A thermodynamic model of hemoglobin suitable for physiological applications

1990 ◽  
Vol 258 (3) ◽  
pp. C563-C577 ◽  
Author(s):  
T. Yoshida ◽  
M. Dembo
Keyword(s):  
Binding Sites ◽  
Electrostatic Interactions ◽  
Mean Field ◽  
Quantitative Model ◽  
Confidence Limits ◽  
Efficient Computation ◽  
Ligand Binding Sites ◽  
The Mean ◽  
Field Formalism ◽  
Good Agreement

We propose a quantitative model of the thermodynamics of hemoglobin in contact with its five major ligands (O2, CO2, Cl-, 2,3-bisphosphoglycerate, and H+). Our model incorporates the two-state formalism of J. Monod, J. Wyman, and J.P. Changeux (J. Mol. Biol. 12: 88-118, 1965) for treatment of quanternary transitions and also the mean field formalism of K. Linderstrom-Lang (C. R. Trav. Lab. Carlsberg Ser. Chim. 15: 1-30, 1924) for treatment of electrostatic interactions. On the basis of this approach, we develop an algorithm for the efficient computation of observable quantities, such as the occupancy of various ligand binding sites, and an objective statistical procedure for determining both maximum likelihood values and confidence limits of all the intrinsic thermodynamic parameters of hemoglobin. Finally, we show that the predictions of our theory are in good agreement with independent experimental observations.

scholarly journals Magnetocaloric Effect in Nanosystems Based on Ferromagnets with Different Curie Temperatures

2021 ◽  
Vol 132 (1) ◽  
pp. 79-93
Author(s):  
M. A. Kuznetsov ◽  
A. B. Drovosekov ◽  
A. A. Fraerman
Keyword(s):  
Field Theory ◽  
Magnetocaloric Effect ◽  
Landau Theory ◽  
Mean Field Theory ◽  
Mean Field ◽  
Maxwell Relation ◽  
Magnetic Cooling ◽  
The Mean ◽  
Curie Temperatures ◽  
Good Agreement

Abstract The magnetocaloric effect in nanosystems based on exchange-coupled ferromagnets with different Curie temperatures is calculated within the mean-field theory. Good agreement between the results of the mean-field theory and the Landau theory, valid near the critical phase transition temperature, is demonstrated for a flat-layered Fe/Gd/Fe structure. We show that a high magnetic cooling efficiency in this system is attainable in principle and prove the validity of the Maxwell relation, enabling an experimental verification of the predictions made. The theory developed for flat-layered structures is generalized to a granular medium.

On: “Stratigraphic filter theory: Combined effects of parallel bedding and random inhomogeneities” by I. Lerche (GEOPHYSICS, 51, 1531–1537, August 1986).

Geophysics ◽  
1988 ◽  
Vol 53 (7) ◽  
pp. 995-997 ◽  
Author(s):  
Ru‐Shan Wu
Keyword(s):  
Incident Wave ◽  
Random Media ◽  
Seismic Waves ◽  
Mean Field ◽  
Field Approach ◽  
Scattering Attenuation ◽  
Amplitude Attenuation ◽  
Validity Condition ◽  
The Mean ◽  
Field Formalism

In the paper by Lerche (hereafter referred to as Lerche 86), the author compared his formula of effective attenuation (42) based on the mean field attenuation with formula (41), attributed to Wu (1982a), and claimed that Wu’s formula “explicitly assumed that the Born approximation is valid (i.e., that the scattering by the randomly sited centers is from the unperturbed incident wave with no modification to the wave from previous scattering),” while in his result “the modification to the incident wave is taken into account through the statistically sharp mean field” and therefore is “more correct.” However, neither the statement about the validity condition of Wu’s formula not the author’s formula (42) from the mean field approach is correct. In fact, the mean field formalism, when improperly applied to amplitude attenuation, can generate physically meaningless results. The impotence and fallacy of the mean field formalism in dealing with amplitude attenuation in 3-D random media have been recognized since the early 1980s (Wu, 1980, 1982a, b; Sato, 1982a, b). This recognition and the developments thereafter can be considered as one of the major advances in the field of scattering attenuation of seismic waves (Herraiz and Espinosa, 1987; Wu, 1987). Retreat from this advance seems injudicious and illogical. Therefore, I would like to take this opportunity to clarify some basic problems of scattering attenuation.

