1,066 research outputs found
Equilibrium Statistical Mechanics of Fermion Lattice Systems
We study equilibrium statistical mechanics of Fermion lattice systems which
require a different treatment compared with spin lattice systems due to the
non-commutativity of local algebras for disjoint regions.
Our major result is the equivalence of the KMS condition and the variational
principle with a minimal assumption for the dynamics and without any explicit
assumption on the potential. It holds also for spin lattice systems as well,
yielding a vast improvement over known results.
All formulations are in terms of a C*-dynamical systems for the Fermion (CAR)
algebra with all or a part of the following assumptions:
(I) The interaction is even with respect to the Fermion number.
(Automatically satisfied when (IV) below is assumed.)
(II) All strictly local elements of the algebra have the first time
derivative.
(III) The time derivatives in (II) determine the dynamics.
(IV) The interaction is lattice translation invariant.
A major technical tool is the conditional expectation from the total algebra
onto the local subalgebra for any finite subset of the lattice, which induces a
system of commuting squares. This technique overcomes the lack of tensor
product structures for Fermion systems and even simplifies many known arguments
for spin lattice systems.Comment: 103 pages, no figure. The Section 13 has become simpler and a problem
in 14.1 is settled thanks to a referee. The format has been revised according
to the suggestion of this and the other referee
Demonstration of novel gain‐of‐function mutations of αIIbβ3: association with macrothrombocytopenia and glanzmann thrombasthenia‐like phenotype
Different Types of Conditional Expectation and the Lueders - von Neumann Quantum Measurement
In operator algebra theory, a conditional expectation is usually assumed to
be a projection map onto a sub-algebra. In the paper, a further type of
conditional expectation and an extension of the Lueders - von Neumann
measurement to observables with continuous spectra are considered; both are
defined for a single operator and become a projection map only if they exist
for all operators. Criteria for the existence of the different types of
conditional expectation and of the extension of the Lueders - von Neumann
measurement are presented, and the question whether they coincide is studied.
All this is done in the general framework of Jordan operator algebras. The
examples considered include the type I and type II operator algebras, the
standard Hilbert space model of quantum mechanics, and a no-go result
concerning the conditional expectation of observables that satisfy the
canonical commutator relation.Comment: 10 pages, the original publication is available at
http://www.springerlink.co
A Schmidt number for density matrices
We introduce the notion of a Schmidt number of a bipartite density matrix,
characterizing the minimum Schmidt rank of the pure states that are needed to
construct the density matrix. We prove that Schmidt number is nonincreasing
under local quantum operations and classical communication. We show that
-positive maps witness Schmidt number, in the same way that positive maps
witness entanglement. We show that the family of states which is made from
mixing the completely mixed state and a maximally entangled state have
increasing Schmidt number depending on the amount of maximally entangled state
that is mixed in. We show that Schmidt number {\it does not necessarily
increase} when taking tensor copies of a density matrix ; we give an
example of a density matrix for which the Schmidt numbers of and are both 2.Comment: 5 pages RevTex, 1 typo in Proof Lemma 1 correcte
The Effects of Cellulase on Cell Wall Structure and the Rumen Digestion of Alfalfa Silage
First- and second-cut alfalfa (Medicago sativa) was ensiled with no additive, microbial (Lactobacillus casei) inoculant, cellulase derived from Acremonium celluloytics Y-94, co-addition of inoculant and cellulase, and formic acid. The resultant silages were digested in the rumen of a dairy cow. The alfalfa and the silages were then examined with scanning electron microscope (SEM) and their chemical characteristics analyzed to evaluate the effects of cellulase on the quality of alfalfa silage and its cell wall structure.
The addition of cellulase lend to both a greater loss of parenchymal tissue and decrease in digestibility during rumen degradation than did the other additives moreover, photos taken during SEM examination also showed that cellulase affected cell wall decomposition. The results of this study may suggest that the addition of cellulase affects fiber digestion by ruminant animals
The Effect of Cellulase on Cell Wall Structure and the Rumen Digestion of Timothy Silage
The objective of this study was to determine the effect of additives on the structure changes of related tissues during the ensiling process and the rumen digestion of timothy. In the first cut-timothy, the addition of LC+AC improved the fermentation qualities of the silage. Addition of cellulase resulted in significant decreases in NDF, ADF, cellulose, and hemicellulose content. SEM examination of the samples suggests that the degradation of parenchymal tissues was enhanced by the cellulase, but no significant differences were observed among the additives in the rumen digestion. The NDF and cellulose digestibility of the AC- and LC+AC-treated silages were lower than those of the other silages. In the second one, after digestion in the rumen, there was a marked loss of inner parenchymal tissues in AC and LC+AC-treated silages
Evidence for Bound Entangled States with Negative Partial Transpose
We exhibit a two-parameter family of bipartite mixed states , in a
Hilbert space, which are negative under partial transposition
(NPT), but for which we conjecture that no maximally entangled pure states in
can be distilled by local quantum operations and classical
communication (LQ+CC). Evidence for this undistillability is provided by the
result that, for certain states in this family, we cannot extract entanglement
from any arbitrarily large number of copies of using a projection
on . These states are canonical NPT states in the sense that any
bipartite mixed state in any dimension with NPT can be reduced by LQ+CC
operations to an NPT state of the form. We show that the main
question about the distillability of mixed states can be formulated as an open
mathematical question about the properties of composed positive linear maps.Comment: Revtex, 19 pages, 2 eps figures. v2,3: very minor changes, submitted
to Phys. Rev. A. v4: minor typos correcte
Shorter Leukocyte Telomere Length in Midlife Women with Poor Sleep Quality
Background. Accumulating evidence supports leukocyte telomere length (LTL) as a biological marker of cellular aging. Poor sleep is a risk factor for age-related disease; however, the extent to which sleep accounts for variation in LTL is unknown. Methods. The present study examined associations of self-reported sleep duration, onset latency, and subjective quality with LTL in a community-dwelling sample of 245 healthy women in midlife (aged 49–66 years). Results. While sleep duration and onset latency were unrelated to LTL, women reporting poorer sleep quality displayed shorter LTL (r = 0.14, P = 0.03), independent of age, BMI, race, and income (b = 55.48, SE = 27.43, P = 0.04). When analyses were restricted to participants for whom sleep patterns were chronic, poorer sleep quality predicted shorter LTL independent of covariates and perceived psychological stress. Conclusions. This study provides the first evidence that poor sleep quality explains significant variation in LTL, a marker of cellular aging
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