3,599 research outputs found
Static displacements and chemical correlations in alloys
Recent experiments in metallic solid solutions have revealed interesting
correlations between static pair-displacements and the ordering behavior of
these alloys. This paper discusses a simple theoretical model which
successfully explains these observations and which provides a natural framework
for analyzing experimental measurements of pair-displacements and chemical
correlations in solid solutions. The utility and scope of this model is
demonstrated by analyzing results of experiments on and alloys
and results of simulations of and alloys.Comment: 12 page
Algebraic K-theory of endomorphism rings
We establish formulas for computation of the higher algebraic -groups of
the endomorphism rings of objects linked by a morphism in an additive category.
Let be an additive category, and let Y\ra X be a covariant
morphism of objects in . Then for all , where is the
quotient ring of the endomorphism ring of modulo the
ideal generated by all those endomorphisms of which factorize through .
Moreover, let be a ring with identity, and let be an idempotent element
in . If is homological and has a finite projective resolution
by finitely generated projective -modules, then for all . This reduces calculations of the higher
algebraic -groups of to those of the quotient ring and the corner
ring , and can be applied to a large variety of rings: Standardly
stratified rings, hereditary orders, affine cellular algebras and extended
affine Hecke algebras of type .Comment: 21 pages. Representation-theoretic methods are used to study the
algebraic K-theory of ring
Free field realization of the exceptional current superalgebra \hat{D(2,1;\a)}_k
The free-field representations of the D(2,1;\a) current superalgebra and
the corresponding energy-momentum tensor are constructed. The related screening
currents of the first kind are also presented.Comment: Latex file, 10 page
High-dimensional super-resolution imaging reveals heterogeneity and dynamics of subcellular lipid membranes.
Lipid membranes are found in most intracellular organelles, and their heterogeneities play an essential role in regulating the organelles' biochemical functionalities. Here we report a Spectrum and Polarization Optical Tomography (SPOT) technique to study the subcellular lipidomics in live cells. Simply using one dye that universally stains the lipid membranes, SPOT can simultaneously resolve the membrane morphology, polarity, and phase from the three optical-dimensions of intensity, spectrum, and polarization, respectively. These high-throughput optical properties reveal lipid heterogeneities of ten subcellular compartments, at different developmental stages, and even within the same organelle. Furthermore, we obtain real-time monitoring of the multi-organelle interactive activities of cell division and successfully reveal their sophisticated lipid dynamics during the plasma membrane separation, tunneling nanotubules formation, and mitochondrial cristae dissociation. This work suggests research frontiers in correlating single-cell super-resolution lipidomics with multiplexed imaging of organelle interactome
Dynamics of Ordering in Alloys with Modulated Phases
This paper presents a theoretical model for studying the dynamics of ordering
in alloys which exhibit modulated phases. The model is different from the
standard time-dependent Ginzburg-Landau description of the evolution of a
non-conserved order parameter and resembles the Swift-Hohenberg model. The
early-stage growth kinetics is analyzed and compared to the Cahn-Hilliard
theory of continuous ordering. The effects of non-linearities on the growth
kinetics are discussed qualitatively and it is shown that the presence of an
underlying elastic lattice introduces qualitatively new effects. A lattice
Hamiltonian capable of describing these effects and suitable for carrying out
simulations of the growth kinetics is also constructed.Comment: 18 pages, 3 figures (postscript files appended), Brandeis-BC9
Ethosuximide ameliorates neurodegenerative disease phenotypes by modulating DAF-16/FOXO target gene expression
Background Many neurodegenerative diseases are associated with protein misfolding/aggregation. Treatments mitigating the effects of such common pathological processes, rather than disease-specific symptoms, therefore have general therapeutic potential. Results Here we report that the anti-epileptic drug ethosuximide rescues the short lifespan and chemosensory defects exhibited by C. elegans null mutants of dnj-14, the worm orthologue of the DNAJC5 gene mutated in autosomal-dominant adult-onset neuronal ceroid lipofuscinosis. It also ameliorates the locomotion impairment and short lifespan of worms expressing a human Tau mutant that causes frontotemporal dementia. Transcriptomic analysis revealed a highly significant up-regulation of DAF-16/FOXO target genes in response to ethosuximide; and indeed RNAi knockdown of daf-16 abolished the therapeutic effect of ethosuximide in the worm dnj-14 model. Importantly, ethosuximide also increased the expression of classical FOXO target genes and reduced protein aggregation in mammalian neuronal cells. Conclusions We have revealed a conserved neuroprotective mechanism of action of ethosuximide from worms to mammalian neurons. Future experiments in mouse neurodegeneration models will be important to confirm the repurposing potential of this well-established anti-epileptic drug for treatment of human neurodegenerative diseases
Assessment of Dentally Related Function in Individuals with Cognitive Impairment: The Dental Activities Test
To develop and validate the Dental Activities Test (DAT), a clinical tool for measuring dentally-related function in cognitively-impaired older adults
Determinant representations of scalar products for the open XXZ chain with non-diagonal boundary terms
With the help of the F-basis provided by the Drinfeld twist or factorizing
F-matrix for the open XXZ spin chain with non-diagonal boundary terms, we
obtain the determinant representations of the scalar products of Bethe states
of the model.Comment: Latex file, 28 pages, based on the talk given by W. -L. Yang at
Statphys 24, Cairns, Australia, 19-23 July, 201
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