the penis (5%). Conclusion Inter-scrotal access is an option for inguinoscrotal pathologies, with the advantages of a single incision, much less dissection and disruption of tissue, and greater comfort for the ‘day-case’ child. PMID:26413342

  8. Computational approaches to computational aero-acoustics

    NASA Technical Reports Server (NTRS)

    Hardin, Jay C.

    1996-01-01

    The various techniques by which the goal of computational aeroacoustics (the calculation and noise prediction of a fluctuating fluid flow) may be achieved are reviewed. The governing equations for compressible fluid flow are presented. The direct numerical simulation approach is shown to be computationally intensive for high Reynolds number viscous flows. Therefore, other approaches, such as the acoustic analogy, vortex models and various perturbation techniques that aim to break the analysis into a viscous part and an acoustic part are presented. The choice of the approach is shown to be problem dependent.

  9. Evaluation of Resource Acquisition Approaches : Final Report.

    SciTech Connect

    O`Neill, Maura L.; Mortimer, Tom; Palermini, Debbi; Nelson, Kari

    1991-09-12

    Over the last few years, Bonneville has been addressing this need and has developed numerous ways of acquiring resources. Four of these Approaches, the Competitive Acquisition, Billing Credits, and Targeted Acquisition Programs, and the Cowlitz Falls Hydroelectric Project, were the subject of this evaluation project. Each Approach is currently in different stages of a process, and Bonneville felt it was an appropriate time that an evaluation be conducted. The purpose of this evaluation is to analyze the various Approaches` processes, to learn what`s working and what`s not, and to offer recommendations as to how Bonneville might improve their resources acquisition efforts. The evaluation was conducted with no preconceived biases.

  10. Approaching Moons from Resonance via Invariant Manifolds

    NASA Technical Reports Server (NTRS)

    Anderson, Rodney L.

    2012-01-01

    In this work, the approach phase from the final resonance of the endgame scenario in a tour design is examined within the context of invariant manifolds. Previous analyses have typically solved this problem either by using numerical techniques or by computing a catalog of suitable trajectories. The invariant manifolds of a selected set of libration orbits and unstable resonant orbits are computed here to serve as guides for desirable approach trajectories. The analysis focuses on designing an approach phase that may be tied into the final resonance in the endgame sequence while also targeting desired conditions at the moon.

  11. When opportunity meets motivation: Neural engagement during social approach is linked to high approach motivation.

    PubMed

    Radke, Sina; Seidel, Eva-Maria; Eickhoff, Simon B; Gur, Ruben C; Schneider, Frank; Habel, Ute; Derntl, Birgit

    2016-02-15

    Social rewards are processed by the same dopaminergic-mediated brain networks as non-social rewards, suggesting a common representation of subjective value. Individual differences in personality and motivation influence the reinforcing value of social incentives, but it remains open whether the pursuit of social incentives is analogously supported by the neural reward system when positive social stimuli are connected to approach behavior. To test for a modulation of neural activation by approach motivation, individuals with high and low approach motivation (BAS) completed implicit and explicit social approach-avoidance paradigms during fMRI. High approach motivation was associated with faster implicit approach reactions as well as a trend for higher approach ratings, indicating increased approach tendencies. Implicit and explicit positive social approach was accompanied by stronger recruitment of the nucleus accumbens, middle cingulate cortex, and (pre-)cuneus for individuals with high compared to low approach motivation. These results support and extend prior research on social reward processing, self-other distinctions and affective judgments by linking approach motivation to the engagement of reward-related circuits during motivational reactions to social incentives. This interplay between motivational preferences and motivational contexts might underlie the rewarding experience during social interactions.

  12. Integrated Approach to Flight Crew Training

    NASA Technical Reports Server (NTRS)

    Carroll, J. E.

    1984-01-01

    The computer based approach used by United Airlines for flight training is discussed. The human factors involved in specific aircraft accidents are addressed. Flight crew interaction and communication as they relate to training and flight safety are considered.

  13. Approaching the 2015 Arctic Sea Ice Minimum

    NASA Video Gallery

    As the sun sets over the Arctic, the end of this year’s melt season is quickly approaching and the sea ice cover has already shrunk to the fourth lowest in the satellite record. With possibly some ...

