461 research outputs found
Inhomogeneous charged pion condensation phenomenon in the NJL model with quark number and isospin chemical potentials
The properties of two-flavored massive Nambu--Jona-Lasinio model in
(1+1)-dimensional spacetime are investigated in the presence of isospin and
quark number chemical potentials. The consideration is performed in the
large- limit, where is the number of colored quarks. It is shown in
the framework of this model that charged pion condensation phenomenon of dense
quark/hadron isotopically asymmetric matter is rather a spatially inhomogeneous
than a homogeneous one.Comment: 11 pages, 8 figures; version accepted for publication in PRD. arXiv
admin note: text overlap with arXiv:1106.2928, arXiv:1102.407
Superfluid and Pseudo-Goldstone Modes in Three Flavor Crystalline Color Superconductivity
We study the bosonic excitations in the favorite cubic three flavor
crystalline LOFF phases of QCD. We calculate in the Ginzburg-Landau
approximation the masses of the eight pseudo Nambu-Goldstone Bosons (NGB)
present in the low energy theory. We also compute the decay constants of the
massless NGB Goldstones associated to superfluidity as well as those of the
eight pseudo NGB. Differently from the corresponding situation in the
Color-Flavor-Locking phase, we find that meson condensation phases are not
expected in the present scenario.Comment: 10 pages, RevTeX4 class. Section IIIA enlarged, to appear on Phys.
Rev.
Caspase-independent programmed cell death triggers Ca2PO4 deposition in an in vitro model of nephrocalcinosis
We provide evidence of caspase-independent cell death triggering the calcification process in GDNF-silenced HK-2 cells
Cooling of a Compact Star with a LOFF Matter Core
Specific heat and neutrino emissivity due to direct URCA processes for quark
matter in the color superconductive Larkin-Ovchinnikov-Fulde-Ferrell (LOFF)
phase of Quantum-Chromodynamics have been evaluated. The cooling rate of
simplified models of compact stars with a LOFF matter core is estimated.Comment: 3 pages, 1 figure, to appear in the proceedings of the Helmoltz
International Summer School of Theoretical Physics on Dense Matter in Heavy
Ion Collisions and Astrophysics, JINR, Dubna, Russia, 21 Aug - 1 Sep 200
Cell death in the kidney
Apoptotic cell death is usually a response to the cell’s microenvironment. In the kidney, apoptosis contributes to parenchymal cell loss in the course of acute and chronic renal injury, but does not trigger an inflammatory response. What distinguishes necrosis from apoptosis is the rupture of the plasma membrane, so necrotic cell death is accompanied by the release of unprocessed intracellular content, including cellular organelles, which are highly immunogenic proteins. The relative contribution of apoptosis and necrosis to injury varies, depending on the severity of the insult. Regulated cell death may result from immunologically silent apoptosis or from immunogenic necrosis. Recent advances have enhanced the most revolutionary concept of regulated necrosis. Several modalities of regulated necrosis have been described, such as necroptosis, ferroptosis, pyroptosis, and mitochondrial permeability transition-dependent regulated necrosis. We review the different modalities of apoptosis, necrosis, and regulated necrosis in kidney injury, focusing particularly on evidence implicating cell death in ectopic renal calcification. We also review the evidence for the role of cell death in kidney injury, which may pave the way for new therapeutic opportunities
An Experimental Validation of Phase-Based Motion Magnification for Structures with Developing Cracks and Time-Varying Configurations
In this study, Computer Vision and Phase-Based Motion Magnification (PBMM) are validated for continuous Structural Health Monitoring (SHM) purposes. The aim is to identify the exact instant of occurrence for damage or abrupt structural changes from video-extracted, very low amplitude (barely visible) vibrations. The study presents three experimental datasets: a box beam with multiple saw cuts of different lengths and angles, a beam with a full rectangular cross section and a mass added at the tip, and the spar of a prototype High-Aspect-Ratio wing. Both mode-shape- and frequency-based approaches are considered, showing the potential to identify the severity and position of the damage as well A high-definition, high-speed camera and a low-cost commercial alternative have been successfully utilised for these video acquisitions. Finally, the technique is also preliminarily tested for outdoor applications with smartphone cameras
