25,140 research outputs found
Symplectic Reduction and Symmetry Algebra in Boundary Chern-Simons theory
We derive the Kac-Moody algebra and Virasoro algebra in Chern-Simons theory
with boundary by using the symplectic reduction method and the Noether
procedures.Comment: References are adde
Role of Exclusive Breastfeeding and S-iga Antibodies Antirotavirus Breast Milk Towards Risk of Acute Rotavirus Diarrhea in Infants Age of 1-6 Months: Do They Corelate to Breastfeeding "Daily Dose" and Antibody Titers?
Exclusive breastfeeding reduces the incidence of diarrhea, especially in children who live in densely populated neighborhood. This study aims to determine the relationship between exclusive breastfeeding and breast milk contains antirotavirus s-IgA antibodies towards risk of acute rotavirus diarrhea in infants aged of 1-6 months. Case-control study design is applied to determine the relationship between exclusive breastfeeding and breast milk contains s-IgA antibodies antirotavirus with risk of acute rotavirus diarrhea. Cases in this study were patients with acute rotavirus diarrhea and controls were patients without acute rotavirus diarrhea. Cases and controls were matched based on age. There were 23 cases and 69 controls. The proportion who received exclusive breastfeeding was 34.8% in cases and 34.4% in controls, with OR of 1.21 (95% CI: 0.45 to 3.28) and p = 0.28. Breast milk contains sIgA antibodies antirotavirus for case was 17.39% and controls was 23.2%, OR was 1.12 (95% CI: 0.29 to 4.29), p = 0.203. In conclusion, exclusive breastfeeding and breast milk contains sIgA antibodies antirotavirus were not associated with risk of acute rotavirus diarrhea in infants 1-6 months. This may be caused by differences in population and demographic studies as well as low of milk sIgA antibody antirotavirus titters. Further research of breastfeeding regardless of antirotavirus containing high antibody titters sIgA is needed
Reply Comment on "Entropy of 2D black holes from counting microstates"
We show that the arguments proposed by Park and Yee against our recent
derivation of the statistical entropy of 2D black holes do not apply to the
case under considerationComment: 3 pages, LaTex file, reply to comment hep-th/991021
Fundamental Limits to Coherent Photon Generation with Solid-State Atomlike Transitions
Coherent generation of indistinguishable single photons is crucial for many
quantum communication and processing protocols. Solid-state realizations of
two-level atomic transitions or three-level spin- systems offer
significant advantages over their atomic counterparts for this purpose, albeit
decoherence can arise due to environmental couplings. One popular approach to
mitigate dephasing is to operate in the weak excitation limit, where excited
state population is minimal and coherently scattered photons dominate over
incoherent emission. Here we probe the coherence of photons produced using
two-level and spin- solid-state systems. We observe that the coupling
of the atomic-like transitions to the vibronic transitions of the crystal
lattice is independent of driving strength and detuning. We apply a polaron
master equation to capture the non-Markovian dynamics of the ground state
vibrational manifolds. These results provide insight into the fundamental
limitations for photon coherence from solid-state quantum emitters, with the
consequence that deterministic single-shot quantum protocols are impossible and
inherently probabilistic approaches must be embraced.Comment: 16 pages [with supplementary information], 8 figure
Observation of Competing Order in a High- Superconductor with Femtosecond Optical Pulses
We present studies of the photoexcited quasiparticle dynamics in
TlBaCaCuO (Tl-2223) using femtosecond optical
techniques. Deep into the superconducting state (below 40 K), a dramatic change
occurs in the temporal dynamics associated with photoexcited quasiparticles
rejoining the condensate. This is suggestive of entry into a coexistence phase
which, as our analysis reveals, opens a gap in the density of states (in
addition to the superconducting gap), and furthermore, competes with
superconductivity resulting in a depression of the superconducting gap.Comment: 5 pages, 3 figure
Mass-Radius Relation for Magnetic White Dwarfs
Recently, several white dwarfs with very strong surface magnetic fields have
been observed. In this paper we explore the possibility that such stars could
have sufficiently strong internal fields to alter their structure. We obtain a
revised white dwarf mass-radius relation in the presence of strong internal
magnetic fields. We first derive the equation of state for a fully degenerate
ideal electron gas in a magnetic field using an Euler-MacLaurin expansion. We
use this to obtain the mass-radius relation for magnetic He, C,
and Fe white dwarfs of uniform composition.Comment: 7 pages, 7 figures and 1 table, To appear in Ap
Non-monotonic temperature dependent transport in graphene grown by Chemical Vapor Deposition
Temperature-dependent resistivity of graphene grown by chemical vapor
deposition (CVD) is investigated. We observe in low mobility CVD graphene
device a strong insulating behavior at low temperatures and a metallic behavior
at high temperatures manifesting a non-monotonic in the temperature dependent
resistivity.This feature is strongly affected by carrier density modulation. To
understand this anomalous temperature dependence, we introduce thermal
activation of charge carriers in electron-hole puddles induced by randomly
distributed charged impurities. Observed temperature evolution of resistivity
is then understood from the competition among thermal activation of charge
carriers, temperature-dependent screening and phonon scattering effects. Our
results imply that the transport property of transferred CVD-grown graphene is
strongly influenced by the details of the environmentComment: 7 pages, 3 figure
Jet trails and Mach cones: The interaction of microquasars with the ISM
A sub-set of microquasars exhibit high peculiar velocity with respect to the
local standard of rest due to the kicks they receive when being born in
supernovae. The interaction between the radio plasma released by microquasar
jets from such high-velocity binaries with the ISM must lead to the production
of trails and bow shocks similar to what is observed in narrow-angle tailed
radio galaxies and pulsar wind nebulae. We present a set of numerical
simulations of this interaction that illuminate the long term dynamical
evolution and the observational properties of these microquasar bow shock
nebulae and trails. We find that this interaction always produces a structure
that consists of a bow shock, a trailing neck, and an expanding bubble. Using
our simulations to model emission, we predict that the shock surrounding the
bubble and the neck should be visible in H{\alpha} emission, the interior of
the bubble should be visible in synchrotron radio emission, and only the bow
shock is likely to be detectable in X-ray emission. We construct an analytic
model for the evolution of the neck and bubble shape and compare this model
with observations of X-ray binary SAX J1712.6-3739.Comment: 33 pages, 13 figures, 1 table; Accepted to Ap
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