  14. Electricity distribution networks: Changing regulatory approaches

    NASA Astrophysics Data System (ADS)

    Cambini, Carlo

    2016-09-01

    Increasing the penetration of distributed generation and smart grid technologies requires substantial investments. A study proposes an innovative approach that combines four regulatory tools to provide economic incentives for distribution system operators to facilitate these innovative practices.

  15. Context vector approach to image retrieval

    NASA Astrophysics Data System (ADS)

    Ren, Clara Z.; Means, Robert W.

    1998-04-01

    HNC developed a unique context vector approach to image retrieval in Image Contrast Addressable Retrieval System. The basis for this approach is the context vector approach to image representation. A context vector is a high dimensional vector of real numbers, derived from a set of features that are useful in discriminating between images in a particular domain. The image features are trained based upon the constrained 2D self-organizing learning law. The image context vector encodes both intra-image features and inter-image relationship. The similarity in the directions of the context vectors of a pair of images indicates their similarity of content. The context vector approach to image representation simplifies the image and retrieval indexing problem because simple Euclidean distance measurements between sets of context vectors are used as a measure of similarity.

  16. Approach to low back pain - acupuncture.

    PubMed

    Ee, Carolyn

    2014-05-01

    This article forms part of our allied health series for 2014, which aims to provide information about the management approach of different allied health professionals, using the case example of uncomplicated, mechanical low back pain.

  17. A Colloquial Approach: An Active Learning Technique.

    ERIC Educational Resources Information Center

    Arce, Pedro

    1994-01-01

    Addresses the problem of the effectiveness of teaching methodologies on fundamental engineering courses such as transport phenomena. Recommends the colloquial approach, an active learning strategy, to increase student involvement in the learning process. (ZWH)

  18. Design and Build Approaches for Green Streets

    EPA Pesticide Factsheets

    This page serves to discuss the concept behind G3's innovative design build strategy. Design build offers a more comprehensive and streamlined approach to project construction and management compared to my traditional methods and is highly encouraged

  19. A General Synthetic Approach to Functionalized Dihydrooxepines

    PubMed Central

    Nicolaou, K. C.; Yu, Ruocheng; Shi, Lei; Cai, Quan; Lu, Min; Heretsch, Philipp

    2013-01-01

    A three-step sequence to access functionalized 4,5-dihydrooxepines from cyclohexenones has been developed. This approach features a regioselective Baeyer–Villiger oxidation and subsequent functionalization via the corresponding enol phosphate intermediate. PMID:23550898

  20. A perturbative approach to central exclusive production

    NASA Astrophysics Data System (ADS)

    Harland-Lang, L. A.; Khoze, V. A.; Ryskin, M. G.

    2015-02-01

    We review some selected results within the Durham model of central exclusive production. We present a detailed discussion of this theoretical approach for modeling exclusive processes and we briefly review some of its phenomenological applications.

  1. A Graphical Approach to Relatedness Inference

    PubMed Central

    Almudevar, Anthony

    2007-01-01

    The estimation of relatedness structure in natural populations using molecular marker data has become an important tool in population biology, resulting in a variety of estimation procedures for specific sampling scenarios. In this article a general approach is proposed, in which the detailed relationship structure, typically a pedigree graph or partition, is considered to be the object of inference. This makes available tools used in complex model selection theory which have demonstrated effectiveness. An important advantage of this approach is that it permits a fully Bayesian approach to the problem, providing a principled and accessible way to measure statistical error. The approach is demonstrated by applying the minimum description length principle. This technique is used in model selection to provide a rational way of comparing models of varying complexity. We show how the resulting score may be interpreted and applied as a Bayesian posterior density. PMID:17169391

  2. Current Cognitive Approaches to Childhood Psychopathology.

    ERIC Educational Resources Information Center

    Garfield, Sol L., Ed.

    1984-01-01

    Presents six developmentally oriented articles on childhood psychopathology. Reviews research dealing with autism, social isolation, interpersonal understanding, sociomoral reasoning, cognitive controls, and aggression and includes an overview of progress and problems in the cognitive approach to clinical child psychology. (JAC)

  3. Crime and Justice: Taking a Futuristic Approach.

    ERIC Educational Resources Information Center

    Stephens, Gene; Tafoya, William L.

