1,235 research outputs found
THE EFFECT OF CONDTIONAL DISCRIMINATION TRAINING ON CHOICE MAKING IN CHILDREN DURING `PRE-GAMBLING\u27 ACTIVITIES
Past research has shown conditional discrimination training of a stimulus to change its function by manipulating variables within the contingencies (e.g., Johnson & Dixon, 2009), and the present study attempted to extend this research. Experimenters exposed 3 children (ages 6-9 years) to a computer program that trained participant to discriminate between two contextual cures (blue and yellow) representing more than and less than. All three participants will demonstrate an increased preference toward the color that had been paired with more than during both conditional discrimination training phases
Efficiency of initiating cell adhesion in hydrodynamic flow
We theoretically investigate the efficiency of initial binding between a
receptor-coated sphere and a ligand-coated wall in linear shear flow. The mean
first passage time for binding decreases monotonically with increasing shear
rate. Above a saturation threshold of the order of a few 100 receptor patches,
the binding efficiency is enhanced only weakly by increasing their number and
size, but strongly by increasing their height. This explains why white blood
cells in the blood flow adhere through receptor patches localized to the tips
of microvilli, and why malaria-infected red blood cells form elevated receptor
patches (knobs).Comment: 4 pages, Revtex, 4 Postscript figures included, to appear in PR
On sets of irreducible polynomials closed by composition
Let be a set of monic degree polynomials over a finite field
and let be the compositional semigroup generated by . In this
paper we establish a necessary and sufficient condition for to be
consisting entirely of irreducible polynomials. The condition we deduce depends
on the finite data encoded in a certain graph uniquely determined by the
generating set . Using this machinery we are able both to show
examples of semigroups of irreducible polynomials generated by two degree
polynomials and to give some non-existence results for some of these sets in
infinitely many prime fields satisfying certain arithmetic conditions
Signing on a Postcard
We investigate the problem of signing short messages using a scheme that minimizes the total length of the original message and the appended signature. This line of research was motivated by several postal services interested by stamping machines capable of producing digital signatures. Although several message recovery schemes exist, their security is questionable. This paper proposes variants of DSA and ECDSA allowing partial recovery: the signature is appended to a truncated message and the discarded bytes are recovered by the verification algorithm
Evaluating the Effect of Crutch-using on Trunk Muscle Loads
As a traditional tool of external assistance, crutches play an important role
in society. They have a wide range of applications to help either the elderly
and disabled to walk or to treat certain illnesses or for post-operative
rehabilitation. But there are many different types of crutches, including
shoulder crutches and elbow crutches. How to choose has become an issue that
deserves to be debated. Because while crutches help people walk, they also have
an impact on the body. Inappropriate choice of crutches or long-term misuse can
lead to problems such as scoliosis. Previous studies were mainly experimental
measurements or the construction of dynamic models to calculate the load on
joints with crutches. These studies focus only on the level of the joints,
ignoring the role that muscles play in this process. Although some also take
into account the degree of muscle activation, there is still a lack of
quantitative analysis. The traditional dynamic model can be used to calculate
the load on each joint. However, due to the activation of the muscle, this
situation only causes part of the load transmitted to the joint, and the work
of the chair will compensate the other part of the load. Analysis at the muscle
level allows a better understanding of the impact of crutches on the body. By
comparing the levels of activation of the trunk muscles, it was found that the
use of crutches for walking, especially a single crutch, can cause a large
difference in the activation of the back muscles on the left and right sides,
and this difference will cause muscle degeneration for a long time, leading to
scoliosis. In this article taking scoliosis as an example, by analyzing the
muscles around the spine, we can better understand the pathology and can better
prevent diseases. The objective of this article is to analyze normal walking
compared to walking with one or two crutches using OpenSim software to obtain
the degree of activation of different muscles in order to analyze the impact of
crutches on the body
L-selectin mediated leukocyte tethering in shear flow is controlled by multiple contacts and cytoskeletal anchorage facilitating fast rebinding events
L-selectin mediated tethers result in leukocyte rolling only above a
threshold in shear. Here we present biophysical modeling based on recently
published data from flow chamber experiments (Dwir et al., J. Cell Biol. 163:
649-659, 2003) which supports the interpretation that L-selectin mediated
tethers below the shear threshold correspond to single L-selectin carbohydrate
bonds dissociating on the time scale of milliseconds, whereas L-selectin
mediated tethers above the shear threshold are stabilized by multiple bonds and
fast rebinding of broken bonds, resulting in tether lifetimes on the timescale
of seconds. Our calculations for cluster dissociation suggest that
the single molecule rebinding rate is of the order of Hz. A similar
estimate results if increased tether dissociation for tail-truncated L-selectin
mutants above the shear threshold is modeled as diffusive escape of single
receptors from the rebinding region due to increased mobility. Using computer
simulations, we show that our model yields first order dissociation kinetics
and exponential dependence of tether dissociation rates on shear stress. Our
results suggest that multiple contacts, cytoskeletal anchorage of L-selectin
and local rebinding of ligand play important roles in L-selectin tether
stabilization and progression of tethers into persistent rolling on endothelial
surfaces.Comment: 9 pages, Revtex, 4 Postscript figures include
A faster pseudo-primality test
We propose a pseudo-primality test using cyclic extensions of . For every positive integer , this test achieves the
security of Miller-Rabin tests at the cost of Miller-Rabin
tests.Comment: Published in Rendiconti del Circolo Matematico di Palermo Journal,
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