1,357,874 research outputs found
Strange loves: a remarkable case of aberrant copulation in beetles (Coleoptera: Meloidae, Chrysomelidae)
A case of copulation between two mimic and repellent beetle species (a male of Timarcha fracassii, and a female of Meloe autumnalis), belonging to distinct families (Chrysomelidae, Meloidae), is recorded
A remarkable periodic solution of the three-body problem in the case of equal masses
Using a variational method, we exhibit a surprisingly simple periodic orbit
for the newtonian problem of three equal masses in the plane. The orbit has
zero angular momentum and a very rich symmetry pattern. Its most surprising
feature is that the three bodies chase each other around a fixed eight-shaped
curve. Setting aside collinear motions, the only other known motion along a
fixed curve in the inertial plane is the ``Lagrange relative equilibrium" in
which the three bodies form a rigid equilateral triangle which rotates at
constant angular velocity within its circumscribing circle. Our orbit visits in
turns every ``Euler configuration" in which one of the bodies sits at the
midpoint of the segment defined by the other two (Figure 1). Numerical
computations by Carles Sim\'o, to be published elsewhere, indicate that the
orbit is ``stable" (i.e. completely elliptic with torsion). Moreover, they show
that the moment of inertia I(t) with respect to the center of mass and the
potential U(t) as functions of time are almost constant.Comment: 21 pages, published versio
Robert Nye’s Falstaff: A Remarkable Case of Creative Reception
Among fictitious autobiographies as well as among historical novels, Robert Nye’s Falstaff (1976) is a special case in that it is not the autobiography of a historical personage, but of a dramatic character —who happens to be one of the most famous in Shakespeare, indeed in world drama, to be dictated by Falstaff to various amanuenses. After briefly discussing the sub-genre of fictitious autobiography, this paper will analyze the varied use of intertextuality, the tensions fabricated between the autobiographer and his helpers, and the critical thoughts and tendencies which Nye absorbed in preparing the work with particular emphasis on the clash between the Shakespearean intertexts and the diction surrounding it
Extremal polynomials in stratified groups
We introduce a family of extremal polynomials associated with the prolongation of a stratified nilpotent Lie algebra. These polynomials tre related to a new algebraic characterization of abnormal sub-Riemannian extremals in stratified nilpotent Lie groups. They satisfy a set of remarkable structure relations that are used to integrate the adjoint equations, in both normal and abnormal case
Using PT-symmetry for switching applications
This work introduces a new class of PT-symmetry grating assisted devices for
switching or modulation applications. Their operation is based on a four-wave
interaction, thus marking a step in the further development of PT-symmetry
devices which currently are essentially based on two-wave interactions. A
remarkable feature of the new device is that all their properties also hold for
the case of imperfect PT-symmetry operation, corresponding to the important
practical case of fixed losses
A model of protocell based on the introduction of a semi-permeable membrane in a stochastic model of catalytic reaction networks
In this work we introduce some preliminary analyses on the role of a
semi-permeable membrane in the dynamics of a stochastic model of catalytic
reaction sets (CRSs) of molecules. The results of the simulations performed on
ensembles of randomly generated reaction schemes highlight remarkable
differences between this very simple protocell description model and the
classical case of the continuous stirred-tank reactor (CSTR). In particular, in
the CSTR case, distinct simulations with the same reaction scheme reach the
same dynamical equilibrium, whereas, in the protocell case, simulations with
identical reaction schemes can reach very different dynamical states, despite
starting from the same initial conditions.Comment: In Proceedings Wivace 2013, arXiv:1309.712
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