scholarly journals Bell-shaped dose response for a system with no IFFLs

2020 ◽  
Author(s):  
Eduardo D. Sontag
Keyword(s):  
Steady State ◽  
T Cell Activation ◽  
Dose Response ◽  
Cell Activation ◽  
Three Dimensional ◽  
Dimensional System ◽  
Two Dimensional ◽  
Converse Implication ◽  
Feedforward Loop ◽  
Three Dimensional System

AbstractIt is well known that the presence of an incoherent feedforward loop (IFFL) in a network may give rise to a steady state non-monotonic dose response. This note shows that the converse implication does not hold. It gives an example of a three-dimensional system that has no IFFLs, yet its dose response is bell-shaped. It also studies under what conditions the result is true for two-dimensional systems, in the process recovering, in far more generality, a result given in the T-cell activation literature.

scholarly journals Discrete-to-continuum modelling of weakly interacting incommensurate two-dimensional lattices

2018 ◽  
Vol 474 (2209) ◽  
pp. 20170612 ◽  
Author(s):  
Malena I. Español ◽  
Dmitry Golovaty ◽  
J. Patrick Wilber
Keyword(s):  
Continuum Model ◽  
Domain Walls ◽  
Three Dimensional ◽  
Variational Model ◽  
Dimensional System ◽  
Two Dimensional ◽  
Starting Point ◽  
Continuum Modelling ◽  
Three Dimensional System ◽  
The Continuum

In this paper, we derive a continuum variational model for a two-dimensional deformable lattice of atoms interacting with a two-dimensional rigid lattice. The starting point is a discrete atomistic model for the two lattices which are assumed to have slightly different lattice parameters and, possibly, a small relative rotation. This is a prototypical example of a three-dimensional system consisting of a graphene sheet suspended over a substrate. We use a discrete-to-continuum procedure to obtain the continuum model which recovers both qualitatively and quantitatively the behaviour observed in the corresponding discrete model. The continuum model predicts that the deformable lattice develops a network of domain walls characterized by large shearing, stretching and bending deformation that accommodates the misalignment and/or mismatch between the deformable and rigid lattices. Two integer-valued parameters, which can be identified with the components of a Burgers vector, describe the mismatch between the lattices and determine the geometry and the details of the deformation associated with the domain walls.

Some Problems of Polar Missile Control

1960 ◽  
Vol 64 (596) ◽  
pp. 482-488 ◽  
Author(s):  
D. Best
Keyword(s):  
Control Systems ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Dimensional System ◽  
Two Dimensional ◽  
Special Design ◽  
Design Problems ◽  
Yaw Control ◽  
Homing Missiles ◽  
Three Dimensional System

A polar-controlled missile is one in which manoeuvre is carried out by rotations about roll and pitch axes, that is, in the manner of a conventional aeroplane. This paper discusses some problems in the application of this form of control to homing missiles.In comparison with the alternative Cartesian configuration, this method presents some special design problems. In the former case, it is often possible to resolve the motion into two planes and consider the pitch and yaw control systems as independent two-dimensional problems. This simplification is not possible in the case of polar control and it is usually necessary to consider the whole three-dimensional system. The equations of motion which result are, in general, not susceptible to analysis. Because of this, the design of control systems requires extensive use of simulators.

scholarly journals TWO-DIMENSIONAL BOSE GAS AT LOW DENSITY

1993 ◽  
Vol 07 (15) ◽  
pp. 1029-1038 ◽  
Author(s):  
A.A. OVCHINNIKOV
Keyword(s):  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Scattering Length ◽  
Three Dimensional ◽  
Bose Gas ◽  
Dimensional System ◽  
Two Dimensional ◽  
Zero Temperature ◽  
Three Dimensional System

We propose a new method to describe the interacting bose gas at zero temperature. For three-dimensional system, the correction to the ground state energy in density is reproduced. For the two-dimensional dilute bose gas, the ground state energy in the leading order in the parameter | ln α2ρ|−1, where α is a two-dimensional scattering length, is obtained.

Inner-product theory calculations for some rational potentials in a three-dimensional system

1996 ◽  
Vol 74 (1-2) ◽  
pp. 4-9
Author(s):  
M. R. M. Witwit
Keyword(s):  
Energy Levels ◽  
Three Dimensional ◽  
Inner Product ◽  
Dimensional System ◽  
Product Technique ◽  
Special Cases ◽  
Wide Range ◽  
Perturbation Parameters ◽  
Three Dimensional System ◽  
Range Of Values

The energy levels of a three-dimensional system are calculated for the rational potentials,[Formula: see text]using the inner-product technique over a wide range of values of the perturbation parameters (λ, g) and for various eigenstates. The numerical results for some special cases agree with those of previous workers where available.

The influence of mean shear on Alfvén-internal wave propagation

1976 ◽  
Vol 15 (2) ◽  
pp. 197-222
Author(s):  
R. J. Hartman
Keyword(s):  
Three Dimensional ◽  
Dimensional System ◽  
Linear Wave ◽  
Mean Flow ◽  
Wave Processes ◽  
Initial Value ◽  
Initial Wave ◽  
Wave Phenomena ◽  
Three Dimensional System

This paper uses the general solution of the linearized initial-value problem for an unbounded, exponentially-stratified, perfectly-conducting Couette flow in the presence of a uniform magnetic field to study the development of localized wave-type perturbations to the basic flow. The two-dimensional problem is shown to be stable for all hydrodynamic Richardson numbers JH, positive and negative, and wave packets in this flow are shown to approach, asymptotically, a level in the fluid (the ‘isolation level’) which is a smooth, continuous, function of JH that is well defined for JH < 0 as well as JH > 0. This system exhibits a rich complement of wave phenomena and a variety of mechanisms for the transport of mean flow kinetic and potential energy, via linear wave processes, between widely-separated regions of fluid; this in addition to the usual mechanisms for the absorption of the initial wave energy itself. The appropriate three-dimensional system is discussed, and the role of nonlinearities on the development of localized disturbances is considered.

Sign in / Sign up

Export Citation Format

Share Document