12,385 research outputs found
Effects of four Fusarium toxins (fumonisin B(1), alpha-zearalenol, nivalenol and deoxynivalenol) on porcine whole-blood cellular proliferation.
The in vitro effects of four Fusarium toxins, fumonisin B1 (FB1), a-zearalenol (a-ZEA), nivalenol
(NIV) and deoxynivalenol (DON), on mitogen-induced cell proliferation were determined
in swine whole-blood cultures. Considering the lack of sufficient toxicological
data both on single and in combination effects, in vitro studies may contribute to risk assessment
of these toxins. Incubation with increasing concentrations of FB1 did not produce
any consequence on proliferation; in contrast a-ZEA, NIV and DON showed an inhibitory
effect. Dose–response curves for each mycotoxin were generated. NIV was found to be
the most potent toxin followed by DON and a-ZEA. The effects of both FB1 Ăľ a-ZEA and
NIVĂľ DON mixtures were also analysed to investigate possible interactions. The results indicated
that combination of FB1Ăľ a-ZEA produces a synergistic inhibition of porcine cell
proliferation; whereas there is no interaction between DON and NIV on porcine wholeblood
proliferation, at tested concentrations
A multilingual grammar for 'The International Style', and its hybrid grammar
This paper describes the proposal and results of a multilingual shape grammar to describe the designs of three architects, precursors of the 'International Style'. A shape grammar is a generative process that allows the recreation of designs that follow a language. Grammars are useful mechanisms to describe patterns and generative processes that can be used for analysis or design exploration. Most grammars represent one language. This study focuses on three independent languages ​​within the same movement. The proposed grammar is parametric and allows the independent recreation of each independent design. Its difficult application can be linked to the difficult evaluation process. This research proposes a quantitative and a qualitative method of grammar evaluation, using respectively Principal Components Analysis (PCA) and user questionnaires. The results are then discussed and assessed using hybrids that fall in between languages ​​and help delineate parametric spaces
Ionization Mechanisms in Jet-Dominated Seyferts: A Detailed Case Study
For the past 10 years there has been an active debate over whether fast
shocks play an important role in ionizing emission line regions in Seyfert
galaxies. To investigate this claim, we have studied the Seyfert 2 galaxy Mkn
78, using HST UV/optical images and spectroscopy. Since Mkn 78 provides the
archetypal jet-driven bipolar velocity field, if shocks are important anywhere
they should be important in this object. Having mapped the emission line fluxes
and velocity field, we first compare the ionization conditions to standard
photoionization and shock models. We find coherent variations of ionization
consistent with photoionization model sequences which combine optically thick
and thin gas, but are inconsistent with either autoionizing shock models or
photoionization models of just optically thick gas. Furthermore, we find
absolutely no link between the ionization of the gas and its kinematic state,
while we do find a simple decline of ionization degree with radius. We feel
this object provides the strongest case to date against the importance of shock
related ionization in Seyferts.Comment: 4 pages, 1 figure, to appear in the proceedings of IAU Symposium 222
"The Interplay among Black Holes, Stars and ISM in Galactic Nuclei", T.
Storchi Bergmann, L.C. Ho & H.R. Schmitt, ed
The Nuclear Outflow in NGC 2110
We present a HST/STIS spectroscopic and optical/radio imaging study of the
Seyfert NGC 2110 aiming to measure the dynamics and understand the nature of
the nuclear outflow in the galaxy. Previous HST studies have revealed the
presence of a linear structure in the Narrow-Line Region (NLR) aligned with the
radio jet. We show that this structure is strongly accelerated, probably by the
jet, but is unlikely to be entrained in the jet flow. The ionisation properties
of this structure are consistent with photoionisation of dusty, dense gas by
the active nucleus. We present a plausible geometrical model for the NLR,
bringing together various components of the nuclear environment of the galaxy.
We highlight the importance of the circum-nuclear disc in determining the
appearance of the emission line gas and the morphology of the jet. From the
dynamics of the emission line gas, we place constraints on the accelerating
mechanism of the outflow and discuss the relative importance of radio source
synchrotron pressure, radio jet ram pressure and nuclear radiation pressure in
accelerating the gas. While all three mechanisms can account for the energetics
of the emission line gas, gravitational arguments support radio jet ram
pressure as the most likely source of the outflow.Comment: 15 pages, 7 figures; accepted to MNRA
Community Partnerships for Cultural Participation: Concepts, Prospects, and Challenges
Evaluates the first year of the Wallace Foundation's Community Partnerships for Cultural Participation Initiative, which funded nine community foundations working to increase participation in the arts and culture in their communities
Theory of integer quantum Hall polaritons in graphene
We present a theory of the cavity quantum electrodynamics of the graphene
cyclotron resonance. By employing a canonical transformation, we derive an
effective Hamiltonian for the system comprised of two neighboring Landau levels
dressed by the cavity electromagnetic field (integer quantum Hall polaritons).
This generalized Dicke Hamiltonian, which contains terms that are quadratic in
the electromagnetic field and respects gauge invariance, is then used to
calculate thermodynamic properties of the quantum Hall polariton system.
Finally, we demonstrate that the generalized Dicke description fails when the
graphene sheet is heavily doped, i.e. when the Landau level spectrum of 2D
massless Dirac fermions is approximately harmonic. In this case we `integrate
out' the Landau levels in valence band and obtain an effective Hamiltonian for
the entire stack of Landau levels in conduction band, as dressed by strong
light-matter interactions.Comment: 20 pages, 7 figure
Robust optimal quantum gates for Josephson charge qubits
Quantum optimal control theory allows to design accurate quantum gates. We
employ it to design high-fidelity two-bit gates for Josephson charge qubits in
the presence of both leakage and noise. Our protocol considerably increases the
fidelity of the gate and, more important, it is quite robust in the disruptive
presence of 1/f noise. The improvement in the gate performances discussed in
this work (errors of the order of 10^{-3}-10^{-4} in realistic cases) allows to
cross the fault tolerance threshold.Comment: 4 pages, 4 figure
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