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Steven A Balbus - One of the best experts on this subject based on the ideXlab platform.

  • simplified derivation of the gravitational wave stress tensor from the linearized einstein field equations
    Proceedings of the National Academy of Sciences of the United States of America, 2016
    Co-Authors: Steven A Balbus
    Abstract:

    Abstract A conserved stress energy tensor for weak field gravitational waves propagating in vacuum is derived directly from the linearized general relativistic wave equation alone, for an arbitrary gauge. In any harmonic gauge, the form of the tensor leads directly to the Classical Expression for the outgoing wave energy. The method described here, however, is a much simpler, shorter, and more physically motivated approach than is the customary procedure, which involves a lengthy and cumbersome second-order (in wave-amplitude) calculation starting with the Einstein tensor. Our method has the added advantage of exhibiting the direct coupling between the outgoing wave energy flux and the work done by the gravitational field on the sources. For nonharmonic gauges, the directly derived wave stress tensor has an apparent index asymmetry. This coordinate artifact may be straightforwardly removed, and the symmetrized (still gauge-invariant) tensor then takes on its widely used form. Angular momentum conservation follows immediately. For any harmonic gauge, however, the stress tensor found is manifestly symmetric from the start, and its derivation depends, in its entirety, on the structure of the linearized wave equation.

  • gravitational wave stress tensor from the linearised field equations
    arXiv: General Relativity and Quantum Cosmology, 2016
    Co-Authors: Steven A Balbus
    Abstract:

    A conserved stress energy tensor for weak field gravitational waves in standard general relativity is derived directly from the linearised wave equation alone, for an arbitrary gauge. The form of the tensor leads directly to the Classical Expression for the outgoing wave energy in any harmonic gauge. The method described here, however, is a much simpler, shorter, and more physically motivated approach than is the customary procedure, which involves a lengthy and cumbersome second-order (in wave-amplitude) calculation starting with the Einstein tensor. Our method has the added advantage of exhibiting the direct coupling between the outgoing energy flux in gravitational waves and the work done by the gravitational field on the sources. For nonharmonic gauges, the derived wave stress tensor has an index asymmetry. This coordinate artefact may be removed by techniques similar to those used in Classical electrodynamics (where this issue also arises), but only by appeal to a more lengthy calculation. For any harmonic gauge, however, the stress tensor is manifestly symmetric and its derivation depends, in its entirety, on the first-order wave equation.

Alexander Pushin - One of the best experts on this subject based on the ideXlab platform.

  • Development of Wolffia arrhiza as a Producer for Recombinant Human Granulocyte Colony-Stimulating Factor
    Frontiers Media S.A., 2018
    Co-Authors: Pavel Khvatkov, Alexsey Firsov, Anastasiya Shvedova, Lyubov Shaloiko, Oleg Kozlov, Mariya Chernobrovkina, Alexander Pushin
    Abstract:

    To date, the Expression of recombinant proteins in transgenic plants is becoming a powerful alternative to Classical Expression methods. Special efforts are directed to the development of contained cultivation systems based on cell culture or rhyzosecretion, which reliably prevents the heterologous DNA releasing into the environment. A promising object for the development of such systems is the tiny aquatic plant of Wolffia arrhiza, which can be used as a dipped culture in bioreactors. Herein we have expressed the human granulocyte colony-stimulating factor (hG-CSF) in nuclear-transformed Wolffia. The nucleotide sequence of hG-CSF was optimized for Expression in Wolffia and cloned into the vector pCamGCSF downstream of double CaMV 35S promoter. Wolffia plants were successfully transformed and 34 independent transgenic lines with hG-CSF gene were obtained, PCR and Southern blot analysis confirmed the transgenic origin of these lines. Western blot analysis revealed accumulation of the target protein in 33 transgenic lines. Quantitative ELISA of protein extracts from these lines showed hG-CSF accumulation up to 35.5 mg/kg of Wolffia fresh weight (0.194% of total soluble protein). This relatively high yield holds promise for the development of Wolffia-based Expression system in strictly controlled format to produce various recombinant proteins

