113,164 research outputs found
Toward an ecological aesthetics: music as emergence
In this article we intend to suggest some ecological based principles
to support the possibility of develop an ecological aesthetics. We consider that
an ecological aesthetics is founded in concepts as âdirect perceptionâ,
âacquisition of affordances and invariantsâ, âembodied embedded
perceptionâ and so on. Here we will purpose that can be possible explain
especially soundscape music perception in terms of direct perception, working
with perception of first hand (in a Gibsonian sense). We will present notions
as embedded sound, detection of sonic affordances and invariants, and at the
end we purpose an experience with perception/action paradigm to make
soundscape music as emergence of a self-organized system
The lattice Landau gauge gluon propagator: lattice spacing and volume dependence
The interplay between the finite volume and finite lattice spacing is
investigated using lattice QCD simulations to compute the Landau gauge gluon
propagator. Comparing several ensembles with different lattice spacings and
physical volumes, we conclude that the dominant effects, in the infrared
region, are associated with the use of a finite lattice spacing. The
simulations show that decreasing the lattice spacing, while keeping the same
physical volume, leads to an enhancement of the infrared gluon propagator. In
this sense, the data from simulations, which uses an fm, provides a lower bound for the infinite volume propagator.Comment: Final version to appear in Phys Rev
2013 REU Poster: Purification and Characterization of a Ferredoxin from Mycobacterium tuberculosis
Poster presentation at REU Summer's End Research Symposium, 2013, by REU participant Jonas A, de Oliveira, MassBay Community College - Sean Elliott group, Evan Judd lab mentorM. tuberculosis possesses a sulfite reductase (MtsirA) that is over-expressed when the
bacteria is in its dormant stage of infection. MtSirA catalyzes the six-electron reduction
of sulfite to sulfide. Previous kinetic studies of MtsirA have used methyl viologen
(MV), a chemical reductant, as an electron donor. The goal of this work is to purify and
characterize a ferredoxin from M. tuberculosis (MtFd) and determine if MtFd can act
as an electron donor to mtSirA, with the ultimate goal of using it as a more
physiologically relevant electron donor in kinetic studies of mtSirA. We have found that
that MtFd purifies without a cluster and must be chemically reconstituted. MtFd likely
contains a [4Fe-4S] cluster, and may be able to donate electrons to mtSirA.NSF-RE
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