14,793 research outputs found
Open Transactions on Shared Memory
Transactional memory has arisen as a good way for solving many of the issues
of lock-based programming. However, most implementations admit isolated
transactions only, which are not adequate when we have to coordinate
communicating processes. To this end, in this paper we present OCTM, an
Haskell-like language with open transactions over shared transactional memory:
processes can join transactions at runtime just by accessing to shared
variables. Thus a transaction can co-operate with the environment through
shared variables, but if it is rolled-back, also all its effects on the
environment are retracted. For proving the expressive power of TCCS we give an
implementation of TCCS, a CCS-like calculus with open transactions
Deuteron Magnetic Quadrupole Moment From Chiral Effective Field Theory
We calculate the magnetic quadrupole moment (MQM) of the deuteron at leading
order in the systematic expansion provided by chiral effective field theory. We
take into account parity and time-reversal violation which, at the quark-gluon
level, results from the QCD vacuum angle and dimension-six operators that
originate from physics beyond the Standard Model. We show that the deuteron MQM
can be expressed in terms of five low-energy constants that appear in the
parity- and time-reversal-violating nuclear potential and electromagnetic
current, four of which also contribute to the electric dipole moments of light
nuclei. We conclude that the deuteron MQM has an enhanced sensitivity to the
QCD vacuum angle and that its measurement would be complementary to the
proposed measurements of light-nuclear EDMs
Followers’ HEXACO personality traits and preference for charismatic, relationship-oriented, and task-oriented leadership
The aim of the current study was to examine the HEXACO personality traits in relation to followers’ preference for charismatic,
relationship-oriented, and task-oriented leadership. Based on the similarity perspective, we expected followers high on HonestyHumility, Extraversion, and Openness to Experience to prefer a charismatic leader, and those followers high on conscientiousness
and low on Openness to Experience to prefer a task-oriented leader. In addition, from a need fulfillment perspective, we expected
followers high on Emotionality to prefer a task- and a relationship-oriented leader. We examined these expectations using paper
vignette methodology in a sample of 272 undergraduates. The results showed that most participants preferred a relationshiporiented leader over a charismatic or task-oriented leader. In addition, we found support for all our hypotheses, with the exception
of the relations between Honesty-Humility and preference for charismatic leadership, and Conscientiousness and preference for
task-oriented leadership. Our findings contribute to the nomological network of the role of follower characteristics in the leaderfollower relationship. Implications and suggestions for research on charismatic leadership are provided
DNA-condensation, redissolution and mesocrystals induced by tetravalent counterions
The distance-resolved effective interaction potential between two parallel
DNA molecules is calculated by computer simulations with explicit tetravalent
counterions and monovalent salt. Adding counterions first yields an attractive
minimum in the potential at short distances which then disappears in favor of a
shallower minimum at larger separations. The resulting phase diagram includes a
DNA-condensation and redissolution transition and a stable mesocrystal with an
intermediate lattice constant for high counterion concentration.Comment: 4 pages, 4 figure
Scaling of polymers in aligned rods
We study the behavior of self avoiding polymers in a background of vertically
aligned rods that are either frozen into random positions or free to move
horizontally. We find that in both cases the polymer chains are highly
elongated, with vertical and horizontal size exponents that differ by a factor
of 3. Though these results are different than previous predictions, our results
are confirmed by detailed computer simulations.Comment: 4 pages, 4 figure
Inclusion of non-spherical components of the Pauli blocking operator in (p,p') reactions
We present the first calculations of proton elastic and inelastic scattering
in which the Pauli blocking operator contains the leading non-spherical
components as well as the usual spherical (angle-averaged) part. We develop a
formalism for including the contributions to the effective nucleon-nucleon
interaction from the resulting new G-matrix elements that extend the usual
two-nucleon spin structure and may not conserve angular momentum. We explore
the consequences of parity conservation, time reversal invariance, and
nucleon-nucleon antisymmetrization for the new effective interaction. Changes
to the calculated cross section and spin observables are small in the energy
range from 100 to 200 MeV.Comment: 24 pages, 4 figures, to be published in Physical Review
Parity- and Time-Reversal-Violating Form Factors of the Deuteron
We calculate the electric-dipole and magnetic-quadrupole form factors of the
deuteron that arise as a low-energy manifestation of parity and time-reversal
violation in quark-gluon interactions of effective dimension four and six: the
QCD vacuum angle, the quark electric and chromo-electric dipole moments, and
the gluon chromo-electric dipole moment. Within the framework of two-flavor
chiral perturbation theory, we show that the relative sizes of the
corresponding moments allow an identification of the symmetry-breaking source
Conversion of the prodrug etoposide phosphate to etoposide in gastric juice and bile.
Etoposide phosphate is a water-soluble prodrug of etoposide. It was expected that this prodrug could be used to overcome the solubility limitations and erratic bioavailability of oral etoposide. To investigate the possibility of prodrug conversion to etoposide within the gastrointestinal lumen, etoposide phosphate was dissolved in water and incubated with human gastric juice or human bile in vitro. Samples were collected during 150 min and analysed for etoposide concentration with high-performance liquid chromatography. Conversion of prodrug to etoposide during incubation with gastric juice was negligible. There was significant conversion during incubation with bile at pH 7-8. The percentage of prodrug converted to etoposide at pH 8 after 60 min was 78 +/- 18% (mean +/- S.D.) for a 0.1 mg ml-1 prodrug solution and 36 +/- 26% for 0.5 mg ml-1. At pH 7, after 60 min 22% of prodrug was converted to etoposide when incubated at 0.1 mg ml-1 and 10% at 0.5 mg ml-1. No conversion was found after inactivation of alkaline phosphate (AP) by overnight heating of bile at 65 degrees C or by the addition of disodium edetate to the bile. In conclusion, because of AP in bile, variable conversion of etoposide phosphate to etoposide can be expected within the intestinal lumen after oral administration. This could have important pharmacokinetic consequences
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