  • Table_1_Development of Wolffia arrhiza as a Producer for Recombinant Human Granulocyte Colony-Stimulating Factor.DOCX
    2018
    Co-Authors: Pavel Khvatkov, Alexsey Firsov, Anastasiya Shvedova, Lyubov Shaloiko, Oleg Kozlov, Mariya Chernobrovkina, Alexander Pushin, Inna Chaban, Irina Tarasenko, Sergey Dolgov
    Abstract:

    To date, the Expression of recombinant proteins in transgenic plants is becoming a powerful alternative to Classical Expression methods. Special efforts are directed to the development of contained cultivation systems based on cell culture or rhyzosecretion, which reliably prevents the heterologous DNA releasing into the environment. A promising object for the development of such systems is the tiny aquatic plant of Wolffia arrhiza, which can be used as a dipped culture in bioreactors. Herein we have expressed the human granulocyte colony-stimulating factor (hG-CSF) in nuclear-transformed Wolffia. The nucleotide sequence of hG-CSF was optimized for Expression in Wolffia and cloned into the vector pCamGCSF downstream of double CaMV 35S promoter. Wolffia plants were successfully transformed and 34 independent transgenic lines with hG-CSF gene were obtained, PCR and Southern blot analysis confirmed the transgenic origin of these lines. Western blot analysis revealed accumulation of the target protein in 33 transgenic lines. Quantitative ELISA of protein extracts from these lines showed hG-CSF accumulation up to 35.5 mg/kg of Wolffia fresh weight (0.194% of total soluble protein). This relatively high yield holds promise for the development of Wolffia-based Expression system in strictly controlled format to produce various recombinant proteins.

Pavel Khvatkov - One of the best experts on this subject based on the ideXlab platform.

  • Development of Wolffia arrhiza as a Producer for Recombinant Human Granulocyte Colony-Stimulating Factor
    Frontiers Media S.A., 2018
    Co-Authors: Pavel Khvatkov, Alexsey Firsov, Anastasiya Shvedova, Lyubov Shaloiko, Oleg Kozlov, Mariya Chernobrovkina, Alexander Pushin
    Abstract:

    To date, the Expression of recombinant proteins in transgenic plants is becoming a powerful alternative to Classical Expression methods. Special efforts are directed to the development of contained cultivation systems based on cell culture or rhyzosecretion, which reliably prevents the heterologous DNA releasing into the environment. A promising object for the development of such systems is the tiny aquatic plant of Wolffia arrhiza, which can be used as a dipped culture in bioreactors. Herein we have expressed the human granulocyte colony-stimulating factor (hG-CSF) in nuclear-transformed Wolffia. The nucleotide sequence of hG-CSF was optimized for Expression in Wolffia and cloned into the vector pCamGCSF downstream of double CaMV 35S promoter. Wolffia plants were successfully transformed and 34 independent transgenic lines with hG-CSF gene were obtained, PCR and Southern blot analysis confirmed the transgenic origin of these lines. Western blot analysis revealed accumulation of the target protein in 33 transgenic lines. Quantitative ELISA of protein extracts from these lines showed hG-CSF accumulation up to 35.5 mg/kg of Wolffia fresh weight (0.194% of total soluble protein). This relatively high yield holds promise for the development of Wolffia-based Expression system in strictly controlled format to produce various recombinant proteins

  • Table_1_Development of Wolffia arrhiza as a Producer for Recombinant Human Granulocyte Colony-Stimulating Factor.DOCX
    2018
    Co-Authors: Pavel Khvatkov, Alexsey Firsov, Anastasiya Shvedova, Lyubov Shaloiko, Oleg Kozlov, Mariya Chernobrovkina, Alexander Pushin, Inna Chaban, Irina Tarasenko, Sergey Dolgov
    Abstract:

