9,476 research outputs found
Derivatives at Agricultural Banks
Using data between 1995 and 2010, we find that agricultural banks are benefiting from the derivatives activities by reducing total risk without hurting their profit. In nonagricultural banks, both profitability and total risk are adversely affected, possibly due to speculative derivatives positions.Agricultural Banks, Financial Derivatives, Profitability, Risk Management, Agricultural Finance, Risk and Uncertainty,
Weighted bounds for multilinear operators with non-smooth kernels
Let be a multilinear integral operator which is bounded on certain
products of Lebesgue spaces on . We assume that its associated
kernel satisfies some mild regularity condition which is weaker than the usual
H\"older continuity of those in the class of multilinear Calder\'on-Zygmund
singular integral operators. In this paper, given a suitable multiple weight
, we obtain the bound for the weighted norm of multilinear operators
in terms of . As applications, we exploit this result to obtain
the weighted bounds for certain singular integral operators such as linear and
multilinear Fourier multipliers and the Riesz transforms associated to
Schr\"odinger operators on . Our results are new even in the
linear case
Model Counting for Formulas of Bounded Clique-Width
We show that #SAT is polynomial-time tractable for classes of CNF formulas
whose incidence graphs have bounded symmetric clique-width (or bounded
clique-width, or bounded rank-width). This result strictly generalizes
polynomial-time tractability results for classes of formulas with signed
incidence graphs of bounded clique-width and classes of formulas with incidence
graphs of bounded modular treewidth, which were the most general results of
this kind known so far.Comment: Extended version of a paper published at ISAAC 201
Molecular dynamics of folding of secondary structures in Go-type models of proteins
We consider six different secondary structures of proteins and construct two
types of Go-type off-lattice models: with the steric constraints and without.
The basic aminoacid-aminoacid potential is Lennard Jones for the native
contacts and a soft repulsion for the non-native contacts. The interactions are
chosen to make the target secondary structure be the native state of the
system. We provide a thorough equilibrium and kinetic characterization of the
sequences through the molecular dynamics simulations with the Langevin noise.
Models with the steric constraints are found to be better folders and to be
more stable, especially in the case of the -structures. Phononic spectra
for vibrations around the native states have low frequency gaps that correlate
with the thermodynamic stability. Folding of the secondary structures proceeds
through a well defined sequence of events. For instance, -helices fold
from the ends first. The closer to the native state, the faster establishment
of the contacts. Increasing the system size deteriorates the folding
characteristics. We study the folding times as a function of viscous friction
and find a regime of moderate friction with the linear dependence. We also
consider folding when one end of a structure is pinned which imitates
instantaneous conditions when a protein is being synthesized. We find that,
under such circumstances, folding of helices is faster and of the
-sequences slower.Comment: REVTeX, 14 pages, EPS figures included, JCP in pres
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