2,604 research outputs found
Fixed Charge Ensembles and Parity Breaking Terms
Recently derived results for the exact induced parity-breaking term in 2+1
dimensions at finite temperature are shown to be relevant to the determination
of the free energy for fixed-charge ensembles. The partition functions for
fixed total charge corresponding to massive fermions in the presence of Abelian
and non-Abelian magnetic fields are discussed. We show that the presence of the
induced Chern-Simons term manifests itself in that the free energy depends
strongly on the relation between the external magnetic flux and the value of
the fixed charge.Comment: 10 pages, Revte
Selective binding of synapse-associated protein 97 to GluR-A alpha-amino-5-hydroxy-3-methyl-4-isoxazole propionate receptor subunit is determined by a novel sequence motif.
A family of four closely related PDZ domain-containing membrane-associated guanylate kinase homologues (MAGUKs) is involved in the regulation of the amount and functional state of ionotropic glutamate receptors in excitatory synapses. To understand the mechanisms that determine the specificity of these interactions, we examined the structural basis of the highly selective association between the ionotropic GluR subunit GluR-A and synapse-associated protein 97 (SAP97). The C terminus of GluR-A bound to the PDZ domains of SAP97, but not to those of three related MAGUKs, PSD-93, PSD-95, and SAP102. Experiments with single PDZ domains indicated that the strongest contribution was by the second PDZ domain. Unexpectedly, mutation analysis of the GluR-A C terminus revealed that a tripeptide sequence SSG at position −9 to −11 plays an essential role in this binding, in addition to a C-terminal type I PDZ binding motif (leucine at C terminus and threonine at the −2 position). Analysis of the in vitroMAGUK-binding properties of a GluR-D mutant with a one-residue deletion at the C terminus provides further support for the view that an SSG sequence located N-terminally from a type I PDZ binding motif can mediate selective binding to SAP97 and suggest the existence of a novel variation of the PDZ domain-peptide interaction
Age-related changes to macrophages are detrimental to fracture healing in mice.
The elderly population suffers from higher rates of complications during fracture healing that result in increased morbidity and mortality. Inflammatory dysregulation is associated with increased age and is a contributing factor to the myriad of age-related diseases. Therefore, we investigated age-related changes to an important cellular regulator of inflammation, the macrophage, and the impact on fracture healing outcomes. We demonstrated that old mice (24Â months) have delayed fracture healing with significantly less bone and more cartilage compared to young mice (3Â months). The quantity of infiltrating macrophages into the fracture callus was similar in old and young mice. However, RNA-seq analysis demonstrated distinct differences in the transcriptomes of macrophages derived from the fracture callus of old and young mice, with an up-regulation of M1/pro-inflammatory genes in macrophages from old mice as well as dysregulation of other immune-related genes. Preventing infiltration of the fracture site by macrophages in old mice improved healing outcomes, with significantly more bone in the calluses of treated mice compared to age-matched controls. After preventing infiltration by macrophages, the macrophages remaining within the fracture callus were collected and examined via RNA-seq analysis, and their transcriptome resembled macrophages from young calluses. Taken together, infiltrating macrophages from old mice demonstrate detrimental age-related changes, and depleting infiltrating macrophages can improve fracture healing in old mice
Abelian and Non-Abelian Induced Parity Breaking Terms at Finite Temperature
We compute the exact canonically induced parity breaking part of the
effective action for 2+1 massive fermions in particular Abelian and non Abelian
gauge field backgrounds. The method of computation resorts to the chiral
anomaly of the dimensionally reduced theory.Comment: 13 pages, RevTeX, no figure
AND Protocols Using Only Uniform Shuffles
Secure multi-party computation using a deck of playing cards has been a
subject of research since the "five-card trick" introduced by den Boer in 1989.
One of the main problems in card-based cryptography is to design
committed-format protocols to compute a Boolean AND operation subject to
different runtime and shuffle restrictions by using as few cards as possible.
In this paper, we introduce two AND protocols that use only uniform shuffles.
The first one requires four cards and is a restart-free Las Vegas protocol with
finite expected runtime. The second one requires five cards and always
terminates in finite time.Comment: This paper has appeared at CSR 201
Bound states of neutral particles in external electric fields
Neutral fermions of spin with magnetic moment can interact with
electromagnetic fields through nonminimal coupling. The Dirac--Pauli equation
for such a fermion coupled to a spherically symmetric or central electric field
can be reduced to two simultaneous ordinary differential equations by
separation of variables in spherical coordinates. For a wide variety of central
electric fields, bound-state solutions of critical energy values can be found
analytically. The degeneracy of these energy levels turns out to be numerably
infinite. This reveals the possibility of condensing infinitely many fermions
into a single energy level. For radially constant and radially linear electric
fields, the system of ordinary differential equations can be completely solved,
and all bound-state solutions are obtained in closed forms. The radially
constant field supports scattering solutions as well. For radially linear
fields, more energy levels (in addition to the critical one) are infinitely
degenerate. The simultaneous presence of central magnetic and electric fields
is discussed.Comment: REVTeX, 14 pages, no figur
Storage stability of rapeseed methyl ester stored in a sealed barrel for seven years
Received: March, 31st, 2021 ; Accepted: April, 24th, 2021 ; Published: November 15th, 2021 ; Correspondence: [email protected] stability is one of the main quality parameters related to fatty acid methyl esters
(FAME) biofuels. The deterioration of biofuels´ properties during storage is a more serious issue
than with conventional fuels. In particular, lengthy storage threatens the oxidative stability of
FAME fuels because factors such as the presence of air, elevated temperatures or presence of
metals promote the oxidation process. Consequently, the acceptable storage time for FAME fuels
is generally regarded to be regrettably short, at no more than six to12 months. However, storage
conditions play an important role in determining actual storage stability. This study aimed to
investigate and evaluate any deterioration in the quality of rapeseed methyl ester (RME) fuel that
has been stored for as long as seven years in adequate storage conditions. The fuel was stored in
the dark, contained in a sealed steel barrel in an insulated shipping container outdoors. The
temperature of the container varied with seasonal fluctuation, but the fuel never froze during
storage. The study analysed six key fuel properties of the RME: ester content; water content;
density; kinematic viscosity; oxidation stability index; and acid number. The analyses were
conducted immediately after opening the barrel, and again after two months of storage in a
laboratory. The results were compared to those measured for the fresh fuel, seven years earlier.
The comparison of the results indicate that the fuel quality had suffered no serious deterioration
during the seven-year period
Relativistic shock waves in viscous gluon matter
We solve the relativistic Riemann problem in viscous gluon matter employing a
microscopic parton cascade. We demonstrate the transition from ideal to viscous
shock waves by varying the shear viscosity to entropy density ratio
from zero to infinity. We show that an ratio larger than 0.2 prevents
the development of well-defined shock waves on timescales typical for
ultrarelativistic heavy-ion collisions. Comparisons with viscous hydrodynamic
calculations confirm our findings.Comment: Version as published in PRL 103, 032301 (2009). 4 pages, 4 figure
On the Point-Splitting Method of the Commutator Anomaly of the Gauss Law Operators
We analyze the generalized point-splitting method and Jo's result for the
commutator anomaly. We find that certain classes of general regularization
kernels satisfying integral conditions provide a unique result, which, however
differs from Faddeev's cohomological result.Comment: 16 pages, RevTex, 1 figure + 1 table, uses psbox.te
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