    1985-01-01

    How to apply futuristic approaches to crime and justice in an effort to prevent crime and deal more effectively with offenders is described. Planning, brainstorming, using the Delphi method, and opinion polling are discussed. (Author/RM)

  4. Taking a Holistic Approach to Retention.

    ERIC Educational Resources Information Center

    Fields, Cheryl D.

    2002-01-01

    Describes how, at the University of Kansas, many students of color are excelling at a rate that has outpaced their peers. Campus officials credit the HAWK Link program and its comprehensive approach to retention. (EV)

  5. Red Shifts with Obliquely Approaching Light Sources.

    ERIC Educational Resources Information Center

    Head, C. E.; Moore-Head, M. E.

    1988-01-01

    Refutes the Doppler effect as the explanation of large red shifts in the spectra of distant galaxies and explains the relativistic effects in which the light sources approach the observer obliquely. Provides several diagrams and graphs. (YP)

  6. Approaches to lunar base life support

    NASA Technical Reports Server (NTRS)

    Brown, M. F.; Edeen, M. A.

    1990-01-01

    Various approaches to reliable, low maintenance, low resupply regenerative long-term life support for lunar base application are discussed. The first approach utilizes Space Station Freedom physiochemical systems technology which has closed air and water loops with approximately 99 and 90 percent closure respectively, with minor subsystem changes to the SSF baseline improving the level of water resupply for the water loop. A second approach would be a physiochemical system, including a solid waste processing system and improved air and water loop closure, which would require only food and nitrogen for resupply. A hybrid biological/physiochemical life support system constitutes the third alternative, incorporating some level of food production via plant growth into the life support system. The approaches are described in terms of mass, power, and resupply requirements; and the potential evolution of a small, initial outpost to a large, self-sustaining base is discussed.

  7. A SYSTEMS BIOLOGY APPROACH TO DEVELOPMENTAL TOXICOLOGY

    EPA Science Inventory

    Abstract
    Recent advances in developmental biology have yielded detailed models of gene regulatory networks (GRNs) involved in cell specification and other processes in embryonic differentiation. Such networks form the bedrock on which a systems biology approach to developme...

  8. The Limits to Adaptation; A Systems Approach

    EPA Science Inventory

    The Limits to Adaptation: A Systems Approach. The ability to adapt to climate change is delineated by capacity thresholds, after which climate damages begin to overwhelm the adaptation response. Such thresholds depend upon physical properties (natural processes and engineering...

  9. The transcaruncular approach: surgical anatomy and technique.

    PubMed

    Goldberg, Robert A; Mancini, Ronald; Demer, Joseph L

    2007-01-01

    With a detailed understanding of the pertinent surgical anatomy, the transcaruncular approach provides safe access and excellent exposure of the medial orbit and orbital apex. We herein describe our technique of the transcaruncular approach and delineate the pertinent associated surgical anatomy via dissection, magnetic resonance imaging, and histologic examination. The isolated transcaruncular approach provides exposure of the medial orbital floor from the region of the maxilloethmoidal strut to the orbital roof area superior to the frontoethmoidal suture. When combined with an inferior fornix incision, the transcaruncular approach allows for continuous exposure from the frontozygomatic suture laterally to the frontoethmoidal suture medially. Attention to anatomical details promotes creation of an effective and safe caruncular incision. The conjunctival incision should be ample. The orbital septum should be carefully dissected from the posterior surface of the Horner muscle to minimize fat spillage, and the periosteum should be opened widely at the beginning of surgery.

  10. A "Bioethics" Approach to Teaching Health Law.

    ERIC Educational Resources Information Center

    Capron, Alexander Morgan

    1988-01-01

    The reasons for offering a course in bioethics to law students and some approaches to take in addressing controversial issues are examined. The use of hypothetical vs. real cases, emphasis on clinical problems, and overall course objectives are discussed. (MSE)

  11. Three Approaches to Writing the First Poem.

    ERIC Educational Resources Information Center

    Rodriguez, William Robert

    1985-01-01

    Suggests that by using the three approaches to writing the first poem--breath-grouping, prosepoetry, and the repeater--students will conceptualize and practice some of the possible forms of contemporary poetry. (EL)

  12. An Approach to Institutional Decision-Making.

    ERIC Educational Resources Information Center

    Doyle, K. J.

    1981-01-01

    Three approaches to institutional planning are discussed: process, quantitative, and contingency. Features and problems of each are examined. All three have been used successfully in higher education, usually in partial rather than complete form. (MSE)

  13. Ecological Approaches to Understanding Human Crowding.

    ERIC Educational Resources Information Center

    Baron, Reuben M.