The nuclear relaxation rate for the itinerant-electron antiferromagnet

1982 ◽  
Vol 60 (5) ◽  
pp. 649-653 ◽  
Author(s):  
M. Crişan ◽  
Zs. Gulácsi
Keyword(s):  
Field Theory ◽  
Relaxation Rate ◽  
Mean Field Theory ◽  
Mean Field ◽  
Band Model ◽  
Itinerant Electron ◽  
Nuclear Relaxation ◽  
The Mean ◽  
Two Band Model ◽  
Good Agreement

The relaxation rate in the nuclear magnetic resonance of the itinerant-electron antiferromagnet was calculated as a function of temperature. A good agreement with the experimental results obtained on CrB2 has been observed. The two band model for the itinerant-electron antiferromagnet for T < TN (TN is the critical temperature) and the mean field theory for the critical region have been used to calculate [Formula: see text] as a function of temperature.

Magneto—Optical Properties of Amorphous TbFe Alloys

1985 ◽  
Vol 58 ◽  
Author(s):  
M. Mansuripur ◽  
M. Ruane ◽  
P. Wolniansky ◽  
S. Chase ◽  
R. Rosenvold
Keyword(s):  
Mean Field ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Field Approximation ◽  
Anisotropy Energy ◽  
Optical Methods ◽  
Mean Field Approximation ◽  
Kerr Rotation ◽  
The Mean ◽  
Good Agreement

ABSTRACTHysteresis loops and anisotropy energy constants are measured in a magneto—optical system that combines Kerr rotation and ellipticity to enhance signal strength. Temperature dependence of the polar Kerr effect is compared with the magnetization of the iron subnetwork in the mean—field approximation and good agreement is obtained. Perpendicular magnetic anisotropy is studied by magneto—optical methods, yielding the first two coefficients of the series expansion of anisotropy energy in terms of the angleof deviation from the easy axis.

scholarly journals Investigating dirty crossover through fidelity susceptibility and density of states

2014 ◽  
Vol 28 (14) ◽  
pp. 1450083 ◽  
Author(s):  
Ayan Khan ◽  
Saurabh Basu ◽  
B. Tanatar
Keyword(s):  
Phase Transition ◽  
Density Of States ◽  
Quantum Phase Transition ◽  
Line Shape ◽  
Mean Field ◽  
Disorder Strength ◽  
Statistical Tools ◽  
The Mean ◽  
Field Formalism ◽  
Skewness And Kurtosis

We investigate the BCS–BEC crossover in an ultracold atomic gas in the presence of disorder. The disorder is incorporated in the mean-field formalism through Gaussian fluctuations. We observe evolution to an asymmetric line-shape of fidelity susceptibility (FS) as a function of interaction coupling with increasing disorder strength which may point to an impending quantum phase transition (QPT). The asymmetric line-shape is further analyzed using the statistical tools of skewness and kurtosis. We extend our analysis to density of states (DOS) for a better understanding of the crossover in the disordered environment.

Strong Correlation of the Vacuum in Relativistic Mean Field Theory

1997 ◽  
Vol 06 (02) ◽  
pp. 307-322 ◽  
Author(s):  
P. K. Panda ◽  
S. K. Patra ◽  
J. Reinhardt ◽  
J. Maruhn ◽  
H. Stöcker ◽  
...  
Keyword(s):  
Field Theory ◽  
Mean Field Theory ◽  
Mean Field ◽  
High Density ◽  
Relativistic Nucleus ◽  
Relativistic Mean Field ◽  
Scaling Procedure ◽  
The Mean ◽  
Field Formalism ◽  
Very High

We study the strong hadronic vacuum correlation in the vicinity of a nucleus using the relativistic mean field formalism. It is particularly pronounced for higher nuclear densities as occurring in relativistic nucleus-nucleus collisions. The high density scenario in the mean field theory is achieved by a scaling procedure in the density and radius. The production of anti-baryon clusters is predicted for very high density and temperature, and the possible experimental investigation of such antibaryon cluster production is also discussed.

scholarly journals A state-dependent mean-field formalism to model different activity states in conductance based networks of spiking neurons

2019 ◽  
Author(s):  
Cristiano Capone ◽  
Matteo di Volo ◽  
Alberto Romagnoni ◽  
Maurizio Mattia ◽  
Alain Destexhe
Keyword(s):  
Population Dynamics ◽  
High Performance ◽  
Large Scale ◽  
Mean Field ◽  
Analytic Solutions ◽  
Slow Oscillations ◽  
State Dependent ◽  
The Mean ◽  
Field Formalism ◽  
High Performance Computers