    To date, the Expression of recombinant proteins in transgenic plants is becoming a powerful alternative to Classical Expression methods. Special efforts are directed to the development of contained cultivation systems based on cell culture or rhyzosecretion, which reliably prevents the heterologous DNA releasing into the environment. A promising object for the development of such systems is the tiny aquatic plant of Wolffia arrhiza, which can be used as a dipped culture in bioreactors. Herein we have expressed the human granulocyte colony-stimulating factor (hG-CSF) in nuclear-transformed Wolffia. The nucleotide sequence of hG-CSF was optimized for Expression in Wolffia and cloned into the vector pCamGCSF downstream of double CaMV 35S promoter. Wolffia plants were successfully transformed and 34 independent transgenic lines with hG-CSF gene were obtained, PCR and Southern blot analysis confirmed the transgenic origin of these lines. Western blot analysis revealed accumulation of the target protein in 33 transgenic lines. Quantitative ELISA of protein extracts from these lines showed hG-CSF accumulation up to 35.5 mg/kg of Wolffia fresh weight (0.194% of total soluble protein). This relatively high yield holds promise for the development of Wolffia-based Expression system in strictly controlled format to produce various recombinant proteins.

Tasawar Hayat - One of the best experts on this subject based on the ideXlab platform.

  • on doubly stratified chemically reactive flow of powell eyring liquid subject to non fourier heat flux theory
    Results in physics, 2017
    Co-Authors: Tasawar Hayat, M Waqas, M Zubair, A Alsaedi, Muhammad Ayub
    Abstract:

    Abstract This investigation addresses the chemical reaction and double stratification effects in the flow induced by a nonlinear stretching surface with variable thickness. Flow formulation is developed using rheological Expressions of Eyring–Powell liquid. Salient features of heat transfer are examined by considering non-Fourier heat flux model. Formulation is arranged for variable thermal conductivity. Flux model under consideration is the generalized form of Fourier’s Classical Expression with thermal relaxation time. Ordinary differential systems are obtained through implementation of appropriate transformations. Convergent series solutions are constructed. Non-dimensional velocity, temperature, concentration, skin friction and Sherwood number are displayed and discussed. It is anticipated that thermal and concentration stratified parameters decay the temperature and concentration respectively.

  • on 2d stratified flow of an oldroyd b fluid with chemical reaction an application of non fourier heat flux theory
    Journal of Molecular Liquids, 2016
    Co-Authors: Tasawar Hayat, M Waqas, S A Shehzad
    Abstract:

    Abstract This research work explores the double stratified flow of an Oldroyd-B liquid induced by linear stretching surface with first order chemical reaction. Characteristics of heat transfer are investigated by considering non-Fourier heat flux model. Formulation is arranged for variable thermal conductivity. Flux model under consideration is the modified form of Fourier's Classical Expression which studies the fascinating characteristic of thermal relaxation time. Implementation of appropriate transformations yields ordinary differential systems which are then computed through homotopic procedure. Impacts of various sundry parameters on the non-dimensional velocity, temperature, concentration and Sherwood number are scrutinized. Moreover it is seen that temperature distribution has opposite behavior for thermal relaxation time and variable thermal conductivity parameter.

Thomas Keyes - One of the best experts on this subject based on the ideXlab platform.

  • a time correlation function theory of two dimensional infrared spectroscopy with applications to liquid water
    Journal of Chemical Physics, 2004
    Co-Authors: Russell Devane, Christine Neipert, Angela Perry, Christina Ridley, Brian Space, Thomas Keyes
    Abstract:

    A theory describing the third-order response function R(3)(t1,t2,t3), which is associated with two-dimensional infrared (2DIR) spectroscopy, has been developed. R(3) can be written as sums and differences of four distinct quantum mechanical dipole (multi)time correlation functions (TCF’s), each with the same Classical limit; the combination of TCF’s has a leading contribution of order ℏ3 and thus there is no obvious Classical limit that can be written in terms of a TCF. In order to calculate the response function in a form amenable to Classical mechanical simulation techniques, it is rewritten approximately in terms of a single Classical TCF, BR(t1,t2,t3)=〈μj(t2+t1)μi(t3+t2+t1)μk(t1)μl(0)〉, where the subscripts denote the Cartesian dipole directions. The response function is then given, in the frequency domain, as the Fourier transform of a Classical TCF multiplied by frequency factors. This Classical Expression can then further be quantum corrected to approximate the true response function, although for ...