Chiral crossover, deconfinement and quarkyonic matter within a Nambu-Jona Lasinio model with the Polyakov loop
We study the interplay between the chiral and the deconfinement transitions,
both at high temperature and high quark chemical potential, by a non local
Nambu-Jona Lasinio model with the Polyakov loop in the mean field approximation
and requiring neutrality of the ground state. We consider three forms of the
effective potential of the Polyakov loop: two of them with a fixed
deconfinement scale, cases I and II, and the third one with a dependent
scale, case III. In the cases I and II, at high chemical potential and
low temperature the main contribution to the free energy is due to the
Z(3)-neutral three-quark states, mimicking the quarkyonic phase of the large
phase diagram. On the other hand in the case III the quarkyonic window is
shrunk to a small region. Finally we comment on the relations of these results
to lattice studies and on possible common prospects. We also briefly comment on
the coexistence of quarkyonic and color superconductive phases.Comment: 16 pages, 7 figures, RevTeX4. Some typos corrected, references adde
Neutrino emission from compact stars and inhomogeneous color superconductivity
We discuss specific heat and neutrino emissivity due to direct Urca processes
for quark matter in the color superconductive Larkin-Ovchinnikov-Fulde-Ferrell
(LOFF) phase of Quantum-Chromodynamics. We assume that the three light quarks
are in a color and electrically neutral state and interact by a four
fermion Nambu-Jona Lasinio coupling. We study a LOFF state characterized by a
single plane wave for each pairing. From the evaluation of neutrino emissivity
and fermionic specific heat, the cooling rate of simplified models of compact
stars with a quark core in the LOFF state is estimated.Comment: 16 pages, 5 figures, revtex4 style. Version accepted for publication
in Phys. Rev.
A diagrammatic derivation of the meson effective masses in the neutral color-flavor-locked phase of Quantum Chromodynamics
We offer a diagrammatic derivation of the effective masses of the axial
flavor excitations in the electrical and color neutral CFL phase of QCD. In
particular we concentrate on the excitations with the quantum numbers of the
kaons: we show how their effective chemical potentials, responsible of their
Bose-Einstein condensation and found previously on the basis of pure symmetry
arguments, arise at the microscopic level by loop effects. We perform also the
numerical evaluation of the relevant loops in the whole CFL regime
, showing the existence of the enhancement of the
kaon condensation with respect to the lowest order result. Finally we discuss
the role of electrical and color neutrality in the microscopic calculation.Comment: 10 pages, 2 figures, RevTeX4 style. Version accepted for publication
on JHEP. Some minor change in the tex
Modularity map of the network of human cell differentiation
Cell differentiation in multicellular organisms is a complex process whose
mechanism can be understood by a reductionist approach, in which the individual
processes that control the generation of different cell types are identified.
Alternatively, a large scale approach in search of different organizational
features of the growth stages promises to reveal its modular global structure
with the goal of discovering previously unknown relations between cell types.
Here we sort and analyze a large set of scattered data to construct the network
of human cell differentiation (NHCD) based on cell types (nodes) and
differentiation steps (links) from the fertilized egg to a crying baby. We
discover a dynamical law of critical branching, which reveals a fractal
regularity in the modular organization of the network, and allows us to observe
the network at different scales. The emerging picture clearly identifies
clusters of cell types following a hierarchical organization, ranging from
sub-modules to super-modules of specialized tissues and organs on varying
scales. This discovery will allow one to treat the development of a particular
cell function in the context of the complex network of human development as a
whole. Our results point to an integrated large-scale view of the network of
cell types systematically revealing ties between previously unrelated domains
in organ functions.Comment: 32 pages, 7 figure
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