AbstractHigher and higher interest has been shown in the recent years to large scale spiking simulations of cerebral neuronal networks, coming both from the presence of high performance computers and increasing details in the experimental observations. In this context it is important to understand how population dynamics are generated by the designed parameters of the networks, that is the question addressed by mean field theories. Despite analytic solutions for the mean field dynamics has already been proposed generally for current based neurons (CUBA), the same for more realistic neural properties, such as conductance based (COBA) network of adaptive exponential neurons (AdEx), a complete analytic model has not been achieved yet. Here, we propose a novel principled approach to map a COBA on a CUBA. Such approach provides a state-dependent approximation capable to reliably predict the firing rate properties of an AdEx neuron with non-instantaneous COBA integration. We also applied our theory to population dynamics, predicting the dynamical properties of the network in very different regimes, such as asynchronous irregular (AI) and synchronous irregular (SI) (slow oscillations, SO).This results show that a state-dependent approximation can be successfully introduced in order to take into account the subtle effects of COBA integration and to deal with a theory capable to correctly predicts the activity in regimes of alternating states like slow oscillations.

scholarly journals Mean-field parameters of some PrxTb(1-x)Al2 compounds found via searching for the best magnetic heat capacity fitting

2021 ◽  
Vol 2090 (1) ◽  
pp. 012081
Author(s):  
J. C. G. Tedesco ◽  
V.J. Monteiro ◽  
A. M. G. Carvalho ◽  
L.P. Cardoso ◽  
A. A. Coelho
Keyword(s):  
Experimental Data ◽  
Heat Capacity ◽  
Magnetocaloric Effect ◽  
Mean Field ◽  
Heat Capacities ◽  
Field Approach ◽  
Physical Limitations ◽  
The Mean ◽  
Good Agreement

Abstract Simulations of the magnetic heat capacity of some (Pr, Tb)Al2 compounds were performed using the mean-field approach. The developed routine aims to optimize the set of mean-field parameters. The proposed algorithm calculates the sum of squared differences between the experimental points and the simulated curve and then changes the parameters in order to minimize this sum. This searching leads to consistent values that can reproduce the experimental data. The parameters found in this work reproduced the heat capacities curves of the PrxTb(1−x)Al2 compounds, x=0.25, x=0.50 and x=0.75, with good agreement. The physical limitations of the mean-field approach do not preclude analysing the results. These parameters are important because they can help to understand and calculate the magnetocaloric effect these materials can present.

scholarly journals Angular momentum and parity projected multidimensionally constrained relativistic Hartree-Bogoliubov model

2021 ◽  
Author(s):  
Kun Wang ◽  
Bingnan Lu
Keyword(s):  
Angular Momentum ◽  
Equilateral Triangle ◽  
Nuclear Physics ◽  
Mean Field ◽  
Fundamental Importance ◽  
Rigid Rotor ◽  
Angular Momentum Projection ◽  
The Mean ◽  
Moment Constraint ◽  
Good Agreement

Abstract The nuclear deformations are of fundamental importance in nuclear physics. Recently we developed a multi-dimensionally constrained relativistic Hartree-Bogoliubov (MDCRHB) model, in which all multipole deformations respecting the $V_4$ symmetry can be considered self-consistently. In this work we extend this model by incorporating the angular momentum projection (AMP) and parity projection (PP) to restore the rotational and parity symmetries broken in the mean-field level. This projected-MDCRHB (p-MDCRHB) model enables us to connect certain nuclear spectra to exotic intrinsic shapes such as triangle or tetrahedron. We present the details of the method and an exemplary calculation for $^{12}$C. We develop a triangular moment constraint to generate the triangular configurations consisting of three $\alpha$ clusters arranged as an equilateral triangle. The resulting $^{12}$C spectra are consistent with that from a triangular rigid rotor for large separations between the $\alpha$ clusters. We also calculate the $B(E2)$ and $B(E3)$ values for low-lying states and find good agreement with the experiments.

Modeling the spread of an epidemic in presence of vaccination using cellular automata

2022 ◽  
Author(s):  
Agniva Datta ◽  
Muktish Acharyya
Keyword(s):  
Cellular Automata ◽  
Lattice Model ◽  
Present Model ◽  
Mean Field ◽  
Sir Model ◽  
Linear Behavior ◽  
Basic Goal ◽  
Ca Model ◽  
The Mean ◽  
Good Agreement

The results of Kermack–McKendrick SIR model are planned to be reproduced by cellular automata (CA) lattice model. The CA algorithms are proposed to study the model of an epidemic, systematically. The basic goal is to capture the effects of spreading of infection over a scale of length. This CA model can provide the rate of growth of the infection over the space which was lacking in the mean-field like susceptible-infected-removed (SIR) model. The motion of the circular front of an infected cluster shows a linear behavior in time. The correlation of a particular site to be infected with respect to the central site is also studied. The outcomes of the CA model are in good agreement with those obtained from SIR model. The results of vaccination have been also incorporated in the CA algorithm with a satisfactory degree of success. The advantage of the present model is that it can shed a considerable amount of light on the physical properties of the spread of a typical epidemic in a simple, yet robust way.

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