4,667 research outputs found
Scott Ranks of Classifications of the Admissibility Equivalence Relation
Let be a recursive language. Let be the set of
-structures with domain . Let be a function with the property that
for all , if and only if
. Then there is some
so that
Organic Cation Transporter 3 (OCT3) Is Localized to Intracellular and Surface Membranes in Select Glial and Neuronal Cells Within the Basolateral Amygdaloid Complex of Both Rats and Mice
Organic cation transporter 3 (OCT3) is a high-capacity, low-affinity transporter that mediates corticosterone-sensitive uptake of monoamines including norepinephrine, epinephrine, dopamine, histamine and serotonin. OCT3 is expressed widely throughout the amygdaloid complex and other brain regions where monoamines are key regulators of emotional behaviors affected by stress. However, assessing the contribution of OCT3 to the regulation of monoaminergic neurotransmission and monoamine-dependent regulation of behavior requires fundamental information about the subcellular distribution of OCT3 expression. We used immunofluorescence and immuno-electron microscopy to examine the cellular and subcellular distribution of the transporter in the basolateral amygdaloid complex of the rat and mouse brain. OCT3-immunoreactivity was observed in both glial and neuronal perikarya in both rat and mouse amygdala. Electron microscopic immunolabeling revealed plasma membrane-associated OCT3 immunoreactivity on axonal, dendritic, and astrocytic processes adjacent to a variety of synapses, as well as on neuronal somata. In addition to plasma membrane sites, OCT3 immunolabeling was also observed associated with neuronal and glial endomembranes, including Golgi, mitochondrial and nuclear membranes. Particularly prominent labeling of the outer nuclear membrane was observed in neuronal, astrocytic, microglial and endothelial perikarya. The localization of OCT3 to neuronal and glial plasma membranes adjacent to synaptic sites is consistent with an important role for this transporter in regulating the amplitude, duration, and physical spread of released monoamines, while its localization to mitochondrial and outer nuclear membranes suggests previously undescribed roles for the transporter in the intracellular disposition of monoamines
Entropic Priors and Bayesian Model Selection
We demonstrate that the principle of maximum relative entropy (ME), used
judiciously, can ease the specification of priors in model selection problems.
The resulting effect is that models that make sharp predictions are
disfavoured, weakening the usual Bayesian "Occam's Razor". This is illustrated
with a simple example involving what Jaynes called a "sure thing" hypothesis.
Jaynes' resolution of the situation involved introducing a large number of
alternative "sure thing" hypotheses that were possible before we observed the
data. However, in more complex situations, it may not be possible to explicitly
enumerate large numbers of alternatives. The entropic priors formalism produces
the desired result without modifying the hypothesis space or requiring explicit
enumeration of alternatives; all that is required is a good model for the prior
predictive distribution for the data. This idea is illustrated with a simple
rigged-lottery example, and we outline how this idea may help to resolve a
recent debate amongst cosmologists: is dark energy a cosmological constant, or
has it evolved with time in some way? And how shall we decide, when the data
are in?Comment: Presented at MaxEnt 2009, the 29th International Workshop on Bayesian
Inference and Maximum Entropy Methods in Science and Engineering (July 5-10,
2009, Oxford, Mississippi, USA
Sandpiles, spanning trees, and plane duality
Let G be a connected, loopless multigraph. The sandpile group of G is a
finite abelian group associated to G whose order is equal to the number of
spanning trees in G. Holroyd et al. used a dynamical process on graphs called
rotor-routing to define a simply transitive action of the sandpile group of G
on its set of spanning trees. Their definition depends on two pieces of
auxiliary data: a choice of a ribbon graph structure on G, and a choice of a
root vertex. Chan, Church, and Grochow showed that if G is a planar ribbon
graph, it has a canonical rotor-routing action associated to it, i.e., the
rotor-routing action is actually independent of the choice of root vertex.
It is well-known that the spanning trees of a planar graph G are in canonical
bijection with those of its planar dual G*, and furthermore that the sandpile
groups of G and G* are isomorphic. Thus, one can ask: are the two rotor-routing
actions, of the sandpile group of G on its spanning trees, and of the sandpile
group of G* on its spanning trees, compatible under plane duality? In this
paper, we give an affirmative answer to this question, which had been
conjectured by Baker.Comment: 13 pages, 9 figure
A Study of the Tradition of Extreme Literature
This thesis endeavours to investigate some of the many ways literary works can engage with the tradition of extremism. In so doing, the author hopes to demonstrate the importance of the tradition as a vessel for understanding the world around and within us. In an effort to show the breadth and endurance of this tradition, this thesis critically analyses selected works by Robert Browning, Harold Pinter, and Frank Bidart in context with various other literary works
Exploring the magnetic properties of the largest single molecule magnets
The giant {Mn₇₀} and {Mn₈₄} wheels are the largest nuclearity single-molecule magnets synthesized to date, and understanding their magnetic properties poses a challenge to theory. Starting from first-principles calculations, we explore the magnetic properties and excitations in these wheels using effective spin Hamiltonians. We find that the unusual geometry of the superexchange pathways leads to weakly coupled {Mn₇} subunits carrying an effective S = 2 spin. The spectrum exhibits a hierarchy of energy scales and massive degeneracies, with the lowest-energy excitations arising from Heisenberg-ring-like excitations of the {Mn₇} subunits around the wheel. We further describe how weak longer-range couplings can select the precise spin ground-state of the Mn wheels out of the nearly degenerate ground-state band
Low Pressure Ethenolysis of Renewable Methyl Oleate in a Microchemical System
A microchemical system for ethenolysis of renewable methyl oleate was developed, in which the dual-phase, microfluidic design enabled efficient diffusion of ethylene gas into liquid methyl oleate through an increased contact area. The increased mass transfer of ethylene favored the formation of desired commodity chemicals with significantly suppressed homometathesis when compared to the bulk system. In addition to higher selectivity and conversion, this system also provides the typical advantages of a microchemical system, including the possibility of convenient scale-up
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