217 research outputs found
The chromatographic identification of some biologically important phosphate esters
the objective of the present work was to provide a means for separating and indentifying phosphate esters involved in glycolysis in higher plants. Paper chromatography of phosphate esters has been employed by several workers, most notably Benson et al. (1) and Hanes and Isherwood (2). Benson's procedures were not primarily designed for identification of phosphate esters and gave low Rr values for the phosphate compounds of particular interest to us. The unidimensional methods of Hanes and Isherwood do not result in adequate resolution of the complex mixtures such as are obtained from our plant materials.
The present procedure is based on two-dimensional chromatography with successive development in an acid and in a basic solvent. The solvents finally selected gave the best over-all resolution of the intermediates involved in plant glycolysis. Undoubtedly the resolution of certain pairs of compounds may be improved by suitable modifications. We have in addition made certain improvements in the procedure for locating the chromatographed materials
Elliptic Wess-Zumino-Witten Model from Elliptic Chern-Simons Theory
This letter continues the program aimed at analysis of the scalar product of
states in the Chern-Simons theory. It treats the elliptic case with group
SU(2). The formal scalar product is expressed as a multiple finite dimensional
integral which, if convergent for every state, provides the space of states
with a Hilbert space structure. The convergence is checked for states with a
single Wilson line where the integral expressions encode the Bethe-Ansatz
solutions of the Lame equation. In relation to the Wess-Zumino-Witten conformal
field theory, the scalar product renders unitary the
Knizhnik-Zamolodchikov-Bernard connection and gives a pairing between conformal
blocks used to obtain the genus one correlation functions.Comment: 18 pages, late
On the deconfining limit in (2+1)-dimensional Yang-Mills theory
We consider (2+1)-dimensional Yang-Mills theory on in the framework of a Hamiltonian approach developed by Karabali, Kim
and Nair. The deconfining limit in the theory can be discussed in terms of one
of the radii of the torus (), while the other radius goes
to infinity. We find that the limit agrees with the previously known result for
a dynamical propagator mass of a gluon. We also make comparisons with numerical
data.Comment: 21 pages; v2. lattice data references updated, comparative statements
revised; v3. minor corrections; v4. section 6 extended, published versio
Combinatorial quantization of the Hamiltonian Chern-Simons theory I
Motivated by a recent paper of Fock and Rosly \cite{FoRo} we describe a
mathematically precise quantization of the Hamiltonian Chern-Simons theory. We
introduce the Chern-Simons theory on the lattice which is expected to reproduce
the results of the continuous theory exactly. The lattice model enjoys the
symmetry with respect to a quantum gauge group. Using this fact we construct
the algebra of observables of the Hamiltonian Chern-Simons theory equipped with
a *-operation and a positive inner product.Comment: 49 pages. Some minor corrections, discussion of positivity improved,
a number of remarks and a reference added
Chern-Simons States at Genus One
We present a rigorous analysis of the Schr\"{o}dinger picture quantization
for the Chern-Simons theory on 3-manifold torusline, with
insertions of Wilson lines. The quantum states, defined as gauge covariant
holomorphic functionals of smooth -connections on the torus, are
expressed by degree theta-functions satisfying additional conditions. The
conditions are obtained by splitting the space of semistable
-connections into nine submanifolds and by analyzing the behavior of
states at four codimension strata. We construct the
Knizhnik-Zamolodchikov-Bernard connection allowing to compare the states for
different complex structures of the torus and different positions of the Wilson
lines. By letting two Wilson lines come together, we prove a recursion relation
for the dimensions of the spaces of states which, together with the (unproven)
absence of states for spins\s>{_1\over^2}level implies the Verlinde dimension
formula.Comment: 33 pages, IHES/P
Chern-Simons theory and BCS superconductivity
We study the relationship between the holomorphic unitary connection of
Chern-Simons theory with temporal Wilson lines and the Richardson's exact
solution of the reduced BCS Hamiltonian. We derive the integrals of motion of
the BCS model, their eigenvalues and eigenvectors as a limiting case of the
Chern-Simons theory.Comment: 23 page
SU(2) WZW Theory at Higher Genera
We compute, by free field techniques, the scalar product of the SU(2)
Chern-Simons states on genus > 1 surfaces. The result is a finite-dimensional
integral over positions of ``screening charges'' and one complex modular
parameter. It uses an effective description of the CS states closely related to
the one worked out by Bertram. The scalar product formula allows to express the
higher genus partition functions of the WZW conformal field theory by
finite-dimensional integrals. It should provide the hermitian metric preserved
by the Knizhnik-Zamolodchikov-Bernard connection describing the variations of
the CS states under the change of the complex structure of the surface.Comment: 44 pages, IHES/P/94/10, Latex fil
Embodied Evolution in Collective Robotics: A Review
This paper provides an overview of evolutionary robotics techniques applied
to on-line distributed evolution for robot collectives -- namely, embodied
evolution. It provides a definition of embodied evolution as well as a thorough
description of the underlying concepts and mechanisms. The paper also presents
a comprehensive summary of research published in the field since its inception
(1999-2017), providing various perspectives to identify the major trends. In
particular, we identify a shift from considering embodied evolution as a
parallel search method within small robot collectives (fewer than 10 robots) to
embodied evolution as an on-line distributed learning method for designing
collective behaviours in swarm-like collectives. The paper concludes with a
discussion of applications and open questions, providing a milestone for past
and an inspiration for future research.Comment: 23 pages, 1 figure, 1 tabl
A Conflict Model for Strategists and Managers
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67210/2/10.1177_000276427201500604.pd
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