    1979-01-01

    Characteristics of the ecological approach to perception are presented. The affordance concept and its relevance is emphasized. Human crowding is discussed in affordance terms. There is a comparison given between present affordance analysis and ecological analysis. (Author/SA)

  14. DNAPL Remediation: Selected Projects Approaching Regulatory Closure

    EPA Pesticide Factsheets

    This paper is a status update on the use of DNAPL source reduction remedial technologies, and provides information about recent projects where regulatory closure has been reached or projects are approaching regulatory closure, following source reduction.

  15. Downhill simplex approach for vehicle headlights detection

    NASA Astrophysics Data System (ADS)

    Kang, Ho-Joong; Kim, Ho-Kun; Oh, Il-Whan; Choi, Kyoung-Ho

    2014-03-01

    Nighttime vehicle detection is an essential problem to be solved in the development of highway surveillance systems that provide information about the vehicle speed, traffic volume, and traffic jams, and so on. In this paper, a novel downhill simplex approach for vehicle headlights detection is presented. In the proposed approach, a rough position of vehicle headlights is detected first. Then, a downhill simplex optimization approach is adopted to find the accurate location of vehicle headlights. For the optimization process, a novel cost function is designed and various headlights are evaluated for possible headlight positions on the detected vehicles, locating an optimal headlight position. Simulation results are provided to show the robustness of the proposed approach for headlights detection.

  16. Marketing in Admissions: The Information System Approach.

    ERIC Educational Resources Information Center

    Wofford, O. Douglas; Timmerman, Ed

    1982-01-01

    A marketing information system approach for college admissions is outlined that includes objectives, information needs and sources, a data collection format, and information evaluation. Coordination with other institutional information systems is recommended. (MSE)

  17. Nanotechnology based approaches in cancer therapeutics

    NASA Astrophysics Data System (ADS)

    Kumer Biswas, Amit; Reazul Islam, Md; Sadek Choudhury, Zahid; Mostafa, Asif; Fahim Kadir, Mohammad

    2014-12-01

    The current decades are marked not by the development of new molecules for the cure of various diseases but rather the development of new delivery methods for optimum treatment outcome. Nanomedicine is perhaps playing the biggest role in this concern. Nanomedicine offers numerous advantages over conventional drug delivery approaches and is particularly the hot topic in anticancer research. Nanoparticles (NPs) have many unique criteria that enable them to be incorporated in anticancer therapy. This topical review aims to look at the properties and various forms of NPs and their use in anticancer treatment, recent development of the process of identifying new delivery approaches as well as progress in clinical trials with these newer approaches. Although the outcome of cancer therapy can be increased using nanomedicine there are still many disadvantages of using this approach. We aim to discuss all these issues in this review.

  18. Kinetics and Mechanism--A Games Approach.

    ERIC Educational Resources Information Center

    Harsch, Gunther

    1984-01-01

    Proposes an approach to chemical kinetics and mechanism using statistical games, illustrating its use in monomolecular, catalytic, autocatalytic, consecutive, and equilibrium reactions. Major features of the games are also outlined and discussed. (JN)

  19. The virtue ethics approach to bioethics.

    PubMed

    Holland, Stephen

    2011-05-01

    This paper discusses the viability of a virtue-based approach to bioethics. Virtue ethics is clearly appropriate to addressing issues of professional character and conduct. But another major remit of bioethics is to evaluate the ethics of biomedical procedures in order to recommend regulatory policy. How appropriate is the virtue ethics approach to fulfilling this remit? The first part of this paper characterizes the methodology problem in bioethics in terms of diversity, and shows that virtue ethics does not simply restate this problem in its own terms. However, fatal objections to the way the virtue ethics approach is typically taken in bioethics literature are presented in the second section of the paper. In the third part, a virtue-based approach to bioethics that avoids the shortcomings of the typical one is introduced and shown to be prima facie plausible. The upshot is an inviting new direction for research into bioethics' methodology.

  20. An economic approach to environmental indices

    EPA Science Inventory

    This study uses the directional output distance function from economic productivity theory as an alternative approach to environmental index construction. We use the directional output distance function to aggregate multiple environmental objectives into one measure of environme...